guix.texi 1.2 MB

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  1. \input texinfo
  2. @c -*-texinfo-*-
  3. @c %**start of header
  4. @setfilename guix.info
  5. @documentencoding UTF-8
  6. @settitle GNU Guix Reference Manual
  7. @c %**end of header
  8. @include version.texi
  9. @c Identifier of the OpenPGP key used to sign tarballs and such.
  10. @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
  11. @set OPENPGP-SIGNING-KEY-URL https://sv.gnu.org/people/viewgpg.php?user_id=15145
  12. @c Base URL for downloads.
  13. @set BASE-URL https://ftp.gnu.org/gnu/guix
  14. @c The official substitute server used by default.
  15. @set SUBSTITUTE-SERVER ci.guix.gnu.org
  16. @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
  17. @copying
  18. Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès@*
  19. Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
  20. Copyright @copyright{} 2013 Nikita Karetnikov@*
  21. Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
  22. Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
  23. Copyright @copyright{} 2014 Pierre-Antoine Rault@*
  24. Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
  25. Copyright @copyright{} 2015, 2016, 2017, 2019, 2020, 2021 Leo Famulari@*
  26. Copyright @copyright{} 2015, 2016, 2017, 2018, 2019, 2020 Ricardo Wurmus@*
  27. Copyright @copyright{} 2016 Ben Woodcroft@*
  28. Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
  29. Copyright @copyright{} 2016, 2017, 2018, 2019, 2020, 2021 Efraim Flashner@*
  30. Copyright @copyright{} 2016 John Darrington@*
  31. Copyright @copyright{} 2016, 2017 Nikita Gillmann@*
  32. Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Jan Nieuwenhuizen@*
  33. Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Julien Lepiller@*
  34. Copyright @copyright{} 2016 Alex ter Weele@*
  35. Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
  36. Copyright @copyright{} 2017, 2018, 2019 Clément Lassieur@*
  37. Copyright @copyright{} 2017, 2018, 2020, 2021 Mathieu Othacehe@*
  38. Copyright @copyright{} 2017 Federico Beffa@*
  39. Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
  40. Copyright @copyright{} 2017 Thomas Danckaert@*
  41. Copyright @copyright{} 2017 humanitiesNerd@*
  42. Copyright @copyright{} 2017, 2021 Christopher Lemmer Webber@*
  43. Copyright @copyright{} 2017, 2018, 2019, 2020 Marius Bakke@*
  44. Copyright @copyright{} 2017, 2019, 2020 Hartmut Goebel@*
  45. Copyright @copyright{} 2017, 2019, 2020, 2021 Maxim Cournoyer@*
  46. Copyright @copyright{} 2017, 2018, 2019, 2020 Tobias Geerinckx-Rice@*
  47. Copyright @copyright{} 2017 George Clemmer@*
  48. Copyright @copyright{} 2017 Andy Wingo@*
  49. Copyright @copyright{} 2017, 2018, 2019, 2020 Arun Isaac@*
  50. Copyright @copyright{} 2017 nee@*
  51. Copyright @copyright{} 2018 Rutger Helling@*
  52. Copyright @copyright{} 2018, 2021 Oleg Pykhalov@*
  53. Copyright @copyright{} 2018 Mike Gerwitz@*
  54. Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
  55. Copyright @copyright{} 2018, 2019 Gábor Boskovits@*
  56. Copyright @copyright{} 2018, 2019, 2020 Florian Pelz@*
  57. Copyright @copyright{} 2018 Laura Lazzati@*
  58. Copyright @copyright{} 2018 Alex Vong@*
  59. Copyright @copyright{} 2019 Josh Holland@*
  60. Copyright @copyright{} 2019, 2020 Diego Nicola Barbato@*
  61. Copyright @copyright{} 2019 Ivan Petkov@*
  62. Copyright @copyright{} 2019 Jakob L. Kreuze@*
  63. Copyright @copyright{} 2019 Kyle Andrews@*
  64. Copyright @copyright{} 2019 Alex Griffin@*
  65. Copyright @copyright{} 2019, 2020 Guillaume Le Vaillant@*
  66. Copyright @copyright{} 2020 Leo Prikler@*
  67. Copyright @copyright{} 2019, 2020 Simon Tournier@*
  68. Copyright @copyright{} 2020 Wiktor Żelazny@*
  69. Copyright @copyright{} 2020 Damien Cassou@*
  70. Copyright @copyright{} 2020 Jakub Kądziołka@*
  71. Copyright @copyright{} 2020 Jack Hill@*
  72. Copyright @copyright{} 2020 Naga Malleswari@*
  73. Copyright @copyright{} 2020 Brice Waegeneire@*
  74. Copyright @copyright{} 2020 R Veera Kumar@*
  75. Copyright @copyright{} 2020 Pierre Langlois@*
  76. Copyright @copyright{} 2020 pinoaffe@*
  77. Copyright @copyright{} 2020 André Batista@*
  78. Copyright @copyright{} 2020, 2021 Alexandru-Sergiu Marton@*
  79. Copyright @copyright{} 2020 raingloom@*
  80. Copyright @copyright{} 2020 Daniel Brooks@*
  81. Copyright @copyright{} 2020 John Soo@*
  82. Copyright @copyright{} 2020 Jonathan Brielmaier@*
  83. Copyright @copyright{} 2020 Edgar Vincent@*
  84. Copyright @copyright{} 2021 Maxime Devos@*
  85. Permission is granted to copy, distribute and/or modify this document
  86. under the terms of the GNU Free Documentation License, Version 1.3 or
  87. any later version published by the Free Software Foundation; with no
  88. Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
  89. copy of the license is included in the section entitled ``GNU Free
  90. Documentation License''.
  91. @end copying
  92. @dircategory System administration
  93. @direntry
  94. * Guix: (guix). Manage installed software and system configuration.
  95. * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
  96. * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
  97. * guix pull: (guix)Invoking guix pull. Update the list of available packages.
  98. * guix system: (guix)Invoking guix system. Manage the operating system configuration.
  99. * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
  100. @end direntry
  101. @dircategory Software development
  102. @direntry
  103. * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
  104. * guix build: (guix)Invoking guix build. Building packages.
  105. * guix pack: (guix)Invoking guix pack. Creating binary bundles.
  106. @end direntry
  107. @titlepage
  108. @title GNU Guix Reference Manual
  109. @subtitle Using the GNU Guix Functional Package Manager
  110. @author The GNU Guix Developers
  111. @page
  112. @vskip 0pt plus 1filll
  113. Edition @value{EDITION} @*
  114. @value{UPDATED} @*
  115. @insertcopying
  116. @end titlepage
  117. @contents
  118. @c *********************************************************************
  119. @node Top
  120. @top GNU Guix
  121. This document describes GNU Guix version @value{VERSION}, a functional
  122. package management tool written for the GNU system.
  123. @c TRANSLATORS: You can replace the following paragraph with information on
  124. @c how to join your own translation team and how to report issues with the
  125. @c translation.
  126. This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
  127. GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
  128. Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
  129. Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
  130. Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
  131. would like to translate it in your native language, consider joining
  132. @uref{https://translate.fedoraproject.org/projects/guix/documentation-manual,
  133. Weblate}.
  134. @menu
  135. * Introduction:: What is Guix about?
  136. * Installation:: Installing Guix.
  137. * System Installation:: Installing the whole operating system.
  138. * Getting Started:: Your first steps.
  139. * Package Management:: Package installation, upgrade, etc.
  140. * Channels:: Customizing the package collection.
  141. * Development:: Guix-aided software development.
  142. * Programming Interface:: Using Guix in Scheme.
  143. * Utilities:: Package management commands.
  144. * System Configuration:: Configuring the operating system.
  145. * Documentation:: Browsing software user manuals.
  146. * Installing Debugging Files:: Feeding the debugger.
  147. * Security Updates:: Deploying security fixes quickly.
  148. * Bootstrapping:: GNU/Linux built from scratch.
  149. * Porting:: Targeting another platform or kernel.
  150. * Contributing:: Your help needed!
  151. * Acknowledgments:: Thanks!
  152. * GNU Free Documentation License:: The license of this manual.
  153. * Concept Index:: Concepts.
  154. * Programming Index:: Data types, functions, and variables.
  155. @detailmenu
  156. --- The Detailed Node Listing ---
  157. Introduction
  158. * Managing Software the Guix Way:: What's special.
  159. * GNU Distribution:: The packages and tools.
  160. Installation
  161. * Binary Installation:: Getting Guix running in no time!
  162. * Requirements:: Software needed to build and run Guix.
  163. * Running the Test Suite:: Testing Guix.
  164. * Setting Up the Daemon:: Preparing the build daemon's environment.
  165. * Invoking guix-daemon:: Running the build daemon.
  166. * Application Setup:: Application-specific setup.
  167. * Upgrading Guix:: Upgrading Guix and its build daemon.
  168. Setting Up the Daemon
  169. * Build Environment Setup:: Preparing the isolated build environment.
  170. * Daemon Offload Setup:: Offloading builds to remote machines.
  171. * SELinux Support:: Using an SELinux policy for the daemon.
  172. System Installation
  173. * Limitations:: What you can expect.
  174. * Hardware Considerations:: Supported hardware.
  175. * USB Stick and DVD Installation:: Preparing the installation medium.
  176. * Preparing for Installation:: Networking, partitioning, etc.
  177. * Guided Graphical Installation:: Easy graphical installation.
  178. * Manual Installation:: Manual installation for wizards.
  179. * After System Installation:: When installation succeeded.
  180. * Installing Guix in a VM:: Guix System playground.
  181. * Building the Installation Image:: How this comes to be.
  182. Manual Installation
  183. * Keyboard Layout and Networking and Partitioning:: Initial setup.
  184. * Proceeding with the Installation:: Installing.
  185. Package Management
  186. * Features:: How Guix will make your life brighter.
  187. * Invoking guix package:: Package installation, removal, etc.
  188. * Substitutes:: Downloading pre-built binaries.
  189. * Packages with Multiple Outputs:: Single source package, multiple outputs.
  190. * Invoking guix gc:: Running the garbage collector.
  191. * Invoking guix pull:: Fetching the latest Guix and distribution.
  192. * Invoking guix time-machine:: Running an older revision of Guix.
  193. * Inferiors:: Interacting with another revision of Guix.
  194. * Invoking guix describe:: Display information about your Guix revision.
  195. * Invoking guix archive:: Exporting and importing store files.
  196. Substitutes
  197. * Official Substitute Server:: One particular source of substitutes.
  198. * Substitute Server Authorization:: How to enable or disable substitutes.
  199. * Getting Substitutes from Other Servers:: Substitute diversity.
  200. * Substitute Authentication:: How Guix verifies substitutes.
  201. * Proxy Settings:: How to get substitutes via proxy.
  202. * Substitution Failure:: What happens when substitution fails.
  203. * On Trusting Binaries:: How can you trust that binary blob?
  204. Channels
  205. * Specifying Additional Channels:: Extending the package collection.
  206. * Using a Custom Guix Channel:: Using a customized Guix.
  207. * Replicating Guix:: Running the @emph{exact same} Guix.
  208. * Channel Authentication:: How Guix verifies what it fetches.
  209. * Creating a Channel:: How to write your custom channel.
  210. * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
  211. * Declaring Channel Dependencies:: How to depend on other channels.
  212. * Specifying Channel Authorizations:: Defining channel authors authorizations.
  213. * Primary URL:: Distinguishing mirror to original.
  214. * Writing Channel News:: Communicating information to channel's users.
  215. * Channels with Substitutes:: Using channels with available substitutes.
  216. Development
  217. * Invoking guix environment:: Setting up development environments.
  218. * Invoking guix pack:: Creating software bundles.
  219. * The GCC toolchain:: Working with languages supported by GCC.
  220. * Invoking guix git authenticate:: Authenticating Git repositories.
  221. Programming Interface
  222. * Package Modules:: Packages from the programmer's viewpoint.
  223. * Defining Packages:: Defining new packages.
  224. * Defining Package Variants:: Customizing packages.
  225. * Build Systems:: Specifying how packages are built.
  226. * Build Phases:: Phases of the build process of a package.
  227. * Build Utilities:: Helpers for your package definitions and more.
  228. * The Store:: Manipulating the package store.
  229. * Derivations:: Low-level interface to package derivations.
  230. * The Store Monad:: Purely functional interface to the store.
  231. * G-Expressions:: Manipulating build expressions.
  232. * Invoking guix repl:: Programming Guix in Guile.
  233. Defining Packages
  234. * package Reference:: The package data type.
  235. * origin Reference:: The origin data type.
  236. Utilities
  237. * Invoking guix build:: Building packages from the command line.
  238. * Invoking guix edit:: Editing package definitions.
  239. * Invoking guix download:: Downloading a file and printing its hash.
  240. * Invoking guix hash:: Computing the cryptographic hash of a file.
  241. * Invoking guix import:: Importing package definitions.
  242. * Invoking guix refresh:: Updating package definitions.
  243. * Invoking guix lint:: Finding errors in package definitions.
  244. * Invoking guix size:: Profiling disk usage.
  245. * Invoking guix graph:: Visualizing the graph of packages.
  246. * Invoking guix publish:: Sharing substitutes.
  247. * Invoking guix challenge:: Challenging substitute servers.
  248. * Invoking guix copy:: Copying to and from a remote store.
  249. * Invoking guix container:: Process isolation.
  250. * Invoking guix weather:: Assessing substitute availability.
  251. * Invoking guix processes:: Listing client processes.
  252. Invoking @command{guix build}
  253. * Common Build Options:: Build options for most commands.
  254. * Package Transformation Options:: Creating variants of packages.
  255. * Additional Build Options:: Options specific to 'guix build'.
  256. * Debugging Build Failures:: Real life packaging experience.
  257. System Configuration
  258. * Using the Configuration System:: Customizing your GNU system.
  259. * operating-system Reference:: Detail of operating-system declarations.
  260. * File Systems:: Configuring file system mounts.
  261. * Mapped Devices:: Block device extra processing.
  262. * User Accounts:: Specifying user accounts.
  263. * Keyboard Layout:: How the system interprets key strokes.
  264. * Locales:: Language and cultural convention settings.
  265. * Services:: Specifying system services.
  266. * Setuid Programs:: Programs running with root privileges.
  267. * X.509 Certificates:: Authenticating HTTPS servers.
  268. * Name Service Switch:: Configuring libc's name service switch.
  269. * Initial RAM Disk:: Linux-Libre bootstrapping.
  270. * Bootloader Configuration:: Configuring the boot loader.
  271. * Invoking guix system:: Instantiating a system configuration.
  272. * Invoking guix deploy:: Deploying a system configuration to a remote host.
  273. * Running Guix in a VM:: How to run Guix System in a virtual machine.
  274. * Defining Services:: Adding new service definitions.
  275. Services
  276. * Base Services:: Essential system services.
  277. * Scheduled Job Execution:: The mcron service.
  278. * Log Rotation:: The rottlog service.
  279. * Networking Services:: Network setup, SSH daemon, etc.
  280. * Unattended Upgrades:: Automated system upgrades.
  281. * X Window:: Graphical display.
  282. * Printing Services:: Local and remote printer support.
  283. * Desktop Services:: D-Bus and desktop services.
  284. * Sound Services:: ALSA and Pulseaudio services.
  285. * Database Services:: SQL databases, key-value stores, etc.
  286. * Mail Services:: IMAP, POP3, SMTP, and all that.
  287. * Messaging Services:: Messaging services.
  288. * Telephony Services:: Telephony services.
  289. * Monitoring Services:: Monitoring services.
  290. * Kerberos Services:: Kerberos services.
  291. * LDAP Services:: LDAP services.
  292. * Web Services:: Web servers.
  293. * Certificate Services:: TLS certificates via Let's Encrypt.
  294. * DNS Services:: DNS daemons.
  295. * VPN Services:: VPN daemons.
  296. * Network File System:: NFS related services.
  297. * Continuous Integration:: The Cuirass service.
  298. * Power Management Services:: Extending battery life.
  299. * Audio Services:: The MPD.
  300. * Virtualization Services:: Virtualization services.
  301. * Version Control Services:: Providing remote access to Git repositories.
  302. * Game Services:: Game servers.
  303. * PAM Mount Service:: Service to mount volumes when logging in.
  304. * Guix Services:: Services relating specifically to Guix.
  305. * Linux Services:: Services tied to the Linux kernel.
  306. * Hurd Services:: Services specific for a Hurd System.
  307. * Miscellaneous Services:: Other services.
  308. Defining Services
  309. * Service Composition:: The model for composing services.
  310. * Service Types and Services:: Types and services.
  311. * Service Reference:: API reference.
  312. * Shepherd Services:: A particular type of service.
  313. Installing Debugging Files
  314. * Separate Debug Info:: Installing 'debug' outputs.
  315. * Rebuilding Debug Info:: Building missing debug info.
  316. Bootstrapping
  317. * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
  318. * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
  319. @end detailmenu
  320. @end menu
  321. @c *********************************************************************
  322. @node Introduction
  323. @chapter Introduction
  324. @cindex purpose
  325. GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
  326. using the international phonetic alphabet (IPA).} is a package
  327. management tool for and distribution of the GNU system.
  328. Guix makes it easy for unprivileged
  329. users to install, upgrade, or remove software packages, to roll back to a
  330. previous package set, to build packages from source, and generally
  331. assists with the creation and maintenance of software environments.
  332. @cindex Guix System
  333. @cindex GuixSD, now Guix System
  334. @cindex Guix System Distribution, now Guix System
  335. You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
  336. complements the available tools without interference (@pxref{Installation}),
  337. or you can use it as a standalone operating system distribution,
  338. @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
  339. System Distribution'' or ``GuixSD''. We now consider it makes more sense to
  340. group everything under the ``Guix'' banner since, after all, Guix System is
  341. readily available through the @command{guix system} command, even if you're
  342. using a different distro underneath!}. @xref{GNU Distribution}.
  343. @menu
  344. * Managing Software the Guix Way:: What's special.
  345. * GNU Distribution:: The packages and tools.
  346. @end menu
  347. @node Managing Software the Guix Way
  348. @section Managing Software the Guix Way
  349. @cindex user interfaces
  350. Guix provides a command-line package management interface
  351. (@pxref{Package Management}), tools to help with software development
  352. (@pxref{Development}), command-line utilities for more advanced usage
  353. (@pxref{Utilities}), as well as Scheme programming interfaces
  354. (@pxref{Programming Interface}).
  355. @cindex build daemon
  356. Its @dfn{build daemon} is responsible for building packages on behalf of
  357. users (@pxref{Setting Up the Daemon}) and for downloading pre-built
  358. binaries from authorized sources (@pxref{Substitutes}).
  359. @cindex extensibility of the distribution
  360. @cindex customization, of packages
  361. Guix includes package definitions for many GNU and non-GNU packages, all
  362. of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
  363. user's computing freedom}. It is @emph{extensible}: users can write
  364. their own package definitions (@pxref{Defining Packages}) and make them
  365. available as independent package modules (@pxref{Package Modules}). It
  366. is also @emph{customizable}: users can @emph{derive} specialized package
  367. definitions from existing ones, including from the command line
  368. (@pxref{Package Transformation Options}).
  369. @cindex functional package management
  370. @cindex isolation
  371. Under the hood, Guix implements the @dfn{functional package management}
  372. discipline pioneered by Nix (@pxref{Acknowledgments}).
  373. In Guix, the package build and installation process is seen
  374. as a @emph{function}, in the mathematical sense. That function takes inputs,
  375. such as build scripts, a compiler, and libraries, and
  376. returns an installed package. As a pure function, its result depends
  377. solely on its inputs---for instance, it cannot refer to software or
  378. scripts that were not explicitly passed as inputs. A build function
  379. always produces the same result when passed a given set of inputs. It
  380. cannot alter the environment of the running system in
  381. any way; for instance, it cannot create, modify, or delete files outside
  382. of its build and installation directories. This is achieved by running
  383. build processes in isolated environments (or @dfn{containers}), where only their
  384. explicit inputs are visible.
  385. @cindex store
  386. The result of package build functions is @dfn{cached} in the file
  387. system, in a special directory called @dfn{the store} (@pxref{The
  388. Store}). Each package is installed in a directory of its own in the
  389. store---by default under @file{/gnu/store}. The directory name contains
  390. a hash of all the inputs used to build that package; thus, changing an
  391. input yields a different directory name.
  392. This approach is the foundation for the salient features of Guix: support
  393. for transactional package upgrade and rollback, per-user installation, and
  394. garbage collection of packages (@pxref{Features}).
  395. @node GNU Distribution
  396. @section GNU Distribution
  397. @cindex Guix System
  398. Guix comes with a distribution of the GNU system consisting entirely of
  399. free software@footnote{The term ``free'' here refers to the
  400. @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
  401. users of that software}.}. The
  402. distribution can be installed on its own (@pxref{System Installation}),
  403. but it is also possible to install Guix as a package manager on top of
  404. an installed GNU/Linux system (@pxref{Installation}). When we need to
  405. distinguish between the two, we refer to the standalone distribution as
  406. Guix@tie{}System.
  407. The distribution provides core GNU packages such as GNU libc, GCC, and
  408. Binutils, as well as many GNU and non-GNU applications. The complete
  409. list of available packages can be browsed
  410. @url{https://www.gnu.org/software/guix/packages,on-line} or by
  411. running @command{guix package} (@pxref{Invoking guix package}):
  412. @example
  413. guix package --list-available
  414. @end example
  415. Our goal is to provide a practical 100% free software distribution of
  416. Linux-based and other variants of GNU, with a focus on the promotion and
  417. tight integration of GNU components, and an emphasis on programs and
  418. tools that help users exert that freedom.
  419. Packages are currently available on the following platforms:
  420. @table @code
  421. @item x86_64-linux
  422. Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
  423. @item i686-linux
  424. Intel 32-bit architecture (IA32), Linux-Libre kernel.
  425. @item armhf-linux
  426. ARMv7-A architecture with hard float, Thumb-2 and NEON,
  427. using the EABI hard-float application binary interface (ABI),
  428. and Linux-Libre kernel.
  429. @item aarch64-linux
  430. little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
  431. @item i586-gnu
  432. @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
  433. (IA32).
  434. This configuration is experimental and under development. The easiest
  435. way for you to give it a try is by setting up an instance of
  436. @code{hurd-vm-service-type} on your GNU/Linux machine
  437. (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
  438. @xref{Contributing}, on how to help!
  439. @item mips64el-linux (deprecated)
  440. little-endian 64-bit MIPS processors, specifically the Loongson series,
  441. n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
  442. supported; in particular, there is no ongoing work to ensure that this
  443. architecture still works. Should someone decide they wish to revive this
  444. architecture then the code is still available.
  445. @end table
  446. With Guix@tie{}System, you @emph{declare} all aspects of the operating system
  447. configuration and Guix takes care of instantiating the configuration in a
  448. transactional, reproducible, and stateless fashion (@pxref{System
  449. Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
  450. initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
  451. Manual}), the well-known GNU utilities and tool chain, as well as the
  452. graphical environment or system services of your choice.
  453. Guix System is available on all the above platforms except
  454. @code{mips64el-linux}.
  455. @noindent
  456. For information on porting to other architectures or kernels,
  457. @pxref{Porting}.
  458. Building this distribution is a cooperative effort, and you are invited
  459. to join! @xref{Contributing}, for information about how you can help.
  460. @c *********************************************************************
  461. @node Installation
  462. @chapter Installation
  463. @cindex installing Guix
  464. @quotation Note
  465. We recommend the use of this
  466. @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
  467. shell installer script} to install Guix on top of a running GNU/Linux system,
  468. thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
  469. with the installation of the package manager, which can be done on top of a
  470. running GNU/Linux system. If, instead, you want to install the complete GNU
  471. operating system, @pxref{System Installation}.} The script automates the
  472. download, installation, and initial configuration of Guix. It should be run
  473. as the root user.
  474. @end quotation
  475. @cindex foreign distro
  476. @cindex directories related to foreign distro
  477. When installed on a foreign distro, GNU@tie{}Guix complements the available
  478. tools without interference. Its data lives exclusively in two directories,
  479. usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
  480. such as @file{/etc}, are left untouched.
  481. Once installed, Guix can be updated by running @command{guix pull}
  482. (@pxref{Invoking guix pull}).
  483. If you prefer to perform the installation steps manually or want to tweak
  484. them, you may find the following subsections useful. They describe the
  485. software requirements of Guix, as well as how to install it manually and get
  486. ready to use it.
  487. @menu
  488. * Binary Installation:: Getting Guix running in no time!
  489. * Requirements:: Software needed to build and run Guix.
  490. * Running the Test Suite:: Testing Guix.
  491. * Setting Up the Daemon:: Preparing the build daemon's environment.
  492. * Invoking guix-daemon:: Running the build daemon.
  493. * Application Setup:: Application-specific setup.
  494. * Upgrading Guix:: Upgrading Guix and its build daemon.
  495. @end menu
  496. @node Binary Installation
  497. @section Binary Installation
  498. @cindex installing Guix from binaries
  499. @cindex installer script
  500. This section describes how to install Guix on an arbitrary system from a
  501. self-contained tarball providing binaries for Guix and for all its
  502. dependencies. This is often quicker than installing from source, which
  503. is described in the next sections. The only requirement is to have
  504. GNU@tie{}tar and Xz.
  505. @c Note duplicated from the ``Installation'' node.
  506. @quotation Note
  507. We recommend the use of this
  508. @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
  509. shell installer script}. The script automates the download, installation, and
  510. initial configuration steps described below. It should be run as the root
  511. user. As root, you can thus run this:
  512. @example
  513. cd /tmp
  514. wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
  515. chmod +x guix-install.sh
  516. ./guix-install.sh
  517. @end example
  518. When you're done, @pxref{Application Setup} for extra configuration you
  519. might need, and @ref{Getting Started} for your first steps!
  520. @end quotation
  521. Installing goes along these lines:
  522. @enumerate
  523. @item
  524. @cindex downloading Guix binary
  525. Download the binary tarball from
  526. @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
  527. where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
  528. @code{i686} (32-bits) machine already running the kernel Linux, and so on
  529. (@pxref{GNU Distribution}).
  530. @c The following is somewhat duplicated in ``System Installation''.
  531. Make sure to download the associated @file{.sig} file and to verify the
  532. authenticity of the tarball against it, along these lines:
  533. @example
  534. $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
  535. $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
  536. @end example
  537. If that command fails because you do not have the required public key,
  538. then run this command to import it:
  539. @example
  540. $ wget @value{OPENPGP-SIGNING-KEY-URL} \
  541. -qO - | gpg --import -
  542. @end example
  543. @noindent
  544. and rerun the @code{gpg --verify} command.
  545. Take note that a warning like ``This key is not certified with a trusted
  546. signature!'' is normal.
  547. @c end authentication part
  548. @item
  549. Now, you need to become the @code{root} user. Depending on your distribution,
  550. you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
  551. @example
  552. # cd /tmp
  553. # tar --warning=no-timestamp -xf \
  554. /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
  555. # mv var/guix /var/ && mv gnu /
  556. @end example
  557. This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
  558. The latter contains a ready-to-use profile for @code{root} (see next
  559. step).
  560. Do @emph{not} unpack the tarball on a working Guix system since that
  561. would overwrite its own essential files.
  562. The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
  563. not emit warnings about ``implausibly old time stamps'' (such
  564. warnings were triggered by GNU@tie{}tar 1.26 and older; recent
  565. versions are fine).
  566. They stem from the fact that all the
  567. files in the archive have their modification time set to 1 (which
  568. means January 1st, 1970). This is done on purpose to make sure the
  569. archive content is independent of its creation time, thus making it
  570. reproducible.
  571. @item
  572. Make the profile available under @file{~root/.config/guix/current}, which is
  573. where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
  574. @example
  575. # mkdir -p ~root/.config/guix
  576. # ln -sf /var/guix/profiles/per-user/root/current-guix \
  577. ~root/.config/guix/current
  578. @end example
  579. Source @file{etc/profile} to augment @env{PATH} and other relevant
  580. environment variables:
  581. @example
  582. # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
  583. source $GUIX_PROFILE/etc/profile
  584. @end example
  585. @item
  586. Create the group and user accounts for build users as explained below
  587. (@pxref{Build Environment Setup}).
  588. @item
  589. Run the daemon, and set it to automatically start on boot.
  590. If your host distro uses the systemd init system, this can be achieved
  591. with these commands:
  592. @c Versions of systemd that supported symlinked service files are not
  593. @c yet widely deployed, so we should suggest that users copy the service
  594. @c files into place.
  595. @c
  596. @c See this thread for more information:
  597. @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
  598. @example
  599. # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
  600. ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
  601. /etc/systemd/system/
  602. # systemctl enable --now gnu-store.mount guix-daemon
  603. @end example
  604. If your host distro uses the Upstart init system:
  605. @example
  606. # initctl reload-configuration
  607. # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
  608. /etc/init/
  609. # start guix-daemon
  610. @end example
  611. Otherwise, you can still start the daemon manually with:
  612. @example
  613. # ~root/.config/guix/current/bin/guix-daemon \
  614. --build-users-group=guixbuild
  615. @end example
  616. @item
  617. Make the @command{guix} command available to other users on the machine,
  618. for instance with:
  619. @example
  620. # mkdir -p /usr/local/bin
  621. # cd /usr/local/bin
  622. # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
  623. @end example
  624. It is also a good idea to make the Info version of this manual available
  625. there:
  626. @example
  627. # mkdir -p /usr/local/share/info
  628. # cd /usr/local/share/info
  629. # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
  630. do ln -s $i ; done
  631. @end example
  632. That way, assuming @file{/usr/local/share/info} is in the search path,
  633. running @command{info guix} will open this manual (@pxref{Other Info
  634. Directories,,, texinfo, GNU Texinfo}, for more details on changing the
  635. Info search path).
  636. @item
  637. @cindex substitutes, authorization thereof
  638. To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
  639. (@pxref{Substitutes}), authorize them:
  640. @example
  641. # guix archive --authorize < \
  642. ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
  643. @end example
  644. @item
  645. Each user may need to perform a few additional steps to make their Guix
  646. environment ready for use, @pxref{Application Setup}.
  647. @end enumerate
  648. Voilà, the installation is complete!
  649. You can confirm that Guix is working by installing a sample package into
  650. the root profile:
  651. @example
  652. # guix install hello
  653. @end example
  654. The binary installation tarball can be (re)produced and verified simply
  655. by running the following command in the Guix source tree:
  656. @example
  657. make guix-binary.@var{system}.tar.xz
  658. @end example
  659. @noindent
  660. ...@: which, in turn, runs:
  661. @example
  662. guix pack -s @var{system} --localstatedir \
  663. --profile-name=current-guix guix
  664. @end example
  665. @xref{Invoking guix pack}, for more info on this handy tool.
  666. @node Requirements
  667. @section Requirements
  668. This section lists requirements when building Guix from source. The
  669. build procedure for Guix is the same as for other GNU software, and is
  670. not covered here. Please see the files @file{README} and @file{INSTALL}
  671. in the Guix source tree for additional details.
  672. @cindex official website
  673. GNU Guix is available for download from its website at
  674. @url{https://www.gnu.org/software/guix/}.
  675. GNU Guix depends on the following packages:
  676. @itemize
  677. @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
  678. 2.2.x;
  679. @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
  680. 0.1.0 or later;
  681. @item
  682. @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
  683. (@pxref{Guile Preparations, how to install the GnuTLS bindings for
  684. Guile,, gnutls-guile, GnuTLS-Guile});
  685. @item
  686. @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
  687. or later;
  688. @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib},
  689. version 0.1.0 or later;
  690. @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
  691. @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
  692. @item
  693. @c FIXME: Specify a version number once a release has been made.
  694. @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
  695. or later;
  696. @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
  697. 4.3.0 or later;
  698. @item @url{https://www.gnu.org/software/make/, GNU Make}.
  699. @end itemize
  700. The following dependencies are optional:
  701. @itemize
  702. @item
  703. @c Note: We need at least 0.13.0 for #:nodelay.
  704. Support for build offloading (@pxref{Daemon Offload Setup}) and
  705. @command{guix copy} (@pxref{Invoking guix copy}) depends on
  706. @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
  707. version 0.13.0 or later.
  708. @item
  709. @uref{https://notabug.org/guile-zstd/guile-zstd, Guile-zstd}, for zstd
  710. compression and decompression in @command{guix publish} and for
  711. substitutes (@pxref{Invoking guix publish}).
  712. @item
  713. @uref{https://ngyro.com/software/guile-semver.html, Guile-Semver} for
  714. the @code{crate} importer (@pxref{Invoking guix import}).
  715. @item
  716. @uref{https://www.nongnu.org/guile-lib/doc/ref/htmlprag/, Guile-Lib} for
  717. the @code{go} importer (@pxref{Invoking guix import}) and for some of
  718. the ``updaters'' (@pxref{Invoking guix refresh}).
  719. @item
  720. When @url{http://www.bzip.org, libbz2} is available,
  721. @command{guix-daemon} can use it to compress build logs.
  722. @end itemize
  723. Unless @option{--disable-daemon} was passed to @command{configure}, the
  724. following packages are also needed:
  725. @itemize
  726. @item @url{https://gnupg.org/, GNU libgcrypt};
  727. @item @url{https://sqlite.org, SQLite 3};
  728. @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
  729. C++11 standard.
  730. @end itemize
  731. @cindex state directory
  732. When configuring Guix on a system that already has a Guix installation,
  733. be sure to specify the same state directory as the existing installation
  734. using the @option{--localstatedir} option of the @command{configure}
  735. script (@pxref{Directory Variables, @code{localstatedir},, standards,
  736. GNU Coding Standards}). Usually, this @var{localstatedir} option is
  737. set to the value @file{/var}. The @command{configure} script protects
  738. against unintended misconfiguration of @var{localstatedir} so you do not
  739. inadvertently corrupt your store (@pxref{The Store}).
  740. @node Running the Test Suite
  741. @section Running the Test Suite
  742. @cindex test suite
  743. After a successful @command{configure} and @code{make} run, it is a good
  744. idea to run the test suite. It can help catch issues with the setup or
  745. environment, or bugs in Guix itself---and really, reporting test
  746. failures is a good way to help improve the software. To run the test
  747. suite, type:
  748. @example
  749. make check
  750. @end example
  751. Test cases can run in parallel: you can use the @code{-j} option of
  752. GNU@tie{}make to speed things up. The first run may take a few minutes
  753. on a recent machine; subsequent runs will be faster because the store
  754. that is created for test purposes will already have various things in
  755. cache.
  756. It is also possible to run a subset of the tests by defining the
  757. @code{TESTS} makefile variable as in this example:
  758. @example
  759. make check TESTS="tests/store.scm tests/cpio.scm"
  760. @end example
  761. By default, tests results are displayed at a file level. In order to
  762. see the details of every individual test cases, it is possible to define
  763. the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
  764. @example
  765. make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
  766. @end example
  767. The underlying SRFI 64 custom Automake test driver used for the 'check'
  768. test suite (located at @file{build-aux/test-driver.scm}) also allows
  769. selecting which test cases to run at a finer level, via its
  770. @option{--select} and @option{--exclude} options. Here's an example, to
  771. run all the test cases from the @file{tests/packages.scm} test file
  772. whose names start with ``transaction-upgrade-entry'':
  773. @example
  774. export SCM_LOG_DRIVER_FLAGS="--select=^transaction-upgrade-entry"
  775. make check TESTS="tests/packages.scm"
  776. @end example
  777. Those wishing to inspect the results of failed tests directly from the
  778. command line can add the @option{--errors-only=yes} option to the
  779. @code{SCM_LOG_DRIVER_FLAGS} makefile variable and set the @code{VERBOSE}
  780. Automake makefile variable, as in:
  781. @example
  782. make check SCM_LOG_DRIVER_FLAGS="--brief=no --errors-only=yes" VERBOSE=1
  783. @end example
  784. The @option{--show-duration=yes} option can be used to print the
  785. duration of the individual test cases, when used in combination with
  786. @option{--brief=no}:
  787. @example
  788. make check SCM_LOG_DRIVER_FLAGS="--brief=no --show-duration=yes"
  789. @end example
  790. @xref{Parallel Test Harness,,,automake,GNU Automake} for more
  791. information about the Automake Parallel Test Harness.
  792. Upon failure, please email @email{bug-guix@@gnu.org} and attach the
  793. @file{test-suite.log} file. Please specify the Guix version being used
  794. as well as version numbers of the dependencies (@pxref{Requirements}) in
  795. your message.
  796. Guix also comes with a whole-system test suite that tests complete
  797. Guix System instances. It can only run on systems where
  798. Guix is already installed, using:
  799. @example
  800. make check-system
  801. @end example
  802. @noindent
  803. or, again, by defining @code{TESTS} to select a subset of tests to run:
  804. @example
  805. make check-system TESTS="basic mcron"
  806. @end example
  807. These system tests are defined in the @code{(gnu tests @dots{})}
  808. modules. They work by running the operating systems under test with
  809. lightweight instrumentation in a virtual machine (VM). They can be
  810. computationally intensive or rather cheap, depending on whether
  811. substitutes are available for their dependencies (@pxref{Substitutes}).
  812. Some of them require a lot of storage space to hold VM images.
  813. Again in case of test failures, please send @email{bug-guix@@gnu.org}
  814. all the details.
  815. @node Setting Up the Daemon
  816. @section Setting Up the Daemon
  817. @cindex daemon
  818. Operations such as building a package or running the garbage collector
  819. are all performed by a specialized process, the @dfn{build daemon}, on
  820. behalf of clients. Only the daemon may access the store and its
  821. associated database. Thus, any operation that manipulates the store
  822. goes through the daemon. For instance, command-line tools such as
  823. @command{guix package} and @command{guix build} communicate with the
  824. daemon (@i{via} remote procedure calls) to instruct it what to do.
  825. The following sections explain how to prepare the build daemon's
  826. environment. See also @ref{Substitutes}, for information on how to allow
  827. the daemon to download pre-built binaries.
  828. @menu
  829. * Build Environment Setup:: Preparing the isolated build environment.
  830. * Daemon Offload Setup:: Offloading builds to remote machines.
  831. * SELinux Support:: Using an SELinux policy for the daemon.
  832. @end menu
  833. @node Build Environment Setup
  834. @subsection Build Environment Setup
  835. @cindex build environment
  836. In a standard multi-user setup, Guix and its daemon---the
  837. @command{guix-daemon} program---are installed by the system
  838. administrator; @file{/gnu/store} is owned by @code{root} and
  839. @command{guix-daemon} runs as @code{root}. Unprivileged users may use
  840. Guix tools to build packages or otherwise access the store, and the
  841. daemon will do it on their behalf, ensuring that the store is kept in a
  842. consistent state, and allowing built packages to be shared among users.
  843. @cindex build users
  844. When @command{guix-daemon} runs as @code{root}, you may not want package
  845. build processes themselves to run as @code{root} too, for obvious
  846. security reasons. To avoid that, a special pool of @dfn{build users}
  847. should be created for use by build processes started by the daemon.
  848. These build users need not have a shell and a home directory: they will
  849. just be used when the daemon drops @code{root} privileges in build
  850. processes. Having several such users allows the daemon to launch
  851. distinct build processes under separate UIDs, which guarantees that they
  852. do not interfere with each other---an essential feature since builds are
  853. regarded as pure functions (@pxref{Introduction}).
  854. On a GNU/Linux system, a build user pool may be created like this (using
  855. Bash syntax and the @code{shadow} commands):
  856. @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
  857. @c for why `-G' is needed.
  858. @example
  859. # groupadd --system guixbuild
  860. # for i in `seq -w 1 10`;
  861. do
  862. useradd -g guixbuild -G guixbuild \
  863. -d /var/empty -s `which nologin` \
  864. -c "Guix build user $i" --system \
  865. guixbuilder$i;
  866. done
  867. @end example
  868. @noindent
  869. The number of build users determines how many build jobs may run in
  870. parallel, as specified by the @option{--max-jobs} option
  871. (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
  872. @command{guix system vm} and related commands, you may need to add the
  873. build users to the @code{kvm} group so they can access @file{/dev/kvm},
  874. using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
  875. (@pxref{Invoking guix system}).
  876. The @code{guix-daemon} program may then be run as @code{root} with the
  877. following command@footnote{If your machine uses the systemd init system,
  878. dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
  879. file in @file{/etc/systemd/system} will ensure that
  880. @command{guix-daemon} is automatically started. Similarly, if your
  881. machine uses the Upstart init system, drop the
  882. @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
  883. file in @file{/etc/init}.}:
  884. @example
  885. # guix-daemon --build-users-group=guixbuild
  886. @end example
  887. @cindex chroot
  888. @noindent
  889. This way, the daemon starts build processes in a chroot, under one of
  890. the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
  891. environment contains nothing but:
  892. @c Keep this list in sync with libstore/build.cc! -----------------------
  893. @itemize
  894. @item
  895. a minimal @code{/dev} directory, created mostly independently from the
  896. host @code{/dev}@footnote{``Mostly'', because while the set of files
  897. that appear in the chroot's @code{/dev} is fixed, most of these files
  898. can only be created if the host has them.};
  899. @item
  900. the @code{/proc} directory; it only shows the processes of the container
  901. since a separate PID name space is used;
  902. @item
  903. @file{/etc/passwd} with an entry for the current user and an entry for
  904. user @file{nobody};
  905. @item
  906. @file{/etc/group} with an entry for the user's group;
  907. @item
  908. @file{/etc/hosts} with an entry that maps @code{localhost} to
  909. @code{127.0.0.1};
  910. @item
  911. a writable @file{/tmp} directory.
  912. @end itemize
  913. You can influence the directory where the daemon stores build trees
  914. @i{via} the @env{TMPDIR} environment variable. However, the build tree
  915. within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
  916. where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
  917. This way, the value of @env{TMPDIR} does not leak inside build
  918. environments, which avoids discrepancies in cases where build processes
  919. capture the name of their build tree.
  920. @vindex http_proxy
  921. @vindex https_proxy
  922. The daemon also honors the @env{http_proxy} and @env{https_proxy}
  923. environment variables for HTTP and HTTPS downloads it performs, be it
  924. for fixed-output derivations (@pxref{Derivations}) or for substitutes
  925. (@pxref{Substitutes}).
  926. If you are installing Guix as an unprivileged user, it is still possible
  927. to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
  928. However, build processes will not be isolated from one another, and not
  929. from the rest of the system. Thus, build processes may interfere with
  930. each other, and may access programs, libraries, and other files
  931. available on the system---making it much harder to view them as
  932. @emph{pure} functions.
  933. @node Daemon Offload Setup
  934. @subsection Using the Offload Facility
  935. @cindex offloading
  936. @cindex build hook
  937. When desired, the build daemon can @dfn{offload} derivation builds to
  938. other machines running Guix, using the @code{offload} @dfn{build
  939. hook}@footnote{This feature is available only when
  940. @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
  941. present.}. When that feature is enabled, a list of user-specified build
  942. machines is read from @file{/etc/guix/machines.scm}; every time a build
  943. is requested, for instance via @code{guix build}, the daemon attempts to
  944. offload it to one of the machines that satisfy the constraints of the
  945. derivation, in particular its system types---e.g., @code{x86_64-linux}.
  946. A single machine can have multiple system types, either because its
  947. architecture natively supports it, via emulation
  948. (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
  949. or both. Missing prerequisites for the build are
  950. copied over SSH to the target machine, which then proceeds with the
  951. build; upon success the output(s) of the build are copied back to the
  952. initial machine. The offload facility comes with a basic scheduler that
  953. attempts to select the best machine. The best machine is chosen among
  954. the available machines based on criteria such as:
  955. @enumerate
  956. @item
  957. The availability of a build slot. A build machine can have as many
  958. build slots (connections) as the value of the @code{parallel-builds}
  959. field of its @code{build-machine} object.
  960. @item
  961. Its relative speed, as defined via the @code{speed} field of its
  962. @code{build-machine} object.
  963. @item
  964. Its load. The normalized machine load must be lower than a threshold
  965. value, configurable via the @code{overload-threshold} field of its
  966. @code{build-machine} object.
  967. @item
  968. Disk space availability. More than a 100 MiB must be available.
  969. @end enumerate
  970. The @file{/etc/guix/machines.scm} file typically looks like this:
  971. @lisp
  972. (list (build-machine
  973. (name "eightysix.example.org")
  974. (systems (list "x86_64-linux" "i686-linux"))
  975. (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
  976. (user "bob")
  977. (speed 2.)) ;incredibly fast!
  978. (build-machine
  979. (name "armeight.example.org")
  980. (systems (list "aarch64-linux"))
  981. (host-key "ssh-rsa AAAAB3Nza@dots{}")
  982. (user "alice")
  983. (private-key
  984. (string-append (getenv "HOME")
  985. "/.ssh/identity-for-guix"))))
  986. @end lisp
  987. @noindent
  988. In the example above we specify a list of two build machines, one for
  989. the @code{x86_64} and @code{i686} architectures and one for the
  990. @code{aarch64} architecture.
  991. In fact, this file is---not surprisingly!---a Scheme file that is
  992. evaluated when the @code{offload} hook is started. Its return value
  993. must be a list of @code{build-machine} objects. While this example
  994. shows a fixed list of build machines, one could imagine, say, using
  995. DNS-SD to return a list of potential build machines discovered in the
  996. local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
  997. Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
  998. detailed below.
  999. @deftp {Data Type} build-machine
  1000. This data type represents build machines to which the daemon may offload
  1001. builds. The important fields are:
  1002. @table @code
  1003. @item name
  1004. The host name of the remote machine.
  1005. @item systems
  1006. The system types the remote machine supports---e.g., @code{(list
  1007. "x86_64-linux" "i686-linux")}.
  1008. @item user
  1009. The user account to use when connecting to the remote machine over SSH.
  1010. Note that the SSH key pair must @emph{not} be passphrase-protected, to
  1011. allow non-interactive logins.
  1012. @item host-key
  1013. This must be the machine's SSH @dfn{public host key} in OpenSSH format.
  1014. This is used to authenticate the machine when we connect to it. It is a
  1015. long string that looks like this:
  1016. @example
  1017. ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
  1018. @end example
  1019. If the machine is running the OpenSSH daemon, @command{sshd}, the host
  1020. key can be found in a file such as
  1021. @file{/etc/ssh/ssh_host_ed25519_key.pub}.
  1022. If the machine is running the SSH daemon of GNU@tie{}lsh,
  1023. @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
  1024. similar file. It can be converted to the OpenSSH format using
  1025. @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
  1026. @example
  1027. $ lsh-export-key --openssh < /etc/lsh/host-key.pub
  1028. ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
  1029. @end example
  1030. @end table
  1031. A number of optional fields may be specified:
  1032. @table @asis
  1033. @item @code{port} (default: @code{22})
  1034. Port number of SSH server on the machine.
  1035. @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
  1036. The SSH private key file to use when connecting to the machine, in
  1037. OpenSSH format. This key must not be protected with a passphrase.
  1038. Note that the default value is the private key @emph{of the root
  1039. account}. Make sure it exists if you use the default.
  1040. @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
  1041. @itemx @code{compression-level} (default: @code{3})
  1042. The SSH-level compression methods and compression level requested.
  1043. Note that offloading relies on SSH compression to reduce bandwidth usage
  1044. when transferring files to and from build machines.
  1045. @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
  1046. File name of the Unix-domain socket @command{guix-daemon} is listening
  1047. to on that machine.
  1048. @item @code{overload-threshold} (default: @code{0.6})
  1049. The load threshold above which a potential offload machine is
  1050. disregarded by the offload scheduler. The value roughly translates to
  1051. the total processor usage of the build machine, ranging from 0.0 (0%) to
  1052. 1.0 (100%). It can also be disabled by setting
  1053. @code{overload-threshold} to @code{#f}.
  1054. @item @code{parallel-builds} (default: @code{1})
  1055. The number of builds that may run in parallel on the machine.
  1056. @item @code{speed} (default: @code{1.0})
  1057. A ``relative speed factor''. The offload scheduler will tend to prefer
  1058. machines with a higher speed factor.
  1059. @item @code{features} (default: @code{'()})
  1060. A list of strings denoting specific features supported by the machine.
  1061. An example is @code{"kvm"} for machines that have the KVM Linux modules
  1062. and corresponding hardware support. Derivations can request features by
  1063. name, and they will be scheduled on matching build machines.
  1064. @end table
  1065. @end deftp
  1066. The @command{guix} command must be in the search path on the build
  1067. machines. You can check whether this is the case by running:
  1068. @example
  1069. ssh build-machine guix repl --version
  1070. @end example
  1071. There is one last thing to do once @file{machines.scm} is in place. As
  1072. explained above, when offloading, files are transferred back and forth
  1073. between the machine stores. For this to work, you first need to
  1074. generate a key pair on each machine to allow the daemon to export signed
  1075. archives of files from the store (@pxref{Invoking guix archive}):
  1076. @example
  1077. # guix archive --generate-key
  1078. @end example
  1079. @noindent
  1080. Each build machine must authorize the key of the master machine so that
  1081. it accepts store items it receives from the master:
  1082. @example
  1083. # guix archive --authorize < master-public-key.txt
  1084. @end example
  1085. @noindent
  1086. Likewise, the master machine must authorize the key of each build machine.
  1087. All the fuss with keys is here to express pairwise mutual trust
  1088. relations between the master and the build machines. Concretely, when
  1089. the master receives files from a build machine (and @i{vice versa}), its
  1090. build daemon can make sure they are genuine, have not been tampered
  1091. with, and that they are signed by an authorized key.
  1092. @cindex offload test
  1093. To test whether your setup is operational, run this command on the
  1094. master node:
  1095. @example
  1096. # guix offload test
  1097. @end example
  1098. This will attempt to connect to each of the build machines specified in
  1099. @file{/etc/guix/machines.scm}, make sure Guix is
  1100. available on each machine, attempt to export to the machine and import
  1101. from it, and report any error in the process.
  1102. If you want to test a different machine file, just specify it on the
  1103. command line:
  1104. @example
  1105. # guix offload test machines-qualif.scm
  1106. @end example
  1107. Last, you can test the subset of the machines whose name matches a
  1108. regular expression like this:
  1109. @example
  1110. # guix offload test machines.scm '\.gnu\.org$'
  1111. @end example
  1112. @cindex offload status
  1113. To display the current load of all build hosts, run this command on the
  1114. main node:
  1115. @example
  1116. # guix offload status
  1117. @end example
  1118. @node SELinux Support
  1119. @subsection SELinux Support
  1120. @cindex SELinux, daemon policy
  1121. @cindex mandatory access control, SELinux
  1122. @cindex security, guix-daemon
  1123. Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
  1124. can be installed on a system where SELinux is enabled, in order to label
  1125. Guix files and to specify the expected behavior of the daemon. Since
  1126. Guix System does not provide an SELinux base policy, the daemon policy cannot
  1127. be used on Guix System.
  1128. @subsubsection Installing the SELinux policy
  1129. @cindex SELinux, policy installation
  1130. To install the policy run this command as root:
  1131. @example
  1132. semodule -i etc/guix-daemon.cil
  1133. @end example
  1134. Then relabel the file system with @code{restorecon} or by a different
  1135. mechanism provided by your system.
  1136. Once the policy is installed, the file system has been relabeled, and
  1137. the daemon has been restarted, it should be running in the
  1138. @code{guix_daemon_t} context. You can confirm this with the following
  1139. command:
  1140. @example
  1141. ps -Zax | grep guix-daemon
  1142. @end example
  1143. Monitor the SELinux log files as you run a command like @code{guix build
  1144. hello} to convince yourself that SELinux permits all necessary
  1145. operations.
  1146. @subsubsection Limitations
  1147. @cindex SELinux, limitations
  1148. This policy is not perfect. Here is a list of limitations or quirks
  1149. that should be considered when deploying the provided SELinux policy for
  1150. the Guix daemon.
  1151. @enumerate
  1152. @item
  1153. @code{guix_daemon_socket_t} isn’t actually used. None of the socket
  1154. operations involve contexts that have anything to do with
  1155. @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
  1156. but it would be preferrable to define socket rules for only this label.
  1157. @item
  1158. @code{guix gc} cannot access arbitrary links to profiles. By design,
  1159. the file label of the destination of a symlink is independent of the
  1160. file label of the link itself. Although all profiles under
  1161. $localstatedir are labelled, the links to these profiles inherit the
  1162. label of the directory they are in. For links in the user’s home
  1163. directory this will be @code{user_home_t}. But for links from the root
  1164. user’s home directory, or @file{/tmp}, or the HTTP server’s working
  1165. directory, etc, this won’t work. @code{guix gc} would be prevented from
  1166. reading and following these links.
  1167. @item
  1168. The daemon’s feature to listen for TCP connections might no longer work.
  1169. This might require extra rules, because SELinux treats network sockets
  1170. differently from files.
  1171. @item
  1172. Currently all files with a name matching the regular expression
  1173. @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
  1174. label @code{guix_daemon_exec_t}; this means that @emph{any} file with
  1175. that name in any profile would be permitted to run in the
  1176. @code{guix_daemon_t} domain. This is not ideal. An attacker could
  1177. build a package that provides this executable and convince a user to
  1178. install and run it, which lifts it into the @code{guix_daemon_t} domain.
  1179. At that point SELinux could not prevent it from accessing files that are
  1180. allowed for processes in that domain.
  1181. You will need to relabel the store directory after all upgrades to
  1182. @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
  1183. store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
  1184. or by other means provided by your operating system.
  1185. We could generate a much more restrictive policy at installation time,
  1186. so that only the @emph{exact} file name of the currently installed
  1187. @code{guix-daemon} executable would be labelled with
  1188. @code{guix_daemon_exec_t}, instead of using a broad regular expression.
  1189. The downside is that root would have to install or upgrade the policy at
  1190. installation time whenever the Guix package that provides the
  1191. effectively running @code{guix-daemon} executable is upgraded.
  1192. @end enumerate
  1193. @node Invoking guix-daemon
  1194. @section Invoking @command{guix-daemon}
  1195. The @command{guix-daemon} program implements all the functionality to
  1196. access the store. This includes launching build processes, running the
  1197. garbage collector, querying the availability of a build result, etc. It
  1198. is normally run as @code{root} like this:
  1199. @example
  1200. # guix-daemon --build-users-group=guixbuild
  1201. @end example
  1202. @noindent
  1203. For details on how to set it up, @pxref{Setting Up the Daemon}.
  1204. @cindex chroot
  1205. @cindex container, build environment
  1206. @cindex build environment
  1207. @cindex reproducible builds
  1208. By default, @command{guix-daemon} launches build processes under
  1209. different UIDs, taken from the build group specified with
  1210. @option{--build-users-group}. In addition, each build process is run in a
  1211. chroot environment that only contains the subset of the store that the
  1212. build process depends on, as specified by its derivation
  1213. (@pxref{Programming Interface, derivation}), plus a set of specific
  1214. system directories. By default, the latter contains @file{/dev} and
  1215. @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
  1216. @dfn{container}: in addition to having its own file system tree, it has
  1217. a separate mount name space, its own PID name space, network name space,
  1218. etc. This helps achieve reproducible builds (@pxref{Features}).
  1219. When the daemon performs a build on behalf of the user, it creates a
  1220. build directory under @file{/tmp} or under the directory specified by
  1221. its @env{TMPDIR} environment variable. This directory is shared with
  1222. the container for the duration of the build, though within the container,
  1223. the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
  1224. The build directory is automatically deleted upon completion, unless the
  1225. build failed and the client specified @option{--keep-failed}
  1226. (@pxref{Common Build Options, @option{--keep-failed}}).
  1227. The daemon listens for connections and spawns one sub-process for each session
  1228. started by a client (one of the @command{guix} sub-commands). The
  1229. @command{guix processes} command allows you to get an overview of the activity
  1230. on your system by viewing each of the active sessions and clients.
  1231. @xref{Invoking guix processes}, for more information.
  1232. The following command-line options are supported:
  1233. @table @code
  1234. @item --build-users-group=@var{group}
  1235. Take users from @var{group} to run build processes (@pxref{Setting Up
  1236. the Daemon, build users}).
  1237. @item --no-substitutes
  1238. @cindex substitutes
  1239. Do not use substitutes for build products. That is, always build things
  1240. locally instead of allowing downloads of pre-built binaries
  1241. (@pxref{Substitutes}).
  1242. When the daemon runs with @option{--no-substitutes}, clients can still
  1243. explicitly enable substitution @i{via} the @code{set-build-options}
  1244. remote procedure call (@pxref{The Store}).
  1245. @anchor{daemon-substitute-urls}
  1246. @item --substitute-urls=@var{urls}
  1247. Consider @var{urls} the default whitespace-separated list of substitute
  1248. source URLs. When this option is omitted,
  1249. @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
  1250. This means that substitutes may be downloaded from @var{urls}, as long
  1251. as they are signed by a trusted signature (@pxref{Substitutes}).
  1252. @xref{Getting Substitutes from Other Servers}, for more information on
  1253. how to configure the daemon to get substitutes from other servers.
  1254. @cindex offloading
  1255. @item --no-offload
  1256. Do not use offload builds to other machines (@pxref{Daemon Offload
  1257. Setup}). That is, always build things locally instead of offloading
  1258. builds to remote machines.
  1259. @item --cache-failures
  1260. Cache build failures. By default, only successful builds are cached.
  1261. When this option is used, @command{guix gc --list-failures} can be used
  1262. to query the set of store items marked as failed; @command{guix gc
  1263. --clear-failures} removes store items from the set of cached failures.
  1264. @xref{Invoking guix gc}.
  1265. @item --cores=@var{n}
  1266. @itemx -c @var{n}
  1267. Use @var{n} CPU cores to build each derivation; @code{0} means as many
  1268. as available.
  1269. The default value is @code{0}, but it may be overridden by clients, such
  1270. as the @option{--cores} option of @command{guix build} (@pxref{Invoking
  1271. guix build}).
  1272. The effect is to define the @env{NIX_BUILD_CORES} environment variable
  1273. in the build process, which can then use it to exploit internal
  1274. parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
  1275. @item --max-jobs=@var{n}
  1276. @itemx -M @var{n}
  1277. Allow at most @var{n} build jobs in parallel. The default value is
  1278. @code{1}. Setting it to @code{0} means that no builds will be performed
  1279. locally; instead, the daemon will offload builds (@pxref{Daemon Offload
  1280. Setup}), or simply fail.
  1281. @item --max-silent-time=@var{seconds}
  1282. When the build or substitution process remains silent for more than
  1283. @var{seconds}, terminate it and report a build failure.
  1284. The default value is @code{0}, which disables the timeout.
  1285. The value specified here can be overridden by clients (@pxref{Common
  1286. Build Options, @option{--max-silent-time}}).
  1287. @item --timeout=@var{seconds}
  1288. Likewise, when the build or substitution process lasts for more than
  1289. @var{seconds}, terminate it and report a build failure.
  1290. The default value is @code{0}, which disables the timeout.
  1291. The value specified here can be overridden by clients (@pxref{Common
  1292. Build Options, @option{--timeout}}).
  1293. @item --rounds=@var{N}
  1294. Build each derivation @var{n} times in a row, and raise an error if
  1295. consecutive build results are not bit-for-bit identical. Note that this
  1296. setting can be overridden by clients such as @command{guix build}
  1297. (@pxref{Invoking guix build}).
  1298. When used in conjunction with @option{--keep-failed}, the differing
  1299. output is kept in the store, under @file{/gnu/store/@dots{}-check}.
  1300. This makes it easy to look for differences between the two results.
  1301. @item --debug
  1302. Produce debugging output.
  1303. This is useful to debug daemon start-up issues, but then it may be
  1304. overridden by clients, for example the @option{--verbosity} option of
  1305. @command{guix build} (@pxref{Invoking guix build}).
  1306. @item --chroot-directory=@var{dir}
  1307. Add @var{dir} to the build chroot.
  1308. Doing this may change the result of build processes---for instance if
  1309. they use optional dependencies found in @var{dir} when it is available,
  1310. and not otherwise. For that reason, it is not recommended to do so.
  1311. Instead, make sure that each derivation declares all the inputs that it
  1312. needs.
  1313. @item --disable-chroot
  1314. Disable chroot builds.
  1315. Using this option is not recommended since, again, it would allow build
  1316. processes to gain access to undeclared dependencies. It is necessary,
  1317. though, when @command{guix-daemon} is running under an unprivileged user
  1318. account.
  1319. @item --log-compression=@var{type}
  1320. Compress build logs according to @var{type}, one of @code{gzip},
  1321. @code{bzip2}, or @code{none}.
  1322. Unless @option{--lose-logs} is used, all the build logs are kept in the
  1323. @var{localstatedir}. To save space, the daemon automatically compresses
  1324. them with Bzip2 by default.
  1325. @item --discover[=yes|no]
  1326. Whether to discover substitute servers on the local network using mDNS
  1327. and DNS-SD.
  1328. This feature is still experimental. However, here are a few
  1329. considerations.
  1330. @enumerate
  1331. @item
  1332. It might be faster/less expensive than fetching from remote servers;
  1333. @item
  1334. There are no security risks, only genuine substitutes will be used
  1335. (@pxref{Substitute Authentication});
  1336. @item
  1337. An attacker advertising @command{guix publish} on your LAN cannot serve
  1338. you malicious binaries, but they can learn what software you’re
  1339. installing;
  1340. @item
  1341. Servers may serve substitute over HTTP, unencrypted, so anyone on the
  1342. LAN can see what software you’re installing.
  1343. @end enumerate
  1344. It is also possible to enable or disable substitute server discovery at
  1345. run-time by running:
  1346. @example
  1347. herd discover guix-daemon on
  1348. herd discover guix-daemon off
  1349. @end example
  1350. @item --disable-deduplication
  1351. @cindex deduplication
  1352. Disable automatic file ``deduplication'' in the store.
  1353. By default, files added to the store are automatically ``deduplicated'':
  1354. if a newly added file is identical to another one found in the store,
  1355. the daemon makes the new file a hard link to the other file. This can
  1356. noticeably reduce disk usage, at the expense of slightly increased
  1357. input/output load at the end of a build process. This option disables
  1358. this optimization.
  1359. @item --gc-keep-outputs[=yes|no]
  1360. Tell whether the garbage collector (GC) must keep outputs of live
  1361. derivations.
  1362. @cindex GC roots
  1363. @cindex garbage collector roots
  1364. When set to @code{yes}, the GC will keep the outputs of any live
  1365. derivation available in the store---the @file{.drv} files. The default
  1366. is @code{no}, meaning that derivation outputs are kept only if they are
  1367. reachable from a GC root. @xref{Invoking guix gc}, for more on GC
  1368. roots.
  1369. @item --gc-keep-derivations[=yes|no]
  1370. Tell whether the garbage collector (GC) must keep derivations
  1371. corresponding to live outputs.
  1372. When set to @code{yes}, as is the case by default, the GC keeps
  1373. derivations---i.e., @file{.drv} files---as long as at least one of their
  1374. outputs is live. This allows users to keep track of the origins of
  1375. items in their store. Setting it to @code{no} saves a bit of disk
  1376. space.
  1377. In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
  1378. liveness to flow from outputs to derivations, and setting
  1379. @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
  1380. derivations to outputs. When both are set to @code{yes}, the effect is
  1381. to keep all the build prerequisites (the sources, compiler, libraries,
  1382. and other build-time tools) of live objects in the store, regardless of
  1383. whether these prerequisites are reachable from a GC root. This is
  1384. convenient for developers since it saves rebuilds or downloads.
  1385. @item --impersonate-linux-2.6
  1386. On Linux-based systems, impersonate Linux 2.6. This means that the
  1387. kernel's @command{uname} system call will report 2.6 as the release number.
  1388. This might be helpful to build programs that (usually wrongfully) depend
  1389. on the kernel version number.
  1390. @item --lose-logs
  1391. Do not keep build logs. By default they are kept under
  1392. @file{@var{localstatedir}/guix/log}.
  1393. @item --system=@var{system}
  1394. Assume @var{system} as the current system type. By default it is the
  1395. architecture/kernel pair found at configure time, such as
  1396. @code{x86_64-linux}.
  1397. @item --listen=@var{endpoint}
  1398. Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
  1399. as the file name of a Unix-domain socket if it starts with
  1400. @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
  1401. host name or host name and port to listen to. Here are a few examples:
  1402. @table @code
  1403. @item --listen=/gnu/var/daemon
  1404. Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
  1405. creating it if needed.
  1406. @item --listen=localhost
  1407. @cindex daemon, remote access
  1408. @cindex remote access to the daemon
  1409. @cindex daemon, cluster setup
  1410. @cindex clusters, daemon setup
  1411. Listen for TCP connections on the network interface corresponding to
  1412. @code{localhost}, on port 44146.
  1413. @item --listen=128.0.0.42:1234
  1414. Listen for TCP connections on the network interface corresponding to
  1415. @code{128.0.0.42}, on port 1234.
  1416. @end table
  1417. This option can be repeated multiple times, in which case
  1418. @command{guix-daemon} accepts connections on all the specified
  1419. endpoints. Users can tell client commands what endpoint to connect to
  1420. by setting the @env{GUIX_DAEMON_SOCKET} environment variable
  1421. (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
  1422. @quotation Note
  1423. The daemon protocol is @emph{unauthenticated and unencrypted}. Using
  1424. @option{--listen=@var{host}} is suitable on local networks, such as
  1425. clusters, where only trusted nodes may connect to the build daemon. In
  1426. other cases where remote access to the daemon is needed, we recommend
  1427. using Unix-domain sockets along with SSH.
  1428. @end quotation
  1429. When @option{--listen} is omitted, @command{guix-daemon} listens for
  1430. connections on the Unix-domain socket located at
  1431. @file{@var{localstatedir}/guix/daemon-socket/socket}.
  1432. @end table
  1433. @node Application Setup
  1434. @section Application Setup
  1435. @cindex foreign distro
  1436. When using Guix on top of GNU/Linux distribution other than Guix System---a
  1437. so-called @dfn{foreign distro}---a few additional steps are needed to
  1438. get everything in place. Here are some of them.
  1439. @subsection Locales
  1440. @anchor{locales-and-locpath}
  1441. @cindex locales, when not on Guix System
  1442. @vindex LOCPATH
  1443. @vindex GUIX_LOCPATH
  1444. Packages installed @i{via} Guix will not use the locale data of the
  1445. host system. Instead, you must first install one of the locale packages
  1446. available with Guix and then define the @env{GUIX_LOCPATH} environment
  1447. variable:
  1448. @example
  1449. $ guix install glibc-locales
  1450. $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
  1451. @end example
  1452. Note that the @code{glibc-locales} package contains data for all the
  1453. locales supported by the GNU@tie{}libc and weighs in at around
  1454. 917@tie{}MiB@. Alternatively, the @code{glibc-utf8-locales} is smaller but
  1455. limited to a few UTF-8 locales.
  1456. The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
  1457. (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
  1458. Manual}). There are two important differences though:
  1459. @enumerate
  1460. @item
  1461. @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
  1462. provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
  1463. to make sure the programs of the foreign distro will not end up loading
  1464. incompatible locale data.
  1465. @item
  1466. libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
  1467. @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
  1468. should your Guix profile contain a mixture of programs linked against
  1469. different libc version, each libc version will only try to load locale
  1470. data in the right format.
  1471. @end enumerate
  1472. This is important because the locale data format used by different libc
  1473. versions may be incompatible.
  1474. @subsection Name Service Switch
  1475. @cindex name service switch, glibc
  1476. @cindex NSS (name service switch), glibc
  1477. @cindex nscd (name service caching daemon)
  1478. @cindex name service caching daemon (nscd)
  1479. When using Guix on a foreign distro, we @emph{strongly recommend} that
  1480. the system run the GNU C library's @dfn{name service cache daemon},
  1481. @command{nscd}, which should be listening on the
  1482. @file{/var/run/nscd/socket} socket. Failing to do that, applications
  1483. installed with Guix may fail to look up host names or user accounts, or
  1484. may even crash. The next paragraphs explain why.
  1485. @cindex @file{nsswitch.conf}
  1486. The GNU C library implements a @dfn{name service switch} (NSS), which is
  1487. an extensible mechanism for ``name lookups'' in general: host name
  1488. resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
  1489. The GNU C Library Reference Manual}).
  1490. @cindex Network information service (NIS)
  1491. @cindex NIS (Network information service)
  1492. Being extensible, the NSS supports @dfn{plugins}, which provide new name
  1493. lookup implementations: for example, the @code{nss-mdns} plugin allow
  1494. resolution of @code{.local} host names, the @code{nis} plugin allows
  1495. user account lookup using the Network information service (NIS), and so
  1496. on. These extra ``lookup services'' are configured system-wide in
  1497. @file{/etc/nsswitch.conf}, and all the programs running on the system
  1498. honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
  1499. Reference Manual}).
  1500. When they perform a name lookup---for instance by calling the
  1501. @code{getaddrinfo} function in C---applications first try to connect to
  1502. the nscd; on success, nscd performs name lookups on their behalf. If
  1503. the nscd is not running, then they perform the name lookup by
  1504. themselves, by loading the name lookup services into their own address
  1505. space and running it. These name lookup services---the
  1506. @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
  1507. the host system's C library, rather than from the C library the
  1508. application is linked against (the C library coming from Guix).
  1509. And this is where the problem is: if your application is linked against
  1510. Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
  1511. another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
  1512. likely crash or have its name lookups fail unexpectedly.
  1513. Running @command{nscd} on the system, among other advantages, eliminates
  1514. this binary incompatibility problem because those @code{libnss_*.so}
  1515. files are loaded in the @command{nscd} process, not in applications
  1516. themselves.
  1517. @subsection X11 Fonts
  1518. @cindex fonts
  1519. The majority of graphical applications use Fontconfig to locate and
  1520. load fonts and perform X11-client-side rendering. The @code{fontconfig}
  1521. package in Guix looks for fonts in @file{$HOME/.guix-profile}
  1522. by default. Thus, to allow graphical applications installed with Guix
  1523. to display fonts, you have to install fonts with Guix as well.
  1524. Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
  1525. @code{font-gnu-freefont}.
  1526. @cindex @code{fc-cache}
  1527. @cindex font cache
  1528. Once you have installed or removed fonts, or when you notice an
  1529. application that does not find fonts, you may need to install Fontconfig
  1530. and to force an update of its font cache by running:
  1531. @example
  1532. guix install fontconfig
  1533. fc-cache -rv
  1534. @end example
  1535. To display text written in Chinese languages, Japanese, or Korean in
  1536. graphical applications, consider installing
  1537. @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
  1538. has multiple outputs, one per language family (@pxref{Packages with
  1539. Multiple Outputs}). For instance, the following command installs fonts
  1540. for Chinese languages:
  1541. @example
  1542. guix install font-adobe-source-han-sans:cn
  1543. @end example
  1544. @cindex @code{xterm}
  1545. Older programs such as @command{xterm} do not use Fontconfig and instead
  1546. rely on server-side font rendering. Such programs require to specify a
  1547. full name of a font using XLFD (X Logical Font Description), like this:
  1548. @example
  1549. -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
  1550. @end example
  1551. To be able to use such full names for the TrueType fonts installed in
  1552. your Guix profile, you need to extend the font path of the X server:
  1553. @c Note: 'xset' does not accept symlinks so the trick below arranges to
  1554. @c get at the real directory. See <https://bugs.gnu.org/30655>.
  1555. @example
  1556. xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
  1557. @end example
  1558. @cindex @code{xlsfonts}
  1559. After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
  1560. to make sure your TrueType fonts are listed there.
  1561. @subsection X.509 Certificates
  1562. @cindex @code{nss-certs}
  1563. The @code{nss-certs} package provides X.509 certificates, which allow
  1564. programs to authenticate Web servers accessed over HTTPS.
  1565. When using Guix on a foreign distro, you can install this package and
  1566. define the relevant environment variables so that packages know where to
  1567. look for certificates. @xref{X.509 Certificates}, for detailed
  1568. information.
  1569. @subsection Emacs Packages
  1570. @cindex @code{emacs}
  1571. When you install Emacs packages with Guix, the Elisp files are placed
  1572. under the @file{share/emacs/site-lisp/} directory of the profile in
  1573. which they are installed. The Elisp libraries are made available to
  1574. Emacs through the @env{EMACSLOADPATH} environment variable, which is
  1575. set when installing Emacs itself.
  1576. Additionally, autoload definitions are automatically evaluated at the
  1577. initialization of Emacs, by the Guix-specific
  1578. @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
  1579. want to avoid auto-loading the Emacs packages installed with Guix, you
  1580. can do so by running Emacs with the @option{--no-site-file} option
  1581. (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
  1582. @node Upgrading Guix
  1583. @section Upgrading Guix
  1584. @cindex Upgrading Guix, on a foreign distro
  1585. To upgrade Guix, run:
  1586. @example
  1587. guix pull
  1588. @end example
  1589. @xref{Invoking guix pull}, for more information.
  1590. @cindex upgrading Guix for the root user, on a foreign distro
  1591. @cindex upgrading the Guix daemon, on a foreign distro
  1592. @cindex @command{guix pull} for the root user, on a foreign distro
  1593. On a foreign distro, you can upgrade the build daemon by running:
  1594. @example
  1595. sudo -i guix pull
  1596. @end example
  1597. @noindent
  1598. followed by (assuming your distro uses the systemd service management
  1599. tool):
  1600. @example
  1601. systemctl restart guix-daemon.service
  1602. @end example
  1603. On Guix System, upgrading the daemon is achieved by reconfiguring the
  1604. system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
  1605. @c TODO What else?
  1606. @c *********************************************************************
  1607. @node System Installation
  1608. @chapter System Installation
  1609. @cindex installing Guix System
  1610. @cindex Guix System, installation
  1611. This section explains how to install Guix System
  1612. on a machine. Guix, as a package manager, can
  1613. also be installed on top of a running GNU/Linux system,
  1614. @pxref{Installation}.
  1615. @ifinfo
  1616. @quotation Note
  1617. @c This paragraph is for people reading this from tty2 of the
  1618. @c installation image.
  1619. You are reading this documentation with an Info reader. For details on
  1620. how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
  1621. link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
  1622. Info}. Hit @kbd{l} afterwards to come back here.
  1623. Alternatively, run @command{info info} in another tty to keep the manual
  1624. available.
  1625. @end quotation
  1626. @end ifinfo
  1627. @menu
  1628. * Limitations:: What you can expect.
  1629. * Hardware Considerations:: Supported hardware.
  1630. * USB Stick and DVD Installation:: Preparing the installation medium.
  1631. * Preparing for Installation:: Networking, partitioning, etc.
  1632. * Guided Graphical Installation:: Easy graphical installation.
  1633. * Manual Installation:: Manual installation for wizards.
  1634. * After System Installation:: When installation succeeded.
  1635. * Installing Guix in a VM:: Guix System playground.
  1636. * Building the Installation Image:: How this comes to be.
  1637. @end menu
  1638. @node Limitations
  1639. @section Limitations
  1640. We consider Guix System to be ready for a wide range of ``desktop'' and server
  1641. use cases. The reliability guarantees it provides---transactional upgrades
  1642. and rollbacks, reproducibility---make it a solid foundation.
  1643. Nevertheless, before you proceed with the installation, be aware of the
  1644. following noteworthy limitations applicable to version @value{VERSION}:
  1645. @itemize
  1646. @item
  1647. More and more system services are provided (@pxref{Services}), but some
  1648. may be missing.
  1649. @item
  1650. GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
  1651. as well as a number of X11 window managers. However, KDE is currently
  1652. missing.
  1653. @end itemize
  1654. More than a disclaimer, this is an invitation to report issues (and success
  1655. stories!), and to join us in improving it. @xref{Contributing}, for more
  1656. info.
  1657. @node Hardware Considerations
  1658. @section Hardware Considerations
  1659. @cindex hardware support on Guix System
  1660. GNU@tie{}Guix focuses on respecting the user's computing freedom. It
  1661. builds around the kernel Linux-libre, which means that only hardware for
  1662. which free software drivers and firmware exist is supported. Nowadays,
  1663. a wide range of off-the-shelf hardware is supported on
  1664. GNU/Linux-libre---from keyboards to graphics cards to scanners and
  1665. Ethernet controllers. Unfortunately, there are still areas where
  1666. hardware vendors deny users control over their own computing, and such
  1667. hardware is not supported on Guix System.
  1668. @cindex WiFi, hardware support
  1669. One of the main areas where free drivers or firmware are lacking is WiFi
  1670. devices. WiFi devices known to work include those using Atheros chips
  1671. (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
  1672. driver, and those using Broadcom/AirForce chips (BCM43xx with
  1673. Wireless-Core Revision 5), which corresponds to the @code{b43-open}
  1674. Linux-libre driver. Free firmware exists for both and is available
  1675. out-of-the-box on Guix System, as part of @code{%base-firmware}
  1676. (@pxref{operating-system Reference, @code{firmware}}).
  1677. @cindex RYF, Respects Your Freedom
  1678. The @uref{https://www.fsf.org/, Free Software Foundation} runs
  1679. @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
  1680. certification program for hardware products that respect your freedom
  1681. and your privacy and ensure that you have control over your device. We
  1682. encourage you to check the list of RYF-certified devices.
  1683. Another useful resource is the @uref{https://www.h-node.org/, H-Node}
  1684. web site. It contains a catalog of hardware devices with information
  1685. about their support in GNU/Linux.
  1686. @node USB Stick and DVD Installation
  1687. @section USB Stick and DVD Installation
  1688. An ISO-9660 installation image that can be written to a USB stick or
  1689. burnt to a DVD can be downloaded from
  1690. @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
  1691. where you can replace @code{x86_64-linux} with one of:
  1692. @table @code
  1693. @item x86_64-linux
  1694. for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
  1695. @item i686-linux
  1696. for a 32-bit GNU/Linux system on Intel-compatible CPUs.
  1697. @end table
  1698. @c start duplication of authentication part from ``Binary Installation''
  1699. Make sure to download the associated @file{.sig} file and to verify the
  1700. authenticity of the image against it, along these lines:
  1701. @example
  1702. $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
  1703. $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
  1704. @end example
  1705. If that command fails because you do not have the required public key,
  1706. then run this command to import it:
  1707. @example
  1708. $ wget @value{OPENPGP-SIGNING-KEY-URL} \
  1709. -qO - | gpg --import -
  1710. @end example
  1711. @noindent
  1712. and rerun the @code{gpg --verify} command.
  1713. Take note that a warning like ``This key is not certified with a trusted
  1714. signature!'' is normal.
  1715. @c end duplication
  1716. This image contains the tools necessary for an installation.
  1717. It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
  1718. @unnumberedsubsec Copying to a USB Stick
  1719. To copy the image to a USB stick, follow these steps:
  1720. @enumerate
  1721. @item
  1722. Decompress the image using the @command{xz} command:
  1723. @example
  1724. xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
  1725. @end example
  1726. @item
  1727. Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
  1728. its device name. Assuming that the USB stick is known as @file{/dev/sdX},
  1729. copy the image with:
  1730. @example
  1731. dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
  1732. sync
  1733. @end example
  1734. Access to @file{/dev/sdX} usually requires root privileges.
  1735. @end enumerate
  1736. @unnumberedsubsec Burning on a DVD
  1737. To copy the image to a DVD, follow these steps:
  1738. @enumerate
  1739. @item
  1740. Decompress the image using the @command{xz} command:
  1741. @example
  1742. xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
  1743. @end example
  1744. @item
  1745. Insert a blank DVD into your machine, and determine
  1746. its device name. Assuming that the DVD drive is known as @file{/dev/srX},
  1747. copy the image with:
  1748. @example
  1749. growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
  1750. @end example
  1751. Access to @file{/dev/srX} usually requires root privileges.
  1752. @end enumerate
  1753. @unnumberedsubsec Booting
  1754. Once this is done, you should be able to reboot the system and boot from
  1755. the USB stick or DVD@. The latter usually requires you to get in the
  1756. BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
  1757. In order to boot from Libreboot, switch to the command mode by pressing
  1758. the @kbd{c} key and type @command{search_grub usb}.
  1759. @xref{Installing Guix in a VM}, if, instead, you would like to install
  1760. Guix System in a virtual machine (VM).
  1761. @node Preparing for Installation
  1762. @section Preparing for Installation
  1763. Once you have booted, you can use the guided graphical installer, which makes
  1764. it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
  1765. if you are already familiar with GNU/Linux and if you want more control than
  1766. what the graphical installer provides, you can choose the ``manual''
  1767. installation process (@pxref{Manual Installation}).
  1768. The graphical installer is available on TTY1. You can obtain root shells on
  1769. TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
  1770. this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
  1771. is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
  1772. Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
  1773. which allows you to select text with the left mouse button and to paste it
  1774. with the middle button.
  1775. @quotation Note
  1776. Installation requires access to the Internet so that any missing
  1777. dependencies of your system configuration can be downloaded. See the
  1778. ``Networking'' section below.
  1779. @end quotation
  1780. @node Guided Graphical Installation
  1781. @section Guided Graphical Installation
  1782. The graphical installer is a text-based user interface. It will guide you,
  1783. with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
  1784. The first dialog boxes allow you to set up the system as you use it during the
  1785. installation: you can choose the language, keyboard layout, and set up
  1786. networking, which will be used during the installation. The image below shows
  1787. the networking dialog.
  1788. @image{images/installer-network,5in,, networking setup with the graphical installer}
  1789. Later steps allow you to partition your hard disk, as shown in the image
  1790. below, to choose whether or not to use encrypted file systems, to enter the
  1791. host name and root password, and to create an additional account, among other
  1792. things.
  1793. @image{images/installer-partitions,5in,, partitioning with the graphical installer}
  1794. Note that, at any time, the installer allows you to exit the current
  1795. installation step and resume at a previous step, as show in the image below.
  1796. @image{images/installer-resume,5in,, resuming the installation process}
  1797. Once you're done, the installer produces an operating system configuration and
  1798. displays it (@pxref{Using the Configuration System}). At that point you can
  1799. hit ``OK'' and installation will proceed. On success, you can reboot into the
  1800. new system and enjoy. @xref{After System Installation}, for what's next!
  1801. @node Manual Installation
  1802. @section Manual Installation
  1803. This section describes how you would ``manually'' install GNU@tie{}Guix System
  1804. on your machine. This option requires familiarity with GNU/Linux, with the
  1805. shell, and with common administration tools. If you think this is not for
  1806. you, consider using the guided graphical installer (@pxref{Guided Graphical
  1807. Installation}).
  1808. The installation system provides root shells on TTYs 3 to 6; press
  1809. @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
  1810. many common tools needed to install the system. But it is also a full-blown
  1811. Guix System, which means that you can install additional packages, should you
  1812. need it, using @command{guix package} (@pxref{Invoking guix package}).
  1813. @menu
  1814. * Keyboard Layout and Networking and Partitioning:: Initial setup.
  1815. * Proceeding with the Installation:: Installing.
  1816. @end menu
  1817. @node Keyboard Layout and Networking and Partitioning
  1818. @subsection Keyboard Layout, Networking, and Partitioning
  1819. Before you can install the system, you may want to adjust the keyboard layout,
  1820. set up networking, and partition your target hard disk. This section will
  1821. guide you through this.
  1822. @subsubsection Keyboard Layout
  1823. @cindex keyboard layout
  1824. The installation image uses the US qwerty keyboard layout. If you want
  1825. to change it, you can use the @command{loadkeys} command. For example,
  1826. the following command selects the Dvorak keyboard layout:
  1827. @example
  1828. loadkeys dvorak
  1829. @end example
  1830. See the files under @file{/run/current-system/profile/share/keymaps} for
  1831. a list of available keyboard layouts. Run @command{man loadkeys} for
  1832. more information.
  1833. @subsubsection Networking
  1834. Run the following command to see what your network interfaces are called:
  1835. @example
  1836. ifconfig -a
  1837. @end example
  1838. @noindent
  1839. @dots{} or, using the GNU/Linux-specific @command{ip} command:
  1840. @example
  1841. ip address
  1842. @end example
  1843. @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
  1844. Wired interfaces have a name starting with @samp{e}; for example, the
  1845. interface corresponding to the first on-board Ethernet controller is
  1846. called @samp{eno1}. Wireless interfaces have a name starting with
  1847. @samp{w}, like @samp{w1p2s0}.
  1848. @table @asis
  1849. @item Wired connection
  1850. To configure a wired network run the following command, substituting
  1851. @var{interface} with the name of the wired interface you want to use.
  1852. @example
  1853. ifconfig @var{interface} up
  1854. @end example
  1855. @noindent
  1856. @dots{} or, using the GNU/Linux-specific @command{ip} command:
  1857. @example
  1858. ip link set @var{interface} up
  1859. @end example
  1860. @item Wireless connection
  1861. @cindex wireless
  1862. @cindex WiFi
  1863. To configure wireless networking, you can create a configuration file
  1864. for the @command{wpa_supplicant} configuration tool (its location is not
  1865. important) using one of the available text editors such as
  1866. @command{nano}:
  1867. @example
  1868. nano wpa_supplicant.conf
  1869. @end example
  1870. As an example, the following stanza can go to this file and will work
  1871. for many wireless networks, provided you give the actual SSID and
  1872. passphrase for the network you are connecting to:
  1873. @example
  1874. network=@{
  1875. ssid="@var{my-ssid}"
  1876. key_mgmt=WPA-PSK
  1877. psk="the network's secret passphrase"
  1878. @}
  1879. @end example
  1880. Start the wireless service and run it in the background with the
  1881. following command (substitute @var{interface} with the name of the
  1882. network interface you want to use):
  1883. @example
  1884. wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
  1885. @end example
  1886. Run @command{man wpa_supplicant} for more information.
  1887. @end table
  1888. @cindex DHCP
  1889. At this point, you need to acquire an IP address. On a network where IP
  1890. addresses are automatically assigned @i{via} DHCP, you can run:
  1891. @example
  1892. dhclient -v @var{interface}
  1893. @end example
  1894. Try to ping a server to see if networking is up and running:
  1895. @example
  1896. ping -c 3 gnu.org
  1897. @end example
  1898. Setting up network access is almost always a requirement because the
  1899. image does not contain all the software and tools that may be needed.
  1900. @cindex proxy, during system installation
  1901. If you need HTTP and HTTPS access to go through a proxy, run the
  1902. following command:
  1903. @example
  1904. herd set-http-proxy guix-daemon @var{URL}
  1905. @end example
  1906. @noindent
  1907. where @var{URL} is the proxy URL, for example
  1908. @code{http://example.org:8118}.
  1909. @cindex installing over SSH
  1910. If you want to, you can continue the installation remotely by starting
  1911. an SSH server:
  1912. @example
  1913. herd start ssh-daemon
  1914. @end example
  1915. Make sure to either set a password with @command{passwd}, or configure
  1916. OpenSSH public key authentication before logging in.
  1917. @subsubsection Disk Partitioning
  1918. Unless this has already been done, the next step is to partition, and
  1919. then format the target partition(s).
  1920. The installation image includes several partitioning tools, including
  1921. Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
  1922. @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
  1923. the partition layout you want:
  1924. @example
  1925. cfdisk
  1926. @end example
  1927. If your disk uses the GUID Partition Table (GPT) format and you plan to
  1928. install BIOS-based GRUB (which is the default), make sure a BIOS Boot
  1929. Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
  1930. manual}).
  1931. @cindex EFI, installation
  1932. @cindex UEFI, installation
  1933. @cindex ESP, EFI system partition
  1934. If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
  1935. (ESP) is required. This partition can be mounted at @file{/boot/efi} for
  1936. instance and must have the @code{esp} flag set. E.g., for @command{parted}:
  1937. @example
  1938. parted /dev/sda set 1 esp on
  1939. @end example
  1940. @quotation Note
  1941. @vindex grub-bootloader
  1942. @vindex grub-efi-bootloader
  1943. Unsure whether to use EFI- or BIOS-based GRUB? If the directory
  1944. @file{/sys/firmware/efi} exists in the installation image, then you should
  1945. probably perform an EFI installation, using @code{grub-efi-bootloader}.
  1946. Otherwise you should use the BIOS-based GRUB, known as
  1947. @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
  1948. bootloaders.
  1949. @end quotation
  1950. Once you are done partitioning the target hard disk drive, you have to
  1951. create a file system on the relevant partition(s)@footnote{Currently
  1952. Guix System only supports ext4, btrfs, JFS, and F2FS file systems. In
  1953. particular, code that reads file system UUIDs and labels only works for these
  1954. file system types.}. For the ESP, if you have one and assuming it is
  1955. @file{/dev/sda1}, run:
  1956. @example
  1957. mkfs.fat -F32 /dev/sda1
  1958. @end example
  1959. For the root file system, ext4 is the most widely used format. Other
  1960. file systems, such as Btrfs, support compression, which is reported to
  1961. nicely complement file deduplication that the daemon performs
  1962. independently of the file system (@pxref{Invoking guix-daemon,
  1963. deduplication}).
  1964. Preferably, assign file systems a label so that you can easily and
  1965. reliably refer to them in @code{file-system} declarations (@pxref{File
  1966. Systems}). This is typically done using the @code{-L} option of
  1967. @command{mkfs.ext4} and related commands. So, assuming the target root
  1968. partition lives at @file{/dev/sda2}, a file system with the label
  1969. @code{my-root} can be created with:
  1970. @example
  1971. mkfs.ext4 -L my-root /dev/sda2
  1972. @end example
  1973. @cindex encrypted disk
  1974. If you are instead planning to encrypt the root partition, you can use
  1975. the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
  1976. @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
  1977. @code{man cryptsetup}} for more information). Assuming you want to
  1978. store the root partition on @file{/dev/sda2}, the command sequence would
  1979. be along these lines:
  1980. @example
  1981. cryptsetup luksFormat /dev/sda2
  1982. cryptsetup open --type luks /dev/sda2 my-partition
  1983. mkfs.ext4 -L my-root /dev/mapper/my-partition
  1984. @end example
  1985. Once that is done, mount the target file system under @file{/mnt}
  1986. with a command like (again, assuming @code{my-root} is the label of the
  1987. root file system):
  1988. @example
  1989. mount LABEL=my-root /mnt
  1990. @end example
  1991. Also mount any other file systems you would like to use on the target
  1992. system relative to this path. If you have opted for @file{/boot/efi} as an
  1993. EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
  1994. found by @code{guix system init} afterwards.
  1995. Finally, if you plan to use one or more swap partitions (@pxref{Memory
  1996. Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
  1997. sure to initialize them with @command{mkswap}. Assuming you have one
  1998. swap partition on @file{/dev/sda3}, you would run:
  1999. @example
  2000. mkswap /dev/sda3
  2001. swapon /dev/sda3
  2002. @end example
  2003. Alternatively, you may use a swap file. For example, assuming that in
  2004. the new system you want to use the file @file{/swapfile} as a swap file,
  2005. you would run@footnote{This example will work for many types of file
  2006. systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
  2007. btrfs), the required steps may be different. For details, see the
  2008. manual pages for @command{mkswap} and @command{swapon}.}:
  2009. @example
  2010. # This is 10 GiB of swap space. Adjust "count" to change the size.
  2011. dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
  2012. # For security, make the file readable and writable only by root.
  2013. chmod 600 /mnt/swapfile
  2014. mkswap /mnt/swapfile
  2015. swapon /mnt/swapfile
  2016. @end example
  2017. Note that if you have encrypted the root partition and created a swap
  2018. file in its file system as described above, then the encryption also
  2019. protects the swap file, just like any other file in that file system.
  2020. @node Proceeding with the Installation
  2021. @subsection Proceeding with the Installation
  2022. With the target partitions ready and the target root mounted on
  2023. @file{/mnt}, we're ready to go. First, run:
  2024. @example
  2025. herd start cow-store /mnt
  2026. @end example
  2027. This makes @file{/gnu/store} copy-on-write, such that packages added to it
  2028. during the installation phase are written to the target disk on @file{/mnt}
  2029. rather than kept in memory. This is necessary because the first phase of
  2030. the @command{guix system init} command (see below) entails downloads or
  2031. builds to @file{/gnu/store} which, initially, is an in-memory file system.
  2032. Next, you have to edit a file and
  2033. provide the declaration of the operating system to be installed. To
  2034. that end, the installation system comes with three text editors. We
  2035. recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
  2036. supports syntax highlighting and parentheses matching; other editors
  2037. include GNU Zile (an Emacs clone), and
  2038. nvi (a clone of the original BSD @command{vi} editor).
  2039. We strongly recommend storing that file on the target root file system, say,
  2040. as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
  2041. configuration file once you have rebooted into the newly-installed system.
  2042. @xref{Using the Configuration System}, for an overview of the
  2043. configuration file. The example configurations discussed in that
  2044. section are available under @file{/etc/configuration} in the
  2045. installation image. Thus, to get started with a system configuration
  2046. providing a graphical display server (a ``desktop'' system), you can run
  2047. something along these lines:
  2048. @example
  2049. # mkdir /mnt/etc
  2050. # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
  2051. # nano /mnt/etc/config.scm
  2052. @end example
  2053. You should pay attention to what your configuration file contains, and
  2054. in particular:
  2055. @itemize
  2056. @item
  2057. Make sure the @code{bootloader-configuration} form refers to the target
  2058. you want to install GRUB on. It should mention @code{grub-bootloader} if
  2059. you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
  2060. for newer UEFI systems. For legacy systems, the @code{target} field
  2061. names a device, like @code{/dev/sda}; for UEFI systems it names a path
  2062. to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
  2063. currently mounted and a @code{file-system} entry is specified in your
  2064. configuration.
  2065. @item
  2066. Be sure that your file system labels match the value of their respective
  2067. @code{device} fields in your @code{file-system} configuration, assuming
  2068. your @code{file-system} configuration uses the @code{file-system-label}
  2069. procedure in its @code{device} field.
  2070. @item
  2071. If there are encrypted or RAID partitions, make sure to add a
  2072. @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
  2073. @end itemize
  2074. Once you are done preparing the configuration file, the new system must
  2075. be initialized (remember that the target root file system is mounted
  2076. under @file{/mnt}):
  2077. @example
  2078. guix system init /mnt/etc/config.scm /mnt
  2079. @end example
  2080. @noindent
  2081. This copies all the necessary files and installs GRUB on
  2082. @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
  2083. more information, @pxref{Invoking guix system}. This command may trigger
  2084. downloads or builds of missing packages, which can take some time.
  2085. Once that command has completed---and hopefully succeeded!---you can run
  2086. @command{reboot} and boot into the new system. The @code{root} password
  2087. in the new system is initially empty; other users' passwords need to be
  2088. initialized by running the @command{passwd} command as @code{root},
  2089. unless your configuration specifies otherwise
  2090. (@pxref{user-account-password, user account passwords}).
  2091. @xref{After System Installation}, for what's next!
  2092. @node After System Installation
  2093. @section After System Installation
  2094. Success, you've now booted into Guix System! From then on, you can update the
  2095. system whenever you want by running, say:
  2096. @example
  2097. guix pull
  2098. sudo guix system reconfigure /etc/config.scm
  2099. @end example
  2100. @noindent
  2101. This builds a new system generation with the latest packages and services
  2102. (@pxref{Invoking guix system}). We recommend doing that regularly so that
  2103. your system includes the latest security updates (@pxref{Security Updates}).
  2104. @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
  2105. @quotation Note
  2106. @cindex sudo vs. @command{guix pull}
  2107. Note that @command{sudo guix} runs your user's @command{guix} command and
  2108. @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
  2109. explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
  2110. The difference matters here, because @command{guix pull} updates
  2111. the @command{guix} command and package definitions only for the user it is run
  2112. as. This means that if you choose to use @command{guix system reconfigure} in
  2113. root's login shell, you'll need to @command{guix pull} separately.
  2114. @end quotation
  2115. Now, @pxref{Getting Started}, and
  2116. join us on @code{#guix} on the Freenode IRC network or on
  2117. @email{guix-devel@@gnu.org} to share your experience!
  2118. @node Installing Guix in a VM
  2119. @section Installing Guix in a Virtual Machine
  2120. @cindex virtual machine, Guix System installation
  2121. @cindex virtual private server (VPS)
  2122. @cindex VPS (virtual private server)
  2123. If you'd like to install Guix System in a virtual machine (VM) or on a
  2124. virtual private server (VPS) rather than on your beloved machine, this
  2125. section is for you.
  2126. To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
  2127. disk image, follow these steps:
  2128. @enumerate
  2129. @item
  2130. First, retrieve and decompress the Guix system installation image as
  2131. described previously (@pxref{USB Stick and DVD Installation}).
  2132. @item
  2133. Create a disk image that will hold the installed system. To make a
  2134. qcow2-formatted disk image, use the @command{qemu-img} command:
  2135. @example
  2136. qemu-img create -f qcow2 guix-system.img 50G
  2137. @end example
  2138. The resulting file will be much smaller than 50 GB (typically less than
  2139. 1 MB), but it will grow as the virtualized storage device is filled up.
  2140. @item
  2141. Boot the USB installation image in an VM:
  2142. @example
  2143. qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
  2144. -nic user,model=virtio-net-pci -boot menu=on,order=d \
  2145. -drive file=guix-system.img \
  2146. -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
  2147. @end example
  2148. @code{-enable-kvm} is optional, but significantly improves performance,
  2149. @pxref{Running Guix in a VM}.
  2150. @item
  2151. You're now root in the VM, proceed with the installation process.
  2152. @xref{Preparing for Installation}, and follow the instructions.
  2153. @end enumerate
  2154. Once installation is complete, you can boot the system that's on your
  2155. @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
  2156. that.
  2157. @node Building the Installation Image
  2158. @section Building the Installation Image
  2159. @cindex installation image
  2160. The installation image described above was built using the @command{guix
  2161. system} command, specifically:
  2162. @example
  2163. guix system image -t iso9660 gnu/system/install.scm
  2164. @end example
  2165. Have a look at @file{gnu/system/install.scm} in the source tree,
  2166. and see also @ref{Invoking guix system} for more information
  2167. about the installation image.
  2168. @section Building the Installation Image for ARM Boards
  2169. Many ARM boards require a specific variant of the
  2170. @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
  2171. If you build a disk image and the bootloader is not available otherwise
  2172. (on another boot drive etc), it's advisable to build an image that
  2173. includes the bootloader, specifically:
  2174. @example
  2175. guix system image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
  2176. @end example
  2177. @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
  2178. board, a list of possible boards will be printed.
  2179. @c *********************************************************************
  2180. @node Getting Started
  2181. @chapter Getting Started
  2182. Presumably, you've reached this section because either you have
  2183. installed Guix on top of another distribution (@pxref{Installation}), or
  2184. you've installed the standalone Guix System (@pxref{System
  2185. Installation}). It's time for you to get started using Guix and this
  2186. section aims to help you do that and give you a feel of what it's like.
  2187. Guix is about installing software, so probably the first thing you'll
  2188. want to do is to actually look for software. Let's say you're looking
  2189. for a text editor, you can run:
  2190. @example
  2191. guix search text editor
  2192. @end example
  2193. This command shows you a number of matching @dfn{packages}, each time
  2194. showing the package's name, version, a description, and additional info.
  2195. Once you've found out the one you want to use, let's say Emacs (ah ha!),
  2196. you can go ahead and install it (run this command as a regular user,
  2197. @emph{no need for root privileges}!):
  2198. @example
  2199. guix install emacs
  2200. @end example
  2201. @cindex profile
  2202. You've installed your first package, congrats! The package is now
  2203. visible in your default @dfn{profile}, @file{$HOME/.guix-profile}---a
  2204. profile is a directory containing installed packages.
  2205. In the process, you've
  2206. probably noticed that Guix downloaded pre-built binaries; or, if you
  2207. explicitly chose to @emph{not} use pre-built binaries, then probably
  2208. Guix is still building software (@pxref{Substitutes}, for more info).
  2209. Unless you're using Guix System, the @command{guix install} command must
  2210. have printed this hint:
  2211. @example
  2212. hint: Consider setting the necessary environment variables by running:
  2213. GUIX_PROFILE="$HOME/.guix-profile"
  2214. . "$GUIX_PROFILE/etc/profile"
  2215. Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
  2216. @end example
  2217. Indeed, you must now tell your shell where @command{emacs} and other
  2218. programs installed with Guix are to be found. Pasting the two lines
  2219. above will do just that: it will add
  2220. @code{$HOME/.guix-profile/bin}---which is where the installed package
  2221. is---to the @code{PATH} environment variable. You can paste these two
  2222. lines in your shell so they take effect right away, but more importantly
  2223. you should add them to @file{~/.bash_profile} (or equivalent file if you
  2224. do not use Bash) so that environment variables are set next time you
  2225. spawn a shell. You only need to do this once and other search paths
  2226. environment variables will be taken care of similarly---e.g., if you
  2227. eventually install @code{python} and Python libraries, @code{PYTHONPATH}
  2228. will be defined.
  2229. You can go on installing packages at your will. To list installed
  2230. packages, run:
  2231. @example
  2232. guix package --list-installed
  2233. @end example
  2234. To remove a package, you would unsurprisingly run @command{guix remove}.
  2235. A distinguishing feature is the ability to @dfn{roll back} any operation
  2236. you made---installation, removal, upgrade---by simply typing:
  2237. @example
  2238. guix package --roll-back
  2239. @end example
  2240. This is because each operation is in fact a @dfn{transaction} that
  2241. creates a new @dfn{generation}. These generations and the difference
  2242. between them can be displayed by running:
  2243. @example
  2244. guix package --list-generations
  2245. @end example
  2246. Now you know the basics of package management!
  2247. @quotation Going further
  2248. @xref{Package Management}, for more about package management. You may
  2249. like @dfn{declarative} package management with @command{guix package
  2250. --manifest}, managing separate @dfn{profiles} with @option{--profile},
  2251. deleting old generations, collecting garbage, and other nifty features
  2252. that will come in handy as you become more familiar with Guix. If you
  2253. are a developer, @pxref{Development} for additional tools. And if
  2254. you're curious, @pxref{Features}, to peek under the hood.
  2255. @end quotation
  2256. Once you've installed a set of packages, you will want to periodically
  2257. @emph{upgrade} them to the latest and greatest version. To do that, you
  2258. will first pull the latest revision of Guix and its package collection:
  2259. @example
  2260. guix pull
  2261. @end example
  2262. The end result is a new @command{guix} command, under
  2263. @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
  2264. first time you run @command{guix pull}, be sure to follow the hint that
  2265. the command prints and, similar to what we saw above, paste these two
  2266. lines in your terminal and @file{.bash_profile}:
  2267. @example
  2268. GUIX_PROFILE="$HOME/.config/guix/current"
  2269. . "$GUIX_PROFILE/etc/profile"
  2270. @end example
  2271. @noindent
  2272. You must also instruct your shell to point to this new @command{guix}:
  2273. @example
  2274. hash guix
  2275. @end example
  2276. At this point, you're running a brand new Guix. You can thus go ahead
  2277. and actually upgrade all the packages you previously installed:
  2278. @example
  2279. guix upgrade
  2280. @end example
  2281. As you run this command, you will see that binaries are downloaded (or
  2282. perhaps some packages are built), and eventually you end up with the
  2283. upgraded packages. Should one of these upgraded packages not be to your
  2284. liking, remember you can always roll back!
  2285. You can display the exact revision of Guix you're currently using by
  2286. running:
  2287. @example
  2288. guix describe
  2289. @end example
  2290. The information it displays is @emph{all it takes to reproduce the exact
  2291. same Guix}, be it at a different point in time or on a different
  2292. machine.
  2293. @quotation Going further
  2294. @xref{Invoking guix pull}, for more information. @xref{Channels}, on
  2295. how to specify additional @dfn{channels} to pull packages from, how to
  2296. replicate Guix, and more. You may also find @command{time-machine}
  2297. handy (@pxref{Invoking guix time-machine}).
  2298. @end quotation
  2299. If you installed Guix System, one of the first things you'll want to do
  2300. is to upgrade your system. Once you've run @command{guix pull} to get
  2301. the latest Guix, you can upgrade the system like this:
  2302. @example
  2303. sudo guix system reconfigure /etc/config.scm
  2304. @end example
  2305. Upon completion, the system runs the latest versions of its software
  2306. packages. When you eventually reboot, you'll notice a sub-menu in the
  2307. bootloader that reads ``Old system generations'': it's what allows you
  2308. to boot @emph{an older generation of your system}, should the latest
  2309. generation be ``broken'' or otherwise unsatisfying. Just like for
  2310. packages, you can always @emph{roll back} to a previous generation
  2311. @emph{of the whole system}:
  2312. @example
  2313. sudo guix system roll-back
  2314. @end example
  2315. There are many things you'll probably want to tweak on your system:
  2316. adding new user accounts, adding new system services, fiddling with the
  2317. configuration of those services, etc. The system configuration is
  2318. @emph{entirely} described in the @file{/etc/config.scm} file.
  2319. @xref{Using the Configuration System}, to learn how to change it.
  2320. Now you know enough to get started!
  2321. @quotation Resources
  2322. The rest of this manual provides a reference for all things Guix. Here
  2323. are some additional resources you may find useful:
  2324. @itemize
  2325. @item
  2326. @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
  2327. ``how-to'' style of recipes for a variety of applications.
  2328. @item
  2329. The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
  2330. Card} lists in two pages most of the commands and options you'll ever
  2331. need.
  2332. @item
  2333. The web site contains @uref{https://guix.gnu.org/en/videos/,
  2334. instructional videos} covering topics such as everyday use of Guix, how
  2335. to get help, and how to become a contributor.
  2336. @item
  2337. @xref{Documentation}, to learn how to access documentation on your
  2338. computer.
  2339. @end itemize
  2340. We hope you will enjoy Guix as much as the community enjoys building it!
  2341. @end quotation
  2342. @c *********************************************************************
  2343. @node Package Management
  2344. @chapter Package Management
  2345. @cindex packages
  2346. The purpose of GNU Guix is to allow users to easily install, upgrade, and
  2347. remove software packages, without having to know about their build
  2348. procedures or dependencies. Guix also goes beyond this obvious set of
  2349. features.
  2350. This chapter describes the main features of Guix, as well as the
  2351. package management tools it provides. Along with the command-line
  2352. interface described below (@pxref{Invoking guix package, @code{guix
  2353. package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
  2354. emacs-guix, The Emacs-Guix Reference Manual}), after installing
  2355. @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
  2356. with it):
  2357. @example
  2358. guix install emacs-guix
  2359. @end example
  2360. @menu
  2361. * Features:: How Guix will make your life brighter.
  2362. * Invoking guix package:: Package installation, removal, etc.
  2363. * Substitutes:: Downloading pre-built binaries.
  2364. * Packages with Multiple Outputs:: Single source package, multiple outputs.
  2365. * Invoking guix gc:: Running the garbage collector.
  2366. * Invoking guix pull:: Fetching the latest Guix and distribution.
  2367. * Invoking guix time-machine:: Running an older revision of Guix.
  2368. * Inferiors:: Interacting with another revision of Guix.
  2369. * Invoking guix describe:: Display information about your Guix revision.
  2370. * Invoking guix archive:: Exporting and importing store files.
  2371. @end menu
  2372. @node Features
  2373. @section Features
  2374. Here we assume you've already made your first steps with Guix
  2375. (@pxref{Getting Started}) and would like to get an overview about what's
  2376. going on under the hood.
  2377. When using Guix, each package ends up in the @dfn{package store}, in its
  2378. own directory---something that resembles
  2379. @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
  2380. Instead of referring to these directories, users have their own
  2381. @dfn{profile}, which points to the packages that they actually want to
  2382. use. These profiles are stored within each user's home directory, at
  2383. @code{$HOME/.guix-profile}.
  2384. For example, @code{alice} installs GCC 4.7.2. As a result,
  2385. @file{/home/alice/.guix-profile/bin/gcc} points to
  2386. @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
  2387. @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
  2388. simply continues to point to
  2389. @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
  2390. coexist on the same system without any interference.
  2391. The @command{guix package} command is the central tool to manage
  2392. packages (@pxref{Invoking guix package}). It operates on the per-user
  2393. profiles, and can be used @emph{with normal user privileges}.
  2394. @cindex transactions
  2395. The command provides the obvious install, remove, and upgrade
  2396. operations. Each invocation is actually a @emph{transaction}: either
  2397. the specified operation succeeds, or nothing happens. Thus, if the
  2398. @command{guix package} process is terminated during the transaction,
  2399. or if a power outage occurs during the transaction, then the user's
  2400. profile remains in its previous state, and remains usable.
  2401. In addition, any package transaction may be @emph{rolled back}. So, if,
  2402. for example, an upgrade installs a new version of a package that turns
  2403. out to have a serious bug, users may roll back to the previous instance
  2404. of their profile, which was known to work well. Similarly, the global
  2405. system configuration on Guix is subject to
  2406. transactional upgrades and roll-back
  2407. (@pxref{Using the Configuration System}).
  2408. All packages in the package store may be @emph{garbage-collected}.
  2409. Guix can determine which packages are still referenced by user
  2410. profiles, and remove those that are provably no longer referenced
  2411. (@pxref{Invoking guix gc}). Users may also explicitly remove old
  2412. generations of their profile so that the packages they refer to can be
  2413. collected.
  2414. @cindex reproducibility
  2415. @cindex reproducible builds
  2416. Guix takes a @dfn{purely functional} approach to package
  2417. management, as described in the introduction (@pxref{Introduction}).
  2418. Each @file{/gnu/store} package directory name contains a hash of all the
  2419. inputs that were used to build that package---compiler, libraries, build
  2420. scripts, etc. This direct correspondence allows users to make sure a
  2421. given package installation matches the current state of their
  2422. distribution. It also helps maximize @dfn{build reproducibility}:
  2423. thanks to the isolated build environments that are used, a given build
  2424. is likely to yield bit-identical files when performed on different
  2425. machines (@pxref{Invoking guix-daemon, container}).
  2426. @cindex substitutes
  2427. This foundation allows Guix to support @dfn{transparent binary/source
  2428. deployment}. When a pre-built binary for a @file{/gnu/store} item is
  2429. available from an external source---a @dfn{substitute}, Guix just
  2430. downloads it and unpacks it;
  2431. otherwise, it builds the package from source, locally
  2432. (@pxref{Substitutes}). Because build results are usually bit-for-bit
  2433. reproducible, users do not have to trust servers that provide
  2434. substitutes: they can force a local build and @emph{challenge} providers
  2435. (@pxref{Invoking guix challenge}).
  2436. Control over the build environment is a feature that is also useful for
  2437. developers. The @command{guix environment} command allows developers of
  2438. a package to quickly set up the right development environment for their
  2439. package, without having to manually install the dependencies of the
  2440. package into their profile (@pxref{Invoking guix environment}).
  2441. @cindex replication, of software environments
  2442. @cindex provenance tracking, of software artifacts
  2443. All of Guix and its package definitions is version-controlled, and
  2444. @command{guix pull} allows you to ``travel in time'' on the history of Guix
  2445. itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
  2446. Guix instance on a different machine or at a later point in time, which in
  2447. turn allows you to @emph{replicate complete software environments}, while
  2448. retaining precise @dfn{provenance tracking} of the software.
  2449. @node Invoking guix package
  2450. @section Invoking @command{guix package}
  2451. @cindex installing packages
  2452. @cindex removing packages
  2453. @cindex package installation
  2454. @cindex package removal
  2455. @cindex profile
  2456. The @command{guix package} command is the tool that allows users to
  2457. install, upgrade, and remove packages, as well as rolling back to
  2458. previous configurations. These operations work on a user
  2459. @dfn{profile}---a directory of installed packages. Each user has a
  2460. default profile in @file{$HOME/.guix-profile}.
  2461. The command operates only on the user's own profile,
  2462. and works with normal user privileges (@pxref{Features}). Its syntax
  2463. is:
  2464. @example
  2465. guix package @var{options}
  2466. @end example
  2467. @cindex transactions
  2468. Primarily, @var{options} specifies the operations to be performed during
  2469. the transaction. Upon completion, a new profile is created, but
  2470. previous @dfn{generations} of the profile remain available, should the user
  2471. want to roll back.
  2472. For example, to remove @code{lua} and install @code{guile} and
  2473. @code{guile-cairo} in a single transaction:
  2474. @example
  2475. guix package -r lua -i guile guile-cairo
  2476. @end example
  2477. @cindex aliases, for @command{guix package}
  2478. For your convenience, we also provide the following aliases:
  2479. @itemize
  2480. @item
  2481. @command{guix search} is an alias for @command{guix package -s},
  2482. @item
  2483. @command{guix install} is an alias for @command{guix package -i},
  2484. @item
  2485. @command{guix remove} is an alias for @command{guix package -r},
  2486. @item
  2487. @command{guix upgrade} is an alias for @command{guix package -u},
  2488. @item
  2489. and @command{guix show} is an alias for @command{guix package --show=}.
  2490. @end itemize
  2491. These aliases are less expressive than @command{guix package} and provide
  2492. fewer options, so in some cases you'll probably want to use @command{guix
  2493. package} directly.
  2494. @command{guix package} also supports a @dfn{declarative approach}
  2495. whereby the user specifies the exact set of packages to be available and
  2496. passes it @i{via} the @option{--manifest} option
  2497. (@pxref{profile-manifest, @option{--manifest}}).
  2498. @cindex profile
  2499. For each user, a symlink to the user's default profile is automatically
  2500. created in @file{$HOME/.guix-profile}. This symlink always points to the
  2501. current generation of the user's default profile. Thus, users can add
  2502. @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
  2503. variable, and so on.
  2504. @cindex search paths
  2505. If you are not using Guix System, consider adding the
  2506. following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
  2507. Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
  2508. shells get all the right environment variable definitions:
  2509. @example
  2510. GUIX_PROFILE="$HOME/.guix-profile" ; \
  2511. source "$GUIX_PROFILE/etc/profile"
  2512. @end example
  2513. In a multi-user setup, user profiles are stored in a place registered as
  2514. a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
  2515. to (@pxref{Invoking guix gc}). That directory is normally
  2516. @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
  2517. @var{localstatedir} is the value passed to @code{configure} as
  2518. @option{--localstatedir}, and @var{user} is the user name. The
  2519. @file{per-user} directory is created when @command{guix-daemon} is
  2520. started, and the @var{user} sub-directory is created by @command{guix
  2521. package}.
  2522. The @var{options} can be among the following:
  2523. @table @code
  2524. @item --install=@var{package} @dots{}
  2525. @itemx -i @var{package} @dots{}
  2526. Install the specified @var{package}s.
  2527. Each @var{package} may specify either a simple package name, such as
  2528. @code{guile}, or a package name followed by an at-sign and version number,
  2529. such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
  2530. case, the newest version prefixed by @code{1.8} is selected).
  2531. If no version number is specified, the
  2532. newest available version will be selected. In addition, @var{package}
  2533. may contain a colon, followed by the name of one of the outputs of the
  2534. package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
  2535. (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
  2536. name (and optionally version) are searched for among the GNU
  2537. distribution modules (@pxref{Package Modules}).
  2538. @cindex propagated inputs
  2539. Sometimes packages have @dfn{propagated inputs}: these are dependencies
  2540. that automatically get installed along with the required package
  2541. (@pxref{package-propagated-inputs, @code{propagated-inputs} in
  2542. @code{package} objects}, for information about propagated inputs in
  2543. package definitions).
  2544. @anchor{package-cmd-propagated-inputs}
  2545. An example is the GNU MPC library: its C header files refer to those of
  2546. the GNU MPFR library, which in turn refer to those of the GMP library.
  2547. Thus, when installing MPC, the MPFR and GMP libraries also get installed
  2548. in the profile; removing MPC also removes MPFR and GMP---unless they had
  2549. also been explicitly installed by the user.
  2550. Besides, packages sometimes rely on the definition of environment
  2551. variables for their search paths (see explanation of
  2552. @option{--search-paths} below). Any missing or possibly incorrect
  2553. environment variable definitions are reported here.
  2554. @item --install-from-expression=@var{exp}
  2555. @itemx -e @var{exp}
  2556. Install the package @var{exp} evaluates to.
  2557. @var{exp} must be a Scheme expression that evaluates to a
  2558. @code{<package>} object. This option is notably useful to disambiguate
  2559. between same-named variants of a package, with expressions such as
  2560. @code{(@@ (gnu packages base) guile-final)}.
  2561. Note that this option installs the first output of the specified
  2562. package, which may be insufficient when needing a specific output of a
  2563. multiple-output package.
  2564. @item --install-from-file=@var{file}
  2565. @itemx -f @var{file}
  2566. Install the package that the code within @var{file} evaluates to.
  2567. As an example, @var{file} might contain a definition like this
  2568. (@pxref{Defining Packages}):
  2569. @lisp
  2570. @include package-hello.scm
  2571. @end lisp
  2572. Developers may find it useful to include such a @file{guix.scm} file
  2573. in the root of their project source tree that can be used to test
  2574. development snapshots and create reproducible development environments
  2575. (@pxref{Invoking guix environment}).
  2576. The @var{file} may also contain a JSON representation of one or more
  2577. package definitions. Running @code{guix package -f} on
  2578. @file{hello.json} with the following contents would result in installing
  2579. the package @code{greeter} after building @code{myhello}:
  2580. @example
  2581. @verbatiminclude package-hello.json
  2582. @end example
  2583. @item --remove=@var{package} @dots{}
  2584. @itemx -r @var{package} @dots{}
  2585. Remove the specified @var{package}s.
  2586. As for @option{--install}, each @var{package} may specify a version number
  2587. and/or output name in addition to the package name. For instance,
  2588. @samp{-r glibc:debug} would remove the @code{debug} output of
  2589. @code{glibc}.
  2590. @item --upgrade[=@var{regexp} @dots{}]
  2591. @itemx -u [@var{regexp} @dots{}]
  2592. @cindex upgrading packages
  2593. Upgrade all the installed packages. If one or more @var{regexp}s are
  2594. specified, upgrade only installed packages whose name matches a
  2595. @var{regexp}. Also see the @option{--do-not-upgrade} option below.
  2596. Note that this upgrades package to the latest version of packages found
  2597. in the distribution currently installed. To update your distribution,
  2598. you should regularly run @command{guix pull} (@pxref{Invoking guix
  2599. pull}).
  2600. @cindex package transformations, upgrades
  2601. When upgrading, package transformations that were originally applied
  2602. when creating the profile are automatically re-applied (@pxref{Package
  2603. Transformation Options}). For example, assume you first installed Emacs
  2604. from the tip of its development branch with:
  2605. @example
  2606. guix install emacs-next --with-branch=emacs-next=master
  2607. @end example
  2608. Next time you run @command{guix upgrade}, Guix will again pull the tip
  2609. of the Emacs development branch and build @code{emacs-next} from that
  2610. checkout.
  2611. Note that transformation options such as @option{--with-branch} and
  2612. @option{--with-source} depend on external state; it is up to you to
  2613. ensure that they work as expected. You can also discard a
  2614. transformations that apply to a package by running:
  2615. @example
  2616. guix install @var{package}
  2617. @end example
  2618. @item --do-not-upgrade[=@var{regexp} @dots{}]
  2619. When used together with the @option{--upgrade} option, do @emph{not}
  2620. upgrade any packages whose name matches a @var{regexp}. For example, to
  2621. upgrade all packages in the current profile except those containing the
  2622. substring ``emacs'':
  2623. @example
  2624. $ guix package --upgrade . --do-not-upgrade emacs
  2625. @end example
  2626. @item @anchor{profile-manifest}--manifest=@var{file}
  2627. @itemx -m @var{file}
  2628. @cindex profile declaration
  2629. @cindex profile manifest
  2630. Create a new generation of the profile from the manifest object
  2631. returned by the Scheme code in @var{file}. This option can be repeated
  2632. several times, in which case the manifests are concatenated.
  2633. This allows you to @emph{declare} the profile's contents rather than
  2634. constructing it through a sequence of @option{--install} and similar
  2635. commands. The advantage is that @var{file} can be put under version
  2636. control, copied to different machines to reproduce the same profile, and
  2637. so on.
  2638. @c FIXME: Add reference to (guix profile) documentation when available.
  2639. @var{file} must return a @dfn{manifest} object, which is roughly a list
  2640. of packages:
  2641. @findex packages->manifest
  2642. @lisp
  2643. (use-package-modules guile emacs)
  2644. (packages->manifest
  2645. (list emacs
  2646. guile-2.0
  2647. ;; Use a specific package output.
  2648. (list guile-2.0 "debug")))
  2649. @end lisp
  2650. @findex specifications->manifest
  2651. In this example we have to know which modules define the @code{emacs}
  2652. and @code{guile-2.0} variables to provide the right
  2653. @code{use-package-modules} line, which can be cumbersome. We can
  2654. instead provide regular package specifications and let
  2655. @code{specifications->manifest} look up the corresponding package
  2656. objects, like this:
  2657. @lisp
  2658. (specifications->manifest
  2659. '("emacs" "guile@@2.2" "guile@@2.2:debug"))
  2660. @end lisp
  2661. @xref{export-manifest, @option{--export-manifest}}, to learn how to
  2662. obtain a manifest file from an existing profile.
  2663. @item --roll-back
  2664. @cindex rolling back
  2665. @cindex undoing transactions
  2666. @cindex transactions, undoing
  2667. Roll back to the previous @dfn{generation} of the profile---i.e., undo
  2668. the last transaction.
  2669. When combined with options such as @option{--install}, roll back occurs
  2670. before any other actions.
  2671. When rolling back from the first generation that actually contains
  2672. installed packages, the profile is made to point to the @dfn{zeroth
  2673. generation}, which contains no files apart from its own metadata.
  2674. After having rolled back, installing, removing, or upgrading packages
  2675. overwrites previous future generations. Thus, the history of the
  2676. generations in a profile is always linear.
  2677. @item --switch-generation=@var{pattern}
  2678. @itemx -S @var{pattern}
  2679. @cindex generations
  2680. Switch to a particular generation defined by @var{pattern}.
  2681. @var{pattern} may be either a generation number or a number prefixed
  2682. with ``+'' or ``-''. The latter means: move forward/backward by a
  2683. specified number of generations. For example, if you want to return to
  2684. the latest generation after @option{--roll-back}, use
  2685. @option{--switch-generation=+1}.
  2686. The difference between @option{--roll-back} and
  2687. @option{--switch-generation=-1} is that @option{--switch-generation} will
  2688. not make a zeroth generation, so if a specified generation does not
  2689. exist, the current generation will not be changed.
  2690. @item --search-paths[=@var{kind}]
  2691. @cindex search paths
  2692. Report environment variable definitions, in Bash syntax, that may be
  2693. needed in order to use the set of installed packages. These environment
  2694. variables are used to specify @dfn{search paths} for files used by some
  2695. of the installed packages.
  2696. For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
  2697. environment variables to be defined so it can look for headers and
  2698. libraries in the user's profile (@pxref{Environment Variables,,, gcc,
  2699. Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
  2700. library are installed in the profile, then @option{--search-paths} will
  2701. suggest setting these variables to @file{@var{profile}/include} and
  2702. @file{@var{profile}/lib}, respectively.
  2703. The typical use case is to define these environment variables in the
  2704. shell:
  2705. @example
  2706. $ eval `guix package --search-paths`
  2707. @end example
  2708. @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
  2709. meaning that the returned environment variable definitions will either
  2710. be exact settings, or prefixes or suffixes of the current value of these
  2711. variables. When omitted, @var{kind} defaults to @code{exact}.
  2712. This option can also be used to compute the @emph{combined} search paths
  2713. of several profiles. Consider this example:
  2714. @example
  2715. $ guix package -p foo -i guile
  2716. $ guix package -p bar -i guile-json
  2717. $ guix package -p foo -p bar --search-paths
  2718. @end example
  2719. The last command above reports about the @env{GUILE_LOAD_PATH}
  2720. variable, even though, taken individually, neither @file{foo} nor
  2721. @file{bar} would lead to that recommendation.
  2722. @cindex profile, choosing
  2723. @item --profile=@var{profile}
  2724. @itemx -p @var{profile}
  2725. Use @var{profile} instead of the user's default profile.
  2726. @var{profile} must be the name of a file that will be created upon
  2727. completion. Concretely, @var{profile} will be a mere symbolic link
  2728. (``symlink'') pointing to the actual profile where packages are
  2729. installed:
  2730. @example
  2731. $ guix install hello -p ~/code/my-profile
  2732. @dots{}
  2733. $ ~/code/my-profile/bin/hello
  2734. Hello, world!
  2735. @end example
  2736. All it takes to get rid of the profile is to remove this symlink and its
  2737. siblings that point to specific generations:
  2738. @example
  2739. $ rm ~/code/my-profile ~/code/my-profile-*-link
  2740. @end example
  2741. @item --list-profiles
  2742. List all the user's profiles:
  2743. @example
  2744. $ guix package --list-profiles
  2745. /home/charlie/.guix-profile
  2746. /home/charlie/code/my-profile
  2747. /home/charlie/code/devel-profile
  2748. /home/charlie/tmp/test
  2749. @end example
  2750. When running as root, list all the profiles of all the users.
  2751. @cindex collisions, in a profile
  2752. @cindex colliding packages in profiles
  2753. @cindex profile collisions
  2754. @item --allow-collisions
  2755. Allow colliding packages in the new profile. Use at your own risk!
  2756. By default, @command{guix package} reports as an error @dfn{collisions}
  2757. in the profile. Collisions happen when two or more different versions
  2758. or variants of a given package end up in the profile.
  2759. @item --bootstrap
  2760. Use the bootstrap Guile to build the profile. This option is only
  2761. useful to distribution developers.
  2762. @end table
  2763. In addition to these actions, @command{guix package} supports the
  2764. following options to query the current state of a profile, or the
  2765. availability of packages:
  2766. @table @option
  2767. @item --search=@var{regexp}
  2768. @itemx -s @var{regexp}
  2769. @anchor{guix-search}
  2770. @cindex searching for packages
  2771. List the available packages whose name, synopsis, or description matches
  2772. @var{regexp} (in a case-insensitive fashion), sorted by relevance.
  2773. Print all the metadata of matching packages in
  2774. @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
  2775. GNU recutils manual}).
  2776. This allows specific fields to be extracted using the @command{recsel}
  2777. command, for instance:
  2778. @example
  2779. $ guix package -s malloc | recsel -p name,version,relevance
  2780. name: jemalloc
  2781. version: 4.5.0
  2782. relevance: 6
  2783. name: glibc
  2784. version: 2.25
  2785. relevance: 1
  2786. name: libgc
  2787. version: 7.6.0
  2788. relevance: 1
  2789. @end example
  2790. Similarly, to show the name of all the packages available under the
  2791. terms of the GNU@tie{}LGPL version 3:
  2792. @example
  2793. $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
  2794. name: elfutils
  2795. name: gmp
  2796. @dots{}
  2797. @end example
  2798. It is also possible to refine search results using several @code{-s} flags to
  2799. @command{guix package}, or several arguments to @command{guix search}. For
  2800. example, the following command returns a list of board games (this time using
  2801. the @command{guix search} alias):
  2802. @example
  2803. $ guix search '\<board\>' game | recsel -p name
  2804. name: gnubg
  2805. @dots{}
  2806. @end example
  2807. If we were to omit @code{-s game}, we would also get software packages
  2808. that deal with printed circuit boards; removing the angle brackets
  2809. around @code{board} would further add packages that have to do with
  2810. keyboards.
  2811. And now for a more elaborate example. The following command searches
  2812. for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
  2813. libraries, and prints the name and synopsis of the matching packages:
  2814. @example
  2815. $ guix search crypto library | \
  2816. recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
  2817. @end example
  2818. @noindent
  2819. @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
  2820. information on @dfn{selection expressions} for @code{recsel -e}.
  2821. @item --show=@var{package}
  2822. Show details about @var{package}, taken from the list of available packages, in
  2823. @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
  2824. recutils manual}).
  2825. @example
  2826. $ guix package --show=python | recsel -p name,version
  2827. name: python
  2828. version: 2.7.6
  2829. name: python
  2830. version: 3.3.5
  2831. @end example
  2832. You may also specify the full name of a package to only get details about a
  2833. specific version of it (this time using the @command{guix show} alias):
  2834. @example
  2835. $ guix show python@@3.4 | recsel -p name,version
  2836. name: python
  2837. version: 3.4.3
  2838. @end example
  2839. @item --list-installed[=@var{regexp}]
  2840. @itemx -I [@var{regexp}]
  2841. List the currently installed packages in the specified profile, with the
  2842. most recently installed packages shown last. When @var{regexp} is
  2843. specified, list only installed packages whose name matches @var{regexp}.
  2844. For each installed package, print the following items, separated by
  2845. tabs: the package name, its version string, the part of the package that
  2846. is installed (for instance, @code{out} for the default output,
  2847. @code{include} for its headers, etc.), and the path of this package in
  2848. the store.
  2849. @item --list-available[=@var{regexp}]
  2850. @itemx -A [@var{regexp}]
  2851. List packages currently available in the distribution for this system
  2852. (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
  2853. available packages whose name matches @var{regexp}.
  2854. For each package, print the following items separated by tabs: its name,
  2855. its version string, the parts of the package (@pxref{Packages with
  2856. Multiple Outputs}), and the source location of its definition.
  2857. @item --list-generations[=@var{pattern}]
  2858. @itemx -l [@var{pattern}]
  2859. @cindex generations
  2860. Return a list of generations along with their creation dates; for each
  2861. generation, show the installed packages, with the most recently
  2862. installed packages shown last. Note that the zeroth generation is never
  2863. shown.
  2864. For each installed package, print the following items, separated by
  2865. tabs: the name of a package, its version string, the part of the package
  2866. that is installed (@pxref{Packages with Multiple Outputs}), and the
  2867. location of this package in the store.
  2868. When @var{pattern} is used, the command returns only matching
  2869. generations. Valid patterns include:
  2870. @itemize
  2871. @item @emph{Integers and comma-separated integers}. Both patterns denote
  2872. generation numbers. For instance, @option{--list-generations=1} returns
  2873. the first one.
  2874. And @option{--list-generations=1,8,2} outputs three generations in the
  2875. specified order. Neither spaces nor trailing commas are allowed.
  2876. @item @emph{Ranges}. @option{--list-generations=2..9} prints the
  2877. specified generations and everything in between. Note that the start of
  2878. a range must be smaller than its end.
  2879. It is also possible to omit the endpoint. For example,
  2880. @option{--list-generations=2..}, returns all generations starting from the
  2881. second one.
  2882. @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
  2883. or months by passing an integer along with the first letter of the
  2884. duration. For example, @option{--list-generations=20d} lists generations
  2885. that are up to 20 days old.
  2886. @end itemize
  2887. @item --delete-generations[=@var{pattern}]
  2888. @itemx -d [@var{pattern}]
  2889. When @var{pattern} is omitted, delete all generations except the current
  2890. one.
  2891. This command accepts the same patterns as @option{--list-generations}.
  2892. When @var{pattern} is specified, delete the matching generations. When
  2893. @var{pattern} specifies a duration, generations @emph{older} than the
  2894. specified duration match. For instance, @option{--delete-generations=1m}
  2895. deletes generations that are more than one month old.
  2896. If the current generation matches, it is @emph{not} deleted. Also, the
  2897. zeroth generation is never deleted.
  2898. Note that deleting generations prevents rolling back to them.
  2899. Consequently, this command must be used with care.
  2900. @cindex manifest, exporting
  2901. @anchor{export-manifest}
  2902. @item --export-manifest
  2903. Write to standard output a manifest suitable for @option{--manifest}
  2904. corresponding to the chosen profile(s).
  2905. This option is meant to help you migrate from the ``imperative''
  2906. operating mode---running @command{guix install}, @command{guix upgrade},
  2907. etc.---to the declarative mode that @option{--manifest} offers.
  2908. Be aware that the resulting manifest @emph{approximates} what your
  2909. profile actually contains; for instance, depending on how your profile
  2910. was created, it can refer to packages or package versions that are not
  2911. exactly what you specified.
  2912. Keep in mind that a manifest is purely symbolic: it only contains
  2913. package names and possibly versions, and their meaning varies over time.
  2914. If you wish to ``pin'' channels to the revisions that were used to build
  2915. the profile(s), see @option{--export-channels} below.
  2916. @cindex pinning, channel revisions of a profile
  2917. @item --export-channels
  2918. Write to standard output the list of channels used by the chosen
  2919. profile(s), in a format suitable for @command{guix pull --channels} or
  2920. @command{guix time-machine --channels} (@pxref{Channels}).
  2921. Together with @option{--export-manifest}, this option provides
  2922. information allowing you to replicate the current profile
  2923. (@pxref{Replicating Guix}).
  2924. However, note that the output of this command @emph{approximates} what
  2925. was actually used to build this profile. In particular, a single
  2926. profile might have been built from several different revisions of the
  2927. same channel. In that case, @option{--export-manifest} chooses the last
  2928. one and writes the list of other revisions in a comment. If you really
  2929. need to pick packages from different channel revisions, you can use
  2930. inferiors in your manifest to do so (@pxref{Inferiors}).
  2931. Together with @option{--export-manifest}, this is a good starting point
  2932. if you are willing to migrate from the ``imperative'' model to the fully
  2933. declarative model consisting of a manifest file along with a channels
  2934. file pinning the exact channel revision(s) you want.
  2935. @end table
  2936. Finally, since @command{guix package} may actually start build
  2937. processes, it supports all the common build options (@pxref{Common Build
  2938. Options}). It also supports package transformation options, such as
  2939. @option{--with-source}, and preserves them across upgrades
  2940. (@pxref{Package Transformation Options}).
  2941. @node Substitutes
  2942. @section Substitutes
  2943. @cindex substitutes
  2944. @cindex pre-built binaries
  2945. Guix supports transparent source/binary deployment, which means that it
  2946. can either build things locally, or download pre-built items from a
  2947. server, or both. We call these pre-built items @dfn{substitutes}---they
  2948. are substitutes for local build results. In many cases, downloading a
  2949. substitute is much faster than building things locally.
  2950. Substitutes can be anything resulting from a derivation build
  2951. (@pxref{Derivations}). Of course, in the common case, they are
  2952. pre-built package binaries, but source tarballs, for instance, which
  2953. also result from derivation builds, can be available as substitutes.
  2954. @menu
  2955. * Official Substitute Server:: One particular source of substitutes.
  2956. * Substitute Server Authorization:: How to enable or disable substitutes.
  2957. * Getting Substitutes from Other Servers:: Substitute diversity.
  2958. * Substitute Authentication:: How Guix verifies substitutes.
  2959. * Proxy Settings:: How to get substitutes via proxy.
  2960. * Substitution Failure:: What happens when substitution fails.
  2961. * On Trusting Binaries:: How can you trust that binary blob?
  2962. @end menu
  2963. @node Official Substitute Server
  2964. @subsection Official Substitute Server
  2965. @cindex build farm
  2966. The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
  2967. that builds packages from Guix continuously for some
  2968. architectures, and makes them available as substitutes. This is the
  2969. default source of substitutes; it can be overridden by passing the
  2970. @option{--substitute-urls} option either to @command{guix-daemon}
  2971. (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
  2972. or to client tools such as @command{guix package}
  2973. (@pxref{client-substitute-urls,, client @option{--substitute-urls}
  2974. option}).
  2975. Substitute URLs can be either HTTP or HTTPS.
  2976. HTTPS is recommended because communications are encrypted; conversely,
  2977. using HTTP makes all communications visible to an eavesdropper, who
  2978. could use the information gathered to determine, for instance, whether
  2979. your system has unpatched security vulnerabilities.
  2980. Substitutes from the official build farm are enabled by default when
  2981. using Guix System (@pxref{GNU Distribution}). However,
  2982. they are disabled by default when using Guix on a foreign distribution,
  2983. unless you have explicitly enabled them via one of the recommended
  2984. installation steps (@pxref{Installation}). The following paragraphs
  2985. describe how to enable or disable substitutes for the official build
  2986. farm; the same procedure can also be used to enable substitutes for any
  2987. other substitute server.
  2988. @node Substitute Server Authorization
  2989. @subsection Substitute Server Authorization
  2990. @cindex security
  2991. @cindex substitutes, authorization thereof
  2992. @cindex access control list (ACL), for substitutes
  2993. @cindex ACL (access control list), for substitutes
  2994. To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
  2995. mirror thereof, you
  2996. must add its public key to the access control list (ACL) of archive
  2997. imports, using the @command{guix archive} command (@pxref{Invoking guix
  2998. archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
  2999. be compromised and to serve genuine substitutes.
  3000. @quotation Note
  3001. If you are using Guix System, you can skip this section: Guix System
  3002. authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
  3003. @end quotation
  3004. The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
  3005. @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
  3006. the installation prefix of Guix. If you installed Guix from source,
  3007. make sure you checked the GPG signature of
  3008. @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
  3009. Then, you can run something like this:
  3010. @example
  3011. # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
  3012. @end example
  3013. Once this is in place, the output of a command like @code{guix build}
  3014. should change from something like:
  3015. @example
  3016. $ guix build emacs --dry-run
  3017. The following derivations would be built:
  3018. /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
  3019. /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
  3020. /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
  3021. /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
  3022. @dots{}
  3023. @end example
  3024. @noindent
  3025. to something like:
  3026. @example
  3027. $ guix build emacs --dry-run
  3028. 112.3 MB would be downloaded:
  3029. /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
  3030. /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
  3031. /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
  3032. /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
  3033. @dots{}
  3034. @end example
  3035. @noindent
  3036. The text changed from ``The following derivations would be built'' to
  3037. ``112.3 MB would be downloaded''. This indicates that substitutes from
  3038. @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
  3039. possible, for future builds.
  3040. @cindex substitutes, how to disable
  3041. The substitute mechanism can be disabled globally by running
  3042. @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
  3043. guix-daemon}). It can also be disabled temporarily by passing the
  3044. @option{--no-substitutes} option to @command{guix package},
  3045. @command{guix build}, and other command-line tools.
  3046. @node Getting Substitutes from Other Servers
  3047. @subsection Getting Substitutes from Other Servers
  3048. @cindex substitute servers, adding more
  3049. Guix can look up and fetch substitutes from several servers. This is
  3050. useful when you are using packages from additional channels for which
  3051. the official server does not have substitutes but another server
  3052. provides them. Another situation where this is useful is when you would
  3053. prefer to download from your organization's substitute server, resorting
  3054. to the official server only as a fallback or dismissing it altogether.
  3055. You can give Guix a list of substitute server URLs and it will check
  3056. them in the specified order. You also need to explicitly authorize the
  3057. public keys of substitute servers to instruct Guix to accept the
  3058. substitutes they sign.
  3059. On Guix System, this is achieved by modifying the configuration of the
  3060. @code{guix} service. Since the @code{guix} service is part of the
  3061. default lists of services, @code{%base-services} and
  3062. @code{%desktop-services}, you can use @code{modify-services} to change
  3063. its configuration and add the URLs and substitute keys that you want
  3064. (@pxref{Service Reference, @code{modify-services}}).
  3065. As an example, suppose you want to fetch substitutes from
  3066. @code{guix.example.org} and to authorize the signing key of that server,
  3067. in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
  3068. resulting operating system configuration will look something like:
  3069. @lisp
  3070. (operating-system
  3071. ;; @dots{}
  3072. (services
  3073. ;; Assume we're starting from '%desktop-services'. Replace it
  3074. ;; with the list of services you're actually using.
  3075. (modify-services %desktop-services
  3076. (guix-service-type config =>
  3077. (guix-configuration
  3078. (inherit config)
  3079. (substitute-urls
  3080. (append (list "https://guix.example.org")
  3081. %default-substitute-urls))
  3082. (authorized-keys
  3083. (append (list (local-file "./key.pub"))
  3084. %default-authorized-guix-keys)))))))
  3085. @end lisp
  3086. This assumes that the file @file{key.pub} contains the signing key of
  3087. @code{guix.example.org}. With this change in place in your operating
  3088. system configuration file (say @file{/etc/config.scm}), you can
  3089. reconfigure and restart the @code{guix-daemon} service or reboot so the
  3090. changes take effect:
  3091. @example
  3092. $ sudo guix system reconfigure /etc/config.scm
  3093. $ sudo herd restart guix-daemon
  3094. @end example
  3095. If you're running Guix on a ``foreign distro'', you would instead take
  3096. the following steps to get substitutes from additional servers:
  3097. @enumerate
  3098. @item
  3099. Edit the service configuration file for @code{guix-daemon}; when using
  3100. systemd, this is normally
  3101. @file{/etc/systemd/system/guix-daemon.service}. Add the
  3102. @option{--substitute-urls} option on the @command{guix-daemon} command
  3103. line and list the URLs of interest (@pxref{daemon-substitute-urls,
  3104. @code{guix-daemon --substitute-urls}}):
  3105. @example
  3106. @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
  3107. @end example
  3108. @item
  3109. Restart the daemon. For systemd, it goes like this:
  3110. @example
  3111. systemctl daemon-reload
  3112. systemctl restart guix-daemon.service
  3113. @end example
  3114. @item
  3115. Authorize the key of the new server (@pxref{Invoking guix archive}):
  3116. @example
  3117. guix archive --authorize < key.pub
  3118. @end example
  3119. Again this assumes @file{key.pub} contains the public key that
  3120. @code{guix.example.org} uses to sign substitutes.
  3121. @end enumerate
  3122. Now you're all set! Substitutes will be preferably taken from
  3123. @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
  3124. as a fallback. Of course you can list as many substitute servers as you
  3125. like, with the caveat that substitute lookup can be slowed down if too
  3126. many servers need to be contacted.
  3127. Note that there are also situations where one may want to add the URL of
  3128. a substitute server @emph{without} authorizing its key.
  3129. @xref{Substitute Authentication}, to understand this fine point.
  3130. @node Substitute Authentication
  3131. @subsection Substitute Authentication
  3132. @cindex digital signatures
  3133. Guix detects and raises an error when attempting to use a substitute
  3134. that has been tampered with. Likewise, it ignores substitutes that are
  3135. not signed, or that are not signed by one of the keys listed in the ACL.
  3136. There is one exception though: if an unauthorized server provides
  3137. substitutes that are @emph{bit-for-bit identical} to those provided by
  3138. an authorized server, then the unauthorized server becomes eligible for
  3139. downloads. For example, assume we have chosen two substitute servers
  3140. with this option:
  3141. @example
  3142. --substitute-urls="https://a.example.org https://b.example.org"
  3143. @end example
  3144. @noindent
  3145. @cindex reproducible builds
  3146. If the ACL contains only the key for @samp{b.example.org}, and if
  3147. @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
  3148. then Guix will download substitutes from @samp{a.example.org} because it
  3149. comes first in the list and can be considered a mirror of
  3150. @samp{b.example.org}. In practice, independent build machines usually
  3151. produce the same binaries, thanks to bit-reproducible builds (see
  3152. below).
  3153. When using HTTPS, the server's X.509 certificate is @emph{not} validated
  3154. (in other words, the server is not authenticated), contrary to what
  3155. HTTPS clients such as Web browsers usually do. This is because Guix
  3156. authenticates substitute information itself, as explained above, which
  3157. is what we care about (whereas X.509 certificates are about
  3158. authenticating bindings between domain names and public keys).
  3159. @node Proxy Settings
  3160. @subsection Proxy Settings
  3161. @vindex http_proxy
  3162. @vindex https_proxy
  3163. Substitutes are downloaded over HTTP or HTTPS@. The @env{http_proxy} and
  3164. @env{https_proxy} environment variables can be set in the environment of
  3165. @command{guix-daemon} and are honored for downloads of substitutes.
  3166. Note that the value of those environment variables in the environment
  3167. where @command{guix build}, @command{guix package}, and other client
  3168. commands are run has @emph{absolutely no effect}.
  3169. @node Substitution Failure
  3170. @subsection Substitution Failure
  3171. Even when a substitute for a derivation is available, sometimes the
  3172. substitution attempt will fail. This can happen for a variety of
  3173. reasons: the substitute server might be offline, the substitute may
  3174. recently have been deleted, the connection might have been interrupted,
  3175. etc.
  3176. When substitutes are enabled and a substitute for a derivation is
  3177. available, but the substitution attempt fails, Guix will attempt to
  3178. build the derivation locally depending on whether or not
  3179. @option{--fallback} was given (@pxref{fallback-option,, common build
  3180. option @option{--fallback}}). Specifically, if @option{--fallback} was
  3181. omitted, then no local build will be performed, and the derivation is
  3182. considered to have failed. However, if @option{--fallback} was given,
  3183. then Guix will attempt to build the derivation locally, and the success
  3184. or failure of the derivation depends on the success or failure of the
  3185. local build. Note that when substitutes are disabled or no substitute
  3186. is available for the derivation in question, a local build will
  3187. @emph{always} be performed, regardless of whether or not
  3188. @option{--fallback} was given.
  3189. To get an idea of how many substitutes are available right now, you can
  3190. try running the @command{guix weather} command (@pxref{Invoking guix
  3191. weather}). This command provides statistics on the substitutes provided
  3192. by a server.
  3193. @node On Trusting Binaries
  3194. @subsection On Trusting Binaries
  3195. @cindex trust, of pre-built binaries
  3196. Today, each individual's control over their own computing is at the
  3197. mercy of institutions, corporations, and groups with enough power and
  3198. determination to subvert the computing infrastructure and exploit its
  3199. weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
  3200. convenient, we encourage users to also build on their own, or even run
  3201. their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
  3202. interesting target. One way to help is by publishing the software you
  3203. build using @command{guix publish} so that others have one more choice
  3204. of server to download substitutes from (@pxref{Invoking guix publish}).
  3205. Guix has the foundations to maximize build reproducibility
  3206. (@pxref{Features}). In most cases, independent builds of a given
  3207. package or derivation should yield bit-identical results. Thus, through
  3208. a diverse set of independent package builds, we can strengthen the
  3209. integrity of our systems. The @command{guix challenge} command aims to
  3210. help users assess substitute servers, and to assist developers in
  3211. finding out about non-deterministic package builds (@pxref{Invoking guix
  3212. challenge}). Similarly, the @option{--check} option of @command{guix
  3213. build} allows users to check whether previously-installed substitutes
  3214. are genuine by rebuilding them locally (@pxref{build-check,
  3215. @command{guix build --check}}).
  3216. In the future, we want Guix to have support to publish and retrieve
  3217. binaries to/from other users, in a peer-to-peer fashion. If you would
  3218. like to discuss this project, join us on @email{guix-devel@@gnu.org}.
  3219. @node Packages with Multiple Outputs
  3220. @section Packages with Multiple Outputs
  3221. @cindex multiple-output packages
  3222. @cindex package outputs
  3223. @cindex outputs
  3224. Often, packages defined in Guix have a single @dfn{output}---i.e., the
  3225. source package leads to exactly one directory in the store. When running
  3226. @command{guix install glibc}, one installs the default output of the
  3227. GNU libc package; the default output is called @code{out}, but its name
  3228. can be omitted as shown in this command. In this particular case, the
  3229. default output of @code{glibc} contains all the C header files, shared
  3230. libraries, static libraries, Info documentation, and other supporting
  3231. files.
  3232. Sometimes it is more appropriate to separate the various types of files
  3233. produced from a single source package into separate outputs. For
  3234. instance, the GLib C library (used by GTK+ and related packages)
  3235. installs more than 20 MiB of reference documentation as HTML pages.
  3236. To save space for users who do not need it, the documentation goes to a
  3237. separate output, called @code{doc}. To install the main GLib output,
  3238. which contains everything but the documentation, one would run:
  3239. @example
  3240. guix install glib
  3241. @end example
  3242. @cindex documentation
  3243. The command to install its documentation is:
  3244. @example
  3245. guix install glib:doc
  3246. @end example
  3247. Some packages install programs with different ``dependency footprints''.
  3248. For instance, the WordNet package installs both command-line tools and
  3249. graphical user interfaces (GUIs). The former depend solely on the C
  3250. library, whereas the latter depend on Tcl/Tk and the underlying X
  3251. libraries. In this case, we leave the command-line tools in the default
  3252. output, whereas the GUIs are in a separate output. This allows users
  3253. who do not need the GUIs to save space. The @command{guix size} command
  3254. can help find out about such situations (@pxref{Invoking guix size}).
  3255. @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
  3256. There are several such multiple-output packages in the GNU distribution.
  3257. Other conventional output names include @code{lib} for libraries and
  3258. possibly header files, @code{bin} for stand-alone programs, and
  3259. @code{debug} for debugging information (@pxref{Installing Debugging
  3260. Files}). The outputs of a packages are listed in the third column of
  3261. the output of @command{guix package --list-available} (@pxref{Invoking
  3262. guix package}).
  3263. @node Invoking guix gc
  3264. @section Invoking @command{guix gc}
  3265. @cindex garbage collector
  3266. @cindex disk space
  3267. Packages that are installed, but not used, may be @dfn{garbage-collected}.
  3268. The @command{guix gc} command allows users to explicitly run the garbage
  3269. collector to reclaim space from the @file{/gnu/store} directory. It is
  3270. the @emph{only} way to remove files from @file{/gnu/store}---removing
  3271. files or directories manually may break it beyond repair!
  3272. @cindex GC roots
  3273. @cindex garbage collector roots
  3274. The garbage collector has a set of known @dfn{roots}: any file under
  3275. @file{/gnu/store} reachable from a root is considered @dfn{live} and
  3276. cannot be deleted; any other file is considered @dfn{dead} and may be
  3277. deleted. The set of garbage collector roots (``GC roots'' for short)
  3278. includes default user profiles; by default, the symlinks under
  3279. @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
  3280. added with @command{guix build --root}, for example (@pxref{Invoking
  3281. guix build}). The @command{guix gc --list-roots} command lists them.
  3282. Prior to running @code{guix gc --collect-garbage} to make space, it is
  3283. often useful to remove old generations from user profiles; that way, old
  3284. package builds referenced by those generations can be reclaimed. This
  3285. is achieved by running @code{guix package --delete-generations}
  3286. (@pxref{Invoking guix package}).
  3287. Our recommendation is to run a garbage collection periodically, or when
  3288. you are short on disk space. For instance, to guarantee that at least
  3289. 5@tie{}GB are available on your disk, simply run:
  3290. @example
  3291. guix gc -F 5G
  3292. @end example
  3293. It is perfectly safe to run as a non-interactive periodic job
  3294. (@pxref{Scheduled Job Execution}, for how to set up such a job).
  3295. Running @command{guix gc} with no arguments will collect as
  3296. much garbage as it can, but that is often inconvenient: you may find
  3297. yourself having to rebuild or re-download software that is ``dead'' from
  3298. the GC viewpoint but that is necessary to build other pieces of
  3299. software---e.g., the compiler tool chain.
  3300. The @command{guix gc} command has three modes of operation: it can be
  3301. used to garbage-collect any dead files (the default), to delete specific
  3302. files (the @option{--delete} option), to print garbage-collector
  3303. information, or for more advanced queries. The garbage collection
  3304. options are as follows:
  3305. @table @code
  3306. @item --collect-garbage[=@var{min}]
  3307. @itemx -C [@var{min}]
  3308. Collect garbage---i.e., unreachable @file{/gnu/store} files and
  3309. sub-directories. This is the default operation when no option is
  3310. specified.
  3311. When @var{min} is given, stop once @var{min} bytes have been collected.
  3312. @var{min} may be a number of bytes, or it may include a unit as a
  3313. suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
  3314. (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
  3315. When @var{min} is omitted, collect all the garbage.
  3316. @item --free-space=@var{free}
  3317. @itemx -F @var{free}
  3318. Collect garbage until @var{free} space is available under
  3319. @file{/gnu/store}, if possible; @var{free} denotes storage space, such
  3320. as @code{500MiB}, as described above.
  3321. When @var{free} or more is already available in @file{/gnu/store}, do
  3322. nothing and exit immediately.
  3323. @item --delete-generations[=@var{duration}]
  3324. @itemx -d [@var{duration}]
  3325. Before starting the garbage collection process, delete all the generations
  3326. older than @var{duration}, for all the user profiles; when run as root, this
  3327. applies to all the profiles @emph{of all the users}.
  3328. For example, this command deletes all the generations of all your profiles
  3329. that are older than 2 months (except generations that are current), and then
  3330. proceeds to free space until at least 10 GiB are available:
  3331. @example
  3332. guix gc -d 2m -F 10G
  3333. @end example
  3334. @item --delete
  3335. @itemx -D
  3336. Attempt to delete all the store files and directories specified as
  3337. arguments. This fails if some of the files are not in the store, or if
  3338. they are still live.
  3339. @item --list-failures
  3340. List store items corresponding to cached build failures.
  3341. This prints nothing unless the daemon was started with
  3342. @option{--cache-failures} (@pxref{Invoking guix-daemon,
  3343. @option{--cache-failures}}).
  3344. @item --list-roots
  3345. List the GC roots owned by the user; when run as root, list @emph{all} the GC
  3346. roots.
  3347. @item --list-busy
  3348. List store items in use by currently running processes. These store
  3349. items are effectively considered GC roots: they cannot be deleted.
  3350. @item --clear-failures
  3351. Remove the specified store items from the failed-build cache.
  3352. Again, this option only makes sense when the daemon is started with
  3353. @option{--cache-failures}. Otherwise, it does nothing.
  3354. @item --list-dead
  3355. Show the list of dead files and directories still present in the
  3356. store---i.e., files and directories no longer reachable from any root.
  3357. @item --list-live
  3358. Show the list of live store files and directories.
  3359. @end table
  3360. In addition, the references among existing store files can be queried:
  3361. @table @code
  3362. @item --references
  3363. @itemx --referrers
  3364. @cindex package dependencies
  3365. List the references (respectively, the referrers) of store files given
  3366. as arguments.
  3367. @item --requisites
  3368. @itemx -R
  3369. @cindex closure
  3370. List the requisites of the store files passed as arguments. Requisites
  3371. include the store files themselves, their references, and the references
  3372. of these, recursively. In other words, the returned list is the
  3373. @dfn{transitive closure} of the store files.
  3374. @xref{Invoking guix size}, for a tool to profile the size of the closure
  3375. of an element. @xref{Invoking guix graph}, for a tool to visualize
  3376. the graph of references.
  3377. @item --derivers
  3378. @cindex derivation
  3379. Return the derivation(s) leading to the given store items
  3380. (@pxref{Derivations}).
  3381. For example, this command:
  3382. @example
  3383. guix gc --derivers `guix package -I ^emacs$ | cut -f4`
  3384. @end example
  3385. @noindent
  3386. returns the @file{.drv} file(s) leading to the @code{emacs} package
  3387. installed in your profile.
  3388. Note that there may be zero matching @file{.drv} files, for instance
  3389. because these files have been garbage-collected. There can also be more
  3390. than one matching @file{.drv} due to fixed-output derivations.
  3391. @end table
  3392. Lastly, the following options allow you to check the integrity of the
  3393. store and to control disk usage.
  3394. @table @option
  3395. @item --verify[=@var{options}]
  3396. @cindex integrity, of the store
  3397. @cindex integrity checking
  3398. Verify the integrity of the store.
  3399. By default, make sure that all the store items marked as valid in the
  3400. database of the daemon actually exist in @file{/gnu/store}.
  3401. When provided, @var{options} must be a comma-separated list containing one
  3402. or more of @code{contents} and @code{repair}.
  3403. When passing @option{--verify=contents}, the daemon computes the
  3404. content hash of each store item and compares it against its hash in the
  3405. database. Hash mismatches are reported as data corruptions. Because it
  3406. traverses @emph{all the files in the store}, this command can take a
  3407. long time, especially on systems with a slow disk drive.
  3408. @cindex repairing the store
  3409. @cindex corruption, recovering from
  3410. Using @option{--verify=repair} or @option{--verify=contents,repair}
  3411. causes the daemon to try to repair corrupt store items by fetching
  3412. substitutes for them (@pxref{Substitutes}). Because repairing is not
  3413. atomic, and thus potentially dangerous, it is available only to the
  3414. system administrator. A lightweight alternative, when you know exactly
  3415. which items in the store are corrupt, is @command{guix build --repair}
  3416. (@pxref{Invoking guix build}).
  3417. @item --optimize
  3418. @cindex deduplication
  3419. Optimize the store by hard-linking identical files---this is
  3420. @dfn{deduplication}.
  3421. The daemon performs deduplication after each successful build or archive
  3422. import, unless it was started with @option{--disable-deduplication}
  3423. (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
  3424. this option is primarily useful when the daemon was running with
  3425. @option{--disable-deduplication}.
  3426. @end table
  3427. @node Invoking guix pull
  3428. @section Invoking @command{guix pull}
  3429. @cindex upgrading Guix
  3430. @cindex updating Guix
  3431. @cindex @command{guix pull}
  3432. @cindex pull
  3433. @cindex security, @command{guix pull}
  3434. @cindex authenticity, of code obtained with @command{guix pull}
  3435. Packages are installed or upgraded to the latest version available in
  3436. the distribution currently available on your local machine. To update
  3437. that distribution, along with the Guix tools, you must run @command{guix
  3438. pull}: the command downloads the latest Guix source code and package
  3439. descriptions, and deploys it. Source code is downloaded from a
  3440. @uref{https://git-scm.com, Git} repository, by default the official
  3441. GNU@tie{}Guix repository, though this can be customized. @command{guix
  3442. pull} ensures that the code it downloads is @emph{authentic} by
  3443. verifying that commits are signed by Guix developers.
  3444. Specifically, @command{guix pull} downloads code from the @dfn{channels}
  3445. (@pxref{Channels}) specified by one of the followings, in this order:
  3446. @enumerate
  3447. @item
  3448. the @option{--channels} option;
  3449. @item
  3450. the user's @file{~/.config/guix/channels.scm} file;
  3451. @item
  3452. the system-wide @file{/etc/guix/channels.scm} file;
  3453. @item
  3454. the built-in default channels specified in the @code{%default-channels}
  3455. variable.
  3456. @end enumerate
  3457. On completion, @command{guix package} will use packages and package
  3458. versions from this just-retrieved copy of Guix. Not only that, but all
  3459. the Guix commands and Scheme modules will also be taken from that latest
  3460. version. New @command{guix} sub-commands added by the update also
  3461. become available.
  3462. Any user can update their Guix copy using @command{guix pull}, and the
  3463. effect is limited to the user who ran @command{guix pull}. For
  3464. instance, when user @code{root} runs @command{guix pull}, this has no
  3465. effect on the version of Guix that user @code{alice} sees, and vice
  3466. versa.
  3467. The result of running @command{guix pull} is a @dfn{profile} available
  3468. under @file{~/.config/guix/current} containing the latest Guix. Thus,
  3469. make sure to add it to the beginning of your search path so that you use
  3470. the latest version, and similarly for the Info manual
  3471. (@pxref{Documentation}):
  3472. @example
  3473. export PATH="$HOME/.config/guix/current/bin:$PATH"
  3474. export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
  3475. @end example
  3476. The @option{--list-generations} or @option{-l} option lists past generations
  3477. produced by @command{guix pull}, along with details about their provenance:
  3478. @example
  3479. $ guix pull -l
  3480. Generation 1 Jun 10 2018 00:18:18
  3481. guix 65956ad
  3482. repository URL: https://git.savannah.gnu.org/git/guix.git
  3483. branch: origin/master
  3484. commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
  3485. Generation 2 Jun 11 2018 11:02:49
  3486. guix e0cc7f6
  3487. repository URL: https://git.savannah.gnu.org/git/guix.git
  3488. branch: origin/master
  3489. commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
  3490. 2 new packages: keepalived, libnfnetlink
  3491. 6 packages upgraded: emacs-nix-mode@@2.0.4,
  3492. guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
  3493. heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
  3494. Generation 3 Jun 13 2018 23:31:07 (current)
  3495. guix 844cc1c
  3496. repository URL: https://git.savannah.gnu.org/git/guix.git
  3497. branch: origin/master
  3498. commit: 844cc1c8f394f03b404c5bb3aee086922373490c
  3499. 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
  3500. 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
  3501. @end example
  3502. @xref{Invoking guix describe, @command{guix describe}}, for other ways to
  3503. describe the current status of Guix.
  3504. This @code{~/.config/guix/current} profile works exactly like the profiles
  3505. created by @command{guix package} (@pxref{Invoking guix package}). That
  3506. is, you can list generations, roll back to the previous
  3507. generation---i.e., the previous Guix---and so on:
  3508. @example
  3509. $ guix pull --roll-back
  3510. switched from generation 3 to 2
  3511. $ guix pull --delete-generations=1
  3512. deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
  3513. @end example
  3514. You can also use @command{guix package} (@pxref{Invoking guix package})
  3515. to manage the profile by naming it explicitly:
  3516. @example
  3517. $ guix package -p ~/.config/guix/current --roll-back
  3518. switched from generation 3 to 2
  3519. $ guix package -p ~/.config/guix/current --delete-generations=1
  3520. deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
  3521. @end example
  3522. The @command{guix pull} command is usually invoked with no arguments,
  3523. but it supports the following options:
  3524. @table @code
  3525. @item --url=@var{url}
  3526. @itemx --commit=@var{commit}
  3527. @itemx --branch=@var{branch}
  3528. Download code for the @code{guix} channel from the specified @var{url}, at the
  3529. given @var{commit} (a valid Git commit ID represented as a hexadecimal
  3530. string), or @var{branch}.
  3531. @cindex @file{channels.scm}, configuration file
  3532. @cindex configuration file for channels
  3533. These options are provided for convenience, but you can also specify your
  3534. configuration in the @file{~/.config/guix/channels.scm} file or using the
  3535. @option{--channels} option (see below).
  3536. @item --channels=@var{file}
  3537. @itemx -C @var{file}
  3538. Read the list of channels from @var{file} instead of
  3539. @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
  3540. @var{file} must contain Scheme code that
  3541. evaluates to a list of channel objects. @xref{Channels}, for more
  3542. information.
  3543. @cindex channel news
  3544. @item --news
  3545. @itemx -N
  3546. Display the list of packages added or upgraded since the previous
  3547. generation, as well as, occasionally, news written by channel authors
  3548. for their users (@pxref{Channels, Writing Channel News}).
  3549. The package information is the same as displayed upon @command{guix
  3550. pull} completion, but without ellipses; it is also similar to the output
  3551. of @command{guix pull -l} for the last generation (see below).
  3552. @item --list-generations[=@var{pattern}]
  3553. @itemx -l [@var{pattern}]
  3554. List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
  3555. is provided, the subset of generations that match @var{pattern}.
  3556. The syntax of @var{pattern} is the same as with @code{guix package
  3557. --list-generations} (@pxref{Invoking guix package}).
  3558. @item --roll-back
  3559. @cindex rolling back
  3560. @cindex undoing transactions
  3561. @cindex transactions, undoing
  3562. Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
  3563. undo the last transaction.
  3564. @item --switch-generation=@var{pattern}
  3565. @itemx -S @var{pattern}
  3566. @cindex generations
  3567. Switch to a particular generation defined by @var{pattern}.
  3568. @var{pattern} may be either a generation number or a number prefixed
  3569. with ``+'' or ``-''. The latter means: move forward/backward by a
  3570. specified number of generations. For example, if you want to return to
  3571. the latest generation after @option{--roll-back}, use
  3572. @option{--switch-generation=+1}.
  3573. @item --delete-generations[=@var{pattern}]
  3574. @itemx -d [@var{pattern}]
  3575. When @var{pattern} is omitted, delete all generations except the current
  3576. one.
  3577. This command accepts the same patterns as @option{--list-generations}.
  3578. When @var{pattern} is specified, delete the matching generations. When
  3579. @var{pattern} specifies a duration, generations @emph{older} than the
  3580. specified duration match. For instance, @option{--delete-generations=1m}
  3581. deletes generations that are more than one month old.
  3582. If the current generation matches, it is @emph{not} deleted.
  3583. Note that deleting generations prevents rolling back to them.
  3584. Consequently, this command must be used with care.
  3585. @xref{Invoking guix describe}, for a way to display information about the
  3586. current generation only.
  3587. @item --profile=@var{profile}
  3588. @itemx -p @var{profile}
  3589. Use @var{profile} instead of @file{~/.config/guix/current}.
  3590. @item --dry-run
  3591. @itemx -n
  3592. Show which channel commit(s) would be used and what would be built or
  3593. substituted but do not actually do it.
  3594. @item --allow-downgrades
  3595. Allow pulling older or unrelated revisions of channels than those
  3596. currently in use.
  3597. @cindex downgrade attacks, protection against
  3598. By default, @command{guix pull} protects against so-called ``downgrade
  3599. attacks'' whereby the Git repository of a channel would be reset to an
  3600. earlier or unrelated revision of itself, potentially leading you to
  3601. install older, known-vulnerable versions of software packages.
  3602. @quotation Note
  3603. Make sure you understand its security implications before using
  3604. @option{--allow-downgrades}.
  3605. @end quotation
  3606. @item --disable-authentication
  3607. Allow pulling channel code without authenticating it.
  3608. @cindex authentication, of channel code
  3609. By default, @command{guix pull} authenticates code downloaded from
  3610. channels by verifying that its commits are signed by authorized
  3611. developers, and raises an error if this is not the case. This option
  3612. instructs it to not perform any such verification.
  3613. @quotation Note
  3614. Make sure you understand its security implications before using
  3615. @option{--disable-authentication}.
  3616. @end quotation
  3617. @item --system=@var{system}
  3618. @itemx -s @var{system}
  3619. Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
  3620. the system type of the build host.
  3621. @item --bootstrap
  3622. Use the bootstrap Guile to build the latest Guix. This option is only
  3623. useful to Guix developers.
  3624. @end table
  3625. The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
  3626. repository and branch to pull from, as well as @emph{additional} repositories
  3627. containing package modules that should be deployed. @xref{Channels}, for more
  3628. information.
  3629. In addition, @command{guix pull} supports all the common build options
  3630. (@pxref{Common Build Options}).
  3631. @node Invoking guix time-machine
  3632. @section Invoking @command{guix time-machine}
  3633. @cindex @command{guix time-machine}
  3634. @cindex pinning, channels
  3635. @cindex replicating Guix
  3636. @cindex reproducibility, of Guix
  3637. The @command{guix time-machine} command provides access to other
  3638. revisions of Guix, for example to install older versions of packages,
  3639. or to reproduce a computation in an identical environment. The revision
  3640. of Guix to be used is defined by a commit or by a channel
  3641. description file created by @command{guix describe}
  3642. (@pxref{Invoking guix describe}).
  3643. The general syntax is:
  3644. @example
  3645. guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
  3646. @end example
  3647. where @var{command} and @var{arg}@dots{} are passed unmodified to the
  3648. @command{guix} command of the specified revision. The @var{options} that define
  3649. this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
  3650. @table @code
  3651. @item --url=@var{url}
  3652. @itemx --commit=@var{commit}
  3653. @itemx --branch=@var{branch}
  3654. Use the @code{guix} channel from the specified @var{url}, at the
  3655. given @var{commit} (a valid Git commit ID represented as a hexadecimal
  3656. string), or @var{branch}.
  3657. @item --channels=@var{file}
  3658. @itemx -C @var{file}
  3659. Read the list of channels from @var{file}. @var{file} must contain
  3660. Scheme code that evaluates to a list of channel objects.
  3661. @xref{Channels} for more information.
  3662. @end table
  3663. As for @command{guix pull}, the absence of any options means that the
  3664. latest commit on the master branch will be used. The command
  3665. @example
  3666. guix time-machine -- build hello
  3667. @end example
  3668. will thus build the package @code{hello} as defined in the master branch,
  3669. which is in general a newer revision of Guix than you have installed.
  3670. Time travel works in both directions!
  3671. Note that @command{guix time-machine} can trigger builds of channels and
  3672. their dependencies, and these are controlled by the standard build
  3673. options (@pxref{Common Build Options}).
  3674. @node Inferiors
  3675. @section Inferiors
  3676. @c TODO: Remove this once we're more confident about API stability.
  3677. @quotation Note
  3678. The functionality described here is a ``technology preview'' as of version
  3679. @value{VERSION}. As such, the interface is subject to change.
  3680. @end quotation
  3681. @cindex inferiors
  3682. @cindex composition of Guix revisions
  3683. Sometimes you might need to mix packages from the revision of Guix you're
  3684. currently running with packages available in a different revision of Guix.
  3685. Guix @dfn{inferiors} allow you to achieve that by composing different Guix
  3686. revisions in arbitrary ways.
  3687. @cindex inferior packages
  3688. Technically, an ``inferior'' is essentially a separate Guix process connected
  3689. to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
  3690. @code{(guix inferior)} module allows you to create inferiors and to
  3691. communicate with them. It also provides a high-level interface to browse and
  3692. manipulate the packages that an inferior provides---@dfn{inferior packages}.
  3693. When combined with channels (@pxref{Channels}), inferiors provide a simple way
  3694. to interact with a separate revision of Guix. For example, let's assume you
  3695. want to install in your profile the current @code{guile} package, along with
  3696. the @code{guile-json} as it existed in an older revision of Guix---perhaps
  3697. because the newer @code{guile-json} has an incompatible API and you want to
  3698. run your code against the old API@. To do that, you could write a manifest for
  3699. use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
  3700. manifest, you would create an inferior for that old Guix revision you care
  3701. about, and you would look up the @code{guile-json} package in the inferior:
  3702. @lisp
  3703. (use-modules (guix inferior) (guix channels)
  3704. (srfi srfi-1)) ;for 'first'
  3705. (define channels
  3706. ;; This is the old revision from which we want to
  3707. ;; extract guile-json.
  3708. (list (channel
  3709. (name 'guix)
  3710. (url "https://git.savannah.gnu.org/git/guix.git")
  3711. (commit
  3712. "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
  3713. (define inferior
  3714. ;; An inferior representing the above revision.
  3715. (inferior-for-channels channels))
  3716. ;; Now create a manifest with the current "guile" package
  3717. ;; and the old "guile-json" package.
  3718. (packages->manifest
  3719. (list (first (lookup-inferior-packages inferior "guile-json"))
  3720. (specification->package "guile")))
  3721. @end lisp
  3722. On its first run, @command{guix package --manifest} might have to build the
  3723. channel you specified before it can create the inferior; subsequent runs will
  3724. be much faster because the Guix revision will be cached.
  3725. The @code{(guix inferior)} module provides the following procedures to open an
  3726. inferior:
  3727. @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
  3728. [#:cache-directory] [#:ttl]
  3729. Return an inferior for @var{channels}, a list of channels. Use the cache at
  3730. @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
  3731. This procedure opens a new connection to the build daemon.
  3732. As a side effect, this procedure may build or substitute binaries for
  3733. @var{channels}, which can take time.
  3734. @end deffn
  3735. @deffn {Scheme Procedure} open-inferior @var{directory} @
  3736. [#:command "bin/guix"]
  3737. Open the inferior Guix in @var{directory}, running
  3738. @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
  3739. the inferior could not be launched.
  3740. @end deffn
  3741. @cindex inferior packages
  3742. The procedures listed below allow you to obtain and manipulate inferior
  3743. packages.
  3744. @deffn {Scheme Procedure} inferior-packages @var{inferior}
  3745. Return the list of packages known to @var{inferior}.
  3746. @end deffn
  3747. @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
  3748. [@var{version}]
  3749. Return the sorted list of inferior packages matching @var{name} in
  3750. @var{inferior}, with highest version numbers first. If @var{version} is true,
  3751. return only packages with a version number prefixed by @var{version}.
  3752. @end deffn
  3753. @deffn {Scheme Procedure} inferior-package? @var{obj}
  3754. Return true if @var{obj} is an inferior package.
  3755. @end deffn
  3756. @deffn {Scheme Procedure} inferior-package-name @var{package}
  3757. @deffnx {Scheme Procedure} inferior-package-version @var{package}
  3758. @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
  3759. @deffnx {Scheme Procedure} inferior-package-description @var{package}
  3760. @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
  3761. @deffnx {Scheme Procedure} inferior-package-location @var{package}
  3762. @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
  3763. @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
  3764. @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
  3765. @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
  3766. @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
  3767. @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
  3768. @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
  3769. These procedures are the counterpart of package record accessors
  3770. (@pxref{package Reference}). Most of them work by querying the inferior
  3771. @var{package} comes from, so the inferior must still be live when you call
  3772. these procedures.
  3773. @end deffn
  3774. Inferior packages can be used transparently like any other package or
  3775. file-like object in G-expressions (@pxref{G-Expressions}). They are also
  3776. transparently handled by the @code{packages->manifest} procedure, which is
  3777. commonly use in manifests (@pxref{Invoking guix package, the
  3778. @option{--manifest} option of @command{guix package}}). Thus you can insert
  3779. an inferior package pretty much anywhere you would insert a regular package:
  3780. in manifests, in the @code{packages} field of your @code{operating-system}
  3781. declaration, and so on.
  3782. @node Invoking guix describe
  3783. @section Invoking @command{guix describe}
  3784. @cindex reproducibility
  3785. @cindex replicating Guix
  3786. Often you may want to answer questions like: ``Which revision of Guix am I
  3787. using?'' or ``Which channels am I using?'' This is useful information in many
  3788. situations: if you want to @emph{replicate} an environment on a different
  3789. machine or user account, if you want to report a bug or to determine what
  3790. change in the channels you are using caused it, or if you want to record your
  3791. system state for reproducibility purposes. The @command{guix describe}
  3792. command answers these questions.
  3793. When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
  3794. displays the channel(s) that it was built from, including their repository URL
  3795. and commit IDs (@pxref{Channels}):
  3796. @example
  3797. $ guix describe
  3798. Generation 10 Sep 03 2018 17:32:44 (current)
  3799. guix e0fa68c
  3800. repository URL: https://git.savannah.gnu.org/git/guix.git
  3801. branch: master
  3802. commit: e0fa68c7718fffd33d81af415279d6ddb518f727
  3803. @end example
  3804. If you're familiar with the Git version control system, this is similar in
  3805. spirit to @command{git describe}; the output is also similar to that of
  3806. @command{guix pull --list-generations}, but limited to the current generation
  3807. (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
  3808. the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
  3809. information is all it takes to describe the revision of Guix you're using, and
  3810. also to replicate it.
  3811. To make it easier to replicate Guix, @command{guix describe} can also be asked
  3812. to return a list of channels instead of the human-readable description above:
  3813. @example
  3814. $ guix describe -f channels
  3815. (list (channel
  3816. (name 'guix)
  3817. (url "https://git.savannah.gnu.org/git/guix.git")
  3818. (commit
  3819. "e0fa68c7718fffd33d81af415279d6ddb518f727")
  3820. (introduction
  3821. (make-channel-introduction
  3822. "9edb3f66fd807b096b48283debdcddccfea34bad"
  3823. (openpgp-fingerprint
  3824. "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
  3825. @end example
  3826. @noindent
  3827. You can save this to a file and feed it to @command{guix pull -C} on some
  3828. other machine or at a later point in time, which will instantiate @emph{this
  3829. exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
  3830. From there on, since you're able to deploy the same revision of Guix, you can
  3831. just as well @emph{replicate a complete software environment}. We humbly
  3832. think that this is @emph{awesome}, and we hope you'll like it too!
  3833. The details of the options supported by @command{guix describe} are as
  3834. follows:
  3835. @table @code
  3836. @item --format=@var{format}
  3837. @itemx -f @var{format}
  3838. Produce output in the specified @var{format}, one of:
  3839. @table @code
  3840. @item human
  3841. produce human-readable output;
  3842. @item channels
  3843. produce a list of channel specifications that can be passed to @command{guix
  3844. pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
  3845. guix pull});
  3846. @item channels-sans-intro
  3847. like @code{channels}, but omit the @code{introduction} field; use it to
  3848. produce a channel specification suitable for Guix version 1.1.0 or
  3849. earlier---the @code{introduction} field has to do with channel
  3850. authentication (@pxref{Channels, Channel Authentication}) and is not
  3851. supported by these older versions;
  3852. @item json
  3853. @cindex JSON
  3854. produce a list of channel specifications in JSON format;
  3855. @item recutils
  3856. produce a list of channel specifications in Recutils format.
  3857. @end table
  3858. @item --list-formats
  3859. Display available formats for @option{--format} option.
  3860. @item --profile=@var{profile}
  3861. @itemx -p @var{profile}
  3862. Display information about @var{profile}.
  3863. @end table
  3864. @node Invoking guix archive
  3865. @section Invoking @command{guix archive}
  3866. @cindex @command{guix archive}
  3867. @cindex archive
  3868. The @command{guix archive} command allows users to @dfn{export} files
  3869. from the store into a single archive, and to later @dfn{import} them on
  3870. a machine that runs Guix.
  3871. In particular, it allows store files to be transferred from one machine
  3872. to the store on another machine.
  3873. @quotation Note
  3874. If you're looking for a way to produce archives in a format suitable for
  3875. tools other than Guix, @pxref{Invoking guix pack}.
  3876. @end quotation
  3877. @cindex exporting store items
  3878. To export store files as an archive to standard output, run:
  3879. @example
  3880. guix archive --export @var{options} @var{specifications}...
  3881. @end example
  3882. @var{specifications} may be either store file names or package
  3883. specifications, as for @command{guix package} (@pxref{Invoking guix
  3884. package}). For instance, the following command creates an archive
  3885. containing the @code{gui} output of the @code{git} package and the main
  3886. output of @code{emacs}:
  3887. @example
  3888. guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
  3889. @end example
  3890. If the specified packages are not built yet, @command{guix archive}
  3891. automatically builds them. The build process may be controlled with the
  3892. common build options (@pxref{Common Build Options}).
  3893. To transfer the @code{emacs} package to a machine connected over SSH,
  3894. one would run:
  3895. @example
  3896. guix archive --export -r emacs | ssh the-machine guix archive --import
  3897. @end example
  3898. @noindent
  3899. Similarly, a complete user profile may be transferred from one machine
  3900. to another like this:
  3901. @example
  3902. guix archive --export -r $(readlink -f ~/.guix-profile) | \
  3903. ssh the-machine guix archive --import
  3904. @end example
  3905. @noindent
  3906. However, note that, in both examples, all of @code{emacs} and the
  3907. profile as well as all of their dependencies are transferred (due to
  3908. @option{-r}), regardless of what is already available in the store on
  3909. the target machine. The @option{--missing} option can help figure out
  3910. which items are missing from the target store. The @command{guix copy}
  3911. command simplifies and optimizes this whole process, so this is probably
  3912. what you should use in this case (@pxref{Invoking guix copy}).
  3913. @cindex nar, archive format
  3914. @cindex normalized archive (nar)
  3915. @cindex nar bundle, archive format
  3916. Each store item is written in the @dfn{normalized archive} or @dfn{nar}
  3917. format (described below), and the output of @command{guix archive
  3918. --export} (and input of @command{guix archive --import}) is a @dfn{nar
  3919. bundle}.
  3920. The nar format is
  3921. comparable in spirit to `tar', but with differences
  3922. that make it more appropriate for our purposes. First, rather than
  3923. recording all Unix metadata for each file, the nar format only mentions
  3924. the file type (regular, directory, or symbolic link); Unix permissions
  3925. and owner/group are dismissed. Second, the order in which directory
  3926. entries are stored always follows the order of file names according to
  3927. the C locale collation order. This makes archive production fully
  3928. deterministic.
  3929. That nar bundle format is essentially the concatenation of zero or more
  3930. nars along with metadata for each store item it contains: its file name,
  3931. references, corresponding derivation, and a digital signature.
  3932. When exporting, the daemon digitally signs the contents of the archive,
  3933. and that digital signature is appended. When importing, the daemon
  3934. verifies the signature and rejects the import in case of an invalid
  3935. signature or if the signing key is not authorized.
  3936. @c FIXME: Add xref to daemon doc about signatures.
  3937. The main options are:
  3938. @table @code
  3939. @item --export
  3940. Export the specified store files or packages (see below). Write the
  3941. resulting archive to the standard output.
  3942. Dependencies are @emph{not} included in the output, unless
  3943. @option{--recursive} is passed.
  3944. @item -r
  3945. @itemx --recursive
  3946. When combined with @option{--export}, this instructs @command{guix archive}
  3947. to include dependencies of the given items in the archive. Thus, the
  3948. resulting archive is self-contained: it contains the closure of the
  3949. exported store items.
  3950. @item --import
  3951. Read an archive from the standard input, and import the files listed
  3952. therein into the store. Abort if the archive has an invalid digital
  3953. signature, or if it is signed by a public key not among the authorized
  3954. keys (see @option{--authorize} below).
  3955. @item --missing
  3956. Read a list of store file names from the standard input, one per line,
  3957. and write on the standard output the subset of these files missing from
  3958. the store.
  3959. @item --generate-key[=@var{parameters}]
  3960. @cindex signing, archives
  3961. Generate a new key pair for the daemon. This is a prerequisite before
  3962. archives can be exported with @option{--export}. This
  3963. operation is usually instantaneous but it can take time if the system's
  3964. entropy pool needs to be refilled. On Guix System,
  3965. @code{guix-service-type} takes care of generating this key pair the
  3966. first boot.
  3967. The generated key pair is typically stored under @file{/etc/guix}, in
  3968. @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
  3969. key, which must be kept secret). When @var{parameters} is omitted,
  3970. an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
  3971. versions before 1.6.0, it is a 4096-bit RSA key.
  3972. Alternatively, @var{parameters} can specify
  3973. @code{genkey} parameters suitable for Libgcrypt (@pxref{General
  3974. public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
  3975. Libgcrypt Reference Manual}).
  3976. @item --authorize
  3977. @cindex authorizing, archives
  3978. Authorize imports signed by the public key passed on standard input.
  3979. The public key must be in ``s-expression advanced format''---i.e., the
  3980. same format as the @file{signing-key.pub} file.
  3981. The list of authorized keys is kept in the human-editable file
  3982. @file{/etc/guix/acl}. The file contains
  3983. @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
  3984. s-expressions''} and is structured as an access-control list in the
  3985. @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
  3986. (SPKI)}.
  3987. @item --extract=@var{directory}
  3988. @itemx -x @var{directory}
  3989. Read a single-item archive as served by substitute servers
  3990. (@pxref{Substitutes}) and extract it to @var{directory}. This is a
  3991. low-level operation needed in only very narrow use cases; see below.
  3992. For example, the following command extracts the substitute for Emacs
  3993. served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
  3994. @example
  3995. $ wget -O - \
  3996. https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
  3997. | gunzip | guix archive -x /tmp/emacs
  3998. @end example
  3999. Single-item archives are different from multiple-item archives produced
  4000. by @command{guix archive --export}; they contain a single store item,
  4001. and they do @emph{not} embed a signature. Thus this operation does
  4002. @emph{no} signature verification and its output should be considered
  4003. unsafe.
  4004. The primary purpose of this operation is to facilitate inspection of
  4005. archive contents coming from possibly untrusted substitute servers
  4006. (@pxref{Invoking guix challenge}).
  4007. @item --list
  4008. @itemx -t
  4009. Read a single-item archive as served by substitute servers
  4010. (@pxref{Substitutes}) and print the list of files it contains, as in
  4011. this example:
  4012. @example
  4013. $ wget -O - \
  4014. https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
  4015. | lzip -d | guix archive -t
  4016. @end example
  4017. @end table
  4018. @c *********************************************************************
  4019. @node Channels
  4020. @chapter Channels
  4021. @cindex channels
  4022. @cindex @file{channels.scm}, configuration file
  4023. @cindex configuration file for channels
  4024. @cindex @command{guix pull}, configuration file
  4025. @cindex configuration of @command{guix pull}
  4026. Guix and its package collection are updated by running @command{guix pull}
  4027. (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
  4028. deploys Guix itself from the official GNU@tie{}Guix repository. This can be
  4029. customized by defining @dfn{channels} in the
  4030. @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
  4031. of a Git repository to be deployed, and @command{guix pull} can be instructed
  4032. to pull from one or more channels. In other words, channels can be used
  4033. to @emph{customize} and to @emph{extend} Guix, as we will see below.
  4034. Guix is able to take into account security concerns and deal with authenticated
  4035. updates.
  4036. @menu
  4037. * Specifying Additional Channels:: Extending the package collection.
  4038. * Using a Custom Guix Channel:: Using a customized Guix.
  4039. * Replicating Guix:: Running the @emph{exact same} Guix.
  4040. * Channel Authentication:: How Guix verifies what it fetches.
  4041. * Creating a Channel:: How to write your custom channel.
  4042. * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
  4043. * Declaring Channel Dependencies:: How to depend on other channels.
  4044. * Specifying Channel Authorizations:: Defining channel authors authorizations.
  4045. * Primary URL:: Distinguishing mirror to original.
  4046. * Writing Channel News:: Communicating information to channel's users.
  4047. * Channels with Substitutes:: Using channels with available substitutes.
  4048. @end menu
  4049. @node Specifying Additional Channels
  4050. @section Specifying Additional Channels
  4051. @cindex extending the package collection (channels)
  4052. @cindex variant packages (channels)
  4053. You can specify @emph{additional channels} to pull from. To use a channel, write
  4054. @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
  4055. @emph{in addition} to the default Guix channel(s):
  4056. @vindex %default-channels
  4057. @lisp
  4058. ;; Add variant packages to those Guix provides.
  4059. (cons (channel
  4060. (name 'variant-packages)
  4061. (url "https://example.org/variant-packages.git"))
  4062. %default-channels)
  4063. @end lisp
  4064. @noindent
  4065. Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
  4066. add a channel the list of channels that the variable @code{%default-channels}
  4067. is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
  4068. Manual}). With this file in place, @command{guix pull} builds not only Guix
  4069. but also the package modules from your own repository. The result in
  4070. @file{~/.config/guix/current} is the union of Guix with your own package
  4071. modules:
  4072. @example
  4073. $ guix pull --list-generations
  4074. @dots{}
  4075. Generation 19 Aug 27 2018 16:20:48
  4076. guix d894ab8
  4077. repository URL: https://git.savannah.gnu.org/git/guix.git
  4078. branch: master
  4079. commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
  4080. variant-packages dd3df5e
  4081. repository URL: https://example.org/variant-packages.git
  4082. branch: master
  4083. commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
  4084. 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
  4085. 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
  4086. @end example
  4087. @noindent
  4088. The output of @command{guix pull} above shows that Generation@tie{}19 includes
  4089. both Guix and packages from the @code{variant-personal-packages} channel. Among
  4090. the new and upgraded packages that are listed, some like @code{variant-gimp} and
  4091. @code{variant-emacs-with-cool-features} might come from
  4092. @code{variant-packages}, while others come from the Guix default channel.
  4093. @node Using a Custom Guix Channel
  4094. @section Using a Custom Guix Channel
  4095. The channel called @code{guix} specifies where Guix itself---its command-line
  4096. tools as well as its package collection---should be downloaded. For instance,
  4097. suppose you want to update from another copy of the Guix repository at
  4098. @code{example.org}, and specifically the @code{super-hacks} branch, you can
  4099. write in @code{~/.config/guix/channels.scm} this specification:
  4100. @lisp
  4101. ;; Tell 'guix pull' to use another repo.
  4102. (list (channel
  4103. (name 'guix)
  4104. (url "https://example.org/another-guix.git")
  4105. (branch "super-hacks")))
  4106. @end lisp
  4107. @noindent
  4108. From there on, @command{guix pull} will fetch code from the @code{super-hacks}
  4109. branch of the repository at @code{example.org}. The authentication concern is
  4110. addressed below ((@pxref{Channel Authentication}).
  4111. @node Replicating Guix
  4112. @section Replicating Guix
  4113. @cindex pinning, channels
  4114. @cindex replicating Guix
  4115. @cindex reproducibility, of Guix
  4116. The @command{guix pull --list-generations} output above shows precisely which
  4117. commits were used to build this instance of Guix. We can thus replicate it,
  4118. say, on another machine, by providing a channel specification in
  4119. @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
  4120. @lisp
  4121. ;; Deploy specific commits of my channels of interest.
  4122. (list (channel
  4123. (name 'guix)
  4124. (url "https://git.savannah.gnu.org/git/guix.git")
  4125. (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
  4126. (channel
  4127. (name 'variant-packages)
  4128. (url "https://example.org/variant-packages.git")
  4129. (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
  4130. @end lisp
  4131. The @command{guix describe --format=channels} command can even generate this
  4132. list of channels directly (@pxref{Invoking guix describe}). The resulting
  4133. file can be used with the -C options of @command{guix pull}
  4134. (@pxref{Invoking guix pull}) or @command{guix time-machine}
  4135. (@pxref{Invoking guix time-machine}).
  4136. At this point the two machines run the @emph{exact same Guix}, with access to
  4137. the @emph{exact same packages}. The output of @command{guix build gimp} on
  4138. one machine will be exactly the same, bit for bit, as the output of the same
  4139. command on the other machine. It also means both machines have access to all
  4140. the source code of Guix and, transitively, to all the source code of every
  4141. package it defines.
  4142. This gives you super powers, allowing you to track the provenance of binary
  4143. artifacts with very fine grain, and to reproduce software environments at
  4144. will---some sort of ``meta reproducibility'' capabilities, if you will.
  4145. @xref{Inferiors}, for another way to take advantage of these super powers.
  4146. @node Channel Authentication
  4147. @section Channel Authentication
  4148. @anchor{channel-authentication}
  4149. @cindex authentication, of channel code
  4150. The @command{guix pull} and @command{guix time-machine} commands
  4151. @dfn{authenticate} the code retrieved from channels: they make sure each
  4152. commit that is fetched is signed by an authorized developer. The goal
  4153. is to protect from unauthorized modifications to the channel that would
  4154. lead users to run malicious code.
  4155. As a user, you must provide a @dfn{channel introduction} in your
  4156. channels file so that Guix knows how to authenticate its first commit.
  4157. A channel specification, including its introduction, looks something
  4158. along these lines:
  4159. @lisp
  4160. (channel
  4161. (name 'some-channel)
  4162. (url "https://example.org/some-channel.git")
  4163. (introduction
  4164. (make-channel-introduction
  4165. "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
  4166. (openpgp-fingerprint
  4167. "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
  4168. @end lisp
  4169. The specification above shows the name and URL of the channel. The call
  4170. to @code{make-channel-introduction} above specifies that authentication
  4171. of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
  4172. by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
  4173. For the main channel, called @code{guix}, you automatically get that
  4174. information from your Guix installation. For other channels, include
  4175. the channel introduction provided by the channel authors in your
  4176. @file{channels.scm} file. Make sure you retrieve the channel
  4177. introduction from a trusted source since that is the root of your trust.
  4178. If you're curious about the authentication mechanics, read on!
  4179. @node Creating a Channel
  4180. @section Creating a Channel
  4181. @cindex personal packages (channels)
  4182. @cindex channels, for personal packages
  4183. Let's say you have a bunch of custom package variants or personal packages
  4184. that you think would make little sense to contribute to the Guix project, but
  4185. would like to have these packages transparently available to you at the
  4186. command line. You would first write modules containing those package
  4187. definitions (@pxref{Package Modules}), maintain them in a Git repository, and
  4188. then you and anyone else can use it as an additional channel to get packages
  4189. from. Neat, no?
  4190. @c What follows stems from discussions at
  4191. @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
  4192. @c earlier discussions on guix-devel@gnu.org.
  4193. @quotation Warning
  4194. Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
  4195. publish your personal channel to the world, we would like to share a few words
  4196. of caution:
  4197. @itemize
  4198. @item
  4199. Before publishing a channel, please consider contributing your package
  4200. definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
  4201. to free software of all sorts, and packages in Guix proper are readily
  4202. available to all Guix users and benefit from the project's quality assurance
  4203. process.
  4204. @item
  4205. When you maintain package definitions outside Guix, we, Guix developers,
  4206. consider that @emph{the compatibility burden is on you}. Remember that
  4207. package modules and package definitions are just Scheme code that uses various
  4208. programming interfaces (APIs). We want to remain free to change these APIs to
  4209. keep improving Guix, possibly in ways that break your channel. We never
  4210. change APIs gratuitously, but we will @emph{not} commit to freezing APIs
  4211. either.
  4212. @item
  4213. Corollary: if you're using an external channel and that channel breaks, please
  4214. @emph{report the issue to the channel authors}, not to the Guix project.
  4215. @end itemize
  4216. You've been warned! Having said this, we believe external channels are a
  4217. practical way to exert your freedom to augment Guix' package collection and to
  4218. share your improvements, which are basic tenets of
  4219. @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
  4220. email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
  4221. @end quotation
  4222. To create a channel, create a Git repository containing your own package
  4223. modules and make it available. The repository can contain anything, but a
  4224. useful channel will contain Guile modules that export packages. Once you
  4225. start using a channel, Guix will behave as if the root directory of that
  4226. channel's Git repository has been added to the Guile load path (@pxref{Load
  4227. Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
  4228. contains a file at @file{my-packages/my-tools.scm} that defines a Guile
  4229. module, then the module will be available under the name @code{(my-packages
  4230. my-tools)}, and you will be able to use it like any other module
  4231. (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
  4232. As a channel author, consider bundling authentication material with your
  4233. channel so that users can authenticate it. @xref{Channel
  4234. Authentication}, and @ref{Specifying Channel Authorizations}, for info
  4235. on how to do it.
  4236. @node Package Modules in a Sub-directory
  4237. @section Package Modules in a Sub-directory
  4238. @cindex subdirectory, channels
  4239. As a channel author, you may want to keep your channel modules in a
  4240. sub-directory. If your modules are in the sub-directory @file{guix}, you must
  4241. add a meta-data file @file{.guix-channel} that contains:
  4242. @lisp
  4243. (channel
  4244. (version 0)
  4245. (directory "guix"))
  4246. @end lisp
  4247. @node Declaring Channel Dependencies
  4248. @section Declaring Channel Dependencies
  4249. @cindex dependencies, channels
  4250. @cindex meta-data, channels
  4251. Channel authors may decide to augment a package collection provided by other
  4252. channels. They can declare their channel to be dependent on other channels in
  4253. a meta-data file @file{.guix-channel}, which is to be placed in the root of
  4254. the channel repository.
  4255. The meta-data file should contain a simple S-expression like this:
  4256. @lisp
  4257. (channel
  4258. (version 0)
  4259. (dependencies
  4260. (channel
  4261. (name some-collection)
  4262. (url "https://example.org/first-collection.git")
  4263. ;; The 'introduction' bit below is optional: you would
  4264. ;; provide it for dependencies that can be authenticated.
  4265. (introduction
  4266. (channel-introduction
  4267. (version 0)
  4268. (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
  4269. (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
  4270. (channel
  4271. (name some-other-collection)
  4272. (url "https://example.org/second-collection.git")
  4273. (branch "testing"))))
  4274. @end lisp
  4275. In the above example this channel is declared to depend on two other channels,
  4276. which will both be fetched automatically. The modules provided by the channel
  4277. will be compiled in an environment where the modules of all these declared
  4278. channels are available.
  4279. For the sake of reliability and maintainability, you should avoid dependencies
  4280. on channels that you don't control, and you should aim to keep the number of
  4281. dependencies to a minimum.
  4282. @node Specifying Channel Authorizations
  4283. @section Specifying Channel Authorizations
  4284. @cindex channel authorizations
  4285. @anchor{channel-authorizations}
  4286. As we saw above, Guix ensures the source code it pulls from channels
  4287. comes from authorized developers. As a channel author, you need to
  4288. specify the list of authorized developers in the
  4289. @file{.guix-authorizations} file in the channel's Git repository. The
  4290. authentication rule is simple: each commit must be signed by a key
  4291. listed in the @file{.guix-authorizations} file of its parent
  4292. commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
  4293. (DAG). Each commit can have zero or more parents; ``regular'' commits
  4294. have one parent and merge commits have two parent commits. Read
  4295. @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
  4296. for Computer Scientists}} for a great overview.} The
  4297. @file{.guix-authorizations} file looks like this:
  4298. @lisp
  4299. ;; Example '.guix-authorizations' file.
  4300. (authorizations
  4301. (version 0) ;current file format version
  4302. (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
  4303. (name "alice"))
  4304. ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
  4305. (name "bob"))
  4306. ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
  4307. (name "charlie"))))
  4308. @end lisp
  4309. Each fingerprint is followed by optional key/value pairs, as in the
  4310. example above. Currently these key/value pairs are ignored.
  4311. This authentication rule creates a chicken-and-egg issue: how do we
  4312. authenticate the first commit? Related to that: how do we deal with
  4313. channels whose repository history contains unsigned commits and lack
  4314. @file{.guix-authorizations}? And how do we fork existing channels?
  4315. @cindex channel introduction
  4316. Channel introductions answer these questions by describing the first
  4317. commit of a channel that should be authenticated. The first time a
  4318. channel is fetched with @command{guix pull} or @command{guix
  4319. time-machine}, the command looks up the introductory commit and verifies
  4320. that it is signed by the specified OpenPGP key. From then on, it
  4321. authenticates commits according to the rule above.
  4322. Additionally, your channel must provide all the OpenPGP keys that were
  4323. ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
  4324. files, which can be either binary or ``ASCII-armored''. By default,
  4325. those @file{.key} files are searched for in the branch named
  4326. @code{keyring} but you can specify a different branch name in
  4327. @code{.guix-channel} like so:
  4328. @lisp
  4329. (channel
  4330. (version 0)
  4331. (keyring-reference "my-keyring-branch"))
  4332. @end lisp
  4333. To summarize, as the author of a channel, there are three things you have
  4334. to do to allow users to authenticate your code:
  4335. @enumerate
  4336. @item
  4337. Export the OpenPGP keys of past and present committers with @command{gpg
  4338. --export} and store them in @file{.key} files, by default in a branch
  4339. named @code{keyring} (we recommend making it an @dfn{orphan branch}).
  4340. @item
  4341. Introduce an initial @file{.guix-authorizations} in the channel's
  4342. repository. Do that in a signed commit (@pxref{Commit Access}, for
  4343. information on how to sign Git commits.)
  4344. @item
  4345. Advertise the channel introduction, for instance on your channel's web
  4346. page. The channel introduction, as we saw above, is the commit/key
  4347. pair---i.e., the commit that introduced @file{.guix-authorizations}, and
  4348. the fingerprint of the OpenPGP used to sign it.
  4349. @end enumerate
  4350. Before pushing to your public Git repository, you can run @command{guix
  4351. git-authenticate} to verify that you did sign all the commits you are
  4352. about to push with an authorized key:
  4353. @example
  4354. guix git authenticate @var{commit} @var{signer}
  4355. @end example
  4356. @noindent
  4357. where @var{commit} and @var{signer} are your channel introduction.
  4358. @xref{Invoking guix git authenticate}, for details.
  4359. Publishing a signed channel requires discipline: any mistake, such as an
  4360. unsigned commit or a commit signed by an unauthorized key, will prevent
  4361. users from pulling from your channel---well, that's the whole point of
  4362. authentication! Pay attention to merges in particular: merge commits
  4363. are considered authentic if and only if they are signed by a key present
  4364. in the @file{.guix-authorizations} file of @emph{both} branches.
  4365. @node Primary URL
  4366. @section Primary URL
  4367. @cindex primary URL, channels
  4368. Channel authors can indicate the primary URL of their channel's Git
  4369. repository in the @file{.guix-channel} file, like so:
  4370. @lisp
  4371. (channel
  4372. (version 0)
  4373. (url "https://example.org/guix.git"))
  4374. @end lisp
  4375. This allows @command{guix pull} to determine whether it is pulling code
  4376. from a mirror of the channel; when that is the case, it warns the user
  4377. that the mirror might be stale and displays the primary URL@. That way,
  4378. users cannot be tricked into fetching code from a stale mirror that does
  4379. not receive security updates.
  4380. This feature only makes sense for authenticated repositories, such as
  4381. the official @code{guix} channel, for which @command{guix pull} ensures
  4382. the code it fetches is authentic.
  4383. @node Writing Channel News
  4384. @section Writing Channel News
  4385. @cindex news, for channels
  4386. Channel authors may occasionally want to communicate to their users
  4387. information about important changes in the channel. You'd send them all
  4388. an email, but that's not convenient.
  4389. Instead, channels can provide a @dfn{news file}; when the channel users
  4390. run @command{guix pull}, that news file is automatically read and
  4391. @command{guix pull --news} can display the announcements that correspond
  4392. to the new commits that have been pulled, if any.
  4393. To do that, channel authors must first declare the name of the news file
  4394. in their @file{.guix-channel} file:
  4395. @lisp
  4396. (channel
  4397. (version 0)
  4398. (news-file "etc/news.txt"))
  4399. @end lisp
  4400. The news file itself, @file{etc/news.txt} in this example, must look
  4401. something like this:
  4402. @lisp
  4403. (channel-news
  4404. (version 0)
  4405. (entry (tag "the-bug-fix")
  4406. (title (en "Fixed terrible bug")
  4407. (fr "Oh la la"))
  4408. (body (en "@@emph@{Good news@}! It's fixed!")
  4409. (eo "Certe ĝi pli bone funkcias nun!")))
  4410. (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
  4411. (title (en "Added a great package")
  4412. (ca "Què vol dir guix?"))
  4413. (body (en "Don't miss the @@code@{hello@} package!"))))
  4414. @end lisp
  4415. While the news file is using the Scheme syntax, avoid naming it with a
  4416. @file{.scm} extension or else it will get picked up when building the
  4417. channel and yield an error since it is not a valid module.
  4418. Alternatively, you can move the channel module to a subdirectory and
  4419. store the news file in another directory.
  4420. The file consists of a list of @dfn{news entries}. Each entry is
  4421. associated with a commit or tag: it describes changes made in this
  4422. commit, possibly in preceding commits as well. Users see entries only
  4423. the first time they obtain the commit the entry refers to.
  4424. The @code{title} field should be a one-line summary while @code{body}
  4425. can be arbitrarily long, and both can contain Texinfo markup
  4426. (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
  4427. a list of language tag/message tuples, which allows @command{guix pull}
  4428. to display news in the language that corresponds to the user's locale.
  4429. If you want to translate news using a gettext-based workflow, you can
  4430. extract translatable strings with @command{xgettext} (@pxref{xgettext
  4431. Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
  4432. you write news entries in English first, the command below creates a PO
  4433. file containing the strings to translate:
  4434. @example
  4435. xgettext -o news.po -l scheme -ken etc/news.txt
  4436. @end example
  4437. To sum up, yes, you could use your channel as a blog. But beware, this
  4438. is @emph{not quite} what your users might expect.
  4439. @node Channels with Substitutes
  4440. @section Channels with Substitutes
  4441. When running @command{guix pull}, Guix will first compile the
  4442. definitions of every available package. This is an expensive operation
  4443. for which substitutes (@pxref{Substitutes}) may be available. The
  4444. following snippet in @file{channels.scm} will ensure that @command{guix
  4445. pull} uses the latest commit with available substitutes for the package
  4446. definitions: this is done by querying the continuous integration
  4447. server at @url{https://ci.guix.gnu.org}.
  4448. @lisp
  4449. (use-modules (guix ci))
  4450. (list (channel-with-substitutes-available
  4451. %default-guix-channel
  4452. "https://ci.guix.gnu.org"))
  4453. @end lisp
  4454. Note that this does not mean that all the packages that you will
  4455. install after running @command{guix pull} will have available
  4456. substitutes. It only ensures that @command{guix pull} will not try to
  4457. compile package definitions. This is particularly useful when using
  4458. machines with limited resources.
  4459. @c *********************************************************************
  4460. @node Development
  4461. @chapter Development
  4462. @cindex software development
  4463. If you are a software developer, Guix provides tools that you should find
  4464. helpful---independently of the language you're developing in. This is what
  4465. this chapter is about.
  4466. The @command{guix environment} command provides a convenient way to set up
  4467. @dfn{development environments} containing all the dependencies and tools
  4468. necessary to work on the software package of your choice. The @command{guix
  4469. pack} command allows you to create @dfn{application bundles} that can be
  4470. easily distributed to users who do not run Guix.
  4471. @menu
  4472. * Invoking guix environment:: Setting up development environments.
  4473. * Invoking guix pack:: Creating software bundles.
  4474. * The GCC toolchain:: Working with languages supported by GCC.
  4475. * Invoking guix git authenticate:: Authenticating Git repositories.
  4476. @end menu
  4477. @node Invoking guix environment
  4478. @section Invoking @command{guix environment}
  4479. @cindex reproducible build environments
  4480. @cindex development environments
  4481. @cindex @command{guix environment}
  4482. @cindex environment, package build environment
  4483. The purpose of @command{guix environment} is to assist hackers in
  4484. creating reproducible development environments without polluting their
  4485. package profile. The @command{guix environment} tool takes one or more
  4486. packages, builds all of their inputs, and creates a shell
  4487. environment to use them.
  4488. The general syntax is:
  4489. @example
  4490. guix environment @var{options} @var{package}@dots{}
  4491. @end example
  4492. The following example spawns a new shell set up for the development of
  4493. GNU@tie{}Guile:
  4494. @example
  4495. guix environment guile
  4496. @end example
  4497. If the needed dependencies are not built yet, @command{guix environment}
  4498. automatically builds them. The environment of the new shell is an
  4499. augmented version of the environment that @command{guix environment} was
  4500. run in. It contains the necessary search paths for building the given
  4501. package added to the existing environment variables. To create
  4502. a ``pure'' environment, in which the original environment variables have
  4503. been unset, use the @option{--pure} option@footnote{Users sometimes
  4504. wrongfully augment environment variables such as @env{PATH} in their
  4505. @file{~/.bashrc} file. As a consequence, when @command{guix
  4506. environment} launches it, Bash may read @file{~/.bashrc}, thereby
  4507. introducing ``impurities'' in these environment variables. It is an
  4508. error to define such environment variables in @file{.bashrc}; instead,
  4509. they should be defined in @file{.bash_profile}, which is sourced only by
  4510. log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
  4511. Manual}, for details on Bash start-up files.}.
  4512. Exiting from a Guix environment is the same as exiting from the shell,
  4513. and will place the user back in the old environment before @command{guix
  4514. environment} was invoked. The next garbage collection (@pxref{Invoking
  4515. guix gc}) will clean up packages that were installed from within the
  4516. environment and are no longer used outside of it.
  4517. @vindex GUIX_ENVIRONMENT
  4518. @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
  4519. variable in the shell it spawns; its value is the file name of the
  4520. profile of this environment. This allows users to, say, define a
  4521. specific prompt for development environments in their @file{.bashrc}
  4522. (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
  4523. @example
  4524. if [ -n "$GUIX_ENVIRONMENT" ]
  4525. then
  4526. export PS1="\u@@\h \w [dev]\$ "
  4527. fi
  4528. @end example
  4529. @noindent
  4530. ...@: or to browse the profile:
  4531. @example
  4532. $ ls "$GUIX_ENVIRONMENT/bin"
  4533. @end example
  4534. Additionally, more than one package may be specified, in which case the
  4535. union of the inputs for the given packages are used. For example, the
  4536. command below spawns a shell where all of the dependencies of both Guile
  4537. and Emacs are available:
  4538. @example
  4539. guix environment guile emacs
  4540. @end example
  4541. Sometimes an interactive shell session is not desired. An arbitrary
  4542. command may be invoked by placing the @code{--} token to separate the
  4543. command from the rest of the arguments:
  4544. @example
  4545. guix environment guile -- make -j4
  4546. @end example
  4547. In other situations, it is more convenient to specify the list of
  4548. packages needed in the environment. For example, the following command
  4549. runs @command{python} from an environment containing Python@tie{}2.7 and
  4550. NumPy:
  4551. @example
  4552. guix environment --ad-hoc python2-numpy python-2.7 -- python
  4553. @end example
  4554. Furthermore, one might want the dependencies of a package and also some
  4555. additional packages that are not build-time or runtime dependencies, but
  4556. are useful when developing nonetheless. Because of this, the
  4557. @option{--ad-hoc} flag is positional. Packages appearing before
  4558. @option{--ad-hoc} are interpreted as packages whose dependencies will be
  4559. added to the environment. Packages appearing after are interpreted as
  4560. packages that will be added to the environment directly. For example,
  4561. the following command creates a Guix development environment that
  4562. additionally includes Git and strace:
  4563. @example
  4564. guix environment --pure guix --ad-hoc git strace
  4565. @end example
  4566. @cindex container
  4567. Sometimes it is desirable to isolate the environment as much as
  4568. possible, for maximal purity and reproducibility. In particular, when
  4569. using Guix on a host distro that is not Guix System, it is desirable to
  4570. prevent access to @file{/usr/bin} and other system-wide resources from
  4571. the development environment. For example, the following command spawns
  4572. a Guile REPL in a ``container'' where only the store and the current
  4573. working directory are mounted:
  4574. @example
  4575. guix environment --ad-hoc --container guile -- guile
  4576. @end example
  4577. @quotation Note
  4578. The @option{--container} option requires Linux-libre 3.19 or newer.
  4579. @end quotation
  4580. @cindex certificates
  4581. Another typical use case for containers is to run security-sensitive
  4582. applications such as a web browser. To run Eolie, we must expose and
  4583. share some files and directories; we include @code{nss-certs} and expose
  4584. @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
  4585. @env{DISPLAY} environment variable since containerized graphical
  4586. applications won't display without it.
  4587. @example
  4588. guix environment --preserve='^DISPLAY$' --container --network \
  4589. --expose=/etc/machine-id \
  4590. --expose=/etc/ssl/certs/ \
  4591. --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
  4592. --ad-hoc eolie nss-certs dbus -- eolie
  4593. @end example
  4594. The available options are summarized below.
  4595. @table @code
  4596. @item --root=@var{file}
  4597. @itemx -r @var{file}
  4598. @cindex persistent environment
  4599. @cindex garbage collector root, for environments
  4600. Make @var{file} a symlink to the profile for this environment, and
  4601. register it as a garbage collector root.
  4602. This is useful if you want to protect your environment from garbage
  4603. collection, to make it ``persistent''.
  4604. When this option is omitted, the environment is protected from garbage
  4605. collection only for the duration of the @command{guix environment}
  4606. session. This means that next time you recreate the same environment,
  4607. you could have to rebuild or re-download packages. @xref{Invoking guix
  4608. gc}, for more on GC roots.
  4609. @item --expression=@var{expr}
  4610. @itemx -e @var{expr}
  4611. Create an environment for the package or list of packages that
  4612. @var{expr} evaluates to.
  4613. For example, running:
  4614. @example
  4615. guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
  4616. @end example
  4617. starts a shell with the environment for this specific variant of the
  4618. PETSc package.
  4619. Running:
  4620. @example
  4621. guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
  4622. @end example
  4623. starts a shell with all the base system packages available.
  4624. The above commands only use the default output of the given packages.
  4625. To select other outputs, two element tuples can be specified:
  4626. @example
  4627. guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
  4628. @end example
  4629. @item --load=@var{file}
  4630. @itemx -l @var{file}
  4631. Create an environment for the package or list of packages that the code
  4632. within @var{file} evaluates to.
  4633. As an example, @var{file} might contain a definition like this
  4634. (@pxref{Defining Packages}):
  4635. @lisp
  4636. @verbatiminclude environment-gdb.scm
  4637. @end lisp
  4638. @item --manifest=@var{file}
  4639. @itemx -m @var{file}
  4640. Create an environment for the packages contained in the manifest object
  4641. returned by the Scheme code in @var{file}. This option can be repeated
  4642. several times, in which case the manifests are concatenated.
  4643. This is similar to the same-named option in @command{guix package}
  4644. (@pxref{profile-manifest, @option{--manifest}}) and uses the same
  4645. manifest files.
  4646. @item --ad-hoc
  4647. Include all specified packages in the resulting environment, as if an
  4648. @i{ad hoc} package were defined with them as inputs. This option is
  4649. useful for quickly creating an environment without having to write a
  4650. package expression to contain the desired inputs.
  4651. For instance, the command:
  4652. @example
  4653. guix environment --ad-hoc guile guile-sdl -- guile
  4654. @end example
  4655. runs @command{guile} in an environment where Guile and Guile-SDL are
  4656. available.
  4657. Note that this example implicitly asks for the default output of
  4658. @code{guile} and @code{guile-sdl}, but it is possible to ask for a
  4659. specific output---e.g., @code{glib:bin} asks for the @code{bin} output
  4660. of @code{glib} (@pxref{Packages with Multiple Outputs}).
  4661. This option may be composed with the default behavior of @command{guix
  4662. environment}. Packages appearing before @option{--ad-hoc} are
  4663. interpreted as packages whose dependencies will be added to the
  4664. environment, the default behavior. Packages appearing after are
  4665. interpreted as packages that will be added to the environment directly.
  4666. @item --pure
  4667. Unset existing environment variables when building the new environment, except
  4668. those specified with @option{--preserve} (see below). This has the effect of
  4669. creating an environment in which search paths only contain package inputs.
  4670. @item --preserve=@var{regexp}
  4671. @itemx -E @var{regexp}
  4672. When used alongside @option{--pure}, preserve the environment variables
  4673. matching @var{regexp}---in other words, put them on a ``white list'' of
  4674. environment variables that must be preserved. This option can be repeated
  4675. several times.
  4676. @example
  4677. guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
  4678. -- mpirun @dots{}
  4679. @end example
  4680. This example runs @command{mpirun} in a context where the only environment
  4681. variables defined are @env{PATH}, environment variables whose name starts
  4682. with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
  4683. @env{USER}, etc.).
  4684. @item --search-paths
  4685. Display the environment variable definitions that make up the
  4686. environment.
  4687. @item --system=@var{system}
  4688. @itemx -s @var{system}
  4689. Attempt to build for @var{system}---e.g., @code{i686-linux}.
  4690. @item --container
  4691. @itemx -C
  4692. @cindex container
  4693. Run @var{command} within an isolated container. The current working
  4694. directory outside the container is mapped inside the container.
  4695. Additionally, unless overridden with @option{--user}, a dummy home
  4696. directory is created that matches the current user's home directory, and
  4697. @file{/etc/passwd} is configured accordingly.
  4698. The spawned process runs as the current user outside the container. Inside
  4699. the container, it has the same UID and GID as the current user, unless
  4700. @option{--user} is passed (see below).
  4701. @item --network
  4702. @itemx -N
  4703. For containers, share the network namespace with the host system.
  4704. Containers created without this flag only have access to the loopback
  4705. device.
  4706. @item --link-profile
  4707. @itemx -P
  4708. For containers, link the environment profile to @file{~/.guix-profile}
  4709. within the container and set @code{GUIX_ENVIRONMENT} to that.
  4710. This is equivalent to making @file{~/.guix-profile} a symlink to the
  4711. actual profile within the container.
  4712. Linking will fail and abort the environment if the directory already
  4713. exists, which will certainly be the case if @command{guix environment}
  4714. was invoked in the user's home directory.
  4715. Certain packages are configured to look in @file{~/.guix-profile} for
  4716. configuration files and data;@footnote{For example, the
  4717. @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
  4718. for additional fonts.} @option{--link-profile} allows these programs to
  4719. behave as expected within the environment.
  4720. @item --user=@var{user}
  4721. @itemx -u @var{user}
  4722. For containers, use the username @var{user} in place of the current
  4723. user. The generated @file{/etc/passwd} entry within the container will
  4724. contain the name @var{user}, the home directory will be
  4725. @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
  4726. the UID and GID inside the container are 1000. @var{user}
  4727. need not exist on the system.
  4728. Additionally, any shared or exposed path (see @option{--share} and
  4729. @option{--expose} respectively) whose target is within the current user's
  4730. home directory will be remapped relative to @file{/home/USER}; this
  4731. includes the automatic mapping of the current working directory.
  4732. @example
  4733. # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
  4734. cd $HOME/wd
  4735. guix environment --container --user=foo \
  4736. --expose=$HOME/test \
  4737. --expose=/tmp/target=$HOME/target
  4738. @end example
  4739. While this will limit the leaking of user identity through home paths
  4740. and each of the user fields, this is only one useful component of a
  4741. broader privacy/anonymity solution---not one in and of itself.
  4742. @item --no-cwd
  4743. For containers, the default behavior is to share the current working
  4744. directory with the isolated container and immediately change to that
  4745. directory within the container. If this is undesirable,
  4746. @option{--no-cwd} will cause the current working directory to @emph{not}
  4747. be automatically shared and will change to the user's home directory
  4748. within the container instead. See also @option{--user}.
  4749. @item --expose=@var{source}[=@var{target}]
  4750. @itemx --share=@var{source}[=@var{target}]
  4751. For containers, @option{--expose} (resp. @option{--share}) exposes the
  4752. file system @var{source} from the host system as the read-only
  4753. (resp. writable) file system @var{target} within the container. If
  4754. @var{target} is not specified, @var{source} is used as the target mount
  4755. point in the container.
  4756. The example below spawns a Guile REPL in a container in which the user's
  4757. home directory is accessible read-only via the @file{/exchange}
  4758. directory:
  4759. @example
  4760. guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
  4761. @end example
  4762. @end table
  4763. @command{guix environment}
  4764. also supports all of the common build options that @command{guix
  4765. build} supports (@pxref{Common Build Options}) as well as package
  4766. transformation options (@pxref{Package Transformation Options}).
  4767. @node Invoking guix pack
  4768. @section Invoking @command{guix pack}
  4769. Occasionally you want to pass software to people who are not (yet!)
  4770. lucky enough to be using Guix. You'd tell them to run @command{guix
  4771. package -i @var{something}}, but that's not possible in this case. This
  4772. is where @command{guix pack} comes in.
  4773. @quotation Note
  4774. If you are looking for ways to exchange binaries among machines that
  4775. already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
  4776. publish}, and @ref{Invoking guix archive}.
  4777. @end quotation
  4778. @cindex pack
  4779. @cindex bundle
  4780. @cindex application bundle
  4781. @cindex software bundle
  4782. The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
  4783. @dfn{software bundle}: it creates a tarball or some other archive
  4784. containing the binaries of the software you're interested in, and all
  4785. its dependencies. The resulting archive can be used on any machine that
  4786. does not have Guix, and people can run the exact same binaries as those
  4787. you have with Guix. The pack itself is created in a bit-reproducible
  4788. fashion, so anyone can verify that it really contains the build results
  4789. that you pretend to be shipping.
  4790. For example, to create a bundle containing Guile, Emacs, Geiser, and all
  4791. their dependencies, you can run:
  4792. @example
  4793. $ guix pack guile emacs geiser
  4794. @dots{}
  4795. /gnu/store/@dots{}-pack.tar.gz
  4796. @end example
  4797. The result here is a tarball containing a @file{/gnu/store} directory
  4798. with all the relevant packages. The resulting tarball contains a
  4799. @dfn{profile} with the three packages of interest; the profile is the
  4800. same as would be created by @command{guix package -i}. It is this
  4801. mechanism that is used to create Guix's own standalone binary tarball
  4802. (@pxref{Binary Installation}).
  4803. Users of this pack would have to run
  4804. @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
  4805. find inconvenient. To work around it, you can create, say, a
  4806. @file{/opt/gnu/bin} symlink to the profile:
  4807. @example
  4808. guix pack -S /opt/gnu/bin=bin guile emacs geiser
  4809. @end example
  4810. @noindent
  4811. That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
  4812. @cindex relocatable binaries, with @command{guix pack}
  4813. What if the recipient of your pack does not have root privileges on
  4814. their machine, and thus cannot unpack it in the root file system? In
  4815. that case, you will want to use the @option{--relocatable} option (see
  4816. below). This option produces @dfn{relocatable binaries}, meaning they
  4817. they can be placed anywhere in the file system hierarchy: in the example
  4818. above, users can unpack your tarball in their home directory and
  4819. directly run @file{./opt/gnu/bin/guile}.
  4820. @cindex Docker, build an image with guix pack
  4821. Alternatively, you can produce a pack in the Docker image format using
  4822. the following command:
  4823. @example
  4824. guix pack -f docker -S /bin=bin guile guile-readline
  4825. @end example
  4826. @noindent
  4827. The result is a tarball that can be passed to the @command{docker load}
  4828. command, followed by @code{docker run}:
  4829. @example
  4830. docker load < @var{file}
  4831. docker run -ti guile-guile-readline /bin/guile
  4832. @end example
  4833. @noindent
  4834. where @var{file} is the image returned by @var{guix pack}, and
  4835. @code{guile-guile-readline} is its ``image tag''. See the
  4836. @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
  4837. documentation} for more information.
  4838. @cindex Singularity, build an image with guix pack
  4839. @cindex SquashFS, build an image with guix pack
  4840. Yet another option is to produce a SquashFS image with the following
  4841. command:
  4842. @example
  4843. guix pack -f squashfs bash guile emacs geiser
  4844. @end example
  4845. @noindent
  4846. The result is a SquashFS file system image that can either be mounted or
  4847. directly be used as a file system container image with the
  4848. @uref{https://www.sylabs.io/docs/, Singularity container execution
  4849. environment}, using commands like @command{singularity shell} or
  4850. @command{singularity exec}.
  4851. Several command-line options allow you to customize your pack:
  4852. @table @code
  4853. @item --format=@var{format}
  4854. @itemx -f @var{format}
  4855. Produce a pack in the given @var{format}.
  4856. The available formats are:
  4857. @table @code
  4858. @item tarball
  4859. This is the default format. It produces a tarball containing all the
  4860. specified binaries and symlinks.
  4861. @item docker
  4862. This produces a tarball that follows the
  4863. @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
  4864. Docker Image Specification}. The ``repository name'' as it appears in
  4865. the output of the @command{docker images} command is computed from
  4866. package names passed on the command line or in the manifest file.
  4867. @item squashfs
  4868. This produces a SquashFS image containing all the specified binaries and
  4869. symlinks, as well as empty mount points for virtual file systems like
  4870. procfs.
  4871. @quotation Note
  4872. Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
  4873. For that reason, @command{guix pack -f squashfs} always implies @code{-S
  4874. /bin=bin}. Thus, your @command{guix pack} invocation must always start
  4875. with something like:
  4876. @example
  4877. guix pack -f squashfs bash @dots{}
  4878. @end example
  4879. If you forget the @code{bash} (or similar) package, @command{singularity
  4880. run} and @command{singularity exec} will fail with an unhelpful ``no
  4881. such file or directory'' message.
  4882. @end quotation
  4883. @end table
  4884. @cindex relocatable binaries
  4885. @item --relocatable
  4886. @itemx -R
  4887. Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
  4888. anywhere in the file system hierarchy and run from there.
  4889. When this option is passed once, the resulting binaries require support for
  4890. @dfn{user namespaces} in the kernel Linux; when passed
  4891. @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
  4892. PRoot support, can be thought of as the abbreviation of ``Really
  4893. Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
  4894. other techniques if user namespaces are unavailable, and essentially
  4895. work anywhere---see below for the implications.
  4896. For example, if you create a pack containing Bash with:
  4897. @example
  4898. guix pack -RR -S /mybin=bin bash
  4899. @end example
  4900. @noindent
  4901. ...@: you can copy that pack to a machine that lacks Guix, and from your
  4902. home directory as a normal user, run:
  4903. @example
  4904. tar xf pack.tar.gz
  4905. ./mybin/sh
  4906. @end example
  4907. @noindent
  4908. In that shell, if you type @code{ls /gnu/store}, you'll notice that
  4909. @file{/gnu/store} shows up and contains all the dependencies of
  4910. @code{bash}, even though the machine actually lacks @file{/gnu/store}
  4911. altogether! That is probably the simplest way to deploy Guix-built
  4912. software on a non-Guix machine.
  4913. @quotation Note
  4914. By default, relocatable binaries rely on the @dfn{user namespace} feature of
  4915. the kernel Linux, which allows unprivileged users to mount or change root.
  4916. Old versions of Linux did not support it, and some GNU/Linux distributions
  4917. turn it off.
  4918. To produce relocatable binaries that work even in the absence of user
  4919. namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
  4920. case, binaries will try user namespace support and fall back to another
  4921. @dfn{execution engine} if user namespaces are not supported. The
  4922. following execution engines are supported:
  4923. @table @code
  4924. @item default
  4925. Try user namespaces and fall back to PRoot if user namespaces are not
  4926. supported (see below).
  4927. @item performance
  4928. Try user namespaces and fall back to Fakechroot if user namespaces are
  4929. not supported (see below).
  4930. @item userns
  4931. Run the program through user namespaces and abort if they are not
  4932. supported.
  4933. @item proot
  4934. Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
  4935. provides the necessary
  4936. support for file system virtualization. It achieves that by using the
  4937. @code{ptrace} system call on the running program. This approach has the
  4938. advantage to work without requiring special kernel support, but it incurs
  4939. run-time overhead every time a system call is made.
  4940. @item fakechroot
  4941. Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
  4942. Fakechroot} virtualizes file system accesses by intercepting calls to C
  4943. library functions such as @code{open}, @code{stat}, @code{exec}, and so
  4944. on. Unlike PRoot, it incurs very little overhead. However, it does not
  4945. always work: for example, some file system accesses made from within the
  4946. C library are not intercepted, and file system accesses made @i{via}
  4947. direct syscalls are not intercepted either, leading to erratic behavior.
  4948. @end table
  4949. @vindex GUIX_EXECUTION_ENGINE
  4950. When running a wrapped program, you can explicitly request one of the
  4951. execution engines listed above by setting the
  4952. @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
  4953. @end quotation
  4954. @cindex entry point, for Docker images
  4955. @item --entry-point=@var{command}
  4956. Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
  4957. format supports it---currently @code{docker} and @code{squashfs} (Singularity)
  4958. support it. @var{command} must be relative to the profile contained in the
  4959. pack.
  4960. The entry point specifies the command that tools like @code{docker run} or
  4961. @code{singularity run} automatically start by default. For example, you can
  4962. do:
  4963. @example
  4964. guix pack -f docker --entry-point=bin/guile guile
  4965. @end example
  4966. The resulting pack can easily be loaded and @code{docker run} with no extra
  4967. arguments will spawn @code{bin/guile}:
  4968. @example
  4969. docker load -i pack.tar.gz
  4970. docker run @var{image-id}
  4971. @end example
  4972. @item --expression=@var{expr}
  4973. @itemx -e @var{expr}
  4974. Consider the package @var{expr} evaluates to.
  4975. This has the same purpose as the same-named option in @command{guix
  4976. build} (@pxref{Additional Build Options, @option{--expression} in
  4977. @command{guix build}}).
  4978. @item --manifest=@var{file}
  4979. @itemx -m @var{file}
  4980. Use the packages contained in the manifest object returned by the Scheme
  4981. code in @var{file}. This option can be repeated several times, in which
  4982. case the manifests are concatenated.
  4983. This has a similar purpose as the same-named option in @command{guix
  4984. package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
  4985. same manifest files. It allows you to define a collection of packages
  4986. once and use it both for creating profiles and for creating archives
  4987. for use on machines that do not have Guix installed. Note that you can
  4988. specify @emph{either} a manifest file @emph{or} a list of packages,
  4989. but not both.
  4990. @item --system=@var{system}
  4991. @itemx -s @var{system}
  4992. Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
  4993. the system type of the build host.
  4994. @item --target=@var{triplet}
  4995. @cindex cross-compilation
  4996. Cross-build for @var{triplet}, which must be a valid GNU triplet, such
  4997. as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
  4998. configuration triplets,, autoconf, Autoconf}).
  4999. @item --compression=@var{tool}
  5000. @itemx -C @var{tool}
  5001. Compress the resulting tarball using @var{tool}---one of @code{gzip},
  5002. @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
  5003. compression.
  5004. @item --symlink=@var{spec}
  5005. @itemx -S @var{spec}
  5006. Add the symlinks specified by @var{spec} to the pack. This option can
  5007. appear several times.
  5008. @var{spec} has the form @code{@var{source}=@var{target}}, where
  5009. @var{source} is the symlink that will be created and @var{target} is the
  5010. symlink target.
  5011. For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
  5012. symlink pointing to the @file{bin} sub-directory of the profile.
  5013. @item --save-provenance
  5014. Save provenance information for the packages passed on the command line.
  5015. Provenance information includes the URL and commit of the channels in use
  5016. (@pxref{Channels}).
  5017. Provenance information is saved in the
  5018. @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
  5019. usual package metadata---the name and version of each package, their
  5020. propagated inputs, and so on. It is useful information to the recipient of
  5021. the pack, who then knows how the pack was (supposedly) obtained.
  5022. This option is not enabled by default because, like timestamps, provenance
  5023. information contributes nothing to the build process. In other words, there
  5024. is an infinity of channel URLs and commit IDs that can lead to the same pack.
  5025. Recording such ``silent'' metadata in the output thus potentially breaks the
  5026. source-to-binary bitwise reproducibility property.
  5027. @item --root=@var{file}
  5028. @itemx -r @var{file}
  5029. @cindex garbage collector root, for packs
  5030. Make @var{file} a symlink to the resulting pack, and register it as a garbage
  5031. collector root.
  5032. @item --localstatedir
  5033. @itemx --profile-name=@var{name}
  5034. Include the ``local state directory'', @file{/var/guix}, in the resulting
  5035. pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
  5036. profile---by default @var{name} is @code{guix-profile}, which corresponds to
  5037. @file{~root/.guix-profile}.
  5038. @file{/var/guix} contains the store database (@pxref{The Store}) as well
  5039. as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
  5040. the pack means that the store is ``complete'' and manageable by Guix;
  5041. not providing it pack means that the store is ``dead'': items cannot be
  5042. added to it or removed from it after extraction of the pack.
  5043. One use case for this is the Guix self-contained binary tarball
  5044. (@pxref{Binary Installation}).
  5045. @item --derivation
  5046. @itemx -d
  5047. Print the name of the derivation that builds the pack.
  5048. @item --bootstrap
  5049. Use the bootstrap binaries to build the pack. This option is only
  5050. useful to Guix developers.
  5051. @end table
  5052. In addition, @command{guix pack} supports all the common build options
  5053. (@pxref{Common Build Options}) and all the package transformation
  5054. options (@pxref{Package Transformation Options}).
  5055. @node The GCC toolchain
  5056. @section The GCC toolchain
  5057. @cindex GCC
  5058. @cindex ld-wrapper
  5059. @cindex linker wrapper
  5060. @cindex toolchain, for C development
  5061. @cindex toolchain, for Fortran development
  5062. If you need a complete toolchain for compiling and linking C or C++
  5063. source code, use the @code{gcc-toolchain} package. This package
  5064. provides a complete GCC toolchain for C/C++ development, including GCC
  5065. itself, the GNU C Library (headers and binaries, plus debugging symbols
  5066. in the @code{debug} output), Binutils, and a linker wrapper.
  5067. The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
  5068. passed to the linker, add corresponding @code{-rpath} arguments, and
  5069. invoke the actual linker with this new set of arguments. You can instruct the
  5070. wrapper to refuse to link against libraries not in the store by setting the
  5071. @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
  5072. The package @code{gfortran-toolchain} provides a complete GCC toolchain
  5073. for Fortran development. For other languages, please use
  5074. @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
  5075. @node Invoking guix git authenticate
  5076. @section Invoking @command{guix git authenticate}
  5077. The @command{guix git authenticate} command authenticates a Git checkout
  5078. following the same rule as for channels (@pxref{channel-authentication,
  5079. channel authentication}). That is, starting from a given commit, it
  5080. ensures that all subsequent commits are signed by an OpenPGP key whose
  5081. fingerprint appears in the @file{.guix-authorizations} file of its
  5082. parent commit(s).
  5083. You will find this command useful if you maintain a channel. But in
  5084. fact, this authentication mechanism is useful in a broader context, so
  5085. you might want to use it for Git repositories that have nothing to do
  5086. with Guix.
  5087. The general syntax is:
  5088. @example
  5089. guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
  5090. @end example
  5091. By default, this command authenticates the Git checkout in the current
  5092. directory; it outputs nothing and exits with exit code zero on success
  5093. and non-zero on failure. @var{commit} above denotes the first commit
  5094. where authentication takes place, and @var{signer} is the OpenPGP
  5095. fingerprint of public key used to sign @var{commit}. Together, they
  5096. form a ``channel introduction'' (@pxref{channel-authentication, channel
  5097. introduction}). The options below allow you to fine-tune the process.
  5098. @table @code
  5099. @item --repository=@var{directory}
  5100. @itemx -r @var{directory}
  5101. Open the Git repository in @var{directory} instead of the current
  5102. directory.
  5103. @item --keyring=@var{reference}
  5104. @itemx -k @var{reference}
  5105. Load OpenPGP keyring from @var{reference}, the reference of a branch
  5106. such as @code{origin/keyring} or @code{my-keyring}. The branch must
  5107. contain OpenPGP public keys in @file{.key} files, either in binary form
  5108. or ``ASCII-armored''. By default the keyring is loaded from the branch
  5109. named @code{keyring}.
  5110. @item --stats
  5111. Display commit signing statistics upon completion.
  5112. @item --cache-key=@var{key}
  5113. Previously-authenticated commits are cached in a file under
  5114. @file{~/.cache/guix/authentication}. This option forces the cache to be
  5115. stored in file @var{key} in that directory.
  5116. @item --historical-authorizations=@var{file}
  5117. By default, any commit whose parent commit(s) lack the
  5118. @file{.guix-authorizations} file is considered inauthentic. In
  5119. contrast, this option considers the authorizations in @var{file} for any
  5120. commit that lacks @file{.guix-authorizations}. The format of @var{file}
  5121. is the same as that of @file{.guix-authorizations}
  5122. (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
  5123. @end table
  5124. @c *********************************************************************
  5125. @node Programming Interface
  5126. @chapter Programming Interface
  5127. GNU Guix provides several Scheme programming interfaces (APIs) to
  5128. define, build, and query packages. The first interface allows users to
  5129. write high-level package definitions. These definitions refer to
  5130. familiar packaging concepts, such as the name and version of a package,
  5131. its build system, and its dependencies. These definitions can then be
  5132. turned into concrete build actions.
  5133. Build actions are performed by the Guix daemon, on behalf of users. In a
  5134. standard setup, the daemon has write access to the store---the
  5135. @file{/gnu/store} directory---whereas users do not. The recommended
  5136. setup also has the daemon perform builds in chroots, under specific
  5137. build users, to minimize interference with the rest of the system.
  5138. @cindex derivation
  5139. Lower-level APIs are available to interact with the daemon and the
  5140. store. To instruct the daemon to perform a build action, users actually
  5141. provide it with a @dfn{derivation}. A derivation is a low-level
  5142. representation of the build actions to be taken, and the environment in
  5143. which they should occur---derivations are to package definitions what
  5144. assembly is to C programs. The term ``derivation'' comes from the fact
  5145. that build results @emph{derive} from them.
  5146. This chapter describes all these APIs in turn, starting from high-level
  5147. package definitions.
  5148. @menu
  5149. * Package Modules:: Packages from the programmer's viewpoint.
  5150. * Defining Packages:: Defining new packages.
  5151. * Defining Package Variants:: Customizing packages.
  5152. * Build Systems:: Specifying how packages are built.
  5153. * Build Phases:: Phases of the build process of a package.
  5154. * Build Utilities:: Helpers for your package definitions and more.
  5155. * The Store:: Manipulating the package store.
  5156. * Derivations:: Low-level interface to package derivations.
  5157. * The Store Monad:: Purely functional interface to the store.
  5158. * G-Expressions:: Manipulating build expressions.
  5159. * Invoking guix repl:: Programming Guix in Guile
  5160. @end menu
  5161. @node Package Modules
  5162. @section Package Modules
  5163. From a programming viewpoint, the package definitions of the
  5164. GNU distribution are provided by Guile modules in the @code{(gnu packages
  5165. @dots{})} name space@footnote{Note that packages under the @code{(gnu
  5166. packages @dots{})} module name space are not necessarily ``GNU
  5167. packages''. This module naming scheme follows the usual Guile module
  5168. naming convention: @code{gnu} means that these modules are distributed
  5169. as part of the GNU system, and @code{packages} identifies modules that
  5170. define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
  5171. Reference Manual}). For instance, the @code{(gnu packages emacs)}
  5172. module exports a variable named @code{emacs}, which is bound to a
  5173. @code{<package>} object (@pxref{Defining Packages}).
  5174. The @code{(gnu packages @dots{})} module name space is
  5175. automatically scanned for packages by the command-line tools. For
  5176. instance, when running @code{guix install emacs}, all the @code{(gnu
  5177. packages @dots{})} modules are scanned until one that exports a package
  5178. object whose name is @code{emacs} is found. This package search
  5179. facility is implemented in the @code{(gnu packages)} module.
  5180. @cindex customization, of packages
  5181. @cindex package module search path
  5182. Users can store package definitions in modules with different
  5183. names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
  5184. name and module name must match. For instance, the @code{(my-packages
  5185. emacs)} module must be stored in a @file{my-packages/emacs.scm} file
  5186. relative to the load path specified with @option{--load-path} or
  5187. @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
  5188. guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
  5189. these package definitions visible to the user interfaces:
  5190. @enumerate
  5191. @item
  5192. By adding the directory containing your package modules to the search path
  5193. with the @code{-L} flag of @command{guix package} and other commands
  5194. (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
  5195. environment variable described below.
  5196. @item
  5197. By defining a @dfn{channel} and configuring @command{guix pull} so that it
  5198. pulls from it. A channel is essentially a Git repository containing package
  5199. modules. @xref{Channels}, for more information on how to define and use
  5200. channels.
  5201. @end enumerate
  5202. @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
  5203. @defvr {Environment Variable} GUIX_PACKAGE_PATH
  5204. This is a colon-separated list of directories to search for additional
  5205. package modules. Directories listed in this variable take precedence
  5206. over the own modules of the distribution.
  5207. @end defvr
  5208. The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
  5209. each package is built based solely on other packages in the
  5210. distribution. The root of this dependency graph is a small set of
  5211. @dfn{bootstrap binaries}, provided by the @code{(gnu packages
  5212. bootstrap)} module. For more information on bootstrapping,
  5213. @pxref{Bootstrapping}.
  5214. @node Defining Packages
  5215. @section Defining Packages
  5216. The high-level interface to package definitions is implemented in the
  5217. @code{(guix packages)} and @code{(guix build-system)} modules. As an
  5218. example, the package definition, or @dfn{recipe}, for the GNU Hello
  5219. package looks like this:
  5220. @lisp
  5221. (define-module (gnu packages hello)
  5222. #:use-module (guix packages)
  5223. #:use-module (guix download)
  5224. #:use-module (guix build-system gnu)
  5225. #:use-module (guix licenses)
  5226. #:use-module (gnu packages gawk))
  5227. (define-public hello
  5228. (package
  5229. (name "hello")
  5230. (version "2.10")
  5231. (source (origin
  5232. (method url-fetch)
  5233. (uri (string-append "mirror://gnu/hello/hello-" version
  5234. ".tar.gz"))
  5235. (sha256
  5236. (base32
  5237. "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
  5238. (build-system gnu-build-system)
  5239. (arguments '(#:configure-flags '("--enable-silent-rules")))
  5240. (inputs `(("gawk" ,gawk)))
  5241. (synopsis "Hello, GNU world: An example GNU package")
  5242. (description "Guess what GNU Hello prints!")
  5243. (home-page "https://www.gnu.org/software/hello/")
  5244. (license gpl3+)))
  5245. @end lisp
  5246. @noindent
  5247. Without being a Scheme expert, the reader may have guessed the meaning
  5248. of the various fields here. This expression binds the variable
  5249. @code{hello} to a @code{<package>} object, which is essentially a record
  5250. (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
  5251. This package object can be inspected using procedures found in the
  5252. @code{(guix packages)} module; for instance, @code{(package-name hello)}
  5253. returns---surprise!---@code{"hello"}.
  5254. With luck, you may be able to import part or all of the definition of
  5255. the package you are interested in from another repository, using the
  5256. @code{guix import} command (@pxref{Invoking guix import}).
  5257. In the example above, @code{hello} is defined in a module of its own,
  5258. @code{(gnu packages hello)}. Technically, this is not strictly
  5259. necessary, but it is convenient to do so: all the packages defined in
  5260. modules under @code{(gnu packages @dots{})} are automatically known to
  5261. the command-line tools (@pxref{Package Modules}).
  5262. There are a few points worth noting in the above package definition:
  5263. @itemize
  5264. @item
  5265. The @code{source} field of the package is an @code{<origin>} object
  5266. (@pxref{origin Reference}, for the complete reference).
  5267. Here, the @code{url-fetch} method from @code{(guix download)} is used,
  5268. meaning that the source is a file to be downloaded over FTP or HTTP.
  5269. The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
  5270. the GNU mirrors defined in @code{(guix download)}.
  5271. The @code{sha256} field specifies the expected SHA256 hash of the file
  5272. being downloaded. It is mandatory, and allows Guix to check the
  5273. integrity of the file. The @code{(base32 @dots{})} form introduces the
  5274. base32 representation of the hash. You can obtain this information with
  5275. @code{guix download} (@pxref{Invoking guix download}) and @code{guix
  5276. hash} (@pxref{Invoking guix hash}).
  5277. @cindex patches
  5278. When needed, the @code{origin} form can also have a @code{patches} field
  5279. listing patches to be applied, and a @code{snippet} field giving a
  5280. Scheme expression to modify the source code.
  5281. @item
  5282. @cindex GNU Build System
  5283. The @code{build-system} field specifies the procedure to build the
  5284. package (@pxref{Build Systems}). Here, @code{gnu-build-system}
  5285. represents the familiar GNU Build System, where packages may be
  5286. configured, built, and installed with the usual @code{./configure &&
  5287. make && make check && make install} command sequence.
  5288. When you start packaging non-trivial software, you may need tools to
  5289. manipulate those build phases, manipulate files, and so on. @xref{Build
  5290. Utilities}, for more on this.
  5291. @item
  5292. The @code{arguments} field specifies options for the build system
  5293. (@pxref{Build Systems}). Here it is interpreted by
  5294. @code{gnu-build-system} as a request run @file{configure} with the
  5295. @option{--enable-silent-rules} flag.
  5296. @cindex quote
  5297. @cindex quoting
  5298. @findex '
  5299. @findex quote
  5300. What about these quote (@code{'}) characters? They are Scheme syntax to
  5301. introduce a literal list; @code{'} is synonymous with @code{quote}.
  5302. @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
  5303. for details. Here the value of the @code{arguments} field is a list of
  5304. arguments passed to the build system down the road, as with @code{apply}
  5305. (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
  5306. Manual}).
  5307. The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
  5308. (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
  5309. @code{#:configure-flags} is a keyword used to pass a keyword argument
  5310. to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
  5311. Reference Manual}).
  5312. @item
  5313. The @code{inputs} field specifies inputs to the build process---i.e.,
  5314. build-time or run-time dependencies of the package. Here, we define an
  5315. input called @code{"gawk"} whose value is that of the @code{gawk}
  5316. variable; @code{gawk} is itself bound to a @code{<package>} object.
  5317. @cindex backquote (quasiquote)
  5318. @findex `
  5319. @findex quasiquote
  5320. @cindex comma (unquote)
  5321. @findex ,
  5322. @findex unquote
  5323. @findex ,@@
  5324. @findex unquote-splicing
  5325. Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
  5326. us to introduce a literal list in the @code{inputs} field, while
  5327. @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
  5328. value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
  5329. Reference Manual}).
  5330. Note that GCC, Coreutils, Bash, and other essential tools do not need to
  5331. be specified as inputs here. Instead, @code{gnu-build-system} takes care
  5332. of ensuring that they are present (@pxref{Build Systems}).
  5333. However, any other dependencies need to be specified in the
  5334. @code{inputs} field. Any dependency not specified here will simply be
  5335. unavailable to the build process, possibly leading to a build failure.
  5336. @end itemize
  5337. @xref{package Reference}, for a full description of possible fields.
  5338. Once a package definition is in place, the
  5339. package may actually be built using the @code{guix build} command-line
  5340. tool (@pxref{Invoking guix build}), troubleshooting any build failures
  5341. you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
  5342. package definition using the @command{guix edit} command
  5343. (@pxref{Invoking guix edit}).
  5344. @xref{Packaging Guidelines}, for
  5345. more information on how to test package definitions, and
  5346. @ref{Invoking guix lint}, for information on how to check a definition
  5347. for style conformance.
  5348. @vindex GUIX_PACKAGE_PATH
  5349. Lastly, @pxref{Channels}, for information
  5350. on how to extend the distribution by adding your own package definitions
  5351. in a ``channel''.
  5352. Finally, updating the package definition to a new upstream version
  5353. can be partly automated by the @command{guix refresh} command
  5354. (@pxref{Invoking guix refresh}).
  5355. Behind the scenes, a derivation corresponding to the @code{<package>}
  5356. object is first computed by the @code{package-derivation} procedure.
  5357. That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
  5358. The build actions it prescribes may then be realized by using the
  5359. @code{build-derivations} procedure (@pxref{The Store}).
  5360. @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
  5361. Return the @code{<derivation>} object of @var{package} for @var{system}
  5362. (@pxref{Derivations}).
  5363. @var{package} must be a valid @code{<package>} object, and @var{system}
  5364. must be a string denoting the target system type---e.g.,
  5365. @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
  5366. must be a connection to the daemon, which operates on the store
  5367. (@pxref{The Store}).
  5368. @end deffn
  5369. @noindent
  5370. @cindex cross-compilation
  5371. Similarly, it is possible to compute a derivation that cross-builds a
  5372. package for some other system:
  5373. @deffn {Scheme Procedure} package-cross-derivation @var{store} @
  5374. @var{package} @var{target} [@var{system}]
  5375. Return the @code{<derivation>} object of @var{package} cross-built from
  5376. @var{system} to @var{target}.
  5377. @var{target} must be a valid GNU triplet denoting the target hardware
  5378. and operating system, such as @code{"aarch64-linux-gnu"}
  5379. (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
  5380. @end deffn
  5381. Once you have package definitions, you can easily define @emph{variants}
  5382. of those packages. @xref{Defining Package Variants}, for more on that.
  5383. @menu
  5384. * package Reference:: The package data type.
  5385. * origin Reference:: The origin data type.
  5386. @end menu
  5387. @node package Reference
  5388. @subsection @code{package} Reference
  5389. This section summarizes all the options available in @code{package}
  5390. declarations (@pxref{Defining Packages}).
  5391. @deftp {Data Type} package
  5392. This is the data type representing a package recipe.
  5393. @table @asis
  5394. @item @code{name}
  5395. The name of the package, as a string.
  5396. @item @code{version}
  5397. The version of the package, as a string.
  5398. @item @code{source}
  5399. An object telling how the source code for the package should be
  5400. acquired. Most of the time, this is an @code{origin} object, which
  5401. denotes a file fetched from the Internet (@pxref{origin Reference}). It
  5402. can also be any other ``file-like'' object such as a @code{local-file},
  5403. which denotes a file from the local file system (@pxref{G-Expressions,
  5404. @code{local-file}}).
  5405. @item @code{build-system}
  5406. The build system that should be used to build the package (@pxref{Build
  5407. Systems}).
  5408. @item @code{arguments} (default: @code{'()})
  5409. The arguments that should be passed to the build system. This is a
  5410. list, typically containing sequential keyword-value pairs.
  5411. @item @code{inputs} (default: @code{'()})
  5412. @itemx @code{native-inputs} (default: @code{'()})
  5413. @itemx @code{propagated-inputs} (default: @code{'()})
  5414. @cindex inputs, of packages
  5415. These fields list dependencies of the package. Each one is a list of
  5416. tuples, where each tuple has a label for the input (a string) as its
  5417. first element, a package, origin, or derivation as its second element,
  5418. and optionally the name of the output thereof that should be used, which
  5419. defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
  5420. more on package outputs). For example, the list below specifies three
  5421. inputs:
  5422. @lisp
  5423. `(("libffi" ,libffi)
  5424. ("libunistring" ,libunistring)
  5425. ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
  5426. @end lisp
  5427. @cindex cross compilation, package dependencies
  5428. The distinction between @code{native-inputs} and @code{inputs} is
  5429. necessary when considering cross-compilation. When cross-compiling,
  5430. dependencies listed in @code{inputs} are built for the @emph{target}
  5431. architecture; conversely, dependencies listed in @code{native-inputs}
  5432. are built for the architecture of the @emph{build} machine.
  5433. @code{native-inputs} is typically used to list tools needed at
  5434. build time, but not at run time, such as Autoconf, Automake, pkg-config,
  5435. Gettext, or Bison. @command{guix lint} can report likely mistakes in
  5436. this area (@pxref{Invoking guix lint}).
  5437. @anchor{package-propagated-inputs}
  5438. Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
  5439. specified packages will be automatically installed to profiles
  5440. (@pxref{Features, the role of profiles in Guix}) alongside the package
  5441. they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
  5442. package}}, for information on how @command{guix package} deals with
  5443. propagated inputs).
  5444. For example this is necessary when packaging a C/C++ library that needs
  5445. headers of another library to compile, or when a pkg-config file refers
  5446. to another one @i{via} its @code{Requires} field.
  5447. Another example where @code{propagated-inputs} is useful is for languages
  5448. that lack a facility to record the run-time search path akin to the
  5449. @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
  5450. more. When packaging libraries written in those languages, ensure they
  5451. can find library code they depend on at run time by listing run-time
  5452. dependencies in @code{propagated-inputs} rather than @code{inputs}.
  5453. @item @code{outputs} (default: @code{'("out")})
  5454. The list of output names of the package. @xref{Packages with Multiple
  5455. Outputs}, for typical uses of additional outputs.
  5456. @item @code{native-search-paths} (default: @code{'()})
  5457. @itemx @code{search-paths} (default: @code{'()})
  5458. A list of @code{search-path-specification} objects describing
  5459. search-path environment variables honored by the package.
  5460. @item @code{replacement} (default: @code{#f})
  5461. This must be either @code{#f} or a package object that will be used as a
  5462. @dfn{replacement} for this package. @xref{Security Updates, grafts},
  5463. for details.
  5464. @item @code{synopsis}
  5465. A one-line description of the package.
  5466. @item @code{description}
  5467. A more elaborate description of the package.
  5468. @item @code{license}
  5469. @cindex license, of packages
  5470. The license of the package; a value from @code{(guix licenses)},
  5471. or a list of such values.
  5472. @item @code{home-page}
  5473. The URL to the home-page of the package, as a string.
  5474. @item @code{supported-systems} (default: @code{%supported-systems})
  5475. The list of systems supported by the package, as strings of the form
  5476. @code{architecture-kernel}, for example @code{"x86_64-linux"}.
  5477. @item @code{location} (default: source location of the @code{package} form)
  5478. The source location of the package. It is useful to override this when
  5479. inheriting from another package, in which case this field is not
  5480. automatically corrected.
  5481. @end table
  5482. @end deftp
  5483. @deffn {Scheme Syntax} this-package
  5484. When used in the @emph{lexical scope} of a package field definition, this
  5485. identifier resolves to the package being defined.
  5486. The example below shows how to add a package as a native input of itself when
  5487. cross-compiling:
  5488. @lisp
  5489. (package
  5490. (name "guile")
  5491. ;; ...
  5492. ;; When cross-compiled, Guile, for example, depends on
  5493. ;; a native version of itself. Add it here.
  5494. (native-inputs (if (%current-target-system)
  5495. `(("self" ,this-package))
  5496. '())))
  5497. @end lisp
  5498. It is an error to refer to @code{this-package} outside a package definition.
  5499. @end deffn
  5500. Because packages are regular Scheme objects that capture a complete
  5501. dependency graph and associated build procedures, it is often useful to
  5502. write procedures that take a package and return a modified version
  5503. thereof according to some parameters. Below are a few examples.
  5504. @cindex tool chain, choosing a package's tool chain
  5505. @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
  5506. Return a variant of @var{package} that uses @var{toolchain} instead of
  5507. the default GNU C/C++ toolchain. @var{toolchain} must be a list of
  5508. inputs (label/package tuples) providing equivalent functionality, such
  5509. as the @code{gcc-toolchain} package.
  5510. The example below returns a variant of the @code{hello} package built
  5511. with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
  5512. GNU C Library) instead of the default tool chain:
  5513. @lisp
  5514. (let ((toolchain (specification->package "gcc-toolchain@@10")))
  5515. (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
  5516. @end lisp
  5517. The build tool chain is part of the @dfn{implicit inputs} of
  5518. packages---it's usually not listed as part of the various ``inputs''
  5519. fields and is instead pulled in by the build system. Consequently, this
  5520. procedure works by changing the build system of @var{package} so that it
  5521. pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
  5522. for more on build systems.
  5523. @end deffn
  5524. @node origin Reference
  5525. @subsection @code{origin} Reference
  5526. This section documents @dfn{origins}. An @code{origin} declaration
  5527. specifies data that must be ``produced''---downloaded, usually---and
  5528. whose content hash is known in advance. Origins are primarily used to
  5529. represent the source code of packages (@pxref{Defining Packages}). For
  5530. that reason, the @code{origin} form allows you to declare patches to
  5531. apply to the original source code as well as code snippets to modify it.
  5532. @deftp {Data Type} origin
  5533. This is the data type representing a source code origin.
  5534. @table @asis
  5535. @item @code{uri}
  5536. An object containing the URI of the source. The object type depends on
  5537. the @code{method} (see below). For example, when using the
  5538. @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
  5539. values are: a URL represented as a string, or a list thereof.
  5540. @cindex fixed-output derivations, for download
  5541. @item @code{method}
  5542. A monadic procedure that handles the given URI@. The procedure must
  5543. accept at least three arguments: the value of the @code{uri} field and
  5544. the hash algorithm and hash value specified by the @code{hash} field.
  5545. It must return a store item or a derivation in the store monad
  5546. (@pxref{The Store Monad}); most methods return a fixed-output derivation
  5547. (@pxref{Derivations}).
  5548. Commonly used methods include @code{url-fetch}, which fetches data from
  5549. a URL, and @code{git-fetch}, which fetches data from a Git repository
  5550. (see below).
  5551. @item @code{sha256}
  5552. A bytevector containing the SHA-256 hash of the source. This is
  5553. equivalent to providing a @code{content-hash} SHA256 object in the
  5554. @code{hash} field described below.
  5555. @item @code{hash}
  5556. The @code{content-hash} object of the source---see below for how to use
  5557. @code{content-hash}.
  5558. You can obtain this information using @code{guix download}
  5559. (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
  5560. guix hash}).
  5561. @item @code{file-name} (default: @code{#f})
  5562. The file name under which the source code should be saved. When this is
  5563. @code{#f}, a sensible default value will be used in most cases. In case
  5564. the source is fetched from a URL, the file name from the URL will be
  5565. used. For version control checkouts, it is recommended to provide the
  5566. file name explicitly because the default is not very descriptive.
  5567. @item @code{patches} (default: @code{'()})
  5568. A list of file names, origins, or file-like objects (@pxref{G-Expressions,
  5569. file-like objects}) pointing to patches to be applied to the source.
  5570. This list of patches must be unconditional. In particular, it cannot
  5571. depend on the value of @code{%current-system} or
  5572. @code{%current-target-system}.
  5573. @item @code{snippet} (default: @code{#f})
  5574. A G-expression (@pxref{G-Expressions}) or S-expression that will be run
  5575. in the source directory. This is a convenient way to modify the source,
  5576. sometimes more convenient than a patch.
  5577. @item @code{patch-flags} (default: @code{'("-p1")})
  5578. A list of command-line flags that should be passed to the @code{patch}
  5579. command.
  5580. @item @code{patch-inputs} (default: @code{#f})
  5581. Input packages or derivations to the patching process. When this is
  5582. @code{#f}, the usual set of inputs necessary for patching are provided,
  5583. such as GNU@tie{}Patch.
  5584. @item @code{modules} (default: @code{'()})
  5585. A list of Guile modules that should be loaded during the patching
  5586. process and while running the code in the @code{snippet} field.
  5587. @item @code{patch-guile} (default: @code{#f})
  5588. The Guile package that should be used in the patching process. When
  5589. this is @code{#f}, a sensible default is used.
  5590. @end table
  5591. @end deftp
  5592. @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
  5593. Construct a content hash object for the given @var{algorithm}, and with
  5594. @var{value} as its hash value. When @var{algorithm} is omitted, assume
  5595. it is @code{sha256}.
  5596. @var{value} can be a literal string, in which case it is base32-decoded,
  5597. or it can be a bytevector.
  5598. The following forms are all equivalent:
  5599. @lisp
  5600. (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
  5601. (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
  5602. sha256)
  5603. (content-hash (base32
  5604. "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
  5605. (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
  5606. sha256)
  5607. @end lisp
  5608. Technically, @code{content-hash} is currently implemented as a macro.
  5609. It performs sanity checks at macro-expansion time, when possible, such
  5610. as ensuring that @var{value} has the right size for @var{algorithm}.
  5611. @end deftp
  5612. As we have seen above, how exactly the data an origin refers to is
  5613. retrieved is determined by its @code{method} field. The @code{(guix
  5614. download)} module provides the most common method, @code{url-fetch},
  5615. described below.
  5616. @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
  5617. [name] [#:executable? #f]
  5618. Return a fixed-output derivation that fetches data from @var{url} (a
  5619. string, or a list of strings denoting alternate URLs), which is expected
  5620. to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
  5621. the file name is the base name of URL; optionally, @var{name} can
  5622. specify a different file name. When @var{executable?} is true, make the
  5623. downloaded file executable.
  5624. When one of the URL starts with @code{mirror://}, then its host part is
  5625. interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
  5626. Alternatively, when URL starts with @code{file://}, return the
  5627. corresponding file name in the store.
  5628. @end deffn
  5629. Likewise, the @code{(guix git-download)} module defines the
  5630. @code{git-fetch} origin method, which fetches data from a Git version
  5631. control repository, and the @code{git-reference} data type to describe
  5632. the repository and revision to fetch.
  5633. @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
  5634. Return a fixed-output derivation that fetches @var{ref}, a
  5635. @code{<git-reference>} object. The output is expected to have recursive
  5636. hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
  5637. the file name, or a generic name if @code{#f}.
  5638. @end deffn
  5639. @deftp {Data Type} git-reference
  5640. This data type represents a Git reference for @code{git-fetch} to
  5641. retrieve.
  5642. @table @asis
  5643. @item @code{url}
  5644. The URL of the Git repository to clone.
  5645. @item @code{commit}
  5646. This string denotes either the commit to fetch (a hexadecimal string,
  5647. either the full SHA1 commit or a ``short'' commit string; the latter is
  5648. not recommended) or the tag to fetch.
  5649. @item @code{recursive?} (default: @code{#f})
  5650. This Boolean indicates whether to recursively fetch Git sub-modules.
  5651. @end table
  5652. The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
  5653. repository:
  5654. @lisp
  5655. (git-reference
  5656. (url "https://git.savannah.gnu.org/git/hello.git")
  5657. (commit "v2.10"))
  5658. @end lisp
  5659. This is equivalent to the reference below, which explicitly names the
  5660. commit:
  5661. @lisp
  5662. (git-reference
  5663. (url "https://git.savannah.gnu.org/git/hello.git")
  5664. (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
  5665. @end lisp
  5666. @end deftp
  5667. For Mercurial repositories, the module @code{(guix hg-download)} defines
  5668. the @code{hg-fetch} origin method and @code{hg-reference} data type for
  5669. support of the Mercurial version control system.
  5670. @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
  5671. [name]
  5672. Return a fixed-output derivation that fetches @var{ref}, a
  5673. @code{<hg-reference>} object. The output is expected to have recursive
  5674. hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
  5675. the file name, or a generic name if @code{#false}.
  5676. @end deffn
  5677. @node Defining Package Variants
  5678. @section Defining Package Variants
  5679. @cindex customizing packages
  5680. @cindex variants, of packages
  5681. One of the nice things with Guix is that, given a package definition,
  5682. you can easily @emph{derive} variants of that package---for a different
  5683. upstream version, with different dependencies, different compilation
  5684. options, and so on. Some of these custom packages can be defined
  5685. straight from the command line (@pxref{Package Transformation Options}).
  5686. This section describes how to define package variants in code. This can
  5687. be useful in ``manifests'' (@pxref{profile-manifest,
  5688. @option{--manifest}}) and in your own package collection
  5689. (@pxref{Creating a Channel}), among others!
  5690. @cindex inherit, for package definitions
  5691. As discussed earlier, packages are first-class objects in the Scheme
  5692. language. The @code{(guix packages)} module provides the @code{package}
  5693. construct to define new package objects (@pxref{package Reference}).
  5694. The easiest way to define a package variant is using the @code{inherit}
  5695. keyword together with @code{package}. This allows you to inherit from a
  5696. package definition while overriding the fields you want.
  5697. For example, given the @code{hello} variable, which contains a
  5698. definition for the current version of GNU@tie{}Hello, here's how you
  5699. would define a variant for version 2.2 (released in 2006, it's
  5700. vintage!):
  5701. @lisp
  5702. (use-modules (gnu packages base)) ;for 'hello'
  5703. (define hello-2.2
  5704. (package
  5705. (inherit hello)
  5706. (version "2.2")
  5707. (source (origin
  5708. (method url-fetch)
  5709. (uri (string-append "mirror://gnu/hello/hello-" version
  5710. ".tar.gz"))
  5711. (sha256
  5712. (base32
  5713. "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
  5714. @end lisp
  5715. The example above corresponds to what the @option{--with-source} package
  5716. transformation option does. Essentially @code{hello-2.2} preserves all
  5717. the fields of @code{hello}, except @code{version} and @code{source},
  5718. which it overrides. Note that the original @code{hello} variable is
  5719. still there, in the @code{(gnu packages base)} module, unchanged. When
  5720. you define a custom package like this, you are really @emph{adding} a
  5721. new package definition; the original one remains available.
  5722. You can just as well define variants with a different set of
  5723. dependencies than the original package. For example, the default
  5724. @code{gdb} package depends on @code{guile}, but since that is an
  5725. optional dependency, you can define a variant that removes that
  5726. dependency like so:
  5727. @lisp
  5728. (use-modules (gnu packages gdb) ;for 'gdb'
  5729. (srfi srfi-1)) ;for 'alist-delete'
  5730. (define gdb-sans-guile
  5731. (package
  5732. (inherit gdb)
  5733. (inputs (alist-delete "guile"
  5734. (package-inputs gdb)))))
  5735. @end lisp
  5736. The @code{alist-delete} call above removes the tuple from the
  5737. @code{inputs} field that has @code{"guile"} as its first element
  5738. (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
  5739. Manual}).
  5740. In some cases, you may find it useful to write functions
  5741. (``procedures'', in Scheme parlance) that return a package based on some
  5742. parameters. For example, consider the @code{luasocket} library for the
  5743. Lua programming language. We want to create @code{luasocket} packages
  5744. for major versions of Lua. One way to do that is to define a procedure
  5745. that takes a Lua package and returns a @code{luasocket} package that
  5746. depends on it:
  5747. @lisp
  5748. (define (make-lua-socket name lua)
  5749. ;; Return a luasocket package built with LUA.
  5750. (package
  5751. (name name)
  5752. (version "3.0")
  5753. ;; several fields omitted
  5754. (inputs
  5755. `(("lua" ,lua)))
  5756. (synopsis "Socket library for Lua")))
  5757. (define-public lua5.1-socket
  5758. (make-lua-socket "lua5.1-socket" lua-5.1))
  5759. (define-public lua5.2-socket
  5760. (make-lua-socket "lua5.2-socket" lua-5.2))
  5761. @end lisp
  5762. Here we have defined packages @code{lua5.1-socket} and
  5763. @code{lua5.2-socket} by calling @code{make-lua-socket} with different
  5764. arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
  5765. more info on procedures. Having top-level public definitions for these
  5766. two packages means that they can be referred to from the command line
  5767. (@pxref{Package Modules}).
  5768. @cindex package transformations
  5769. These are pretty simple package variants. As a convenience, the
  5770. @code{(guix transformations)} module provides a high-level interface
  5771. that directly maps to the more sophisticated package transformation
  5772. options (@pxref{Package Transformation Options}):
  5773. @deffn {Scheme Procedure} options->transformation @var{opts}
  5774. Return a procedure that, when passed an object to build (package,
  5775. derivation, etc.), applies the transformations specified by @var{opts} and returns
  5776. the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
  5777. @lisp
  5778. ((with-branch . "guile-gcrypt=master")
  5779. (without-tests . "libgcrypt"))
  5780. @end lisp
  5781. Each symbol names a transformation and the corresponding string is an argument
  5782. to that transformation.
  5783. @end deffn
  5784. For instance, a manifest equivalent to this command:
  5785. @example
  5786. guix build guix \
  5787. --with-branch=guile-gcrypt=master \
  5788. --with-debug-info=zlib
  5789. @end example
  5790. @noindent
  5791. ... would look like this:
  5792. @lisp
  5793. (use-modules (guix transformations))
  5794. (define transform
  5795. ;; The package transformation procedure.
  5796. (options->transformation
  5797. '((with-branch . "guile-gcrypt=master")
  5798. (with-debug-info . "zlib"))))
  5799. (packages->manifest
  5800. (list (transform (specification->package "guix"))))
  5801. @end lisp
  5802. @cindex input rewriting
  5803. @cindex dependency graph rewriting
  5804. The @code{options->transformation} procedure is convenient, but it's
  5805. perhaps also not as flexible as you may like. How is it implemented?
  5806. The astute reader probably noticed that most package transformation
  5807. options go beyond the superficial changes shown in the first examples of
  5808. this section: they involve @dfn{input rewriting}, whereby the dependency
  5809. graph of a package is rewritten by replacing specific inputs by others.
  5810. Dependency graph rewriting, for the purposes of swapping packages in the
  5811. graph, is what the @code{package-input-rewriting} procedure in
  5812. @code{(guix packages)} implements.
  5813. @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
  5814. [@var{rewrite-name}] [#:deep? #t]
  5815. Return a procedure that, when passed a package, replaces its direct and
  5816. indirect dependencies, including implicit inputs when @var{deep?} is
  5817. true, according to @var{replacements}. @var{replacements} is a list of
  5818. package pairs; the first element of each pair is the package to replace,
  5819. and the second one is the replacement.
  5820. Optionally, @var{rewrite-name} is a one-argument procedure that takes
  5821. the name of a package and returns its new name after rewrite.
  5822. @end deffn
  5823. @noindent
  5824. Consider this example:
  5825. @lisp
  5826. (define libressl-instead-of-openssl
  5827. ;; This is a procedure to replace OPENSSL by LIBRESSL,
  5828. ;; recursively.
  5829. (package-input-rewriting `((,openssl . ,libressl))))
  5830. (define git-with-libressl
  5831. (libressl-instead-of-openssl git))
  5832. @end lisp
  5833. @noindent
  5834. Here we first define a rewriting procedure that replaces @var{openssl}
  5835. with @var{libressl}. Then we use it to define a @dfn{variant} of the
  5836. @var{git} package that uses @var{libressl} instead of @var{openssl}.
  5837. This is exactly what the @option{--with-input} command-line option does
  5838. (@pxref{Package Transformation Options, @option{--with-input}}).
  5839. The following variant of @code{package-input-rewriting} can match packages to
  5840. be replaced by name rather than by identity.
  5841. @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
  5842. Return a procedure that, given a package, applies the given
  5843. @var{replacements} to all the package graph, including implicit inputs
  5844. unless @var{deep?} is false. @var{replacements} is a list of
  5845. spec/procedures pair; each spec is a package specification such as
  5846. @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
  5847. package and returns a replacement for that package.
  5848. @end deffn
  5849. The example above could be rewritten this way:
  5850. @lisp
  5851. (define libressl-instead-of-openssl
  5852. ;; Replace all the packages called "openssl" with LibreSSL.
  5853. (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
  5854. @end lisp
  5855. The key difference here is that, this time, packages are matched by spec and
  5856. not by identity. In other words, any package in the graph that is called
  5857. @code{openssl} will be replaced.
  5858. A more generic procedure to rewrite a package dependency graph is
  5859. @code{package-mapping}: it supports arbitrary changes to nodes in the
  5860. graph.
  5861. @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
  5862. Return a procedure that, given a package, applies @var{proc} to all the packages
  5863. depended on and returns the resulting package. The procedure stops recursion
  5864. when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
  5865. applied to implicit inputs as well.
  5866. @end deffn
  5867. @node Build Systems
  5868. @section Build Systems
  5869. @cindex build system
  5870. Each package definition specifies a @dfn{build system} and arguments for
  5871. that build system (@pxref{Defining Packages}). This @code{build-system}
  5872. field represents the build procedure of the package, as well as implicit
  5873. dependencies of that build procedure.
  5874. Build systems are @code{<build-system>} objects. The interface to
  5875. create and manipulate them is provided by the @code{(guix build-system)}
  5876. module, and actual build systems are exported by specific modules.
  5877. @cindex bag (low-level package representation)
  5878. Under the hood, build systems first compile package objects to
  5879. @dfn{bags}. A @dfn{bag} is like a package, but with less
  5880. ornamentation---in other words, a bag is a lower-level representation of
  5881. a package, which includes all the inputs of that package, including some
  5882. that were implicitly added by the build system. This intermediate
  5883. representation is then compiled to a derivation (@pxref{Derivations}).
  5884. The @code{package-with-c-toolchain} is an example of a way to change the
  5885. implicit inputs that a package's build system pulls in (@pxref{package
  5886. Reference, @code{package-with-c-toolchain}}).
  5887. Build systems accept an optional list of @dfn{arguments}. In package
  5888. definitions, these are passed @i{via} the @code{arguments} field
  5889. (@pxref{Defining Packages}). They are typically keyword arguments
  5890. (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
  5891. Guile Reference Manual}). The value of these arguments is usually
  5892. evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
  5893. by the daemon (@pxref{Derivations}).
  5894. The main build system is @code{gnu-build-system}, which implements the
  5895. standard build procedure for GNU and many other packages. It
  5896. is provided by the @code{(guix build-system gnu)} module.
  5897. @defvr {Scheme Variable} gnu-build-system
  5898. @code{gnu-build-system} represents the GNU Build System, and variants
  5899. thereof (@pxref{Configuration, configuration and makefile conventions,,
  5900. standards, GNU Coding Standards}).
  5901. @cindex build phases
  5902. In a nutshell, packages using it are configured, built, and installed with
  5903. the usual @code{./configure && make && make check && make install}
  5904. command sequence. In practice, a few additional steps are often needed.
  5905. All these steps are split up in separate @dfn{phases},
  5906. notably@footnote{Please see the @code{(guix build gnu-build-system)}
  5907. modules for more details about the build phases.}:
  5908. @table @code
  5909. @item unpack
  5910. Unpack the source tarball, and change the current directory to the
  5911. extracted source tree. If the source is actually a directory, copy it
  5912. to the build tree, and enter that directory.
  5913. @item patch-source-shebangs
  5914. Patch shebangs encountered in source files so they refer to the right
  5915. store file names. For instance, this changes @code{#!/bin/sh} to
  5916. @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
  5917. @item configure
  5918. Run the @file{configure} script with a number of default options, such
  5919. as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
  5920. by the @code{#:configure-flags} argument.
  5921. @item build
  5922. Run @code{make} with the list of flags specified with
  5923. @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
  5924. (the default), build with @code{make -j}.
  5925. @item check
  5926. Run @code{make check}, or some other target specified with
  5927. @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
  5928. @code{#:parallel-tests?} argument is true (the default), run @code{make
  5929. check -j}.
  5930. @item install
  5931. Run @code{make install} with the flags listed in @code{#:make-flags}.
  5932. @item patch-shebangs
  5933. Patch shebangs on the installed executable files.
  5934. @item strip
  5935. Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
  5936. is false), copying them to the @code{debug} output when available
  5937. (@pxref{Installing Debugging Files}).
  5938. @end table
  5939. @vindex %standard-phases
  5940. The build-side module @code{(guix build gnu-build-system)} defines
  5941. @code{%standard-phases} as the default list of build phases.
  5942. @code{%standard-phases} is a list of symbol/procedure pairs, where the
  5943. procedure implements the actual phase.
  5944. @xref{Build Phases}, for more info on build phases and ways to customize
  5945. them.
  5946. In addition, this build system ensures that the ``standard'' environment
  5947. for GNU packages is available. This includes tools such as GCC, libc,
  5948. Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
  5949. build-system gnu)} module for a complete list). We call these the
  5950. @dfn{implicit inputs} of a package, because package definitions do not
  5951. have to mention them.
  5952. @end defvr
  5953. Other @code{<build-system>} objects are defined to support other
  5954. conventions and tools used by free software packages. They inherit most
  5955. of @code{gnu-build-system}, and differ mainly in the set of inputs
  5956. implicitly added to the build process, and in the list of phases
  5957. executed. Some of these build systems are listed below.
  5958. @defvr {Scheme Variable} ant-build-system
  5959. This variable is exported by @code{(guix build-system ant)}. It
  5960. implements the build procedure for Java packages that can be built with
  5961. @url{https://ant.apache.org/, Ant build tool}.
  5962. It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
  5963. provided by the @code{icedtea} package to the set of inputs. Different
  5964. packages can be specified with the @code{#:ant} and @code{#:jdk}
  5965. parameters, respectively.
  5966. When the original package does not provide a suitable Ant build file,
  5967. the parameter @code{#:jar-name} can be used to generate a minimal Ant
  5968. build file @file{build.xml} with tasks to build the specified jar
  5969. archive. In this case the parameter @code{#:source-dir} can be used to
  5970. specify the source sub-directory, defaulting to ``src''.
  5971. The @code{#:main-class} parameter can be used with the minimal ant
  5972. buildfile to specify the main class of the resulting jar. This makes the
  5973. jar file executable. The @code{#:test-include} parameter can be used to
  5974. specify the list of junit tests to run. It defaults to
  5975. @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
  5976. disable some tests. It defaults to @code{(list "**/Abstract*.java")},
  5977. because abstract classes cannot be run as tests.
  5978. The parameter @code{#:build-target} can be used to specify the Ant task
  5979. that should be run during the @code{build} phase. By default the
  5980. ``jar'' task will be run.
  5981. @end defvr
  5982. @defvr {Scheme Variable} android-ndk-build-system
  5983. @cindex Android distribution
  5984. @cindex Android NDK build system
  5985. This variable is exported by @code{(guix build-system android-ndk)}. It
  5986. implements a build procedure for Android NDK (native development kit)
  5987. packages using a Guix-specific build process.
  5988. The build system assumes that packages install their public interface
  5989. (header) files to the subdirectory @file{include} of the @code{out} output and
  5990. their libraries to the subdirectory @file{lib} the @code{out} output.
  5991. It's also assumed that the union of all the dependencies of a package
  5992. has no conflicting files.
  5993. For the time being, cross-compilation is not supported - so right now
  5994. the libraries and header files are assumed to be host tools.
  5995. @end defvr
  5996. @defvr {Scheme Variable} asdf-build-system/source
  5997. @defvrx {Scheme Variable} asdf-build-system/sbcl
  5998. @defvrx {Scheme Variable} asdf-build-system/ecl
  5999. These variables, exported by @code{(guix build-system asdf)}, implement
  6000. build procedures for Common Lisp packages using
  6001. @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
  6002. definition facility for Common Lisp programs and libraries.
  6003. The @code{asdf-build-system/source} system installs the packages in
  6004. source form, and can be loaded using any common lisp implementation, via
  6005. ASDF@. The others, such as @code{asdf-build-system/sbcl}, install binary
  6006. systems in the format which a particular implementation understands.
  6007. These build systems can also be used to produce executable programs, or
  6008. lisp images which contain a set of packages pre-loaded.
  6009. The build system uses naming conventions. For binary packages, the
  6010. package name should be prefixed with the lisp implementation, such as
  6011. @code{sbcl-} for @code{asdf-build-system/sbcl}.
  6012. Additionally, the corresponding source package should be labeled using
  6013. the same convention as python packages (see @ref{Python Modules}), using
  6014. the @code{cl-} prefix.
  6015. In order to create executable programs and images, the build-side
  6016. procedures @code{build-program} and @code{build-image} can be used.
  6017. They should be called in a build phase after the
  6018. @code{create-asdf-configuration} phase, so that the system which was
  6019. just built can be used within the resulting image. @code{build-program}
  6020. requires a list of Common Lisp expressions to be passed as the
  6021. @code{#:entry-program} argument.
  6022. By default, all the @file{.asd} files present in the sources are read to
  6023. find system definitions. The @code{#:asd-files} parameter can be used
  6024. to specify the list of @file{.asd} files to read. Furthermore, if the
  6025. package defines a system for its tests in a separate file, it will be
  6026. loaded before the tests are run if it is specified by the
  6027. @code{#:test-asd-file} parameter. If it is not set, the files
  6028. @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
  6029. and @code{test.asd} will be tried if they exist.
  6030. If for some reason the package must be named in a different way than the
  6031. naming conventions suggest, or if several systems must be compiled, the
  6032. @code{#:asd-systems} parameter can be used to specify the list of system
  6033. names.
  6034. @end defvr
  6035. @defvr {Scheme Variable} cargo-build-system
  6036. @cindex Rust programming language
  6037. @cindex Cargo (Rust build system)
  6038. This variable is exported by @code{(guix build-system cargo)}. It
  6039. supports builds of packages using Cargo, the build tool of the
  6040. @uref{https://www.rust-lang.org, Rust programming language}.
  6041. It adds @code{rustc} and @code{cargo} to the set of inputs.
  6042. A different Rust package can be specified with the @code{#:rust} parameter.
  6043. Regular cargo dependencies should be added to the package definition similarly
  6044. to other packages; those needed only at build time to native-inputs, others to
  6045. inputs. If you need to add source-only crates then you should add them to via
  6046. the @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
  6047. spec can be a package or a source definition. Note that the spec must
  6048. evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
  6049. file at its root, or it will be ignored. Similarly, cargo dev-dependencies
  6050. should be added to the package definition via the
  6051. @code{#:cargo-development-inputs} parameter.
  6052. In its @code{configure} phase, this build system will make any source inputs
  6053. specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
  6054. parameters available to cargo. It will also remove an included
  6055. @code{Cargo.lock} file to be recreated by @code{cargo} during the
  6056. @code{build} phase. The @code{package} phase will run @code{cargo package}
  6057. to create a source crate for future use. The @code{install} phase installs
  6058. the binaries defined by the crate. Unless @code{install-source? #f} is
  6059. defined it will also install a source crate repository of itself and unpacked
  6060. sources, to ease in future hacking on rust packages.
  6061. @end defvr
  6062. @defvr {Scheme Variable} chicken-build-system
  6063. This variable is exported by @code{(guix build-system chicken)}. It
  6064. builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
  6065. ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
  6066. gets compiled by a C compiler, in this case GCC.
  6067. This build system adds @code{chicken} to the package inputs, as well as
  6068. the packages of @code{gnu-build-system}.
  6069. The build system can't (yet) deduce the egg's name automatically, so just like
  6070. with @code{go-build-system} and its @code{#:import-path}, you should define
  6071. @code{#:egg-name} in the package's @code{arguments} field.
  6072. For example, if you are packaging the @code{srfi-1} egg:
  6073. @lisp
  6074. (arguments '(#:egg-name "srfi-1"))
  6075. @end lisp
  6076. Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
  6077. because CHICKEN doesn't embed absolute references in compiled eggs.
  6078. Test dependencies should go to @code{native-inputs}, as usual.
  6079. @end defvr
  6080. @defvr {Scheme Variable} copy-build-system
  6081. This variable is exported by @code{(guix build-system copy)}. It
  6082. supports builds of simple packages that don't require much compiling,
  6083. mostly just moving files around.
  6084. It adds much of the @code{gnu-build-system} packages to the set of
  6085. inputs. Because of this, the @code{copy-build-system} does not require
  6086. all the boilerplate code often needed for the
  6087. @code{trivial-build-system}.
  6088. To further simplify the file installation process, an
  6089. @code{#:install-plan} argument is exposed to let the packager specify
  6090. which files go where. The install plan is a list of @code{(@var{source}
  6091. @var{target} [@var{filters}])}. @var{filters} are optional.
  6092. @itemize
  6093. @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
  6094. @itemize
  6095. @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
  6096. @item Otherwise install @var{source} as @var{target}.
  6097. @end itemize
  6098. @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
  6099. the trailing slash of @var{target} is implied with the same meaning
  6100. as above.
  6101. @itemize
  6102. @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
  6103. @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
  6104. @code{#:exclude-regexp}, only select files are installed depending on
  6105. the filters. Each filters is specified by a list of strings.
  6106. @itemize
  6107. @item With @code{#:include}, install all the files which the path suffix matches
  6108. at least one of the elements in the given list.
  6109. @item With @code{#:include-regexp}, install all the files which the
  6110. subpaths match at least one of the regular expressions in the given
  6111. list.
  6112. @item The @code{#:exclude} and @code{#:exclude-regexp} filters
  6113. are the complement of their inclusion counterpart. Without @code{#:include} flags,
  6114. install all files but those matching the exclusion filters.
  6115. If both inclusions and exclusions are specified, the exclusions are done
  6116. on top of the inclusions.
  6117. @end itemize
  6118. @end itemize
  6119. In all cases, the paths relative to @var{source} are preserved within
  6120. @var{target}.
  6121. @end itemize
  6122. Examples:
  6123. @itemize
  6124. @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
  6125. @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
  6126. @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
  6127. e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
  6128. @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
  6129. @file{share/my-app/sub/file}.
  6130. @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
  6131. @file{share/my-app/file}.
  6132. @end itemize
  6133. @end defvr
  6134. @cindex Clojure (programming language)
  6135. @cindex simple Clojure build system
  6136. @defvr {Scheme Variable} clojure-build-system
  6137. This variable is exported by @code{(guix build-system clojure)}. It implements
  6138. a simple build procedure for @uref{https://clojure.org/, Clojure} packages
  6139. using plain old @code{compile} in Clojure. Cross-compilation is not supported
  6140. yet.
  6141. It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
  6142. Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
  6143. @code{#:zip} parameters, respectively.
  6144. A list of source directories, test directories and jar names can be specified
  6145. with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
  6146. parameters, respectively. Compile directory and main class can be specified
  6147. with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
  6148. Other parameters are documented below.
  6149. This build system is an extension of @code{ant-build-system}, but with the
  6150. following phases changed:
  6151. @table @code
  6152. @item build
  6153. This phase calls @code{compile} in Clojure to compile source files and runs
  6154. @command{jar} to create jars from both source files and compiled files
  6155. according to the include list and exclude list specified in
  6156. @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
  6157. has priority over the include list. These lists consist of symbols
  6158. representing Clojure libraries or the special keyword @code{#:all} representing
  6159. all Clojure libraries found under the source directories. The parameter
  6160. @code{#:omit-source?} decides if source should be included into the jars.
  6161. @item check
  6162. This phase runs tests according to the include list and exclude list specified
  6163. in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
  6164. meanings are analogous to that of @code{#:aot-include} and
  6165. @code{#:aot-exclude}, except that the special keyword @code{#:all} now
  6166. stands for all Clojure libraries found under the test directories. The
  6167. parameter @code{#:tests?} decides if tests should be run.
  6168. @item install
  6169. This phase installs all jars built previously.
  6170. @end table
  6171. Apart from the above, this build system also contains an additional phase:
  6172. @table @code
  6173. @item install-doc
  6174. This phase installs all top-level files with base name matching
  6175. @code{%doc-regex}. A different regex can be specified with the
  6176. @code{#:doc-regex} parameter. All files (recursively) inside the documentation
  6177. directories specified in @code{#:doc-dirs} are installed as well.
  6178. @end table
  6179. @end defvr
  6180. @defvr {Scheme Variable} cmake-build-system
  6181. This variable is exported by @code{(guix build-system cmake)}. It
  6182. implements the build procedure for packages using the
  6183. @url{https://www.cmake.org, CMake build tool}.
  6184. It automatically adds the @code{cmake} package to the set of inputs.
  6185. Which package is used can be specified with the @code{#:cmake}
  6186. parameter.
  6187. The @code{#:configure-flags} parameter is taken as a list of flags
  6188. passed to the @command{cmake} command. The @code{#:build-type}
  6189. parameter specifies in abstract terms the flags passed to the compiler;
  6190. it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
  6191. debugging information''), which roughly means that code is compiled with
  6192. @code{-O2 -g}, as is the case for Autoconf-based packages by default.
  6193. @end defvr
  6194. @defvr {Scheme Variable} dune-build-system
  6195. This variable is exported by @code{(guix build-system dune)}. It
  6196. supports builds of packages using @uref{https://dune.build/, Dune}, a build
  6197. tool for the OCaml programming language. It is implemented as an extension
  6198. of the @code{ocaml-build-system} which is described below. As such, the
  6199. @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
  6200. system.
  6201. It automatically adds the @code{dune} package to the set of inputs.
  6202. Which package is used can be specified with the @code{#:dune}
  6203. parameter.
  6204. There is no @code{configure} phase because dune packages typically don't
  6205. need to be configured. The @code{#:build-flags} parameter is taken as a
  6206. list of flags passed to the @code{dune} command during the build.
  6207. The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
  6208. command instead of the more recent @code{dune} command while building
  6209. a package. Its default value is @code{#f}.
  6210. The @code{#:package} parameter can be passed to specify a package name, which
  6211. is useful when a package contains multiple packages and you want to build
  6212. only one of them. This is equivalent to passing the @code{-p} argument to
  6213. @code{dune}.
  6214. @end defvr
  6215. @defvr {Scheme Variable} go-build-system
  6216. This variable is exported by @code{(guix build-system go)}. It
  6217. implements a build procedure for Go packages using the standard
  6218. @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
  6219. Go build mechanisms}.
  6220. The user is expected to provide a value for the key @code{#:import-path}
  6221. and, in some cases, @code{#:unpack-path}. The
  6222. @url{https://golang.org/doc/code.html#ImportPaths, import path}
  6223. corresponds to the file system path expected by the package's build
  6224. scripts and any referring packages, and provides a unique way to
  6225. refer to a Go package. It is typically based on a combination of the
  6226. package source code's remote URI and file system hierarchy structure. In
  6227. some cases, you will need to unpack the package's source code to a
  6228. different directory structure than the one indicated by the import path,
  6229. and @code{#:unpack-path} should be used in such cases.
  6230. Packages that provide Go libraries should install their source code into
  6231. the built output. The key @code{#:install-source?}, which defaults to
  6232. @code{#t}, controls whether or not the source code is installed. It can
  6233. be set to @code{#f} for packages that only provide executable files.
  6234. @end defvr
  6235. @defvr {Scheme Variable} glib-or-gtk-build-system
  6236. This variable is exported by @code{(guix build-system glib-or-gtk)}. It
  6237. is intended for use with packages making use of GLib or GTK+.
  6238. This build system adds the following two phases to the ones defined by
  6239. @code{gnu-build-system}:
  6240. @table @code
  6241. @item glib-or-gtk-wrap
  6242. The phase @code{glib-or-gtk-wrap} ensures that programs in
  6243. @file{bin/} are able to find GLib ``schemas'' and
  6244. @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
  6245. modules}. This is achieved by wrapping the programs in launch scripts
  6246. that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
  6247. environment variables.
  6248. It is possible to exclude specific package outputs from that wrapping
  6249. process by listing their names in the
  6250. @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
  6251. when an output is known not to contain any GLib or GTK+ binaries, and
  6252. where wrapping would gratuitously add a dependency of that output on
  6253. GLib and GTK+.
  6254. @item glib-or-gtk-compile-schemas
  6255. The phase @code{glib-or-gtk-compile-schemas} makes sure that all
  6256. @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
  6257. GSettings schemas} of GLib are compiled. Compilation is performed by the
  6258. @command{glib-compile-schemas} program. It is provided by the package
  6259. @code{glib:bin} which is automatically imported by the build system.
  6260. The @code{glib} package providing @command{glib-compile-schemas} can be
  6261. specified with the @code{#:glib} parameter.
  6262. @end table
  6263. Both phases are executed after the @code{install} phase.
  6264. @end defvr
  6265. @defvr {Scheme Variable} guile-build-system
  6266. This build system is for Guile packages that consist exclusively of Scheme
  6267. code and that are so lean that they don't even have a makefile, let alone a
  6268. @file{configure} script. It compiles Scheme code using @command{guild
  6269. compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
  6270. installs the @file{.scm} and @file{.go} files in the right place. It also
  6271. installs documentation.
  6272. This build system supports cross-compilation by using the
  6273. @option{--target} option of @samp{guild compile}.
  6274. Packages built with @code{guile-build-system} must provide a Guile package in
  6275. their @code{native-inputs} field.
  6276. @end defvr
  6277. @defvr {Scheme Variable} julia-build-system
  6278. This variable is exported by @code{(guix build-system julia)}. It
  6279. implements the build procedure used by @uref{https://julialang.org/,
  6280. julia} packages, which essentially is similar to running @samp{julia -e
  6281. 'using Pkg; Pkg.add(package)'} in an environment where
  6282. @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
  6283. Tests are run by calling @code{/test/runtests.jl}.
  6284. The Julia package name is read from the file @file{Project.toml}. This
  6285. value can be overridden by passing the argument @code{#:julia-package-name}
  6286. (which must be correctly capitalized).
  6287. Julia packages usually manage they binary dependencies via
  6288. @code{JLLWrappers.jl}, a Julia package that creates a module (named
  6289. after the wrapped library followed by @code{_jll.jl}.
  6290. To add the binary path @code{_jll.jl} packages, you need to patch the
  6291. files under @file{src/wrappers/}, replacing the call to the macro
  6292. @code{JLLWrappers.@@generate_wrapper_header}, adding as a secound
  6293. argument containing the store path the binary.
  6294. As an example, in the MbedTLS Julia package, we add a build phase
  6295. (@pxref{Build Phases}) to insert the absolute file name of the wrapped
  6296. MbedTLS package:
  6297. @lisp
  6298. (add-after 'unpack 'override-binary-path
  6299. (lambda* (#:key inputs #:allow-other-keys)
  6300. (for-each (lambda (wrapper)
  6301. (substitute* wrapper
  6302. (("generate_wrapper_header.*")
  6303. (string-append
  6304. "generate_wrapper_header(\"MbedTLS\", \""
  6305. (assoc-ref inputs "mbedtls-apache") "\")\n"))))
  6306. ;; There's a Julia file for each platform, override them all.
  6307. (find-files "src/wrappers/" "\\.jl$"))))
  6308. @end lisp
  6309. Some older packages that aren't using @file{Package.toml} yet, will require
  6310. this file to be created, too. The function @code{julia-create-package-toml}
  6311. helps creating the file. You need to pass the outputs and the source of the
  6312. package, it's name (the same as the @code{file-name} parameter), the package
  6313. uuid, the package version, and a list of dependencies specified by their name
  6314. and their uuid.
  6315. @end defvr
  6316. @defvr {Scheme Variable} maven-build-system
  6317. This variable is exported by @code{(guix build-system maven)}. It implements
  6318. a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
  6319. is a dependency and lifecycle management tool for Java. A user of Maven
  6320. specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
  6321. When Maven does not have one of the dependencies or plugins in its repository,
  6322. it will download them and use them to build the package.
  6323. The maven build system ensures that maven will not try to download any
  6324. dependency by running in offline mode. Maven will fail if a dependency is
  6325. missing. Before running Maven, the @file{pom.xml} (and subprojects) are
  6326. modified to specify the version of dependencies and plugins that match the
  6327. versions available in the guix build environment. Dependencies and plugins
  6328. must be installed in the fake maven repository at @file{lib/m2}, and are
  6329. symlinked into a proper repository before maven is run. Maven is instructed
  6330. to use that repository for the build and installs built artifacts there.
  6331. Changed files are copied to the @file{lib/m2} directory of the package output.
  6332. You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
  6333. or let the build system use the default @file{pom.xml} file in the sources.
  6334. In case you need to specify a dependency's version manually, you can use the
  6335. @code{#:local-packages} argument. It takes an association list where the key
  6336. is the groupId of the package and its value is an association list where the
  6337. key is the artifactId of the package and its value is the version you want to
  6338. override in the @file{pom.xml}.
  6339. Some packages use dependencies or plugins that are not useful at runtime nor
  6340. at build time in Guix. You can alter the @file{pom.xml} file to remove them
  6341. using the @code{#:exclude} argument. Its value is an association list where
  6342. the key is the groupId of the plugin or dependency you want to remove, and
  6343. the value is a list of artifactId you want to remove.
  6344. You can override the default @code{jdk} and @code{maven} packages with the
  6345. corresponding argument, @code{#:jdk} and @code{#:maven}.
  6346. The @code{#:maven-plugins} argument is a list of maven plugins used during
  6347. the build, with the same format as the @code{inputs} fields of the package
  6348. declaration. Its default value is @code{(default-maven-plugins)} which is
  6349. also exported.
  6350. @end defvr
  6351. @defvr {Scheme Variable} minify-build-system
  6352. This variable is exported by @code{(guix build-system minify)}. It
  6353. implements a minification procedure for simple JavaScript packages.
  6354. It adds @code{uglify-js} to the set of inputs and uses it to compress
  6355. all JavaScript files in the @file{src} directory. A different minifier
  6356. package can be specified with the @code{#:uglify-js} parameter, but it
  6357. is expected that the package writes the minified code to the standard
  6358. output.
  6359. When the input JavaScript files are not all located in the @file{src}
  6360. directory, the parameter @code{#:javascript-files} can be used to
  6361. specify a list of file names to feed to the minifier.
  6362. @end defvr
  6363. @defvr {Scheme Variable} ocaml-build-system
  6364. This variable is exported by @code{(guix build-system ocaml)}. It implements
  6365. a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
  6366. of choosing the correct set of commands to run for each package. OCaml
  6367. packages can expect many different commands to be run. This build system will
  6368. try some of them.
  6369. When the package has a @file{setup.ml} file present at the top-level, it will
  6370. run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
  6371. @code{ocaml setup.ml -install}. The build system will assume that this file
  6372. was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
  6373. care of setting the prefix and enabling tests if they are not disabled. You
  6374. can pass configure and build flags with the @code{#:configure-flags} and
  6375. @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
  6376. set of flags used to enable tests. The @code{#:use-make?} key can be used to
  6377. bypass this system in the build and install phases.
  6378. When the package has a @file{configure} file, it is assumed that it is a
  6379. hand-made configure script that requires a different argument format than
  6380. in the @code{gnu-build-system}. You can add more flags with the
  6381. @code{#:configure-flags} key.
  6382. When the package has a @file{Makefile} file (or @code{#:use-make?} is
  6383. @code{#t}), it will be used and more flags can be passed to the build and
  6384. install phases with the @code{#:make-flags} key.
  6385. Finally, some packages do not have these files and use a somewhat standard
  6386. location for its build system. In that case, the build system will run
  6387. @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
  6388. providing the path to the required findlib module. Additional flags can
  6389. be passed via the @code{#:build-flags} key. Install is taken care of by
  6390. @command{opam-installer}. In this case, the @code{opam} package must
  6391. be added to the @code{native-inputs} field of the package definition.
  6392. Note that most OCaml packages assume they will be installed in the same
  6393. directory as OCaml, which is not what we want in guix. In particular, they
  6394. will install @file{.so} files in their module's directory, which is usually
  6395. fine because it is in the OCaml compiler directory. In guix though, these
  6396. libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
  6397. variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
  6398. @file{.so} libraries should be installed.
  6399. @end defvr
  6400. @defvr {Scheme Variable} python-build-system
  6401. This variable is exported by @code{(guix build-system python)}. It
  6402. implements the more or less standard build procedure used by Python
  6403. packages, which consists in running @code{python setup.py build} and
  6404. then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
  6405. For packages that install stand-alone Python programs under @code{bin/},
  6406. it takes care of wrapping these programs so that their @env{PYTHONPATH}
  6407. environment variable points to all the Python libraries they depend on.
  6408. Which Python package is used to perform the build can be specified with
  6409. the @code{#:python} parameter. This is a useful way to force a package
  6410. to be built for a specific version of the Python interpreter, which
  6411. might be necessary if the package is only compatible with a single
  6412. interpreter version.
  6413. By default guix calls @code{setup.py} under control of
  6414. @code{setuptools}, much like @command{pip} does. Some packages are not
  6415. compatible with setuptools (and pip), thus you can disable this by
  6416. setting the @code{#:use-setuptools?} parameter to @code{#f}.
  6417. @end defvr
  6418. @defvr {Scheme Variable} perl-build-system
  6419. This variable is exported by @code{(guix build-system perl)}. It
  6420. implements the standard build procedure for Perl packages, which either
  6421. consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
  6422. followed by @code{Build} and @code{Build install}; or in running
  6423. @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
  6424. @code{make} and @code{make install}, depending on which of
  6425. @code{Build.PL} or @code{Makefile.PL} is present in the package
  6426. distribution. Preference is given to the former if both @code{Build.PL}
  6427. and @code{Makefile.PL} exist in the package distribution. This
  6428. preference can be reversed by specifying @code{#t} for the
  6429. @code{#:make-maker?} parameter.
  6430. The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
  6431. passes flags specified by the @code{#:make-maker-flags} or
  6432. @code{#:module-build-flags} parameter, respectively.
  6433. Which Perl package is used can be specified with @code{#:perl}.
  6434. @end defvr
  6435. @defvr {Scheme Variable} renpy-build-system
  6436. This variable is exported by @code{(guix build-system renpy)}. It implements
  6437. the more or less standard build procedure used by Ren'py games, which consists
  6438. of loading @code{#:game} once, thereby creating bytecode for it.
  6439. It further creates a wrapper script in @code{bin/} and a desktop entry in
  6440. @code{share/applications}, both of which can be used to launch the game.
  6441. Which Ren'py package is used can be specified with @code{#:renpy}.
  6442. Games can also be installed in outputs other than ``out'' by using
  6443. @code{#:output}.
  6444. @end defvr
  6445. @defvr {Scheme Variable} qt-build-system
  6446. This variable is exported by @code{(guix build-system qt)}. It
  6447. is intended for use with applications using Qt or KDE.
  6448. This build system adds the following two phases to the ones defined by
  6449. @code{cmake-build-system}:
  6450. @table @code
  6451. @item check-setup
  6452. The phase @code{check-setup} prepares the environment for running
  6453. the checks as commonly used by Qt test programs.
  6454. For now this only sets some environment variables:
  6455. @code{QT_QPA_PLATFORM=offscreen},
  6456. @code{DBUS_FATAL_WARNINGS=0} and
  6457. @code{CTEST_OUTPUT_ON_FAILURE=1}.
  6458. This phase is added before the @code{check} phase.
  6459. It's a separate phase to ease adjusting if necessary.
  6460. @item qt-wrap
  6461. The phase @code{qt-wrap}
  6462. searches for Qt5 plugin paths, QML paths and some XDG in the inputs
  6463. and output. In case some path is found, all programs in the output's
  6464. @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
  6465. are wrapped in scripts defining the necessary environment variables.
  6466. It is possible to exclude specific package outputs from that wrapping process
  6467. by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
  6468. This is useful when an output is known not to contain any Qt binaries, and
  6469. where wrapping would gratuitously add a dependency of that output on Qt, KDE,
  6470. or such.
  6471. This phase is added after the @code{install} phase.
  6472. @end table
  6473. @end defvr
  6474. @defvr {Scheme Variable} r-build-system
  6475. This variable is exported by @code{(guix build-system r)}. It
  6476. implements the build procedure used by @uref{https://r-project.org, R}
  6477. packages, which essentially is little more than running @samp{R CMD
  6478. INSTALL --library=/gnu/store/@dots{}} in an environment where
  6479. @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
  6480. run after installation using the R function
  6481. @code{tools::testInstalledPackage}.
  6482. @end defvr
  6483. @defvr {Scheme Variable} rakudo-build-system
  6484. This variable is exported by @code{(guix build-system rakudo)}. It
  6485. implements the build procedure used by @uref{https://rakudo.org/,
  6486. Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
  6487. package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
  6488. installs the binaries, library files and the resources, as well as wrap
  6489. the files under the @code{bin/} directory. Tests can be skipped by
  6490. passing @code{#f} to the @code{tests?} parameter.
  6491. Which rakudo package is used can be specified with @code{rakudo}.
  6492. Which perl6-tap-harness package used for the tests can be specified with
  6493. @code{#:prove6} or removed by passing @code{#f} to the
  6494. @code{with-prove6?} parameter.
  6495. Which perl6-zef package used for tests and installing can be specified
  6496. with @code{#:zef} or removed by passing @code{#f} to the
  6497. @code{with-zef?} parameter.
  6498. @end defvr
  6499. @defvr {Scheme Variable} texlive-build-system
  6500. This variable is exported by @code{(guix build-system texlive)}. It is
  6501. used to build TeX packages in batch mode with a specified engine. The
  6502. build system sets the @env{TEXINPUTS} variable to find all TeX source
  6503. files in the inputs.
  6504. By default it runs @code{luatex} on all files ending on @code{ins}. A
  6505. different engine and format can be specified with the
  6506. @code{#:tex-format} argument. Different build targets can be specified
  6507. with the @code{#:build-targets} argument, which expects a list of file
  6508. names. The build system adds only @code{texlive-bin} and
  6509. @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
  6510. inputs. Both can be overridden with the arguments @code{#:texlive-bin}
  6511. and @code{#:texlive-latex-base}, respectively.
  6512. The @code{#:tex-directory} parameter tells the build system where to
  6513. install the built files under the texmf tree.
  6514. @end defvr
  6515. @defvr {Scheme Variable} ruby-build-system
  6516. This variable is exported by @code{(guix build-system ruby)}. It
  6517. implements the RubyGems build procedure used by Ruby packages, which
  6518. involves running @code{gem build} followed by @code{gem install}.
  6519. The @code{source} field of a package that uses this build system
  6520. typically references a gem archive, since this is the format that Ruby
  6521. developers use when releasing their software. The build system unpacks
  6522. the gem archive, potentially patches the source, runs the test suite,
  6523. repackages the gem, and installs it. Additionally, directories and
  6524. tarballs may be referenced to allow building unreleased gems from Git or
  6525. a traditional source release tarball.
  6526. Which Ruby package is used can be specified with the @code{#:ruby}
  6527. parameter. A list of additional flags to be passed to the @command{gem}
  6528. command can be specified with the @code{#:gem-flags} parameter.
  6529. @end defvr
  6530. @defvr {Scheme Variable} waf-build-system
  6531. This variable is exported by @code{(guix build-system waf)}. It
  6532. implements a build procedure around the @code{waf} script. The common
  6533. phases---@code{configure}, @code{build}, and @code{install}---are
  6534. implemented by passing their names as arguments to the @code{waf}
  6535. script.
  6536. The @code{waf} script is executed by the Python interpreter. Which
  6537. Python package is used to run the script can be specified with the
  6538. @code{#:python} parameter.
  6539. @end defvr
  6540. @defvr {Scheme Variable} scons-build-system
  6541. This variable is exported by @code{(guix build-system scons)}. It
  6542. implements the build procedure used by the SCons software construction
  6543. tool. This build system runs @code{scons} to build the package,
  6544. @code{scons test} to run tests, and then @code{scons install} to install
  6545. the package.
  6546. Additional flags to be passed to @code{scons} can be specified with the
  6547. @code{#:scons-flags} parameter. The default build and install targets
  6548. can be overridden with @code{#:build-targets} and
  6549. @code{#:install-targets} respectively. The version of Python used to
  6550. run SCons can be specified by selecting the appropriate SCons package
  6551. with the @code{#:scons} parameter.
  6552. @end defvr
  6553. @defvr {Scheme Variable} haskell-build-system
  6554. This variable is exported by @code{(guix build-system haskell)}. It
  6555. implements the Cabal build procedure used by Haskell packages, which
  6556. involves running @code{runhaskell Setup.hs configure
  6557. --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
  6558. Instead of installing the package by running @code{runhaskell Setup.hs
  6559. install}, to avoid trying to register libraries in the read-only
  6560. compiler store directory, the build system uses @code{runhaskell
  6561. Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
  6562. addition, the build system generates the package documentation by
  6563. running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
  6564. is passed. Optional Haddock parameters can be passed with the help of
  6565. the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
  6566. not found, the build system looks for @code{Setup.lhs} instead.
  6567. Which Haskell compiler is used can be specified with the @code{#:haskell}
  6568. parameter which defaults to @code{ghc}.
  6569. @end defvr
  6570. @defvr {Scheme Variable} dub-build-system
  6571. This variable is exported by @code{(guix build-system dub)}. It
  6572. implements the Dub build procedure used by D packages, which
  6573. involves running @code{dub build} and @code{dub run}.
  6574. Installation is done by copying the files manually.
  6575. Which D compiler is used can be specified with the @code{#:ldc}
  6576. parameter which defaults to @code{ldc}.
  6577. @end defvr
  6578. @anchor{emacs-build-system}
  6579. @defvr {Scheme Variable} emacs-build-system
  6580. This variable is exported by @code{(guix build-system emacs)}. It
  6581. implements an installation procedure similar to the packaging system
  6582. of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
  6583. It first creates the @code{@code{package}-autoloads.el} file, then it
  6584. byte compiles all Emacs Lisp files. Differently from the Emacs
  6585. packaging system, the Info documentation files are moved to the standard
  6586. documentation directory and the @file{dir} file is deleted. The Elisp
  6587. package files are installed directly under @file{share/emacs/site-lisp}.
  6588. @end defvr
  6589. @defvr {Scheme Variable} font-build-system
  6590. This variable is exported by @code{(guix build-system font)}. It
  6591. implements an installation procedure for font packages where upstream
  6592. provides pre-compiled TrueType, OpenType, etc.@: font files that merely
  6593. need to be copied into place. It copies font files to standard
  6594. locations in the output directory.
  6595. @end defvr
  6596. @defvr {Scheme Variable} meson-build-system
  6597. This variable is exported by @code{(guix build-system meson)}. It
  6598. implements the build procedure for packages that use
  6599. @url{https://mesonbuild.com, Meson} as their build system.
  6600. It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
  6601. of inputs, and they can be changed with the parameters @code{#:meson}
  6602. and @code{#:ninja} if needed. The default Meson is
  6603. @code{meson-for-build}, which is special because it doesn't clear the
  6604. @code{RUNPATH} of binaries and libraries when they are installed.
  6605. This build system is an extension of @code{gnu-build-system}, but with the
  6606. following phases changed to some specific for Meson:
  6607. @table @code
  6608. @item configure
  6609. The phase runs @code{meson} with the flags specified in
  6610. @code{#:configure-flags}. The flag @option{--buildtype} is always set to
  6611. @code{debugoptimized} unless something else is specified in
  6612. @code{#:build-type}.
  6613. @item build
  6614. The phase runs @code{ninja} to build the package in parallel by default, but
  6615. this can be changed with @code{#:parallel-build?}.
  6616. @item check
  6617. The phase runs @code{ninja} with the target specified in @code{#:test-target},
  6618. which is @code{"test"} by default.
  6619. @item install
  6620. The phase runs @code{ninja install} and can not be changed.
  6621. @end table
  6622. Apart from that, the build system also adds the following phases:
  6623. @table @code
  6624. @item fix-runpath
  6625. This phase ensures that all binaries can find the libraries they need.
  6626. It searches for required libraries in subdirectories of the package being
  6627. built, and adds those to @code{RUNPATH} where needed. It also removes
  6628. references to libraries left over from the build phase by
  6629. @code{meson-for-build}, such as test dependencies, that aren't actually
  6630. required for the program to run.
  6631. @item glib-or-gtk-wrap
  6632. This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
  6633. is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
  6634. @item glib-or-gtk-compile-schemas
  6635. This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
  6636. is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
  6637. @end table
  6638. @end defvr
  6639. @defvr {Scheme Variable} linux-module-build-system
  6640. @code{linux-module-build-system} allows building Linux kernel modules.
  6641. @cindex build phases
  6642. This build system is an extension of @code{gnu-build-system}, but with the
  6643. following phases changed:
  6644. @table @code
  6645. @item configure
  6646. This phase configures the environment so that the Linux kernel's Makefile
  6647. can be used to build the external kernel module.
  6648. @item build
  6649. This phase uses the Linux kernel's Makefile in order to build the external
  6650. kernel module.
  6651. @item install
  6652. This phase uses the Linux kernel's Makefile in order to install the external
  6653. kernel module.
  6654. @end table
  6655. It is possible and useful to specify the Linux kernel to use for building
  6656. the module (in the @code{arguments} form of a package using the
  6657. @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
  6658. @end defvr
  6659. @defvr {Scheme Variable} node-build-system
  6660. This variable is exported by @code{(guix build-system node)}. It
  6661. implements the build procedure used by @uref{https://nodejs.org,
  6662. Node.js}, which implements an approximation of the @code{npm install}
  6663. command, followed by an @code{npm test} command.
  6664. Which Node.js package is used to interpret the @code{npm} commands can
  6665. be specified with the @code{#:node} parameter which defaults to
  6666. @code{node}.
  6667. @end defvr
  6668. Lastly, for packages that do not need anything as sophisticated, a
  6669. ``trivial'' build system is provided. It is trivial in the sense that
  6670. it provides basically no support: it does not pull any implicit inputs,
  6671. and does not have a notion of build phases.
  6672. @defvr {Scheme Variable} trivial-build-system
  6673. This variable is exported by @code{(guix build-system trivial)}.
  6674. This build system requires a @code{#:builder} argument. This argument
  6675. must be a Scheme expression that builds the package output(s)---as
  6676. with @code{build-expression->derivation} (@pxref{Derivations,
  6677. @code{build-expression->derivation}}).
  6678. @end defvr
  6679. @node Build Phases
  6680. @section Build Phases
  6681. @cindex build phases, for packages
  6682. Almost all package build systems implement a notion @dfn{build phases}:
  6683. a sequence of actions that the build system executes, when you build the
  6684. package, leading to the installed byproducts in the store. A notable
  6685. exception is the ``bare-bones'' @code{trivial-build-system}
  6686. (@pxref{Build Systems}).
  6687. As discussed in the previous section, those build systems provide a
  6688. standard list of phases. For @code{gnu-build-system}, the standard
  6689. phases include an @code{unpack} phase to unpack the source code tarball,
  6690. a @command{configure} phase to run @code{./configure}, a @code{build}
  6691. phase to run @command{make}, and (among others) an @code{install} phase
  6692. to run @command{make install}; @pxref{Build Systems}, for a more
  6693. detailed view of these phases. Likewise, @code{cmake-build-system}
  6694. inherits these phases, but its @code{configure} phase runs
  6695. @command{cmake} instead of @command{./configure}. Other build systems,
  6696. such as @code{python-build-system}, have a wholly different list of
  6697. standard phases. All this code runs on the @dfn{build side}: it is
  6698. evaluated when you actually build the package, in a dedicated build
  6699. process spawned by the build daemon (@pxref{Invoking guix-daemon}).
  6700. Build phases are represented as association lists or ``alists''
  6701. (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
  6702. each key is a symbol for the name of the phase and the associated value
  6703. is a procedure that accepts an arbitrary number of arguments. By
  6704. convention, those procedures receive information about the build in the
  6705. form of @dfn{keyword parameters}, which they can use or ignore.
  6706. For example, here is how @code{(guix build gnu-build-system)} defines
  6707. @code{%standard-phases}, the variable holding its alist of build
  6708. phases@footnote{We present a simplified view of those build phases, but
  6709. do take a look at @code{(guix build gnu-build-system)} to see all the
  6710. details!}:
  6711. @lisp
  6712. ;; The build phases of 'gnu-build-system'.
  6713. (define* (unpack #:key source #:allow-other-keys)
  6714. ;; Extract the source tarball.
  6715. (invoke "tar" "xvf" source))
  6716. (define* (configure #:key outputs #:allow-other-keys)
  6717. ;; Run the 'configure' script. Install to output "out".
  6718. (let ((out (assoc-ref outputs "out")))
  6719. (invoke "./configure"
  6720. (string-append "--prefix=" out))))
  6721. (define* (build #:allow-other-keys)
  6722. ;; Compile.
  6723. (invoke "make"))
  6724. (define* (check #:key (test-target "check") (tests? #true)
  6725. #:allow-other-keys)
  6726. ;; Run the test suite.
  6727. (if tests?
  6728. (invoke "make" test-target)
  6729. (display "test suite not run\n")))
  6730. (define* (install #:allow-other-keys)
  6731. ;; Install files to the prefix 'configure' specified.
  6732. (invoke "make" "install"))
  6733. (define %standard-phases
  6734. ;; The list of standard phases (quite a few are omitted
  6735. ;; for brevity). Each element is a symbol/procedure pair.
  6736. (list (cons 'unpack unpack)
  6737. (cons 'configure configure)
  6738. (cons 'build build)
  6739. (cons 'check check)
  6740. (cons 'install install)))
  6741. @end lisp
  6742. This shows how @code{%standard-phases} is defined as a list of
  6743. symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
  6744. Manual}). The first pair associates the @code{unpack} procedure with
  6745. the @code{unpack} symbol---a name; the second pair defines the
  6746. @code{configure} phase similarly, and so on. When building a package
  6747. that uses @code{gnu-build-system} with its default list of phases, those
  6748. phases are executed sequentially. You can see the name of each phase
  6749. started and completed in the build log of packages that you build.
  6750. Let's now look at the procedures themselves. Each one is defined with
  6751. @code{define*}: @code{#:key} lists keyword parameters the procedure
  6752. accepts, possibly with a default value, and @code{#:allow-other-keys}
  6753. specifies that other keyword parameters are ignored (@pxref{Optional
  6754. Arguments,,, guile, GNU Guile Reference Manual}).
  6755. The @code{unpack} procedure honors the @code{source} parameter, which
  6756. the build system uses to pass the file name of the source tarball (or
  6757. version control checkout), and it ignores other parameters. The
  6758. @code{configure} phase only cares about the @code{outputs} parameter, an
  6759. alist mapping package output names to their store file name
  6760. (@pxref{Packages with Multiple Outputs}). It extracts the file name of
  6761. for @code{out}, the default output, and passes it to
  6762. @command{./configure} as the installation prefix, meaning that
  6763. @command{make install} will eventually copy all the files in that
  6764. directory (@pxref{Configuration, configuration and makefile
  6765. conventions,, standards, GNU Coding Standards}). @code{build} and
  6766. @code{install} ignore all their arguments. @code{check} honors the
  6767. @code{test-target} argument, which specifies the name of the Makefile
  6768. target to run tests; it prints a message and skips tests when
  6769. @code{tests?} is false.
  6770. @cindex build phases, customizing
  6771. The list of phases used for a particular package can be changed with the
  6772. @code{#:phases} parameter of the build system. Changing the set of
  6773. build phases boils down to building a new alist of phases based on the
  6774. @code{%standard-phases} alist described above. This can be done with
  6775. standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
  6776. Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
  6777. more convenient to do so with @code{modify-phases} (@pxref{Build
  6778. Utilities, @code{modify-phases}}).
  6779. Here is an example of a package definition that removes the
  6780. @code{configure} phase of @code{%standard-phases} and inserts a new
  6781. phase before the @code{build} phase, called
  6782. @code{set-prefix-in-makefile}:
  6783. @lisp
  6784. (define-public example
  6785. (package
  6786. (name "example")
  6787. ;; other fields omitted
  6788. (build-system gnu-build-system)
  6789. (arguments
  6790. '(#:phases (modify-phases %standard-phases
  6791. (delete 'configure)
  6792. (add-before 'build 'set-prefix-in-makefile
  6793. (lambda* (#:key outputs #:allow-other-keys)
  6794. ;; Modify the makefile so that its
  6795. ;; 'PREFIX' variable points to "out".
  6796. (let ((out (assoc-ref outputs "out")))
  6797. (substitute* "Makefile"
  6798. (("PREFIX =.*")
  6799. (string-append "PREFIX = "
  6800. out "\n")))
  6801. #true))))))))
  6802. @end lisp
  6803. The new phase that is inserted is written as an anonymous procedure,
  6804. introduced with @code{lambda*}; it honors the @code{outputs} parameter
  6805. we have seen before. @xref{Build Utilities}, for more about the helpers
  6806. used by this phase, and for more examples of @code{modify-phases}.
  6807. @cindex code staging
  6808. @cindex staging, of code
  6809. Keep in mind that build phases are code evaluated at the time the
  6810. package is actually built. This explains why the whole
  6811. @code{modify-phases} expression above is quoted (it comes after the
  6812. @code{'} or apostrophe): it is @dfn{staged} for later execution.
  6813. @xref{G-Expressions}, for an explanation of code staging and the
  6814. @dfn{code strata} involved.
  6815. @node Build Utilities
  6816. @section Build Utilities
  6817. As soon as you start writing non-trivial package definitions
  6818. (@pxref{Defining Packages}) or other build actions
  6819. (@pxref{G-Expressions}), you will likely start looking for helpers for
  6820. ``shell-like'' actions---creating directories, copying and deleting
  6821. files recursively, manipulating build phases, and so on. The
  6822. @code{(guix build utils)} module provides such utility procedures.
  6823. Most build systems load @code{(guix build utils)} (@pxref{Build
  6824. Systems}). Thus, when writing custom build phases for your package
  6825. definitions, you can usually assume those procedures are in scope.
  6826. When writing G-expressions, you can import @code{(guix build utils)} on
  6827. the ``build side'' using @code{with-imported-modules} and then put it in
  6828. scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
  6829. guile, GNU Guile Reference Manual}):
  6830. @lisp
  6831. (with-imported-modules '((guix build utils)) ;import it
  6832. (computed-file "empty-tree"
  6833. #~(begin
  6834. ;; Put it in scope.
  6835. (use-modules (guix build utils))
  6836. ;; Happily use its 'mkdir-p' procedure.
  6837. (mkdir-p (string-append #$output "/a/b/c")))))
  6838. @end lisp
  6839. The remainder of this section is the reference for most of the utility
  6840. procedures provided by @code{(guix build utils)}.
  6841. @c TODO Document what's missing.
  6842. @subsection Dealing with Store File Names
  6843. This section documents procedures that deal with store file names.
  6844. @deffn {Scheme Procedure} %store-directory
  6845. Return the directory name of the store.
  6846. @end deffn
  6847. @deffn {Scheme Procedure} store-file-name? @var{file}
  6848. Return true if @var{file} is in the store.
  6849. @end deffn
  6850. @deffn {Scheme Procedure} strip-store-file-name @var{file}
  6851. Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
  6852. The result is typically a @code{"@var{package}-@var{version}"} string.
  6853. @end deffn
  6854. @deffn {Scheme Procedure} package-name->name+version @var{name}
  6855. Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
  6856. values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
  6857. unavailable, @var{name} and @code{#f} are returned. The first hyphen
  6858. followed by a digit is considered to introduce the version part.
  6859. @end deffn
  6860. @subsection File Types
  6861. The procedures below deal with files and file types.
  6862. @deffn {Scheme Procedure} directory-exists? @var{dir}
  6863. Return @code{#t} if @var{dir} exists and is a directory.
  6864. @end deffn
  6865. @deffn {Scheme Procedure} executable-file? @var{file}
  6866. Return @code{#t} if @var{file} exists and is executable.
  6867. @end deffn
  6868. @deffn {Scheme Procedure} symbolic-link? @var{file}
  6869. Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
  6870. @end deffn
  6871. @deffn {Scheme Procedure} elf-file? @var{file}
  6872. @deffnx {Scheme Procedure} ar-file? @var{file}
  6873. @deffnx {Scheme Procedure} gzip-file? @var{file}
  6874. Return @code{#t} if @var{file} is, respectively, an ELF file, an
  6875. @code{ar} archive (such as a @file{.a} static library), or a gzip file.
  6876. @end deffn
  6877. @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
  6878. If @var{file} is a gzip file, reset its embedded timestamp (as with
  6879. @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
  6880. When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
  6881. @end deffn
  6882. @subsection File Manipulation
  6883. The following procedures and macros help create, modify, and delete
  6884. files. They provide functionality comparable to common shell utilities
  6885. such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
  6886. @command{sed}. They complement Guile's extensive, but low-level, file
  6887. system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
  6888. @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
  6889. Run @var{body} with @var{directory} as the process's current directory.
  6890. Essentially, this macro changes the current directory to @var{directory}
  6891. before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
  6892. guile, GNU Guile Reference Manual}). It changes back to the initial
  6893. directory when the dynamic extent of @var{body} is left, be it @i{via}
  6894. normal procedure return or @i{via} a non-local exit such as an
  6895. exception.
  6896. @end deffn
  6897. @deffn {Scheme Procedure} mkdir-p @var{dir}
  6898. Create directory @var{dir} and all its ancestors.
  6899. @end deffn
  6900. @deffn {Scheme Procedure} install-file @var{file} @var{directory}
  6901. Create @var{directory} if it does not exist and copy @var{file} in there
  6902. under the same name.
  6903. @end deffn
  6904. @deffn {Scheme Procedure} make-file-writable @var{file}
  6905. Make @var{file} writable for its owner.
  6906. @end deffn
  6907. @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
  6908. [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
  6909. Copy @var{source} directory to @var{destination}. Follow symlinks if
  6910. @var{follow-symlinks?} is true; otherwise, just preserve them. When
  6911. @var{keep-mtime?} is true, keep the modification time of the files in
  6912. @var{source} on those of @var{destination}. Write verbose output to the
  6913. @var{log} port.
  6914. @end deffn
  6915. @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
  6916. [#:follow-mounts? #f]
  6917. Delete @var{dir} recursively, like @command{rm -rf}, without following
  6918. symlinks. Don't follow mount points either, unless @var{follow-mounts?}
  6919. is true. Report but ignore errors.
  6920. @end deffn
  6921. @deffn {Scheme Syntax} substitute* @var{file} @
  6922. ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
  6923. Substitute @var{regexp} in @var{file} by the string returned by
  6924. @var{body}. @var{body} is evaluated with each @var{match-var} bound to
  6925. the corresponding positional regexp sub-expression. For example:
  6926. @lisp
  6927. (substitute* file
  6928. (("hello")
  6929. "good morning\n")
  6930. (("foo([a-z]+)bar(.*)$" all letters end)
  6931. (string-append "baz" letter end)))
  6932. @end lisp
  6933. Here, anytime a line of @var{file} contains @code{hello}, it is replaced
  6934. by @code{good morning}. Anytime a line of @var{file} matches the second
  6935. regexp, @code{all} is bound to the complete match, @code{letters} is bound
  6936. to the first sub-expression, and @code{end} is bound to the last one.
  6937. When one of the @var{match-var} is @code{_}, no variable is bound to the
  6938. corresponding match substring.
  6939. Alternatively, @var{file} may be a list of file names, in which case
  6940. they are all subject to the substitutions.
  6941. Be careful about using @code{$} to match the end of a line; by itself it
  6942. won't match the terminating newline of a line.
  6943. @end deffn
  6944. @subsection File Search
  6945. @cindex file, searching
  6946. This section documents procedures to search and filter files.
  6947. @deffn {Scheme Procedure} file-name-predicate @var{regexp}
  6948. Return a predicate that returns true when passed a file name whose base
  6949. name matches @var{regexp}.
  6950. @end deffn
  6951. @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
  6952. [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
  6953. Return the lexicographically sorted list of files under @var{dir} for
  6954. which @var{pred} returns true. @var{pred} is passed two arguments: the
  6955. absolute file name, and its stat buffer; the default predicate always
  6956. returns true. @var{pred} can also be a regular expression, in which
  6957. case it is equivalent to @code{(file-name-predicate @var{pred})}.
  6958. @var{stat} is used to obtain file information; using @code{lstat} means
  6959. that symlinks are not followed. If @var{directories?} is true, then
  6960. directories will also be included. If @var{fail-on-error?} is true,
  6961. raise an exception upon error.
  6962. @end deffn
  6963. Here are a few examples where we assume that the current directory is
  6964. the root of the Guix source tree:
  6965. @lisp
  6966. ;; List all the regular files in the current directory.
  6967. (find-files ".")
  6968. @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
  6969. ;; List all the .scm files under gnu/services.
  6970. (find-files "gnu/services" "\\.scm$")
  6971. @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
  6972. ;; List ar files in the current directory.
  6973. (find-files "." (lambda (file stat) (ar-file? file)))
  6974. @result{} ("./libformat.a" "./libstore.a" @dots{})
  6975. @end lisp
  6976. @deffn {Scheme Procedure} which @var{program}
  6977. Return the complete file name for @var{program} as found in
  6978. @code{$PATH}, or @code{#f} if @var{program} could not be found.
  6979. @end deffn
  6980. @subsection Build Phases
  6981. @cindex build phases
  6982. The @code{(guix build utils)} also contains tools to manipulate build
  6983. phases as used by build systems (@pxref{Build Systems}). Build phases
  6984. are represented as association lists or ``alists'' (@pxref{Association
  6985. Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
  6986. naming the phase and the associated value is a procedure (@pxref{Build
  6987. Phases}).
  6988. Guile core and the @code{(srfi srfi-1)} module both provide tools to
  6989. manipulate alists. The @code{(guix build utils)} module complements
  6990. those with tools written with build phases in mind.
  6991. @cindex build phases, modifying
  6992. @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
  6993. Modify @var{phases} sequentially as per each @var{clause}, which may
  6994. have one of the following forms:
  6995. @lisp
  6996. (delete @var{old-phase-name})
  6997. (replace @var{old-phase-name} @var{new-phase})
  6998. (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
  6999. (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
  7000. @end lisp
  7001. Where every @var{phase-name} above is an expression evaluating to a
  7002. symbol, and @var{new-phase} an expression evaluating to a procedure.
  7003. @end deffn
  7004. The example below is taken from the definition of the @code{grep}
  7005. package. It adds a phase to run after the @code{install} phase, called
  7006. @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
  7007. is for anonymous procedures) that takes a @code{#:outputs} keyword
  7008. argument and ignores extra keyword arguments (@pxref{Optional
  7009. Arguments,,, guile, GNU Guile Reference Manual}, for more on
  7010. @code{lambda*} and optional and keyword arguments.) The phase uses
  7011. @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
  7012. scripts so that they refer to @code{grep} by its absolute file name:
  7013. @lisp
  7014. (modify-phases %standard-phases
  7015. (add-after 'install 'fix-egrep-and-fgrep
  7016. ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
  7017. ;; absolute file name instead of searching for it in $PATH.
  7018. (lambda* (#:key outputs #:allow-other-keys)
  7019. (let* ((out (assoc-ref outputs "out"))
  7020. (bin (string-append out "/bin")))
  7021. (substitute* (list (string-append bin "/egrep")
  7022. (string-append bin "/fgrep"))
  7023. (("^exec grep")
  7024. (string-append "exec " bin "/grep")))
  7025. #t))))
  7026. @end lisp
  7027. In the example below, phases are modified in two ways: the standard
  7028. @code{configure} phase is deleted, presumably because the package does
  7029. not have a @file{configure} script or anything similar, and the default
  7030. @code{install} phase is replaced by one that manually copies the
  7031. executable files to be installed:
  7032. @lisp
  7033. (modify-phases %standard-phases
  7034. (delete 'configure) ;no 'configure' script
  7035. (replace 'install
  7036. (lambda* (#:key outputs #:allow-other-keys)
  7037. ;; The package's Makefile doesn't provide an "install"
  7038. ;; rule so do it by ourselves.
  7039. (let ((bin (string-append (assoc-ref outputs "out")
  7040. "/bin")))
  7041. (install-file "footswitch" bin)
  7042. (install-file "scythe" bin)
  7043. #t))))
  7044. @end lisp
  7045. @c TODO: Add more examples.
  7046. @node The Store
  7047. @section The Store
  7048. @cindex store
  7049. @cindex store items
  7050. @cindex store paths
  7051. Conceptually, the @dfn{store} is the place where derivations that have
  7052. been built successfully are stored---by default, @file{/gnu/store}.
  7053. Sub-directories in the store are referred to as @dfn{store items} or
  7054. sometimes @dfn{store paths}. The store has an associated database that
  7055. contains information such as the store paths referred to by each store
  7056. path, and the list of @emph{valid} store items---results of successful
  7057. builds. This database resides in @file{@var{localstatedir}/guix/db},
  7058. where @var{localstatedir} is the state directory specified @i{via}
  7059. @option{--localstatedir} at configure time, usually @file{/var}.
  7060. The store is @emph{always} accessed by the daemon on behalf of its clients
  7061. (@pxref{Invoking guix-daemon}). To manipulate the store, clients
  7062. connect to the daemon over a Unix-domain socket, send requests to it,
  7063. and read the result---these are remote procedure calls, or RPCs.
  7064. @quotation Note
  7065. Users must @emph{never} modify files under @file{/gnu/store} directly.
  7066. This would lead to inconsistencies and break the immutability
  7067. assumptions of Guix's functional model (@pxref{Introduction}).
  7068. @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
  7069. how to check the integrity of the store and attempt recovery from
  7070. accidental modifications.
  7071. @end quotation
  7072. The @code{(guix store)} module provides procedures to connect to the
  7073. daemon, and to perform RPCs. These are described below. By default,
  7074. @code{open-connection}, and thus all the @command{guix} commands,
  7075. connect to the local daemon or to the URI specified by the
  7076. @env{GUIX_DAEMON_SOCKET} environment variable.
  7077. @defvr {Environment Variable} GUIX_DAEMON_SOCKET
  7078. When set, the value of this variable should be a file name or a URI
  7079. designating the daemon endpoint. When it is a file name, it denotes a
  7080. Unix-domain socket to connect to. In addition to file names, the
  7081. supported URI schemes are:
  7082. @table @code
  7083. @item file
  7084. @itemx unix
  7085. These are for Unix-domain sockets.
  7086. @code{file:///var/guix/daemon-socket/socket} is equivalent to
  7087. @file{/var/guix/daemon-socket/socket}.
  7088. @item guix
  7089. @cindex daemon, remote access
  7090. @cindex remote access to the daemon
  7091. @cindex daemon, cluster setup
  7092. @cindex clusters, daemon setup
  7093. These URIs denote connections over TCP/IP, without encryption nor
  7094. authentication of the remote host. The URI must specify the host name
  7095. and optionally a port number (by default port 44146 is used):
  7096. @example
  7097. guix://master.guix.example.org:1234
  7098. @end example
  7099. This setup is suitable on local networks, such as clusters, where only
  7100. trusted nodes may connect to the build daemon at
  7101. @code{master.guix.example.org}.
  7102. The @option{--listen} option of @command{guix-daemon} can be used to
  7103. instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
  7104. @option{--listen}}).
  7105. @item ssh
  7106. @cindex SSH access to build daemons
  7107. These URIs allow you to connect to a remote daemon over SSH@. This
  7108. feature requires Guile-SSH (@pxref{Requirements}) and a working
  7109. @command{guile} binary in @env{PATH} on the destination machine. It
  7110. supports public key and GSSAPI authentication. A typical URL might look
  7111. like this:
  7112. @example
  7113. ssh://charlie@@guix.example.org:22
  7114. @end example
  7115. As for @command{guix copy}, the usual OpenSSH client configuration files
  7116. are honored (@pxref{Invoking guix copy}).
  7117. @end table
  7118. Additional URI schemes may be supported in the future.
  7119. @c XXX: Remove this note when the protocol incurs fewer round trips
  7120. @c and when (guix derivations) no longer relies on file system access.
  7121. @quotation Note
  7122. The ability to connect to remote build daemons is considered
  7123. experimental as of @value{VERSION}. Please get in touch with us to
  7124. share any problems or suggestions you may have (@pxref{Contributing}).
  7125. @end quotation
  7126. @end defvr
  7127. @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
  7128. Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
  7129. @var{reserve-space?} is true, instruct it to reserve a little bit of
  7130. extra space on the file system so that the garbage collector can still
  7131. operate should the disk become full. Return a server object.
  7132. @var{file} defaults to @code{%default-socket-path}, which is the normal
  7133. location given the options that were passed to @command{configure}.
  7134. @end deffn
  7135. @deffn {Scheme Procedure} close-connection @var{server}
  7136. Close the connection to @var{server}.
  7137. @end deffn
  7138. @defvr {Scheme Variable} current-build-output-port
  7139. This variable is bound to a SRFI-39 parameter, which refers to the port
  7140. where build and error logs sent by the daemon should be written.
  7141. @end defvr
  7142. Procedures that make RPCs all take a server object as their first
  7143. argument.
  7144. @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
  7145. @cindex invalid store items
  7146. Return @code{#t} when @var{path} designates a valid store item and
  7147. @code{#f} otherwise (an invalid item may exist on disk but still be
  7148. invalid, for instance because it is the result of an aborted or failed
  7149. build).
  7150. A @code{&store-protocol-error} condition is raised if @var{path} is not
  7151. prefixed by the store directory (@file{/gnu/store}).
  7152. @end deffn
  7153. @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
  7154. Add @var{text} under file @var{name} in the store, and return its store
  7155. path. @var{references} is the list of store paths referred to by the
  7156. resulting store path.
  7157. @end deffn
  7158. @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
  7159. [@var{mode}]
  7160. Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
  7161. file names, or derivation/output pairs, using the specified
  7162. @var{mode}---@code{(build-mode normal)} by default.
  7163. @end deffn
  7164. Note that the @code{(guix monads)} module provides a monad as well as
  7165. monadic versions of the above procedures, with the goal of making it
  7166. more convenient to work with code that accesses the store (@pxref{The
  7167. Store Monad}).
  7168. @c FIXME
  7169. @i{This section is currently incomplete.}
  7170. @node Derivations
  7171. @section Derivations
  7172. @cindex derivations
  7173. Low-level build actions and the environment in which they are performed
  7174. are represented by @dfn{derivations}. A derivation contains the
  7175. following pieces of information:
  7176. @itemize
  7177. @item
  7178. The outputs of the derivation---derivations produce at least one file or
  7179. directory in the store, but may produce more.
  7180. @item
  7181. @cindex build-time dependencies
  7182. @cindex dependencies, build-time
  7183. The inputs of the derivations---i.e., its build-time dependencies---which may
  7184. be other derivations or plain files in the store (patches, build scripts,
  7185. etc.).
  7186. @item
  7187. The system type targeted by the derivation---e.g., @code{x86_64-linux}.
  7188. @item
  7189. The file name of a build script in the store, along with the arguments
  7190. to be passed.
  7191. @item
  7192. A list of environment variables to be defined.
  7193. @end itemize
  7194. @cindex derivation path
  7195. Derivations allow clients of the daemon to communicate build actions to
  7196. the store. They exist in two forms: as an in-memory representation,
  7197. both on the client- and daemon-side, and as files in the store whose
  7198. name end in @file{.drv}---these files are referred to as @dfn{derivation
  7199. paths}. Derivations paths can be passed to the @code{build-derivations}
  7200. procedure to perform the build actions they prescribe (@pxref{The
  7201. Store}).
  7202. @cindex fixed-output derivations
  7203. Operations such as file downloads and version-control checkouts for
  7204. which the expected content hash is known in advance are modeled as
  7205. @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
  7206. of a fixed-output derivation are independent of its inputs---e.g., a
  7207. source code download produces the same result regardless of the download
  7208. method and tools being used.
  7209. @cindex references
  7210. @cindex run-time dependencies
  7211. @cindex dependencies, run-time
  7212. The outputs of derivations---i.e., the build results---have a set of
  7213. @dfn{references}, as reported by the @code{references} RPC or the
  7214. @command{guix gc --references} command (@pxref{Invoking guix gc}). References
  7215. are the set of run-time dependencies of the build results. References are a
  7216. subset of the inputs of the derivation; this subset is automatically computed
  7217. by the build daemon by scanning all the files in the outputs.
  7218. The @code{(guix derivations)} module provides a representation of
  7219. derivations as Scheme objects, along with procedures to create and
  7220. otherwise manipulate derivations. The lowest-level primitive to create
  7221. a derivation is the @code{derivation} procedure:
  7222. @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
  7223. @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
  7224. [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
  7225. [#:system (%current-system)] [#:references-graphs #f] @
  7226. [#:allowed-references #f] [#:disallowed-references #f] @
  7227. [#:leaked-env-vars #f] [#:local-build? #f] @
  7228. [#:substitutable? #t] [#:properties '()]
  7229. Build a derivation with the given arguments, and return the resulting
  7230. @code{<derivation>} object.
  7231. When @var{hash} and @var{hash-algo} are given, a
  7232. @dfn{fixed-output derivation} is created---i.e., one whose result is
  7233. known in advance, such as a file download. If, in addition,
  7234. @var{recursive?} is true, then that fixed output may be an executable
  7235. file or a directory and @var{hash} must be the hash of an archive
  7236. containing this output.
  7237. When @var{references-graphs} is true, it must be a list of file
  7238. name/store path pairs. In that case, the reference graph of each store
  7239. path is exported in the build environment in the corresponding file, in
  7240. a simple text format.
  7241. When @var{allowed-references} is true, it must be a list of store items
  7242. or outputs that the derivation's output may refer to. Likewise,
  7243. @var{disallowed-references}, if true, must be a list of things the
  7244. outputs may @emph{not} refer to.
  7245. When @var{leaked-env-vars} is true, it must be a list of strings
  7246. denoting environment variables that are allowed to ``leak'' from the
  7247. daemon's environment to the build environment. This is only applicable
  7248. to fixed-output derivations---i.e., when @var{hash} is true. The main
  7249. use is to allow variables such as @code{http_proxy} to be passed to
  7250. derivations that download files.
  7251. When @var{local-build?} is true, declare that the derivation is not a
  7252. good candidate for offloading and should rather be built locally
  7253. (@pxref{Daemon Offload Setup}). This is the case for small derivations
  7254. where the costs of data transfers would outweigh the benefits.
  7255. When @var{substitutable?} is false, declare that substitutes of the
  7256. derivation's output should not be used (@pxref{Substitutes}). This is
  7257. useful, for instance, when building packages that capture details of the
  7258. host CPU instruction set.
  7259. @var{properties} must be an association list describing ``properties'' of the
  7260. derivation. It is kept as-is, uninterpreted, in the derivation.
  7261. @end deffn
  7262. @noindent
  7263. Here's an example with a shell script as its builder, assuming
  7264. @var{store} is an open connection to the daemon, and @var{bash} points
  7265. to a Bash executable in the store:
  7266. @lisp
  7267. (use-modules (guix utils)
  7268. (guix store)
  7269. (guix derivations))
  7270. (let ((builder ; add the Bash script to the store
  7271. (add-text-to-store store "my-builder.sh"
  7272. "echo hello world > $out\n" '())))
  7273. (derivation store "foo"
  7274. bash `("-e" ,builder)
  7275. #:inputs `((,bash) (,builder))
  7276. #:env-vars '(("HOME" . "/homeless"))))
  7277. @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
  7278. @end lisp
  7279. As can be guessed, this primitive is cumbersome to use directly. A
  7280. better approach is to write build scripts in Scheme, of course! The
  7281. best course of action for that is to write the build code as a
  7282. ``G-expression'', and to pass it to @code{gexp->derivation}. For more
  7283. information, @pxref{G-Expressions}.
  7284. Once upon a time, @code{gexp->derivation} did not exist and constructing
  7285. derivations with build code written in Scheme was achieved with
  7286. @code{build-expression->derivation}, documented below. This procedure
  7287. is now deprecated in favor of the much nicer @code{gexp->derivation}.
  7288. @deffn {Scheme Procedure} build-expression->derivation @var{store} @
  7289. @var{name} @var{exp} @
  7290. [#:system (%current-system)] [#:inputs '()] @
  7291. [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
  7292. [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
  7293. [#:references-graphs #f] [#:allowed-references #f] @
  7294. [#:disallowed-references #f] @
  7295. [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
  7296. Return a derivation that executes Scheme expression @var{exp} as a
  7297. builder for derivation @var{name}. @var{inputs} must be a list of
  7298. @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
  7299. @code{"out"} is assumed. @var{modules} is a list of names of Guile
  7300. modules from the current search path to be copied in the store,
  7301. compiled, and made available in the load path during the execution of
  7302. @var{exp}---e.g., @code{((guix build utils) (guix build
  7303. gnu-build-system))}.
  7304. @var{exp} is evaluated in an environment where @code{%outputs} is bound
  7305. to a list of output/path pairs, and where @code{%build-inputs} is bound
  7306. to a list of string/output-path pairs made from @var{inputs}.
  7307. Optionally, @var{env-vars} is a list of string pairs specifying the name
  7308. and value of environment variables visible to the builder. The builder
  7309. terminates by passing the result of @var{exp} to @code{exit}; thus, when
  7310. @var{exp} returns @code{#f}, the build is considered to have failed.
  7311. @var{exp} is built using @var{guile-for-build} (a derivation). When
  7312. @var{guile-for-build} is omitted or is @code{#f}, the value of the
  7313. @code{%guile-for-build} fluid is used instead.
  7314. See the @code{derivation} procedure for the meaning of
  7315. @var{references-graphs}, @var{allowed-references},
  7316. @var{disallowed-references}, @var{local-build?}, and
  7317. @var{substitutable?}.
  7318. @end deffn
  7319. @noindent
  7320. Here's an example of a single-output derivation that creates a directory
  7321. containing one file:
  7322. @lisp
  7323. (let ((builder '(let ((out (assoc-ref %outputs "out")))
  7324. (mkdir out) ; create /gnu/store/@dots{}-goo
  7325. (call-with-output-file (string-append out "/test")
  7326. (lambda (p)
  7327. (display '(hello guix) p))))))
  7328. (build-expression->derivation store "goo" builder))
  7329. @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
  7330. @end lisp
  7331. @node The Store Monad
  7332. @section The Store Monad
  7333. @cindex monad
  7334. The procedures that operate on the store described in the previous
  7335. sections all take an open connection to the build daemon as their first
  7336. argument. Although the underlying model is functional, they either have
  7337. side effects or depend on the current state of the store.
  7338. The former is inconvenient: the connection to the build daemon has to be
  7339. carried around in all those functions, making it impossible to compose
  7340. functions that do not take that parameter with functions that do. The
  7341. latter can be problematic: since store operations have side effects
  7342. and/or depend on external state, they have to be properly sequenced.
  7343. @cindex monadic values
  7344. @cindex monadic functions
  7345. This is where the @code{(guix monads)} module comes in. This module
  7346. provides a framework for working with @dfn{monads}, and a particularly
  7347. useful monad for our uses, the @dfn{store monad}. Monads are a
  7348. construct that allows two things: associating ``context'' with values
  7349. (in our case, the context is the store), and building sequences of
  7350. computations (here computations include accesses to the store). Values
  7351. in a monad---values that carry this additional context---are called
  7352. @dfn{monadic values}; procedures that return such values are called
  7353. @dfn{monadic procedures}.
  7354. Consider this ``normal'' procedure:
  7355. @lisp
  7356. (define (sh-symlink store)
  7357. ;; Return a derivation that symlinks the 'bash' executable.
  7358. (let* ((drv (package-derivation store bash))
  7359. (out (derivation->output-path drv))
  7360. (sh (string-append out "/bin/bash")))
  7361. (build-expression->derivation store "sh"
  7362. `(symlink ,sh %output))))
  7363. @end lisp
  7364. Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
  7365. as a monadic function:
  7366. @lisp
  7367. (define (sh-symlink)
  7368. ;; Same, but return a monadic value.
  7369. (mlet %store-monad ((drv (package->derivation bash)))
  7370. (gexp->derivation "sh"
  7371. #~(symlink (string-append #$drv "/bin/bash")
  7372. #$output))))
  7373. @end lisp
  7374. There are several things to note in the second version: the @code{store}
  7375. parameter is now implicit and is ``threaded'' in the calls to the
  7376. @code{package->derivation} and @code{gexp->derivation} monadic
  7377. procedures, and the monadic value returned by @code{package->derivation}
  7378. is @dfn{bound} using @code{mlet} instead of plain @code{let}.
  7379. As it turns out, the call to @code{package->derivation} can even be
  7380. omitted since it will take place implicitly, as we will see later
  7381. (@pxref{G-Expressions}):
  7382. @lisp
  7383. (define (sh-symlink)
  7384. (gexp->derivation "sh"
  7385. #~(symlink (string-append #$bash "/bin/bash")
  7386. #$output)))
  7387. @end lisp
  7388. @c See
  7389. @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
  7390. @c for the funny quote.
  7391. Calling the monadic @code{sh-symlink} has no effect. As someone once
  7392. said, ``you exit a monad like you exit a building on fire: by running''.
  7393. So, to exit the monad and get the desired effect, one must use
  7394. @code{run-with-store}:
  7395. @lisp
  7396. (run-with-store (open-connection) (sh-symlink))
  7397. @result{} /gnu/store/...-sh-symlink
  7398. @end lisp
  7399. Note that the @code{(guix monad-repl)} module extends the Guile REPL with
  7400. new ``meta-commands'' to make it easier to deal with monadic procedures:
  7401. @code{run-in-store}, and @code{enter-store-monad}. The former is used
  7402. to ``run'' a single monadic value through the store:
  7403. @example
  7404. scheme@@(guile-user)> ,run-in-store (package->derivation hello)
  7405. $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
  7406. @end example
  7407. The latter enters a recursive REPL, where all the return values are
  7408. automatically run through the store:
  7409. @example
  7410. scheme@@(guile-user)> ,enter-store-monad
  7411. store-monad@@(guile-user) [1]> (package->derivation hello)
  7412. $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
  7413. store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
  7414. $3 = "/gnu/store/@dots{}-foo"
  7415. store-monad@@(guile-user) [1]> ,q
  7416. scheme@@(guile-user)>
  7417. @end example
  7418. @noindent
  7419. Note that non-monadic values cannot be returned in the
  7420. @code{store-monad} REPL.
  7421. The main syntactic forms to deal with monads in general are provided by
  7422. the @code{(guix monads)} module and are described below.
  7423. @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
  7424. Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
  7425. in @var{monad}.
  7426. @end deffn
  7427. @deffn {Scheme Syntax} return @var{val}
  7428. Return a monadic value that encapsulates @var{val}.
  7429. @end deffn
  7430. @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
  7431. @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
  7432. procedures @var{mproc}@dots{}@footnote{This operation is commonly
  7433. referred to as ``bind'', but that name denotes an unrelated procedure in
  7434. Guile. Thus we use this somewhat cryptic symbol inherited from the
  7435. Haskell language.}. There can be one @var{mproc} or several of them, as
  7436. in this example:
  7437. @lisp
  7438. (run-with-state
  7439. (with-monad %state-monad
  7440. (>>= (return 1)
  7441. (lambda (x) (return (+ 1 x)))
  7442. (lambda (x) (return (* 2 x)))))
  7443. 'some-state)
  7444. @result{} 4
  7445. @result{} some-state
  7446. @end lisp
  7447. @end deffn
  7448. @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
  7449. @var{body} ...
  7450. @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
  7451. @var{body} ...
  7452. Bind the variables @var{var} to the monadic values @var{mval} in
  7453. @var{body}, which is a sequence of expressions. As with the bind
  7454. operator, this can be thought of as ``unpacking'' the raw, non-monadic
  7455. value ``contained'' in @var{mval} and making @var{var} refer to that
  7456. raw, non-monadic value within the scope of the @var{body}. The form
  7457. (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
  7458. @var{val}, as per @code{let}. The binding operations occur in sequence
  7459. from left to right. The last expression of @var{body} must be a monadic
  7460. expression, and its result will become the result of the @code{mlet} or
  7461. @code{mlet*} when run in the @var{monad}.
  7462. @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
  7463. (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
  7464. @end deffn
  7465. @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
  7466. Bind @var{mexp} and the following monadic expressions in sequence,
  7467. returning the result of the last expression. Every expression in the
  7468. sequence must be a monadic expression.
  7469. This is akin to @code{mlet}, except that the return values of the
  7470. monadic expressions are ignored. In that sense, it is analogous to
  7471. @code{begin}, but applied to monadic expressions.
  7472. @end deffn
  7473. @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
  7474. When @var{condition} is true, evaluate the sequence of monadic
  7475. expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
  7476. @var{condition} is false, return @code{*unspecified*} in the current
  7477. monad. Every expression in the sequence must be a monadic expression.
  7478. @end deffn
  7479. @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
  7480. When @var{condition} is false, evaluate the sequence of monadic
  7481. expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
  7482. @var{condition} is true, return @code{*unspecified*} in the current
  7483. monad. Every expression in the sequence must be a monadic expression.
  7484. @end deffn
  7485. @cindex state monad
  7486. The @code{(guix monads)} module provides the @dfn{state monad}, which
  7487. allows an additional value---the state---to be @emph{threaded} through
  7488. monadic procedure calls.
  7489. @defvr {Scheme Variable} %state-monad
  7490. The state monad. Procedures in the state monad can access and change
  7491. the state that is threaded.
  7492. Consider the example below. The @code{square} procedure returns a value
  7493. in the state monad. It returns the square of its argument, but also
  7494. increments the current state value:
  7495. @lisp
  7496. (define (square x)
  7497. (mlet %state-monad ((count (current-state)))
  7498. (mbegin %state-monad
  7499. (set-current-state (+ 1 count))
  7500. (return (* x x)))))
  7501. (run-with-state (sequence %state-monad (map square (iota 3))) 0)
  7502. @result{} (0 1 4)
  7503. @result{} 3
  7504. @end lisp
  7505. When ``run'' through @code{%state-monad}, we obtain that additional state
  7506. value, which is the number of @code{square} calls.
  7507. @end defvr
  7508. @deffn {Monadic Procedure} current-state
  7509. Return the current state as a monadic value.
  7510. @end deffn
  7511. @deffn {Monadic Procedure} set-current-state @var{value}
  7512. Set the current state to @var{value} and return the previous state as a
  7513. monadic value.
  7514. @end deffn
  7515. @deffn {Monadic Procedure} state-push @var{value}
  7516. Push @var{value} to the current state, which is assumed to be a list,
  7517. and return the previous state as a monadic value.
  7518. @end deffn
  7519. @deffn {Monadic Procedure} state-pop
  7520. Pop a value from the current state and return it as a monadic value.
  7521. The state is assumed to be a list.
  7522. @end deffn
  7523. @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
  7524. Run monadic value @var{mval} starting with @var{state} as the initial
  7525. state. Return two values: the resulting value, and the resulting state.
  7526. @end deffn
  7527. The main interface to the store monad, provided by the @code{(guix
  7528. store)} module, is as follows.
  7529. @defvr {Scheme Variable} %store-monad
  7530. The store monad---an alias for @code{%state-monad}.
  7531. Values in the store monad encapsulate accesses to the store. When its
  7532. effect is needed, a value of the store monad must be ``evaluated'' by
  7533. passing it to the @code{run-with-store} procedure (see below).
  7534. @end defvr
  7535. @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
  7536. Run @var{mval}, a monadic value in the store monad, in @var{store}, an
  7537. open store connection.
  7538. @end deffn
  7539. @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
  7540. Return as a monadic value the absolute file name in the store of the file
  7541. containing @var{text}, a string. @var{references} is a list of store items that the
  7542. resulting text file refers to; it defaults to the empty list.
  7543. @end deffn
  7544. @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
  7545. Return as a monadic value the absolute file name in the store of the file
  7546. containing @var{data}, a bytevector. @var{references} is a list of store
  7547. items that the resulting binary file refers to; it defaults to the empty list.
  7548. @end deffn
  7549. @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
  7550. [#:recursive? #t] [#:select? (const #t)]
  7551. Return the name of @var{file} once interned in the store. Use
  7552. @var{name} as its store name, or the basename of @var{file} if
  7553. @var{name} is omitted.
  7554. When @var{recursive?} is true, the contents of @var{file} are added
  7555. recursively; if @var{file} designates a flat file and @var{recursive?}
  7556. is true, its contents are added, and its permission bits are kept.
  7557. When @var{recursive?} is true, call @code{(@var{select?} @var{file}
  7558. @var{stat})} for each directory entry, where @var{file} is the entry's
  7559. absolute file name and @var{stat} is the result of @code{lstat}; exclude
  7560. entries for which @var{select?} does not return true.
  7561. The example below adds a file to the store, under two different names:
  7562. @lisp
  7563. (run-with-store (open-connection)
  7564. (mlet %store-monad ((a (interned-file "README"))
  7565. (b (interned-file "README" "LEGU-MIN")))
  7566. (return (list a b))))
  7567. @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
  7568. @end lisp
  7569. @end deffn
  7570. The @code{(guix packages)} module exports the following package-related
  7571. monadic procedures:
  7572. @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
  7573. [#:system (%current-system)] [#:target #f] @
  7574. [#:output "out"]
  7575. Return as a monadic
  7576. value in the absolute file name of @var{file} within the @var{output}
  7577. directory of @var{package}. When @var{file} is omitted, return the name
  7578. of the @var{output} directory of @var{package}. When @var{target} is
  7579. true, use it as a cross-compilation target triplet.
  7580. Note that this procedure does @emph{not} build @var{package}. Thus, the
  7581. result might or might not designate an existing file. We recommend not
  7582. using this procedure unless you know what you are doing.
  7583. @end deffn
  7584. @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
  7585. @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
  7586. @var{target} [@var{system}]
  7587. Monadic version of @code{package-derivation} and
  7588. @code{package-cross-derivation} (@pxref{Defining Packages}).
  7589. @end deffn
  7590. @node G-Expressions
  7591. @section G-Expressions
  7592. @cindex G-expression
  7593. @cindex build code quoting
  7594. So we have ``derivations'', which represent a sequence of build actions
  7595. to be performed to produce an item in the store (@pxref{Derivations}).
  7596. These build actions are performed when asking the daemon to actually
  7597. build the derivations; they are run by the daemon in a container
  7598. (@pxref{Invoking guix-daemon}).
  7599. @cindex code staging
  7600. @cindex staging, of code
  7601. @cindex strata of code
  7602. It should come as no surprise that we like to write these build actions
  7603. in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
  7604. code@footnote{The term @dfn{stratum} in this context was coined by
  7605. Manuel Serrano et al.@: in the context of their work on Hop. Oleg
  7606. Kiselyov, who has written insightful
  7607. @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
  7608. on this topic}, refers to this kind of code generation as
  7609. @dfn{staging}.}: the ``host code''---code that defines packages, talks
  7610. to the daemon, etc.---and the ``build code''---code that actually
  7611. performs build actions, such as making directories, invoking
  7612. @command{make}, and so on (@pxref{Build Phases}).
  7613. To describe a derivation and its build actions, one typically needs to
  7614. embed build code inside host code. It boils down to manipulating build
  7615. code as data, and the homoiconicity of Scheme---code has a direct
  7616. representation as data---comes in handy for that. But we need more than
  7617. the normal @code{quasiquote} mechanism in Scheme to construct build
  7618. expressions.
  7619. The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
  7620. S-expressions adapted to build expressions. G-expressions, or
  7621. @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
  7622. @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
  7623. @code{#$}, and @code{#$@@}), which are comparable to
  7624. @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
  7625. respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
  7626. GNU Guile Reference Manual}). However, there are major differences:
  7627. @itemize
  7628. @item
  7629. Gexps are meant to be written to a file and run or manipulated by other
  7630. processes.
  7631. @item
  7632. When a high-level object such as a package or derivation is unquoted
  7633. inside a gexp, the result is as if its output file name had been
  7634. introduced.
  7635. @item
  7636. Gexps carry information about the packages or derivations they refer to,
  7637. and these dependencies are automatically added as inputs to the build
  7638. processes that use them.
  7639. @end itemize
  7640. @cindex lowering, of high-level objects in gexps
  7641. This mechanism is not limited to package and derivation
  7642. objects: @dfn{compilers} able to ``lower'' other high-level objects to
  7643. derivations or files in the store can be defined,
  7644. such that these objects can also be inserted
  7645. into gexps. For example, a useful type of high-level objects that can be
  7646. inserted in a gexp is ``file-like objects'', which make it easy to
  7647. add files to the store and to refer to them in
  7648. derivations and such (see @code{local-file} and @code{plain-file}
  7649. below).
  7650. To illustrate the idea, here is an example of a gexp:
  7651. @lisp
  7652. (define build-exp
  7653. #~(begin
  7654. (mkdir #$output)
  7655. (chdir #$output)
  7656. (symlink (string-append #$coreutils "/bin/ls")
  7657. "list-files")))
  7658. @end lisp
  7659. This gexp can be passed to @code{gexp->derivation}; we obtain a
  7660. derivation that builds a directory containing exactly one symlink to
  7661. @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
  7662. @lisp
  7663. (gexp->derivation "the-thing" build-exp)
  7664. @end lisp
  7665. As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
  7666. substituted to the reference to the @var{coreutils} package in the
  7667. actual build code, and @var{coreutils} is automatically made an input to
  7668. the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
  7669. output)}) is replaced by a string containing the directory name of the
  7670. output of the derivation.
  7671. @cindex cross compilation
  7672. In a cross-compilation context, it is useful to distinguish between
  7673. references to the @emph{native} build of a package---that can run on the
  7674. host---versus references to cross builds of a package. To that end, the
  7675. @code{#+} plays the same role as @code{#$}, but is a reference to a
  7676. native package build:
  7677. @lisp
  7678. (gexp->derivation "vi"
  7679. #~(begin
  7680. (mkdir #$output)
  7681. (mkdir (string-append #$output "/bin"))
  7682. (system* (string-append #+coreutils "/bin/ln")
  7683. "-s"
  7684. (string-append #$emacs "/bin/emacs")
  7685. (string-append #$output "/bin/vi")))
  7686. #:target "aarch64-linux-gnu")
  7687. @end lisp
  7688. @noindent
  7689. In the example above, the native build of @var{coreutils} is used, so
  7690. that @command{ln} can actually run on the host; but then the
  7691. cross-compiled build of @var{emacs} is referenced.
  7692. @cindex imported modules, for gexps
  7693. @findex with-imported-modules
  7694. Another gexp feature is @dfn{imported modules}: sometimes you want to be
  7695. able to use certain Guile modules from the ``host environment'' in the
  7696. gexp, so those modules should be imported in the ``build environment''.
  7697. The @code{with-imported-modules} form allows you to express that:
  7698. @lisp
  7699. (let ((build (with-imported-modules '((guix build utils))
  7700. #~(begin
  7701. (use-modules (guix build utils))
  7702. (mkdir-p (string-append #$output "/bin"))))))
  7703. (gexp->derivation "empty-dir"
  7704. #~(begin
  7705. #$build
  7706. (display "success!\n")
  7707. #t)))
  7708. @end lisp
  7709. @noindent
  7710. In this example, the @code{(guix build utils)} module is automatically
  7711. pulled into the isolated build environment of our gexp, such that
  7712. @code{(use-modules (guix build utils))} works as expected.
  7713. @cindex module closure
  7714. @findex source-module-closure
  7715. Usually you want the @emph{closure} of the module to be imported---i.e.,
  7716. the module itself and all the modules it depends on---rather than just
  7717. the module; failing to do that, attempts to use the module will fail
  7718. because of missing dependent modules. The @code{source-module-closure}
  7719. procedure computes the closure of a module by looking at its source file
  7720. headers, which comes in handy in this case:
  7721. @lisp
  7722. (use-modules (guix modules)) ;for 'source-module-closure'
  7723. (with-imported-modules (source-module-closure
  7724. '((guix build utils)
  7725. (gnu build vm)))
  7726. (gexp->derivation "something-with-vms"
  7727. #~(begin
  7728. (use-modules (guix build utils)
  7729. (gnu build vm))
  7730. @dots{})))
  7731. @end lisp
  7732. @cindex extensions, for gexps
  7733. @findex with-extensions
  7734. In the same vein, sometimes you want to import not just pure-Scheme
  7735. modules, but also ``extensions'' such as Guile bindings to C libraries
  7736. or other ``full-blown'' packages. Say you need the @code{guile-json}
  7737. package available on the build side, here's how you would do it:
  7738. @lisp
  7739. (use-modules (gnu packages guile)) ;for 'guile-json'
  7740. (with-extensions (list guile-json)
  7741. (gexp->derivation "something-with-json"
  7742. #~(begin
  7743. (use-modules (json))
  7744. @dots{})))
  7745. @end lisp
  7746. The syntactic form to construct gexps is summarized below.
  7747. @deffn {Scheme Syntax} #~@var{exp}
  7748. @deffnx {Scheme Syntax} (gexp @var{exp})
  7749. Return a G-expression containing @var{exp}. @var{exp} may contain one
  7750. or more of the following forms:
  7751. @table @code
  7752. @item #$@var{obj}
  7753. @itemx (ungexp @var{obj})
  7754. Introduce a reference to @var{obj}. @var{obj} may have one of the
  7755. supported types, for example a package or a
  7756. derivation, in which case the @code{ungexp} form is replaced by its
  7757. output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
  7758. If @var{obj} is a list, it is traversed and references to supported
  7759. objects are substituted similarly.
  7760. If @var{obj} is another gexp, its contents are inserted and its
  7761. dependencies are added to those of the containing gexp.
  7762. If @var{obj} is another kind of object, it is inserted as is.
  7763. @item #$@var{obj}:@var{output}
  7764. @itemx (ungexp @var{obj} @var{output})
  7765. This is like the form above, but referring explicitly to the
  7766. @var{output} of @var{obj}---this is useful when @var{obj} produces
  7767. multiple outputs (@pxref{Packages with Multiple Outputs}).
  7768. @item #+@var{obj}
  7769. @itemx #+@var{obj}:output
  7770. @itemx (ungexp-native @var{obj})
  7771. @itemx (ungexp-native @var{obj} @var{output})
  7772. Same as @code{ungexp}, but produces a reference to the @emph{native}
  7773. build of @var{obj} when used in a cross compilation context.
  7774. @item #$output[:@var{output}]
  7775. @itemx (ungexp output [@var{output}])
  7776. Insert a reference to derivation output @var{output}, or to the main
  7777. output when @var{output} is omitted.
  7778. This only makes sense for gexps passed to @code{gexp->derivation}.
  7779. @item #$@@@var{lst}
  7780. @itemx (ungexp-splicing @var{lst})
  7781. Like the above, but splices the contents of @var{lst} inside the
  7782. containing list.
  7783. @item #+@@@var{lst}
  7784. @itemx (ungexp-native-splicing @var{lst})
  7785. Like the above, but refers to native builds of the objects listed in
  7786. @var{lst}.
  7787. @end table
  7788. G-expressions created by @code{gexp} or @code{#~} are run-time objects
  7789. of the @code{gexp?} type (see below).
  7790. @end deffn
  7791. @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
  7792. Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
  7793. in their execution environment.
  7794. Each item in @var{modules} can be the name of a module, such as
  7795. @code{(guix build utils)}, or it can be a module name, followed by an
  7796. arrow, followed by a file-like object:
  7797. @lisp
  7798. `((guix build utils)
  7799. (guix gcrypt)
  7800. ((guix config) => ,(scheme-file "config.scm"
  7801. #~(define-module @dots{}))))
  7802. @end lisp
  7803. @noindent
  7804. In the example above, the first two modules are taken from the search
  7805. path, and the last one is created from the given file-like object.
  7806. This form has @emph{lexical} scope: it has an effect on the gexps
  7807. directly defined in @var{body}@dots{}, but not on those defined, say, in
  7808. procedures called from @var{body}@dots{}.
  7809. @end deffn
  7810. @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
  7811. Mark the gexps defined in @var{body}@dots{} as requiring
  7812. @var{extensions} in their build and execution environment.
  7813. @var{extensions} is typically a list of package objects such as those
  7814. defined in the @code{(gnu packages guile)} module.
  7815. Concretely, the packages listed in @var{extensions} are added to the
  7816. load path while compiling imported modules in @var{body}@dots{}; they
  7817. are also added to the load path of the gexp returned by
  7818. @var{body}@dots{}.
  7819. @end deffn
  7820. @deffn {Scheme Procedure} gexp? @var{obj}
  7821. Return @code{#t} if @var{obj} is a G-expression.
  7822. @end deffn
  7823. G-expressions are meant to be written to disk, either as code building
  7824. some derivation, or as plain files in the store. The monadic procedures
  7825. below allow you to do that (@pxref{The Store Monad}, for more
  7826. information about monads).
  7827. @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
  7828. [#:system (%current-system)] [#:target #f] [#:graft? #t] @
  7829. [#:hash #f] [#:hash-algo #f] @
  7830. [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
  7831. [#:module-path @code{%load-path}] @
  7832. [#:effective-version "2.2"] @
  7833. [#:references-graphs #f] [#:allowed-references #f] @
  7834. [#:disallowed-references #f] @
  7835. [#:leaked-env-vars #f] @
  7836. [#:script-name (string-append @var{name} "-builder")] @
  7837. [#:deprecation-warnings #f] @
  7838. [#:local-build? #f] [#:substitutable? #t] @
  7839. [#:properties '()] [#:guile-for-build #f]
  7840. Return a derivation @var{name} that runs @var{exp} (a gexp) with
  7841. @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
  7842. stored in a file called @var{script-name}. When @var{target} is true,
  7843. it is used as the cross-compilation target triplet for packages referred
  7844. to by @var{exp}.
  7845. @var{modules} is deprecated in favor of @code{with-imported-modules}.
  7846. Its meaning is to
  7847. make @var{modules} available in the evaluation context of @var{exp};
  7848. @var{modules} is a list of names of Guile modules searched in
  7849. @var{module-path} to be copied in the store, compiled, and made available in
  7850. the load path during the execution of @var{exp}---e.g., @code{((guix
  7851. build utils) (guix build gnu-build-system))}.
  7852. @var{effective-version} determines the string to use when adding extensions of
  7853. @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
  7854. @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
  7855. applicable.
  7856. When @var{references-graphs} is true, it must be a list of tuples of one of the
  7857. following forms:
  7858. @example
  7859. (@var{file-name} @var{package})
  7860. (@var{file-name} @var{package} @var{output})
  7861. (@var{file-name} @var{derivation})
  7862. (@var{file-name} @var{derivation} @var{output})
  7863. (@var{file-name} @var{store-item})
  7864. @end example
  7865. The right-hand-side of each element of @var{references-graphs} is automatically made
  7866. an input of the build process of @var{exp}. In the build environment, each
  7867. @var{file-name} contains the reference graph of the corresponding item, in a simple
  7868. text format.
  7869. @var{allowed-references} must be either @code{#f} or a list of output names and packages.
  7870. In the latter case, the list denotes store items that the result is allowed to
  7871. refer to. Any reference to another store item will lead to a build error.
  7872. Similarly for @var{disallowed-references}, which can list items that must not be
  7873. referenced by the outputs.
  7874. @var{deprecation-warnings} determines whether to show deprecation warnings while
  7875. compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
  7876. The other arguments are as for @code{derivation} (@pxref{Derivations}).
  7877. @end deffn
  7878. @cindex file-like objects
  7879. The @code{local-file}, @code{plain-file}, @code{computed-file},
  7880. @code{program-file}, and @code{scheme-file} procedures below return
  7881. @dfn{file-like objects}. That is, when unquoted in a G-expression,
  7882. these objects lead to a file in the store. Consider this G-expression:
  7883. @lisp
  7884. #~(system* #$(file-append glibc "/sbin/nscd") "-f"
  7885. #$(local-file "/tmp/my-nscd.conf"))
  7886. @end lisp
  7887. The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
  7888. to the store. Once expanded, for instance @i{via}
  7889. @code{gexp->derivation}, the G-expression refers to that copy under
  7890. @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
  7891. does not have any effect on what the G-expression does.
  7892. @code{plain-file} can be used similarly; it differs in that the file
  7893. content is directly passed as a string.
  7894. @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
  7895. [#:recursive? #f] [#:select? (const #t)]
  7896. Return an object representing local file @var{file} to add to the store;
  7897. this object can be used in a gexp. If @var{file} is a literal string
  7898. denoting a relative file name, it is looked up relative to the source
  7899. file where it appears; if @var{file} is not a literal string, it is
  7900. looked up relative to the current working directory at run time.
  7901. @var{file} will be added to the store under @var{name}--by default the
  7902. base name of @var{file}.
  7903. When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
  7904. designates a flat file and @var{recursive?} is true, its contents are added, and its
  7905. permission bits are kept.
  7906. When @var{recursive?} is true, call @code{(@var{select?} @var{file}
  7907. @var{stat})} for each directory entry, where @var{file} is the entry's
  7908. absolute file name and @var{stat} is the result of @code{lstat}; exclude
  7909. entries for which @var{select?} does not return true.
  7910. This is the declarative counterpart of the @code{interned-file} monadic
  7911. procedure (@pxref{The Store Monad, @code{interned-file}}).
  7912. @end deffn
  7913. @deffn {Scheme Procedure} plain-file @var{name} @var{content}
  7914. Return an object representing a text file called @var{name} with the given
  7915. @var{content} (a string or a bytevector) to be added to the store.
  7916. This is the declarative counterpart of @code{text-file}.
  7917. @end deffn
  7918. @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
  7919. [#:local-build? #t]
  7920. [#:options '()]
  7921. Return an object representing the store item @var{name}, a file or
  7922. directory computed by @var{gexp}. When @var{local-build?} is true (the
  7923. default), the derivation is built locally. @var{options} is a list of
  7924. additional arguments to pass to @code{gexp->derivation}.
  7925. This is the declarative counterpart of @code{gexp->derivation}.
  7926. @end deffn
  7927. @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
  7928. [#:guile (default-guile)] [#:module-path %load-path] @
  7929. [#:system (%current-system)] [#:target #f]
  7930. Return an executable script @var{name} that runs @var{exp} using
  7931. @var{guile}, with @var{exp}'s imported modules in its search path.
  7932. Look up @var{exp}'s modules in @var{module-path}.
  7933. The example below builds a script that simply invokes the @command{ls}
  7934. command:
  7935. @lisp
  7936. (use-modules (guix gexp) (gnu packages base))
  7937. (gexp->script "list-files"
  7938. #~(execl #$(file-append coreutils "/bin/ls")
  7939. "ls"))
  7940. @end lisp
  7941. When ``running'' it through the store (@pxref{The Store Monad,
  7942. @code{run-with-store}}), we obtain a derivation that produces an
  7943. executable file @file{/gnu/store/@dots{}-list-files} along these lines:
  7944. @example
  7945. #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
  7946. !#
  7947. (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
  7948. @end example
  7949. @end deffn
  7950. @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
  7951. [#:guile #f] [#:module-path %load-path]
  7952. Return an object representing the executable store item @var{name} that
  7953. runs @var{gexp}. @var{guile} is the Guile package used to execute that
  7954. script. Imported modules of @var{gexp} are looked up in @var{module-path}.
  7955. This is the declarative counterpart of @code{gexp->script}.
  7956. @end deffn
  7957. @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
  7958. [#:set-load-path? #t] [#:module-path %load-path] @
  7959. [#:splice? #f] @
  7960. [#:guile (default-guile)]
  7961. Return a derivation that builds a file @var{name} containing @var{exp}.
  7962. When @var{splice?} is true, @var{exp} is considered to be a list of
  7963. expressions that will be spliced in the resulting file.
  7964. When @var{set-load-path?} is true, emit code in the resulting file to
  7965. set @code{%load-path} and @code{%load-compiled-path} to honor
  7966. @var{exp}'s imported modules. Look up @var{exp}'s modules in
  7967. @var{module-path}.
  7968. The resulting file holds references to all the dependencies of @var{exp}
  7969. or a subset thereof.
  7970. @end deffn
  7971. @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
  7972. [#:splice? #f] [#:set-load-path? #t]
  7973. Return an object representing the Scheme file @var{name} that contains
  7974. @var{exp}.
  7975. This is the declarative counterpart of @code{gexp->file}.
  7976. @end deffn
  7977. @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
  7978. Return as a monadic value a derivation that builds a text file
  7979. containing all of @var{text}. @var{text} may list, in addition to
  7980. strings, objects of any type that can be used in a gexp: packages,
  7981. derivations, local file objects, etc. The resulting store file holds
  7982. references to all these.
  7983. This variant should be preferred over @code{text-file} anytime the file
  7984. to create will reference items from the store. This is typically the
  7985. case when building a configuration file that embeds store file names,
  7986. like this:
  7987. @lisp
  7988. (define (profile.sh)
  7989. ;; Return the name of a shell script in the store that
  7990. ;; initializes the 'PATH' environment variable.
  7991. (text-file* "profile.sh"
  7992. "export PATH=" coreutils "/bin:"
  7993. grep "/bin:" sed "/bin\n"))
  7994. @end lisp
  7995. In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
  7996. will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
  7997. preventing them from being garbage-collected during its lifetime.
  7998. @end deffn
  7999. @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
  8000. Return an object representing store file @var{name} containing
  8001. @var{text}. @var{text} is a sequence of strings and file-like objects,
  8002. as in:
  8003. @lisp
  8004. (mixed-text-file "profile"
  8005. "export PATH=" coreutils "/bin:" grep "/bin")
  8006. @end lisp
  8007. This is the declarative counterpart of @code{text-file*}.
  8008. @end deffn
  8009. @deffn {Scheme Procedure} file-union @var{name} @var{files}
  8010. Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
  8011. Each item in @var{files} must be a two-element list where the first element is the
  8012. file name to use in the new directory, and the second element is a gexp
  8013. denoting the target file. Here's an example:
  8014. @lisp
  8015. (file-union "etc"
  8016. `(("hosts" ,(plain-file "hosts"
  8017. "127.0.0.1 localhost"))
  8018. ("bashrc" ,(plain-file "bashrc"
  8019. "alias ls='ls --color=auto'"))))
  8020. @end lisp
  8021. This yields an @code{etc} directory containing these two files.
  8022. @end deffn
  8023. @deffn {Scheme Procedure} directory-union @var{name} @var{things}
  8024. Return a directory that is the union of @var{things}, where @var{things} is a list of
  8025. file-like objects denoting directories. For example:
  8026. @lisp
  8027. (directory-union "guile+emacs" (list guile emacs))
  8028. @end lisp
  8029. yields a directory that is the union of the @code{guile} and @code{emacs} packages.
  8030. @end deffn
  8031. @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
  8032. Return a file-like object that expands to the concatenation of @var{obj}
  8033. and @var{suffix}, where @var{obj} is a lowerable object and each
  8034. @var{suffix} is a string.
  8035. As an example, consider this gexp:
  8036. @lisp
  8037. (gexp->script "run-uname"
  8038. #~(system* #$(file-append coreutils
  8039. "/bin/uname")))
  8040. @end lisp
  8041. The same effect could be achieved with:
  8042. @lisp
  8043. (gexp->script "run-uname"
  8044. #~(system* (string-append #$coreutils
  8045. "/bin/uname")))
  8046. @end lisp
  8047. There is one difference though: in the @code{file-append} case, the
  8048. resulting script contains the absolute file name as a string, whereas in
  8049. the second case, the resulting script contains a @code{(string-append
  8050. @dots{})} expression to construct the file name @emph{at run time}.
  8051. @end deffn
  8052. @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
  8053. @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
  8054. Bind @var{system} to the currently targeted system---e.g.,
  8055. @code{"x86_64-linux"}---within @var{body}.
  8056. In the second case, additionally bind @var{target} to the current
  8057. cross-compilation target---a GNU triplet such as
  8058. @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
  8059. cross-compiling.
  8060. @code{let-system} is useful in the occasional case where the object
  8061. spliced into the gexp depends on the target system, as in this example:
  8062. @lisp
  8063. #~(system*
  8064. #+(let-system system
  8065. (cond ((string-prefix? "armhf-" system)
  8066. (file-append qemu "/bin/qemu-system-arm"))
  8067. ((string-prefix? "x86_64-" system)
  8068. (file-append qemu "/bin/qemu-system-x86_64"))
  8069. (else
  8070. (error "dunno!"))))
  8071. "-net" "user" #$image)
  8072. @end lisp
  8073. @end deffn
  8074. @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
  8075. This macro is similar to the @code{parameterize} form for
  8076. dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
  8077. Guile Reference Manual}). The key difference is that it takes effect
  8078. when the file-like object returned by @var{exp} is lowered to a
  8079. derivation or store item.
  8080. A typical use of @code{with-parameters} is to force the system in effect
  8081. for a given object:
  8082. @lisp
  8083. (with-parameters ((%current-system "i686-linux"))
  8084. coreutils)
  8085. @end lisp
  8086. The example above returns an object that corresponds to the i686 build
  8087. of Coreutils, regardless of the current value of @code{%current-system}.
  8088. @end deffn
  8089. Of course, in addition to gexps embedded in ``host'' code, there are
  8090. also modules containing build tools. To make it clear that they are
  8091. meant to be used in the build stratum, these modules are kept in the
  8092. @code{(guix build @dots{})} name space.
  8093. @cindex lowering, of high-level objects in gexps
  8094. Internally, high-level objects are @dfn{lowered}, using their compiler,
  8095. to either derivations or store items. For instance, lowering a package
  8096. yields a derivation, and lowering a @code{plain-file} yields a store
  8097. item. This is achieved using the @code{lower-object} monadic procedure.
  8098. @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
  8099. [#:target #f]
  8100. Return as a value in @code{%store-monad} the derivation or store item
  8101. corresponding to @var{obj} for @var{system}, cross-compiling for
  8102. @var{target} if @var{target} is true. @var{obj} must be an object that
  8103. has an associated gexp compiler, such as a @code{<package>}.
  8104. @end deffn
  8105. @node Invoking guix repl
  8106. @section Invoking @command{guix repl}
  8107. @cindex REPL, read-eval-print loop, script
  8108. The @command{guix repl} command makes it easier to program Guix in Guile
  8109. by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
  8110. programming (@pxref{Using Guile Interactively,,, guile,
  8111. GNU Guile Reference Manual}), or by running Guile scripts
  8112. (@pxref{Running Guile Scripts,,, guile,
  8113. GNU Guile Reference Manual}).
  8114. Compared to just launching the @command{guile}
  8115. command, @command{guix repl} guarantees that all the Guix modules and all its
  8116. dependencies are available in the search path.
  8117. The general syntax is:
  8118. @example
  8119. guix repl @var{options} [@var{file} @var{args}]
  8120. @end example
  8121. When a @var{file} argument is provided, @var{file} is
  8122. executed as a Guile scripts:
  8123. @example
  8124. guix repl my-script.scm
  8125. @end example
  8126. To pass arguments to the script, use @code{--} to prevent them from
  8127. being interpreted as arguments to @command{guix repl} itself:
  8128. @example
  8129. guix repl -- my-script.scm --input=foo.txt
  8130. @end example
  8131. To make a script executable directly from the shell, using the guix
  8132. executable that is on the user's search path, add the following two
  8133. lines at the top of the script:
  8134. @example
  8135. @code{#!/usr/bin/env -S guix repl --}
  8136. @code{!#}
  8137. @end example
  8138. Without a file name argument, a Guile REPL is started:
  8139. @example
  8140. $ guix repl
  8141. scheme@@(guile-user)> ,use (gnu packages base)
  8142. scheme@@(guile-user)> coreutils
  8143. $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
  8144. @end example
  8145. @cindex inferiors
  8146. In addition, @command{guix repl} implements a simple machine-readable REPL
  8147. protocol for use by @code{(guix inferior)}, a facility to interact with
  8148. @dfn{inferiors}, separate processes running a potentially different revision
  8149. of Guix.
  8150. The available options are as follows:
  8151. @table @code
  8152. @item --type=@var{type}
  8153. @itemx -t @var{type}
  8154. Start a REPL of the given @var{TYPE}, which can be one of the following:
  8155. @table @code
  8156. @item guile
  8157. This is default, and it spawns a standard full-featured Guile REPL.
  8158. @item machine
  8159. Spawn a REPL that uses the machine-readable protocol. This is the protocol
  8160. that the @code{(guix inferior)} module speaks.
  8161. @end table
  8162. @item --listen=@var{endpoint}
  8163. By default, @command{guix repl} reads from standard input and writes to
  8164. standard output. When this option is passed, it will instead listen for
  8165. connections on @var{endpoint}. Here are examples of valid options:
  8166. @table @code
  8167. @item --listen=tcp:37146
  8168. Accept connections on localhost on port 37146.
  8169. @item --listen=unix:/tmp/socket
  8170. Accept connections on the Unix-domain socket @file{/tmp/socket}.
  8171. @end table
  8172. @item --load-path=@var{directory}
  8173. @itemx -L @var{directory}
  8174. Add @var{directory} to the front of the package module search path
  8175. (@pxref{Package Modules}).
  8176. This allows users to define their own packages and make them visible to
  8177. the script or REPL.
  8178. @item -q
  8179. Inhibit loading of the @file{~/.guile} file. By default, that
  8180. configuration file is loaded when spawning a @code{guile} REPL.
  8181. @end table
  8182. @c *********************************************************************
  8183. @node Utilities
  8184. @chapter Utilities
  8185. This section describes Guix command-line utilities. Some of them are
  8186. primarily targeted at developers and users who write new package
  8187. definitions, while others are more generally useful. They complement
  8188. the Scheme programming interface of Guix in a convenient way.
  8189. @menu
  8190. * Invoking guix build:: Building packages from the command line.
  8191. * Invoking guix edit:: Editing package definitions.
  8192. * Invoking guix download:: Downloading a file and printing its hash.
  8193. * Invoking guix hash:: Computing the cryptographic hash of a file.
  8194. * Invoking guix import:: Importing package definitions.
  8195. * Invoking guix refresh:: Updating package definitions.
  8196. * Invoking guix lint:: Finding errors in package definitions.
  8197. * Invoking guix size:: Profiling disk usage.
  8198. * Invoking guix graph:: Visualizing the graph of packages.
  8199. * Invoking guix publish:: Sharing substitutes.
  8200. * Invoking guix challenge:: Challenging substitute servers.
  8201. * Invoking guix copy:: Copying to and from a remote store.
  8202. * Invoking guix container:: Process isolation.
  8203. * Invoking guix weather:: Assessing substitute availability.
  8204. * Invoking guix processes:: Listing client processes.
  8205. @end menu
  8206. @node Invoking guix build
  8207. @section Invoking @command{guix build}
  8208. @cindex package building
  8209. @cindex @command{guix build}
  8210. The @command{guix build} command builds packages or derivations and
  8211. their dependencies, and prints the resulting store paths. Note that it
  8212. does not modify the user's profile---this is the job of the
  8213. @command{guix package} command (@pxref{Invoking guix package}). Thus,
  8214. it is mainly useful for distribution developers.
  8215. The general syntax is:
  8216. @example
  8217. guix build @var{options} @var{package-or-derivation}@dots{}
  8218. @end example
  8219. As an example, the following command builds the latest versions of Emacs
  8220. and of Guile, displays their build logs, and finally displays the
  8221. resulting directories:
  8222. @example
  8223. guix build emacs guile
  8224. @end example
  8225. Similarly, the following command builds all the available packages:
  8226. @example
  8227. guix build --quiet --keep-going \
  8228. `guix package -A | cut -f1,2 --output-delimiter=@@`
  8229. @end example
  8230. @var{package-or-derivation} may be either the name of a package found in
  8231. the software distribution such as @code{coreutils} or
  8232. @code{coreutils@@8.20}, or a derivation such as
  8233. @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
  8234. package with the corresponding name (and optionally version) is searched
  8235. for among the GNU distribution modules (@pxref{Package Modules}).
  8236. Alternatively, the @option{--expression} option may be used to specify a
  8237. Scheme expression that evaluates to a package; this is useful when
  8238. disambiguating among several same-named packages or package variants is
  8239. needed.
  8240. There may be zero or more @var{options}. The available options are
  8241. described in the subsections below.
  8242. @menu
  8243. * Common Build Options:: Build options for most commands.
  8244. * Package Transformation Options:: Creating variants of packages.
  8245. * Additional Build Options:: Options specific to 'guix build'.
  8246. * Debugging Build Failures:: Real life packaging experience.
  8247. @end menu
  8248. @node Common Build Options
  8249. @subsection Common Build Options
  8250. A number of options that control the build process are common to
  8251. @command{guix build} and other commands that can spawn builds, such as
  8252. @command{guix package} or @command{guix archive}. These are the
  8253. following:
  8254. @table @code
  8255. @item --load-path=@var{directory}
  8256. @itemx -L @var{directory}
  8257. Add @var{directory} to the front of the package module search path
  8258. (@pxref{Package Modules}).
  8259. This allows users to define their own packages and make them visible to
  8260. the command-line tools.
  8261. @item --keep-failed
  8262. @itemx -K
  8263. Keep the build tree of failed builds. Thus, if a build fails, its build
  8264. tree is kept under @file{/tmp}, in a directory whose name is shown at
  8265. the end of the build log. This is useful when debugging build issues.
  8266. @xref{Debugging Build Failures}, for tips and tricks on how to debug
  8267. build issues.
  8268. This option implies @option{--no-offload}, and it has no effect when
  8269. connecting to a remote daemon with a @code{guix://} URI (@pxref{The
  8270. Store, the @env{GUIX_DAEMON_SOCKET} variable}).
  8271. @item --keep-going
  8272. @itemx -k
  8273. Keep going when some of the derivations fail to build; return only once
  8274. all the builds have either completed or failed.
  8275. The default behavior is to stop as soon as one of the specified
  8276. derivations has failed.
  8277. @item --dry-run
  8278. @itemx -n
  8279. Do not build the derivations.
  8280. @anchor{fallback-option}
  8281. @item --fallback
  8282. When substituting a pre-built binary fails, fall back to building
  8283. packages locally (@pxref{Substitution Failure}).
  8284. @item --substitute-urls=@var{urls}
  8285. @anchor{client-substitute-urls}
  8286. Consider @var{urls} the whitespace-separated list of substitute source
  8287. URLs, overriding the default list of URLs of @command{guix-daemon}
  8288. (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
  8289. This means that substitutes may be downloaded from @var{urls}, provided
  8290. they are signed by a key authorized by the system administrator
  8291. (@pxref{Substitutes}).
  8292. When @var{urls} is the empty string, substitutes are effectively
  8293. disabled.
  8294. @item --no-substitutes
  8295. Do not use substitutes for build products. That is, always build things
  8296. locally instead of allowing downloads of pre-built binaries
  8297. (@pxref{Substitutes}).
  8298. @item --no-grafts
  8299. Do not ``graft'' packages. In practice, this means that package updates
  8300. available as grafts are not applied. @xref{Security Updates}, for more
  8301. information on grafts.
  8302. @item --rounds=@var{n}
  8303. Build each derivation @var{n} times in a row, and raise an error if
  8304. consecutive build results are not bit-for-bit identical.
  8305. This is a useful way to detect non-deterministic builds processes.
  8306. Non-deterministic build processes are a problem because they make it
  8307. practically impossible for users to @emph{verify} whether third-party
  8308. binaries are genuine. @xref{Invoking guix challenge}, for more.
  8309. When used in conjunction with @option{--keep-failed}, the differing
  8310. output is kept in the store, under @file{/gnu/store/@dots{}-check}.
  8311. This makes it easy to look for differences between the two results.
  8312. @item --no-offload
  8313. Do not use offload builds to other machines (@pxref{Daemon Offload
  8314. Setup}). That is, always build things locally instead of offloading
  8315. builds to remote machines.
  8316. @item --max-silent-time=@var{seconds}
  8317. When the build or substitution process remains silent for more than
  8318. @var{seconds}, terminate it and report a build failure.
  8319. By default, the daemon's setting is honored (@pxref{Invoking
  8320. guix-daemon, @option{--max-silent-time}}).
  8321. @item --timeout=@var{seconds}
  8322. Likewise, when the build or substitution process lasts for more than
  8323. @var{seconds}, terminate it and report a build failure.
  8324. By default, the daemon's setting is honored (@pxref{Invoking
  8325. guix-daemon, @option{--timeout}}).
  8326. @c Note: This option is actually not part of %standard-build-options but
  8327. @c most programs honor it.
  8328. @cindex verbosity, of the command-line tools
  8329. @cindex build logs, verbosity
  8330. @item -v @var{level}
  8331. @itemx --verbosity=@var{level}
  8332. Use the given verbosity @var{level}, an integer. Choosing 0 means that no
  8333. output is produced, 1 is for quiet output, and 2 shows all the build log
  8334. output on standard error.
  8335. @item --cores=@var{n}
  8336. @itemx -c @var{n}
  8337. Allow the use of up to @var{n} CPU cores for the build. The special
  8338. value @code{0} means to use as many CPU cores as available.
  8339. @item --max-jobs=@var{n}
  8340. @itemx -M @var{n}
  8341. Allow at most @var{n} build jobs in parallel. @xref{Invoking
  8342. guix-daemon, @option{--max-jobs}}, for details about this option and the
  8343. equivalent @command{guix-daemon} option.
  8344. @item --debug=@var{level}
  8345. Produce debugging output coming from the build daemon. @var{level} must be an
  8346. integer between 0 and 5; higher means more verbose output. Setting a level of
  8347. 4 or more may be helpful when debugging setup issues with the build daemon.
  8348. @end table
  8349. Behind the scenes, @command{guix build} is essentially an interface to
  8350. the @code{package-derivation} procedure of the @code{(guix packages)}
  8351. module, and to the @code{build-derivations} procedure of the @code{(guix
  8352. derivations)} module.
  8353. In addition to options explicitly passed on the command line,
  8354. @command{guix build} and other @command{guix} commands that support
  8355. building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
  8356. @defvr {Environment Variable} GUIX_BUILD_OPTIONS
  8357. Users can define this variable to a list of command line options that
  8358. will automatically be used by @command{guix build} and other
  8359. @command{guix} commands that can perform builds, as in the example
  8360. below:
  8361. @example
  8362. $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
  8363. @end example
  8364. These options are parsed independently, and the result is appended to
  8365. the parsed command-line options.
  8366. @end defvr
  8367. @node Package Transformation Options
  8368. @subsection Package Transformation Options
  8369. @cindex package variants
  8370. Another set of command-line options supported by @command{guix build}
  8371. and also @command{guix package} are @dfn{package transformation
  8372. options}. These are options that make it possible to define @dfn{package
  8373. variants}---for instance, packages built from different source code.
  8374. This is a convenient way to create customized packages on the fly
  8375. without having to type in the definitions of package variants
  8376. (@pxref{Defining Packages}).
  8377. Package transformation options are preserved across upgrades:
  8378. @command{guix upgrade} attempts to apply transformation options
  8379. initially used when creating the profile to the upgraded packages.
  8380. The available options are listed below. Most commands support them and
  8381. also support a @option{--help-transform} option that lists all the
  8382. available options and a synopsis (these options are not shown in the
  8383. @option{--help} output for brevity).
  8384. @table @code
  8385. @item --with-source=@var{source}
  8386. @itemx --with-source=@var{package}=@var{source}
  8387. @itemx --with-source=@var{package}@@@var{version}=@var{source}
  8388. Use @var{source} as the source of @var{package}, and @var{version} as
  8389. its version number.
  8390. @var{source} must be a file name or a URL, as for @command{guix
  8391. download} (@pxref{Invoking guix download}).
  8392. When @var{package} is omitted,
  8393. it is taken to be the package name specified on the
  8394. command line that matches the base of @var{source}---e.g.,
  8395. if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
  8396. package is @code{guile}.
  8397. Likewise, when @var{version} is omitted, the version string is inferred from
  8398. @var{source}; in the previous example, it is @code{2.0.10}.
  8399. This option allows users to try out versions of packages other than the
  8400. one provided by the distribution. The example below downloads
  8401. @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
  8402. the @code{ed} package:
  8403. @example
  8404. guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
  8405. @end example
  8406. As a developer, @option{--with-source} makes it easy to test release
  8407. candidates:
  8408. @example
  8409. guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
  8410. @end example
  8411. @dots{} or to build from a checkout in a pristine environment:
  8412. @example
  8413. $ git clone git://git.sv.gnu.org/guix.git
  8414. $ guix build guix --with-source=guix@@1.0=./guix
  8415. @end example
  8416. @item --with-input=@var{package}=@var{replacement}
  8417. Replace dependency on @var{package} by a dependency on
  8418. @var{replacement}. @var{package} must be a package name, and
  8419. @var{replacement} must be a package specification such as @code{guile}
  8420. or @code{guile@@1.8}.
  8421. For instance, the following command builds Guix, but replaces its
  8422. dependency on the current stable version of Guile with a dependency on
  8423. the legacy version of Guile, @code{guile@@2.0}:
  8424. @example
  8425. guix build --with-input=guile=guile@@2.0 guix
  8426. @end example
  8427. This is a recursive, deep replacement. So in this example, both
  8428. @code{guix} and its dependency @code{guile-json} (which also depends on
  8429. @code{guile}) get rebuilt against @code{guile@@2.0}.
  8430. This is implemented using the @code{package-input-rewriting} Scheme
  8431. procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
  8432. @item --with-graft=@var{package}=@var{replacement}
  8433. This is similar to @option{--with-input} but with an important difference:
  8434. instead of rebuilding the whole dependency chain, @var{replacement} is
  8435. built and then @dfn{grafted} onto the binaries that were initially
  8436. referring to @var{package}. @xref{Security Updates}, for more
  8437. information on grafts.
  8438. For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
  8439. and all its dependencies, replacing references to the version of GnuTLS
  8440. they currently refer to:
  8441. @example
  8442. guix build --with-graft=gnutls=gnutls@@3.5.4 wget
  8443. @end example
  8444. This has the advantage of being much faster than rebuilding everything.
  8445. But there is a caveat: it works if and only if @var{package} and
  8446. @var{replacement} are strictly compatible---for example, if they provide
  8447. a library, the application binary interface (ABI) of those libraries
  8448. must be compatible. If @var{replacement} is somehow incompatible with
  8449. @var{package}, then the resulting package may be unusable. Use with
  8450. care!
  8451. @cindex debugging info, rebuilding
  8452. @item --with-debug-info=@var{package}
  8453. Build @var{package} in a way that preserves its debugging info and graft
  8454. it onto packages that depend on it. This is useful if @var{package}
  8455. does not already provide debugging info as a @code{debug} output
  8456. (@pxref{Installing Debugging Files}).
  8457. For example, suppose you're experiencing a crash in Inkscape and would
  8458. like to see what's up in GLib, a library deep down in Inkscape's
  8459. dependency graph. GLib lacks a @code{debug} output, so debugging is
  8460. tough. Fortunately, you rebuild GLib with debugging info and tack it on
  8461. Inkscape:
  8462. @example
  8463. guix install inkscape --with-debug-info=glib
  8464. @end example
  8465. Only GLib needs to be recompiled so this takes a reasonable amount of
  8466. time. @xref{Installing Debugging Files}, for more info.
  8467. @quotation Note
  8468. Under the hood, this option works by passing the @samp{#:strip-binaries?
  8469. #f} to the build system of the package of interest (@pxref{Build
  8470. Systems}). Most build systems support that option but some do not. In
  8471. that case, an error is raised.
  8472. Likewise, if a C/C++ package is built without @code{-g} (which is rarely
  8473. the case), debugging info will remain unavailable even when
  8474. @code{#:strip-binaries?} is false.
  8475. @end quotation
  8476. @cindex tool chain, changing the build tool chain of a package
  8477. @item --with-c-toolchain=@var{package}=@var{toolchain}
  8478. This option changes the compilation of @var{package} and everything that
  8479. depends on it so that they get built with @var{toolchain} instead of the
  8480. default GNU tool chain for C/C++.
  8481. Consider this example:
  8482. @example
  8483. guix build octave-cli \
  8484. --with-c-toolchain=fftw=gcc-toolchain@@10 \
  8485. --with-c-toolchain=fftwf=gcc-toolchain@@10
  8486. @end example
  8487. The command above builds a variant of the @code{fftw} and @code{fftwf}
  8488. packages using version 10 of @code{gcc-toolchain} instead of the default
  8489. tool chain, and then builds a variant of the GNU@tie{}Octave
  8490. command-line interface using them. GNU@tie{}Octave itself is also built
  8491. with @code{gcc-toolchain@@10}.
  8492. This other example builds the Hardware Locality (@code{hwloc}) library
  8493. and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
  8494. compiler:
  8495. @example
  8496. guix build --with-c-toolchain=hwloc=clang-toolchain \
  8497. intel-mpi-benchmarks
  8498. @end example
  8499. @quotation Note
  8500. There can be application binary interface (ABI) incompatibilities among
  8501. tool chains. This is particularly true of the C++ standard library and
  8502. run-time support libraries such as that of OpenMP@. By rebuilding all
  8503. dependents with the same tool chain, @option{--with-c-toolchain} minimizes
  8504. the risks of incompatibility but cannot entirely eliminate them. Choose
  8505. @var{package} wisely.
  8506. @end quotation
  8507. @item --with-git-url=@var{package}=@var{url}
  8508. @cindex Git, using the latest commit
  8509. @cindex latest commit, building
  8510. Build @var{package} from the latest commit of the @code{master} branch of the
  8511. Git repository at @var{url}. Git sub-modules of the repository are fetched,
  8512. recursively.
  8513. For example, the following command builds the NumPy Python library against the
  8514. latest commit of the master branch of Python itself:
  8515. @example
  8516. guix build python-numpy \
  8517. --with-git-url=python=https://github.com/python/cpython
  8518. @end example
  8519. This option can also be combined with @option{--with-branch} or
  8520. @option{--with-commit} (see below).
  8521. @cindex continuous integration
  8522. Obviously, since it uses the latest commit of the given branch, the result of
  8523. such a command varies over time. Nevertheless it is a convenient way to
  8524. rebuild entire software stacks against the latest commit of one or more
  8525. packages. This is particularly useful in the context of continuous
  8526. integration (CI).
  8527. Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
  8528. consecutive accesses to the same repository. You may want to clean it up once
  8529. in a while to save disk space.
  8530. @item --with-branch=@var{package}=@var{branch}
  8531. Build @var{package} from the latest commit of @var{branch}. If the
  8532. @code{source} field of @var{package} is an origin with the @code{git-fetch}
  8533. method (@pxref{origin Reference}) or a @code{git-checkout} object, the
  8534. repository URL is taken from that @code{source}. Otherwise you have to use
  8535. @option{--with-git-url} to specify the URL of the Git repository.
  8536. For instance, the following command builds @code{guile-sqlite3} from the
  8537. latest commit of its @code{master} branch, and then builds @code{guix} (which
  8538. depends on it) and @code{cuirass} (which depends on @code{guix}) against this
  8539. specific @code{guile-sqlite3} build:
  8540. @example
  8541. guix build --with-branch=guile-sqlite3=master cuirass
  8542. @end example
  8543. @item --with-commit=@var{package}=@var{commit}
  8544. This is similar to @option{--with-branch}, except that it builds from
  8545. @var{commit} rather than the tip of a branch. @var{commit} must be a valid
  8546. Git commit SHA1 identifier or a tag.
  8547. @item --with-patch=@var{package}=@var{file}
  8548. Add @var{file} to the list of patches applied to @var{package}, where
  8549. @var{package} is a spec such as @code{python@@3.8} or @code{glibc}.
  8550. @var{file} must contain a patch; it is applied with the flags specified
  8551. in the @code{origin} of @var{package} (@pxref{origin Reference}), which
  8552. by default includes @code{-p1} (@pxref{patch Directories,,, diffutils,
  8553. Comparing and Merging Files}).
  8554. As an example, the command below rebuilds Coreutils with the GNU C
  8555. Library (glibc) patched with the given patch:
  8556. @example
  8557. guix build coreutils --with-patch=glibc=./glibc-frob.patch
  8558. @end example
  8559. In this example, glibc itself as well as everything that leads to
  8560. Coreutils in the dependency graph is rebuilt.
  8561. @cindex upstream, latest version
  8562. @item --with-latest=@var{package}
  8563. So you like living on the bleeding edge? This option is for you! It
  8564. replaces occurrences of @var{package} in the dependency graph with its
  8565. latest upstream version, as reported by @command{guix refresh}
  8566. (@pxref{Invoking guix refresh}).
  8567. It does so by determining the latest upstream release of @var{package}
  8568. (if possible), downloading it, and authenticating it @emph{if} it comes
  8569. with an OpenPGP signature.
  8570. As an example, the command below builds Guix against the latest version
  8571. of Guile-JSON:
  8572. @example
  8573. guix build guix --with-latest=guile-json
  8574. @end example
  8575. There are limitations. First, in cases where the tool cannot or does
  8576. not know how to authenticate source code, you are at risk of running
  8577. malicious code; a warning is emitted in this case. Second, this option
  8578. simply changes the source used in the existing package definitions,
  8579. which is not always sufficient: there might be additional dependencies
  8580. that need to be added, patches to apply, and more generally the quality
  8581. assurance work that Guix developers normally do will be missing.
  8582. You've been warned! In all the other cases, it's a snappy way to stay
  8583. on top. We encourage you to submit patches updating the actual package
  8584. definitions once you have successfully tested an upgrade
  8585. (@pxref{Contributing}).
  8586. @cindex test suite, skipping
  8587. @item --without-tests=@var{package}
  8588. Build @var{package} without running its tests. This can be useful in
  8589. situations where you want to skip the lengthy test suite of a
  8590. intermediate package, or if a package's test suite fails in a
  8591. non-deterministic fashion. It should be used with care because running
  8592. the test suite is a good way to ensure a package is working as intended.
  8593. Turning off tests leads to a different store item. Consequently, when
  8594. using this option, anything that depends on @var{package} must be
  8595. rebuilt, as in this example:
  8596. @example
  8597. guix install --without-tests=python python-notebook
  8598. @end example
  8599. The command above installs @code{python-notebook} on top of
  8600. @code{python} built without running its test suite. To do so, it also
  8601. rebuilds everything that depends on @code{python}, including
  8602. @code{python-notebook} itself.
  8603. Internally, @option{--without-tests} relies on changing the
  8604. @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
  8605. Systems}). Note that some packages use a customized @code{check} phase
  8606. that does not respect a @code{#:tests? #f} setting. Therefore,
  8607. @option{--without-tests} has no effect on these packages.
  8608. @end table
  8609. Wondering how to achieve the same effect using Scheme code, for example
  8610. in your manifest, or how to write your own package transformation?
  8611. @xref{Defining Package Variants}, for an overview of the programming
  8612. interfaces available.
  8613. @node Additional Build Options
  8614. @subsection Additional Build Options
  8615. The command-line options presented below are specific to @command{guix
  8616. build}.
  8617. @table @code
  8618. @item --quiet
  8619. @itemx -q
  8620. Build quietly, without displaying the build log; this is equivalent to
  8621. @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
  8622. (or similar) and can always be retrieved using the @option{--log-file} option.
  8623. @item --file=@var{file}
  8624. @itemx -f @var{file}
  8625. Build the package, derivation, or other file-like object that the code within
  8626. @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
  8627. As an example, @var{file} might contain a package definition like this
  8628. (@pxref{Defining Packages}):
  8629. @lisp
  8630. @include package-hello.scm
  8631. @end lisp
  8632. The @var{file} may also contain a JSON representation of one or more
  8633. package definitions. Running @code{guix build -f} on @file{hello.json}
  8634. with the following contents would result in building the packages
  8635. @code{myhello} and @code{greeter}:
  8636. @example
  8637. @verbatiminclude package-hello.json
  8638. @end example
  8639. @item --manifest=@var{manifest}
  8640. @itemx -m @var{manifest}
  8641. Build all packages listed in the given @var{manifest}
  8642. (@pxref{profile-manifest, @option{--manifest}}).
  8643. @item --expression=@var{expr}
  8644. @itemx -e @var{expr}
  8645. Build the package or derivation @var{expr} evaluates to.
  8646. For example, @var{expr} may be @code{(@@ (gnu packages guile)
  8647. guile-1.8)}, which unambiguously designates this specific variant of
  8648. version 1.8 of Guile.
  8649. Alternatively, @var{expr} may be a G-expression, in which case it is used
  8650. as a build program passed to @code{gexp->derivation}
  8651. (@pxref{G-Expressions}).
  8652. Lastly, @var{expr} may refer to a zero-argument monadic procedure
  8653. (@pxref{The Store Monad}). The procedure must return a derivation as a
  8654. monadic value, which is then passed through @code{run-with-store}.
  8655. @item --source
  8656. @itemx -S
  8657. Build the source derivations of the packages, rather than the packages
  8658. themselves.
  8659. For instance, @code{guix build -S gcc} returns something like
  8660. @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
  8661. source tarball.
  8662. The returned source tarball is the result of applying any patches and
  8663. code snippets specified in the package @code{origin} (@pxref{Defining
  8664. Packages}).
  8665. @cindex source, verification
  8666. As with other derivations, the result of building a source derivation
  8667. can be verified using the @option{--check} option (@pxref{build-check}).
  8668. This is useful to validate that a (potentially already built or
  8669. substituted, thus cached) package source matches against its declared
  8670. hash.
  8671. Note that @command{guix build -S} compiles the sources only of the
  8672. specified packages. They do not include the sources of statically
  8673. linked dependencies and by themselves are insufficient for reproducing
  8674. the packages.
  8675. @item --sources
  8676. Fetch and return the source of @var{package-or-derivation} and all their
  8677. dependencies, recursively. This is a handy way to obtain a local copy
  8678. of all the source code needed to build @var{packages}, allowing you to
  8679. eventually build them even without network access. It is an extension
  8680. of the @option{--source} option and can accept one of the following
  8681. optional argument values:
  8682. @table @code
  8683. @item package
  8684. This value causes the @option{--sources} option to behave in the same way
  8685. as the @option{--source} option.
  8686. @item all
  8687. Build the source derivations of all packages, including any source that
  8688. might be listed as @code{inputs}. This is the default value.
  8689. @example
  8690. $ guix build --sources tzdata
  8691. The following derivations will be built:
  8692. /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
  8693. /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
  8694. @end example
  8695. @item transitive
  8696. Build the source derivations of all packages, as well of all transitive
  8697. inputs to the packages. This can be used e.g.@: to
  8698. prefetch package source for later offline building.
  8699. @example
  8700. $ guix build --sources=transitive tzdata
  8701. The following derivations will be built:
  8702. /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
  8703. /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
  8704. /gnu/store/@dots{}-grep-2.21.tar.xz.drv
  8705. /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
  8706. /gnu/store/@dots{}-make-4.1.tar.xz.drv
  8707. /gnu/store/@dots{}-bash-4.3.tar.xz.drv
  8708. @dots{}
  8709. @end example
  8710. @end table
  8711. @item --system=@var{system}
  8712. @itemx -s @var{system}
  8713. Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
  8714. the system type of the build host. The @command{guix build} command allows
  8715. you to repeat this option several times, in which case it builds for all the
  8716. specified systems; other commands ignore extraneous @option{-s} options.
  8717. @quotation Note
  8718. The @option{--system} flag is for @emph{native} compilation and must not
  8719. be confused with cross-compilation. See @option{--target} below for
  8720. information on cross-compilation.
  8721. @end quotation
  8722. An example use of this is on Linux-based systems, which can emulate
  8723. different personalities. For instance, passing
  8724. @option{--system=i686-linux} on an @code{x86_64-linux} system or
  8725. @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
  8726. you to build packages in a complete 32-bit environment.
  8727. @quotation Note
  8728. Building for an @code{armhf-linux} system is unconditionally enabled on
  8729. @code{aarch64-linux} machines, although certain aarch64 chipsets do not
  8730. allow for this functionality, notably the ThunderX.
  8731. @end quotation
  8732. Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
  8733. is enabled (@pxref{Virtualization Services,
  8734. @code{qemu-binfmt-service-type}}), you can build for any system for
  8735. which a QEMU @code{binfmt_misc} handler is installed.
  8736. Builds for a system other than that of the machine you are using can
  8737. also be offloaded to a remote machine of the right architecture.
  8738. @xref{Daemon Offload Setup}, for more information on offloading.
  8739. @item --target=@var{triplet}
  8740. @cindex cross-compilation
  8741. Cross-build for @var{triplet}, which must be a valid GNU triplet, such
  8742. as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
  8743. configuration triplets,, autoconf, Autoconf}).
  8744. @anchor{build-check}
  8745. @item --check
  8746. @cindex determinism, checking
  8747. @cindex reproducibility, checking
  8748. Rebuild @var{package-or-derivation}, which are already available in the
  8749. store, and raise an error if the build results are not bit-for-bit
  8750. identical.
  8751. This mechanism allows you to check whether previously installed
  8752. substitutes are genuine (@pxref{Substitutes}), or whether the build result
  8753. of a package is deterministic. @xref{Invoking guix challenge}, for more
  8754. background information and tools.
  8755. When used in conjunction with @option{--keep-failed}, the differing
  8756. output is kept in the store, under @file{/gnu/store/@dots{}-check}.
  8757. This makes it easy to look for differences between the two results.
  8758. @item --repair
  8759. @cindex repairing store items
  8760. @cindex corruption, recovering from
  8761. Attempt to repair the specified store items, if they are corrupt, by
  8762. re-downloading or rebuilding them.
  8763. This operation is not atomic and thus restricted to @code{root}.
  8764. @item --derivations
  8765. @itemx -d
  8766. Return the derivation paths, not the output paths, of the given
  8767. packages.
  8768. @item --root=@var{file}
  8769. @itemx -r @var{file}
  8770. @cindex GC roots, adding
  8771. @cindex garbage collector roots, adding
  8772. Make @var{file} a symlink to the result, and register it as a garbage
  8773. collector root.
  8774. Consequently, the results of this @command{guix build} invocation are
  8775. protected from garbage collection until @var{file} is removed. When
  8776. that option is omitted, build results are eligible for garbage
  8777. collection as soon as the build completes. @xref{Invoking guix gc}, for
  8778. more on GC roots.
  8779. @item --log-file
  8780. @cindex build logs, access
  8781. Return the build log file names or URLs for the given
  8782. @var{package-or-derivation}, or raise an error if build logs are
  8783. missing.
  8784. This works regardless of how packages or derivations are specified. For
  8785. instance, the following invocations are equivalent:
  8786. @example
  8787. guix build --log-file `guix build -d guile`
  8788. guix build --log-file `guix build guile`
  8789. guix build --log-file guile
  8790. guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
  8791. @end example
  8792. If a log is unavailable locally, and unless @option{--no-substitutes} is
  8793. passed, the command looks for a corresponding log on one of the
  8794. substitute servers (as specified with @option{--substitute-urls}).
  8795. So for instance, imagine you want to see the build log of GDB on MIPS,
  8796. but you are actually on an @code{x86_64} machine:
  8797. @example
  8798. $ guix build --log-file gdb -s aarch64-linux
  8799. https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
  8800. @end example
  8801. You can freely access a huge library of build logs!
  8802. @end table
  8803. @node Debugging Build Failures
  8804. @subsection Debugging Build Failures
  8805. @cindex build failures, debugging
  8806. When defining a new package (@pxref{Defining Packages}), you will
  8807. probably find yourself spending some time debugging and tweaking the
  8808. build until it succeeds. To do that, you need to operate the build
  8809. commands yourself in an environment as close as possible to the one the
  8810. build daemon uses.
  8811. To that end, the first thing to do is to use the @option{--keep-failed}
  8812. or @option{-K} option of @command{guix build}, which will keep the
  8813. failed build tree in @file{/tmp} or whatever directory you specified as
  8814. @env{TMPDIR} (@pxref{Common Build Options, @option{--keep-failed}}).
  8815. From there on, you can @command{cd} to the failed build tree and source
  8816. the @file{environment-variables} file, which contains all the
  8817. environment variable definitions that were in place when the build
  8818. failed. So let's say you're debugging a build failure in package
  8819. @code{foo}; a typical session would look like this:
  8820. @example
  8821. $ guix build foo -K
  8822. @dots{} @i{build fails}
  8823. $ cd /tmp/guix-build-foo.drv-0
  8824. $ source ./environment-variables
  8825. $ cd foo-1.2
  8826. @end example
  8827. Now, you can invoke commands as if you were the daemon (almost) and
  8828. troubleshoot your build process.
  8829. Sometimes it happens that, for example, a package's tests pass when you
  8830. run them manually but they fail when the daemon runs them. This can
  8831. happen because the daemon runs builds in containers where, unlike in our
  8832. environment above, network access is missing, @file{/bin/sh} does not
  8833. exist, etc. (@pxref{Build Environment Setup}).
  8834. In such cases, you may need to run inspect the build process from within
  8835. a container similar to the one the build daemon creates:
  8836. @example
  8837. $ guix build -K foo
  8838. @dots{}
  8839. $ cd /tmp/guix-build-foo.drv-0
  8840. $ guix environment --no-grafts -C foo --ad-hoc strace gdb
  8841. [env]# source ./environment-variables
  8842. [env]# cd foo-1.2
  8843. @end example
  8844. Here, @command{guix environment -C} creates a container and spawns a new
  8845. shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
  8846. strace gdb} part adds the @command{strace} and @command{gdb} commands to
  8847. the container, which you may find handy while debugging. The
  8848. @option{--no-grafts} option makes sure we get the exact same
  8849. environment, with ungrafted packages (@pxref{Security Updates}, for more
  8850. info on grafts).
  8851. To get closer to a container like that used by the build daemon, we can
  8852. remove @file{/bin/sh}:
  8853. @example
  8854. [env]# rm /bin/sh
  8855. @end example
  8856. (Don't worry, this is harmless: this is all happening in the throw-away
  8857. container created by @command{guix environment}.)
  8858. The @command{strace} command is probably not in the search path, but we
  8859. can run:
  8860. @example
  8861. [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
  8862. @end example
  8863. In this way, not only you will have reproduced the environment variables
  8864. the daemon uses, you will also be running the build process in a container
  8865. similar to the one the daemon uses.
  8866. @node Invoking guix edit
  8867. @section Invoking @command{guix edit}
  8868. @cindex @command{guix edit}
  8869. @cindex package definition, editing
  8870. So many packages, so many source files! The @command{guix edit} command
  8871. facilitates the life of users and packagers by pointing their editor at
  8872. the source file containing the definition of the specified packages.
  8873. For instance:
  8874. @example
  8875. guix edit gcc@@4.9 vim
  8876. @end example
  8877. @noindent
  8878. launches the program specified in the @env{VISUAL} or in the
  8879. @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
  8880. and that of Vim.
  8881. If you are using a Guix Git checkout (@pxref{Building from Git}), or
  8882. have created your own packages on @env{GUIX_PACKAGE_PATH}
  8883. (@pxref{Package Modules}), you will be able to edit the package
  8884. recipes. In other cases, you will be able to examine the read-only recipes
  8885. for packages currently in the store.
  8886. Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
  8887. @option{--load-path=@var{directory}} (or in short @option{-L
  8888. @var{directory}}) allows you to add @var{directory} to the front of the
  8889. package module search path and so make your own packages visible.
  8890. @node Invoking guix download
  8891. @section Invoking @command{guix download}
  8892. @cindex @command{guix download}
  8893. @cindex downloading package sources
  8894. When writing a package definition, developers typically need to download
  8895. a source tarball, compute its SHA256 hash, and write that
  8896. hash in the package definition (@pxref{Defining Packages}). The
  8897. @command{guix download} tool helps with this task: it downloads a file
  8898. from the given URI, adds it to the store, and prints both its file name
  8899. in the store and its SHA256 hash.
  8900. The fact that the downloaded file is added to the store saves bandwidth:
  8901. when the developer eventually tries to build the newly defined package
  8902. with @command{guix build}, the source tarball will not have to be
  8903. downloaded again because it is already in the store. It is also a
  8904. convenient way to temporarily stash files, which may be deleted
  8905. eventually (@pxref{Invoking guix gc}).
  8906. The @command{guix download} command supports the same URIs as used in
  8907. package definitions. In particular, it supports @code{mirror://} URIs.
  8908. @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
  8909. Guile bindings for GnuTLS are available in the user's environment; when
  8910. they are not available, an error is raised. @xref{Guile Preparations,
  8911. how to install the GnuTLS bindings for Guile,, gnutls-guile,
  8912. GnuTLS-Guile}, for more information.
  8913. @command{guix download} verifies HTTPS server certificates by loading
  8914. the certificates of X.509 authorities from the directory pointed to by
  8915. the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
  8916. Certificates}), unless @option{--no-check-certificate} is used.
  8917. The following options are available:
  8918. @table @code
  8919. @item --hash=@var{algorithm}
  8920. @itemx -H @var{algorithm}
  8921. Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
  8922. hash}, for more information.
  8923. @item --format=@var{fmt}
  8924. @itemx -f @var{fmt}
  8925. Write the hash in the format specified by @var{fmt}. For more
  8926. information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
  8927. @item --no-check-certificate
  8928. Do not validate the X.509 certificates of HTTPS servers.
  8929. When using this option, you have @emph{absolutely no guarantee} that you
  8930. are communicating with the authentic server responsible for the given
  8931. URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
  8932. @item --output=@var{file}
  8933. @itemx -o @var{file}
  8934. Save the downloaded file to @var{file} instead of adding it to the
  8935. store.
  8936. @end table
  8937. @node Invoking guix hash
  8938. @section Invoking @command{guix hash}
  8939. @cindex @command{guix hash}
  8940. The @command{guix hash} command computes the hash of a file.
  8941. It is primarily a convenience tool for anyone contributing to the
  8942. distribution: it computes the cryptographic hash of a file, which can be
  8943. used in the definition of a package (@pxref{Defining Packages}).
  8944. The general syntax is:
  8945. @example
  8946. guix hash @var{option} @var{file}
  8947. @end example
  8948. When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
  8949. hash of data read from standard input. @command{guix hash} has the
  8950. following options:
  8951. @table @code
  8952. @item --hash=@var{algorithm}
  8953. @itemx -H @var{algorithm}
  8954. Compute a hash using the specified @var{algorithm}, @code{sha256} by
  8955. default.
  8956. @var{algorithm} must the name of a cryptographic hash algorithm
  8957. supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
  8958. @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
  8959. Reference Manual}).
  8960. @item --format=@var{fmt}
  8961. @itemx -f @var{fmt}
  8962. Write the hash in the format specified by @var{fmt}.
  8963. Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
  8964. (@code{hex} and @code{hexadecimal} can be used as well).
  8965. If the @option{--format} option is not specified, @command{guix hash}
  8966. will output the hash in @code{nix-base32}. This representation is used
  8967. in the definitions of packages.
  8968. @item --recursive
  8969. @itemx -r
  8970. Compute the hash on @var{file} recursively.
  8971. In this case, the hash is computed on an archive containing @var{file},
  8972. including its children if it is a directory. Some of the metadata of
  8973. @var{file} is part of the archive; for instance, when @var{file} is a
  8974. regular file, the hash is different depending on whether @var{file} is
  8975. executable or not. Metadata such as time stamps has no impact on the
  8976. hash (@pxref{Invoking guix archive}).
  8977. @c FIXME: Replace xref above with xref to an ``Archive'' section when
  8978. @c it exists.
  8979. @item --exclude-vcs
  8980. @itemx -x
  8981. When combined with @option{--recursive}, exclude version control system
  8982. directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
  8983. @vindex git-fetch
  8984. As an example, here is how you would compute the hash of a Git checkout,
  8985. which is useful when using the @code{git-fetch} method (@pxref{origin
  8986. Reference}):
  8987. @example
  8988. $ git clone http://example.org/foo.git
  8989. $ cd foo
  8990. $ guix hash -rx .
  8991. @end example
  8992. @end table
  8993. @node Invoking guix import
  8994. @section Invoking @command{guix import}
  8995. @cindex importing packages
  8996. @cindex package import
  8997. @cindex package conversion
  8998. @cindex Invoking @command{guix import}
  8999. The @command{guix import} command is useful for people who would like to
  9000. add a package to the distribution with as little work as
  9001. possible---a legitimate demand. The command knows of a few
  9002. repositories from which it can ``import'' package metadata. The result
  9003. is a package definition, or a template thereof, in the format we know
  9004. (@pxref{Defining Packages}).
  9005. The general syntax is:
  9006. @example
  9007. guix import @var{importer} @var{options}@dots{}
  9008. @end example
  9009. @var{importer} specifies the source from which to import package
  9010. metadata, and @var{options} specifies a package identifier and other
  9011. options specific to @var{importer}.
  9012. Some of the importers rely on the ability to run the @command{gpgv} command.
  9013. For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
  9014. gnupg} if needed.
  9015. Currently, the available ``importers'' are:
  9016. @table @code
  9017. @item gnu
  9018. Import metadata for the given GNU package. This provides a template
  9019. for the latest version of that GNU package, including the hash of its
  9020. source tarball, and its canonical synopsis and description.
  9021. Additional information such as the package dependencies and its
  9022. license needs to be figured out manually.
  9023. For example, the following command returns a package definition for
  9024. GNU@tie{}Hello:
  9025. @example
  9026. guix import gnu hello
  9027. @end example
  9028. Specific command-line options are:
  9029. @table @code
  9030. @item --key-download=@var{policy}
  9031. As for @command{guix refresh}, specify the policy to handle missing
  9032. OpenPGP keys when verifying the package signature. @xref{Invoking guix
  9033. refresh, @option{--key-download}}.
  9034. @end table
  9035. @item pypi
  9036. @cindex pypi
  9037. Import metadata from the @uref{https://pypi.python.org/, Python Package
  9038. Index}. Information is taken from the JSON-formatted description
  9039. available at @code{pypi.python.org} and usually includes all the relevant
  9040. information, including package dependencies. For maximum efficiency, it
  9041. is recommended to install the @command{unzip} utility, so that the
  9042. importer can unzip Python wheels and gather data from them.
  9043. The command below imports metadata for the @code{itsdangerous} Python
  9044. package:
  9045. @example
  9046. guix import pypi itsdangerous
  9047. @end example
  9048. @table @code
  9049. @item --recursive
  9050. @itemx -r
  9051. Traverse the dependency graph of the given upstream package recursively
  9052. and generate package expressions for all those packages that are not yet
  9053. in Guix.
  9054. @end table
  9055. @item gem
  9056. @cindex gem
  9057. Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
  9058. is taken from the JSON-formatted description available at
  9059. @code{rubygems.org} and includes most relevant information, including
  9060. runtime dependencies. There are some caveats, however. The metadata
  9061. doesn't distinguish between synopses and descriptions, so the same string
  9062. is used for both fields. Additionally, the details of non-Ruby
  9063. dependencies required to build native extensions is unavailable and left
  9064. as an exercise to the packager.
  9065. The command below imports metadata for the @code{rails} Ruby package:
  9066. @example
  9067. guix import gem rails
  9068. @end example
  9069. @table @code
  9070. @item --recursive
  9071. @itemx -r
  9072. Traverse the dependency graph of the given upstream package recursively
  9073. and generate package expressions for all those packages that are not yet
  9074. in Guix.
  9075. @end table
  9076. @item cpan
  9077. @cindex CPAN
  9078. Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
  9079. Information is taken from the JSON-formatted metadata provided through
  9080. @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
  9081. relevant information, such as module dependencies. License information
  9082. should be checked closely. If Perl is available in the store, then the
  9083. @code{corelist} utility will be used to filter core modules out of the
  9084. list of dependencies.
  9085. The command command below imports metadata for the Acme::Boolean Perl
  9086. module:
  9087. @example
  9088. guix import cpan Acme::Boolean
  9089. @end example
  9090. @item cran
  9091. @cindex CRAN
  9092. @cindex Bioconductor
  9093. Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
  9094. central repository for the @uref{https://r-project.org, GNU@tie{}R
  9095. statistical and graphical environment}.
  9096. Information is extracted from the @file{DESCRIPTION} file of the package.
  9097. The command command below imports metadata for the Cairo R package:
  9098. @example
  9099. guix import cran Cairo
  9100. @end example
  9101. When @option{--recursive} is added, the importer will traverse the
  9102. dependency graph of the given upstream package recursively and generate
  9103. package expressions for all those packages that are not yet in Guix.
  9104. When @option{--style=specification} is added, the importer will generate
  9105. package definitions whose inputs are package specifications instead of
  9106. references to package variables. This is useful when generated package
  9107. definitions are to be appended to existing user modules, as the list of
  9108. used package modules need not be changed. The default is
  9109. @option{--style=variable}.
  9110. When @option{--archive=bioconductor} is added, metadata is imported from
  9111. @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
  9112. packages for the analysis and comprehension of high-throughput
  9113. genomic data in bioinformatics.
  9114. Information is extracted from the @file{DESCRIPTION} file contained in the
  9115. package archive.
  9116. The command below imports metadata for the GenomicRanges R package:
  9117. @example
  9118. guix import cran --archive=bioconductor GenomicRanges
  9119. @end example
  9120. Finally, you can also import R packages that have not yet been published on
  9121. CRAN or Bioconductor as long as they are in a git repository. Use
  9122. @option{--archive=git} followed by the URL of the git repository:
  9123. @example
  9124. guix import cran --archive=git https://github.com/immunogenomics/harmony
  9125. @end example
  9126. @item texlive
  9127. @cindex TeX Live
  9128. @cindex CTAN
  9129. Import metadata from @uref{https://www.ctan.org/, CTAN}, the
  9130. comprehensive TeX archive network for TeX packages that are part of the
  9131. @uref{https://www.tug.org/texlive/, TeX Live distribution}.
  9132. Information about the package is obtained through the XML API provided
  9133. by CTAN, while the source code is downloaded from the SVN repository of
  9134. the Tex Live project. This is done because the CTAN does not keep
  9135. versioned archives.
  9136. The command command below imports metadata for the @code{fontspec}
  9137. TeX package:
  9138. @example
  9139. guix import texlive fontspec
  9140. @end example
  9141. When @option{--archive=@var{directory}} is added, the source code is
  9142. downloaded not from the @file{latex} sub-directory of the
  9143. @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
  9144. the specified sibling @var{directory} under the same root.
  9145. The command below imports metadata for the @code{ifxetex} package from
  9146. CTAN while fetching the sources from the directory
  9147. @file{texmf/source/generic}:
  9148. @example
  9149. guix import texlive --archive=generic ifxetex
  9150. @end example
  9151. @item json
  9152. @cindex JSON, import
  9153. Import package metadata from a local JSON file. Consider the following
  9154. example package definition in JSON format:
  9155. @example
  9156. @{
  9157. "name": "hello",
  9158. "version": "2.10",
  9159. "source": "mirror://gnu/hello/hello-2.10.tar.gz",
  9160. "build-system": "gnu",
  9161. "home-page": "https://www.gnu.org/software/hello/",
  9162. "synopsis": "Hello, GNU world: An example GNU package",
  9163. "description": "GNU Hello prints a greeting.",
  9164. "license": "GPL-3.0+",
  9165. "native-inputs": ["gettext"]
  9166. @}
  9167. @end example
  9168. The field names are the same as for the @code{<package>} record
  9169. (@xref{Defining Packages}). References to other packages are provided
  9170. as JSON lists of quoted package specification strings such as
  9171. @code{guile} or @code{guile@@2.0}.
  9172. The importer also supports a more explicit source definition using the
  9173. common fields for @code{<origin>} records:
  9174. @example
  9175. @{
  9176. @dots{}
  9177. "source": @{
  9178. "method": "url-fetch",
  9179. "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
  9180. "sha256": @{
  9181. "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
  9182. @}
  9183. @}
  9184. @dots{}
  9185. @}
  9186. @end example
  9187. The command below reads metadata from the JSON file @code{hello.json}
  9188. and outputs a package expression:
  9189. @example
  9190. guix import json hello.json
  9191. @end example
  9192. @item nix
  9193. Import metadata from a local copy of the source of the
  9194. @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
  9195. relies on the @command{nix-instantiate} command of
  9196. @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
  9197. typically written in a mixture of Nix-language and Bash code. This
  9198. command only imports the high-level package structure that is written in
  9199. the Nix language. It normally includes all the basic fields of a
  9200. package definition.
  9201. When importing a GNU package, the synopsis and descriptions are replaced
  9202. by their canonical upstream variant.
  9203. Usually, you will first need to do:
  9204. @example
  9205. export NIX_REMOTE=daemon
  9206. @end example
  9207. @noindent
  9208. so that @command{nix-instantiate} does not try to open the Nix database.
  9209. As an example, the command below imports the package definition of
  9210. LibreOffice (more precisely, it imports the definition of the package
  9211. bound to the @code{libreoffice} top-level attribute):
  9212. @example
  9213. guix import nix ~/path/to/nixpkgs libreoffice
  9214. @end example
  9215. @item hackage
  9216. @cindex hackage
  9217. Import metadata from the Haskell community's central package archive
  9218. @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
  9219. Cabal files and includes all the relevant information, including package
  9220. dependencies.
  9221. Specific command-line options are:
  9222. @table @code
  9223. @item --stdin
  9224. @itemx -s
  9225. Read a Cabal file from standard input.
  9226. @item --no-test-dependencies
  9227. @itemx -t
  9228. Do not include dependencies required only by the test suites.
  9229. @item --cabal-environment=@var{alist}
  9230. @itemx -e @var{alist}
  9231. @var{alist} is a Scheme alist defining the environment in which the
  9232. Cabal conditionals are evaluated. The accepted keys are: @code{os},
  9233. @code{arch}, @code{impl} and a string representing the name of a flag.
  9234. The value associated with a flag has to be either the symbol
  9235. @code{true} or @code{false}. The value associated with other keys
  9236. has to conform to the Cabal file format definition. The default value
  9237. associated with the keys @code{os}, @code{arch} and @code{impl} is
  9238. @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
  9239. @item --recursive
  9240. @itemx -r
  9241. Traverse the dependency graph of the given upstream package recursively
  9242. and generate package expressions for all those packages that are not yet
  9243. in Guix.
  9244. @end table
  9245. The command below imports metadata for the latest version of the
  9246. HTTP Haskell package without including test dependencies and
  9247. specifying the value of the flag @samp{network-uri} as @code{false}:
  9248. @example
  9249. guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
  9250. @end example
  9251. A specific package version may optionally be specified by following the
  9252. package name by an at-sign and a version number as in the following example:
  9253. @example
  9254. guix import hackage mtl@@2.1.3.1
  9255. @end example
  9256. @item stackage
  9257. @cindex stackage
  9258. The @code{stackage} importer is a wrapper around the @code{hackage} one.
  9259. It takes a package name, looks up the package version included in a
  9260. long-term support (LTS) @uref{https://www.stackage.org, Stackage}
  9261. release and uses the @code{hackage} importer to retrieve its metadata.
  9262. Note that it is up to you to select an LTS release compatible with the
  9263. GHC compiler used by Guix.
  9264. Specific command-line options are:
  9265. @table @code
  9266. @item --no-test-dependencies
  9267. @itemx -t
  9268. Do not include dependencies required only by the test suites.
  9269. @item --lts-version=@var{version}
  9270. @itemx -l @var{version}
  9271. @var{version} is the desired LTS release version. If omitted the latest
  9272. release is used.
  9273. @item --recursive
  9274. @itemx -r
  9275. Traverse the dependency graph of the given upstream package recursively
  9276. and generate package expressions for all those packages that are not yet
  9277. in Guix.
  9278. @end table
  9279. The command below imports metadata for the HTTP Haskell package
  9280. included in the LTS Stackage release version 7.18:
  9281. @example
  9282. guix import stackage --lts-version=7.18 HTTP
  9283. @end example
  9284. @item elpa
  9285. @cindex elpa
  9286. Import metadata from an Emacs Lisp Package Archive (ELPA) package
  9287. repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
  9288. Specific command-line options are:
  9289. @table @code
  9290. @item --archive=@var{repo}
  9291. @itemx -a @var{repo}
  9292. @var{repo} identifies the archive repository from which to retrieve the
  9293. information. Currently the supported repositories and their identifiers
  9294. are:
  9295. @itemize -
  9296. @item
  9297. @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
  9298. identifier. This is the default.
  9299. Packages from @code{elpa.gnu.org} are signed with one of the keys
  9300. contained in the GnuPG keyring at
  9301. @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
  9302. @code{emacs} package (@pxref{Package Installation, ELPA package
  9303. signatures,, emacs, The GNU Emacs Manual}).
  9304. @item
  9305. @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
  9306. @code{melpa-stable} identifier.
  9307. @item
  9308. @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
  9309. identifier.
  9310. @end itemize
  9311. @item --recursive
  9312. @itemx -r
  9313. Traverse the dependency graph of the given upstream package recursively
  9314. and generate package expressions for all those packages that are not yet
  9315. in Guix.
  9316. @end table
  9317. @item crate
  9318. @cindex crate
  9319. Import metadata from the crates.io Rust package repository
  9320. @uref{https://crates.io, crates.io}, as in this example:
  9321. @example
  9322. guix import crate blake2-rfc
  9323. @end example
  9324. The crate importer also allows you to specify a version string:
  9325. @example
  9326. guix import crate constant-time-eq@@0.1.0
  9327. @end example
  9328. Additional options include:
  9329. @table @code
  9330. @item --recursive
  9331. @itemx -r
  9332. Traverse the dependency graph of the given upstream package recursively
  9333. and generate package expressions for all those packages that are not yet
  9334. in Guix.
  9335. @end table
  9336. @item opam
  9337. @cindex OPAM
  9338. @cindex OCaml
  9339. Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
  9340. repository used by the OCaml community.
  9341. Additional options include:
  9342. @table @code
  9343. @item --recursive
  9344. @itemx -r
  9345. Traverse the dependency graph of the given upstream package recursively
  9346. and generate package expressions for all those packages that are not yet
  9347. in Guix.
  9348. @item --repo
  9349. Select the given repository (a repository name). Possible values include:
  9350. @itemize
  9351. @item @code{opam}, the default opam repository,
  9352. @item @code{coq} or @code{coq-released}, the stable repository for coq packages,
  9353. @item @code{coq-core-dev}, the repository that contains development versions of coq,
  9354. @item @code{coq-extra-dev}, the repository that contains development versions
  9355. of coq packages.
  9356. @end itemize
  9357. @end table
  9358. @item go
  9359. @cindex go
  9360. Import metadata for a Go module using
  9361. @uref{https://proxy.golang.org, proxy.golang.org}.
  9362. This importer is highly experimental. See the source code for more info
  9363. about the current state.
  9364. @example
  9365. guix import go gopkg.in/yaml.v2
  9366. @end example
  9367. Additional options include:
  9368. @table @code
  9369. @item --recursive
  9370. @itemx -r
  9371. Traverse the dependency graph of the given upstream package recursively
  9372. and generate package expressions for all those packages that are not yet
  9373. in Guix.
  9374. @end table
  9375. @end table
  9376. The structure of the @command{guix import} code is modular. It would be
  9377. useful to have more importers for other package formats, and your help
  9378. is welcome here (@pxref{Contributing}).
  9379. @node Invoking guix refresh
  9380. @section Invoking @command{guix refresh}
  9381. @cindex @command {guix refresh}
  9382. The primary audience of the @command{guix refresh} command is developers
  9383. of the GNU software distribution. By default, it reports any packages
  9384. provided by the distribution that are outdated compared to the latest
  9385. upstream version, like this:
  9386. @example
  9387. $ guix refresh
  9388. gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
  9389. gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
  9390. @end example
  9391. Alternatively, one can specify packages to consider, in which case a
  9392. warning is emitted for packages that lack an updater:
  9393. @example
  9394. $ guix refresh coreutils guile guile-ssh
  9395. gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
  9396. gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
  9397. @end example
  9398. @command{guix refresh} browses the upstream repository of each package and determines
  9399. the highest version number of the releases therein. The command
  9400. knows how to update specific types of packages: GNU packages, ELPA
  9401. packages, etc.---see the documentation for @option{--type} below. There
  9402. are many packages, though, for which it lacks a method to determine
  9403. whether a new upstream release is available. However, the mechanism is
  9404. extensible, so feel free to get in touch with us to add a new method!
  9405. @table @code
  9406. @item --recursive
  9407. Consider the packages specified, and all the packages upon which they depend.
  9408. @example
  9409. $ guix refresh --recursive coreutils
  9410. gnu/packages/acl.scm:40:13: acl would be upgraded from 2.2.53 to 2.3.1
  9411. gnu/packages/m4.scm:30:12: 1.4.18 is already the latest version of m4
  9412. gnu/packages/xml.scm:68:2: warning: no updater for expat
  9413. gnu/packages/multiprecision.scm:40:12: 6.1.2 is already the latest version of gmp
  9414. @dots{}
  9415. @end example
  9416. @end table
  9417. Sometimes the upstream name differs from the package name used in Guix,
  9418. and @command{guix refresh} needs a little help. Most updaters honor the
  9419. @code{upstream-name} property in package definitions, which can be used
  9420. to that effect:
  9421. @lisp
  9422. (define-public network-manager
  9423. (package
  9424. (name "network-manager")
  9425. ;; @dots{}
  9426. (properties '((upstream-name . "NetworkManager")))))
  9427. @end lisp
  9428. When passed @option{--update}, it modifies distribution source files to
  9429. update the version numbers and source tarball hashes of those package
  9430. recipes (@pxref{Defining Packages}). This is achieved by downloading
  9431. each package's latest source tarball and its associated OpenPGP
  9432. signature, authenticating the downloaded tarball against its signature
  9433. using @command{gpgv}, and finally computing its hash---note that GnuPG must be
  9434. installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
  9435. When the public
  9436. key used to sign the tarball is missing from the user's keyring, an
  9437. attempt is made to automatically retrieve it from a public key server;
  9438. when this is successful, the key is added to the user's keyring; otherwise,
  9439. @command{guix refresh} reports an error.
  9440. The following options are supported:
  9441. @table @code
  9442. @item --expression=@var{expr}
  9443. @itemx -e @var{expr}
  9444. Consider the package @var{expr} evaluates to.
  9445. This is useful to precisely refer to a package, as in this example:
  9446. @example
  9447. guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
  9448. @end example
  9449. This command lists the dependents of the ``final'' libc (essentially all
  9450. the packages).
  9451. @item --update
  9452. @itemx -u
  9453. Update distribution source files (package recipes) in place. This is
  9454. usually run from a checkout of the Guix source tree (@pxref{Running
  9455. Guix Before It Is Installed}):
  9456. @example
  9457. $ ./pre-inst-env guix refresh -s non-core -u
  9458. @end example
  9459. @xref{Defining Packages}, for more information on package definitions.
  9460. @item --select=[@var{subset}]
  9461. @itemx -s @var{subset}
  9462. Select all the packages in @var{subset}, one of @code{core} or
  9463. @code{non-core}.
  9464. The @code{core} subset refers to all the packages at the core of the
  9465. distribution---i.e., packages that are used to build ``everything
  9466. else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
  9467. changing one of these packages in the distribution entails a rebuild of
  9468. all the others. Thus, such updates are an inconvenience to users in
  9469. terms of build time or bandwidth used to achieve the upgrade.
  9470. The @code{non-core} subset refers to the remaining packages. It is
  9471. typically useful in cases where an update of the core packages would be
  9472. inconvenient.
  9473. @item --manifest=@var{file}
  9474. @itemx -m @var{file}
  9475. Select all the packages from the manifest in @var{file}. This is useful to
  9476. check if any packages of the user manifest can be updated.
  9477. @item --type=@var{updater}
  9478. @itemx -t @var{updater}
  9479. Select only packages handled by @var{updater} (may be a comma-separated
  9480. list of updaters). Currently, @var{updater} may be one of:
  9481. @table @code
  9482. @item gnu
  9483. the updater for GNU packages;
  9484. @item savannah
  9485. the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
  9486. @item gnome
  9487. the updater for GNOME packages;
  9488. @item kde
  9489. the updater for KDE packages;
  9490. @item xorg
  9491. the updater for X.org packages;
  9492. @item kernel.org
  9493. the updater for packages hosted on kernel.org;
  9494. @item elpa
  9495. the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
  9496. @item cran
  9497. the updater for @uref{https://cran.r-project.org/, CRAN} packages;
  9498. @item bioconductor
  9499. the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
  9500. @item cpan
  9501. the updater for @uref{https://www.cpan.org/, CPAN} packages;
  9502. @item pypi
  9503. the updater for @uref{https://pypi.python.org, PyPI} packages.
  9504. @item gem
  9505. the updater for @uref{https://rubygems.org, RubyGems} packages.
  9506. @item github
  9507. the updater for @uref{https://github.com, GitHub} packages.
  9508. @item hackage
  9509. the updater for @uref{https://hackage.haskell.org, Hackage} packages.
  9510. @item stackage
  9511. the updater for @uref{https://www.stackage.org, Stackage} packages.
  9512. @item crate
  9513. the updater for @uref{https://crates.io, Crates} packages.
  9514. @item launchpad
  9515. the updater for @uref{https://launchpad.net, Launchpad} packages.
  9516. @item generic-html
  9517. a generic updater that crawls the HTML page where the source tarball of
  9518. the package is hosted, when applicable.
  9519. @end table
  9520. For instance, the following command only checks for updates of Emacs
  9521. packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
  9522. @example
  9523. $ guix refresh --type=elpa,cran
  9524. gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
  9525. gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
  9526. @end example
  9527. @end table
  9528. In addition, @command{guix refresh} can be passed one or more package
  9529. names, as in this example:
  9530. @example
  9531. $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
  9532. @end example
  9533. @noindent
  9534. The command above specifically updates the @code{emacs} and
  9535. @code{idutils} packages. The @option{--select} option would have no
  9536. effect in this case.
  9537. When considering whether to upgrade a package, it is sometimes
  9538. convenient to know which packages would be affected by the upgrade and
  9539. should be checked for compatibility. For this the following option may
  9540. be used when passing @command{guix refresh} one or more package names:
  9541. @table @code
  9542. @item --list-updaters
  9543. @itemx -L
  9544. List available updaters and exit (see @option{--type} above).
  9545. For each updater, display the fraction of packages it covers; at the
  9546. end, display the fraction of packages covered by all these updaters.
  9547. @item --list-dependent
  9548. @itemx -l
  9549. List top-level dependent packages that would need to be rebuilt as a
  9550. result of upgrading one or more packages.
  9551. @xref{Invoking guix graph, the @code{reverse-package} type of
  9552. @command{guix graph}}, for information on how to visualize the list of
  9553. dependents of a package.
  9554. @end table
  9555. Be aware that the @option{--list-dependent} option only
  9556. @emph{approximates} the rebuilds that would be required as a result of
  9557. an upgrade. More rebuilds might be required under some circumstances.
  9558. @example
  9559. $ guix refresh --list-dependent flex
  9560. Building the following 120 packages would ensure 213 dependent packages are rebuilt:
  9561. hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
  9562. @end example
  9563. The command above lists a set of packages that could be built to check
  9564. for compatibility with an upgraded @code{flex} package.
  9565. @table @code
  9566. @item --list-transitive
  9567. List all the packages which one or more packages depend upon.
  9568. @example
  9569. $ guix refresh --list-transitive flex
  9570. flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
  9571. bison@@3.0.5 indent@@2.2.10 tar@@1.30 gzip@@1.9 bzip2@@1.0.6 xz@@5.2.4 file@@5.33 @dots{}
  9572. @end example
  9573. @end table
  9574. The command above lists a set of packages which, when changed, would cause
  9575. @code{flex} to be rebuilt.
  9576. The following options can be used to customize GnuPG operation:
  9577. @table @code
  9578. @item --gpg=@var{command}
  9579. Use @var{command} as the GnuPG 2.x command. @var{command} is searched
  9580. for in @code{$PATH}.
  9581. @item --keyring=@var{file}
  9582. Use @var{file} as the keyring for upstream keys. @var{file} must be in the
  9583. @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
  9584. and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
  9585. (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
  9586. information on a tool to manipulate keybox files).
  9587. When this option is omitted, @command{guix refresh} uses
  9588. @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
  9589. signing keys. OpenPGP signatures are checked against keys from this keyring;
  9590. missing keys are downloaded to this keyring as well (see
  9591. @option{--key-download} below).
  9592. You can export keys from your default GPG keyring into a keybox file using
  9593. commands like this one:
  9594. @example
  9595. gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
  9596. @end example
  9597. Likewise, you can fetch keys to a specific keybox file like this:
  9598. @example
  9599. gpg --no-default-keyring --keyring mykeyring.kbx \
  9600. --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
  9601. @end example
  9602. @xref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
  9603. Privacy Guard}, for more information on GPG's @option{--keyring} option.
  9604. @item --key-download=@var{policy}
  9605. Handle missing OpenPGP keys according to @var{policy}, which may be one
  9606. of:
  9607. @table @code
  9608. @item always
  9609. Always download missing OpenPGP keys from the key server, and add them
  9610. to the user's GnuPG keyring.
  9611. @item never
  9612. Never try to download missing OpenPGP keys. Instead just bail out.
  9613. @item interactive
  9614. When a package signed with an unknown OpenPGP key is encountered, ask
  9615. the user whether to download it or not. This is the default behavior.
  9616. @end table
  9617. @item --key-server=@var{host}
  9618. Use @var{host} as the OpenPGP key server when importing a public key.
  9619. @item --load-path=@var{directory}
  9620. Add @var{directory} to the front of the package module search path
  9621. (@pxref{Package Modules}).
  9622. This allows users to define their own packages and make them visible to
  9623. the command-line tools.
  9624. @end table
  9625. The @code{github} updater uses the
  9626. @uref{https://developer.github.com/v3/, GitHub API} to query for new
  9627. releases. When used repeatedly e.g.@: when refreshing all packages,
  9628. GitHub will eventually refuse to answer any further API requests. By
  9629. default 60 API requests per hour are allowed, and a full refresh on all
  9630. GitHub packages in Guix requires more than this. Authentication with
  9631. GitHub through the use of an API token alleviates these limits. To use
  9632. an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
  9633. token procured from @uref{https://github.com/settings/tokens} or
  9634. otherwise.
  9635. @node Invoking guix lint
  9636. @section Invoking @command{guix lint}
  9637. @cindex @command{guix lint}
  9638. @cindex package, checking for errors
  9639. The @command{guix lint} command is meant to help package developers avoid
  9640. common errors and use a consistent style. It runs a number of checks on
  9641. a given set of packages in order to find common mistakes in their
  9642. definitions. Available @dfn{checkers} include (see
  9643. @option{--list-checkers} for a complete list):
  9644. @table @code
  9645. @item synopsis
  9646. @itemx description
  9647. Validate certain typographical and stylistic rules about package
  9648. descriptions and synopses.
  9649. @item inputs-should-be-native
  9650. Identify inputs that should most likely be native inputs.
  9651. @item source
  9652. @itemx home-page
  9653. @itemx mirror-url
  9654. @itemx github-url
  9655. @itemx source-file-name
  9656. Probe @code{home-page} and @code{source} URLs and report those that are
  9657. invalid. Suggest a @code{mirror://} URL when applicable. If the
  9658. @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
  9659. URL@. Check that the source file name is meaningful, e.g.@: is not just a
  9660. version number or ``git-checkout'', without a declared @code{file-name}
  9661. (@pxref{origin Reference}).
  9662. @item source-unstable-tarball
  9663. Parse the @code{source} URL to determine if a tarball from GitHub is
  9664. autogenerated or if it is a release tarball. Unfortunately GitHub's
  9665. autogenerated tarballs are sometimes regenerated.
  9666. @item derivation
  9667. Check that the derivation of the given packages can be successfully
  9668. computed for all the supported systems (@pxref{Derivations}).
  9669. @item profile-collisions
  9670. Check whether installing the given packages in a profile would lead to
  9671. collisions. Collisions occur when several packages with the same name
  9672. but a different version or a different store file name are propagated.
  9673. @xref{package Reference, @code{propagated-inputs}}, for more information
  9674. on propagated inputs.
  9675. @item archival
  9676. @cindex Software Heritage, source code archive
  9677. @cindex archival of source code, Software Heritage
  9678. Checks whether the package's source code is archived at
  9679. @uref{https://www.softwareheritage.org, Software Heritage}.
  9680. When the source code that is not archived comes from a version-control system
  9681. (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
  9682. ``save'' request so that it eventually archives it. This ensures that the
  9683. source will remain available in the long term, and that Guix can fall back to
  9684. Software Heritage should the source code disappear from its original host.
  9685. The status of recent ``save'' requests can be
  9686. @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
  9687. When source code is a tarball obtained with @code{url-fetch}, simply print a
  9688. message when it is not archived. As of this writing, Software Heritage does
  9689. not allow requests to save arbitrary tarballs; we are working on ways to
  9690. ensure that non-VCS source code is also archived.
  9691. Software Heritage
  9692. @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
  9693. request rate per IP address}. When the limit is reached, @command{guix lint}
  9694. prints a message and the @code{archival} checker stops doing anything until
  9695. that limit has been reset.
  9696. @item cve
  9697. @cindex security vulnerabilities
  9698. @cindex CVE, Common Vulnerabilities and Exposures
  9699. Report known vulnerabilities found in the Common Vulnerabilities and
  9700. Exposures (CVE) databases of the current and past year
  9701. @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
  9702. NIST}.
  9703. To view information about a particular vulnerability, visit pages such as:
  9704. @itemize
  9705. @item
  9706. @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
  9707. @item
  9708. @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
  9709. @end itemize
  9710. @noindent
  9711. where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
  9712. @code{CVE-2015-7554}.
  9713. Package developers can specify in package recipes the
  9714. @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
  9715. name and version of the package when they differ from the name or version
  9716. that Guix uses, as in this example:
  9717. @lisp
  9718. (package
  9719. (name "grub")
  9720. ;; @dots{}
  9721. ;; CPE calls this package "grub2".
  9722. (properties '((cpe-name . "grub2")
  9723. (cpe-version . "2.3"))))
  9724. @end lisp
  9725. @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
  9726. Some entries in the CVE database do not specify which version of a
  9727. package they apply to, and would thus ``stick around'' forever. Package
  9728. developers who found CVE alerts and verified they can be ignored can
  9729. declare them as in this example:
  9730. @lisp
  9731. (package
  9732. (name "t1lib")
  9733. ;; @dots{}
  9734. ;; These CVEs no longer apply and can be safely ignored.
  9735. (properties `((lint-hidden-cve . ("CVE-2011-0433"
  9736. "CVE-2011-1553"
  9737. "CVE-2011-1554"
  9738. "CVE-2011-5244")))))
  9739. @end lisp
  9740. @item formatting
  9741. Warn about obvious source code formatting issues: trailing white space,
  9742. use of tabulations, etc.
  9743. @end table
  9744. The general syntax is:
  9745. @example
  9746. guix lint @var{options} @var{package}@dots{}
  9747. @end example
  9748. If no package is given on the command line, then all packages are checked.
  9749. The @var{options} may be zero or more of the following:
  9750. @table @code
  9751. @item --list-checkers
  9752. @itemx -l
  9753. List and describe all the available checkers that will be run on packages
  9754. and exit.
  9755. @item --checkers
  9756. @itemx -c
  9757. Only enable the checkers specified in a comma-separated list using the
  9758. names returned by @option{--list-checkers}.
  9759. @item --exclude
  9760. @itemx -x
  9761. Only disable the checkers specified in a comma-separated list using the
  9762. names returned by @option{--list-checkers}.
  9763. @item --no-network
  9764. @itemx -n
  9765. Only enable the checkers that do not depend on Internet access.
  9766. @item --load-path=@var{directory}
  9767. @itemx -L @var{directory}
  9768. Add @var{directory} to the front of the package module search path
  9769. (@pxref{Package Modules}).
  9770. This allows users to define their own packages and make them visible to
  9771. the command-line tools.
  9772. @end table
  9773. @node Invoking guix size
  9774. @section Invoking @command{guix size}
  9775. @cindex size
  9776. @cindex package size
  9777. @cindex closure
  9778. @cindex @command{guix size}
  9779. The @command{guix size} command helps package developers profile the
  9780. disk usage of packages. It is easy to overlook the impact of an
  9781. additional dependency added to a package, or the impact of using a
  9782. single output for a package that could easily be split (@pxref{Packages
  9783. with Multiple Outputs}). Such are the typical issues that
  9784. @command{guix size} can highlight.
  9785. The command can be passed one or more package specifications
  9786. such as @code{gcc@@4.8}
  9787. or @code{guile:debug}, or a file name in the store. Consider this
  9788. example:
  9789. @example
  9790. $ guix size coreutils
  9791. store item total self
  9792. /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
  9793. /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
  9794. /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
  9795. /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
  9796. /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
  9797. /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
  9798. /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
  9799. /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
  9800. total: 78.9 MiB
  9801. @end example
  9802. @cindex closure
  9803. The store items listed here constitute the @dfn{transitive closure} of
  9804. Coreutils---i.e., Coreutils and all its dependencies, recursively---as
  9805. would be returned by:
  9806. @example
  9807. $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
  9808. @end example
  9809. Here the output shows three columns next to store items. The first column,
  9810. labeled ``total'', shows the size in mebibytes (MiB) of the closure of
  9811. the store item---that is, its own size plus the size of all its
  9812. dependencies. The next column, labeled ``self'', shows the size of the
  9813. item itself. The last column shows the ratio of the size of the item
  9814. itself to the space occupied by all the items listed here.
  9815. In this example, we see that the closure of Coreutils weighs in at
  9816. 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
  9817. libraries. (That libc and GCC's libraries represent a large fraction of
  9818. the closure is not a problem @i{per se} because they are always available
  9819. on the system anyway.)
  9820. Since the command also accepts store file names, assessing the size of
  9821. a build result is straightforward:
  9822. @example
  9823. guix size $(guix system build config.scm)
  9824. @end example
  9825. When the package(s) passed to @command{guix size} are available in the
  9826. store@footnote{More precisely, @command{guix size} looks for the
  9827. @emph{ungrafted} variant of the given package(s), as returned by
  9828. @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
  9829. for information on grafts.}, @command{guix size} queries the daemon to determine its
  9830. dependencies, and measures its size in the store, similar to @command{du
  9831. -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
  9832. Coreutils}).
  9833. When the given packages are @emph{not} in the store, @command{guix size}
  9834. reports information based on the available substitutes
  9835. (@pxref{Substitutes}). This makes it possible it to profile disk usage of
  9836. store items that are not even on disk, only available remotely.
  9837. You can also specify several package names:
  9838. @example
  9839. $ guix size coreutils grep sed bash
  9840. store item total self
  9841. /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
  9842. /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
  9843. /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
  9844. /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
  9845. @dots{}
  9846. total: 102.3 MiB
  9847. @end example
  9848. @noindent
  9849. In this example we see that the combination of the four packages takes
  9850. 102.3@tie{}MiB in total, which is much less than the sum of each closure
  9851. since they have a lot of dependencies in common.
  9852. When looking at the profile returned by @command{guix size}, you may
  9853. find yourself wondering why a given package shows up in the profile at
  9854. all. To understand it, you can use @command{guix graph --path -t
  9855. references} to display the shortest path between the two packages
  9856. (@pxref{Invoking guix graph}).
  9857. The available options are:
  9858. @table @option
  9859. @item --substitute-urls=@var{urls}
  9860. Use substitute information from @var{urls}.
  9861. @xref{client-substitute-urls, the same option for @code{guix build}}.
  9862. @item --sort=@var{key}
  9863. Sort lines according to @var{key}, one of the following options:
  9864. @table @code
  9865. @item self
  9866. the size of each item (the default);
  9867. @item closure
  9868. the total size of the item's closure.
  9869. @end table
  9870. @item --map-file=@var{file}
  9871. Write a graphical map of disk usage in PNG format to @var{file}.
  9872. For the example above, the map looks like this:
  9873. @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
  9874. produced by @command{guix size}}
  9875. This option requires that
  9876. @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
  9877. installed and visible in Guile's module search path. When that is not
  9878. the case, @command{guix size} fails as it tries to load it.
  9879. @item --system=@var{system}
  9880. @itemx -s @var{system}
  9881. Consider packages for @var{system}---e.g., @code{x86_64-linux}.
  9882. @item --load-path=@var{directory}
  9883. @itemx -L @var{directory}
  9884. Add @var{directory} to the front of the package module search path
  9885. (@pxref{Package Modules}).
  9886. This allows users to define their own packages and make them visible to
  9887. the command-line tools.
  9888. @end table
  9889. @node Invoking guix graph
  9890. @section Invoking @command{guix graph}
  9891. @cindex DAG
  9892. @cindex @command{guix graph}
  9893. @cindex package dependencies
  9894. Packages and their dependencies form a @dfn{graph}, specifically a
  9895. directed acyclic graph (DAG). It can quickly become difficult to have a
  9896. mental model of the package DAG, so the @command{guix graph} command
  9897. provides a visual representation of the DAG@. By default,
  9898. @command{guix graph} emits a DAG representation in the input format of
  9899. @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
  9900. directly to the @command{dot} command of Graphviz. It can also emit an
  9901. HTML page with embedded JavaScript code to display a ``chord diagram''
  9902. in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
  9903. emit Cypher queries to construct a graph in a graph database supporting
  9904. the @uref{https://www.opencypher.org/, openCypher} query language. With
  9905. @option{--path}, it simply displays the shortest path between two
  9906. packages. The general syntax is:
  9907. @example
  9908. guix graph @var{options} @var{package}@dots{}
  9909. @end example
  9910. For example, the following command generates a PDF file representing the
  9911. package DAG for the GNU@tie{}Core Utilities, showing its build-time
  9912. dependencies:
  9913. @example
  9914. guix graph coreutils | dot -Tpdf > dag.pdf
  9915. @end example
  9916. The output looks like this:
  9917. @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
  9918. Nice little graph, no?
  9919. You may find it more pleasant to navigate the graph interactively with
  9920. @command{xdot} (from the @code{xdot} package):
  9921. @example
  9922. guix graph coreutils | xdot -
  9923. @end example
  9924. But there is more than one graph! The one above is concise: it is the
  9925. graph of package objects, omitting implicit inputs such as GCC, libc,
  9926. grep, etc. It is often useful to have such a concise graph, but
  9927. sometimes one may want to see more details. @command{guix graph} supports
  9928. several types of graphs, allowing you to choose the level of detail:
  9929. @table @code
  9930. @item package
  9931. This is the default type used in the example above. It shows the DAG of
  9932. package objects, excluding implicit dependencies. It is concise, but
  9933. filters out many details.
  9934. @item reverse-package
  9935. This shows the @emph{reverse} DAG of packages. For example:
  9936. @example
  9937. guix graph --type=reverse-package ocaml
  9938. @end example
  9939. ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
  9940. you are also interested in cases where OCaml is an implicit dependency, see
  9941. @code{reverse-bag} below).
  9942. Note that for core packages this can yield huge graphs. If all you want
  9943. is to know the number of packages that depend on a given package, use
  9944. @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
  9945. @option{--list-dependent}}).
  9946. @item bag-emerged
  9947. This is the package DAG, @emph{including} implicit inputs.
  9948. For instance, the following command:
  9949. @example
  9950. guix graph --type=bag-emerged coreutils
  9951. @end example
  9952. ...@: yields this bigger graph:
  9953. @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
  9954. At the bottom of the graph, we see all the implicit inputs of
  9955. @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
  9956. Now, note that the dependencies of these implicit inputs---that is, the
  9957. @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
  9958. here, for conciseness.
  9959. @item bag
  9960. Similar to @code{bag-emerged}, but this time including all the bootstrap
  9961. dependencies.
  9962. @item bag-with-origins
  9963. Similar to @code{bag}, but also showing origins and their dependencies.
  9964. @item reverse-bag
  9965. This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
  9966. it also takes implicit dependencies into account. For example:
  9967. @example
  9968. guix graph -t reverse-bag dune
  9969. @end example
  9970. @noindent
  9971. ...@: yields the graph of all packages that depend on Dune, directly or
  9972. indirectly. Since Dune is an @emph{implicit} dependency of many packages
  9973. @i{via} @code{dune-build-system}, this shows a large number of packages,
  9974. whereas @code{reverse-package} would show very few if any.
  9975. @item derivation
  9976. This is the most detailed representation: It shows the DAG of
  9977. derivations (@pxref{Derivations}) and plain store items. Compared to
  9978. the above representation, many additional nodes are visible, including
  9979. build scripts, patches, Guile modules, etc.
  9980. For this type of graph, it is also possible to pass a @file{.drv} file
  9981. name instead of a package name, as in:
  9982. @example
  9983. guix graph -t derivation `guix system build -d my-config.scm`
  9984. @end example
  9985. @item module
  9986. This is the graph of @dfn{package modules} (@pxref{Package Modules}).
  9987. For example, the following command shows the graph for the package
  9988. module that defines the @code{guile} package:
  9989. @example
  9990. guix graph -t module guile | xdot -
  9991. @end example
  9992. @end table
  9993. All the types above correspond to @emph{build-time dependencies}. The
  9994. following graph type represents the @emph{run-time dependencies}:
  9995. @table @code
  9996. @item references
  9997. This is the graph of @dfn{references} of a package output, as returned
  9998. by @command{guix gc --references} (@pxref{Invoking guix gc}).
  9999. If the given package output is not available in the store, @command{guix
  10000. graph} attempts to obtain dependency information from substitutes.
  10001. Here you can also pass a store file name instead of a package name. For
  10002. example, the command below produces the reference graph of your profile
  10003. (which can be big!):
  10004. @example
  10005. guix graph -t references `readlink -f ~/.guix-profile`
  10006. @end example
  10007. @item referrers
  10008. This is the graph of the @dfn{referrers} of a store item, as returned by
  10009. @command{guix gc --referrers} (@pxref{Invoking guix gc}).
  10010. This relies exclusively on local information from your store. For
  10011. instance, let us suppose that the current Inkscape is available in 10
  10012. profiles on your machine; @command{guix graph -t referrers inkscape}
  10013. will show a graph rooted at Inkscape and with those 10 profiles linked
  10014. to it.
  10015. It can help determine what is preventing a store item from being garbage
  10016. collected.
  10017. @end table
  10018. @cindex shortest path, between packages
  10019. Often, the graph of the package you are interested in does not fit on
  10020. your screen, and anyway all you want to know is @emph{why} that package
  10021. actually depends on some seemingly unrelated package. The
  10022. @option{--path} option instructs @command{guix graph} to display the
  10023. shortest path between two packages (or derivations, or store items,
  10024. etc.):
  10025. @example
  10026. $ guix graph --path emacs libunistring
  10027. emacs@@26.3
  10028. mailutils@@3.9
  10029. libunistring@@0.9.10
  10030. $ guix graph --path -t derivation emacs libunistring
  10031. /gnu/store/@dots{}-emacs-26.3.drv
  10032. /gnu/store/@dots{}-mailutils-3.9.drv
  10033. /gnu/store/@dots{}-libunistring-0.9.10.drv
  10034. $ guix graph --path -t references emacs libunistring
  10035. /gnu/store/@dots{}-emacs-26.3
  10036. /gnu/store/@dots{}-libidn2-2.2.0
  10037. /gnu/store/@dots{}-libunistring-0.9.10
  10038. @end example
  10039. The available options are the following:
  10040. @table @option
  10041. @item --type=@var{type}
  10042. @itemx -t @var{type}
  10043. Produce a graph output of @var{type}, where @var{type} must be one of
  10044. the values listed above.
  10045. @item --list-types
  10046. List the supported graph types.
  10047. @item --backend=@var{backend}
  10048. @itemx -b @var{backend}
  10049. Produce a graph using the selected @var{backend}.
  10050. @item --list-backends
  10051. List the supported graph backends.
  10052. Currently, the available backends are Graphviz and d3.js.
  10053. @item --path
  10054. Display the shortest path between two nodes of the type specified by
  10055. @option{--type}. The example below shows the shortest path between
  10056. @code{libreoffice} and @code{llvm} according to the references of
  10057. @code{libreoffice}:
  10058. @example
  10059. $ guix graph --path -t references libreoffice llvm
  10060. /gnu/store/@dots{}-libreoffice-6.4.2.2
  10061. /gnu/store/@dots{}-libepoxy-1.5.4
  10062. /gnu/store/@dots{}-mesa-19.3.4
  10063. /gnu/store/@dots{}-llvm-9.0.1
  10064. @end example
  10065. @item --expression=@var{expr}
  10066. @itemx -e @var{expr}
  10067. Consider the package @var{expr} evaluates to.
  10068. This is useful to precisely refer to a package, as in this example:
  10069. @example
  10070. guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
  10071. @end example
  10072. @item --system=@var{system}
  10073. @itemx -s @var{system}
  10074. Display the graph for @var{system}---e.g., @code{i686-linux}.
  10075. The package dependency graph is largely architecture-independent, but there
  10076. are some architecture-dependent bits that this option allows you to visualize.
  10077. @item --load-path=@var{directory}
  10078. @itemx -L @var{directory}
  10079. Add @var{directory} to the front of the package module search path
  10080. (@pxref{Package Modules}).
  10081. This allows users to define their own packages and make them visible to
  10082. the command-line tools.
  10083. @end table
  10084. On top of that, @command{guix graph} supports all the usual package
  10085. transformation options (@pxref{Package Transformation Options}). This
  10086. makes it easy to view the effect of a graph-rewriting transformation
  10087. such as @option{--with-input}. For example, the command below outputs
  10088. the graph of @code{git} once @code{openssl} has been replaced by
  10089. @code{libressl} everywhere in the graph:
  10090. @example
  10091. guix graph git --with-input=openssl=libressl
  10092. @end example
  10093. So many possibilities, so much fun!
  10094. @node Invoking guix publish
  10095. @section Invoking @command{guix publish}
  10096. @cindex @command{guix publish}
  10097. The purpose of @command{guix publish} is to enable users to easily share
  10098. their store with others, who can then use it as a substitute server
  10099. (@pxref{Substitutes}).
  10100. When @command{guix publish} runs, it spawns an HTTP server which allows
  10101. anyone with network access to obtain substitutes from it. This means
  10102. that any machine running Guix can also act as if it were a build farm,
  10103. since the HTTP interface is compatible with Cuirass, the software behind
  10104. the @code{@value{SUBSTITUTE-SERVER}} build farm.
  10105. For security, each substitute is signed, allowing recipients to check
  10106. their authenticity and integrity (@pxref{Substitutes}). Because
  10107. @command{guix publish} uses the signing key of the system, which is only
  10108. readable by the system administrator, it must be started as root; the
  10109. @option{--user} option makes it drop root privileges early on.
  10110. The signing key pair must be generated before @command{guix publish} is
  10111. launched, using @command{guix archive --generate-key} (@pxref{Invoking
  10112. guix archive}).
  10113. When the @option{--advertise} option is passed, the server advertises
  10114. its availability on the local network using multicast DNS (mDNS) and DNS
  10115. service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
  10116. guile-avahi, Using Avahi in Guile Scheme Programs}).
  10117. The general syntax is:
  10118. @example
  10119. guix publish @var{options}@dots{}
  10120. @end example
  10121. Running @command{guix publish} without any additional arguments will
  10122. spawn an HTTP server on port 8080:
  10123. @example
  10124. guix publish
  10125. @end example
  10126. Once a publishing server has been authorized, the daemon may download
  10127. substitutes from it. @xref{Getting Substitutes from Other Servers}.
  10128. By default, @command{guix publish} compresses archives on the fly as it
  10129. serves them. This ``on-the-fly'' mode is convenient in that it requires
  10130. no setup and is immediately available. However, when serving lots of
  10131. clients, we recommend using the @option{--cache} option, which enables
  10132. caching of the archives before they are sent to clients---see below for
  10133. details. The @command{guix weather} command provides a handy way to
  10134. check what a server provides (@pxref{Invoking guix weather}).
  10135. As a bonus, @command{guix publish} also serves as a content-addressed
  10136. mirror for source files referenced in @code{origin} records
  10137. (@pxref{origin Reference}). For instance, assuming @command{guix
  10138. publish} is running on @code{example.org}, the following URL returns the
  10139. raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
  10140. (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
  10141. @example
  10142. http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
  10143. @end example
  10144. Obviously, these URLs only work for files that are in the store; in
  10145. other cases, they return 404 (``Not Found'').
  10146. @cindex build logs, publication
  10147. Build logs are available from @code{/log} URLs like:
  10148. @example
  10149. http://example.org/log/gwspk@dots{}-guile-2.2.3
  10150. @end example
  10151. @noindent
  10152. When @command{guix-daemon} is configured to save compressed build logs,
  10153. as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
  10154. URLs return the compressed log as-is, with an appropriate
  10155. @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
  10156. running @command{guix-daemon} with @option{--log-compression=gzip} since
  10157. Web browsers can automatically decompress it, which is not the case with
  10158. Bzip2 compression.
  10159. The following options are available:
  10160. @table @code
  10161. @item --port=@var{port}
  10162. @itemx -p @var{port}
  10163. Listen for HTTP requests on @var{port}.
  10164. @item --listen=@var{host}
  10165. Listen on the network interface for @var{host}. The default is to
  10166. accept connections from any interface.
  10167. @item --user=@var{user}
  10168. @itemx -u @var{user}
  10169. Change privileges to @var{user} as soon as possible---i.e., once the
  10170. server socket is open and the signing key has been read.
  10171. @item --compression[=@var{method}[:@var{level}]]
  10172. @itemx -C [@var{method}[:@var{level}]]
  10173. Compress data using the given @var{method} and @var{level}. @var{method} is
  10174. one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
  10175. omitted, @code{gzip} is used.
  10176. When @var{level} is zero, disable compression. The range 1 to 9 corresponds
  10177. to different compression levels: 1 is the fastest, and 9 is the best
  10178. (CPU-intensive). The default is 3.
  10179. Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
  10180. small increase in CPU usage; see
  10181. @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
  10182. Web page}. However, @code{lzip} achieves low decompression throughput
  10183. (on the order of 50@tie{}MiB/s on modern hardware), which can be a
  10184. bottleneck for someone who downloads over a fast network connection.
  10185. The compression ratio of @code{zstd} is between that of @code{lzip} and
  10186. that of @code{gzip}; its main advantage is a
  10187. @uref{https://facebook.github.io/zstd/,high decompression speed}.
  10188. Unless @option{--cache} is used, compression occurs on the fly and
  10189. the compressed streams are not
  10190. cached. Thus, to reduce load on the machine that runs @command{guix
  10191. publish}, it may be a good idea to choose a low compression level, to
  10192. run @command{guix publish} behind a caching proxy, or to use
  10193. @option{--cache}. Using @option{--cache} has the advantage that it
  10194. allows @command{guix publish} to add @code{Content-Length} HTTP header
  10195. to its responses.
  10196. This option can be repeated, in which case every substitute gets compressed
  10197. using all the selected methods, and all of them are advertised. This is
  10198. useful when users may not support all the compression methods: they can select
  10199. the one they support.
  10200. @item --cache=@var{directory}
  10201. @itemx -c @var{directory}
  10202. Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
  10203. and only serve archives that are in cache.
  10204. When this option is omitted, archives and meta-data are created
  10205. on-the-fly. This can reduce the available bandwidth, especially when
  10206. compression is enabled, since this may become CPU-bound. Another
  10207. drawback of the default mode is that the length of archives is not known
  10208. in advance, so @command{guix publish} does not add a
  10209. @code{Content-Length} HTTP header to its responses, which in turn
  10210. prevents clients from knowing the amount of data being downloaded.
  10211. Conversely, when @option{--cache} is used, the first request for a store
  10212. item (@i{via} a @code{.narinfo} URL) triggers a
  10213. background process to @dfn{bake} the archive---computing its
  10214. @code{.narinfo} and compressing the archive, if needed. Once the
  10215. archive is cached in @var{directory}, subsequent requests succeed and
  10216. are served directly from the cache, which guarantees that clients get
  10217. the best possible bandwidth.
  10218. That first @code{.narinfo} request nonetheless returns 200, provided the
  10219. requested store item is ``small enough'', below the cache bypass
  10220. threshold---see @option{--cache-bypass-threshold} below. That way,
  10221. clients do not have to wait until the archive is baked. For larger
  10222. store items, the first @code{.narinfo} request returns 404, meaning that
  10223. clients have to wait until the archive is baked.
  10224. The ``baking'' process is performed by worker threads. By default, one
  10225. thread per CPU core is created, but this can be customized. See
  10226. @option{--workers} below.
  10227. When @option{--ttl} is used, cached entries are automatically deleted
  10228. when they have expired.
  10229. @item --workers=@var{N}
  10230. When @option{--cache} is used, request the allocation of @var{N} worker
  10231. threads to ``bake'' archives.
  10232. @item --ttl=@var{ttl}
  10233. Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
  10234. (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
  10235. days, @code{1m} means 1 month, and so on.
  10236. This allows the user's Guix to keep substitute information in cache for
  10237. @var{ttl}. However, note that @code{guix publish} does not itself
  10238. guarantee that the store items it provides will indeed remain available
  10239. for as long as @var{ttl}.
  10240. Additionally, when @option{--cache} is used, cached entries that have
  10241. not been accessed for @var{ttl} and that no longer have a corresponding
  10242. item in the store, may be deleted.
  10243. @item --cache-bypass-threshold=@var{size}
  10244. When used in conjunction with @option{--cache}, store items smaller than
  10245. @var{size} are immediately available, even when they are not yet in
  10246. cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
  10247. for megabytes and so on. The default is @code{10M}.
  10248. ``Cache bypass'' allows you to reduce the publication delay for clients
  10249. at the expense of possibly additional I/O and CPU use on the server
  10250. side: depending on the client access patterns, those store items can end
  10251. up being baked several times until a copy is available in cache.
  10252. Increasing the threshold may be useful for sites that have few users, or
  10253. to guarantee that users get substitutes even for store items that are
  10254. not popular.
  10255. @item --nar-path=@var{path}
  10256. Use @var{path} as the prefix for the URLs of ``nar'' files
  10257. (@pxref{Invoking guix archive, normalized archives}).
  10258. By default, nars are served at a URL such as
  10259. @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
  10260. change the @code{/nar} part to @var{path}.
  10261. @item --public-key=@var{file}
  10262. @itemx --private-key=@var{file}
  10263. Use the specific @var{file}s as the public/private key pair used to sign
  10264. the store items being published.
  10265. The files must correspond to the same key pair (the private key is used
  10266. for signing and the public key is merely advertised in the signature
  10267. metadata). They must contain keys in the canonical s-expression format
  10268. as produced by @command{guix archive --generate-key} (@pxref{Invoking
  10269. guix archive}). By default, @file{/etc/guix/signing-key.pub} and
  10270. @file{/etc/guix/signing-key.sec} are used.
  10271. @item --repl[=@var{port}]
  10272. @itemx -r [@var{port}]
  10273. Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
  10274. Reference Manual}) on @var{port} (37146 by default). This is used
  10275. primarily for debugging a running @command{guix publish} server.
  10276. @end table
  10277. Enabling @command{guix publish} on Guix System is a one-liner: just
  10278. instantiate a @code{guix-publish-service-type} service in the @code{services} field
  10279. of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
  10280. @code{guix-publish-service-type}}).
  10281. If you are instead running Guix on a ``foreign distro'', follow these
  10282. instructions:
  10283. @itemize
  10284. @item
  10285. If your host distro uses the systemd init system:
  10286. @example
  10287. # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
  10288. /etc/systemd/system/
  10289. # systemctl start guix-publish && systemctl enable guix-publish
  10290. @end example
  10291. @item
  10292. If your host distro uses the Upstart init system:
  10293. @example
  10294. # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
  10295. # start guix-publish
  10296. @end example
  10297. @item
  10298. Otherwise, proceed similarly with your distro's init system.
  10299. @end itemize
  10300. @node Invoking guix challenge
  10301. @section Invoking @command{guix challenge}
  10302. @cindex reproducible builds
  10303. @cindex verifiable builds
  10304. @cindex @command{guix challenge}
  10305. @cindex challenge
  10306. Do the binaries provided by this server really correspond to the source
  10307. code it claims to build? Is a package build process deterministic?
  10308. These are the questions the @command{guix challenge} command attempts to
  10309. answer.
  10310. The former is obviously an important question: Before using a substitute
  10311. server (@pxref{Substitutes}), one had better @emph{verify} that it
  10312. provides the right binaries, and thus @emph{challenge} it. The latter
  10313. is what enables the former: If package builds are deterministic, then
  10314. independent builds of the package should yield the exact same result,
  10315. bit for bit; if a server provides a binary different from the one
  10316. obtained locally, it may be either corrupt or malicious.
  10317. We know that the hash that shows up in @file{/gnu/store} file names is
  10318. the hash of all the inputs of the process that built the file or
  10319. directory---compilers, libraries, build scripts,
  10320. etc. (@pxref{Introduction}). Assuming deterministic build processes,
  10321. one store file name should map to exactly one build output.
  10322. @command{guix challenge} checks whether there is, indeed, a single
  10323. mapping by comparing the build outputs of several independent builds of
  10324. any given store item.
  10325. The command output looks like this:
  10326. @smallexample
  10327. $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
  10328. updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
  10329. updating list of substitutes from 'https://guix.example.org'... 100.0%
  10330. /gnu/store/@dots{}-openssl-1.0.2d contents differ:
  10331. local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
  10332. https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
  10333. https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
  10334. differing files:
  10335. /lib/libcrypto.so.1.1
  10336. /lib/libssl.so.1.1
  10337. /gnu/store/@dots{}-git-2.5.0 contents differ:
  10338. local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
  10339. https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
  10340. https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
  10341. differing file:
  10342. /libexec/git-core/git-fsck
  10343. /gnu/store/@dots{}-pius-2.1.1 contents differ:
  10344. local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
  10345. https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
  10346. https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
  10347. differing file:
  10348. /share/man/man1/pius.1.gz
  10349. @dots{}
  10350. 6,406 store items were analyzed:
  10351. - 4,749 (74.1%) were identical
  10352. - 525 (8.2%) differed
  10353. - 1,132 (17.7%) were inconclusive
  10354. @end smallexample
  10355. @noindent
  10356. In this example, @command{guix challenge} first scans the store to
  10357. determine the set of locally-built derivations---as opposed to store
  10358. items that were downloaded from a substitute server---and then queries
  10359. all the substitute servers. It then reports those store items for which
  10360. the servers obtained a result different from the local build.
  10361. @cindex non-determinism, in package builds
  10362. As an example, @code{guix.example.org} always gets a different answer.
  10363. Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
  10364. case of Git. This might indicate that the build process of Git is
  10365. non-deterministic, meaning that its output varies as a function of
  10366. various things that Guix does not fully control, in spite of building
  10367. packages in isolated environments (@pxref{Features}). Most common
  10368. sources of non-determinism include the addition of timestamps in build
  10369. results, the inclusion of random numbers, and directory listings sorted
  10370. by inode number. See @uref{https://reproducible-builds.org/docs/}, for
  10371. more information.
  10372. To find out what is wrong with this Git binary, the easiest approach is
  10373. to run:
  10374. @example
  10375. guix challenge git \
  10376. --diff=diffoscope \
  10377. --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
  10378. @end example
  10379. This automatically invokes @command{diffoscope}, which displays detailed
  10380. information about files that differ.
  10381. Alternatively, we can do something along these lines (@pxref{Invoking guix
  10382. archive}):
  10383. @example
  10384. $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
  10385. | lzip -d | guix archive -x /tmp/git
  10386. $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
  10387. @end example
  10388. This command shows the difference between the files resulting from the
  10389. local build, and the files resulting from the build on
  10390. @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
  10391. diffutils, Comparing and Merging Files}). The @command{diff} command
  10392. works great for text files. When binary files differ, a better option
  10393. is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
  10394. visualize differences for all kinds of files.
  10395. Once you have done that work, you can tell whether the differences are due
  10396. to a non-deterministic build process or to a malicious server. We try
  10397. hard to remove sources of non-determinism in packages to make it easier
  10398. to verify substitutes, but of course, this is a process that
  10399. involves not just Guix, but a large part of the free software community.
  10400. In the meantime, @command{guix challenge} is one tool to help address
  10401. the problem.
  10402. If you are writing packages for Guix, you are encouraged to check
  10403. whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
  10404. same build result as you did with:
  10405. @example
  10406. $ guix challenge @var{package}
  10407. @end example
  10408. @noindent
  10409. where @var{package} is a package specification such as
  10410. @code{guile@@2.0} or @code{glibc:debug}.
  10411. The general syntax is:
  10412. @example
  10413. guix challenge @var{options} [@var{packages}@dots{}]
  10414. @end example
  10415. When a difference is found between the hash of a locally-built item and
  10416. that of a server-provided substitute, or among substitutes provided by
  10417. different servers, the command displays it as in the example above and
  10418. its exit code is 2 (other non-zero exit codes denote other kinds of
  10419. errors).
  10420. The one option that matters is:
  10421. @table @code
  10422. @item --substitute-urls=@var{urls}
  10423. Consider @var{urls} the whitespace-separated list of substitute source
  10424. URLs to compare to.
  10425. @item --diff=@var{mode}
  10426. Upon mismatches, show differences according to @var{mode}, one of:
  10427. @table @asis
  10428. @item @code{simple} (the default)
  10429. Show the list of files that differ.
  10430. @item @code{diffoscope}
  10431. @itemx @var{command}
  10432. Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
  10433. two directories whose contents do not match.
  10434. When @var{command} is an absolute file name, run @var{command} instead
  10435. of Diffoscope.
  10436. @item @code{none}
  10437. Do not show further details about the differences.
  10438. @end table
  10439. Thus, unless @option{--diff=none} is passed, @command{guix challenge}
  10440. downloads the store items from the given substitute servers so that it
  10441. can compare them.
  10442. @item --verbose
  10443. @itemx -v
  10444. Show details about matches (identical contents) in addition to
  10445. information about mismatches.
  10446. @end table
  10447. @node Invoking guix copy
  10448. @section Invoking @command{guix copy}
  10449. @cindex copy, of store items, over SSH
  10450. @cindex SSH, copy of store items
  10451. @cindex sharing store items across machines
  10452. @cindex transferring store items across machines
  10453. The @command{guix copy} command copies items from the store of one
  10454. machine to that of another machine over a secure shell (SSH)
  10455. connection@footnote{This command is available only when Guile-SSH was
  10456. found. @xref{Requirements}, for details.}. For example, the following
  10457. command copies the @code{coreutils} package, the user's profile, and all
  10458. their dependencies over to @var{host}, logged in as @var{user}:
  10459. @example
  10460. guix copy --to=@var{user}@@@var{host} \
  10461. coreutils `readlink -f ~/.guix-profile`
  10462. @end example
  10463. If some of the items to be copied are already present on @var{host},
  10464. they are not actually sent.
  10465. The command below retrieves @code{libreoffice} and @code{gimp} from
  10466. @var{host}, assuming they are available there:
  10467. @example
  10468. guix copy --from=@var{host} libreoffice gimp
  10469. @end example
  10470. The SSH connection is established using the Guile-SSH client, which is
  10471. compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
  10472. @file{~/.ssh/config}, and uses the SSH agent for authentication.
  10473. The key used to sign items that are sent must be accepted by the remote
  10474. machine. Likewise, the key used by the remote machine to sign items you
  10475. are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
  10476. own daemon. @xref{Invoking guix archive}, for more information about
  10477. store item authentication.
  10478. The general syntax is:
  10479. @example
  10480. guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
  10481. @end example
  10482. You must always specify one of the following options:
  10483. @table @code
  10484. @item --to=@var{spec}
  10485. @itemx --from=@var{spec}
  10486. Specify the host to send to or receive from. @var{spec} must be an SSH
  10487. spec such as @code{example.org}, @code{charlie@@example.org}, or
  10488. @code{charlie@@example.org:2222}.
  10489. @end table
  10490. The @var{items} can be either package names, such as @code{gimp}, or
  10491. store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
  10492. When specifying the name of a package to send, it is first built if
  10493. needed, unless @option{--dry-run} was specified. Common build options
  10494. are supported (@pxref{Common Build Options}).
  10495. @node Invoking guix container
  10496. @section Invoking @command{guix container}
  10497. @cindex container
  10498. @cindex @command{guix container}
  10499. @quotation Note
  10500. As of version @value{VERSION}, this tool is experimental. The interface
  10501. is subject to radical change in the future.
  10502. @end quotation
  10503. The purpose of @command{guix container} is to manipulate processes
  10504. running within an isolated environment, commonly known as a
  10505. ``container'', typically created by the @command{guix environment}
  10506. (@pxref{Invoking guix environment}) and @command{guix system container}
  10507. (@pxref{Invoking guix system}) commands.
  10508. The general syntax is:
  10509. @example
  10510. guix container @var{action} @var{options}@dots{}
  10511. @end example
  10512. @var{action} specifies the operation to perform with a container, and
  10513. @var{options} specifies the context-specific arguments for the action.
  10514. The following actions are available:
  10515. @table @code
  10516. @item exec
  10517. Execute a command within the context of a running container.
  10518. The syntax is:
  10519. @example
  10520. guix container exec @var{pid} @var{program} @var{arguments}@dots{}
  10521. @end example
  10522. @var{pid} specifies the process ID of the running container.
  10523. @var{program} specifies an executable file name within the root file
  10524. system of the container. @var{arguments} are the additional options that
  10525. will be passed to @var{program}.
  10526. The following command launches an interactive login shell inside a
  10527. Guix system container, started by @command{guix system container}, and whose
  10528. process ID is 9001:
  10529. @example
  10530. guix container exec 9001 /run/current-system/profile/bin/bash --login
  10531. @end example
  10532. Note that the @var{pid} cannot be the parent process of a container. It
  10533. must be PID 1 of the container or one of its child processes.
  10534. @end table
  10535. @node Invoking guix weather
  10536. @section Invoking @command{guix weather}
  10537. Occasionally you're grumpy because substitutes are lacking and you end
  10538. up building packages by yourself (@pxref{Substitutes}). The
  10539. @command{guix weather} command reports on substitute availability on the
  10540. specified servers so you can have an idea of whether you'll be grumpy
  10541. today. It can sometimes be useful info as a user, but it is primarily
  10542. useful to people running @command{guix publish} (@pxref{Invoking guix
  10543. publish}).
  10544. @cindex statistics, for substitutes
  10545. @cindex availability of substitutes
  10546. @cindex substitute availability
  10547. @cindex weather, substitute availability
  10548. Here's a sample run:
  10549. @example
  10550. $ guix weather --substitute-urls=https://guix.example.org
  10551. computing 5,872 package derivations for x86_64-linux...
  10552. looking for 6,128 store items on https://guix.example.org..
  10553. updating list of substitutes from 'https://guix.example.org'... 100.0%
  10554. https://guix.example.org
  10555. 43.4% substitutes available (2,658 out of 6,128)
  10556. 7,032.5 MiB of nars (compressed)
  10557. 19,824.2 MiB on disk (uncompressed)
  10558. 0.030 seconds per request (182.9 seconds in total)
  10559. 33.5 requests per second
  10560. 9.8% (342 out of 3,470) of the missing items are queued
  10561. 867 queued builds
  10562. x86_64-linux: 518 (59.7%)
  10563. i686-linux: 221 (25.5%)
  10564. aarch64-linux: 128 (14.8%)
  10565. build rate: 23.41 builds per hour
  10566. x86_64-linux: 11.16 builds per hour
  10567. i686-linux: 6.03 builds per hour
  10568. aarch64-linux: 6.41 builds per hour
  10569. @end example
  10570. @cindex continuous integration, statistics
  10571. As you can see, it reports the fraction of all the packages for which
  10572. substitutes are available on the server---regardless of whether
  10573. substitutes are enabled, and regardless of whether this server's signing
  10574. key is authorized. It also reports the size of the compressed archives
  10575. (``nars'') provided by the server, the size the corresponding store
  10576. items occupy in the store (assuming deduplication is turned off), and
  10577. the server's throughput. The second part gives continuous integration
  10578. (CI) statistics, if the server supports it. In addition, using the
  10579. @option{--coverage} option, @command{guix weather} can list ``important''
  10580. package substitutes missing on the server (see below).
  10581. To achieve that, @command{guix weather} queries over HTTP(S) meta-data
  10582. (@dfn{narinfos}) for all the relevant store items. Like @command{guix
  10583. challenge}, it ignores signatures on those substitutes, which is
  10584. innocuous since the command only gathers statistics and cannot install
  10585. those substitutes.
  10586. The general syntax is:
  10587. @example
  10588. guix weather @var{options}@dots{} [@var{packages}@dots{}]
  10589. @end example
  10590. When @var{packages} is omitted, @command{guix weather} checks the availability
  10591. of substitutes for @emph{all} the packages, or for those specified with
  10592. @option{--manifest}; otherwise it only considers the specified packages. It
  10593. is also possible to query specific system types with @option{--system}.
  10594. @command{guix weather} exits with a non-zero code when the fraction of
  10595. available substitutes is below 100%.
  10596. The available options are listed below.
  10597. @table @code
  10598. @item --substitute-urls=@var{urls}
  10599. @var{urls} is the space-separated list of substitute server URLs to
  10600. query. When this option is omitted, the default set of substitute
  10601. servers is queried.
  10602. @item --system=@var{system}
  10603. @itemx -s @var{system}
  10604. Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
  10605. option can be repeated, in which case @command{guix weather} will query
  10606. substitutes for several system types.
  10607. @item --manifest=@var{file}
  10608. Instead of querying substitutes for all the packages, only ask for those
  10609. specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
  10610. with the @code{-m} option of @command{guix package} (@pxref{Invoking
  10611. guix package}).
  10612. This option can be repeated several times, in which case the manifests
  10613. are concatenated.
  10614. @item --coverage[=@var{count}]
  10615. @itemx -c [@var{count}]
  10616. Report on substitute coverage for packages: list packages with at least
  10617. @var{count} dependents (zero by default) for which substitutes are
  10618. unavailable. Dependent packages themselves are not listed: if @var{b} depends
  10619. on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
  10620. @var{b} usually lacks substitutes as well. The result looks like this:
  10621. @example
  10622. $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
  10623. computing 8,983 package derivations for x86_64-linux...
  10624. looking for 9,343 store items on @value{SUBSTITUTE-URL}...
  10625. updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
  10626. @value{SUBSTITUTE-URL}
  10627. 64.7% substitutes available (6,047 out of 9,343)
  10628. @dots{}
  10629. 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
  10630. 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
  10631. 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
  10632. 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
  10633. @dots{}
  10634. @end example
  10635. What this example shows is that @code{kcoreaddons} and presumably the 58
  10636. packages that depend on it have no substitutes at
  10637. @code{@value{SUBSTITUTE-SERVER}}; likewise for @code{qgpgme} and the 46
  10638. packages that depend on it.
  10639. If you are a Guix developer, or if you are taking care of this build farm,
  10640. you'll probably want to have a closer look at these packages: they may simply
  10641. fail to build.
  10642. @item --display-missing
  10643. Display the list of store items for which substitutes are missing.
  10644. @end table
  10645. @node Invoking guix processes
  10646. @section Invoking @command{guix processes}
  10647. The @command{guix processes} command can be useful to developers and system
  10648. administrators, especially on multi-user machines and on build farms: it lists
  10649. the current sessions (connections to the daemon), as well as information about
  10650. the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
  10651. started with @option{--listen} specifying a TCP endpoint, are @emph{not}
  10652. listed.}. Here's an example of the information it returns:
  10653. @example
  10654. $ sudo guix processes
  10655. SessionPID: 19002
  10656. ClientPID: 19090
  10657. ClientCommand: guix environment --ad-hoc python
  10658. SessionPID: 19402
  10659. ClientPID: 19367
  10660. ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
  10661. SessionPID: 19444
  10662. ClientPID: 19419
  10663. ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
  10664. LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
  10665. LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
  10666. LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
  10667. ChildPID: 20495
  10668. ChildCommand: guix offload x86_64-linux 7200 1 28800
  10669. ChildPID: 27733
  10670. ChildCommand: guix offload x86_64-linux 7200 1 28800
  10671. ChildPID: 27793
  10672. ChildCommand: guix offload x86_64-linux 7200 1 28800
  10673. @end example
  10674. In this example we see that @command{guix-daemon} has three clients:
  10675. @command{guix environment}, @command{guix publish}, and the Cuirass continuous
  10676. integration tool; their process identifier (PID) is given by the
  10677. @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
  10678. @command{guix-daemon} sub-process of this particular session.
  10679. The @code{LockHeld} fields show which store items are currently locked
  10680. by this session, which corresponds to store items being built or
  10681. substituted (the @code{LockHeld} field is not displayed when
  10682. @command{guix processes} is not running as root). Last, by looking at
  10683. the @code{ChildPID} and @code{ChildCommand} fields, we understand that
  10684. these three builds are being offloaded (@pxref{Daemon Offload Setup}).
  10685. The output is in Recutils format so we can use the handy @command{recsel}
  10686. command to select sessions of interest (@pxref{Selection Expressions,,,
  10687. recutils, GNU recutils manual}). As an example, the command shows the command
  10688. line and PID of the client that triggered the build of a Perl package:
  10689. @example
  10690. $ sudo guix processes | \
  10691. recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
  10692. ClientPID: 19419
  10693. ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
  10694. @end example
  10695. Additional options are listed below.
  10696. @table @code
  10697. @item --format=@var{format}
  10698. @itemx -f @var{format}
  10699. Produce output in the specified @var{format}, one of:
  10700. @table @code
  10701. @item recutils
  10702. The default option. It outputs a set of Session recutils records
  10703. that include each @code{ChildProcess} as a field.
  10704. @item normalized
  10705. Normalize the output records into record sets (@pxref{Record Sets,,,
  10706. recutils, GNU recutils manual}). Normalizing into record sets allows
  10707. joins across record types. The example below lists the PID of each
  10708. @code{ChildProcess} and the associated PID for @code{Session} that
  10709. spawned the @code{ChildProcess} where the @code{Session} was started
  10710. using @command{guix build}.
  10711. @example
  10712. $ guix processes --format=normalized | \
  10713. recsel \
  10714. -j Session \
  10715. -t ChildProcess \
  10716. -p Session.PID,PID \
  10717. -e 'Session.ClientCommand ~ "guix build"'
  10718. PID: 4435
  10719. Session_PID: 4278
  10720. PID: 4554
  10721. Session_PID: 4278
  10722. PID: 4646
  10723. Session_PID: 4278
  10724. @end example
  10725. @end table
  10726. @end table
  10727. @node System Configuration
  10728. @chapter System Configuration
  10729. @cindex system configuration
  10730. Guix System supports a consistent whole-system configuration
  10731. mechanism. By that we mean that all aspects of the global system
  10732. configuration---such as the available system services, timezone and
  10733. locale settings, user accounts---are declared in a single place. Such
  10734. a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
  10735. One of the advantages of putting all the system configuration under the
  10736. control of Guix is that it supports transactional system upgrades, and
  10737. makes it possible to roll back to a previous system instantiation,
  10738. should something go wrong with the new one (@pxref{Features}). Another
  10739. advantage is that it makes it easy to replicate the exact same configuration
  10740. across different machines, or at different points in time, without
  10741. having to resort to additional administration tools layered on top of
  10742. the own tools of the system.
  10743. @c Yes, we're talking of Puppet, Chef, & co. here. ↑
  10744. This section describes this mechanism. First we focus on the system
  10745. administrator's viewpoint---explaining how the system is configured and
  10746. instantiated. Then we show how this mechanism can be extended, for
  10747. instance to support new system services.
  10748. @menu
  10749. * Using the Configuration System:: Customizing your GNU system.
  10750. * operating-system Reference:: Detail of operating-system declarations.
  10751. * File Systems:: Configuring file system mounts.
  10752. * Mapped Devices:: Block device extra processing.
  10753. * User Accounts:: Specifying user accounts.
  10754. * Keyboard Layout:: How the system interprets key strokes.
  10755. * Locales:: Language and cultural convention settings.
  10756. * Services:: Specifying system services.
  10757. * Setuid Programs:: Programs running with root privileges.
  10758. * X.509 Certificates:: Authenticating HTTPS servers.
  10759. * Name Service Switch:: Configuring libc's name service switch.
  10760. * Initial RAM Disk:: Linux-Libre bootstrapping.
  10761. * Bootloader Configuration:: Configuring the boot loader.
  10762. * Invoking guix system:: Instantiating a system configuration.
  10763. * Invoking guix deploy:: Deploying a system configuration to a remote host.
  10764. * Running Guix in a VM:: How to run Guix System in a virtual machine.
  10765. * Defining Services:: Adding new service definitions.
  10766. @end menu
  10767. @node Using the Configuration System
  10768. @section Using the Configuration System
  10769. The operating system is configured by providing an
  10770. @code{operating-system} declaration in a file that can then be passed to
  10771. the @command{guix system} command (@pxref{Invoking guix system}). A
  10772. simple setup, with the default system services, the default Linux-Libre
  10773. kernel, initial RAM disk, and boot loader looks like this:
  10774. @findex operating-system
  10775. @lisp
  10776. @include os-config-bare-bones.texi
  10777. @end lisp
  10778. This example should be self-describing. Some of the fields defined
  10779. above, such as @code{host-name} and @code{bootloader}, are mandatory.
  10780. Others, such as @code{packages} and @code{services}, can be omitted, in
  10781. which case they get a default value.
  10782. Below we discuss the effect of some of the most important fields
  10783. (@pxref{operating-system Reference}, for details about all the available
  10784. fields), and how to @dfn{instantiate} the operating system using
  10785. @command{guix system}.
  10786. @unnumberedsubsec Bootloader
  10787. @cindex legacy boot, on Intel machines
  10788. @cindex BIOS boot, on Intel machines
  10789. @cindex UEFI boot
  10790. @cindex EFI boot
  10791. The @code{bootloader} field describes the method that will be used to boot
  10792. your system. Machines based on Intel processors can boot in ``legacy'' BIOS
  10793. mode, as in the example above. However, more recent machines rely instead on
  10794. the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
  10795. the @code{bootloader} field should contain something along these lines:
  10796. @lisp
  10797. (bootloader-configuration
  10798. (bootloader grub-efi-bootloader)
  10799. (target "/boot/efi"))
  10800. @end lisp
  10801. @xref{Bootloader Configuration}, for more information on the available
  10802. configuration options.
  10803. @unnumberedsubsec Globally-Visible Packages
  10804. @vindex %base-packages
  10805. The @code{packages} field lists packages that will be globally visible
  10806. on the system, for all user accounts---i.e., in every user's @env{PATH}
  10807. environment variable---in addition to the per-user profiles
  10808. (@pxref{Invoking guix package}). The @code{%base-packages} variable
  10809. provides all the tools one would expect for basic user and administrator
  10810. tasks---including the GNU Core Utilities, the GNU Networking Utilities,
  10811. the GNU Zile lightweight text editor, @command{find}, @command{grep},
  10812. etc. The example above adds GNU@tie{}Screen to those,
  10813. taken from the @code{(gnu packages screen)}
  10814. module (@pxref{Package Modules}). The
  10815. @code{(list package output)} syntax can be used to add a specific output
  10816. of a package:
  10817. @lisp
  10818. (use-modules (gnu packages))
  10819. (use-modules (gnu packages dns))
  10820. (operating-system
  10821. ;; ...
  10822. (packages (cons (list bind "utils")
  10823. %base-packages)))
  10824. @end lisp
  10825. @findex specification->package
  10826. Referring to packages by variable name, like @code{bind} above, has
  10827. the advantage of being unambiguous; it also allows typos and such to be
  10828. diagnosed right away as ``unbound variables''. The downside is that one
  10829. needs to know which module defines which package, and to augment the
  10830. @code{use-package-modules} line accordingly. To avoid that, one can use
  10831. the @code{specification->package} procedure of the @code{(gnu packages)}
  10832. module, which returns the best package for a given name or name and
  10833. version:
  10834. @lisp
  10835. (use-modules (gnu packages))
  10836. (operating-system
  10837. ;; ...
  10838. (packages (append (map specification->package
  10839. '("tcpdump" "htop" "gnupg@@2.0"))
  10840. %base-packages)))
  10841. @end lisp
  10842. @unnumberedsubsec System Services
  10843. @cindex services
  10844. @vindex %base-services
  10845. The @code{services} field lists @dfn{system services} to be made
  10846. available when the system starts (@pxref{Services}).
  10847. The @code{operating-system} declaration above specifies that, in
  10848. addition to the basic services, we want the OpenSSH secure shell
  10849. daemon listening on port 2222 (@pxref{Networking Services,
  10850. @code{openssh-service-type}}). Under the hood,
  10851. @code{openssh-service-type} arranges so that @command{sshd} is started with the
  10852. right command-line options, possibly with supporting configuration files
  10853. generated as needed (@pxref{Defining Services}).
  10854. @cindex customization, of services
  10855. @findex modify-services
  10856. Occasionally, instead of using the base services as is, you will want to
  10857. customize them. To do this, use @code{modify-services} (@pxref{Service
  10858. Reference, @code{modify-services}}) to modify the list.
  10859. For example, suppose you want to modify @code{guix-daemon} and Mingetty
  10860. (the console log-in) in the @code{%base-services} list (@pxref{Base
  10861. Services, @code{%base-services}}). To do that, you can write the
  10862. following in your operating system declaration:
  10863. @lisp
  10864. (define %my-services
  10865. ;; My very own list of services.
  10866. (modify-services %base-services
  10867. (guix-service-type config =>
  10868. (guix-configuration
  10869. (inherit config)
  10870. ;; Fetch substitutes from example.org.
  10871. (substitute-urls
  10872. (list "https://example.org/guix"
  10873. "https://ci.guix.gnu.org"))))
  10874. (mingetty-service-type config =>
  10875. (mingetty-configuration
  10876. (inherit config)
  10877. ;; Automatially log in as "guest".
  10878. (auto-login "guest")))))
  10879. (operating-system
  10880. ;; @dots{}
  10881. (services %my-services))
  10882. @end lisp
  10883. This changes the configuration---i.e., the service parameters---of the
  10884. @code{guix-service-type} instance, and that of all the
  10885. @code{mingetty-service-type} instances in the @code{%base-services} list.
  10886. Observe how this is accomplished: first, we arrange for the original
  10887. configuration to be bound to the identifier @code{config} in the
  10888. @var{body}, and then we write the @var{body} so that it evaluates to the
  10889. desired configuration. In particular, notice how we use @code{inherit}
  10890. to create a new configuration which has the same values as the old
  10891. configuration, but with a few modifications.
  10892. @cindex encrypted disk
  10893. The configuration for a typical ``desktop'' usage, with an encrypted
  10894. root partition, the X11 display
  10895. server, GNOME and Xfce (users can choose which of these desktop
  10896. environments to use at the log-in screen by pressing @kbd{F1}), network
  10897. management, power management, and more, would look like this:
  10898. @lisp
  10899. @include os-config-desktop.texi
  10900. @end lisp
  10901. A graphical system with a choice of lightweight window managers
  10902. instead of full-blown desktop environments would look like this:
  10903. @lisp
  10904. @include os-config-lightweight-desktop.texi
  10905. @end lisp
  10906. This example refers to the @file{/boot/efi} file system by its UUID,
  10907. @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
  10908. as returned by the @command{blkid} command.
  10909. @xref{Desktop Services}, for the exact list of services provided by
  10910. @code{%desktop-services}. @xref{X.509 Certificates}, for background
  10911. information about the @code{nss-certs} package that is used here.
  10912. Again, @code{%desktop-services} is just a list of service objects. If
  10913. you want to remove services from there, you can do so using the
  10914. procedures for list filtering (@pxref{SRFI-1 Filtering and
  10915. Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
  10916. following expression returns a list that contains all the services in
  10917. @code{%desktop-services} minus the Avahi service:
  10918. @lisp
  10919. (remove (lambda (service)
  10920. (eq? (service-kind service) avahi-service-type))
  10921. %desktop-services)
  10922. @end lisp
  10923. @unnumberedsubsec Instantiating the System
  10924. Assuming the @code{operating-system} declaration
  10925. is stored in the @file{my-system-config.scm}
  10926. file, the @command{guix system reconfigure my-system-config.scm} command
  10927. instantiates that configuration, and makes it the default GRUB boot
  10928. entry (@pxref{Invoking guix system}).
  10929. The normal way to change the system configuration is by updating this
  10930. file and re-running @command{guix system reconfigure}. One should never
  10931. have to touch files in @file{/etc} or to run commands that modify the
  10932. system state such as @command{useradd} or @command{grub-install}. In
  10933. fact, you must avoid that since that would not only void your warranty
  10934. but also prevent you from rolling back to previous versions of your
  10935. system, should you ever need to.
  10936. @cindex roll-back, of the operating system
  10937. Speaking of roll-back, each time you run @command{guix system
  10938. reconfigure}, a new @dfn{generation} of the system is created---without
  10939. modifying or deleting previous generations. Old system generations get
  10940. an entry in the bootloader boot menu, allowing you to boot them in case
  10941. something went wrong with the latest generation. Reassuring, no? The
  10942. @command{guix system list-generations} command lists the system
  10943. generations available on disk. It is also possible to roll back the
  10944. system via the commands @command{guix system roll-back} and
  10945. @command{guix system switch-generation}.
  10946. Although the @command{guix system reconfigure} command will not modify
  10947. previous generations, you must take care when the current generation is not
  10948. the latest (e.g., after invoking @command{guix system roll-back}), since
  10949. the operation might overwrite a later generation (@pxref{Invoking guix
  10950. system}).
  10951. @unnumberedsubsec The Programming Interface
  10952. At the Scheme level, the bulk of an @code{operating-system} declaration
  10953. is instantiated with the following monadic procedure (@pxref{The Store
  10954. Monad}):
  10955. @deffn {Monadic Procedure} operating-system-derivation os
  10956. Return a derivation that builds @var{os}, an @code{operating-system}
  10957. object (@pxref{Derivations}).
  10958. The output of the derivation is a single directory that refers to all
  10959. the packages, configuration files, and other supporting files needed to
  10960. instantiate @var{os}.
  10961. @end deffn
  10962. This procedure is provided by the @code{(gnu system)} module. Along
  10963. with @code{(gnu services)} (@pxref{Services}), this module contains the
  10964. guts of Guix System. Make sure to visit it!
  10965. @node operating-system Reference
  10966. @section @code{operating-system} Reference
  10967. This section summarizes all the options available in
  10968. @code{operating-system} declarations (@pxref{Using the Configuration
  10969. System}).
  10970. @deftp {Data Type} operating-system
  10971. This is the data type representing an operating system configuration.
  10972. By that, we mean all the global system configuration, not per-user
  10973. configuration (@pxref{Using the Configuration System}).
  10974. @table @asis
  10975. @item @code{kernel} (default: @code{linux-libre})
  10976. The package object of the operating system kernel to
  10977. use@footnote{Currently only the Linux-libre kernel is fully supported.
  10978. Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
  10979. available when building a virtual machine disk image.}.
  10980. @cindex hurd
  10981. @item @code{hurd} (default: @code{#f})
  10982. The package object of the Hurd to be started by the kernel. When this
  10983. field is set, produce a GNU/Hurd operating system. In that case,
  10984. @code{kernel} must also be set to the @code{gnumach} package---the
  10985. microkernel the Hurd runs on.
  10986. @quotation Warning
  10987. This feature is experimental and only supported for disk images.
  10988. @end quotation
  10989. @item @code{kernel-loadable-modules} (default: '())
  10990. A list of objects (usually packages) to collect loadable kernel modules
  10991. from--e.g. @code{(list ddcci-driver-linux)}.
  10992. @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
  10993. List of strings or gexps representing additional arguments to pass on
  10994. the command-line of the kernel---e.g., @code{("console=ttyS0")}.
  10995. @item @code{bootloader}
  10996. The system bootloader configuration object. @xref{Bootloader Configuration}.
  10997. @item @code{label}
  10998. This is the label (a string) as it appears in the bootloader's menu entry.
  10999. The default label includes the kernel name and version.
  11000. @item @code{keyboard-layout} (default: @code{#f})
  11001. This field specifies the keyboard layout to use in the console. It can be
  11002. either @code{#f}, in which case the default keyboard layout is used (usually
  11003. US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
  11004. for more information.
  11005. This keyboard layout is in effect as soon as the kernel has booted. For
  11006. instance, it is the keyboard layout in effect when you type a passphrase if
  11007. your root file system is on a @code{luks-device-mapping} mapped device
  11008. (@pxref{Mapped Devices}).
  11009. @quotation Note
  11010. This does @emph{not} specify the keyboard layout used by the bootloader, nor
  11011. that used by the graphical display server. @xref{Bootloader Configuration},
  11012. for information on how to specify the bootloader's keyboard layout. @xref{X
  11013. Window}, for information on how to specify the keyboard layout used by the X
  11014. Window System.
  11015. @end quotation
  11016. @item @code{initrd-modules} (default: @code{%base-initrd-modules})
  11017. @cindex initrd
  11018. @cindex initial RAM disk
  11019. The list of Linux kernel modules that need to be available in the
  11020. initial RAM disk. @xref{Initial RAM Disk}.
  11021. @item @code{initrd} (default: @code{base-initrd})
  11022. A procedure that returns an initial RAM disk for the Linux
  11023. kernel. This field is provided to support low-level customization and
  11024. should rarely be needed for casual use. @xref{Initial RAM Disk}.
  11025. @item @code{firmware} (default: @code{%base-firmware})
  11026. @cindex firmware
  11027. List of firmware packages loadable by the operating system kernel.
  11028. The default includes firmware needed for Atheros- and Broadcom-based
  11029. WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
  11030. respectively). @xref{Hardware Considerations}, for more info on
  11031. supported hardware.
  11032. @item @code{host-name}
  11033. The host name.
  11034. @item @code{hosts-file}
  11035. @cindex hosts file
  11036. A file-like object (@pxref{G-Expressions, file-like objects}) for use as
  11037. @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
  11038. Reference Manual}). The default is a file with entries for
  11039. @code{localhost} and @var{host-name}.
  11040. @item @code{mapped-devices} (default: @code{'()})
  11041. A list of mapped devices. @xref{Mapped Devices}.
  11042. @item @code{file-systems}
  11043. A list of file systems. @xref{File Systems}.
  11044. @cindex swap devices
  11045. @cindex swap space
  11046. @item @code{swap-devices} (default: @code{'()})
  11047. A list of UUIDs, file system labels, or strings identifying devices or
  11048. files to be used for ``swap
  11049. space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
  11050. Manual}). Here are some examples:
  11051. @table @code
  11052. @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
  11053. Use the swap partition with the given UUID@. You can learn the UUID of a
  11054. Linux swap partition by running @command{swaplabel @var{device}}, where
  11055. @var{device} is the @file{/dev} file name of that partition.
  11056. @item (list (file-system-label "swap"))
  11057. Use the partition with label @code{swap}. Again, the
  11058. @command{swaplabel} command allows you to view and change the label of a
  11059. Linux swap partition.
  11060. @item (list "/swapfile")
  11061. Use the file @file{/swapfile} as swap space.
  11062. @item (list "/dev/sda3" "/dev/sdb2")
  11063. Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
  11064. We recommend referring to swap devices by UUIDs or labels as shown above
  11065. instead.
  11066. @end table
  11067. It is possible to specify a swap file in a file system on a mapped
  11068. device (under @file{/dev/mapper}), provided that the necessary device
  11069. mapping and file system are also specified. @xref{Mapped Devices} and
  11070. @ref{File Systems}.
  11071. @item @code{users} (default: @code{%base-user-accounts})
  11072. @itemx @code{groups} (default: @code{%base-groups})
  11073. List of user accounts and groups. @xref{User Accounts}.
  11074. If the @code{users} list lacks a user account with UID@tie{}0, a
  11075. ``root'' account with UID@tie{}0 is automatically added.
  11076. @item @code{skeletons} (default: @code{(default-skeletons)})
  11077. A list of target file name/file-like object tuples (@pxref{G-Expressions,
  11078. file-like objects}). These are the skeleton files that will be added to
  11079. the home directory of newly-created user accounts.
  11080. For instance, a valid value may look like this:
  11081. @lisp
  11082. `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
  11083. (".guile" ,(plain-file "guile"
  11084. "(use-modules (ice-9 readline))
  11085. (activate-readline)")))
  11086. @end lisp
  11087. @item @code{issue} (default: @code{%default-issue})
  11088. A string denoting the contents of the @file{/etc/issue} file, which is
  11089. displayed when users log in on a text console.
  11090. @item @code{packages} (default: @code{%base-packages})
  11091. A list of packages to be installed in the global profile, which is accessible
  11092. at @file{/run/current-system/profile}. Each element is either a package
  11093. variable or a package/output tuple. Here's a simple example of both:
  11094. @lisp
  11095. (cons* git ; the default "out" output
  11096. (list git "send-email") ; another output of git
  11097. %base-packages) ; the default set
  11098. @end lisp
  11099. The default set includes core utilities and it is good practice to
  11100. install non-core utilities in user profiles (@pxref{Invoking guix
  11101. package}).
  11102. @item @code{timezone}
  11103. A timezone identifying string---e.g., @code{"Europe/Paris"}.
  11104. You can run the @command{tzselect} command to find out which timezone
  11105. string corresponds to your region. Choosing an invalid timezone name
  11106. causes @command{guix system} to fail.
  11107. @item @code{locale} (default: @code{"en_US.utf8"})
  11108. The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
  11109. Library Reference Manual}). @xref{Locales}, for more information.
  11110. @item @code{locale-definitions} (default: @code{%default-locale-definitions})
  11111. The list of locale definitions to be compiled and that may be used at
  11112. run time. @xref{Locales}.
  11113. @item @code{locale-libcs} (default: @code{(list @var{glibc})})
  11114. The list of GNU@tie{}libc packages whose locale data and tools are used
  11115. to build the locale definitions. @xref{Locales}, for compatibility
  11116. considerations that justify this option.
  11117. @item @code{name-service-switch} (default: @code{%default-nss})
  11118. Configuration of the libc name service switch (NSS)---a
  11119. @code{<name-service-switch>} object. @xref{Name Service Switch}, for
  11120. details.
  11121. @item @code{services} (default: @code{%base-services})
  11122. A list of service objects denoting system services. @xref{Services}.
  11123. @cindex essential services
  11124. @item @code{essential-services} (default: ...)
  11125. The list of ``essential services''---i.e., things like instances of
  11126. @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
  11127. Reference}), which are derived from the operating system definition itself.
  11128. As a user you should @emph{never} need to touch this field.
  11129. @item @code{pam-services} (default: @code{(base-pam-services)})
  11130. @cindex PAM
  11131. @cindex pluggable authentication modules
  11132. Linux @dfn{pluggable authentication module} (PAM) services.
  11133. @c FIXME: Add xref to PAM services section.
  11134. @item @code{setuid-programs} (default: @code{%setuid-programs})
  11135. List of string-valued G-expressions denoting setuid programs.
  11136. @xref{Setuid Programs}.
  11137. @item @code{sudoers-file} (default: @code{%sudoers-specification})
  11138. @cindex sudoers file
  11139. The contents of the @file{/etc/sudoers} file as a file-like object
  11140. (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
  11141. This file specifies which users can use the @command{sudo} command, what
  11142. they are allowed to do, and what privileges they may gain. The default
  11143. is that only @code{root} and members of the @code{wheel} group may use
  11144. @code{sudo}.
  11145. @end table
  11146. @deffn {Scheme Syntax} this-operating-system
  11147. When used in the @emph{lexical scope} of an operating system field definition,
  11148. this identifier resolves to the operating system being defined.
  11149. The example below shows how to refer to the operating system being defined in
  11150. the definition of the @code{label} field:
  11151. @lisp
  11152. (use-modules (gnu) (guix))
  11153. (operating-system
  11154. ;; ...
  11155. (label (package-full-name
  11156. (operating-system-kernel this-operating-system))))
  11157. @end lisp
  11158. It is an error to refer to @code{this-operating-system} outside an operating
  11159. system definition.
  11160. @end deffn
  11161. @end deftp
  11162. @node File Systems
  11163. @section File Systems
  11164. The list of file systems to be mounted is specified in the
  11165. @code{file-systems} field of the operating system declaration
  11166. (@pxref{Using the Configuration System}). Each file system is declared
  11167. using the @code{file-system} form, like this:
  11168. @lisp
  11169. (file-system
  11170. (mount-point "/home")
  11171. (device "/dev/sda3")
  11172. (type "ext4"))
  11173. @end lisp
  11174. As usual, some of the fields are mandatory---those shown in the example
  11175. above---while others can be omitted. These are described below.
  11176. @deftp {Data Type} file-system
  11177. Objects of this type represent file systems to be mounted. They
  11178. contain the following members:
  11179. @table @asis
  11180. @item @code{type}
  11181. This is a string specifying the type of the file system---e.g.,
  11182. @code{"ext4"}.
  11183. @item @code{mount-point}
  11184. This designates the place where the file system is to be mounted.
  11185. @item @code{device}
  11186. This names the ``source'' of the file system. It can be one of three
  11187. things: a file system label, a file system UUID, or the name of a
  11188. @file{/dev} node. Labels and UUIDs offer a way to refer to file
  11189. systems without having to hard-code their actual device
  11190. name@footnote{Note that, while it is tempting to use
  11191. @file{/dev/disk/by-uuid} and similar device names to achieve the same
  11192. result, this is not recommended: These special device nodes are created
  11193. by the udev daemon and may be unavailable at the time the device is
  11194. mounted.}.
  11195. @findex file-system-label
  11196. File system labels are created using the @code{file-system-label}
  11197. procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
  11198. plain strings. Here's an example of a file system referred to by its
  11199. label, as shown by the @command{e2label} command:
  11200. @lisp
  11201. (file-system
  11202. (mount-point "/home")
  11203. (type "ext4")
  11204. (device (file-system-label "my-home")))
  11205. @end lisp
  11206. @findex uuid
  11207. UUIDs are converted from their string representation (as shown by the
  11208. @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
  11209. @code{uuid} form expects 16-byte UUIDs as defined in
  11210. @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
  11211. form of UUID used by the ext2 family of file systems and others, but it
  11212. is different from ``UUIDs'' found in FAT file systems, for instance.},
  11213. like this:
  11214. @lisp
  11215. (file-system
  11216. (mount-point "/home")
  11217. (type "ext4")
  11218. (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
  11219. @end lisp
  11220. When the source of a file system is a mapped device (@pxref{Mapped
  11221. Devices}), its @code{device} field @emph{must} refer to the mapped
  11222. device name---e.g., @file{"/dev/mapper/root-partition"}.
  11223. This is required so that
  11224. the system knows that mounting the file system depends on having the
  11225. corresponding device mapping established.
  11226. @item @code{flags} (default: @code{'()})
  11227. This is a list of symbols denoting mount flags. Recognized flags
  11228. include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
  11229. access to special files), @code{no-suid} (ignore setuid and setgid
  11230. bits), @code{no-atime} (do not update file access times),
  11231. @code{strict-atime} (update file access time), @code{lazy-time} (only
  11232. update time on the in-memory version of the file inode), and
  11233. @code{no-exec} (disallow program execution).
  11234. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
  11235. Manual}, for more information on these flags.
  11236. @item @code{options} (default: @code{#f})
  11237. This is either @code{#f}, or a string denoting mount options passed to
  11238. the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
  11239. Library Reference Manual}, for details and run @command{man 8 mount} for
  11240. options for various file systems. Note that the
  11241. @code{file-system-options->alist} and @code{alist->file-system-options}
  11242. procedures from @code{(gnu system file-systems)} can be used to convert
  11243. file system options given as an association list to the string
  11244. representation, and vice-versa.
  11245. @item @code{mount?} (default: @code{#t})
  11246. This value indicates whether to automatically mount the file system when
  11247. the system is brought up. When set to @code{#f}, the file system gets
  11248. an entry in @file{/etc/fstab} (read by the @command{mount} command) but
  11249. is not automatically mounted.
  11250. @item @code{needed-for-boot?} (default: @code{#f})
  11251. This Boolean value indicates whether the file system is needed when
  11252. booting. If that is true, then the file system is mounted when the
  11253. initial RAM disk (initrd) is loaded. This is always the case, for
  11254. instance, for the root file system.
  11255. @item @code{check?} (default: @code{#t})
  11256. This Boolean indicates whether the file system needs to be checked for
  11257. errors before being mounted.
  11258. @item @code{create-mount-point?} (default: @code{#f})
  11259. When true, the mount point is created if it does not exist yet.
  11260. @item @code{mount-may-fail?} (default: @code{#f})
  11261. When true, this indicates that mounting this file system can fail but
  11262. that should not be considered an error. This is useful in unusual
  11263. cases; an example of this is @code{efivarfs}, a file system that can
  11264. only be mounted on EFI/UEFI systems.
  11265. @item @code{dependencies} (default: @code{'()})
  11266. This is a list of @code{<file-system>} or @code{<mapped-device>} objects
  11267. representing file systems that must be mounted or mapped devices that
  11268. must be opened before (and unmounted or closed after) this one.
  11269. As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
  11270. a dependency of @file{/sys/fs/cgroup/cpu} and
  11271. @file{/sys/fs/cgroup/memory}.
  11272. Another example is a file system that depends on a mapped device, for
  11273. example for an encrypted partition (@pxref{Mapped Devices}).
  11274. @end table
  11275. @end deftp
  11276. @deffn {Scheme Procedure} file-system-label @var{str}
  11277. This procedure returns an opaque file system label from @var{str}, a
  11278. string:
  11279. @lisp
  11280. (file-system-label "home")
  11281. @result{} #<file-system-label "home">
  11282. @end lisp
  11283. File system labels are used to refer to file systems by label rather
  11284. than by device name. See above for examples.
  11285. @end deffn
  11286. The @code{(gnu system file-systems)} exports the following useful
  11287. variables.
  11288. @defvr {Scheme Variable} %base-file-systems
  11289. These are essential file systems that are required on normal systems,
  11290. such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
  11291. below). Operating system declarations should always contain at least
  11292. these.
  11293. @end defvr
  11294. @defvr {Scheme Variable} %pseudo-terminal-file-system
  11295. This is the file system to be mounted as @file{/dev/pts}. It supports
  11296. @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
  11297. functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
  11298. Manual}). Pseudo-terminals are used by terminal emulators such as
  11299. @command{xterm}.
  11300. @end defvr
  11301. @defvr {Scheme Variable} %shared-memory-file-system
  11302. This file system is mounted as @file{/dev/shm} and is used to support
  11303. memory sharing across processes (@pxref{Memory-mapped I/O,
  11304. @code{shm_open},, libc, The GNU C Library Reference Manual}).
  11305. @end defvr
  11306. @defvr {Scheme Variable} %immutable-store
  11307. This file system performs a read-only ``bind mount'' of
  11308. @file{/gnu/store}, making it read-only for all the users including
  11309. @code{root}. This prevents against accidental modification by software
  11310. running as @code{root} or by system administrators.
  11311. The daemon itself is still able to write to the store: it remounts it
  11312. read-write in its own ``name space.''
  11313. @end defvr
  11314. @defvr {Scheme Variable} %binary-format-file-system
  11315. The @code{binfmt_misc} file system, which allows handling of arbitrary
  11316. executable file types to be delegated to user space. This requires the
  11317. @code{binfmt.ko} kernel module to be loaded.
  11318. @end defvr
  11319. @defvr {Scheme Variable} %fuse-control-file-system
  11320. The @code{fusectl} file system, which allows unprivileged users to mount
  11321. and unmount user-space FUSE file systems. This requires the
  11322. @code{fuse.ko} kernel module to be loaded.
  11323. @end defvr
  11324. The @code{(gnu system uuid)} module provides tools to deal with file
  11325. system ``unique identifiers'' (UUIDs).
  11326. @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
  11327. Return an opaque UUID (unique identifier) object of the given @var{type}
  11328. (a symbol) by parsing @var{str} (a string):
  11329. @lisp
  11330. (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
  11331. @result{} #<<uuid> type: dce bv: @dots{}>
  11332. (uuid "1234-ABCD" 'fat)
  11333. @result{} #<<uuid> type: fat bv: @dots{}>
  11334. @end lisp
  11335. @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
  11336. @code{ntfs}, or one of the commonly found synonyms for these.
  11337. UUIDs are another way to unambiguously refer to file systems in
  11338. operating system configuration. See the examples above.
  11339. @end deffn
  11340. @node Btrfs file system
  11341. @subsection Btrfs file system
  11342. The Btrfs has special features, such as subvolumes, that merit being
  11343. explained in more details. The following section attempts to cover
  11344. basic as well as complex uses of a Btrfs file system with the Guix
  11345. System.
  11346. In its simplest usage, a Btrfs file system can be described, for
  11347. example, by:
  11348. @lisp
  11349. (file-system
  11350. (mount-point "/home")
  11351. (type "btrfs")
  11352. (device (file-system-label "my-home")))
  11353. @end lisp
  11354. The example below is more complex, as it makes use of a Btrfs
  11355. subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
  11356. @code{my-btrfs-pool}, and is located on an encrypted device (hence the
  11357. dependency on @code{mapped-devices}):
  11358. @lisp
  11359. (file-system
  11360. (device (file-system-label "my-btrfs-pool"))
  11361. (mount-point "/")
  11362. (type "btrfs")
  11363. (options "subvol=rootfs")
  11364. (dependencies mapped-devices))
  11365. @end lisp
  11366. Some bootloaders, for example GRUB, only mount a Btrfs partition at its
  11367. top level during the early boot, and rely on their configuration to
  11368. refer to the correct subvolume path within that top level. The
  11369. bootloaders operating in this way typically produce their configuration
  11370. on a running system where the Btrfs partitions are already mounted and
  11371. where the subvolume information is readily available. As an example,
  11372. @command{grub-mkconfig}, the configuration generator command shipped
  11373. with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
  11374. path of a subvolume.
  11375. The Guix System produces a bootloader configuration using the operating
  11376. system configuration as its sole input; it is therefore necessary to
  11377. extract the subvolume name on which @file{/gnu/store} lives (if any)
  11378. from that operating system configuration. To better illustrate,
  11379. consider a subvolume named 'rootfs' which contains the root file system
  11380. data. In such situation, the GRUB bootloader would only see the top
  11381. level of the root Btrfs partition, e.g.:
  11382. @example
  11383. / (top level)
  11384. ├── rootfs (subvolume directory)
  11385. ├── gnu (normal directory)
  11386. ├── store (normal directory)
  11387. [...]
  11388. @end example
  11389. Thus, the subvolume name must be prepended to the @file{/gnu/store} path
  11390. of the kernel, initrd binaries and any other files referred to in the
  11391. GRUB configuration that must be found during the early boot.
  11392. The next example shows a nested hierarchy of subvolumes and
  11393. directories:
  11394. @example
  11395. / (top level)
  11396. ├── rootfs (subvolume)
  11397. ├── gnu (normal directory)
  11398. ├── store (subvolume)
  11399. [...]
  11400. @end example
  11401. This scenario would work without mounting the 'store' subvolume.
  11402. Mounting 'rootfs' is sufficient, since the subvolume name matches its
  11403. intended mount point in the file system hierarchy. Alternatively, the
  11404. 'store' subvolume could be referred to by setting the @code{subvol}
  11405. option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
  11406. Finally, a more contrived example of nested subvolumes:
  11407. @example
  11408. / (top level)
  11409. ├── root-snapshots (subvolume)
  11410. ├── root-current (subvolume)
  11411. ├── guix-store (subvolume)
  11412. [...]
  11413. @end example
  11414. Here, the 'guix-store' subvolume doesn't match its intended mount point,
  11415. so it is necessary to mount it. The subvolume must be fully specified,
  11416. by passing its file name to the @code{subvol} option. To illustrate,
  11417. the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
  11418. a file system declaration such as:
  11419. @lisp
  11420. (file-system
  11421. (device (file-system-label "btrfs-pool-1"))
  11422. (mount-point "/gnu/store")
  11423. (type "btrfs")
  11424. (options "subvol=root-snapshots/root-current/guix-store,\
  11425. compress-force=zstd,space_cache=v2"))
  11426. @end lisp
  11427. @node Mapped Devices
  11428. @section Mapped Devices
  11429. @cindex device mapping
  11430. @cindex mapped devices
  11431. The Linux kernel has a notion of @dfn{device mapping}: a block device,
  11432. such as a hard disk partition, can be @dfn{mapped} into another device,
  11433. usually in @code{/dev/mapper/},
  11434. with additional processing over the data that flows through
  11435. it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
  11436. concept of a ``mapped device'' and that of a file system: both boil down
  11437. to @emph{translating} input/output operations made on a file to
  11438. operations on its backing store. Thus, the Hurd implements mapped
  11439. devices, like file systems, using the generic @dfn{translator} mechanism
  11440. (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
  11441. typical example is encryption device mapping: all writes to the mapped
  11442. device are encrypted, and all reads are deciphered, transparently.
  11443. Guix extends this notion by considering any device or set of devices that
  11444. are @dfn{transformed} in some way to create a new device; for instance,
  11445. RAID devices are obtained by @dfn{assembling} several other devices, such
  11446. as hard disks or partitions, into a new one that behaves as one partition.
  11447. Mapped devices are declared using the @code{mapped-device} form,
  11448. defined as follows; for examples, see below.
  11449. @deftp {Data Type} mapped-device
  11450. Objects of this type represent device mappings that will be made when
  11451. the system boots up.
  11452. @table @code
  11453. @item source
  11454. This is either a string specifying the name of the block device to be mapped,
  11455. such as @code{"/dev/sda3"}, or a list of such strings when several devices
  11456. need to be assembled for creating a new one. In case of LVM this is a
  11457. string specifying name of the volume group to be mapped.
  11458. @item target
  11459. This string specifies the name of the resulting mapped device. For
  11460. kernel mappers such as encrypted devices of type @code{luks-device-mapping},
  11461. specifying @code{"my-partition"} leads to the creation of
  11462. the @code{"/dev/mapper/my-partition"} device.
  11463. For RAID devices of type @code{raid-device-mapping}, the full device name
  11464. such as @code{"/dev/md0"} needs to be given.
  11465. LVM logical volumes of type @code{lvm-device-mapping} need to
  11466. be specified as @code{"VGNAME-LVNAME"}.
  11467. @item targets
  11468. This list of strings specifies names of the resulting mapped devices in case
  11469. there are several. The format is identical to @var{target}.
  11470. @item type
  11471. This must be a @code{mapped-device-kind} object, which specifies how
  11472. @var{source} is mapped to @var{target}.
  11473. @end table
  11474. @end deftp
  11475. @defvr {Scheme Variable} luks-device-mapping
  11476. This defines LUKS block device encryption using the @command{cryptsetup}
  11477. command from the package with the same name. It relies on the
  11478. @code{dm-crypt} Linux kernel module.
  11479. @end defvr
  11480. @defvr {Scheme Variable} raid-device-mapping
  11481. This defines a RAID device, which is assembled using the @code{mdadm}
  11482. command from the package with the same name. It requires a Linux kernel
  11483. module for the appropriate RAID level to be loaded, such as @code{raid456}
  11484. for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
  11485. @end defvr
  11486. @cindex LVM, logical volume manager
  11487. @defvr {Scheme Variable} lvm-device-mapping
  11488. This defines one or more logical volumes for the Linux
  11489. @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
  11490. The volume group is activated by the @command{vgchange} command from the
  11491. @code{lvm2} package.
  11492. @end defvr
  11493. @cindex disk encryption
  11494. @cindex LUKS
  11495. The following example specifies a mapping from @file{/dev/sda3} to
  11496. @file{/dev/mapper/home} using LUKS---the
  11497. @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
  11498. standard mechanism for disk encryption.
  11499. The @file{/dev/mapper/home}
  11500. device can then be used as the @code{device} of a @code{file-system}
  11501. declaration (@pxref{File Systems}).
  11502. @lisp
  11503. (mapped-device
  11504. (source "/dev/sda3")
  11505. (target "home")
  11506. (type luks-device-mapping))
  11507. @end lisp
  11508. Alternatively, to become independent of device numbering, one may obtain
  11509. the LUKS UUID (@dfn{unique identifier}) of the source device by a
  11510. command like:
  11511. @example
  11512. cryptsetup luksUUID /dev/sda3
  11513. @end example
  11514. and use it as follows:
  11515. @lisp
  11516. (mapped-device
  11517. (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
  11518. (target "home")
  11519. (type luks-device-mapping))
  11520. @end lisp
  11521. @cindex swap encryption
  11522. It is also desirable to encrypt swap space, since swap space may contain
  11523. sensitive data. One way to accomplish that is to use a swap file in a
  11524. file system on a device mapped via LUKS encryption. In this way, the
  11525. swap file is encrypted because the entire device is encrypted.
  11526. @xref{Preparing for Installation,,Disk Partitioning}, for an example.
  11527. A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
  11528. may be declared as follows:
  11529. @lisp
  11530. (mapped-device
  11531. (source (list "/dev/sda1" "/dev/sdb1"))
  11532. (target "/dev/md0")
  11533. (type raid-device-mapping))
  11534. @end lisp
  11535. The @file{/dev/md0} device can then be used as the @code{device} of a
  11536. @code{file-system} declaration (@pxref{File Systems}).
  11537. Note that the RAID level need not be given; it is chosen during the
  11538. initial creation and formatting of the RAID device and is determined
  11539. automatically later.
  11540. LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
  11541. be declared as follows:
  11542. @lisp
  11543. (mapped-device
  11544. (source "vg0")
  11545. (targets (list "vg0-alpha" "vg0-beta"))
  11546. (type lvm-device-mapping))
  11547. @end lisp
  11548. Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
  11549. then be used as the @code{device} of a @code{file-system} declaration
  11550. (@pxref{File Systems}).
  11551. @node User Accounts
  11552. @section User Accounts
  11553. @cindex users
  11554. @cindex accounts
  11555. @cindex user accounts
  11556. User accounts and groups are entirely managed through the
  11557. @code{operating-system} declaration. They are specified with the
  11558. @code{user-account} and @code{user-group} forms:
  11559. @lisp
  11560. (user-account
  11561. (name "alice")
  11562. (group "users")
  11563. (supplementary-groups '("wheel" ;allow use of sudo, etc.
  11564. "audio" ;sound card
  11565. "video" ;video devices such as webcams
  11566. "cdrom")) ;the good ol' CD-ROM
  11567. (comment "Bob's sister"))
  11568. @end lisp
  11569. Here's a user account that uses a different shell and a custom home
  11570. directory (the default would be @file{"/home/bob"}):
  11571. @lisp
  11572. (user-account
  11573. (name "bob")
  11574. (group "users")
  11575. (comment "Alice's bro")
  11576. (shell (file-append zsh "/bin/zsh"))
  11577. (home-directory "/home/robert"))
  11578. @end lisp
  11579. When booting or upon completion of @command{guix system reconfigure},
  11580. the system ensures that only the user accounts and groups specified in
  11581. the @code{operating-system} declaration exist, and with the specified
  11582. properties. Thus, account or group creations or modifications made by
  11583. directly invoking commands such as @command{useradd} are lost upon
  11584. reconfiguration or reboot. This ensures that the system remains exactly
  11585. as declared.
  11586. @deftp {Data Type} user-account
  11587. Objects of this type represent user accounts. The following members may
  11588. be specified:
  11589. @table @asis
  11590. @item @code{name}
  11591. The name of the user account.
  11592. @item @code{group}
  11593. @cindex groups
  11594. This is the name (a string) or identifier (a number) of the user group
  11595. this account belongs to.
  11596. @item @code{supplementary-groups} (default: @code{'()})
  11597. Optionally, this can be defined as a list of group names that this
  11598. account belongs to.
  11599. @item @code{uid} (default: @code{#f})
  11600. This is the user ID for this account (a number), or @code{#f}. In the
  11601. latter case, a number is automatically chosen by the system when the
  11602. account is created.
  11603. @item @code{comment} (default: @code{""})
  11604. A comment about the account, such as the account owner's full name.
  11605. @item @code{home-directory}
  11606. This is the name of the home directory for the account.
  11607. @item @code{create-home-directory?} (default: @code{#t})
  11608. Indicates whether the home directory of this account should be created
  11609. if it does not exist yet.
  11610. @item @code{shell} (default: Bash)
  11611. This is a G-expression denoting the file name of a program to be used as
  11612. the shell (@pxref{G-Expressions}). For example, you would refer to the
  11613. Bash executable like this:
  11614. @lisp
  11615. (file-append bash "/bin/bash")
  11616. @end lisp
  11617. @noindent
  11618. ... and to the Zsh executable like that:
  11619. @lisp
  11620. (file-append zsh "/bin/zsh")
  11621. @end lisp
  11622. @item @code{system?} (default: @code{#f})
  11623. This Boolean value indicates whether the account is a ``system''
  11624. account. System accounts are sometimes treated specially; for instance,
  11625. graphical login managers do not list them.
  11626. @anchor{user-account-password}
  11627. @cindex password, for user accounts
  11628. @item @code{password} (default: @code{#f})
  11629. You would normally leave this field to @code{#f}, initialize user
  11630. passwords as @code{root} with the @command{passwd} command, and then let
  11631. users change it with @command{passwd}. Passwords set with
  11632. @command{passwd} are of course preserved across reboot and
  11633. reconfiguration.
  11634. If you @emph{do} want to set an initial password for an account, then
  11635. this field must contain the encrypted password, as a string. You can use the
  11636. @code{crypt} procedure for this purpose:
  11637. @lisp
  11638. (user-account
  11639. (name "charlie")
  11640. (group "users")
  11641. ;; Specify a SHA-512-hashed initial password.
  11642. (password (crypt "InitialPassword!" "$6$abc")))
  11643. @end lisp
  11644. @quotation Note
  11645. The hash of this initial password will be available in a file in
  11646. @file{/gnu/store}, readable by all the users, so this method must be used with
  11647. care.
  11648. @end quotation
  11649. @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
  11650. more information on password encryption, and @ref{Encryption,,, guile, GNU
  11651. Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
  11652. @end table
  11653. @end deftp
  11654. @cindex groups
  11655. User group declarations are even simpler:
  11656. @lisp
  11657. (user-group (name "students"))
  11658. @end lisp
  11659. @deftp {Data Type} user-group
  11660. This type is for, well, user groups. There are just a few fields:
  11661. @table @asis
  11662. @item @code{name}
  11663. The name of the group.
  11664. @item @code{id} (default: @code{#f})
  11665. The group identifier (a number). If @code{#f}, a new number is
  11666. automatically allocated when the group is created.
  11667. @item @code{system?} (default: @code{#f})
  11668. This Boolean value indicates whether the group is a ``system'' group.
  11669. System groups have low numerical IDs.
  11670. @item @code{password} (default: @code{#f})
  11671. What, user groups can have a password? Well, apparently yes. Unless
  11672. @code{#f}, this field specifies the password of the group.
  11673. @end table
  11674. @end deftp
  11675. For convenience, a variable lists all the basic user groups one may
  11676. expect:
  11677. @defvr {Scheme Variable} %base-groups
  11678. This is the list of basic user groups that users and/or packages expect
  11679. to be present on the system. This includes groups such as ``root'',
  11680. ``wheel'', and ``users'', as well as groups used to control access to
  11681. specific devices such as ``audio'', ``disk'', and ``cdrom''.
  11682. @end defvr
  11683. @defvr {Scheme Variable} %base-user-accounts
  11684. This is the list of basic system accounts that programs may expect to
  11685. find on a GNU/Linux system, such as the ``nobody'' account.
  11686. Note that the ``root'' account is not included here. It is a
  11687. special-case and is automatically added whether or not it is specified.
  11688. @end defvr
  11689. @node Keyboard Layout
  11690. @section Keyboard Layout
  11691. @cindex keyboard layout
  11692. @cindex keymap
  11693. To specify what each key of your keyboard does, you need to tell the operating
  11694. system what @dfn{keyboard layout} you want to use. The default, when nothing
  11695. is specified, is the US English QWERTY layout for 105-key PC keyboards.
  11696. However, German speakers will usually prefer the German QWERTZ layout, French
  11697. speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
  11698. or bépo, and they might even want to further customize the effect of some of
  11699. the keys. This section explains how to get that done.
  11700. @cindex keyboard layout, definition
  11701. There are three components that will want to know about your keyboard layout:
  11702. @itemize
  11703. @item
  11704. The @emph{bootloader} may want to know what keyboard layout you want to use
  11705. (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
  11706. you want, for instance, to make sure that you can type the passphrase of your
  11707. encrypted root partition using the right layout.
  11708. @item
  11709. The @emph{operating system kernel}, Linux, will need that so that the console
  11710. is properly configured (@pxref{operating-system Reference,
  11711. @code{keyboard-layout}}).
  11712. @item
  11713. The @emph{graphical display server}, usually Xorg, also has its own idea of
  11714. the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
  11715. @end itemize
  11716. Guix allows you to configure all three separately but, fortunately, it allows
  11717. you to share the same keyboard layout for all three components.
  11718. @cindex XKB, keyboard layouts
  11719. Keyboard layouts are represented by records created by the
  11720. @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
  11721. the X Keyboard extension (XKB), each layout has four attributes: a name (often
  11722. a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
  11723. optional variant name, an optional keyboard model name, and a possibly empty
  11724. list of additional options. In most cases the layout name is all you care
  11725. about.
  11726. @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
  11727. [#:model] [#:options '()]
  11728. Return a new keyboard layout with the given @var{name} and @var{variant}.
  11729. @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
  11730. string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
  11731. @code{xkeyboard-config} package for valid options.
  11732. @end deffn
  11733. Here are a few examples:
  11734. @lisp
  11735. ;; The German QWERTZ layout. Here we assume a standard
  11736. ;; "pc105" keyboard model.
  11737. (keyboard-layout "de")
  11738. ;; The bépo variant of the French layout.
  11739. (keyboard-layout "fr" "bepo")
  11740. ;; The Catalan layout.
  11741. (keyboard-layout "es" "cat")
  11742. ;; Arabic layout with "Alt-Shift" to switch to US layout.
  11743. (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
  11744. ;; The Latin American Spanish layout. In addition, the
  11745. ;; "Caps Lock" key is used as an additional "Ctrl" key,
  11746. ;; and the "Menu" key is used as a "Compose" key to enter
  11747. ;; accented letters.
  11748. (keyboard-layout "latam"
  11749. #:options '("ctrl:nocaps" "compose:menu"))
  11750. ;; The Russian layout for a ThinkPad keyboard.
  11751. (keyboard-layout "ru" #:model "thinkpad")
  11752. ;; The "US international" layout, which is the US layout plus
  11753. ;; dead keys to enter accented characters. This is for an
  11754. ;; Apple MacBook keyboard.
  11755. (keyboard-layout "us" "intl" #:model "macbook78")
  11756. @end lisp
  11757. See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
  11758. for a complete list of supported layouts, variants, and models.
  11759. @cindex keyboard layout, configuration
  11760. Let's say you want your system to use the Turkish keyboard layout throughout
  11761. your system---bootloader, console, and Xorg. Here's what your system
  11762. configuration would look like:
  11763. @findex set-xorg-configuration
  11764. @lisp
  11765. ;; Using the Turkish layout for the bootloader, the console,
  11766. ;; and for Xorg.
  11767. (operating-system
  11768. ;; ...
  11769. (keyboard-layout (keyboard-layout "tr")) ;for the console
  11770. (bootloader (bootloader-configuration
  11771. (bootloader grub-efi-bootloader)
  11772. (target "/boot/efi")
  11773. (keyboard-layout keyboard-layout))) ;for GRUB
  11774. (services (cons (set-xorg-configuration
  11775. (xorg-configuration ;for Xorg
  11776. (keyboard-layout keyboard-layout)))
  11777. %desktop-services)))
  11778. @end lisp
  11779. In the example above, for GRUB and for Xorg, we just refer to the
  11780. @code{keyboard-layout} field defined above, but we could just as well refer to
  11781. a different layout. The @code{set-xorg-configuration} procedure communicates
  11782. the desired Xorg configuration to the graphical log-in manager, by default
  11783. GDM.
  11784. We've discussed how to specify the @emph{default} keyboard layout of your
  11785. system when it starts, but you can also adjust it at run time:
  11786. @itemize
  11787. @item
  11788. If you're using GNOME, its settings panel has a ``Region & Language'' entry
  11789. where you can select one or more keyboard layouts.
  11790. @item
  11791. Under Xorg, the @command{setxkbmap} command (from the same-named package)
  11792. allows you to change the current layout. For example, this is how you would
  11793. change the layout to US Dvorak:
  11794. @example
  11795. setxkbmap us dvorak
  11796. @end example
  11797. @item
  11798. The @code{loadkeys} command changes the keyboard layout in effect in the Linux
  11799. console. However, note that @code{loadkeys} does @emph{not} use the XKB
  11800. keyboard layout categorization described above. The command below loads the
  11801. French bépo layout:
  11802. @example
  11803. loadkeys fr-bepo
  11804. @end example
  11805. @end itemize
  11806. @node Locales
  11807. @section Locales
  11808. @cindex locale
  11809. A @dfn{locale} defines cultural conventions for a particular language
  11810. and region of the world (@pxref{Locales,,, libc, The GNU C Library
  11811. Reference Manual}). Each locale has a name that typically has the form
  11812. @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
  11813. @code{fr_LU.utf8} designates the locale for the French language, with
  11814. cultural conventions from Luxembourg, and using the UTF-8 encoding.
  11815. @cindex locale definition
  11816. Usually, you will want to specify the default locale for the machine
  11817. using the @code{locale} field of the @code{operating-system} declaration
  11818. (@pxref{operating-system Reference, @code{locale}}).
  11819. The selected locale is automatically added to the @dfn{locale
  11820. definitions} known to the system if needed, with its codeset inferred
  11821. from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
  11822. @code{UTF-8} codeset. Additional locale definitions can be specified in
  11823. the @code{locale-definitions} slot of @code{operating-system}---this is
  11824. useful, for instance, if the codeset could not be inferred from the
  11825. locale name. The default set of locale definitions includes some widely
  11826. used locales, but not all the available locales, in order to save space.
  11827. For instance, to add the North Frisian locale for Germany, the value of
  11828. that field may be:
  11829. @lisp
  11830. (cons (locale-definition
  11831. (name "fy_DE.utf8") (source "fy_DE"))
  11832. %default-locale-definitions)
  11833. @end lisp
  11834. Likewise, to save space, one might want @code{locale-definitions} to
  11835. list only the locales that are actually used, as in:
  11836. @lisp
  11837. (list (locale-definition
  11838. (name "ja_JP.eucjp") (source "ja_JP")
  11839. (charset "EUC-JP")))
  11840. @end lisp
  11841. @vindex LOCPATH
  11842. The compiled locale definitions are available at
  11843. @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
  11844. version, which is the default location where the GNU@tie{}libc provided
  11845. by Guix looks for locale data. This can be overridden using the
  11846. @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
  11847. @env{LOCPATH} and locale packages}).
  11848. The @code{locale-definition} form is provided by the @code{(gnu system
  11849. locale)} module. Details are given below.
  11850. @deftp {Data Type} locale-definition
  11851. This is the data type of a locale definition.
  11852. @table @asis
  11853. @item @code{name}
  11854. The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
  11855. Reference Manual}, for more information on locale names.
  11856. @item @code{source}
  11857. The name of the source for that locale. This is typically the
  11858. @code{@var{language}_@var{territory}} part of the locale name.
  11859. @item @code{charset} (default: @code{"UTF-8"})
  11860. The ``character set'' or ``code set'' for that locale,
  11861. @uref{https://www.iana.org/assignments/character-sets, as defined by
  11862. IANA}.
  11863. @end table
  11864. @end deftp
  11865. @defvr {Scheme Variable} %default-locale-definitions
  11866. A list of commonly used UTF-8 locales, used as the default
  11867. value of the @code{locale-definitions} field of @code{operating-system}
  11868. declarations.
  11869. @cindex locale name
  11870. @cindex normalized codeset in locale names
  11871. These locale definitions use the @dfn{normalized codeset} for the part
  11872. that follows the dot in the name (@pxref{Using gettextized software,
  11873. normalized codeset,, libc, The GNU C Library Reference Manual}). So for
  11874. instance it has @code{uk_UA.utf8} but @emph{not}, say,
  11875. @code{uk_UA.UTF-8}.
  11876. @end defvr
  11877. @subsection Locale Data Compatibility Considerations
  11878. @cindex incompatibility, of locale data
  11879. @code{operating-system} declarations provide a @code{locale-libcs} field
  11880. to specify the GNU@tie{}libc packages that are used to compile locale
  11881. declarations (@pxref{operating-system Reference}). ``Why would I
  11882. care?'', you may ask. Well, it turns out that the binary format of
  11883. locale data is occasionally incompatible from one libc version to
  11884. another.
  11885. @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
  11886. @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
  11887. For instance, a program linked against libc version 2.21 is unable to
  11888. read locale data produced with libc 2.22; worse, that program
  11889. @emph{aborts} instead of simply ignoring the incompatible locale
  11890. data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
  11891. the incompatible locale data, which is already an improvement.}.
  11892. Similarly, a program linked against libc 2.22 can read most, but not
  11893. all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
  11894. data is incompatible); thus calls to @code{setlocale} may fail, but
  11895. programs will not abort.
  11896. The ``problem'' with Guix is that users have a lot of freedom: They can
  11897. choose whether and when to upgrade software in their profiles, and might
  11898. be using a libc version different from the one the system administrator
  11899. used to build the system-wide locale data.
  11900. Fortunately, unprivileged users can also install their own locale data
  11901. and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
  11902. @env{GUIX_LOCPATH} and locale packages}).
  11903. Still, it is best if the system-wide locale data at
  11904. @file{/run/current-system/locale} is built for all the libc versions
  11905. actually in use on the system, so that all the programs can access
  11906. it---this is especially crucial on a multi-user system. To do that, the
  11907. administrator can specify several libc packages in the
  11908. @code{locale-libcs} field of @code{operating-system}:
  11909. @lisp
  11910. (use-package-modules base)
  11911. (operating-system
  11912. ;; @dots{}
  11913. (locale-libcs (list glibc-2.21 (canonical-package glibc))))
  11914. @end lisp
  11915. This example would lead to a system containing locale definitions for
  11916. both libc 2.21 and the current version of libc in
  11917. @file{/run/current-system/locale}.
  11918. @node Services
  11919. @section Services
  11920. @cindex system services
  11921. An important part of preparing an @code{operating-system} declaration is
  11922. listing @dfn{system services} and their configuration (@pxref{Using the
  11923. Configuration System}). System services are typically daemons launched
  11924. when the system boots, or other actions needed at that time---e.g.,
  11925. configuring network access.
  11926. Guix has a broad definition of ``service'' (@pxref{Service
  11927. Composition}), but many services are managed by the GNU@tie{}Shepherd
  11928. (@pxref{Shepherd Services}). On a running system, the @command{herd}
  11929. command allows you to list the available services, show their status,
  11930. start and stop them, or do other specific operations (@pxref{Jump
  11931. Start,,, shepherd, The GNU Shepherd Manual}). For example:
  11932. @example
  11933. # herd status
  11934. @end example
  11935. The above command, run as @code{root}, lists the currently defined
  11936. services. The @command{herd doc} command shows a synopsis of the given
  11937. service and its associated actions:
  11938. @example
  11939. # herd doc nscd
  11940. Run libc's name service cache daemon (nscd).
  11941. # herd doc nscd action invalidate
  11942. invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
  11943. @end example
  11944. The @command{start}, @command{stop}, and @command{restart} sub-commands
  11945. have the effect you would expect. For instance, the commands below stop
  11946. the nscd service and restart the Xorg display server:
  11947. @example
  11948. # herd stop nscd
  11949. Service nscd has been stopped.
  11950. # herd restart xorg-server
  11951. Service xorg-server has been stopped.
  11952. Service xorg-server has been started.
  11953. @end example
  11954. The following sections document the available services, starting with
  11955. the core services, that may be used in an @code{operating-system}
  11956. declaration.
  11957. @menu
  11958. * Base Services:: Essential system services.
  11959. * Scheduled Job Execution:: The mcron service.
  11960. * Log Rotation:: The rottlog service.
  11961. * Networking Services:: Network setup, SSH daemon, etc.
  11962. * Unattended Upgrades:: Automated system upgrades.
  11963. * X Window:: Graphical display.
  11964. * Printing Services:: Local and remote printer support.
  11965. * Desktop Services:: D-Bus and desktop services.
  11966. * Sound Services:: ALSA and Pulseaudio services.
  11967. * Database Services:: SQL databases, key-value stores, etc.
  11968. * Mail Services:: IMAP, POP3, SMTP, and all that.
  11969. * Messaging Services:: Messaging services.
  11970. * Telephony Services:: Telephony services.
  11971. * File-Sharing Services:: File-sharing services.
  11972. * Monitoring Services:: Monitoring services.
  11973. * Kerberos Services:: Kerberos services.
  11974. * LDAP Services:: LDAP services.
  11975. * Web Services:: Web servers.
  11976. * Certificate Services:: TLS certificates via Let's Encrypt.
  11977. * DNS Services:: DNS daemons.
  11978. * VPN Services:: VPN daemons.
  11979. * Network File System:: NFS related services.
  11980. * Continuous Integration:: The Cuirass service.
  11981. * Power Management Services:: Extending battery life.
  11982. * Audio Services:: The MPD.
  11983. * Virtualization Services:: Virtualization services.
  11984. * Version Control Services:: Providing remote access to Git repositories.
  11985. * Game Services:: Game servers.
  11986. * PAM Mount Service:: Service to mount volumes when logging in.
  11987. * Guix Services:: Services relating specifically to Guix.
  11988. * Linux Services:: Services tied to the Linux kernel.
  11989. * Hurd Services:: Services specific for a Hurd System.
  11990. * Miscellaneous Services:: Other services.
  11991. @end menu
  11992. @node Base Services
  11993. @subsection Base Services
  11994. The @code{(gnu services base)} module provides definitions for the basic
  11995. services that one expects from the system. The services exported by
  11996. this module are listed below.
  11997. @defvr {Scheme Variable} %base-services
  11998. This variable contains a list of basic services (@pxref{Service Types
  11999. and Services}, for more information on service objects) one would
  12000. expect from the system: a login service (mingetty) on each tty, syslogd,
  12001. the libc name service cache daemon (nscd), the udev device manager, and
  12002. more.
  12003. This is the default value of the @code{services} field of
  12004. @code{operating-system} declarations. Usually, when customizing a
  12005. system, you will want to append services to @code{%base-services}, like
  12006. this:
  12007. @lisp
  12008. (append (list (service avahi-service-type)
  12009. (service openssh-service-type))
  12010. %base-services)
  12011. @end lisp
  12012. @end defvr
  12013. @defvr {Scheme Variable} special-files-service-type
  12014. This is the service that sets up ``special files'' such as
  12015. @file{/bin/sh}; an instance of it is part of @code{%base-services}.
  12016. The value associated with @code{special-files-service-type} services
  12017. must be a list of tuples where the first element is the ``special file''
  12018. and the second element is its target. By default it is:
  12019. @cindex @file{/bin/sh}
  12020. @cindex @file{sh}, in @file{/bin}
  12021. @lisp
  12022. `(("/bin/sh" ,(file-append bash "/bin/sh")))
  12023. @end lisp
  12024. @cindex @file{/usr/bin/env}
  12025. @cindex @file{env}, in @file{/usr/bin}
  12026. If you want to add, say, @code{/usr/bin/env} to your system, you can
  12027. change it to:
  12028. @lisp
  12029. `(("/bin/sh" ,(file-append bash "/bin/sh"))
  12030. ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
  12031. @end lisp
  12032. Since this is part of @code{%base-services}, you can use
  12033. @code{modify-services} to customize the set of special files
  12034. (@pxref{Service Reference, @code{modify-services}}). But the simple way
  12035. to add a special file is @i{via} the @code{extra-special-file} procedure
  12036. (see below).
  12037. @end defvr
  12038. @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
  12039. Use @var{target} as the ``special file'' @var{file}.
  12040. For example, adding the following lines to the @code{services} field of
  12041. your operating system declaration leads to a @file{/usr/bin/env}
  12042. symlink:
  12043. @lisp
  12044. (extra-special-file "/usr/bin/env"
  12045. (file-append coreutils "/bin/env"))
  12046. @end lisp
  12047. @end deffn
  12048. @deffn {Scheme Procedure} host-name-service @var{name}
  12049. Return a service that sets the host name to @var{name}.
  12050. @end deffn
  12051. @defvr {Scheme Variable} console-font-service-type
  12052. Install the given fonts on the specified ttys (fonts are per
  12053. virtual console on the kernel Linux). The value of this service is a list of
  12054. tty/font pairs. The font can be the name of a font provided by the @code{kbd}
  12055. package or any valid argument to @command{setfont}, as in this example:
  12056. @lisp
  12057. `(("tty1" . "LatGrkCyr-8x16")
  12058. ("tty2" . ,(file-append
  12059. font-tamzen
  12060. "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
  12061. ("tty3" . ,(file-append
  12062. font-terminus
  12063. "/share/consolefonts/ter-132n"))) ; for HDPI
  12064. @end lisp
  12065. @end defvr
  12066. @deffn {Scheme Procedure} login-service @var{config}
  12067. Return a service to run login according to @var{config}, a
  12068. @code{<login-configuration>} object, which specifies the message of the day,
  12069. among other things.
  12070. @end deffn
  12071. @deftp {Data Type} login-configuration
  12072. This is the data type representing the configuration of login.
  12073. @table @asis
  12074. @item @code{motd}
  12075. @cindex message of the day
  12076. A file-like object containing the ``message of the day''.
  12077. @item @code{allow-empty-passwords?} (default: @code{#t})
  12078. Allow empty passwords by default so that first-time users can log in when
  12079. the 'root' account has just been created.
  12080. @end table
  12081. @end deftp
  12082. @deffn {Scheme Procedure} mingetty-service @var{config}
  12083. Return a service to run mingetty according to @var{config}, a
  12084. @code{<mingetty-configuration>} object, which specifies the tty to run, among
  12085. other things.
  12086. @end deffn
  12087. @deftp {Data Type} mingetty-configuration
  12088. This is the data type representing the configuration of Mingetty, which
  12089. provides the default implementation of virtual console log-in.
  12090. @table @asis
  12091. @item @code{tty}
  12092. The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
  12093. @item @code{auto-login} (default: @code{#f})
  12094. When true, this field must be a string denoting the user name under
  12095. which the system automatically logs in. When it is @code{#f}, a
  12096. user name and password must be entered to log in.
  12097. @item @code{login-program} (default: @code{#f})
  12098. This must be either @code{#f}, in which case the default log-in program
  12099. is used (@command{login} from the Shadow tool suite), or a gexp denoting
  12100. the name of the log-in program.
  12101. @item @code{login-pause?} (default: @code{#f})
  12102. When set to @code{#t} in conjunction with @var{auto-login}, the user
  12103. will have to press a key before the log-in shell is launched.
  12104. @item @code{clear-on-logout?} (default: @code{#t})
  12105. When set to @code{#t}, the screen will be cleared after logout.
  12106. @item @code{mingetty} (default: @var{mingetty})
  12107. The Mingetty package to use.
  12108. @end table
  12109. @end deftp
  12110. @deffn {Scheme Procedure} agetty-service @var{config}
  12111. Return a service to run agetty according to @var{config}, an
  12112. @code{<agetty-configuration>} object, which specifies the tty to run,
  12113. among other things.
  12114. @end deffn
  12115. @deftp {Data Type} agetty-configuration
  12116. This is the data type representing the configuration of agetty, which
  12117. implements virtual and serial console log-in. See the @code{agetty(8)}
  12118. man page for more information.
  12119. @table @asis
  12120. @item @code{tty}
  12121. The name of the console this agetty runs on, as a string---e.g.,
  12122. @code{"ttyS0"}. This argument is optional, it will default to
  12123. a reasonable default serial port used by the kernel Linux.
  12124. For this, if there is a value for an option @code{agetty.tty} in the kernel
  12125. command line, agetty will extract the device name of the serial port
  12126. from it and use that.
  12127. If not and if there is a value for an option @code{console} with a tty in
  12128. the Linux command line, agetty will extract the device name of the
  12129. serial port from it and use that.
  12130. In both cases, agetty will leave the other serial device settings
  12131. (baud rate etc.)@: alone---in the hope that Linux pinned them to the
  12132. correct values.
  12133. @item @code{baud-rate} (default: @code{#f})
  12134. A string containing a comma-separated list of one or more baud rates, in
  12135. descending order.
  12136. @item @code{term} (default: @code{#f})
  12137. A string containing the value used for the @env{TERM} environment
  12138. variable.
  12139. @item @code{eight-bits?} (default: @code{#f})
  12140. When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
  12141. disabled.
  12142. @item @code{auto-login} (default: @code{#f})
  12143. When passed a login name, as a string, the specified user will be logged
  12144. in automatically without prompting for their login name or password.
  12145. @item @code{no-reset?} (default: @code{#f})
  12146. When @code{#t}, don't reset terminal cflags (control modes).
  12147. @item @code{host} (default: @code{#f})
  12148. This accepts a string containing the ``login_host'', which will be written
  12149. into the @file{/var/run/utmpx} file.
  12150. @item @code{remote?} (default: @code{#f})
  12151. When set to @code{#t} in conjunction with @var{host}, this will add an
  12152. @code{-r} fakehost option to the command line of the login program
  12153. specified in @var{login-program}.
  12154. @item @code{flow-control?} (default: @code{#f})
  12155. When set to @code{#t}, enable hardware (RTS/CTS) flow control.
  12156. @item @code{no-issue?} (default: @code{#f})
  12157. When set to @code{#t}, the contents of the @file{/etc/issue} file will
  12158. not be displayed before presenting the login prompt.
  12159. @item @code{init-string} (default: @code{#f})
  12160. This accepts a string that will be sent to the tty or modem before
  12161. sending anything else. It can be used to initialize a modem.
  12162. @item @code{no-clear?} (default: @code{#f})
  12163. When set to @code{#t}, agetty will not clear the screen before showing
  12164. the login prompt.
  12165. @item @code{login-program} (default: (file-append shadow "/bin/login"))
  12166. This must be either a gexp denoting the name of a log-in program, or
  12167. unset, in which case the default value is the @command{login} from the
  12168. Shadow tool suite.
  12169. @item @code{local-line} (default: @code{#f})
  12170. Control the CLOCAL line flag. This accepts one of three symbols as
  12171. arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
  12172. the default value chosen by agetty is @code{'auto}.
  12173. @item @code{extract-baud?} (default: @code{#f})
  12174. When set to @code{#t}, instruct agetty to try to extract the baud rate
  12175. from the status messages produced by certain types of modems.
  12176. @item @code{skip-login?} (default: @code{#f})
  12177. When set to @code{#t}, do not prompt the user for a login name. This
  12178. can be used with @var{login-program} field to use non-standard login
  12179. systems.
  12180. @item @code{no-newline?} (default: @code{#f})
  12181. When set to @code{#t}, do not print a newline before printing the
  12182. @file{/etc/issue} file.
  12183. @c Is this dangerous only when used with login-program, or always?
  12184. @item @code{login-options} (default: @code{#f})
  12185. This option accepts a string containing options that are passed to the
  12186. login program. When used with the @var{login-program}, be aware that a
  12187. malicious user could try to enter a login name containing embedded
  12188. options that could be parsed by the login program.
  12189. @item @code{login-pause} (default: @code{#f})
  12190. When set to @code{#t}, wait for any key before showing the login prompt.
  12191. This can be used in conjunction with @var{auto-login} to save memory by
  12192. lazily spawning shells.
  12193. @item @code{chroot} (default: @code{#f})
  12194. Change root to the specified directory. This option accepts a directory
  12195. path as a string.
  12196. @item @code{hangup?} (default: @code{#f})
  12197. Use the Linux system call @code{vhangup} to do a virtual hangup of the
  12198. specified terminal.
  12199. @item @code{keep-baud?} (default: @code{#f})
  12200. When set to @code{#t}, try to keep the existing baud rate. The baud
  12201. rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
  12202. character.
  12203. @item @code{timeout} (default: @code{#f})
  12204. When set to an integer value, terminate if no user name could be read
  12205. within @var{timeout} seconds.
  12206. @item @code{detect-case?} (default: @code{#f})
  12207. When set to @code{#t}, turn on support for detecting an uppercase-only
  12208. terminal. This setting will detect a login name containing only
  12209. uppercase letters as indicating an uppercase-only terminal and turn on
  12210. some upper-to-lower case conversions. Note that this will not support
  12211. Unicode characters.
  12212. @item @code{wait-cr?} (default: @code{#f})
  12213. When set to @code{#t}, wait for the user or modem to send a
  12214. carriage-return or linefeed character before displaying
  12215. @file{/etc/issue} or login prompt. This is typically used with the
  12216. @var{init-string} option.
  12217. @item @code{no-hints?} (default: @code{#f})
  12218. When set to @code{#t}, do not print hints about Num, Caps, and Scroll
  12219. locks.
  12220. @item @code{no-hostname?} (default: @code{#f})
  12221. By default, the hostname is printed. When this option is set to
  12222. @code{#t}, no hostname will be shown at all.
  12223. @item @code{long-hostname?} (default: @code{#f})
  12224. By default, the hostname is only printed until the first dot. When this
  12225. option is set to @code{#t}, the fully qualified hostname by
  12226. @code{gethostname} or @code{getaddrinfo} is shown.
  12227. @item @code{erase-characters} (default: @code{#f})
  12228. This option accepts a string of additional characters that should be
  12229. interpreted as backspace when the user types their login name.
  12230. @item @code{kill-characters} (default: @code{#f})
  12231. This option accepts a string that should be interpreted to mean ``ignore
  12232. all previous characters'' (also called a ``kill'' character) when the user
  12233. types their login name.
  12234. @item @code{chdir} (default: @code{#f})
  12235. This option accepts, as a string, a directory path that will be changed
  12236. to before login.
  12237. @item @code{delay} (default: @code{#f})
  12238. This options accepts, as an integer, the number of seconds to sleep
  12239. before opening the tty and displaying the login prompt.
  12240. @item @code{nice} (default: @code{#f})
  12241. This option accepts, as an integer, the nice value with which to run the
  12242. @command{login} program.
  12243. @item @code{extra-options} (default: @code{'()})
  12244. This option provides an ``escape hatch'' for the user to provide arbitrary
  12245. command-line arguments to @command{agetty} as a list of strings.
  12246. @end table
  12247. @end deftp
  12248. @deffn {Scheme Procedure} kmscon-service-type @var{config}
  12249. Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
  12250. according to @var{config}, a @code{<kmscon-configuration>} object, which
  12251. specifies the tty to run, among other things.
  12252. @end deffn
  12253. @deftp {Data Type} kmscon-configuration
  12254. This is the data type representing the configuration of Kmscon, which
  12255. implements virtual console log-in.
  12256. @table @asis
  12257. @item @code{virtual-terminal}
  12258. The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
  12259. @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
  12260. A gexp denoting the name of the log-in program. The default log-in program is
  12261. @command{login} from the Shadow tool suite.
  12262. @item @code{login-arguments} (default: @code{'("-p")})
  12263. A list of arguments to pass to @command{login}.
  12264. @item @code{auto-login} (default: @code{#f})
  12265. When passed a login name, as a string, the specified user will be logged
  12266. in automatically without prompting for their login name or password.
  12267. @item @code{hardware-acceleration?} (default: #f)
  12268. Whether to use hardware acceleration.
  12269. @item @code{kmscon} (default: @var{kmscon})
  12270. The Kmscon package to use.
  12271. @end table
  12272. @end deftp
  12273. @cindex name service cache daemon
  12274. @cindex nscd
  12275. @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
  12276. [#:name-services '()]
  12277. Return a service that runs the libc name service cache daemon (nscd) with the
  12278. given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
  12279. Service Switch}, for an example.
  12280. For convenience, the Shepherd service for nscd provides the following actions:
  12281. @table @code
  12282. @item invalidate
  12283. @cindex cache invalidation, nscd
  12284. @cindex nscd, cache invalidation
  12285. This invalidate the given cache. For instance, running:
  12286. @example
  12287. herd invalidate nscd hosts
  12288. @end example
  12289. @noindent
  12290. invalidates the host name lookup cache of nscd.
  12291. @item statistics
  12292. Running @command{herd statistics nscd} displays information about nscd usage
  12293. and caches.
  12294. @end table
  12295. @end deffn
  12296. @defvr {Scheme Variable} %nscd-default-configuration
  12297. This is the default @code{<nscd-configuration>} value (see below) used
  12298. by @code{nscd-service}. It uses the caches defined by
  12299. @code{%nscd-default-caches}; see below.
  12300. @end defvr
  12301. @deftp {Data Type} nscd-configuration
  12302. This is the data type representing the name service cache daemon (nscd)
  12303. configuration.
  12304. @table @asis
  12305. @item @code{name-services} (default: @code{'()})
  12306. List of packages denoting @dfn{name services} that must be visible to
  12307. the nscd---e.g., @code{(list @var{nss-mdns})}.
  12308. @item @code{glibc} (default: @var{glibc})
  12309. Package object denoting the GNU C Library providing the @command{nscd}
  12310. command.
  12311. @item @code{log-file} (default: @code{"/var/log/nscd.log"})
  12312. Name of the nscd log file. This is where debugging output goes when
  12313. @code{debug-level} is strictly positive.
  12314. @item @code{debug-level} (default: @code{0})
  12315. Integer denoting the debugging levels. Higher numbers mean that more
  12316. debugging output is logged.
  12317. @item @code{caches} (default: @code{%nscd-default-caches})
  12318. List of @code{<nscd-cache>} objects denoting things to be cached; see
  12319. below.
  12320. @end table
  12321. @end deftp
  12322. @deftp {Data Type} nscd-cache
  12323. Data type representing a cache database of nscd and its parameters.
  12324. @table @asis
  12325. @item @code{database}
  12326. This is a symbol representing the name of the database to be cached.
  12327. Valid values are @code{passwd}, @code{group}, @code{hosts}, and
  12328. @code{services}, which designate the corresponding NSS database
  12329. (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
  12330. @item @code{positive-time-to-live}
  12331. @itemx @code{negative-time-to-live} (default: @code{20})
  12332. A number representing the number of seconds during which a positive or
  12333. negative lookup result remains in cache.
  12334. @item @code{check-files?} (default: @code{#t})
  12335. Whether to check for updates of the files corresponding to
  12336. @var{database}.
  12337. For instance, when @var{database} is @code{hosts}, setting this flag
  12338. instructs nscd to check for updates in @file{/etc/hosts} and to take
  12339. them into account.
  12340. @item @code{persistent?} (default: @code{#t})
  12341. Whether the cache should be stored persistently on disk.
  12342. @item @code{shared?} (default: @code{#t})
  12343. Whether the cache should be shared among users.
  12344. @item @code{max-database-size} (default: 32@tie{}MiB)
  12345. Maximum size in bytes of the database cache.
  12346. @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
  12347. @c settings, so leave them out.
  12348. @end table
  12349. @end deftp
  12350. @defvr {Scheme Variable} %nscd-default-caches
  12351. List of @code{<nscd-cache>} objects used by default by
  12352. @code{nscd-configuration} (see above).
  12353. It enables persistent and aggressive caching of service and host name
  12354. lookups. The latter provides better host name lookup performance,
  12355. resilience in the face of unreliable name servers, and also better
  12356. privacy---often the result of host name lookups is in local cache, so
  12357. external name servers do not even need to be queried.
  12358. @end defvr
  12359. @anchor{syslog-configuration-type}
  12360. @cindex syslog
  12361. @cindex logging
  12362. @deftp {Data Type} syslog-configuration
  12363. This data type represents the configuration of the syslog daemon.
  12364. @table @asis
  12365. @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
  12366. The syslog daemon to use.
  12367. @item @code{config-file} (default: @code{%default-syslog.conf})
  12368. The syslog configuration file to use.
  12369. @end table
  12370. @end deftp
  12371. @anchor{syslog-service}
  12372. @cindex syslog
  12373. @deffn {Scheme Procedure} syslog-service @var{config}
  12374. Return a service that runs a syslog daemon according to @var{config}.
  12375. @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
  12376. information on the configuration file syntax.
  12377. @end deffn
  12378. @defvr {Scheme Variable} guix-service-type
  12379. This is the type of the service that runs the build daemon,
  12380. @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
  12381. @code{guix-configuration} record as described below.
  12382. @end defvr
  12383. @anchor{guix-configuration-type}
  12384. @deftp {Data Type} guix-configuration
  12385. This data type represents the configuration of the Guix build daemon.
  12386. @xref{Invoking guix-daemon}, for more information.
  12387. @table @asis
  12388. @item @code{guix} (default: @var{guix})
  12389. The Guix package to use.
  12390. @item @code{build-group} (default: @code{"guixbuild"})
  12391. Name of the group for build user accounts.
  12392. @item @code{build-accounts} (default: @code{10})
  12393. Number of build user accounts to create.
  12394. @item @code{authorize-key?} (default: @code{#t})
  12395. @cindex substitutes, authorization thereof
  12396. Whether to authorize the substitute keys listed in
  12397. @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
  12398. (@pxref{Substitutes}).
  12399. When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
  12400. changed by invoking @command{guix archive --authorize}. You must
  12401. instead adjust @code{guix-configuration} as you wish and reconfigure the
  12402. system. This ensures that your operating system configuration file is
  12403. self-contained.
  12404. @quotation Note
  12405. When booting or reconfiguring to a system where @code{authorize-key?}
  12406. is true, the existing @file{/etc/guix/acl} file is backed up as
  12407. @file{/etc/guix/acl.bak} if it was determined to be a manually modified
  12408. file. This is to facilitate migration from earlier versions, which
  12409. allowed for in-place modifications to @file{/etc/guix/acl}.
  12410. @end quotation
  12411. @vindex %default-authorized-guix-keys
  12412. @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
  12413. The list of authorized key files for archive imports, as a list of
  12414. string-valued gexps (@pxref{Invoking guix archive}). By default, it
  12415. contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
  12416. See @code{substitute-urls} below for an example on how to change it.
  12417. @item @code{use-substitutes?} (default: @code{#t})
  12418. Whether to use substitutes.
  12419. @item @code{substitute-urls} (default: @code{%default-substitute-urls})
  12420. The list of URLs where to look for substitutes by default.
  12421. Suppose you would like to fetch substitutes from @code{guix.example.org}
  12422. in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
  12423. two things: (1) add @code{guix.example.org} to @code{substitute-urls},
  12424. and (2) authorize its signing key, having done appropriate checks
  12425. (@pxref{Substitute Server Authorization}). The configuration below does
  12426. exactly that:
  12427. @lisp
  12428. (guix-configuration
  12429. (substitute-urls
  12430. (append (list "https://guix.example.org")
  12431. %default-substitute-urls))
  12432. (authorized-keys
  12433. (append (list (local-file "./guix.example.org-key.pub"))
  12434. %default-authorized-guix-keys)))
  12435. @end lisp
  12436. This example assumes that the file @file{./guix.example.org-key.pub}
  12437. contains the public key that @code{guix.example.org} uses to sign
  12438. substitutes.
  12439. @item @code{max-silent-time} (default: @code{0})
  12440. @itemx @code{timeout} (default: @code{0})
  12441. The number of seconds of silence and the number of seconds of activity,
  12442. respectively, after which a build process times out. A value of zero
  12443. disables the timeout.
  12444. @item @code{log-compression} (default: @code{'bzip2})
  12445. The type of compression used for build logs---one of @code{gzip},
  12446. @code{bzip2}, or @code{none}.
  12447. @item @code{discover?} (default: @code{#f})
  12448. Whether to discover substitute servers on the local network using mDNS
  12449. and DNS-SD.
  12450. @item @code{extra-options} (default: @code{'()})
  12451. List of extra command-line options for @command{guix-daemon}.
  12452. @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
  12453. File where @command{guix-daemon}'s standard output and standard error
  12454. are written.
  12455. @cindex HTTP proxy, for @code{guix-daemon}
  12456. @cindex proxy, for @code{guix-daemon} HTTP access
  12457. @item @code{http-proxy} (default: @code{#f})
  12458. The URL of the HTTP and HTTPS proxy used for downloading fixed-output
  12459. derivations and substitutes.
  12460. It is also possible to change the daemon's proxy at run time through the
  12461. @code{set-http-proxy} action, which restarts it:
  12462. @example
  12463. herd set-http-proxy guix-daemon http://localhost:8118
  12464. @end example
  12465. To clear the proxy settings, run:
  12466. @example
  12467. herd set-http-proxy guix-daemon
  12468. @end example
  12469. @item @code{tmpdir} (default: @code{#f})
  12470. A directory path where the @command{guix-daemon} will perform builds.
  12471. @end table
  12472. @end deftp
  12473. @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
  12474. Run @var{udev}, which populates the @file{/dev} directory dynamically.
  12475. udev rules can be provided as a list of files through the @var{rules}
  12476. variable. The procedures @code{udev-rule}, @code{udev-rules-service}
  12477. and @code{file->udev-rule} from @code{(gnu services base)} simplify the
  12478. creation of such rule files.
  12479. The @command{herd rules udev} command, as root, returns the name of the
  12480. directory containing all the active udev rules.
  12481. @end deffn
  12482. @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
  12483. Return a udev-rule file named @var{file-name} containing the rules
  12484. defined by the @var{contents} literal.
  12485. In the following example, a rule for a USB device is defined to be
  12486. stored in the file @file{90-usb-thing.rules}. The rule runs a script
  12487. upon detecting a USB device with a given product identifier.
  12488. @lisp
  12489. (define %example-udev-rule
  12490. (udev-rule
  12491. "90-usb-thing.rules"
  12492. (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
  12493. "ATTR@{product@}==\"Example\", "
  12494. "RUN+=\"/path/to/script\"")))
  12495. @end lisp
  12496. @end deffn
  12497. @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
  12498. [#:groups @var{groups}]
  12499. Return a service that extends @code{udev-service-type } with @var{rules}
  12500. and @code{account-service-type} with @var{groups} as system groups.
  12501. This works by creating a singleton service type
  12502. @code{@var{name}-udev-rules}, of which the returned service is an
  12503. instance.
  12504. Here we show how it can be used to extend @code{udev-service-type} with the
  12505. previously defined rule @code{%example-udev-rule}.
  12506. @lisp
  12507. (operating-system
  12508. ;; @dots{}
  12509. (services
  12510. (cons (udev-rules-service 'usb-thing %example-udev-rule)
  12511. %desktop-services)))
  12512. @end lisp
  12513. @end deffn
  12514. @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
  12515. Return a udev file named @var{file-name} containing the rules defined
  12516. within @var{file}, a file-like object.
  12517. The following example showcases how we can use an existing rule file.
  12518. @lisp
  12519. (use-modules (guix download) ;for url-fetch
  12520. (guix packages) ;for origin
  12521. @dots{})
  12522. (define %android-udev-rules
  12523. (file->udev-rule
  12524. "51-android-udev.rules"
  12525. (let ((version "20170910"))
  12526. (origin
  12527. (method url-fetch)
  12528. (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
  12529. "android-udev-rules/" version "/51-android.rules"))
  12530. (sha256
  12531. (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
  12532. @end lisp
  12533. @end deffn
  12534. Additionally, Guix package definitions can be included in @var{rules} in
  12535. order to extend the udev rules with the definitions found under their
  12536. @file{lib/udev/rules.d} sub-directory. In lieu of the previous
  12537. @var{file->udev-rule} example, we could have used the
  12538. @var{android-udev-rules} package which exists in Guix in the @code{(gnu
  12539. packages android)} module.
  12540. The following example shows how to use the @var{android-udev-rules}
  12541. package so that the Android tool @command{adb} can detect devices
  12542. without root privileges. It also details how to create the
  12543. @code{adbusers} group, which is required for the proper functioning of
  12544. the rules defined within the @code{android-udev-rules} package. To
  12545. create such a group, we must define it both as part of the
  12546. @code{supplementary-groups} of our @code{user-account} declaration, as
  12547. well as in the @var{groups} of the @code{udev-rules-service} procedure.
  12548. @lisp
  12549. (use-modules (gnu packages android) ;for android-udev-rules
  12550. (gnu system shadow) ;for user-group
  12551. @dots{})
  12552. (operating-system
  12553. ;; @dots{}
  12554. (users (cons (user-account
  12555. ;; @dots{}
  12556. (supplementary-groups
  12557. '("adbusers" ;for adb
  12558. "wheel" "netdev" "audio" "video")))))
  12559. ;; @dots{}
  12560. (services
  12561. (cons (udev-rules-service 'android android-udev-rules
  12562. #:groups '("adbusers"))
  12563. %desktop-services)))
  12564. @end lisp
  12565. @defvr {Scheme Variable} urandom-seed-service-type
  12566. Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
  12567. when rebooting. It also tries to seed @file{/dev/urandom} from
  12568. @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
  12569. readable.
  12570. @end defvr
  12571. @defvr {Scheme Variable} %random-seed-file
  12572. This is the name of the file where some random bytes are saved by
  12573. @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
  12574. It defaults to @file{/var/lib/random-seed}.
  12575. @end defvr
  12576. @cindex mouse
  12577. @cindex gpm
  12578. @defvr {Scheme Variable} gpm-service-type
  12579. This is the type of the service that runs GPM, the @dfn{general-purpose
  12580. mouse daemon}, which provides mouse support to the Linux console. GPM
  12581. allows users to use the mouse in the console, notably to select, copy,
  12582. and paste text.
  12583. The value for services of this type must be a @code{gpm-configuration}
  12584. (see below). This service is not part of @code{%base-services}.
  12585. @end defvr
  12586. @deftp {Data Type} gpm-configuration
  12587. Data type representing the configuration of GPM.
  12588. @table @asis
  12589. @item @code{options} (default: @code{%default-gpm-options})
  12590. Command-line options passed to @command{gpm}. The default set of
  12591. options instruct @command{gpm} to listen to mouse events on
  12592. @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
  12593. more information.
  12594. @item @code{gpm} (default: @code{gpm})
  12595. The GPM package to use.
  12596. @end table
  12597. @end deftp
  12598. @anchor{guix-publish-service-type}
  12599. @deffn {Scheme Variable} guix-publish-service-type
  12600. This is the service type for @command{guix publish} (@pxref{Invoking
  12601. guix publish}). Its value must be a @code{guix-publish-configuration}
  12602. object, as described below.
  12603. This assumes that @file{/etc/guix} already contains a signing key pair as
  12604. created by @command{guix archive --generate-key} (@pxref{Invoking guix
  12605. archive}). If that is not the case, the service will fail to start.
  12606. @end deffn
  12607. @deftp {Data Type} guix-publish-configuration
  12608. Data type representing the configuration of the @code{guix publish}
  12609. service.
  12610. @table @asis
  12611. @item @code{guix} (default: @code{guix})
  12612. The Guix package to use.
  12613. @item @code{port} (default: @code{80})
  12614. The TCP port to listen for connections.
  12615. @item @code{host} (default: @code{"localhost"})
  12616. The host (and thus, network interface) to listen to. Use
  12617. @code{"0.0.0.0"} to listen on all the network interfaces.
  12618. @item @code{advertise?} (default: @code{#f})
  12619. When true, advertise the service on the local network @i{via} the DNS-SD
  12620. protocol, using Avahi.
  12621. This allows neighboring Guix devices with discovery on (see
  12622. @code{guix-configuration} above) to discover this @command{guix publish}
  12623. instance and to automatically download substitutes from it.
  12624. @item @code{compression} (default: @code{'(("gzip" 3))})
  12625. This is a list of compression method/level tuple used when compressing
  12626. substitutes. For example, to compress all substitutes with @emph{both} lzip
  12627. at level 7 and gzip at level 9, write:
  12628. @lisp
  12629. '(("lzip" 7) ("gzip" 9))
  12630. @end lisp
  12631. Level 9 achieves the best compression ratio at the expense of increased CPU
  12632. usage, whereas level 1 achieves fast compression. @xref{Invoking guix
  12633. publish}, for more information on the available compression methods and
  12634. the tradeoffs involved.
  12635. An empty list disables compression altogether.
  12636. @item @code{nar-path} (default: @code{"nar"})
  12637. The URL path at which ``nars'' can be fetched. @xref{Invoking guix
  12638. publish, @option{--nar-path}}, for details.
  12639. @item @code{cache} (default: @code{#f})
  12640. When it is @code{#f}, disable caching and instead generate archives on
  12641. demand. Otherwise, this should be the name of a directory---e.g.,
  12642. @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
  12643. archives and meta-data ready to be sent. @xref{Invoking guix publish,
  12644. @option{--cache}}, for more information on the tradeoffs involved.
  12645. @item @code{workers} (default: @code{#f})
  12646. When it is an integer, this is the number of worker threads used for
  12647. caching; when @code{#f}, the number of processors is used.
  12648. @xref{Invoking guix publish, @option{--workers}}, for more information.
  12649. @item @code{cache-bypass-threshold} (default: 10 MiB)
  12650. When @code{cache} is true, this is the maximum size in bytes of a store
  12651. item for which @command{guix publish} may bypass its cache in case of a
  12652. cache miss. @xref{Invoking guix publish,
  12653. @option{--cache-bypass-threshold}}, for more information.
  12654. @item @code{ttl} (default: @code{#f})
  12655. When it is an integer, this denotes the @dfn{time-to-live} in seconds
  12656. of the published archives. @xref{Invoking guix publish, @option{--ttl}},
  12657. for more information.
  12658. @end table
  12659. @end deftp
  12660. @anchor{rngd-service}
  12661. @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
  12662. [#:device "/dev/hwrng"]
  12663. Return a service that runs the @command{rngd} program from @var{rng-tools}
  12664. to add @var{device} to the kernel's entropy pool. The service will fail if
  12665. @var{device} does not exist.
  12666. @end deffn
  12667. @anchor{pam-limits-service}
  12668. @cindex session limits
  12669. @cindex ulimit
  12670. @cindex priority
  12671. @cindex realtime
  12672. @cindex jackd
  12673. @cindex nofile
  12674. @cindex open file descriptors
  12675. @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
  12676. Return a service that installs a configuration file for the
  12677. @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
  12678. @code{pam_limits} module}. The procedure optionally takes a list of
  12679. @code{pam-limits-entry} values, which can be used to specify
  12680. @code{ulimit} limits and @code{nice} priority limits to user sessions.
  12681. The following limits definition sets two hard and soft limits for all
  12682. login sessions of users in the @code{realtime} group:
  12683. @lisp
  12684. (pam-limits-service
  12685. (list
  12686. (pam-limits-entry "@@realtime" 'both 'rtprio 99)
  12687. (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
  12688. @end lisp
  12689. The first entry increases the maximum realtime priority for
  12690. non-privileged processes; the second entry lifts any restriction of the
  12691. maximum address space that can be locked in memory. These settings are
  12692. commonly used for real-time audio systems.
  12693. Another useful example is raising the maximum number of open file
  12694. descriptors that can be used:
  12695. @lisp
  12696. (pam-limits-service
  12697. (list
  12698. (pam-limits-entry "*" 'both 'nofile 100000)))
  12699. @end lisp
  12700. In the above example, the asterisk means the limit should apply to any
  12701. user. It is important to ensure the chosen value doesn't exceed the
  12702. maximum system value visible in the @file{/proc/sys/fs/file-max} file,
  12703. else the users would be prevented from login in. For more information
  12704. about the Pluggable Authentication Module (PAM) limits, refer to the
  12705. @samp{pam_limits} man page from the @code{linux-pam} package.
  12706. @end deffn
  12707. @node Scheduled Job Execution
  12708. @subsection Scheduled Job Execution
  12709. @cindex cron
  12710. @cindex mcron
  12711. @cindex scheduling jobs
  12712. The @code{(gnu services mcron)} module provides an interface to
  12713. GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
  12714. mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
  12715. Unix @command{cron} daemon; the main difference is that it is
  12716. implemented in Guile Scheme, which provides a lot of flexibility when
  12717. specifying the scheduling of jobs and their actions.
  12718. The example below defines an operating system that runs the
  12719. @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
  12720. and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
  12721. well as the @command{mkid} command on behalf of an unprivileged user
  12722. (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
  12723. gexps to introduce job definitions that are passed to mcron
  12724. (@pxref{G-Expressions}).
  12725. @lisp
  12726. (use-modules (guix) (gnu) (gnu services mcron))
  12727. (use-package-modules base idutils)
  12728. (define updatedb-job
  12729. ;; Run 'updatedb' at 3AM every day. Here we write the
  12730. ;; job's action as a Scheme procedure.
  12731. #~(job '(next-hour '(3))
  12732. (lambda ()
  12733. (execl (string-append #$findutils "/bin/updatedb")
  12734. "updatedb"
  12735. "--prunepaths=/tmp /var/tmp /gnu/store"))))
  12736. (define garbage-collector-job
  12737. ;; Collect garbage 5 minutes after midnight every day.
  12738. ;; The job's action is a shell command.
  12739. #~(job "5 0 * * *" ;Vixie cron syntax
  12740. "guix gc -F 1G"))
  12741. (define idutils-job
  12742. ;; Update the index database as user "charlie" at 12:15PM
  12743. ;; and 19:15PM. This runs from the user's home directory.
  12744. #~(job '(next-minute-from (next-hour '(12 19)) '(15))
  12745. (string-append #$idutils "/bin/mkid src")
  12746. #:user "charlie"))
  12747. (operating-system
  12748. ;; @dots{}
  12749. ;; %BASE-SERVICES already includes an instance of
  12750. ;; 'mcron-service-type', which we extend with additional
  12751. ;; jobs using 'simple-service'.
  12752. (services (cons (simple-service 'my-cron-jobs
  12753. mcron-service-type
  12754. (list garbage-collector-job
  12755. updatedb-job
  12756. idutils-job))
  12757. %base-services)))
  12758. @end lisp
  12759. For more complex jobs defined in Scheme where you need control over the top
  12760. level, for instance to introduce a @code{use-modules} form, you can move your
  12761. code to a separate program using the @code{program-file} procedure of the
  12762. @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
  12763. illustrates that.
  12764. @lisp
  12765. (define %battery-alert-job
  12766. ;; Beep when the battery percentage falls below %MIN-LEVEL.
  12767. #~(job
  12768. '(next-minute (range 0 60 1))
  12769. #$(program-file
  12770. "battery-alert.scm"
  12771. (with-imported-modules (source-module-closure
  12772. '((guix build utils)))
  12773. #~(begin
  12774. (use-modules (guix build utils)
  12775. (ice-9 popen)
  12776. (ice-9 regex)
  12777. (ice-9 textual-ports)
  12778. (srfi srfi-2))
  12779. (define %min-level 20)
  12780. (setenv "LC_ALL" "C") ;ensure English output
  12781. (and-let* ((input-pipe (open-pipe*
  12782. OPEN_READ
  12783. #$(file-append acpi "/bin/acpi")))
  12784. (output (get-string-all input-pipe))
  12785. (m (string-match "Discharging, ([0-9]+)%" output))
  12786. (level (string->number (match:substring m 1)))
  12787. ((< level %min-level)))
  12788. (format #t "warning: Battery level is low (~a%)~%" level)
  12789. (invoke #$(file-append beep "/bin/beep") "-r5")))))))
  12790. @end lisp
  12791. @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
  12792. for more information on mcron job specifications. Below is the
  12793. reference of the mcron service.
  12794. On a running system, you can use the @code{schedule} action of the service to
  12795. visualize the mcron jobs that will be executed next:
  12796. @example
  12797. # herd schedule mcron
  12798. @end example
  12799. @noindent
  12800. The example above lists the next five tasks that will be executed, but you can
  12801. also specify the number of tasks to display:
  12802. @example
  12803. # herd schedule mcron 10
  12804. @end example
  12805. @defvr {Scheme Variable} mcron-service-type
  12806. This is the type of the @code{mcron} service, whose value is an
  12807. @code{mcron-configuration} object.
  12808. This service type can be the target of a service extension that provides
  12809. it additional job specifications (@pxref{Service Composition}). In
  12810. other words, it is possible to define services that provide additional
  12811. mcron jobs to run.
  12812. @end defvr
  12813. @deftp {Data Type} mcron-configuration
  12814. Data type representing the configuration of mcron.
  12815. @table @asis
  12816. @item @code{mcron} (default: @var{mcron})
  12817. The mcron package to use.
  12818. @item @code{jobs}
  12819. This is a list of gexps (@pxref{G-Expressions}), where each gexp
  12820. corresponds to an mcron job specification (@pxref{Syntax, mcron job
  12821. specifications,, mcron, GNU@tie{}mcron}).
  12822. @end table
  12823. @end deftp
  12824. @node Log Rotation
  12825. @subsection Log Rotation
  12826. @cindex rottlog
  12827. @cindex log rotation
  12828. @cindex logging
  12829. Log files such as those found in @file{/var/log} tend to grow endlessly,
  12830. so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
  12831. their contents in separate files, possibly compressed. The @code{(gnu
  12832. services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
  12833. log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
  12834. This service is part of @code{%base-services}, and thus enabled by
  12835. default, with the default settings, for commonly encountered log files.
  12836. The example below shows how to extend it with an additional
  12837. @dfn{rotation}, should you need to do that (usually, services that
  12838. produce log files already take care of that):
  12839. @lisp
  12840. (use-modules (guix) (gnu))
  12841. (use-service-modules admin)
  12842. (define my-log-files
  12843. ;; Log files that I want to rotate.
  12844. '("/var/log/something.log" "/var/log/another.log"))
  12845. (operating-system
  12846. ;; @dots{}
  12847. (services (cons (simple-service 'rotate-my-stuff
  12848. rottlog-service-type
  12849. (list (log-rotation
  12850. (frequency 'daily)
  12851. (files my-log-files))))
  12852. %base-services)))
  12853. @end lisp
  12854. @defvr {Scheme Variable} rottlog-service-type
  12855. This is the type of the Rottlog service, whose value is a
  12856. @code{rottlog-configuration} object.
  12857. Other services can extend this one with new @code{log-rotation} objects
  12858. (see below), thereby augmenting the set of files to be rotated.
  12859. This service type can define mcron jobs (@pxref{Scheduled Job
  12860. Execution}) to run the rottlog service.
  12861. @end defvr
  12862. @deftp {Data Type} rottlog-configuration
  12863. Data type representing the configuration of rottlog.
  12864. @table @asis
  12865. @item @code{rottlog} (default: @code{rottlog})
  12866. The Rottlog package to use.
  12867. @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
  12868. The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
  12869. rottlog, GNU Rot[t]log Manual}).
  12870. @item @code{rotations} (default: @code{%default-rotations})
  12871. A list of @code{log-rotation} objects as defined below.
  12872. @item @code{jobs}
  12873. This is a list of gexps where each gexp corresponds to an mcron job
  12874. specification (@pxref{Scheduled Job Execution}).
  12875. @end table
  12876. @end deftp
  12877. @deftp {Data Type} log-rotation
  12878. Data type representing the rotation of a group of log files.
  12879. Taking an example from the Rottlog manual (@pxref{Period Related File
  12880. Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
  12881. defined like this:
  12882. @lisp
  12883. (log-rotation
  12884. (frequency 'daily)
  12885. (files '("/var/log/apache/*"))
  12886. (options '("storedir apache-archives"
  12887. "rotate 6"
  12888. "notifempty"
  12889. "nocompress")))
  12890. @end lisp
  12891. The list of fields is as follows:
  12892. @table @asis
  12893. @item @code{frequency} (default: @code{'weekly})
  12894. The log rotation frequency, a symbol.
  12895. @item @code{files}
  12896. The list of files or file glob patterns to rotate.
  12897. @item @code{options} (default: @code{'()})
  12898. The list of rottlog options for this rotation (@pxref{Configuration
  12899. parameters,,, rottlog, GNU Rot[t]lg Manual}).
  12900. @item @code{post-rotate} (default: @code{#f})
  12901. Either @code{#f} or a gexp to execute once the rotation has completed.
  12902. @end table
  12903. @end deftp
  12904. @defvr {Scheme Variable} %default-rotations
  12905. Specifies weekly rotation of @code{%rotated-files} and of
  12906. @file{/var/log/guix-daemon.log}.
  12907. @end defvr
  12908. @defvr {Scheme Variable} %rotated-files
  12909. The list of syslog-controlled files to be rotated. By default it is:
  12910. @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
  12911. "/var/log/maillog")}.
  12912. @end defvr
  12913. @node Networking Services
  12914. @subsection Networking Services
  12915. The @code{(gnu services networking)} module provides services to configure
  12916. the network interface.
  12917. @cindex DHCP, networking service
  12918. @defvr {Scheme Variable} dhcp-client-service-type
  12919. This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
  12920. Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
  12921. is the DHCP client package to use, @code{isc-dhcp} by default.
  12922. @end defvr
  12923. @deffn {Scheme Procedure} dhcpd-service-type
  12924. This type defines a service that runs a DHCP daemon. To create a
  12925. service of this type, you must supply a @code{<dhcpd-configuration>}.
  12926. For example:
  12927. @lisp
  12928. (service dhcpd-service-type
  12929. (dhcpd-configuration
  12930. (config-file (local-file "my-dhcpd.conf"))
  12931. (interfaces '("enp0s25"))))
  12932. @end lisp
  12933. @end deffn
  12934. @deftp {Data Type} dhcpd-configuration
  12935. @table @asis
  12936. @item @code{package} (default: @code{isc-dhcp})
  12937. The package that provides the DHCP daemon. This package is expected to
  12938. provide the daemon at @file{sbin/dhcpd} relative to its output
  12939. directory. The default package is the
  12940. @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
  12941. @item @code{config-file} (default: @code{#f})
  12942. The configuration file to use. This is required. It will be passed to
  12943. @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
  12944. object (@pxref{G-Expressions, file-like objects}). See @code{man
  12945. dhcpd.conf} for details on the configuration file syntax.
  12946. @item @code{version} (default: @code{"4"})
  12947. The DHCP version to use. The ISC DHCP server supports the values ``4'',
  12948. ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
  12949. options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
  12950. details.
  12951. @item @code{run-directory} (default: @code{"/run/dhcpd"})
  12952. The run directory to use. At service activation time, this directory
  12953. will be created if it does not exist.
  12954. @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
  12955. The PID file to use. This corresponds to the @code{-pf} option of
  12956. @code{dhcpd}. See @code{man dhcpd} for details.
  12957. @item @code{interfaces} (default: @code{'()})
  12958. The names of the network interfaces on which dhcpd should listen for
  12959. broadcasts. If this list is not empty, then its elements (which must be
  12960. strings) will be appended to the @code{dhcpd} invocation when starting
  12961. the daemon. It may not be necessary to explicitly specify any
  12962. interfaces here; see @code{man dhcpd} for details.
  12963. @end table
  12964. @end deftp
  12965. @defvr {Scheme Variable} static-networking-service-type
  12966. This is the type for statically-configured network interfaces.
  12967. @c TODO Document <static-networking> data structures.
  12968. @end defvr
  12969. @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
  12970. [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
  12971. [#:requirement @code{'(udev)}]
  12972. Return a service that starts @var{interface} with address @var{ip}. If
  12973. @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
  12974. it must be a string specifying the default network gateway. @var{requirement}
  12975. can be used to declare a dependency on another service before configuring the
  12976. interface.
  12977. This procedure can be called several times, one for each network
  12978. interface of interest. Behind the scenes what it does is extend
  12979. @code{static-networking-service-type} with additional network interfaces
  12980. to handle.
  12981. For example:
  12982. @lisp
  12983. (static-networking-service "eno1" "192.168.1.82"
  12984. #:gateway "192.168.1.2"
  12985. #:name-servers '("192.168.1.2"))
  12986. @end lisp
  12987. @end deffn
  12988. @cindex wicd
  12989. @cindex wireless
  12990. @cindex WiFi
  12991. @cindex network management
  12992. @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
  12993. Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
  12994. management daemon that aims to simplify wired and wireless networking.
  12995. This service adds the @var{wicd} package to the global profile, providing
  12996. several commands to interact with the daemon and configure networking:
  12997. @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
  12998. and @command{wicd-curses} user interfaces.
  12999. @end deffn
  13000. @cindex ModemManager
  13001. @defvr {Scheme Variable} modem-manager-service-type
  13002. This is the service type for the
  13003. @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
  13004. service. The value for this service type is a
  13005. @code{modem-manager-configuration} record.
  13006. This service is part of @code{%desktop-services} (@pxref{Desktop
  13007. Services}).
  13008. @end defvr
  13009. @deftp {Data Type} modem-manager-configuration
  13010. Data type representing the configuration of ModemManager.
  13011. @table @asis
  13012. @item @code{modem-manager} (default: @code{modem-manager})
  13013. The ModemManager package to use.
  13014. @end table
  13015. @end deftp
  13016. @cindex USB_ModeSwitch
  13017. @cindex Modeswitching
  13018. @defvr {Scheme Variable} usb-modeswitch-service-type
  13019. This is the service type for the
  13020. @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
  13021. service. The value for this service type is
  13022. a @code{usb-modeswitch-configuration} record.
  13023. When plugged in, some USB modems (and other USB devices) initially present
  13024. themselves as a read-only storage medium and not as a modem. They need to be
  13025. @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
  13026. installs udev rules to automatically modeswitch these devices when they are
  13027. plugged in.
  13028. This service is part of @code{%desktop-services} (@pxref{Desktop
  13029. Services}).
  13030. @end defvr
  13031. @deftp {Data Type} usb-modeswitch-configuration
  13032. Data type representing the configuration of USB_ModeSwitch.
  13033. @table @asis
  13034. @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
  13035. The USB_ModeSwitch package providing the binaries for modeswitching.
  13036. @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
  13037. The package providing the device data and udev rules file used by
  13038. USB_ModeSwitch.
  13039. @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
  13040. Which config file to use for the USB_ModeSwitch dispatcher. By default the
  13041. config file shipped with USB_ModeSwitch is used which disables logging to
  13042. @file{/var/log} among other default settings. If set to @code{#f}, no config
  13043. file is used.
  13044. @end table
  13045. @end deftp
  13046. @cindex NetworkManager
  13047. @defvr {Scheme Variable} network-manager-service-type
  13048. This is the service type for the
  13049. @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
  13050. service. The value for this service type is a
  13051. @code{network-manager-configuration} record.
  13052. This service is part of @code{%desktop-services} (@pxref{Desktop
  13053. Services}).
  13054. @end defvr
  13055. @deftp {Data Type} network-manager-configuration
  13056. Data type representing the configuration of NetworkManager.
  13057. @table @asis
  13058. @item @code{network-manager} (default: @code{network-manager})
  13059. The NetworkManager package to use.
  13060. @item @code{dns} (default: @code{"default"})
  13061. Processing mode for DNS, which affects how NetworkManager uses the
  13062. @code{resolv.conf} configuration file.
  13063. @table @samp
  13064. @item default
  13065. NetworkManager will update @code{resolv.conf} to reflect the nameservers
  13066. provided by currently active connections.
  13067. @item dnsmasq
  13068. NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
  13069. @dfn{conditional forwarding} configuration if you are connected to a VPN, and
  13070. then update @code{resolv.conf} to point to the local nameserver.
  13071. With this setting, you can share your network connection. For example when
  13072. you want to share your network connection to another laptop @i{via} an
  13073. Ethernet cable, you can open @command{nm-connection-editor} and configure the
  13074. Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
  13075. and reestablish the connection (or reboot).
  13076. You can also set up a @dfn{host-to-guest connection} to QEMU VMs
  13077. (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
  13078. e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
  13079. browser on your host system, or connect to the VM @i{via} SSH
  13080. (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
  13081. host-to-guest connection, run this command once:
  13082. @example
  13083. nmcli connection add type tun \
  13084. connection.interface-name tap0 \
  13085. tun.mode tap tun.owner $(id -u) \
  13086. ipv4.method shared \
  13087. ipv4.addresses 172.28.112.1/24
  13088. @end example
  13089. Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
  13090. @option{-nic tap,ifname=tap0,script=no,downscript=no} to
  13091. @command{qemu-system-...}.
  13092. @item none
  13093. NetworkManager will not modify @code{resolv.conf}.
  13094. @end table
  13095. @item @code{vpn-plugins} (default: @code{'()})
  13096. This is the list of available plugins for virtual private networks
  13097. (VPNs). An example of this is the @code{network-manager-openvpn}
  13098. package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
  13099. @end table
  13100. @end deftp
  13101. @cindex Connman
  13102. @deffn {Scheme Variable} connman-service-type
  13103. This is the service type to run @url{https://01.org/connman,Connman},
  13104. a network connection manager.
  13105. Its value must be an
  13106. @code{connman-configuration} record as in this example:
  13107. @lisp
  13108. (service connman-service-type
  13109. (connman-configuration
  13110. (disable-vpn? #t)))
  13111. @end lisp
  13112. See below for details about @code{connman-configuration}.
  13113. @end deffn
  13114. @deftp {Data Type} connman-configuration
  13115. Data Type representing the configuration of connman.
  13116. @table @asis
  13117. @item @code{connman} (default: @var{connman})
  13118. The connman package to use.
  13119. @item @code{disable-vpn?} (default: @code{#f})
  13120. When true, disable connman's vpn plugin.
  13121. @end table
  13122. @end deftp
  13123. @cindex WPA Supplicant
  13124. @defvr {Scheme Variable} wpa-supplicant-service-type
  13125. This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
  13126. supplicant}, an authentication daemon required to authenticate against
  13127. encrypted WiFi or ethernet networks.
  13128. @end defvr
  13129. @deftp {Data Type} wpa-supplicant-configuration
  13130. Data type representing the configuration of WPA Supplicant.
  13131. It takes the following parameters:
  13132. @table @asis
  13133. @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
  13134. The WPA Supplicant package to use.
  13135. @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
  13136. List of services that should be started before WPA Supplicant starts.
  13137. @item @code{dbus?} (default: @code{#t})
  13138. Whether to listen for requests on D-Bus.
  13139. @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
  13140. Where to store the PID file.
  13141. @item @code{interface} (default: @code{#f})
  13142. If this is set, it must specify the name of a network interface that
  13143. WPA supplicant will control.
  13144. @item @code{config-file} (default: @code{#f})
  13145. Optional configuration file to use.
  13146. @item @code{extra-options} (default: @code{'()})
  13147. List of additional command-line arguments to pass to the daemon.
  13148. @end table
  13149. @end deftp
  13150. @cindex hostapd service, for Wi-Fi access points
  13151. @cindex Wi-Fi access points, hostapd service
  13152. @defvr {Scheme Variable} hostapd-service-type
  13153. This is the service type to run the @uref{https://w1.fi/hostapd/,
  13154. hostapd} daemon to set up WiFi (IEEE 802.11) access points and
  13155. authentication servers. Its associated value must be a
  13156. @code{hostapd-configuration} as shown below:
  13157. @lisp
  13158. ;; Use wlan1 to run the access point for "My Network".
  13159. (service hostapd-service-type
  13160. (hostapd-configuration
  13161. (interface "wlan1")
  13162. (ssid "My Network")
  13163. (channel 12)))
  13164. @end lisp
  13165. @end defvr
  13166. @deftp {Data Type} hostapd-configuration
  13167. This data type represents the configuration of the hostapd service, with
  13168. the following fields:
  13169. @table @asis
  13170. @item @code{package} (default: @code{hostapd})
  13171. The hostapd package to use.
  13172. @item @code{interface} (default: @code{"wlan0"})
  13173. The network interface to run the WiFi access point.
  13174. @item @code{ssid}
  13175. The SSID (@dfn{service set identifier}), a string that identifies this
  13176. network.
  13177. @item @code{broadcast-ssid?} (default: @code{#t})
  13178. Whether to broadcast this SSID.
  13179. @item @code{channel} (default: @code{1})
  13180. The WiFi channel to use.
  13181. @item @code{driver} (default: @code{"nl80211"})
  13182. The driver interface type. @code{"nl80211"} is used with all Linux
  13183. mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
  13184. RADIUS server that does # not control any wireless/wired driver.
  13185. @item @code{extra-settings} (default: @code{""})
  13186. Extra settings to append as-is to the hostapd configuration file. See
  13187. @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
  13188. configuration file reference.
  13189. @end table
  13190. @end deftp
  13191. @defvr {Scheme Variable} simulated-wifi-service-type
  13192. This is the type of a service to simulate WiFi networking, which can be
  13193. useful in virtual machines for testing purposes. The service loads the
  13194. Linux kernel
  13195. @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
  13196. @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
  13197. network that can be seen on @code{wlan0}, by default.
  13198. The service's value is a @code{hostapd-configuration} record.
  13199. @end defvr
  13200. @cindex iptables
  13201. @defvr {Scheme Variable} iptables-service-type
  13202. This is the service type to set up an iptables configuration. iptables is a
  13203. packet filtering framework supported by the Linux kernel. This service
  13204. supports configuring iptables for both IPv4 and IPv6. A simple example
  13205. configuration rejecting all incoming connections except those to the ssh port
  13206. 22 is shown below.
  13207. @lisp
  13208. (service iptables-service-type
  13209. (iptables-configuration
  13210. (ipv4-rules (plain-file "iptables.rules" "*filter
  13211. :INPUT ACCEPT
  13212. :FORWARD ACCEPT
  13213. :OUTPUT ACCEPT
  13214. -A INPUT -p tcp --dport 22 -j ACCEPT
  13215. -A INPUT -j REJECT --reject-with icmp-port-unreachable
  13216. COMMIT
  13217. "))
  13218. (ipv6-rules (plain-file "ip6tables.rules" "*filter
  13219. :INPUT ACCEPT
  13220. :FORWARD ACCEPT
  13221. :OUTPUT ACCEPT
  13222. -A INPUT -p tcp --dport 22 -j ACCEPT
  13223. -A INPUT -j REJECT --reject-with icmp6-port-unreachable
  13224. COMMIT
  13225. "))))
  13226. @end lisp
  13227. @end defvr
  13228. @deftp {Data Type} iptables-configuration
  13229. The data type representing the configuration of iptables.
  13230. @table @asis
  13231. @item @code{iptables} (default: @code{iptables})
  13232. The iptables package that provides @code{iptables-restore} and
  13233. @code{ip6tables-restore}.
  13234. @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
  13235. The iptables rules to use. It will be passed to @code{iptables-restore}.
  13236. This may be any ``file-like'' object (@pxref{G-Expressions, file-like
  13237. objects}).
  13238. @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
  13239. The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
  13240. This may be any ``file-like'' object (@pxref{G-Expressions, file-like
  13241. objects}).
  13242. @end table
  13243. @end deftp
  13244. @cindex nftables
  13245. @defvr {Scheme Variable} nftables-service-type
  13246. This is the service type to set up a nftables configuration. nftables is a
  13247. netfilter project that aims to replace the existing iptables, ip6tables,
  13248. arptables and ebtables framework. It provides a new packet filtering
  13249. framework, a new user-space utility @command{nft}, and a compatibility layer
  13250. for iptables. This service comes with a default ruleset
  13251. @code{%default-nftables-ruleset} that rejecting all incomming connections
  13252. except those to the ssh port 22. To use it, simply write:
  13253. @lisp
  13254. (service nftables-service-type)
  13255. @end lisp
  13256. @end defvr
  13257. @deftp {Data Type} nftables-configuration
  13258. The data type representing the configuration of nftables.
  13259. @table @asis
  13260. @item @code{package} (default: @code{nftables})
  13261. The nftables package that provides @command{nft}.
  13262. @item @code{ruleset} (default: @code{%default-nftables-ruleset})
  13263. The nftables ruleset to use. This may be any ``file-like'' object
  13264. (@pxref{G-Expressions, file-like objects}).
  13265. @end table
  13266. @end deftp
  13267. @cindex NTP (Network Time Protocol), service
  13268. @cindex ntpd, service for the Network Time Protocol daemon
  13269. @cindex real time clock
  13270. @defvr {Scheme Variable} ntp-service-type
  13271. This is the type of the service running the @uref{https://www.ntp.org,
  13272. Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
  13273. system clock synchronized with that of the specified NTP servers.
  13274. The value of this service is an @code{ntpd-configuration} object, as described
  13275. below.
  13276. @end defvr
  13277. @deftp {Data Type} ntp-configuration
  13278. This is the data type for the NTP service configuration.
  13279. @table @asis
  13280. @item @code{servers} (default: @code{%ntp-servers})
  13281. This is the list of servers (@code{<ntp-server>} records) with which
  13282. @command{ntpd} will be synchronized. See the @code{ntp-server} data type
  13283. definition below.
  13284. @item @code{allow-large-adjustment?} (default: @code{#t})
  13285. This determines whether @command{ntpd} is allowed to make an initial
  13286. adjustment of more than 1,000 seconds.
  13287. @item @code{ntp} (default: @code{ntp})
  13288. The NTP package to use.
  13289. @end table
  13290. @end deftp
  13291. @defvr {Scheme Variable} %ntp-servers
  13292. List of host names used as the default NTP servers. These are servers of the
  13293. @uref{https://www.ntppool.org/en/, NTP Pool Project}.
  13294. @end defvr
  13295. @deftp {Data Type} ntp-server
  13296. The data type representing the configuration of a NTP server.
  13297. @table @asis
  13298. @item @code{type} (default: @code{'server})
  13299. The type of the NTP server, given as a symbol. One of @code{'pool},
  13300. @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
  13301. @item @code{address}
  13302. The address of the server, as a string.
  13303. @item @code{options}
  13304. NTPD options to use with that specific server, given as a list of option names
  13305. and/or of option names and values tuples. The following example define a server
  13306. to use with the options @option{iburst} and @option{prefer}, as well as
  13307. @option{version} 3 and a @option{maxpoll} time of 16 seconds.
  13308. @example
  13309. (ntp-server
  13310. (type 'server)
  13311. (address "some.ntp.server.org")
  13312. (options `(iburst (version 3) (maxpoll 16) prefer))))
  13313. @end example
  13314. @end table
  13315. @end deftp
  13316. @cindex OpenNTPD
  13317. @deffn {Scheme Procedure} openntpd-service-type
  13318. Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
  13319. by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
  13320. clock synchronized with that of the given servers.
  13321. @lisp
  13322. (service
  13323. openntpd-service-type
  13324. (openntpd-configuration
  13325. (listen-on '("127.0.0.1" "::1"))
  13326. (sensor '("udcf0 correction 70000"))
  13327. (constraint-from '("www.gnu.org"))
  13328. (constraints-from '("https://www.google.com/"))))
  13329. @end lisp
  13330. @end deffn
  13331. @defvr {Scheme Variable} %openntpd-servers
  13332. This variable is a list of the server addresses defined in
  13333. @code{%ntp-servers}.
  13334. @end defvr
  13335. @deftp {Data Type} openntpd-configuration
  13336. @table @asis
  13337. @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
  13338. The openntpd executable to use.
  13339. @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
  13340. A list of local IP addresses or hostnames the ntpd daemon should listen on.
  13341. @item @code{query-from} (default: @code{'()})
  13342. A list of local IP address the ntpd daemon should use for outgoing queries.
  13343. @item @code{sensor} (default: @code{'()})
  13344. Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
  13345. will listen to each sensor that actually exists and ignore non-existent ones.
  13346. See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
  13347. information.
  13348. @item @code{server} (default: @code{'()})
  13349. Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
  13350. @item @code{servers} (default: @code{%openntp-servers})
  13351. Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
  13352. @item @code{constraint-from} (default: @code{'()})
  13353. @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
  13354. This time information is not used for precision but acts as an authenticated
  13355. constraint, thereby reducing the impact of unauthenticated NTP
  13356. man-in-the-middle attacks.
  13357. Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
  13358. a constraint.
  13359. @item @code{constraints-from} (default: @code{'()})
  13360. As with constraint from, specify a list of URLs, IP addresses or hostnames of
  13361. HTTPS servers to provide a constraint. Should the hostname resolve to multiple
  13362. IP addresses, @code{ntpd} will calculate a median constraint from all of them.
  13363. @end table
  13364. @end deftp
  13365. @cindex inetd
  13366. @deffn {Scheme variable} inetd-service-type
  13367. This service runs the @command{inetd} (@pxref{inetd invocation,,,
  13368. inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
  13369. connections on internet sockets, and lazily starts the specified server
  13370. program when a connection is made on one of these sockets.
  13371. The value of this service is an @code{inetd-configuration} object. The
  13372. following example configures the @command{inetd} daemon to provide the
  13373. built-in @command{echo} service, as well as an smtp service which
  13374. forwards smtp traffic over ssh to a server @code{smtp-server} behind a
  13375. gateway @code{hostname}:
  13376. @lisp
  13377. (service
  13378. inetd-service-type
  13379. (inetd-configuration
  13380. (entries (list
  13381. (inetd-entry
  13382. (name "echo")
  13383. (socket-type 'stream)
  13384. (protocol "tcp")
  13385. (wait? #f)
  13386. (user "root"))
  13387. (inetd-entry
  13388. (node "127.0.0.1")
  13389. (name "smtp")
  13390. (socket-type 'stream)
  13391. (protocol "tcp")
  13392. (wait? #f)
  13393. (user "root")
  13394. (program (file-append openssh "/bin/ssh"))
  13395. (arguments
  13396. '("ssh" "-qT" "-i" "/path/to/ssh_key"
  13397. "-W" "smtp-server:25" "user@@hostname")))))))
  13398. @end lisp
  13399. See below for more details about @code{inetd-configuration}.
  13400. @end deffn
  13401. @deftp {Data Type} inetd-configuration
  13402. Data type representing the configuration of @command{inetd}.
  13403. @table @asis
  13404. @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
  13405. The @command{inetd} executable to use.
  13406. @item @code{entries} (default: @code{'()})
  13407. A list of @command{inetd} service entries. Each entry should be created
  13408. by the @code{inetd-entry} constructor.
  13409. @end table
  13410. @end deftp
  13411. @deftp {Data Type} inetd-entry
  13412. Data type representing an entry in the @command{inetd} configuration.
  13413. Each entry corresponds to a socket where @command{inetd} will listen for
  13414. requests.
  13415. @table @asis
  13416. @item @code{node} (default: @code{#f})
  13417. Optional string, a comma-separated list of local addresses
  13418. @command{inetd} should use when listening for this service.
  13419. @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
  13420. description of all options.
  13421. @item @code{name}
  13422. A string, the name must correspond to an entry in @code{/etc/services}.
  13423. @item @code{socket-type}
  13424. One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
  13425. @code{'seqpacket}.
  13426. @item @code{protocol}
  13427. A string, must correspond to an entry in @code{/etc/protocols}.
  13428. @item @code{wait?} (default: @code{#t})
  13429. Whether @command{inetd} should wait for the server to exit before
  13430. listening to new service requests.
  13431. @item @code{user}
  13432. A string containing the user (and, optionally, group) name of the user
  13433. as whom the server should run. The group name can be specified in a
  13434. suffix, separated by a colon or period, i.e.@: @code{"user"},
  13435. @code{"user:group"} or @code{"user.group"}.
  13436. @item @code{program} (default: @code{"internal"})
  13437. The server program which will serve the requests, or @code{"internal"}
  13438. if @command{inetd} should use a built-in service.
  13439. @item @code{arguments} (default: @code{'()})
  13440. A list strings or file-like objects, which are the server program's
  13441. arguments, starting with the zeroth argument, i.e.@: the name of the
  13442. program itself. For @command{inetd}'s internal services, this entry
  13443. must be @code{'()} or @code{'("internal")}.
  13444. @end table
  13445. @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
  13446. detailed discussion of each configuration field.
  13447. @end deftp
  13448. @cindex Tor
  13449. @defvr {Scheme Variable} tor-service-type
  13450. This is the type for a service that runs the @uref{https://torproject.org,
  13451. Tor} anonymous networking daemon. The service is configured using a
  13452. @code{<tor-configuration>} record. By default, the Tor daemon runs as the
  13453. @code{tor} unprivileged user, which is a member of the @code{tor} group.
  13454. @end defvr
  13455. @deftp {Data Type} tor-configuration
  13456. @table @asis
  13457. @item @code{tor} (default: @code{tor})
  13458. The package that provides the Tor daemon. This package is expected to provide
  13459. the daemon at @file{bin/tor} relative to its output directory. The default
  13460. package is the @uref{https://www.torproject.org, Tor Project's}
  13461. implementation.
  13462. @item @code{config-file} (default: @code{(plain-file "empty" "")})
  13463. The configuration file to use. It will be appended to a default configuration
  13464. file, and the final configuration file will be passed to @code{tor} via its
  13465. @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
  13466. file-like objects}). See @code{man tor} for details on the configuration file
  13467. syntax.
  13468. @item @code{hidden-services} (default: @code{'()})
  13469. The list of @code{<hidden-service>} records to use. For any hidden service
  13470. you include in this list, appropriate configuration to enable the hidden
  13471. service will be automatically added to the default configuration file. You
  13472. may conveniently create @code{<hidden-service>} records using the
  13473. @code{tor-hidden-service} procedure described below.
  13474. @item @code{socks-socket-type} (default: @code{'tcp})
  13475. The default socket type that Tor should use for its SOCKS socket. This must
  13476. be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
  13477. Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
  13478. If it is @code{'unix}, then Tor will listen on the UNIX domain socket
  13479. @file{/var/run/tor/socks-sock}, which will be made writable by members of the
  13480. @code{tor} group.
  13481. If you want to customize the SOCKS socket in more detail, leave
  13482. @code{socks-socket-type} at its default value of @code{'tcp} and use
  13483. @code{config-file} to override the default by providing your own
  13484. @code{SocksPort} option.
  13485. @item @code{control-socket?} (default: @code{#f})
  13486. Whether or not to provide a ``control socket'' by which Tor can be
  13487. controlled to, for instance, dynamically instantiate tor onion services.
  13488. If @code{#t}, Tor will listen for control commands on the UNIX domain socket
  13489. @file{/var/run/tor/control-sock}, which will be made writable by members of the
  13490. @code{tor} group.
  13491. @end table
  13492. @end deftp
  13493. @cindex hidden service
  13494. @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
  13495. Define a new Tor @dfn{hidden service} called @var{name} and implementing
  13496. @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
  13497. @example
  13498. '((22 "127.0.0.1:22")
  13499. (80 "127.0.0.1:8080"))
  13500. @end example
  13501. In this example, port 22 of the hidden service is mapped to local port 22, and
  13502. port 80 is mapped to local port 8080.
  13503. This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
  13504. the @file{hostname} file contains the @code{.onion} host name for the hidden
  13505. service.
  13506. See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
  13507. project's documentation} for more information.
  13508. @end deffn
  13509. The @code{(gnu services rsync)} module provides the following services:
  13510. You might want an rsync daemon if you have files that you want available
  13511. so anyone (or just yourself) can download existing files or upload new
  13512. files.
  13513. @deffn {Scheme Variable} rsync-service-type
  13514. This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
  13515. The value for this service type is a
  13516. @command{rsync-configuration} record as in this example:
  13517. @lisp
  13518. (service rsync-service-type)
  13519. @end lisp
  13520. See below for details about @code{rsync-configuration}.
  13521. @end deffn
  13522. @deftp {Data Type} rsync-configuration
  13523. Data type representing the configuration for @code{rsync-service}.
  13524. @table @asis
  13525. @item @code{package} (default: @var{rsync})
  13526. @code{rsync} package to use.
  13527. @item @code{port-number} (default: @code{873})
  13528. TCP port on which @command{rsync} listens for incoming connections. If port
  13529. is less than @code{1024} @command{rsync} needs to be started as the
  13530. @code{root} user and group.
  13531. @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
  13532. Name of the file where @command{rsync} writes its PID.
  13533. @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
  13534. Name of the file where @command{rsync} writes its lock file.
  13535. @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
  13536. Name of the file where @command{rsync} writes its log file.
  13537. @item @code{use-chroot?} (default: @var{#t})
  13538. Whether to use chroot for @command{rsync} shared directory.
  13539. @item @code{share-path} (default: @file{/srv/rsync})
  13540. Location of the @command{rsync} shared directory.
  13541. @item @code{share-comment} (default: @code{"Rsync share"})
  13542. Comment of the @command{rsync} shared directory.
  13543. @item @code{read-only?} (default: @var{#f})
  13544. Read-write permissions to shared directory.
  13545. @item @code{timeout} (default: @code{300})
  13546. I/O timeout in seconds.
  13547. @item @code{user} (default: @var{"root"})
  13548. Owner of the @code{rsync} process.
  13549. @item @code{group} (default: @var{"root"})
  13550. Group of the @code{rsync} process.
  13551. @item @code{uid} (default: @var{"rsyncd"})
  13552. User name or user ID that file transfers to and from that module should take
  13553. place as when the daemon was run as @code{root}.
  13554. @item @code{gid} (default: @var{"rsyncd"})
  13555. Group name or group ID that will be used when accessing the module.
  13556. @end table
  13557. @end deftp
  13558. The @code{(gnu services syncthing)} module provides the following services:
  13559. @cindex syncthing
  13560. You might want a syncthing daemon if you have files between two or more
  13561. computers and want to sync them in real time, safely protected from
  13562. prying eyes.
  13563. @deffn {Scheme Variable} syncthing-service-type
  13564. This is the service type for the @uref{https://syncthing.net/,
  13565. syncthing} daemon, The value for this service type is a
  13566. @command{syncthing-configuration} record as in this example:
  13567. @lisp
  13568. (service syncthing-service-type
  13569. (syncthing-configuration (user "alice")))
  13570. @end lisp
  13571. See below for details about @code{syncthing-configuration}.
  13572. @deftp {Data Type} syncthing-configuration
  13573. Data type representing the configuration for @code{syncthing-service-type}.
  13574. @table @asis
  13575. @item @code{syncthing} (default: @var{syncthing})
  13576. @code{syncthing} package to use.
  13577. @item @code{arguments} (default: @var{'()})
  13578. List of command-line arguments passing to @code{syncthing} binary.
  13579. @item @code{logflags} (default: @var{0})
  13580. Sum of loging flags, see
  13581. @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
  13582. @item @code{user} (default: @var{#f})
  13583. The user as which the Syncthing service is to be run.
  13584. This assumes that the specified user exists.
  13585. @item @code{group} (default: @var{"users"})
  13586. The group as which the Syncthing service is to be run.
  13587. This assumes that the specified group exists.
  13588. @item @code{home} (default: @var{#f})
  13589. Common configuration and data directory. The default configuration
  13590. directory is @file{$HOME} of the specified Syncthing @code{user}.
  13591. @end table
  13592. @end deftp
  13593. @end deffn
  13594. Furthermore, @code{(gnu services ssh)} provides the following services.
  13595. @cindex SSH
  13596. @cindex SSH server
  13597. @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
  13598. [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
  13599. [#:allow-empty-passwords? #f] [#:root-login? #f] @
  13600. [#:syslog-output? #t] [#:x11-forwarding? #t] @
  13601. [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
  13602. [#:public-key-authentication? #t] [#:initialize? #t]
  13603. Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
  13604. @var{host-key} must designate a file containing the host key, and readable
  13605. only by root.
  13606. When @var{daemonic?} is true, @command{lshd} will detach from the
  13607. controlling terminal and log its output to syslogd, unless one sets
  13608. @var{syslog-output?} to false. Obviously, it also makes lsh-service
  13609. depend on existence of syslogd service. When @var{pid-file?} is true,
  13610. @command{lshd} writes its PID to the file called @var{pid-file}.
  13611. When @var{initialize?} is true, automatically create the seed and host key
  13612. upon service activation if they do not exist yet. This may take long and
  13613. require interaction.
  13614. When @var{initialize?} is false, it is up to the user to initialize the
  13615. randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
  13616. a key pair with the private key stored in file @var{host-key} (@pxref{lshd
  13617. basics,,, lsh, LSH Manual}).
  13618. When @var{interfaces} is empty, lshd listens for connections on all the
  13619. network interfaces; otherwise, @var{interfaces} must be a list of host names
  13620. or addresses.
  13621. @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
  13622. passwords, and @var{root-login?} specifies whether to accept log-ins as
  13623. root.
  13624. The other options should be self-descriptive.
  13625. @end deffn
  13626. @cindex SSH
  13627. @cindex SSH server
  13628. @deffn {Scheme Variable} openssh-service-type
  13629. This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
  13630. shell daemon, @command{sshd}. Its value must be an
  13631. @code{openssh-configuration} record as in this example:
  13632. @lisp
  13633. (service openssh-service-type
  13634. (openssh-configuration
  13635. (x11-forwarding? #t)
  13636. (permit-root-login 'without-password)
  13637. (authorized-keys
  13638. `(("alice" ,(local-file "alice.pub"))
  13639. ("bob" ,(local-file "bob.pub"))))))
  13640. @end lisp
  13641. See below for details about @code{openssh-configuration}.
  13642. This service can be extended with extra authorized keys, as in this
  13643. example:
  13644. @lisp
  13645. (service-extension openssh-service-type
  13646. (const `(("charlie"
  13647. ,(local-file "charlie.pub")))))
  13648. @end lisp
  13649. @end deffn
  13650. @deftp {Data Type} openssh-configuration
  13651. This is the configuration record for OpenSSH's @command{sshd}.
  13652. @table @asis
  13653. @item @code{openssh} (default @var{openssh})
  13654. The Openssh package to use.
  13655. @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
  13656. Name of the file where @command{sshd} writes its PID.
  13657. @item @code{port-number} (default: @code{22})
  13658. TCP port on which @command{sshd} listens for incoming connections.
  13659. @item @code{permit-root-login} (default: @code{#f})
  13660. This field determines whether and when to allow logins as root. If
  13661. @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
  13662. If it's the symbol @code{'without-password}, then root logins are
  13663. permitted but not with password-based authentication.
  13664. @item @code{allow-empty-passwords?} (default: @code{#f})
  13665. When true, users with empty passwords may log in. When false, they may
  13666. not.
  13667. @item @code{password-authentication?} (default: @code{#t})
  13668. When true, users may log in with their password. When false, they have
  13669. other authentication methods.
  13670. @item @code{public-key-authentication?} (default: @code{#t})
  13671. When true, users may log in using public key authentication. When
  13672. false, users have to use other authentication method.
  13673. Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
  13674. This is used only by protocol version 2.
  13675. @item @code{x11-forwarding?} (default: @code{#f})
  13676. When true, forwarding of X11 graphical client connections is
  13677. enabled---in other words, @command{ssh} options @option{-X} and
  13678. @option{-Y} will work.
  13679. @item @code{allow-agent-forwarding?} (default: @code{#t})
  13680. Whether to allow agent forwarding.
  13681. @item @code{allow-tcp-forwarding?} (default: @code{#t})
  13682. Whether to allow TCP forwarding.
  13683. @item @code{gateway-ports?} (default: @code{#f})
  13684. Whether to allow gateway ports.
  13685. @item @code{challenge-response-authentication?} (default: @code{#f})
  13686. Specifies whether challenge response authentication is allowed (e.g.@: via
  13687. PAM).
  13688. @item @code{use-pam?} (default: @code{#t})
  13689. Enables the Pluggable Authentication Module interface. If set to
  13690. @code{#t}, this will enable PAM authentication using
  13691. @code{challenge-response-authentication?} and
  13692. @code{password-authentication?}, in addition to PAM account and session
  13693. module processing for all authentication types.
  13694. Because PAM challenge response authentication usually serves an
  13695. equivalent role to password authentication, you should disable either
  13696. @code{challenge-response-authentication?} or
  13697. @code{password-authentication?}.
  13698. @item @code{print-last-log?} (default: @code{#t})
  13699. Specifies whether @command{sshd} should print the date and time of the
  13700. last user login when a user logs in interactively.
  13701. @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
  13702. Configures external subsystems (e.g.@: file transfer daemon).
  13703. This is a list of two-element lists, each of which containing the
  13704. subsystem name and a command (with optional arguments) to execute upon
  13705. subsystem request.
  13706. The command @command{internal-sftp} implements an in-process SFTP
  13707. server. Alternatively, one can specify the @command{sftp-server} command:
  13708. @lisp
  13709. (service openssh-service-type
  13710. (openssh-configuration
  13711. (subsystems
  13712. `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
  13713. @end lisp
  13714. @item @code{accepted-environment} (default: @code{'()})
  13715. List of strings describing which environment variables may be exported.
  13716. Each string gets on its own line. See the @code{AcceptEnv} option in
  13717. @code{man sshd_config}.
  13718. This example allows ssh-clients to export the @env{COLORTERM} variable.
  13719. It is set by terminal emulators, which support colors. You can use it in
  13720. your shell's resource file to enable colors for the prompt and commands
  13721. if this variable is set.
  13722. @lisp
  13723. (service openssh-service-type
  13724. (openssh-configuration
  13725. (accepted-environment '("COLORTERM"))))
  13726. @end lisp
  13727. @item @code{authorized-keys} (default: @code{'()})
  13728. @cindex authorized keys, SSH
  13729. @cindex SSH authorized keys
  13730. This is the list of authorized keys. Each element of the list is a user
  13731. name followed by one or more file-like objects that represent SSH public
  13732. keys. For example:
  13733. @lisp
  13734. (openssh-configuration
  13735. (authorized-keys
  13736. `(("rekado" ,(local-file "rekado.pub"))
  13737. ("chris" ,(local-file "chris.pub"))
  13738. ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
  13739. @end lisp
  13740. @noindent
  13741. registers the specified public keys for user accounts @code{rekado},
  13742. @code{chris}, and @code{root}.
  13743. Additional authorized keys can be specified @i{via}
  13744. @code{service-extension}.
  13745. Note that this does @emph{not} interfere with the use of
  13746. @file{~/.ssh/authorized_keys}.
  13747. @item @code{log-level} (default: @code{'info})
  13748. This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
  13749. @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
  13750. page for @file{sshd_config} for the full list of level names.
  13751. @item @code{extra-content} (default: @code{""})
  13752. This field can be used to append arbitrary text to the configuration file. It
  13753. is especially useful for elaborate configurations that cannot be expressed
  13754. otherwise. This configuration, for example, would generally disable root
  13755. logins, but permit them from one specific IP address:
  13756. @lisp
  13757. (openssh-configuration
  13758. (extra-content "\
  13759. Match Address 192.168.0.1
  13760. PermitRootLogin yes"))
  13761. @end lisp
  13762. @end table
  13763. @end deftp
  13764. @deffn {Scheme Procedure} dropbear-service [@var{config}]
  13765. Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
  13766. daemon} with the given @var{config}, a @code{<dropbear-configuration>}
  13767. object.
  13768. For example, to specify a Dropbear service listening on port 1234, add
  13769. this call to the operating system's @code{services} field:
  13770. @lisp
  13771. (dropbear-service (dropbear-configuration
  13772. (port-number 1234)))
  13773. @end lisp
  13774. @end deffn
  13775. @deftp {Data Type} dropbear-configuration
  13776. This data type represents the configuration of a Dropbear SSH daemon.
  13777. @table @asis
  13778. @item @code{dropbear} (default: @var{dropbear})
  13779. The Dropbear package to use.
  13780. @item @code{port-number} (default: 22)
  13781. The TCP port where the daemon waits for incoming connections.
  13782. @item @code{syslog-output?} (default: @code{#t})
  13783. Whether to enable syslog output.
  13784. @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
  13785. File name of the daemon's PID file.
  13786. @item @code{root-login?} (default: @code{#f})
  13787. Whether to allow @code{root} logins.
  13788. @item @code{allow-empty-passwords?} (default: @code{#f})
  13789. Whether to allow empty passwords.
  13790. @item @code{password-authentication?} (default: @code{#t})
  13791. Whether to enable password-based authentication.
  13792. @end table
  13793. @end deftp
  13794. @cindex AutoSSH
  13795. @deffn {Scheme Variable} autossh-service-type
  13796. This is the type for the @uref{https://www.harding.motd.ca/autossh,
  13797. AutoSSH} program that runs a copy of @command{ssh} and monitors it,
  13798. restarting it as necessary should it die or stop passing traffic.
  13799. AutoSSH can be run manually from the command-line by passing arguments
  13800. to the binary @command{autossh} from the package @code{autossh}, but it
  13801. can also be run as a Guix service. This latter use case is documented
  13802. here.
  13803. AutoSSH can be used to forward local traffic to a remote machine using
  13804. an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
  13805. is run as.
  13806. For example, to specify a service running autossh as the user
  13807. @code{pino} and forwarding all local connections to port @code{8081} to
  13808. @code{remote:8081} using an SSH tunnel, add this call to the operating
  13809. system's @code{services} field:
  13810. @lisp
  13811. (service autossh-service-type
  13812. (autossh-configuration
  13813. (user "pino")
  13814. (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
  13815. @end lisp
  13816. @end deffn
  13817. @deftp {Data Type} autossh-configuration
  13818. This data type represents the configuration of an AutoSSH service.
  13819. @table @asis
  13820. @item @code{user} (default @code{"autossh"})
  13821. The user as which the AutoSSH service is to be run.
  13822. This assumes that the specified user exists.
  13823. @item @code{poll} (default @code{600})
  13824. Specifies the connection poll time in seconds.
  13825. @item @code{first-poll} (default @code{#f})
  13826. Specifies how many seconds AutoSSH waits before the first connection
  13827. test. After this first test, polling is resumed at the pace defined in
  13828. @code{poll}. When set to @code{#f}, the first poll is not treated
  13829. specially and will also use the connection poll specified in
  13830. @code{poll}.
  13831. @item @code{gate-time} (default @code{30})
  13832. Specifies how many seconds an SSH connection must be active before it is
  13833. considered successful.
  13834. @item @code{log-level} (default @code{1})
  13835. The log level, corresponding to the levels used by syslog---so @code{0}
  13836. is the most silent while @code{7} is the chattiest.
  13837. @item @code{max-start} (default @code{#f})
  13838. The maximum number of times SSH may be (re)started before AutoSSH exits.
  13839. When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
  13840. @item @code{message} (default @code{""})
  13841. The message to append to the echo message sent when testing connections.
  13842. @item @code{port} (default @code{"0"})
  13843. The ports used for monitoring the connection. When set to @code{"0"},
  13844. monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
  13845. a positive integer, ports @var{n} and @var{n}+1 are used for
  13846. monitoring the connection, such that port @var{n} is the base
  13847. monitoring port and @code{n+1} is the echo port. When set to
  13848. @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
  13849. integers, the ports @var{n} and @var{m} are used for monitoring the
  13850. connection, such that port @var{n} is the base monitoring port and
  13851. @var{m} is the echo port.
  13852. @item @code{ssh-options} (default @code{'()})
  13853. The list of command-line arguments to pass to @command{ssh} when it is
  13854. run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
  13855. may cause undefined behaviour.
  13856. @end table
  13857. @end deftp
  13858. @cindex WebSSH
  13859. @deffn {Scheme Variable} webssh-service-type
  13860. This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
  13861. program that runs a web SSH client. WebSSH can be run manually from the
  13862. command-line by passing arguments to the binary @command{wssh} from the
  13863. package @code{webssh}, but it can also be run as a Guix service. This
  13864. latter use case is documented here.
  13865. For example, to specify a service running WebSSH on loopback interface
  13866. on port @code{8888} with reject policy with a list of allowed to
  13867. connection hosts, and NGINX as a reverse-proxy to this service listening
  13868. for HTTPS connection, add this call to the operating system's
  13869. @code{services} field:
  13870. @lisp
  13871. (service webssh-service-type
  13872. (webssh-configuration (address "127.0.0.1")
  13873. (port 8888)
  13874. (policy 'reject)
  13875. (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
  13876. "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
  13877. (service nginx-service-type
  13878. (nginx-configuration
  13879. (server-blocks
  13880. (list
  13881. (nginx-server-configuration
  13882. (inherit %webssh-configuration-nginx)
  13883. (server-name '("webssh.example.com"))
  13884. (listen '("443 ssl"))
  13885. (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
  13886. (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
  13887. (locations
  13888. (cons (nginx-location-configuration
  13889. (uri "/.well-known")
  13890. (body '("root /var/www;")))
  13891. (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
  13892. @end lisp
  13893. @end deffn
  13894. @deftp {Data Type} webssh-configuration
  13895. Data type representing the configuration for @code{webssh-service}.
  13896. @table @asis
  13897. @item @code{package} (default: @var{webssh})
  13898. @code{webssh} package to use.
  13899. @item @code{user-name} (default: @var{"webssh"})
  13900. User name or user ID that file transfers to and from that module should take
  13901. place.
  13902. @item @code{group-name} (default: @var{"webssh"})
  13903. Group name or group ID that will be used when accessing the module.
  13904. @item @code{address} (default: @var{#f})
  13905. IP address on which @command{webssh} listens for incoming connections.
  13906. @item @code{port} (default: @var{8888})
  13907. TCP port on which @command{webssh} listens for incoming connections.
  13908. @item @code{policy} (default: @var{#f})
  13909. Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
  13910. @item @code{known-hosts} (default: @var{'()})
  13911. List of hosts which allowed for SSH connection from @command{webssh}.
  13912. @item @code{log-file} (default: @file{"/var/log/webssh.log"})
  13913. Name of the file where @command{webssh} writes its log file.
  13914. @item @code{log-level} (default: @var{#f})
  13915. Logging level.
  13916. @end table
  13917. @end deftp
  13918. @defvr {Scheme Variable} %facebook-host-aliases
  13919. This variable contains a string for use in @file{/etc/hosts}
  13920. (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
  13921. line contains a entry that maps a known server name of the Facebook
  13922. on-line service---e.g., @code{www.facebook.com}---to the local
  13923. host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
  13924. This variable is typically used in the @code{hosts-file} field of an
  13925. @code{operating-system} declaration (@pxref{operating-system Reference,
  13926. @file{/etc/hosts}}):
  13927. @lisp
  13928. (use-modules (gnu) (guix))
  13929. (operating-system
  13930. (host-name "mymachine")
  13931. ;; ...
  13932. (hosts-file
  13933. ;; Create a /etc/hosts file with aliases for "localhost"
  13934. ;; and "mymachine", as well as for Facebook servers.
  13935. (plain-file "hosts"
  13936. (string-append (local-host-aliases host-name)
  13937. %facebook-host-aliases))))
  13938. @end lisp
  13939. This mechanism can prevent programs running locally, such as Web
  13940. browsers, from accessing Facebook.
  13941. @end defvr
  13942. The @code{(gnu services avahi)} provides the following definition.
  13943. @defvr {Scheme Variable} avahi-service-type
  13944. This is the service that runs @command{avahi-daemon}, a system-wide
  13945. mDNS/DNS-SD responder that allows for service discovery and
  13946. ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
  13947. Its value must be an @code{avahi-configuration} record---see below.
  13948. This service extends the name service cache daemon (nscd) so that it can
  13949. resolve @code{.local} host names using
  13950. @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
  13951. Service Switch}, for information on host name resolution.
  13952. Additionally, add the @var{avahi} package to the system profile so that
  13953. commands such as @command{avahi-browse} are directly usable.
  13954. @end defvr
  13955. @deftp {Data Type} avahi-configuration
  13956. Data type representation the configuration for Avahi.
  13957. @table @asis
  13958. @item @code{host-name} (default: @code{#f})
  13959. If different from @code{#f}, use that as the host name to
  13960. publish for this machine; otherwise, use the machine's actual host name.
  13961. @item @code{publish?} (default: @code{#t})
  13962. When true, allow host names and services to be published (broadcast) over the
  13963. network.
  13964. @item @code{publish-workstation?} (default: @code{#t})
  13965. When true, @command{avahi-daemon} publishes the machine's host name and IP
  13966. address via mDNS on the local network. To view the host names published on
  13967. your local network, you can run:
  13968. @example
  13969. avahi-browse _workstation._tcp
  13970. @end example
  13971. @item @code{wide-area?} (default: @code{#f})
  13972. When true, DNS-SD over unicast DNS is enabled.
  13973. @item @code{ipv4?} (default: @code{#t})
  13974. @itemx @code{ipv6?} (default: @code{#t})
  13975. These fields determine whether to use IPv4/IPv6 sockets.
  13976. @item @code{domains-to-browse} (default: @code{'()})
  13977. This is a list of domains to browse.
  13978. @end table
  13979. @end deftp
  13980. @deffn {Scheme Variable} openvswitch-service-type
  13981. This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
  13982. service, whose value should be an @code{openvswitch-configuration}
  13983. object.
  13984. @end deffn
  13985. @deftp {Data Type} openvswitch-configuration
  13986. Data type representing the configuration of Open vSwitch, a multilayer
  13987. virtual switch which is designed to enable massive network automation
  13988. through programmatic extension.
  13989. @table @asis
  13990. @item @code{package} (default: @var{openvswitch})
  13991. Package object of the Open vSwitch.
  13992. @end table
  13993. @end deftp
  13994. @defvr {Scheme Variable} pagekite-service-type
  13995. This is the service type for the @uref{https://pagekite.net, PageKite} service,
  13996. a tunneling solution for making localhost servers publicly visible, even from
  13997. behind restrictive firewalls or NAT without forwarded ports. The value for
  13998. this service type is a @code{pagekite-configuration} record.
  13999. Here's an example exposing the local HTTP and SSH daemons:
  14000. @lisp
  14001. (service pagekite-service-type
  14002. (pagekite-configuration
  14003. (kites '("http:@@kitename:localhost:80:@@kitesecret"
  14004. "raw/22:@@kitename:localhost:22:@@kitesecret"))
  14005. (extra-file "/etc/pagekite.rc")))
  14006. @end lisp
  14007. @end defvr
  14008. @deftp {Data Type} pagekite-configuration
  14009. Data type representing the configuration of PageKite.
  14010. @table @asis
  14011. @item @code{package} (default: @var{pagekite})
  14012. Package object of PageKite.
  14013. @item @code{kitename} (default: @code{#f})
  14014. PageKite name for authenticating to the frontend server.
  14015. @item @code{kitesecret} (default: @code{#f})
  14016. Shared secret for authenticating to the frontend server. You should probably
  14017. put this inside @code{extra-file} instead.
  14018. @item @code{frontend} (default: @code{#f})
  14019. Connect to the named PageKite frontend server instead of the
  14020. @uref{https://pagekite.net,,pagekite.net} service.
  14021. @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
  14022. List of service kites to use. Exposes HTTP on port 80 by default. The format
  14023. is @code{proto:kitename:host:port:secret}.
  14024. @item @code{extra-file} (default: @code{#f})
  14025. Extra configuration file to read, which you are expected to create manually.
  14026. Use this to add additional options and manage shared secrets out-of-band.
  14027. @end table
  14028. @end deftp
  14029. @defvr {Scheme Variable} yggdrasil-service-type
  14030. The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
  14031. Yggdrasil network}, an early-stage implementation of a fully end-to-end
  14032. encrypted IPv6 network.
  14033. @quotation
  14034. Yggdrasil provides name-independent routing with cryptographically generated
  14035. addresses. Static addressing means you can keep the same address as long as
  14036. you want, even if you move to a new location, or generate a new address (by
  14037. generating new keys) whenever you want.
  14038. @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
  14039. @end quotation
  14040. Pass it a value of @code{yggdrasil-configuration} to connect it to public
  14041. peers and/or local peers.
  14042. Here is an example using public peers and a static address. The static
  14043. signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
  14044. (the default value for @code{config-file}).
  14045. @lisp
  14046. ;; part of the operating-system declaration
  14047. (service yggdrasil-service-type
  14048. (yggdrasil-configuration
  14049. (autoconf? #f) ;; use only the public peers
  14050. (json-config
  14051. ;; choose one from
  14052. ;; https://github.com/yggdrasil-network/public-peers
  14053. '((peers . #("tcp://1.2.3.4:1337"))))
  14054. ;; /etc/yggdrasil-private.conf is the default value for config-file
  14055. ))
  14056. @end lisp
  14057. @example
  14058. # sample content for /etc/yggdrasil-private.conf
  14059. @{
  14060. # Your public encryption key. Your peers may ask you for this to put
  14061. # into their AllowedEncryptionPublicKeys configuration.
  14062. EncryptionPublicKey: 378dc5...
  14063. # Your private encryption key. DO NOT share this with anyone!
  14064. EncryptionPrivateKey: 0777...
  14065. # Your public signing key. You should not ordinarily need to share
  14066. # this with anyone.
  14067. SigningPublicKey: e1664...
  14068. # Your private signing key. DO NOT share this with anyone!
  14069. SigningPrivateKey: 0589d...
  14070. @}
  14071. @end example
  14072. @end defvr
  14073. @deftp {Data Type} yggdrasil-configuration
  14074. Data type representing the configuration of Yggdrasil.
  14075. @table @asis
  14076. @item @code{package} (default: @code{yggdrasil})
  14077. Package object of Yggdrasil.
  14078. @item @code{json-config} (default: @code{'()})
  14079. Contents of @file{/etc/yggdrasil.conf}. Will be merged with
  14080. @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
  14081. the Guix store, which is readable to all users. @strong{Do not store your
  14082. private keys in it}. See the output of @code{yggdrasil -genconf} for a
  14083. quick overview of valid keys and their default values.
  14084. @item @code{autoconf?} (default: @code{#f})
  14085. Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
  14086. and peer with IPv6 neighbors.
  14087. @item @code{log-level} (default: @code{'info})
  14088. How much detail to include in logs. Use @code{'debug} for more detail.
  14089. @item @code{log-to} (default: @code{'stdout})
  14090. Where to send logs. By default, the service logs standard output to
  14091. @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
  14092. sends output to the running syslog service.
  14093. @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
  14094. What HJSON file to load sensitive data from. This is where private keys
  14095. should be stored, which are necessary to specify if you don't want a
  14096. randomized address after each restart. Use @code{#f} to disable. Options
  14097. defined in this file take precedence over @code{json-config}. Use the output
  14098. of @code{yggdrasil -genconf} as a starting point. To configure a static
  14099. address, delete everything except these options:
  14100. @itemize
  14101. @item @code{EncryptionPublicKey}
  14102. @item @code{EncryptionPrivateKey}
  14103. @item @code{SigningPublicKey}
  14104. @item @code{SigningPrivateKey}
  14105. @end itemize
  14106. @end table
  14107. @end deftp
  14108. @cindex IPFS
  14109. @defvr {Scheme Variable} ipfs-service-type
  14110. The service type for connecting to the @uref{https://ipfs.io,IPFS network},
  14111. a global, versioned, peer-to-peer file system. Pass it a
  14112. @code{ipfs-configuration} to change the ports used for the gateway and API.
  14113. Here's an example configuration, using some non-standard ports:
  14114. @lisp
  14115. ;; part of the operating-system declaration
  14116. (service ipfs-service-type
  14117. (ipfs-configuration
  14118. (gateway "/ip4/127.0.0.1/tcp/8880")
  14119. (api "/ip4/127.0.0.1/tcp/8881")))
  14120. @end lisp
  14121. @end defvr
  14122. @deftp {Data Type} ipfs-configuration
  14123. Data type representing the configuration of IPFS.
  14124. @table @asis
  14125. @item @code{package} (default: @code{go-ipfs})
  14126. Package object of IPFS.
  14127. @item @code{gateway} (default: @code{"/ip4/127.0.0.1/tcp/8082"})
  14128. Address of the gateway, in ‘multiaddress’ format.
  14129. @item @code{api} (default: @code{"/ip4/127.0.0.1/tcp/5001"})
  14130. Address of the API endpoint, in ‘multiaddress’ format.
  14131. @end table
  14132. @end deftp
  14133. @cindex keepalived
  14134. @deffn {Scheme Variable} keepalived-service-type
  14135. This is the type for the @uref{https://www.keepalived.org/, Keepalived}
  14136. routing software, @command{keepalived}. Its value must be an
  14137. @code{keepalived-configuration} record as in this example for master
  14138. machine:
  14139. @lisp
  14140. (service keepalived-service-type
  14141. (keepalived-configuration
  14142. (config-file (local-file "keepalived-master.conf"))))
  14143. @end lisp
  14144. where @file{keepalived-master.conf}:
  14145. @example
  14146. vrrp_instance my-group @{
  14147. state MASTER
  14148. interface enp9s0
  14149. virtual_router_id 100
  14150. priority 100
  14151. unicast_peer @{ 10.0.0.2 @}
  14152. virtual_ipaddress @{
  14153. 10.0.0.4/24
  14154. @}
  14155. @}
  14156. @end example
  14157. and for backup machine:
  14158. @lisp
  14159. (service keepalived-service-type
  14160. (keepalived-configuration
  14161. (config-file (local-file "keepalived-backup.conf"))))
  14162. @end lisp
  14163. where @file{keepalived-backup.conf}:
  14164. @example
  14165. vrrp_instance my-group @{
  14166. state BACKUP
  14167. interface enp9s0
  14168. virtual_router_id 100
  14169. priority 99
  14170. unicast_peer @{ 10.0.0.3 @}
  14171. virtual_ipaddress @{
  14172. 10.0.0.4/24
  14173. @}
  14174. @}
  14175. @end example
  14176. @end deffn
  14177. @node Unattended Upgrades
  14178. @subsection Unattended Upgrades
  14179. @cindex unattended upgrades
  14180. @cindex upgrades, unattended
  14181. Guix provides a service to perform @emph{unattended upgrades}:
  14182. periodically, the system automatically reconfigures itself from the
  14183. latest Guix. Guix System has several properties that make unattended
  14184. upgrades safe:
  14185. @itemize
  14186. @item
  14187. upgrades are transactional (either the upgrade succeeds or it fails, but
  14188. you cannot end up with an ``in-between'' system state);
  14189. @item
  14190. the upgrade log is kept---you can view it with @command{guix system
  14191. list-generations}---and you can roll back to any previous generation,
  14192. should the upgraded system fail to behave as intended;
  14193. @item
  14194. channel code is authenticated so you know you can only run genuine code
  14195. (@pxref{Channels});
  14196. @item
  14197. @command{guix system reconfigure} prevents downgrades, which makes it
  14198. immune to @dfn{downgrade attacks}.
  14199. @end itemize
  14200. To set up unattended upgrades, add an instance of
  14201. @code{unattended-upgrade-service-type} like the one below to the list of
  14202. your operating system services:
  14203. @lisp
  14204. (service unattended-upgrade-service-type)
  14205. @end lisp
  14206. The defaults above set up weekly upgrades: every Sunday at midnight.
  14207. You do not need to provide the operating system configuration file: it
  14208. uses @file{/run/current-system/configuration.scm}, which ensures it
  14209. always uses your latest configuration---@pxref{provenance-service-type},
  14210. for more information about this file.
  14211. There are several things that can be configured, in particular the
  14212. periodicity and services (daemons) to be restarted upon completion.
  14213. When the upgrade is successful, the service takes care of deleting
  14214. system generations older that some threshold, as per @command{guix
  14215. system delete-generations}. See the reference below for details.
  14216. To ensure that upgrades are actually happening, you can run
  14217. @command{guix system describe}. To investigate upgrade failures, visit
  14218. the unattended upgrade log file (see below).
  14219. @defvr {Scheme Variable} unattended-upgrade-service-type
  14220. This is the service type for unattended upgrades. It sets up an mcron
  14221. job (@pxref{Scheduled Job Execution}) that runs @command{guix system
  14222. reconfigure} from the latest version of the specified channels.
  14223. Its value must be a @code{unattended-upgrade-configuration} record (see
  14224. below).
  14225. @end defvr
  14226. @deftp {Data Type} unattended-upgrade-configuration
  14227. This data type represents the configuration of the unattended upgrade
  14228. service. The following fields are available:
  14229. @table @asis
  14230. @item @code{schedule} (default: @code{"30 01 * * 0"})
  14231. This is the schedule of upgrades, expressed as a gexp containing an
  14232. mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
  14233. mcron, GNU@tie{}mcron}).
  14234. @item @code{channels} (default: @code{#~%default-channels})
  14235. This gexp specifies the channels to use for the upgrade
  14236. (@pxref{Channels}). By default, the tip of the official @code{guix}
  14237. channel is used.
  14238. @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
  14239. This field specifies the operating system configuration file to use.
  14240. The default is to reuse the config file of the current configuration.
  14241. There are cases, though, where referring to
  14242. @file{/run/current-system/configuration.scm} is not enough, for instance
  14243. because that file refers to extra files (SSH public keys, extra
  14244. configuration files, etc.) @i{via} @code{local-file} and similar
  14245. constructs. For those cases, we recommend something along these lines:
  14246. @lisp
  14247. (unattended-upgrade-configuration
  14248. (operating-system-file
  14249. (file-append (local-file "." "config-dir" #:recursive? #t)
  14250. "/config.scm")))
  14251. @end lisp
  14252. The effect here is to import all of the current directory into the
  14253. store, and to refer to @file{config.scm} within that directory.
  14254. Therefore, uses of @code{local-file} within @file{config.scm} will work
  14255. as expected. @xref{G-Expressions}, for information about
  14256. @code{local-file} and @code{file-append}.
  14257. @item @code{services-to-restart} (default: @code{'(mcron)})
  14258. This field specifies the Shepherd services to restart when the upgrade
  14259. completes.
  14260. Those services are restarted right away upon completion, as with
  14261. @command{herd restart}, which ensures that the latest version is
  14262. running---remember that by default @command{guix system reconfigure}
  14263. only restarts services that are not currently running, which is
  14264. conservative: it minimizes disruption but leaves outdated services
  14265. running.
  14266. Use @command{herd status} to find out candidates for restarting.
  14267. @xref{Services}, for general information about services. Common
  14268. services to restart would include @code{ntpd} and @code{ssh-daemon}.
  14269. By default, the @code{mcron} service is restarted. This ensures that
  14270. the latest version of the unattended upgrade job will be used next time.
  14271. @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
  14272. This is the expiration time in seconds for system generations. System
  14273. generations older that this amount of time are deleted with
  14274. @command{guix system delete-generations} when an upgrade completes.
  14275. @quotation Note
  14276. The unattended upgrade service does not run the garbage collector. You
  14277. will probably want to set up your own mcron job to run @command{guix gc}
  14278. periodically.
  14279. @end quotation
  14280. @item @code{maximum-duration} (default: @code{3600})
  14281. Maximum duration in seconds for the upgrade; past that time, the upgrade
  14282. aborts.
  14283. This is primarily useful to ensure the upgrade does not end up
  14284. rebuilding or re-downloading ``the world''.
  14285. @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
  14286. File where unattended upgrades are logged.
  14287. @end table
  14288. @end deftp
  14289. @node X Window
  14290. @subsection X Window
  14291. @cindex X11
  14292. @cindex X Window System
  14293. @cindex login manager
  14294. Support for the X Window graphical display system---specifically
  14295. Xorg---is provided by the @code{(gnu services xorg)} module. Note that
  14296. there is no @code{xorg-service} procedure. Instead, the X server is
  14297. started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
  14298. @cindex GDM
  14299. @cindex GNOME, login manager
  14300. GDM of course allows users to log in into window managers and desktop
  14301. environments other than GNOME; for those using GNOME, GDM is required for
  14302. features such as automatic screen locking.
  14303. @cindex window manager
  14304. To use X11, you must install at least one @dfn{window manager}---for
  14305. example the @code{windowmaker} or @code{openbox} packages---preferably
  14306. by adding it to the @code{packages} field of your operating system
  14307. definition (@pxref{operating-system Reference, system-wide packages}).
  14308. @defvr {Scheme Variable} gdm-service-type
  14309. This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
  14310. Desktop Manager} (GDM), a program that manages graphical display servers and
  14311. handles graphical user logins. Its value must be a @code{gdm-configuration}
  14312. (see below).
  14313. @cindex session types (X11)
  14314. @cindex X11 session types
  14315. GDM looks for @dfn{session types} described by the @file{.desktop} files in
  14316. @file{/run/current-system/profile/share/xsessions} and allows users to choose
  14317. a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
  14318. and @code{i3} provide @file{.desktop} files; adding them to the system-wide
  14319. set of packages automatically makes them available at the log-in screen.
  14320. In addition, @file{~/.xsession} files are honored. When available,
  14321. @file{~/.xsession} must be an executable that starts a window manager
  14322. and/or other X clients.
  14323. @end defvr
  14324. @deftp {Data Type} gdm-configuration
  14325. @table @asis
  14326. @item @code{auto-login?} (default: @code{#f})
  14327. @itemx @code{default-user} (default: @code{#f})
  14328. When @code{auto-login?} is false, GDM presents a log-in screen.
  14329. When @code{auto-login?} is true, GDM logs in directly as
  14330. @code{default-user}.
  14331. @item @code{debug?} (default: @code{#f})
  14332. When true, GDM writes debug messages to its log.
  14333. @item @code{gnome-shell-assets} (default: ...)
  14334. List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
  14335. @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
  14336. Configuration of the Xorg graphical server.
  14337. @item @code{xsession} (default: @code{(xinitrc)})
  14338. Script to run before starting a X session.
  14339. @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
  14340. File name of the @code{dbus-daemon} executable.
  14341. @item @code{gdm} (default: @code{gdm})
  14342. The GDM package to use.
  14343. @end table
  14344. @end deftp
  14345. @defvr {Scheme Variable} slim-service-type
  14346. This is the type for the SLiM graphical login manager for X11.
  14347. Like GDM, SLiM looks for session types described by @file{.desktop} files and
  14348. allows users to choose a session from the log-in screen using @kbd{F1}. It
  14349. also honors @file{~/.xsession} files.
  14350. Unlike GDM, SLiM does not spawn the user session on a different VT after
  14351. logging in, which means that you can only start one graphical session. If you
  14352. want to be able to run multiple graphical sessions at the same time you have
  14353. to add multiple SLiM services to your system services. The following example
  14354. shows how to replace the default GDM service with two SLiM services on tty7
  14355. and tty8.
  14356. @lisp
  14357. (use-modules (gnu services)
  14358. (gnu services desktop)
  14359. (gnu services xorg)
  14360. (srfi srfi-1)) ;for 'remove'
  14361. (operating-system
  14362. ;; ...
  14363. (services (cons* (service slim-service-type (slim-configuration
  14364. (display ":0")
  14365. (vt "vt7")))
  14366. (service slim-service-type (slim-configuration
  14367. (display ":1")
  14368. (vt "vt8")))
  14369. (remove (lambda (service)
  14370. (eq? (service-kind service) gdm-service-type))
  14371. %desktop-services))))
  14372. @end lisp
  14373. @end defvr
  14374. @deftp {Data Type} slim-configuration
  14375. Data type representing the configuration of @code{slim-service-type}.
  14376. @table @asis
  14377. @item @code{allow-empty-passwords?} (default: @code{#t})
  14378. Whether to allow logins with empty passwords.
  14379. @item @code{auto-login?} (default: @code{#f})
  14380. @itemx @code{default-user} (default: @code{""})
  14381. When @code{auto-login?} is false, SLiM presents a log-in screen.
  14382. When @code{auto-login?} is true, SLiM logs in directly as
  14383. @code{default-user}.
  14384. @item @code{theme} (default: @code{%default-slim-theme})
  14385. @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
  14386. The graphical theme to use and its name.
  14387. @item @code{auto-login-session} (default: @code{#f})
  14388. If true, this must be the name of the executable to start as the default
  14389. session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
  14390. If false, a session described by one of the available @file{.desktop}
  14391. files in @code{/run/current-system/profile} and @code{~/.guix-profile}
  14392. will be used.
  14393. @quotation Note
  14394. You must install at least one window manager in the system profile or in
  14395. your user profile. Failing to do that, if @code{auto-login-session} is
  14396. false, you will be unable to log in.
  14397. @end quotation
  14398. @item @code{xorg-configuration} (default @code{(xorg-configuration)})
  14399. Configuration of the Xorg graphical server.
  14400. @item @code{display} (default @code{":0"})
  14401. The display on which to start the Xorg graphical server.
  14402. @item @code{vt} (default @code{"vt7"})
  14403. The VT on which to start the Xorg graphical server.
  14404. @item @code{xauth} (default: @code{xauth})
  14405. The XAuth package to use.
  14406. @item @code{shepherd} (default: @code{shepherd})
  14407. The Shepherd package used when invoking @command{halt} and
  14408. @command{reboot}.
  14409. @item @code{sessreg} (default: @code{sessreg})
  14410. The sessreg package used in order to register the session.
  14411. @item @code{slim} (default: @code{slim})
  14412. The SLiM package to use.
  14413. @end table
  14414. @end deftp
  14415. @defvr {Scheme Variable} %default-theme
  14416. @defvrx {Scheme Variable} %default-theme-name
  14417. The default SLiM theme and its name.
  14418. @end defvr
  14419. @deftp {Data Type} sddm-configuration
  14420. This is the data type representing the SDDM service configuration.
  14421. @table @asis
  14422. @item @code{display-server} (default: "x11")
  14423. Select display server to use for the greeter. Valid values are
  14424. @samp{"x11"} or @samp{"wayland"}.
  14425. @item @code{numlock} (default: "on")
  14426. Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
  14427. @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
  14428. Command to run when halting.
  14429. @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
  14430. Command to run when rebooting.
  14431. @item @code{theme} (default "maldives")
  14432. Theme to use. Default themes provided by SDDM are @samp{"elarun"},
  14433. @samp{"maldives"} or @samp{"maya"}.
  14434. @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
  14435. Directory to look for themes.
  14436. @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
  14437. Directory to look for faces.
  14438. @item @code{default-path} (default "/run/current-system/profile/bin")
  14439. Default PATH to use.
  14440. @item @code{minimum-uid} (default: 1000)
  14441. Minimum UID displayed in SDDM and allowed for log-in.
  14442. @item @code{maximum-uid} (default: 2000)
  14443. Maximum UID to display in SDDM.
  14444. @item @code{remember-last-user?} (default #t)
  14445. Remember last user.
  14446. @item @code{remember-last-session?} (default #t)
  14447. Remember last session.
  14448. @item @code{hide-users} (default "")
  14449. Usernames to hide from SDDM greeter.
  14450. @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
  14451. Users with shells listed will be hidden from the SDDM greeter.
  14452. @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
  14453. Script to run before starting a wayland session.
  14454. @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
  14455. Directory to look for desktop files starting wayland sessions.
  14456. @item @code{xorg-configuration} (default @code{(xorg-configuration)})
  14457. Configuration of the Xorg graphical server.
  14458. @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
  14459. Path to xauth.
  14460. @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
  14461. Path to Xephyr.
  14462. @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
  14463. Script to run after starting xorg-server.
  14464. @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
  14465. Script to run before stopping xorg-server.
  14466. @item @code{xsession-command} (default: @code{xinitrc})
  14467. Script to run before starting a X session.
  14468. @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
  14469. Directory to look for desktop files starting X sessions.
  14470. @item @code{minimum-vt} (default: 7)
  14471. Minimum VT to use.
  14472. @item @code{auto-login-user} (default "")
  14473. User to use for auto-login.
  14474. @item @code{auto-login-session} (default "")
  14475. Desktop file to use for auto-login.
  14476. @item @code{relogin?} (default #f)
  14477. Relogin after logout.
  14478. @end table
  14479. @end deftp
  14480. @cindex login manager
  14481. @cindex X11 login
  14482. @defvr {Scheme Variable} sddm-service-type
  14483. This is the type of the service to run the
  14484. @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
  14485. must be a @code{sddm-configuration} record (see below).
  14486. Here's an example use:
  14487. @lisp
  14488. (service sddm-service-type
  14489. (sddm-configuration
  14490. (auto-login-user "alice")
  14491. (auto-login-session "xfce.desktop")))
  14492. @end lisp
  14493. @end defvr
  14494. @deftp {Data Type} sddm-configuration
  14495. This data type represents the configuration of the SDDM login manager.
  14496. The available fields are:
  14497. @table @asis
  14498. @item @code{sddm} (default: @code{sddm})
  14499. The SDDM package to use.
  14500. @item @code{display-server} (default: @code{"x11"})
  14501. This must be either @code{"x11"} or @code{"wayland"}.
  14502. @c FIXME: Add more fields.
  14503. @item @code{auto-login-user} (default: @code{""})
  14504. If non-empty, this is the user account under which to log in
  14505. automatically.
  14506. @item @code{auto-login-session} (default: @code{""})
  14507. If non-empty, this is the @file{.desktop} file name to use as the
  14508. auto-login session.
  14509. @end table
  14510. @end deftp
  14511. @cindex Xorg, configuration
  14512. @deftp {Data Type} xorg-configuration
  14513. This data type represents the configuration of the Xorg graphical display
  14514. server. Note that there is no Xorg service; instead, the X server is started
  14515. by a ``display manager'' such as GDM, SDDM, and SLiM@. Thus, the configuration
  14516. of these display managers aggregates an @code{xorg-configuration} record.
  14517. @table @asis
  14518. @item @code{modules} (default: @code{%default-xorg-modules})
  14519. This is a list of @dfn{module packages} loaded by the Xorg
  14520. server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
  14521. @item @code{fonts} (default: @code{%default-xorg-fonts})
  14522. This is a list of font directories to add to the server's @dfn{font path}.
  14523. @item @code{drivers} (default: @code{'()})
  14524. This must be either the empty list, in which case Xorg chooses a graphics
  14525. driver automatically, or a list of driver names that will be tried in this
  14526. order---e.g., @code{("modesetting" "vesa")}.
  14527. @item @code{resolutions} (default: @code{'()})
  14528. When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
  14529. resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
  14530. 768) (640 480))}.
  14531. @cindex keyboard layout, for Xorg
  14532. @cindex keymap, for Xorg
  14533. @item @code{keyboard-layout} (default: @code{#f})
  14534. If this is @code{#f}, Xorg uses the default keyboard layout---usually US
  14535. English (``qwerty'') for a 105-key PC keyboard.
  14536. Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
  14537. layout in use when Xorg is running. @xref{Keyboard Layout}, for more
  14538. information on how to specify the keyboard layout.
  14539. @item @code{extra-config} (default: @code{'()})
  14540. This is a list of strings or objects appended to the configuration file. It
  14541. is used to pass extra text to be added verbatim to the configuration file.
  14542. @item @code{server} (default: @code{xorg-server})
  14543. This is the package providing the Xorg server.
  14544. @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
  14545. This is the list of command-line arguments to pass to the X server. The
  14546. default is @code{-nolisten tcp}.
  14547. @end table
  14548. @end deftp
  14549. @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
  14550. [@var{login-manager-service-type}]
  14551. Tell the log-in manager (of type @var{login-manager-service-type}) to use
  14552. @var{config}, an @code{<xorg-configuration>} record.
  14553. Since the Xorg configuration is embedded in the log-in manager's
  14554. configuration---e.g., @code{gdm-configuration}---this procedure provides a
  14555. shorthand to set the Xorg configuration.
  14556. @end deffn
  14557. @deffn {Scheme Procedure} xorg-start-command [@var{config}]
  14558. Return a @code{startx} script in which the modules, fonts, etc. specified
  14559. in @var{config}, are available. The result should be used in place of
  14560. @code{startx}.
  14561. Usually the X server is started by a login manager.
  14562. @end deffn
  14563. @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
  14564. Add @var{package}, a package for a screen locker or screen saver whose
  14565. command is @var{program}, to the set of setuid programs and add a PAM entry
  14566. for it. For example:
  14567. @lisp
  14568. (screen-locker-service xlockmore "xlock")
  14569. @end lisp
  14570. makes the good ol' XlockMore usable.
  14571. @end deffn
  14572. @node Printing Services
  14573. @subsection Printing Services
  14574. @cindex printer support with CUPS
  14575. The @code{(gnu services cups)} module provides a Guix service definition
  14576. for the CUPS printing service. To add printer support to a Guix
  14577. system, add a @code{cups-service} to the operating system definition:
  14578. @deffn {Scheme Variable} cups-service-type
  14579. The service type for the CUPS print server. Its value should be a valid
  14580. CUPS configuration (see below). To use the default settings, simply
  14581. write:
  14582. @lisp
  14583. (service cups-service-type)
  14584. @end lisp
  14585. @end deffn
  14586. The CUPS configuration controls the basic things about your CUPS
  14587. installation: what interfaces it listens on, what to do if a print job
  14588. fails, how much logging to do, and so on. To actually add a printer,
  14589. you have to visit the @url{http://localhost:631} URL, or use a tool such
  14590. as GNOME's printer configuration services. By default, configuring a
  14591. CUPS service will generate a self-signed certificate if needed, for
  14592. secure connections to the print server.
  14593. Suppose you want to enable the Web interface of CUPS and also add
  14594. support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
  14595. package and for HP printers @i{via} the @code{hplip-minimal} package.
  14596. You can do that directly, like this (you need to use the
  14597. @code{(gnu packages cups)} module):
  14598. @lisp
  14599. (service cups-service-type
  14600. (cups-configuration
  14601. (web-interface? #t)
  14602. (extensions
  14603. (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
  14604. @end lisp
  14605. Note: If you wish to use the Qt5 based GUI which comes with the hplip
  14606. package then it is suggested that you install the @code{hplip} package,
  14607. either in your OS configuration file or as your user.
  14608. The available configuration parameters follow. Each parameter
  14609. definition is preceded by its type; for example, @samp{string-list foo}
  14610. indicates that the @code{foo} parameter should be specified as a list of
  14611. strings. There is also a way to specify the configuration as a string,
  14612. if you have an old @code{cupsd.conf} file that you want to port over
  14613. from some other system; see the end for more details.
  14614. @c The following documentation was initially generated by
  14615. @c (generate-documentation) in (gnu services cups). Manually maintained
  14616. @c documentation is better, so we shouldn't hesitate to edit below as
  14617. @c needed. However if the change you want to make to this documentation
  14618. @c can be done in an automated way, it's probably easier to change
  14619. @c (generate-documentation) than to make it below and have to deal with
  14620. @c the churn as CUPS updates.
  14621. Available @code{cups-configuration} fields are:
  14622. @deftypevr {@code{cups-configuration} parameter} package cups
  14623. The CUPS package.
  14624. @end deftypevr
  14625. @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
  14626. Drivers and other extensions to the CUPS package.
  14627. @end deftypevr
  14628. @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
  14629. Configuration of where to write logs, what directories to use for print
  14630. spools, and related privileged configuration parameters.
  14631. Available @code{files-configuration} fields are:
  14632. @deftypevr {@code{files-configuration} parameter} log-location access-log
  14633. Defines the access log filename. Specifying a blank filename disables
  14634. access log generation. The value @code{stderr} causes log entries to be
  14635. sent to the standard error file when the scheduler is running in the
  14636. foreground, or to the system log daemon when run in the background. The
  14637. value @code{syslog} causes log entries to be sent to the system log
  14638. daemon. The server name may be included in filenames using the string
  14639. @code{%s}, as in @code{/var/log/cups/%s-access_log}.
  14640. Defaults to @samp{"/var/log/cups/access_log"}.
  14641. @end deftypevr
  14642. @deftypevr {@code{files-configuration} parameter} file-name cache-dir
  14643. Where CUPS should cache data.
  14644. Defaults to @samp{"/var/cache/cups"}.
  14645. @end deftypevr
  14646. @deftypevr {@code{files-configuration} parameter} string config-file-perm
  14647. Specifies the permissions for all configuration files that the scheduler
  14648. writes.
  14649. Note that the permissions for the printers.conf file are currently
  14650. masked to only allow access from the scheduler user (typically root).
  14651. This is done because printer device URIs sometimes contain sensitive
  14652. authentication information that should not be generally known on the
  14653. system. There is no way to disable this security feature.
  14654. Defaults to @samp{"0640"}.
  14655. @end deftypevr
  14656. @deftypevr {@code{files-configuration} parameter} log-location error-log
  14657. Defines the error log filename. Specifying a blank filename disables
  14658. error log generation. The value @code{stderr} causes log entries to be
  14659. sent to the standard error file when the scheduler is running in the
  14660. foreground, or to the system log daemon when run in the background. The
  14661. value @code{syslog} causes log entries to be sent to the system log
  14662. daemon. The server name may be included in filenames using the string
  14663. @code{%s}, as in @code{/var/log/cups/%s-error_log}.
  14664. Defaults to @samp{"/var/log/cups/error_log"}.
  14665. @end deftypevr
  14666. @deftypevr {@code{files-configuration} parameter} string fatal-errors
  14667. Specifies which errors are fatal, causing the scheduler to exit. The
  14668. kind strings are:
  14669. @table @code
  14670. @item none
  14671. No errors are fatal.
  14672. @item all
  14673. All of the errors below are fatal.
  14674. @item browse
  14675. Browsing initialization errors are fatal, for example failed connections
  14676. to the DNS-SD daemon.
  14677. @item config
  14678. Configuration file syntax errors are fatal.
  14679. @item listen
  14680. Listen or Port errors are fatal, except for IPv6 failures on the
  14681. loopback or @code{any} addresses.
  14682. @item log
  14683. Log file creation or write errors are fatal.
  14684. @item permissions
  14685. Bad startup file permissions are fatal, for example shared TLS
  14686. certificate and key files with world-read permissions.
  14687. @end table
  14688. Defaults to @samp{"all -browse"}.
  14689. @end deftypevr
  14690. @deftypevr {@code{files-configuration} parameter} boolean file-device?
  14691. Specifies whether the file pseudo-device can be used for new printer
  14692. queues. The URI @uref{file:///dev/null} is always allowed.
  14693. Defaults to @samp{#f}.
  14694. @end deftypevr
  14695. @deftypevr {@code{files-configuration} parameter} string group
  14696. Specifies the group name or ID that will be used when executing external
  14697. programs.
  14698. Defaults to @samp{"lp"}.
  14699. @end deftypevr
  14700. @deftypevr {@code{files-configuration} parameter} string log-file-perm
  14701. Specifies the permissions for all log files that the scheduler writes.
  14702. Defaults to @samp{"0644"}.
  14703. @end deftypevr
  14704. @deftypevr {@code{files-configuration} parameter} log-location page-log
  14705. Defines the page log filename. Specifying a blank filename disables
  14706. page log generation. The value @code{stderr} causes log entries to be
  14707. sent to the standard error file when the scheduler is running in the
  14708. foreground, or to the system log daemon when run in the background. The
  14709. value @code{syslog} causes log entries to be sent to the system log
  14710. daemon. The server name may be included in filenames using the string
  14711. @code{%s}, as in @code{/var/log/cups/%s-page_log}.
  14712. Defaults to @samp{"/var/log/cups/page_log"}.
  14713. @end deftypevr
  14714. @deftypevr {@code{files-configuration} parameter} string remote-root
  14715. Specifies the username that is associated with unauthenticated accesses
  14716. by clients claiming to be the root user. The default is @code{remroot}.
  14717. Defaults to @samp{"remroot"}.
  14718. @end deftypevr
  14719. @deftypevr {@code{files-configuration} parameter} file-name request-root
  14720. Specifies the directory that contains print jobs and other HTTP request
  14721. data.
  14722. Defaults to @samp{"/var/spool/cups"}.
  14723. @end deftypevr
  14724. @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
  14725. Specifies the level of security sandboxing that is applied to print
  14726. filters, backends, and other child processes of the scheduler; either
  14727. @code{relaxed} or @code{strict}. This directive is currently only
  14728. used/supported on macOS.
  14729. Defaults to @samp{strict}.
  14730. @end deftypevr
  14731. @deftypevr {@code{files-configuration} parameter} file-name server-keychain
  14732. Specifies the location of TLS certificates and private keys. CUPS will
  14733. look for public and private keys in this directory: @file{.crt} files
  14734. for PEM-encoded certificates and corresponding @file{.key} files for
  14735. PEM-encoded private keys.
  14736. Defaults to @samp{"/etc/cups/ssl"}.
  14737. @end deftypevr
  14738. @deftypevr {@code{files-configuration} parameter} file-name server-root
  14739. Specifies the directory containing the server configuration files.
  14740. Defaults to @samp{"/etc/cups"}.
  14741. @end deftypevr
  14742. @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
  14743. Specifies whether the scheduler calls fsync(2) after writing
  14744. configuration or state files.
  14745. Defaults to @samp{#f}.
  14746. @end deftypevr
  14747. @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
  14748. Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
  14749. @end deftypevr
  14750. @deftypevr {@code{files-configuration} parameter} file-name temp-dir
  14751. Specifies the directory where temporary files are stored.
  14752. Defaults to @samp{"/var/spool/cups/tmp"}.
  14753. @end deftypevr
  14754. @deftypevr {@code{files-configuration} parameter} string user
  14755. Specifies the user name or ID that is used when running external
  14756. programs.
  14757. Defaults to @samp{"lp"}.
  14758. @end deftypevr
  14759. @deftypevr {@code{files-configuration} parameter} string set-env
  14760. Set the specified environment variable to be passed to child processes.
  14761. Defaults to @samp{"variable value"}.
  14762. @end deftypevr
  14763. @end deftypevr
  14764. @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
  14765. Specifies the logging level for the AccessLog file. The @code{config}
  14766. level logs when printers and classes are added, deleted, or modified and
  14767. when configuration files are accessed or updated. The @code{actions}
  14768. level logs when print jobs are submitted, held, released, modified, or
  14769. canceled, and any of the conditions for @code{config}. The @code{all}
  14770. level logs all requests.
  14771. Defaults to @samp{actions}.
  14772. @end deftypevr
  14773. @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
  14774. Specifies whether to purge job history data automatically when it is no
  14775. longer required for quotas.
  14776. Defaults to @samp{#f}.
  14777. @end deftypevr
  14778. @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
  14779. Specifies a list of DNS-SD sub-types to advertise for each shared printer.
  14780. For example, @samp{"_cups" "_print"} will tell network clients that both
  14781. CUPS sharing and IPP Everywhere are supported.
  14782. Defaults to @samp{"_cups"}.
  14783. @end deftypevr
  14784. @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
  14785. Specifies which protocols to use for local printer sharing.
  14786. Defaults to @samp{dnssd}.
  14787. @end deftypevr
  14788. @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
  14789. Specifies whether the CUPS web interface is advertised.
  14790. Defaults to @samp{#f}.
  14791. @end deftypevr
  14792. @deftypevr {@code{cups-configuration} parameter} boolean browsing?
  14793. Specifies whether shared printers are advertised.
  14794. Defaults to @samp{#f}.
  14795. @end deftypevr
  14796. @deftypevr {@code{cups-configuration} parameter} string classification
  14797. Specifies the security classification of the server. Any valid banner
  14798. name can be used, including @samp{"classified"}, @samp{"confidential"},
  14799. @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
  14800. banner can be omitted to disable secure printing functions.
  14801. Defaults to @samp{""}.
  14802. @end deftypevr
  14803. @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
  14804. Specifies whether users may override the classification (cover page) of
  14805. individual print jobs using the @code{job-sheets} option.
  14806. Defaults to @samp{#f}.
  14807. @end deftypevr
  14808. @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
  14809. Specifies the default type of authentication to use.
  14810. Defaults to @samp{Basic}.
  14811. @end deftypevr
  14812. @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
  14813. Specifies whether encryption will be used for authenticated requests.
  14814. Defaults to @samp{Required}.
  14815. @end deftypevr
  14816. @deftypevr {@code{cups-configuration} parameter} string default-language
  14817. Specifies the default language to use for text and web content.
  14818. Defaults to @samp{"en"}.
  14819. @end deftypevr
  14820. @deftypevr {@code{cups-configuration} parameter} string default-paper-size
  14821. Specifies the default paper size for new print queues. @samp{"Auto"}
  14822. uses a locale-specific default, while @samp{"None"} specifies there is
  14823. no default paper size. Specific size names are typically
  14824. @samp{"Letter"} or @samp{"A4"}.
  14825. Defaults to @samp{"Auto"}.
  14826. @end deftypevr
  14827. @deftypevr {@code{cups-configuration} parameter} string default-policy
  14828. Specifies the default access policy to use.
  14829. Defaults to @samp{"default"}.
  14830. @end deftypevr
  14831. @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
  14832. Specifies whether local printers are shared by default.
  14833. Defaults to @samp{#t}.
  14834. @end deftypevr
  14835. @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
  14836. Specifies the delay for updating of configuration and state files, in
  14837. seconds. A value of 0 causes the update to happen as soon as possible,
  14838. typically within a few milliseconds.
  14839. Defaults to @samp{30}.
  14840. @end deftypevr
  14841. @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
  14842. Specifies what to do when an error occurs. Possible values are
  14843. @code{abort-job}, which will discard the failed print job;
  14844. @code{retry-job}, which will retry the job at a later time;
  14845. @code{retry-current-job}, which retries the failed job immediately; and
  14846. @code{stop-printer}, which stops the printer.
  14847. Defaults to @samp{stop-printer}.
  14848. @end deftypevr
  14849. @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
  14850. Specifies the maximum cost of filters that are run concurrently, which
  14851. can be used to minimize disk, memory, and CPU resource problems. A
  14852. limit of 0 disables filter limiting. An average print to a
  14853. non-PostScript printer needs a filter limit of about 200. A PostScript
  14854. printer needs about half that (100). Setting the limit below these
  14855. thresholds will effectively limit the scheduler to printing a single job
  14856. at any time.
  14857. Defaults to @samp{0}.
  14858. @end deftypevr
  14859. @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
  14860. Specifies the scheduling priority of filters that are run to print a
  14861. job. The nice value ranges from 0, the highest priority, to 19, the
  14862. lowest priority.
  14863. Defaults to @samp{0}.
  14864. @end deftypevr
  14865. @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
  14866. Specifies whether to do reverse lookups on connecting clients. The
  14867. @code{double} setting causes @code{cupsd} to verify that the hostname
  14868. resolved from the address matches one of the addresses returned for that
  14869. hostname. Double lookups also prevent clients with unregistered
  14870. addresses from connecting to your server. Only set this option to
  14871. @code{#t} or @code{double} if absolutely required.
  14872. Defaults to @samp{#f}.
  14873. @end deftypevr
  14874. @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
  14875. Specifies the number of seconds to wait before killing the filters and
  14876. backend associated with a canceled or held job.
  14877. Defaults to @samp{30}.
  14878. @end deftypevr
  14879. @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
  14880. Specifies the interval between retries of jobs in seconds. This is
  14881. typically used for fax queues but can also be used with normal print
  14882. queues whose error policy is @code{retry-job} or
  14883. @code{retry-current-job}.
  14884. Defaults to @samp{30}.
  14885. @end deftypevr
  14886. @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
  14887. Specifies the number of retries that are done for jobs. This is
  14888. typically used for fax queues but can also be used with normal print
  14889. queues whose error policy is @code{retry-job} or
  14890. @code{retry-current-job}.
  14891. Defaults to @samp{5}.
  14892. @end deftypevr
  14893. @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
  14894. Specifies whether to support HTTP keep-alive connections.
  14895. Defaults to @samp{#t}.
  14896. @end deftypevr
  14897. @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
  14898. Specifies how long an idle client connection remains open, in seconds.
  14899. Defaults to @samp{30}.
  14900. @end deftypevr
  14901. @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
  14902. Specifies the maximum size of print files, IPP requests, and HTML form
  14903. data. A limit of 0 disables the limit check.
  14904. Defaults to @samp{0}.
  14905. @end deftypevr
  14906. @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
  14907. Listens on the specified interfaces for connections. Valid values are
  14908. of the form @var{address}:@var{port}, where @var{address} is either an
  14909. IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
  14910. indicate all addresses. Values can also be file names of local UNIX
  14911. domain sockets. The Listen directive is similar to the Port directive
  14912. but allows you to restrict access to specific interfaces or networks.
  14913. @end deftypevr
  14914. @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
  14915. Specifies the number of pending connections that will be allowed. This
  14916. normally only affects very busy servers that have reached the MaxClients
  14917. limit, but can also be triggered by large numbers of simultaneous
  14918. connections. When the limit is reached, the operating system will
  14919. refuse additional connections until the scheduler can accept the pending
  14920. ones.
  14921. Defaults to @samp{128}.
  14922. @end deftypevr
  14923. @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
  14924. Specifies a set of additional access controls.
  14925. Available @code{location-access-controls} fields are:
  14926. @deftypevr {@code{location-access-controls} parameter} file-name path
  14927. Specifies the URI path to which the access control applies.
  14928. @end deftypevr
  14929. @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
  14930. Access controls for all access to this path, in the same format as the
  14931. @code{access-controls} of @code{operation-access-control}.
  14932. Defaults to @samp{()}.
  14933. @end deftypevr
  14934. @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
  14935. Access controls for method-specific access to this path.
  14936. Defaults to @samp{()}.
  14937. Available @code{method-access-controls} fields are:
  14938. @deftypevr {@code{method-access-controls} parameter} boolean reverse?
  14939. If @code{#t}, apply access controls to all methods except the listed
  14940. methods. Otherwise apply to only the listed methods.
  14941. Defaults to @samp{#f}.
  14942. @end deftypevr
  14943. @deftypevr {@code{method-access-controls} parameter} method-list methods
  14944. Methods to which this access control applies.
  14945. Defaults to @samp{()}.
  14946. @end deftypevr
  14947. @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
  14948. Access control directives, as a list of strings. Each string should be
  14949. one directive, such as @samp{"Order allow,deny"}.
  14950. Defaults to @samp{()}.
  14951. @end deftypevr
  14952. @end deftypevr
  14953. @end deftypevr
  14954. @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
  14955. Specifies the number of debugging messages that are retained for logging
  14956. if an error occurs in a print job. Debug messages are logged regardless
  14957. of the LogLevel setting.
  14958. Defaults to @samp{100}.
  14959. @end deftypevr
  14960. @deftypevr {@code{cups-configuration} parameter} log-level log-level
  14961. Specifies the level of logging for the ErrorLog file. The value
  14962. @code{none} stops all logging while @code{debug2} logs everything.
  14963. Defaults to @samp{info}.
  14964. @end deftypevr
  14965. @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
  14966. Specifies the format of the date and time in the log files. The value
  14967. @code{standard} logs whole seconds while @code{usecs} logs microseconds.
  14968. Defaults to @samp{standard}.
  14969. @end deftypevr
  14970. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
  14971. Specifies the maximum number of simultaneous clients that are allowed by
  14972. the scheduler.
  14973. Defaults to @samp{100}.
  14974. @end deftypevr
  14975. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
  14976. Specifies the maximum number of simultaneous clients that are allowed
  14977. from a single address.
  14978. Defaults to @samp{100}.
  14979. @end deftypevr
  14980. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
  14981. Specifies the maximum number of copies that a user can print of each
  14982. job.
  14983. Defaults to @samp{9999}.
  14984. @end deftypevr
  14985. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
  14986. Specifies the maximum time a job may remain in the @code{indefinite}
  14987. hold state before it is canceled. A value of 0 disables cancellation of
  14988. held jobs.
  14989. Defaults to @samp{0}.
  14990. @end deftypevr
  14991. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
  14992. Specifies the maximum number of simultaneous jobs that are allowed. Set
  14993. to 0 to allow an unlimited number of jobs.
  14994. Defaults to @samp{500}.
  14995. @end deftypevr
  14996. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
  14997. Specifies the maximum number of simultaneous jobs that are allowed per
  14998. printer. A value of 0 allows up to MaxJobs jobs per printer.
  14999. Defaults to @samp{0}.
  15000. @end deftypevr
  15001. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
  15002. Specifies the maximum number of simultaneous jobs that are allowed per
  15003. user. A value of 0 allows up to MaxJobs jobs per user.
  15004. Defaults to @samp{0}.
  15005. @end deftypevr
  15006. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
  15007. Specifies the maximum time a job may take to print before it is
  15008. canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
  15009. Defaults to @samp{10800}.
  15010. @end deftypevr
  15011. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
  15012. Specifies the maximum size of the log files before they are rotated, in
  15013. bytes. The value 0 disables log rotation.
  15014. Defaults to @samp{1048576}.
  15015. @end deftypevr
  15016. @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
  15017. Specifies the maximum amount of time to allow between files in a
  15018. multiple file print job, in seconds.
  15019. Defaults to @samp{300}.
  15020. @end deftypevr
  15021. @deftypevr {@code{cups-configuration} parameter} string page-log-format
  15022. Specifies the format of PageLog lines. Sequences beginning with percent
  15023. (@samp{%}) characters are replaced with the corresponding information,
  15024. while all other characters are copied literally. The following percent
  15025. sequences are recognized:
  15026. @table @samp
  15027. @item %%
  15028. insert a single percent character
  15029. @item %@{name@}
  15030. insert the value of the specified IPP attribute
  15031. @item %C
  15032. insert the number of copies for the current page
  15033. @item %P
  15034. insert the current page number
  15035. @item %T
  15036. insert the current date and time in common log format
  15037. @item %j
  15038. insert the job ID
  15039. @item %p
  15040. insert the printer name
  15041. @item %u
  15042. insert the username
  15043. @end table
  15044. A value of the empty string disables page logging. The string @code{%p
  15045. %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
  15046. %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
  15047. standard items.
  15048. Defaults to @samp{""}.
  15049. @end deftypevr
  15050. @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
  15051. Passes the specified environment variable(s) to child processes; a list
  15052. of strings.
  15053. Defaults to @samp{()}.
  15054. @end deftypevr
  15055. @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
  15056. Specifies named access control policies.
  15057. Available @code{policy-configuration} fields are:
  15058. @deftypevr {@code{policy-configuration} parameter} string name
  15059. Name of the policy.
  15060. @end deftypevr
  15061. @deftypevr {@code{policy-configuration} parameter} string job-private-access
  15062. Specifies an access list for a job's private values. @code{@@ACL} maps
  15063. to the printer's requesting-user-name-allowed or
  15064. requesting-user-name-denied values. @code{@@OWNER} maps to the job's
  15065. owner. @code{@@SYSTEM} maps to the groups listed for the
  15066. @code{system-group} field of the @code{files-config} configuration,
  15067. which is reified into the @code{cups-files.conf(5)} file. Other
  15068. possible elements of the access list include specific user names, and
  15069. @code{@@@var{group}} to indicate members of a specific group. The
  15070. access list may also be simply @code{all} or @code{default}.
  15071. Defaults to @samp{"@@OWNER @@SYSTEM"}.
  15072. @end deftypevr
  15073. @deftypevr {@code{policy-configuration} parameter} string job-private-values
  15074. Specifies the list of job values to make private, or @code{all},
  15075. @code{default}, or @code{none}.
  15076. Defaults to @samp{"job-name job-originating-host-name
  15077. job-originating-user-name phone"}.
  15078. @end deftypevr
  15079. @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
  15080. Specifies an access list for a subscription's private values.
  15081. @code{@@ACL} maps to the printer's requesting-user-name-allowed or
  15082. requesting-user-name-denied values. @code{@@OWNER} maps to the job's
  15083. owner. @code{@@SYSTEM} maps to the groups listed for the
  15084. @code{system-group} field of the @code{files-config} configuration,
  15085. which is reified into the @code{cups-files.conf(5)} file. Other
  15086. possible elements of the access list include specific user names, and
  15087. @code{@@@var{group}} to indicate members of a specific group. The
  15088. access list may also be simply @code{all} or @code{default}.
  15089. Defaults to @samp{"@@OWNER @@SYSTEM"}.
  15090. @end deftypevr
  15091. @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
  15092. Specifies the list of job values to make private, or @code{all},
  15093. @code{default}, or @code{none}.
  15094. Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
  15095. notify-subscriber-user-name notify-user-data"}.
  15096. @end deftypevr
  15097. @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
  15098. Access control by IPP operation.
  15099. Defaults to @samp{()}.
  15100. @end deftypevr
  15101. @end deftypevr
  15102. @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
  15103. Specifies whether job files (documents) are preserved after a job is
  15104. printed. If a numeric value is specified, job files are preserved for
  15105. the indicated number of seconds after printing. Otherwise a boolean
  15106. value applies indefinitely.
  15107. Defaults to @samp{86400}.
  15108. @end deftypevr
  15109. @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
  15110. Specifies whether the job history is preserved after a job is printed.
  15111. If a numeric value is specified, the job history is preserved for the
  15112. indicated number of seconds after printing. If @code{#t}, the job
  15113. history is preserved until the MaxJobs limit is reached.
  15114. Defaults to @samp{#t}.
  15115. @end deftypevr
  15116. @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
  15117. Specifies the amount of time to wait for job completion before
  15118. restarting the scheduler.
  15119. Defaults to @samp{30}.
  15120. @end deftypevr
  15121. @deftypevr {@code{cups-configuration} parameter} string rip-cache
  15122. Specifies the maximum amount of memory to use when converting documents
  15123. into bitmaps for a printer.
  15124. Defaults to @samp{"128m"}.
  15125. @end deftypevr
  15126. @deftypevr {@code{cups-configuration} parameter} string server-admin
  15127. Specifies the email address of the server administrator.
  15128. Defaults to @samp{"root@@localhost.localdomain"}.
  15129. @end deftypevr
  15130. @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
  15131. The ServerAlias directive is used for HTTP Host header validation when
  15132. clients connect to the scheduler from external interfaces. Using the
  15133. special name @code{*} can expose your system to known browser-based DNS
  15134. rebinding attacks, even when accessing sites through a firewall. If the
  15135. auto-discovery of alternate names does not work, we recommend listing
  15136. each alternate name with a ServerAlias directive instead of using
  15137. @code{*}.
  15138. Defaults to @samp{*}.
  15139. @end deftypevr
  15140. @deftypevr {@code{cups-configuration} parameter} string server-name
  15141. Specifies the fully-qualified host name of the server.
  15142. Defaults to @samp{"localhost"}.
  15143. @end deftypevr
  15144. @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
  15145. Specifies what information is included in the Server header of HTTP
  15146. responses. @code{None} disables the Server header. @code{ProductOnly}
  15147. reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
  15148. reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
  15149. @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
  15150. the output of the @code{uname} command. @code{Full} reports @code{CUPS
  15151. 2.0.0 (@var{uname}) IPP/2.0}.
  15152. Defaults to @samp{Minimal}.
  15153. @end deftypevr
  15154. @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
  15155. Listens on the specified interfaces for encrypted connections. Valid
  15156. values are of the form @var{address}:@var{port}, where @var{address} is
  15157. either an IPv6 address enclosed in brackets, an IPv4 address, or
  15158. @code{*} to indicate all addresses.
  15159. Defaults to @samp{()}.
  15160. @end deftypevr
  15161. @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
  15162. Sets encryption options. By default, CUPS only supports encryption
  15163. using TLS v1.0 or higher using known secure cipher suites. Security is
  15164. reduced when @code{Allow} options are used, and enhanced when @code{Deny}
  15165. options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
  15166. suites, which are required for some older clients. The @code{AllowSSL3} option
  15167. enables SSL v3.0, which is required for some older clients that do not support
  15168. TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
  15169. @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
  15170. protocol version to TLS v1.1.
  15171. Defaults to @samp{()}.
  15172. @end deftypevr
  15173. @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
  15174. Specifies whether the scheduler requires clients to strictly adhere to
  15175. the IPP specifications.
  15176. Defaults to @samp{#f}.
  15177. @end deftypevr
  15178. @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
  15179. Specifies the HTTP request timeout, in seconds.
  15180. Defaults to @samp{300}.
  15181. @end deftypevr
  15182. @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
  15183. Specifies whether the web interface is enabled.
  15184. Defaults to @samp{#f}.
  15185. @end deftypevr
  15186. At this point you're probably thinking ``oh dear, Guix manual, I like
  15187. you but you can stop already with the configuration options''. Indeed.
  15188. However, one more point: it could be that you have an existing
  15189. @code{cupsd.conf} that you want to use. In that case, you can pass an
  15190. @code{opaque-cups-configuration} as the configuration of a
  15191. @code{cups-service-type}.
  15192. Available @code{opaque-cups-configuration} fields are:
  15193. @deftypevr {@code{opaque-cups-configuration} parameter} package cups
  15194. The CUPS package.
  15195. @end deftypevr
  15196. @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
  15197. The contents of the @code{cupsd.conf}, as a string.
  15198. @end deftypevr
  15199. @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
  15200. The contents of the @code{cups-files.conf} file, as a string.
  15201. @end deftypevr
  15202. For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
  15203. strings of the same name, you could instantiate a CUPS service like
  15204. this:
  15205. @lisp
  15206. (service cups-service-type
  15207. (opaque-cups-configuration
  15208. (cupsd.conf cupsd.conf)
  15209. (cups-files.conf cups-files.conf)))
  15210. @end lisp
  15211. @node Desktop Services
  15212. @subsection Desktop Services
  15213. The @code{(gnu services desktop)} module provides services that are
  15214. usually useful in the context of a ``desktop'' setup---that is, on a
  15215. machine running a graphical display server, possibly with graphical user
  15216. interfaces, etc. It also defines services that provide specific desktop
  15217. environments like GNOME, Xfce or MATE.
  15218. To simplify things, the module defines a variable containing the set of
  15219. services that users typically expect on a machine with a graphical
  15220. environment and networking:
  15221. @defvr {Scheme Variable} %desktop-services
  15222. This is a list of services that builds upon @code{%base-services} and
  15223. adds or adjusts services for a typical ``desktop'' setup.
  15224. In particular, it adds a graphical login manager (@pxref{X Window,
  15225. @code{gdm-service-type}}), screen lockers, a network management tool
  15226. (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
  15227. support (@pxref{Networking Services, @code{modem-manager-service-type}}),
  15228. energy and color management services, the @code{elogind} login and seat
  15229. manager, the Polkit privilege service, the GeoClue location service, the
  15230. AccountsService daemon that allows authorized users change system passwords,
  15231. an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
  15232. name service switch service configured to be able to use @code{nss-mdns}
  15233. (@pxref{Name Service Switch, mDNS}).
  15234. @end defvr
  15235. The @code{%desktop-services} variable can be used as the @code{services}
  15236. field of an @code{operating-system} declaration (@pxref{operating-system
  15237. Reference, @code{services}}).
  15238. Additionally, the @code{gnome-desktop-service-type},
  15239. @code{xfce-desktop-service}, @code{mate-desktop-service-type},
  15240. @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
  15241. procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
  15242. ``add GNOME'' means that system-level services like the backlight adjustment
  15243. helpers and the power management utilities are added to the system, extending
  15244. @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
  15245. elevated privileges on a limited number of special-purpose system interfaces.
  15246. Additionally, adding a service made by @code{gnome-desktop-service-type} adds
  15247. the GNOME metapackage to the system profile. Likewise, adding the Xfce
  15248. service not only adds the @code{xfce} metapackage to the system profile, but
  15249. it also gives the Thunar file manager the ability to open a ``root-mode'' file
  15250. management window, if the user authenticates using the administrator's
  15251. password via the standard polkit graphical interface. To ``add MATE'' means
  15252. that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
  15253. to operate with elevated privileges on a limited number of special-purpose
  15254. system interfaces. Additionally, adding a service of type
  15255. @code{mate-desktop-service-type} adds the MATE metapackage to the system
  15256. profile. ``Adding Enlightenment'' means that @code{dbus} is extended
  15257. appropriately, and several of Enlightenment's binaries are set as setuid,
  15258. allowing Enlightenment's screen locker and other functionality to work as
  15259. expected.
  15260. The desktop environments in Guix use the Xorg display server by
  15261. default. If you'd like to use the newer display server protocol
  15262. called Wayland, you need to use the @code{sddm-service} instead of
  15263. GDM as the graphical login manager. You should then
  15264. select the ``GNOME (Wayland)'' session in SDDM@. Alternatively you can
  15265. also try starting GNOME on Wayland manually from a TTY with the
  15266. command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
  15267. gnome-session``. Currently only GNOME has support for Wayland.
  15268. @defvr {Scheme Variable} gnome-desktop-service-type
  15269. This is the type of the service that adds the @uref{https://www.gnome.org,
  15270. GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
  15271. object (see below).
  15272. This service adds the @code{gnome} package to the system profile, and extends
  15273. polkit with the actions from @code{gnome-settings-daemon}.
  15274. @end defvr
  15275. @deftp {Data Type} gnome-desktop-configuration
  15276. Configuration record for the GNOME desktop environment.
  15277. @table @asis
  15278. @item @code{gnome} (default: @code{gnome})
  15279. The GNOME package to use.
  15280. @end table
  15281. @end deftp
  15282. @defvr {Scheme Variable} xfce-desktop-service-type
  15283. This is the type of a service to run the @uref{Xfce, https://xfce.org/}
  15284. desktop environment. Its value is an @code{xfce-desktop-configuration} object
  15285. (see below).
  15286. This service adds the @code{xfce} package to the system profile, and
  15287. extends polkit with the ability for @code{thunar} to manipulate the file
  15288. system as root from within a user session, after the user has authenticated
  15289. with the administrator's password.
  15290. Note that @code{xfce4-panel} and its plugin packages should be installed in
  15291. the same profile to ensure compatibility. When using this service, you should
  15292. add extra plugins (@code{xfce4-whiskermenu-plugin},
  15293. @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
  15294. @code{operating-system}.
  15295. @end defvr
  15296. @deftp {Data Type} xfce-desktop-configuration
  15297. Configuration record for the Xfce desktop environment.
  15298. @table @asis
  15299. @item @code{xfce} (default: @code{xfce})
  15300. The Xfce package to use.
  15301. @end table
  15302. @end deftp
  15303. @deffn {Scheme Variable} mate-desktop-service-type
  15304. This is the type of the service that runs the @uref{https://mate-desktop.org/,
  15305. MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
  15306. object (see below).
  15307. This service adds the @code{mate} package to the system
  15308. profile, and extends polkit with the actions from
  15309. @code{mate-settings-daemon}.
  15310. @end deffn
  15311. @deftp {Data Type} mate-desktop-configuration
  15312. Configuration record for the MATE desktop environment.
  15313. @table @asis
  15314. @item @code{mate} (default: @code{mate})
  15315. The MATE package to use.
  15316. @end table
  15317. @end deftp
  15318. @deffn {Scheme Variable} lxqt-desktop-service-type
  15319. This is the type of the service that runs the @uref{https://lxqt.github.io,
  15320. LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
  15321. object (see below).
  15322. This service adds the @code{lxqt} package to the system
  15323. profile.
  15324. @end deffn
  15325. @deftp {Data Type} lxqt-desktop-configuration
  15326. Configuration record for the LXQt desktop environment.
  15327. @table @asis
  15328. @item @code{lxqt} (default: @code{lxqt})
  15329. The LXQT package to use.
  15330. @end table
  15331. @end deftp
  15332. @deffn {Scheme Variable} enlightenment-desktop-service-type
  15333. Return a service that adds the @code{enlightenment} package to the system
  15334. profile, and extends dbus with actions from @code{efl}.
  15335. @end deffn
  15336. @deftp {Data Type} enlightenment-desktop-service-configuration
  15337. @table @asis
  15338. @item @code{enlightenment} (default: @code{enlightenment})
  15339. The enlightenment package to use.
  15340. @end table
  15341. @end deftp
  15342. Because the GNOME, Xfce and MATE desktop services pull in so many packages,
  15343. the default @code{%desktop-services} variable doesn't include any of
  15344. them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
  15345. @code{%desktop-services} in the @code{services} field of your
  15346. @code{operating-system}:
  15347. @lisp
  15348. (use-modules (gnu))
  15349. (use-service-modules desktop)
  15350. (operating-system
  15351. ...
  15352. ;; cons* adds items to the list given as its last argument.
  15353. (services (cons* (service gnome-desktop-service-type)
  15354. (service xfce-desktop-service)
  15355. %desktop-services))
  15356. ...)
  15357. @end lisp
  15358. These desktop environments will then be available as options in the
  15359. graphical login window.
  15360. The actual service definitions included in @code{%desktop-services} and
  15361. provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
  15362. are described below.
  15363. @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
  15364. Return a service that runs the ``system bus'', using @var{dbus}, with
  15365. support for @var{services}.
  15366. @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
  15367. facility. Its system bus is used to allow system services to communicate
  15368. and to be notified of system-wide events.
  15369. @var{services} must be a list of packages that provide an
  15370. @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
  15371. and policy files. For example, to allow avahi-daemon to use the system bus,
  15372. @var{services} must be equal to @code{(list avahi)}.
  15373. @end deffn
  15374. @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
  15375. Return a service that runs the @code{elogind} login and
  15376. seat management daemon. @uref{https://github.com/elogind/elogind,
  15377. Elogind} exposes a D-Bus interface that can be used to know which users
  15378. are logged in, know what kind of sessions they have open, suspend the
  15379. system, inhibit system suspend, reboot the system, and other tasks.
  15380. Elogind handles most system-level power events for a computer, for
  15381. example suspending the system when a lid is closed, or shutting it down
  15382. when the power button is pressed.
  15383. The @var{config} keyword argument specifies the configuration for
  15384. elogind, and should be the result of an @code{(elogind-configuration
  15385. (@var{parameter} @var{value})...)} invocation. Available parameters and
  15386. their default values are:
  15387. @table @code
  15388. @item kill-user-processes?
  15389. @code{#f}
  15390. @item kill-only-users
  15391. @code{()}
  15392. @item kill-exclude-users
  15393. @code{("root")}
  15394. @item inhibit-delay-max-seconds
  15395. @code{5}
  15396. @item handle-power-key
  15397. @code{poweroff}
  15398. @item handle-suspend-key
  15399. @code{suspend}
  15400. @item handle-hibernate-key
  15401. @code{hibernate}
  15402. @item handle-lid-switch
  15403. @code{suspend}
  15404. @item handle-lid-switch-docked
  15405. @code{ignore}
  15406. @item handle-lid-switch-external-power
  15407. @code{ignore}
  15408. @item power-key-ignore-inhibited?
  15409. @code{#f}
  15410. @item suspend-key-ignore-inhibited?
  15411. @code{#f}
  15412. @item hibernate-key-ignore-inhibited?
  15413. @code{#f}
  15414. @item lid-switch-ignore-inhibited?
  15415. @code{#t}
  15416. @item holdoff-timeout-seconds
  15417. @code{30}
  15418. @item idle-action
  15419. @code{ignore}
  15420. @item idle-action-seconds
  15421. @code{(* 30 60)}
  15422. @item runtime-directory-size-percent
  15423. @code{10}
  15424. @item runtime-directory-size
  15425. @code{#f}
  15426. @item remove-ipc?
  15427. @code{#t}
  15428. @item suspend-state
  15429. @code{("mem" "standby" "freeze")}
  15430. @item suspend-mode
  15431. @code{()}
  15432. @item hibernate-state
  15433. @code{("disk")}
  15434. @item hibernate-mode
  15435. @code{("platform" "shutdown")}
  15436. @item hybrid-sleep-state
  15437. @code{("disk")}
  15438. @item hybrid-sleep-mode
  15439. @code{("suspend" "platform" "shutdown")}
  15440. @end table
  15441. @end deffn
  15442. @deffn {Scheme Procedure} accountsservice-service @
  15443. [#:accountsservice @var{accountsservice}]
  15444. Return a service that runs AccountsService, a system service that can
  15445. list available accounts, change their passwords, and so on.
  15446. AccountsService integrates with PolicyKit to enable unprivileged users
  15447. to acquire the capability to modify their system configuration.
  15448. @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
  15449. accountsservice web site} for more information.
  15450. The @var{accountsservice} keyword argument is the @code{accountsservice}
  15451. package to expose as a service.
  15452. @end deffn
  15453. @deffn {Scheme Procedure} polkit-service @
  15454. [#:polkit @var{polkit}]
  15455. Return a service that runs the
  15456. @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
  15457. management service}, which allows system administrators to grant access to
  15458. privileged operations in a structured way. By querying the Polkit service, a
  15459. privileged system component can know when it should grant additional
  15460. capabilities to ordinary users. For example, an ordinary user can be granted
  15461. the capability to suspend the system if the user is logged in locally.
  15462. @end deffn
  15463. @defvr {Scheme Variable} polkit-wheel-service
  15464. Service that adds the @code{wheel} group as admins to the Polkit
  15465. service. This makes it so that users in the @code{wheel} group are queried
  15466. for their own passwords when performing administrative actions instead of
  15467. @code{root}'s, similar to the behaviour used by @code{sudo}.
  15468. @end defvr
  15469. @defvr {Scheme Variable} upower-service-type
  15470. Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
  15471. system-wide monitor for power consumption and battery levels, with the given
  15472. configuration settings.
  15473. It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
  15474. notably used by GNOME.
  15475. @end defvr
  15476. @deftp {Data Type} upower-configuration
  15477. Data type representation the configuration for UPower.
  15478. @table @asis
  15479. @item @code{upower} (default: @var{upower})
  15480. Package to use for @code{upower}.
  15481. @item @code{watts-up-pro?} (default: @code{#f})
  15482. Enable the Watts Up Pro device.
  15483. @item @code{poll-batteries?} (default: @code{#t})
  15484. Enable polling the kernel for battery level changes.
  15485. @item @code{ignore-lid?} (default: @code{#f})
  15486. Ignore the lid state, this can be useful if it's incorrect on a device.
  15487. @item @code{use-percentage-for-policy?} (default: @code{#f})
  15488. Whether battery percentage based policy should be used. The default is to use
  15489. the time left, change to @code{#t} to use the percentage.
  15490. @item @code{percentage-low} (default: @code{10})
  15491. When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
  15492. at which the battery is considered low.
  15493. @item @code{percentage-critical} (default: @code{3})
  15494. When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
  15495. at which the battery is considered critical.
  15496. @item @code{percentage-action} (default: @code{2})
  15497. When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
  15498. at which action will be taken.
  15499. @item @code{time-low} (default: @code{1200})
  15500. When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
  15501. seconds at which the battery is considered low.
  15502. @item @code{time-critical} (default: @code{300})
  15503. When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
  15504. seconds at which the battery is considered critical.
  15505. @item @code{time-action} (default: @code{120})
  15506. When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
  15507. seconds at which action will be taken.
  15508. @item @code{critical-power-action} (default: @code{'hybrid-sleep})
  15509. The action taken when @code{percentage-action} or @code{time-action} is
  15510. reached (depending on the configuration of @code{use-percentage-for-policy?}).
  15511. Possible values are:
  15512. @itemize @bullet
  15513. @item
  15514. @code{'power-off}
  15515. @item
  15516. @code{'hibernate}
  15517. @item
  15518. @code{'hybrid-sleep}.
  15519. @end itemize
  15520. @end table
  15521. @end deftp
  15522. @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
  15523. Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
  15524. UDisks}, a @dfn{disk management} daemon that provides user interfaces
  15525. with notifications and ways to mount/unmount disks. Programs that talk
  15526. to UDisks include the @command{udisksctl} command, part of UDisks, and
  15527. GNOME Disks. Note that Udisks relies on the @command{mount} command, so
  15528. it will only be able to use the file-system utilities installed in the
  15529. system profile. For example if you want to be able to mount NTFS
  15530. file-systems in read and write fashion, you'll need to have
  15531. @code{ntfs-3g} installed system-wide.
  15532. @end deffn
  15533. @deffn {Scheme Variable} colord-service-type
  15534. This is the type of the service that runs @command{colord}, a system
  15535. service with a D-Bus
  15536. interface to manage the color profiles of input and output devices such as
  15537. screens and scanners. It is notably used by the GNOME Color Manager graphical
  15538. tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
  15539. site} for more information.
  15540. @end deffn
  15541. @cindex scanner access
  15542. @defvr {Scheme Variable} sane-service-type
  15543. This service provides access to scanners @i{via}
  15544. @uref{http://www.sane-project.org, SANE} by installing the necessary
  15545. udev rules. It is included in @code{%desktop-services} (@pxref{Desktop
  15546. Services}) and relies by default on @code{sane-backends-minimal} package
  15547. (see below) for hardware support.
  15548. @end defvr
  15549. @defvr {Scheme Variable} sane-backends-minimal
  15550. The default package which the @code{sane-service-type} installs. It
  15551. supports many recent scanners.
  15552. @end defvr
  15553. @defvr {Scheme Variable} sane-backends
  15554. This package includes support for all scanners that
  15555. @code{sane-backends-minimal} supports, plus older Hewlett-Packard
  15556. scanners supported by @code{hplip} package. In order to use this on
  15557. a system which relies on @code{%desktop-services}, you may use
  15558. @code{modify-services} (@pxref{Service Reference,
  15559. @code{modify-services}}) as illustrated below:
  15560. @lisp
  15561. (use-modules (gnu))
  15562. (use-service-modules
  15563. @dots{}
  15564. desktop)
  15565. (use-package-modules
  15566. @dots{}
  15567. scanner)
  15568. (define %my-desktop-services
  15569. ;; List of desktop services that supports a broader range of scanners.
  15570. (modify-services %desktop-services
  15571. (sane-service-type _ => sane-backends)))
  15572. (operating-system
  15573. @dots{}
  15574. (services %my-desktop-services)
  15575. @end lisp
  15576. @end defvr
  15577. @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
  15578. Return a configuration allowing an application to access GeoClue
  15579. location data. @var{name} is the Desktop ID of the application, without
  15580. the @code{.desktop} part. If @var{allowed?} is true, the application
  15581. will have access to location information by default. The boolean
  15582. @var{system?} value indicates whether an application is a system component
  15583. or not. Finally @var{users} is a list of UIDs of all users for which
  15584. this application is allowed location info access. An empty users list
  15585. means that all users are allowed.
  15586. @end deffn
  15587. @defvr {Scheme Variable} %standard-geoclue-applications
  15588. The standard list of well-known GeoClue application configurations,
  15589. granting authority to the GNOME date-and-time utility to ask for the
  15590. current location in order to set the time zone, and allowing the
  15591. IceCat and Epiphany web browsers to request location information.
  15592. IceCat and Epiphany both query the user before allowing a web page to
  15593. know the user's location.
  15594. @end defvr
  15595. @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
  15596. [#:whitelist '()] @
  15597. [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
  15598. [#:submit-data? #f]
  15599. [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
  15600. [#:submission-nick "geoclue"] @
  15601. [#:applications %standard-geoclue-applications]
  15602. Return a service that runs the GeoClue location service. This service
  15603. provides a D-Bus interface to allow applications to request access to a
  15604. user's physical location, and optionally to add information to online
  15605. location databases. See
  15606. @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
  15607. web site} for more information.
  15608. @end deffn
  15609. @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
  15610. [@w{#:auto-enable? #f}]
  15611. Return a service that runs the @command{bluetoothd} daemon, which
  15612. manages all the Bluetooth devices and provides a number of D-Bus
  15613. interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
  15614. powered automatically at boot, which can be useful when using a
  15615. bluetooth keyboard or mouse.
  15616. Users need to be in the @code{lp} group to access the D-Bus service.
  15617. @end deffn
  15618. @defvr {Scheme Variable} gnome-keyring-service-type
  15619. This is the type of the service that adds the
  15620. @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
  15621. value is a @code{gnome-keyring-configuration} object (see below).
  15622. This service adds the @code{gnome-keyring} package to the system profile
  15623. and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
  15624. a user's login keyring when they log in or setting its password with passwd.
  15625. @end defvr
  15626. @deftp {Data Type} gnome-keyring-configuration
  15627. Configuration record for the GNOME Keyring service.
  15628. @table @asis
  15629. @item @code{keyring} (default: @code{gnome-keyring})
  15630. The GNOME keyring package to use.
  15631. @item @code{pam-services}
  15632. A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
  15633. services to extend, where @var{service} is the name of an existing
  15634. service to extend and @var{kind} is one of @code{login} or
  15635. @code{passwd}.
  15636. If @code{login} is given, it adds an optional
  15637. @code{pam_gnome_keyring.so} to the auth block without arguments and to
  15638. the session block with @code{auto_start}. If @code{passwd} is given, it
  15639. adds an optional @code{pam_gnome_keyring.so} to the password block
  15640. without arguments.
  15641. By default, this field contains ``gdm-password'' with the value @code{login}
  15642. and ``passwd'' is with the value @code{passwd}.
  15643. @end table
  15644. @end deftp
  15645. @node Sound Services
  15646. @subsection Sound Services
  15647. @cindex sound support
  15648. @cindex ALSA
  15649. @cindex PulseAudio, sound support
  15650. The @code{(gnu services sound)} module provides a service to configure the
  15651. Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
  15652. preferred ALSA output driver.
  15653. @deffn {Scheme Variable} alsa-service-type
  15654. This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
  15655. Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
  15656. configuration file. The value for this type is a @command{alsa-configuration}
  15657. record as in this example:
  15658. @lisp
  15659. (service alsa-service-type)
  15660. @end lisp
  15661. See below for details about @code{alsa-configuration}.
  15662. @end deffn
  15663. @deftp {Data Type} alsa-configuration
  15664. Data type representing the configuration for @code{alsa-service}.
  15665. @table @asis
  15666. @item @code{alsa-plugins} (default: @var{alsa-plugins})
  15667. @code{alsa-plugins} package to use.
  15668. @item @code{pulseaudio?} (default: @var{#t})
  15669. Whether ALSA applications should transparently be made to use the
  15670. @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
  15671. Using PulseAudio allows you to run several sound-producing applications
  15672. at the same time and to individual control them @i{via}
  15673. @command{pavucontrol}, among other things.
  15674. @item @code{extra-options} (default: @var{""})
  15675. String to append to the @file{/etc/asound.conf} file.
  15676. @end table
  15677. @end deftp
  15678. Individual users who want to override the system configuration of ALSA can do
  15679. it with the @file{~/.asoundrc} file:
  15680. @example
  15681. # In guix, we have to specify the absolute path for plugins.
  15682. pcm_type.jack @{
  15683. lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
  15684. @}
  15685. # Routing ALSA to jack:
  15686. # <http://jackaudio.org/faq/routing_alsa.html>.
  15687. pcm.rawjack @{
  15688. type jack
  15689. playback_ports @{
  15690. 0 system:playback_1
  15691. 1 system:playback_2
  15692. @}
  15693. capture_ports @{
  15694. 0 system:capture_1
  15695. 1 system:capture_2
  15696. @}
  15697. @}
  15698. pcm.!default @{
  15699. type plug
  15700. slave @{
  15701. pcm "rawjack"
  15702. @}
  15703. @}
  15704. @end example
  15705. See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
  15706. details.
  15707. @deffn {Scheme Variable} pulseaudio-service-type
  15708. This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
  15709. sound server. It exists to allow system overrides of the default settings
  15710. via @code{pulseaudio-configuration}, see below.
  15711. @quotation Warning
  15712. This service overrides per-user configuration files. If you want
  15713. PulseAudio to honor configuration files in @file{~/.config/pulse} you
  15714. have to unset the environment variables @env{PULSE_CONFIG} and
  15715. @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
  15716. @end quotation
  15717. @quotation Warning
  15718. This service on its own does not ensure, that the @code{pulseaudio} package
  15719. exists on your machine. It merely adds configuration files for it, as
  15720. detailed below. In the (admittedly unlikely) case, that you find yourself
  15721. without a @code{pulseaudio} package, consider enabling it through the
  15722. @code{alsa-service-type} above.
  15723. @end quotation
  15724. @end deffn
  15725. @deftp {Data Type} pulseaudio-configuration
  15726. Data type representing the configuration for @code{pulseaudio-service}.
  15727. @table @asis
  15728. @item @code{client-conf} (default: @code{'()})
  15729. List of settings to set in @file{client.conf}.
  15730. Accepts a list of strings or a symbol-value pairs. A string will be
  15731. inserted as-is with a newline added. A pair will be formatted as
  15732. ``key = value'', again with a newline added.
  15733. @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
  15734. List of settings to set in @file{daemon.conf}, formatted just like
  15735. @var{client-conf}.
  15736. @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
  15737. Script file to use as @file{default.pa}.
  15738. @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
  15739. Script file to use as @file{system.pa}.
  15740. @end table
  15741. @end deftp
  15742. @deffn {Scheme Variable} ladspa-service-type
  15743. This service sets the @var{LADSPA_PATH} variable, so that programs, which
  15744. respect it, e.g. PulseAudio, can load LADSPA plugins.
  15745. The following example will setup the service to enable modules from the
  15746. @code{swh-plugins} package:
  15747. @lisp
  15748. (service ladspa-service-type
  15749. (ladspa-configuration (plugins (list swh-plugins))))
  15750. @end lisp
  15751. See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
  15752. details.
  15753. @end deffn
  15754. @node Database Services
  15755. @subsection Database Services
  15756. @cindex database
  15757. @cindex SQL
  15758. The @code{(gnu services databases)} module provides the following services.
  15759. @subsubheading PostgreSQL
  15760. The following example describes a PostgreSQL service with the default
  15761. configuration.
  15762. @lisp
  15763. (service postgresql-service-type
  15764. (postgresql-configuration
  15765. (postgresql postgresql-10)))
  15766. @end lisp
  15767. If the services fails to start, it may be due to an incompatible
  15768. cluster already present in @var{data-directory}. Adjust it (or, if you
  15769. don't need the cluster anymore, delete @var{data-directory}), then
  15770. restart the service.
  15771. Peer authentication is used by default and the @code{postgres} user
  15772. account has no shell, which prevents the direct execution of @code{psql}
  15773. commands as this user. To use @code{psql}, you can temporarily log in
  15774. as @code{postgres} using a shell, create a PostgreSQL superuser with the
  15775. same name as one of the system users and then create the associated
  15776. database.
  15777. @example
  15778. sudo -u postgres -s /bin/sh
  15779. createuser --interactive
  15780. createdb $MY_USER_LOGIN # Replace appropriately.
  15781. @end example
  15782. @deftp {Data Type} postgresql-configuration
  15783. Data type representing the configuration for the
  15784. @code{postgresql-service-type}.
  15785. @table @asis
  15786. @item @code{postgresql}
  15787. PostgreSQL package to use for the service.
  15788. @item @code{port} (default: @code{5432})
  15789. Port on which PostgreSQL should listen.
  15790. @item @code{locale} (default: @code{"en_US.utf8"})
  15791. Locale to use as the default when creating the database cluster.
  15792. @item @code{config-file} (default: @code{(postgresql-config-file)})
  15793. The configuration file to use when running PostgreSQL@. The default
  15794. behaviour uses the postgresql-config-file record with the default values
  15795. for the fields.
  15796. @item @code{log-directory} (default: @code{"/var/log/postgresql"})
  15797. The directory where @command{pg_ctl} output will be written in a file
  15798. named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
  15799. configuration errors for instance.
  15800. @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
  15801. Directory in which to store the data.
  15802. @item @code{extension-packages} (default: @code{'()})
  15803. @cindex postgresql extension-packages
  15804. Additional extensions are loaded from packages listed in
  15805. @var{extension-packages}. Extensions are available at runtime. For instance,
  15806. to create a geographic database using the @code{postgis} extension, a user can
  15807. configure the postgresql-service as in this example:
  15808. @cindex postgis
  15809. @lisp
  15810. (use-package-modules databases geo)
  15811. (operating-system
  15812. ...
  15813. ;; postgresql is required to run `psql' but postgis is not required for
  15814. ;; proper operation.
  15815. (packages (cons* postgresql %base-packages))
  15816. (services
  15817. (cons*
  15818. (service postgresql-service-type
  15819. (postgresql-configuration
  15820. (postgresql postgresql-10)
  15821. (extension-packages (list postgis))))
  15822. %base-services)))
  15823. @end lisp
  15824. Then the extension becomes visible and you can initialise an empty geographic
  15825. database in this way:
  15826. @example
  15827. psql -U postgres
  15828. > create database postgistest;
  15829. > \connect postgistest;
  15830. > create extension postgis;
  15831. > create extension postgis_topology;
  15832. @end example
  15833. There is no need to add this field for contrib extensions such as hstore or
  15834. dblink as they are already loadable by postgresql. This field is only
  15835. required to add extensions provided by other packages.
  15836. @end table
  15837. @end deftp
  15838. @deftp {Data Type} postgresql-config-file
  15839. Data type representing the PostgreSQL configuration file. As shown in
  15840. the following example, this can be used to customize the configuration
  15841. of PostgreSQL@. Note that you can use any G-expression or filename in
  15842. place of this record, if you already have a configuration file you'd
  15843. like to use for example.
  15844. @lisp
  15845. (service postgresql-service-type
  15846. (postgresql-configuration
  15847. (config-file
  15848. (postgresql-config-file
  15849. (log-destination "stderr")
  15850. (hba-file
  15851. (plain-file "pg_hba.conf"
  15852. "
  15853. local all all trust
  15854. host all all 127.0.0.1/32 md5
  15855. host all all ::1/128 md5"))
  15856. (extra-config
  15857. '(("session_preload_libraries" "auto_explain")
  15858. ("random_page_cost" 2)
  15859. ("auto_explain.log_min_duration" "100 ms")
  15860. ("work_mem" "500 MB")
  15861. ("logging_collector" #t)
  15862. ("log_directory" "/var/log/postgresql")))))))
  15863. @end lisp
  15864. @table @asis
  15865. @item @code{log-destination} (default: @code{"syslog"})
  15866. The logging method to use for PostgreSQL@. Multiple values are accepted,
  15867. separated by commas.
  15868. @item @code{hba-file} (default: @code{%default-postgres-hba})
  15869. Filename or G-expression for the host-based authentication
  15870. configuration.
  15871. @item @code{ident-file} (default: @code{%default-postgres-ident})
  15872. Filename or G-expression for the user name mapping configuration.
  15873. @item @code{socket-directory} (default: @code{"/var/run/postgresql"})
  15874. Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
  15875. is to listen for connections from client applications. If set to
  15876. @code{#false} PostgreSQL does not listen on any Unix-domain sockets, in
  15877. which case only TCP/IP sockets can be used to connect to the server.
  15878. @item @code{extra-config} (default: @code{'()})
  15879. List of additional keys and values to include in the PostgreSQL config
  15880. file. Each entry in the list should be a list where the first element
  15881. is the key, and the remaining elements are the values.
  15882. The values can be numbers, booleans or strings and will be mapped to
  15883. PostgreSQL parameters types @code{Boolean}, @code{String},
  15884. @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
  15885. @uref{https://www.postgresql.org/docs/current/config-setting.html,
  15886. here}.
  15887. @end table
  15888. @end deftp
  15889. @deffn {Scheme Variable} postgresql-role-service-type
  15890. This service allows to create PostgreSQL roles and databases after
  15891. PostgreSQL service start. Here is an example of its use.
  15892. @lisp
  15893. (service postgresql-role-service-type
  15894. (postgresql-role-configuration
  15895. (roles
  15896. (list (postgresql-role
  15897. (name "test")
  15898. (create-database? #t))))))
  15899. @end lisp
  15900. This service can be extended with extra roles, as in this
  15901. example:
  15902. @lisp
  15903. (service-extension postgresql-role-service-type
  15904. (const (postgresql-role
  15905. (name "alice")
  15906. (create-database? #t))))
  15907. @end lisp
  15908. @end deffn
  15909. @deftp {Data Type} postgresql-role
  15910. PostgreSQL manages database access permissions using the concept of
  15911. roles. A role can be thought of as either a database user, or a group
  15912. of database users, depending on how the role is set up. Roles can own
  15913. database objects (for example, tables) and can assign privileges on
  15914. those objects to other roles to control who has access to which objects.
  15915. @table @asis
  15916. @item @code{name}
  15917. The role name.
  15918. @item @code{permissions} (default: @code{'(createdb login)})
  15919. The role permissions list. Supported permissions are @code{bypassrls},
  15920. @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
  15921. @code{superuser}.
  15922. @item @code{create-database?} (default: @code{#f})
  15923. Whether to create a database with the same name as the role.
  15924. @end table
  15925. @end deftp
  15926. @deftp {Data Type} postgresql-role-configuration
  15927. Data type representing the configuration of
  15928. @var{postgresql-role-service-type}.
  15929. @table @asis
  15930. @item @code{host} (default: @code{"/var/run/postgresql"})
  15931. The PostgreSQL host to connect to.
  15932. @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
  15933. File name of the log file.
  15934. @item @code{roles} (default: @code{'()})
  15935. The initial PostgreSQL roles to create.
  15936. @end table
  15937. @end deftp
  15938. @subsubheading MariaDB/MySQL
  15939. @defvr {Scheme Variable} mysql-service-type
  15940. This is the service type for a MySQL or MariaDB database server. Its value
  15941. is a @code{mysql-configuration} object that specifies which package to use,
  15942. as well as various settings for the @command{mysqld} daemon.
  15943. @end defvr
  15944. @deftp {Data Type} mysql-configuration
  15945. Data type representing the configuration of @var{mysql-service-type}.
  15946. @table @asis
  15947. @item @code{mysql} (default: @var{mariadb})
  15948. Package object of the MySQL database server, can be either @var{mariadb}
  15949. or @var{mysql}.
  15950. For MySQL, a temporary root password will be displayed at activation time.
  15951. For MariaDB, the root password is empty.
  15952. @item @code{bind-address} (default: @code{"127.0.0.1"})
  15953. The IP on which to listen for network connections. Use @code{"0.0.0.0"}
  15954. to bind to all available network interfaces.
  15955. @item @code{port} (default: @code{3306})
  15956. TCP port on which the database server listens for incoming connections.
  15957. @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
  15958. Socket file to use for local (non-network) connections.
  15959. @item @code{extra-content} (default: @code{""})
  15960. Additional settings for the @file{my.cnf} configuration file.
  15961. @item @code{auto-upgrade?} (default: @code{#t})
  15962. Whether to automatically run @command{mysql_upgrade} after starting the
  15963. service. This is necessary to upgrade the @dfn{system schema} after
  15964. ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
  15965. be disabled if you would rather do that manually.
  15966. @end table
  15967. @end deftp
  15968. @subsubheading Memcached
  15969. @defvr {Scheme Variable} memcached-service-type
  15970. This is the service type for the @uref{https://memcached.org/,
  15971. Memcached} service, which provides a distributed in memory cache. The
  15972. value for the service type is a @code{memcached-configuration} object.
  15973. @end defvr
  15974. @lisp
  15975. (service memcached-service-type)
  15976. @end lisp
  15977. @deftp {Data Type} memcached-configuration
  15978. Data type representing the configuration of memcached.
  15979. @table @asis
  15980. @item @code{memcached} (default: @code{memcached})
  15981. The Memcached package to use.
  15982. @item @code{interfaces} (default: @code{'("0.0.0.0")})
  15983. Network interfaces on which to listen.
  15984. @item @code{tcp-port} (default: @code{11211})
  15985. Port on which to accept connections.
  15986. @item @code{udp-port} (default: @code{11211})
  15987. Port on which to accept UDP connections on, a value of 0 will disable
  15988. listening on a UDP socket.
  15989. @item @code{additional-options} (default: @code{'()})
  15990. Additional command line options to pass to @code{memcached}.
  15991. @end table
  15992. @end deftp
  15993. @subsubheading Redis
  15994. @defvr {Scheme Variable} redis-service-type
  15995. This is the service type for the @uref{https://redis.io/, Redis}
  15996. key/value store, whose value is a @code{redis-configuration} object.
  15997. @end defvr
  15998. @deftp {Data Type} redis-configuration
  15999. Data type representing the configuration of redis.
  16000. @table @asis
  16001. @item @code{redis} (default: @code{redis})
  16002. The Redis package to use.
  16003. @item @code{bind} (default: @code{"127.0.0.1"})
  16004. Network interface on which to listen.
  16005. @item @code{port} (default: @code{6379})
  16006. Port on which to accept connections on, a value of 0 will disable
  16007. listening on a TCP socket.
  16008. @item @code{working-directory} (default: @code{"/var/lib/redis"})
  16009. Directory in which to store the database and related files.
  16010. @end table
  16011. @end deftp
  16012. @node Mail Services
  16013. @subsection Mail Services
  16014. @cindex mail
  16015. @cindex email
  16016. The @code{(gnu services mail)} module provides Guix service definitions
  16017. for email services: IMAP, POP3, and LMTP servers, as well as mail
  16018. transport agents (MTAs). Lots of acronyms! These services are detailed
  16019. in the subsections below.
  16020. @subsubheading Dovecot Service
  16021. @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
  16022. Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
  16023. @end deffn
  16024. By default, Dovecot does not need much configuration; the default
  16025. configuration object created by @code{(dovecot-configuration)} will
  16026. suffice if your mail is delivered to @code{~/Maildir}. A self-signed
  16027. certificate will be generated for TLS-protected connections, though
  16028. Dovecot will also listen on cleartext ports by default. There are a
  16029. number of options, though, which mail administrators might need to change,
  16030. and as is the case with other services, Guix allows the system
  16031. administrator to specify these parameters via a uniform Scheme interface.
  16032. For example, to specify that mail is located at @code{maildir~/.mail},
  16033. one would instantiate the Dovecot service like this:
  16034. @lisp
  16035. (dovecot-service #:config
  16036. (dovecot-configuration
  16037. (mail-location "maildir:~/.mail")))
  16038. @end lisp
  16039. The available configuration parameters follow. Each parameter
  16040. definition is preceded by its type; for example, @samp{string-list foo}
  16041. indicates that the @code{foo} parameter should be specified as a list of
  16042. strings. There is also a way to specify the configuration as a string,
  16043. if you have an old @code{dovecot.conf} file that you want to port over
  16044. from some other system; see the end for more details.
  16045. @c The following documentation was initially generated by
  16046. @c (generate-documentation) in (gnu services mail). Manually maintained
  16047. @c documentation is better, so we shouldn't hesitate to edit below as
  16048. @c needed. However if the change you want to make to this documentation
  16049. @c can be done in an automated way, it's probably easier to change
  16050. @c (generate-documentation) than to make it below and have to deal with
  16051. @c the churn as dovecot updates.
  16052. Available @code{dovecot-configuration} fields are:
  16053. @deftypevr {@code{dovecot-configuration} parameter} package dovecot
  16054. The dovecot package.
  16055. @end deftypevr
  16056. @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
  16057. A list of IPs or hosts where to listen for connections. @samp{*}
  16058. listens on all IPv4 interfaces, @samp{::} listens on all IPv6
  16059. interfaces. If you want to specify non-default ports or anything more
  16060. complex, customize the address and port fields of the
  16061. @samp{inet-listener} of the specific services you are interested in.
  16062. @end deftypevr
  16063. @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
  16064. List of protocols we want to serve. Available protocols include
  16065. @samp{imap}, @samp{pop3}, and @samp{lmtp}.
  16066. Available @code{protocol-configuration} fields are:
  16067. @deftypevr {@code{protocol-configuration} parameter} string name
  16068. The name of the protocol.
  16069. @end deftypevr
  16070. @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
  16071. UNIX socket path to the master authentication server to find users.
  16072. This is used by imap (for shared users) and lda.
  16073. It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
  16074. @end deftypevr
  16075. @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
  16076. Space separated list of plugins to load.
  16077. @end deftypevr
  16078. @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
  16079. Maximum number of IMAP connections allowed for a user from each IP
  16080. address. NOTE: The username is compared case-sensitively.
  16081. Defaults to @samp{10}.
  16082. @end deftypevr
  16083. @end deftypevr
  16084. @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
  16085. List of services to enable. Available services include @samp{imap},
  16086. @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
  16087. @samp{lmtp}.
  16088. Available @code{service-configuration} fields are:
  16089. @deftypevr {@code{service-configuration} parameter} string kind
  16090. The service kind. Valid values include @code{director},
  16091. @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
  16092. @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
  16093. @code{tcpwrap}, @code{quota-warning}, or anything else.
  16094. @end deftypevr
  16095. @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
  16096. Listeners for the service. A listener is either a
  16097. @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
  16098. an @code{inet-listener-configuration}.
  16099. Defaults to @samp{()}.
  16100. Available @code{unix-listener-configuration} fields are:
  16101. @deftypevr {@code{unix-listener-configuration} parameter} string path
  16102. Path to the file, relative to @code{base-dir} field. This is also used as
  16103. the section name.
  16104. @end deftypevr
  16105. @deftypevr {@code{unix-listener-configuration} parameter} string mode
  16106. The access mode for the socket.
  16107. Defaults to @samp{"0600"}.
  16108. @end deftypevr
  16109. @deftypevr {@code{unix-listener-configuration} parameter} string user
  16110. The user to own the socket.
  16111. Defaults to @samp{""}.
  16112. @end deftypevr
  16113. @deftypevr {@code{unix-listener-configuration} parameter} string group
  16114. The group to own the socket.
  16115. Defaults to @samp{""}.
  16116. @end deftypevr
  16117. Available @code{fifo-listener-configuration} fields are:
  16118. @deftypevr {@code{fifo-listener-configuration} parameter} string path
  16119. Path to the file, relative to @code{base-dir} field. This is also used as
  16120. the section name.
  16121. @end deftypevr
  16122. @deftypevr {@code{fifo-listener-configuration} parameter} string mode
  16123. The access mode for the socket.
  16124. Defaults to @samp{"0600"}.
  16125. @end deftypevr
  16126. @deftypevr {@code{fifo-listener-configuration} parameter} string user
  16127. The user to own the socket.
  16128. Defaults to @samp{""}.
  16129. @end deftypevr
  16130. @deftypevr {@code{fifo-listener-configuration} parameter} string group
  16131. The group to own the socket.
  16132. Defaults to @samp{""}.
  16133. @end deftypevr
  16134. Available @code{inet-listener-configuration} fields are:
  16135. @deftypevr {@code{inet-listener-configuration} parameter} string protocol
  16136. The protocol to listen for.
  16137. @end deftypevr
  16138. @deftypevr {@code{inet-listener-configuration} parameter} string address
  16139. The address on which to listen, or empty for all addresses.
  16140. Defaults to @samp{""}.
  16141. @end deftypevr
  16142. @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
  16143. The port on which to listen.
  16144. @end deftypevr
  16145. @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
  16146. Whether to use SSL for this service; @samp{yes}, @samp{no}, or
  16147. @samp{required}.
  16148. Defaults to @samp{#t}.
  16149. @end deftypevr
  16150. @end deftypevr
  16151. @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
  16152. Maximum number of simultaneous client connections per process. Once
  16153. this number of connections is received, the next incoming connection
  16154. will prompt Dovecot to spawn another process. If set to 0,
  16155. @code{default-client-limit} is used instead.
  16156. Defaults to @samp{0}.
  16157. @end deftypevr
  16158. @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
  16159. Number of connections to handle before starting a new process.
  16160. Typically the only useful values are 0 (unlimited) or 1. 1 is more
  16161. secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
  16162. Defaults to @samp{1}.
  16163. @end deftypevr
  16164. @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
  16165. Maximum number of processes that can exist for this service. If set to
  16166. 0, @code{default-process-limit} is used instead.
  16167. Defaults to @samp{0}.
  16168. @end deftypevr
  16169. @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
  16170. Number of processes to always keep waiting for more connections.
  16171. Defaults to @samp{0}.
  16172. @end deftypevr
  16173. @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
  16174. If you set @samp{service-count 0}, you probably need to grow
  16175. this.
  16176. Defaults to @samp{256000000}.
  16177. @end deftypevr
  16178. @end deftypevr
  16179. @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
  16180. Dict configuration, as created by the @code{dict-configuration}
  16181. constructor.
  16182. Available @code{dict-configuration} fields are:
  16183. @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
  16184. A list of key-value pairs that this dict should hold.
  16185. Defaults to @samp{()}.
  16186. @end deftypevr
  16187. @end deftypevr
  16188. @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
  16189. A list of passdb configurations, each one created by the
  16190. @code{passdb-configuration} constructor.
  16191. Available @code{passdb-configuration} fields are:
  16192. @deftypevr {@code{passdb-configuration} parameter} string driver
  16193. The driver that the passdb should use. Valid values include
  16194. @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
  16195. @samp{static}.
  16196. Defaults to @samp{"pam"}.
  16197. @end deftypevr
  16198. @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
  16199. Space separated list of arguments to the passdb driver.
  16200. Defaults to @samp{""}.
  16201. @end deftypevr
  16202. @end deftypevr
  16203. @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
  16204. List of userdb configurations, each one created by the
  16205. @code{userdb-configuration} constructor.
  16206. Available @code{userdb-configuration} fields are:
  16207. @deftypevr {@code{userdb-configuration} parameter} string driver
  16208. The driver that the userdb should use. Valid values include
  16209. @samp{passwd} and @samp{static}.
  16210. Defaults to @samp{"passwd"}.
  16211. @end deftypevr
  16212. @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
  16213. Space separated list of arguments to the userdb driver.
  16214. Defaults to @samp{""}.
  16215. @end deftypevr
  16216. @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
  16217. Override fields from passwd.
  16218. Defaults to @samp{()}.
  16219. @end deftypevr
  16220. @end deftypevr
  16221. @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
  16222. Plug-in configuration, created by the @code{plugin-configuration}
  16223. constructor.
  16224. @end deftypevr
  16225. @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
  16226. List of namespaces. Each item in the list is created by the
  16227. @code{namespace-configuration} constructor.
  16228. Available @code{namespace-configuration} fields are:
  16229. @deftypevr {@code{namespace-configuration} parameter} string name
  16230. Name for this namespace.
  16231. @end deftypevr
  16232. @deftypevr {@code{namespace-configuration} parameter} string type
  16233. Namespace type: @samp{private}, @samp{shared} or @samp{public}.
  16234. Defaults to @samp{"private"}.
  16235. @end deftypevr
  16236. @deftypevr {@code{namespace-configuration} parameter} string separator
  16237. Hierarchy separator to use. You should use the same separator for
  16238. all namespaces or some clients get confused. @samp{/} is usually a good
  16239. one. The default however depends on the underlying mail storage
  16240. format.
  16241. Defaults to @samp{""}.
  16242. @end deftypevr
  16243. @deftypevr {@code{namespace-configuration} parameter} string prefix
  16244. Prefix required to access this namespace. This needs to be
  16245. different for all namespaces. For example @samp{Public/}.
  16246. Defaults to @samp{""}.
  16247. @end deftypevr
  16248. @deftypevr {@code{namespace-configuration} parameter} string location
  16249. Physical location of the mailbox. This is in the same format as
  16250. mail_location, which is also the default for it.
  16251. Defaults to @samp{""}.
  16252. @end deftypevr
  16253. @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
  16254. There can be only one INBOX, and this setting defines which
  16255. namespace has it.
  16256. Defaults to @samp{#f}.
  16257. @end deftypevr
  16258. @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
  16259. If namespace is hidden, it's not advertised to clients via NAMESPACE
  16260. extension. You'll most likely also want to set @samp{list? #f}. This is mostly
  16261. useful when converting from another server with different namespaces
  16262. which you want to deprecate but still keep working. For example you can
  16263. create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
  16264. and @samp{mail/}.
  16265. Defaults to @samp{#f}.
  16266. @end deftypevr
  16267. @deftypevr {@code{namespace-configuration} parameter} boolean list?
  16268. Show the mailboxes under this namespace with the LIST command. This
  16269. makes the namespace visible for clients that do not support the NAMESPACE
  16270. extension. The special @code{children} value lists child mailboxes, but
  16271. hides the namespace prefix.
  16272. Defaults to @samp{#t}.
  16273. @end deftypevr
  16274. @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
  16275. Namespace handles its own subscriptions. If set to @code{#f}, the
  16276. parent namespace handles them. The empty prefix should always have this
  16277. as @code{#t}).
  16278. Defaults to @samp{#t}.
  16279. @end deftypevr
  16280. @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
  16281. List of predefined mailboxes in this namespace.
  16282. Defaults to @samp{()}.
  16283. Available @code{mailbox-configuration} fields are:
  16284. @deftypevr {@code{mailbox-configuration} parameter} string name
  16285. Name for this mailbox.
  16286. @end deftypevr
  16287. @deftypevr {@code{mailbox-configuration} parameter} string auto
  16288. @samp{create} will automatically create this mailbox.
  16289. @samp{subscribe} will both create and subscribe to the mailbox.
  16290. Defaults to @samp{"no"}.
  16291. @end deftypevr
  16292. @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
  16293. List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
  16294. Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
  16295. @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
  16296. Defaults to @samp{()}.
  16297. @end deftypevr
  16298. @end deftypevr
  16299. @end deftypevr
  16300. @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
  16301. Base directory where to store runtime data.
  16302. Defaults to @samp{"/var/run/dovecot/"}.
  16303. @end deftypevr
  16304. @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
  16305. Greeting message for clients.
  16306. Defaults to @samp{"Dovecot ready."}.
  16307. @end deftypevr
  16308. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
  16309. List of trusted network ranges. Connections from these IPs are
  16310. allowed to override their IP addresses and ports (for logging and for
  16311. authentication checks). @samp{disable-plaintext-auth} is also ignored
  16312. for these networks. Typically you would specify your IMAP proxy servers
  16313. here.
  16314. Defaults to @samp{()}.
  16315. @end deftypevr
  16316. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
  16317. List of login access check sockets (e.g.@: tcpwrap).
  16318. Defaults to @samp{()}.
  16319. @end deftypevr
  16320. @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
  16321. Show more verbose process titles (in ps). Currently shows user name
  16322. and IP address. Useful for seeing who is actually using the IMAP
  16323. processes (e.g.@: shared mailboxes or if the same uid is used for multiple
  16324. accounts).
  16325. Defaults to @samp{#f}.
  16326. @end deftypevr
  16327. @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
  16328. Should all processes be killed when Dovecot master process shuts down.
  16329. Setting this to @code{#f} means that Dovecot can be upgraded without
  16330. forcing existing client connections to close (although that could also
  16331. be a problem if the upgrade is e.g.@: due to a security fix).
  16332. Defaults to @samp{#t}.
  16333. @end deftypevr
  16334. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
  16335. If non-zero, run mail commands via this many connections to doveadm
  16336. server, instead of running them directly in the same process.
  16337. Defaults to @samp{0}.
  16338. @end deftypevr
  16339. @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
  16340. UNIX socket or host:port used for connecting to doveadm server.
  16341. Defaults to @samp{"doveadm-server"}.
  16342. @end deftypevr
  16343. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
  16344. List of environment variables that are preserved on Dovecot startup
  16345. and passed down to all of its child processes. You can also give
  16346. key=value pairs to always set specific settings.
  16347. @end deftypevr
  16348. @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
  16349. Disable LOGIN command and all other plaintext authentications unless
  16350. SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
  16351. matches the local IP (i.e.@: you're connecting from the same computer),
  16352. the connection is considered secure and plaintext authentication is
  16353. allowed. See also ssl=required setting.
  16354. Defaults to @samp{#t}.
  16355. @end deftypevr
  16356. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
  16357. Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
  16358. Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
  16359. for caching to be used.
  16360. Defaults to @samp{0}.
  16361. @end deftypevr
  16362. @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
  16363. Time to live for cached data. After TTL expires the cached record
  16364. is no longer used, *except* if the main database lookup returns internal
  16365. failure. We also try to handle password changes automatically: If
  16366. user's previous authentication was successful, but this one wasn't, the
  16367. cache isn't used. For now this works only with plaintext
  16368. authentication.
  16369. Defaults to @samp{"1 hour"}.
  16370. @end deftypevr
  16371. @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
  16372. TTL for negative hits (user not found, password mismatch).
  16373. 0 disables caching them completely.
  16374. Defaults to @samp{"1 hour"}.
  16375. @end deftypevr
  16376. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
  16377. List of realms for SASL authentication mechanisms that need them.
  16378. You can leave it empty if you don't want to support multiple realms.
  16379. Many clients simply use the first one listed here, so keep the default
  16380. realm first.
  16381. Defaults to @samp{()}.
  16382. @end deftypevr
  16383. @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
  16384. Default realm/domain to use if none was specified. This is used for
  16385. both SASL realms and appending @@domain to username in plaintext
  16386. logins.
  16387. Defaults to @samp{""}.
  16388. @end deftypevr
  16389. @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
  16390. List of allowed characters in username. If the user-given username
  16391. contains a character not listed in here, the login automatically fails.
  16392. This is just an extra check to make sure user can't exploit any
  16393. potential quote escaping vulnerabilities with SQL/LDAP databases. If
  16394. you want to allow all characters, set this value to empty.
  16395. Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
  16396. @end deftypevr
  16397. @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
  16398. Username character translations before it's looked up from
  16399. databases. The value contains series of from -> to characters. For
  16400. example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
  16401. translated to @samp{@@}.
  16402. Defaults to @samp{""}.
  16403. @end deftypevr
  16404. @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
  16405. Username formatting before it's looked up from databases. You can
  16406. use the standard variables here, e.g.@: %Lu would lowercase the username,
  16407. %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
  16408. change the @samp{@@} into @samp{-AT-}. This translation is done after
  16409. @samp{auth-username-translation} changes.
  16410. Defaults to @samp{"%Lu"}.
  16411. @end deftypevr
  16412. @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
  16413. If you want to allow master users to log in by specifying the master
  16414. username within the normal username string (i.e.@: not using SASL
  16415. mechanism's support for it), you can specify the separator character
  16416. here. The format is then <username><separator><master username>.
  16417. UW-IMAP uses @samp{*} as the separator, so that could be a good
  16418. choice.
  16419. Defaults to @samp{""}.
  16420. @end deftypevr
  16421. @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
  16422. Username to use for users logging in with ANONYMOUS SASL
  16423. mechanism.
  16424. Defaults to @samp{"anonymous"}.
  16425. @end deftypevr
  16426. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
  16427. Maximum number of dovecot-auth worker processes. They're used to
  16428. execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
  16429. They're automatically created and destroyed as needed.
  16430. Defaults to @samp{30}.
  16431. @end deftypevr
  16432. @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
  16433. Host name to use in GSSAPI principal names. The default is to use
  16434. the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
  16435. allow all keytab entries.
  16436. Defaults to @samp{""}.
  16437. @end deftypevr
  16438. @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
  16439. Kerberos keytab to use for the GSSAPI mechanism. Will use the
  16440. system default (usually @file{/etc/krb5.keytab}) if not specified. You may
  16441. need to change the auth service to run as root to be able to read this
  16442. file.
  16443. Defaults to @samp{""}.
  16444. @end deftypevr
  16445. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
  16446. Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
  16447. and @samp{ntlm-auth} helper.
  16448. <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
  16449. Defaults to @samp{#f}.
  16450. @end deftypevr
  16451. @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
  16452. Path for Samba's @samp{ntlm-auth} helper binary.
  16453. Defaults to @samp{"/usr/bin/ntlm_auth"}.
  16454. @end deftypevr
  16455. @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
  16456. Time to delay before replying to failed authentications.
  16457. Defaults to @samp{"2 secs"}.
  16458. @end deftypevr
  16459. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
  16460. Require a valid SSL client certificate or the authentication
  16461. fails.
  16462. Defaults to @samp{#f}.
  16463. @end deftypevr
  16464. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
  16465. Take the username from client's SSL certificate, using
  16466. @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
  16467. CommonName.
  16468. Defaults to @samp{#f}.
  16469. @end deftypevr
  16470. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
  16471. List of wanted authentication mechanisms. Supported mechanisms are:
  16472. @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
  16473. @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
  16474. @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
  16475. @samp{disable-plaintext-auth} setting.
  16476. @end deftypevr
  16477. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
  16478. List of IPs or hostnames to all director servers, including ourself.
  16479. Ports can be specified as ip:port. The default port is the same as what
  16480. director service's @samp{inet-listener} is using.
  16481. Defaults to @samp{()}.
  16482. @end deftypevr
  16483. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
  16484. List of IPs or hostnames to all backend mail servers. Ranges are
  16485. allowed too, like 10.0.0.10-10.0.0.30.
  16486. Defaults to @samp{()}.
  16487. @end deftypevr
  16488. @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
  16489. How long to redirect users to a specific server after it no longer
  16490. has any connections.
  16491. Defaults to @samp{"15 min"}.
  16492. @end deftypevr
  16493. @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
  16494. How the username is translated before being hashed. Useful values
  16495. include %Ln if user can log in with or without @@domain, %Ld if mailboxes
  16496. are shared within domain.
  16497. Defaults to @samp{"%Lu"}.
  16498. @end deftypevr
  16499. @deftypevr {@code{dovecot-configuration} parameter} string log-path
  16500. Log file to use for error messages. @samp{syslog} logs to syslog,
  16501. @samp{/dev/stderr} logs to stderr.
  16502. Defaults to @samp{"syslog"}.
  16503. @end deftypevr
  16504. @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
  16505. Log file to use for informational messages. Defaults to
  16506. @samp{log-path}.
  16507. Defaults to @samp{""}.
  16508. @end deftypevr
  16509. @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
  16510. Log file to use for debug messages. Defaults to
  16511. @samp{info-log-path}.
  16512. Defaults to @samp{""}.
  16513. @end deftypevr
  16514. @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
  16515. Syslog facility to use if you're logging to syslog. Usually if you
  16516. don't want to use @samp{mail}, you'll use local0..local7. Also other
  16517. standard facilities are supported.
  16518. Defaults to @samp{"mail"}.
  16519. @end deftypevr
  16520. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
  16521. Log unsuccessful authentication attempts and the reasons why they
  16522. failed.
  16523. Defaults to @samp{#f}.
  16524. @end deftypevr
  16525. @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
  16526. In case of password mismatches, log the attempted password. Valid
  16527. values are no, plain and sha1. sha1 can be useful for detecting brute
  16528. force password attempts vs. user simply trying the same password over
  16529. and over again. You can also truncate the value to n chars by appending
  16530. ":n" (e.g.@: sha1:6).
  16531. Defaults to @samp{"no"}.
  16532. @end deftypevr
  16533. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
  16534. Even more verbose logging for debugging purposes. Shows for example
  16535. SQL queries.
  16536. Defaults to @samp{#f}.
  16537. @end deftypevr
  16538. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
  16539. In case of password mismatches, log the passwords and used scheme so
  16540. the problem can be debugged. Enabling this also enables
  16541. @samp{auth-debug}.
  16542. Defaults to @samp{#f}.
  16543. @end deftypevr
  16544. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
  16545. Enable mail process debugging. This can help you figure out why
  16546. Dovecot isn't finding your mails.
  16547. Defaults to @samp{#f}.
  16548. @end deftypevr
  16549. @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
  16550. Show protocol level SSL errors.
  16551. Defaults to @samp{#f}.
  16552. @end deftypevr
  16553. @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
  16554. Prefix for each line written to log file. % codes are in
  16555. strftime(3) format.
  16556. Defaults to @samp{"\"%b %d %H:%M:%S \""}.
  16557. @end deftypevr
  16558. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
  16559. List of elements we want to log. The elements which have a
  16560. non-empty variable value are joined together to form a comma-separated
  16561. string.
  16562. @end deftypevr
  16563. @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
  16564. Login log format. %s contains @samp{login-log-format-elements}
  16565. string, %$ contains the data we want to log.
  16566. Defaults to @samp{"%$: %s"}.
  16567. @end deftypevr
  16568. @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
  16569. Log prefix for mail processes. See doc/wiki/Variables.txt for list
  16570. of possible variables you can use.
  16571. Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
  16572. @end deftypevr
  16573. @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
  16574. Format to use for logging mail deliveries. You can use variables:
  16575. @table @code
  16576. @item %$
  16577. Delivery status message (e.g.@: @samp{saved to INBOX})
  16578. @item %m
  16579. Message-ID
  16580. @item %s
  16581. Subject
  16582. @item %f
  16583. From address
  16584. @item %p
  16585. Physical size
  16586. @item %w
  16587. Virtual size.
  16588. @end table
  16589. Defaults to @samp{"msgid=%m: %$"}.
  16590. @end deftypevr
  16591. @deftypevr {@code{dovecot-configuration} parameter} string mail-location
  16592. Location for users' mailboxes. The default is empty, which means
  16593. that Dovecot tries to find the mailboxes automatically. This won't work
  16594. if the user doesn't yet have any mail, so you should explicitly tell
  16595. Dovecot the full location.
  16596. If you're using mbox, giving a path to the INBOX
  16597. file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
  16598. where the other mailboxes are kept. This is called the @emph{root mail
  16599. directory}, and it must be the first path given in the
  16600. @samp{mail-location} setting.
  16601. There are a few special variables you can use, e.g.:
  16602. @table @samp
  16603. @item %u
  16604. username
  16605. @item %n
  16606. user part in user@@domain, same as %u if there's no domain
  16607. @item %d
  16608. domain part in user@@domain, empty if there's no domain
  16609. @item %h
  16610. home director
  16611. @end table
  16612. See doc/wiki/Variables.txt for full list. Some examples:
  16613. @table @samp
  16614. @item maildir:~/Maildir
  16615. @item mbox:~/mail:INBOX=/var/mail/%u
  16616. @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
  16617. @end table
  16618. Defaults to @samp{""}.
  16619. @end deftypevr
  16620. @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
  16621. System user and group used to access mails. If you use multiple,
  16622. userdb can override these by returning uid or gid fields. You can use
  16623. either numbers or names. <doc/wiki/UserIds.txt>.
  16624. Defaults to @samp{""}.
  16625. @end deftypevr
  16626. @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
  16627. Defaults to @samp{""}.
  16628. @end deftypevr
  16629. @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
  16630. Group to enable temporarily for privileged operations. Currently
  16631. this is used only with INBOX when either its initial creation or
  16632. dotlocking fails. Typically this is set to @samp{"mail"} to give access to
  16633. @file{/var/mail}.
  16634. Defaults to @samp{""}.
  16635. @end deftypevr
  16636. @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
  16637. Grant access to these supplementary groups for mail processes.
  16638. Typically these are used to set up access to shared mailboxes. Note
  16639. that it may be dangerous to set these if users can create symlinks
  16640. (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
  16641. could allow a user to delete others' mailboxes, or @code{ln -s
  16642. /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
  16643. @samp{""}.
  16644. @end deftypevr
  16645. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
  16646. Allow full file system access to clients. There's no access checks
  16647. other than what the operating system does for the active UID/GID@. It
  16648. works with both maildir and mboxes, allowing you to prefix mailboxes
  16649. names with e.g.@: @file{/path/} or @file{~user/}.
  16650. Defaults to @samp{#f}.
  16651. @end deftypevr
  16652. @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
  16653. Don't use @code{mmap()} at all. This is required if you store indexes to
  16654. shared file systems (NFS or clustered file system).
  16655. Defaults to @samp{#f}.
  16656. @end deftypevr
  16657. @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
  16658. Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
  16659. supports @samp{O_EXCL} since version 3, so this should be safe to use
  16660. nowadays by default.
  16661. Defaults to @samp{#t}.
  16662. @end deftypevr
  16663. @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
  16664. When to use fsync() or fdatasync() calls:
  16665. @table @code
  16666. @item optimized
  16667. Whenever necessary to avoid losing important data
  16668. @item always
  16669. Useful with e.g.@: NFS when @code{write()}s are delayed
  16670. @item never
  16671. Never use it (best performance, but crashes can lose data).
  16672. @end table
  16673. Defaults to @samp{"optimized"}.
  16674. @end deftypevr
  16675. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
  16676. Mail storage exists in NFS@. Set this to yes to make Dovecot flush
  16677. NFS caches whenever needed. If you're using only a single mail server
  16678. this isn't needed.
  16679. Defaults to @samp{#f}.
  16680. @end deftypevr
  16681. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
  16682. Mail index files also exist in NFS@. Setting this to yes requires
  16683. @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
  16684. Defaults to @samp{#f}.
  16685. @end deftypevr
  16686. @deftypevr {@code{dovecot-configuration} parameter} string lock-method
  16687. Locking method for index files. Alternatives are fcntl, flock and
  16688. dotlock. Dotlocking uses some tricks which may create more disk I/O
  16689. than other locking methods. NFS users: flock doesn't work, remember to
  16690. change @samp{mmap-disable}.
  16691. Defaults to @samp{"fcntl"}.
  16692. @end deftypevr
  16693. @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
  16694. Directory in which LDA/LMTP temporarily stores incoming mails >128
  16695. kB.
  16696. Defaults to @samp{"/tmp"}.
  16697. @end deftypevr
  16698. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
  16699. Valid UID range for users. This is mostly to make sure that users can't
  16700. log in as daemons or other system users. Note that denying root logins is
  16701. hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
  16702. is set to 0.
  16703. Defaults to @samp{500}.
  16704. @end deftypevr
  16705. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
  16706. Defaults to @samp{0}.
  16707. @end deftypevr
  16708. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
  16709. Valid GID range for users. Users having non-valid GID as primary group ID
  16710. aren't allowed to log in. If user belongs to supplementary groups with
  16711. non-valid GIDs, those groups are not set.
  16712. Defaults to @samp{1}.
  16713. @end deftypevr
  16714. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
  16715. Defaults to @samp{0}.
  16716. @end deftypevr
  16717. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
  16718. Maximum allowed length for mail keyword name. It's only forced when
  16719. trying to create new keywords.
  16720. Defaults to @samp{50}.
  16721. @end deftypevr
  16722. @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
  16723. List of directories under which chrooting is allowed for mail
  16724. processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
  16725. too). This setting doesn't affect @samp{login-chroot}
  16726. @samp{mail-chroot} or auth chroot settings. If this setting is empty,
  16727. @samp{/./} in home dirs are ignored. WARNING: Never add directories here
  16728. which local users can modify, that may lead to root exploit. Usually
  16729. this should be done only if you don't allow shell access for users.
  16730. <doc/wiki/Chrooting.txt>.
  16731. Defaults to @samp{()}.
  16732. @end deftypevr
  16733. @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
  16734. Default chroot directory for mail processes. This can be overridden
  16735. for specific users in user database by giving @samp{/./} in user's home
  16736. directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
  16737. there is no real need to do chrooting, Dovecot doesn't allow users to
  16738. access files outside their mail directory anyway. If your home
  16739. directories are prefixed with the chroot directory, append @samp{/.} to
  16740. @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
  16741. Defaults to @samp{""}.
  16742. @end deftypevr
  16743. @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
  16744. UNIX socket path to master authentication server to find users.
  16745. This is used by imap (for shared users) and lda.
  16746. Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
  16747. @end deftypevr
  16748. @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
  16749. Directory where to look up mail plugins.
  16750. Defaults to @samp{"/usr/lib/dovecot"}.
  16751. @end deftypevr
  16752. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
  16753. List of plugins to load for all services. Plugins specific to IMAP,
  16754. LDA, etc.@: are added to this list in their own .conf files.
  16755. Defaults to @samp{()}.
  16756. @end deftypevr
  16757. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
  16758. The minimum number of mails in a mailbox before updates are done to
  16759. cache file. This allows optimizing Dovecot's behavior to do less disk
  16760. writes at the cost of more disk reads.
  16761. Defaults to @samp{0}.
  16762. @end deftypevr
  16763. @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
  16764. When IDLE command is running, mailbox is checked once in a while to
  16765. see if there are any new mails or other changes. This setting defines
  16766. the minimum time to wait between those checks. Dovecot can also use
  16767. dnotify, inotify and kqueue to find out immediately when changes
  16768. occur.
  16769. Defaults to @samp{"30 secs"}.
  16770. @end deftypevr
  16771. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
  16772. Save mails with CR+LF instead of plain LF@. This makes sending those
  16773. mails take less CPU, especially with sendfile() syscall with Linux and
  16774. FreeBSD@. But it also creates a bit more disk I/O which may just make it
  16775. slower. Also note that if other software reads the mboxes/maildirs,
  16776. they may handle the extra CRs wrong and cause problems.
  16777. Defaults to @samp{#f}.
  16778. @end deftypevr
  16779. @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
  16780. By default LIST command returns all entries in maildir beginning
  16781. with a dot. Enabling this option makes Dovecot return only entries
  16782. which are directories. This is done by stat()ing each entry, so it
  16783. causes more disk I/O.
  16784. (For systems setting struct @samp{dirent->d_type} this check is free
  16785. and it's done always regardless of this setting).
  16786. Defaults to @samp{#f}.
  16787. @end deftypevr
  16788. @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
  16789. When copying a message, do it with hard links whenever possible.
  16790. This makes the performance much better, and it's unlikely to have any
  16791. side effects.
  16792. Defaults to @samp{#t}.
  16793. @end deftypevr
  16794. @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
  16795. Assume Dovecot is the only MUA accessing Maildir: Scan cur/
  16796. directory only when its mtime changes unexpectedly or when we can't find
  16797. the mail otherwise.
  16798. Defaults to @samp{#f}.
  16799. @end deftypevr
  16800. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
  16801. Which locking methods to use for locking mbox. There are four
  16802. available:
  16803. @table @code
  16804. @item dotlock
  16805. Create <mailbox>.lock file. This is the oldest and most NFS-safe
  16806. solution. If you want to use /var/mail/ like directory, the users will
  16807. need write access to that directory.
  16808. @item dotlock-try
  16809. Same as dotlock, but if it fails because of permissions or because there
  16810. isn't enough disk space, just skip it.
  16811. @item fcntl
  16812. Use this if possible. Works with NFS too if lockd is used.
  16813. @item flock
  16814. May not exist in all systems. Doesn't work with NFS.
  16815. @item lockf
  16816. May not exist in all systems. Doesn't work with NFS.
  16817. @end table
  16818. You can use multiple locking methods; if you do the order they're declared
  16819. in is important to avoid deadlocks if other MTAs/MUAs are using multiple
  16820. locking methods as well. Some operating systems don't allow using some of
  16821. them simultaneously.
  16822. @end deftypevr
  16823. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
  16824. @end deftypevr
  16825. @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
  16826. Maximum time to wait for lock (all of them) before aborting.
  16827. Defaults to @samp{"5 mins"}.
  16828. @end deftypevr
  16829. @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
  16830. If dotlock exists but the mailbox isn't modified in any way,
  16831. override the lock file after this much time.
  16832. Defaults to @samp{"2 mins"}.
  16833. @end deftypevr
  16834. @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
  16835. When mbox changes unexpectedly we have to fully read it to find out
  16836. what changed. If the mbox is large this can take a long time. Since
  16837. the change is usually just a newly appended mail, it'd be faster to
  16838. simply read the new mails. If this setting is enabled, Dovecot does
  16839. this but still safely fallbacks to re-reading the whole mbox file
  16840. whenever something in mbox isn't how it's expected to be. The only real
  16841. downside to this setting is that if some other MUA changes message
  16842. flags, Dovecot doesn't notice it immediately. Note that a full sync is
  16843. done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
  16844. Defaults to @samp{#t}.
  16845. @end deftypevr
  16846. @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
  16847. Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
  16848. EXAMINE, EXPUNGE or CHECK commands. If this is set,
  16849. @samp{mbox-dirty-syncs} is ignored.
  16850. Defaults to @samp{#f}.
  16851. @end deftypevr
  16852. @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
  16853. Delay writing mbox headers until doing a full write sync (EXPUNGE
  16854. and CHECK commands and when closing the mailbox). This is especially
  16855. useful for POP3 where clients often delete all mails. The downside is
  16856. that our changes aren't immediately visible to other MUAs.
  16857. Defaults to @samp{#t}.
  16858. @end deftypevr
  16859. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
  16860. If mbox size is smaller than this (e.g.@: 100k), don't write index
  16861. files. If an index file already exists it's still read, just not
  16862. updated.
  16863. Defaults to @samp{0}.
  16864. @end deftypevr
  16865. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
  16866. Maximum dbox file size until it's rotated.
  16867. Defaults to @samp{10000000}.
  16868. @end deftypevr
  16869. @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
  16870. Maximum dbox file age until it's rotated. Typically in days. Day
  16871. begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
  16872. disabled.
  16873. Defaults to @samp{"1d"}.
  16874. @end deftypevr
  16875. @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
  16876. When creating new mdbox files, immediately preallocate their size to
  16877. @samp{mdbox-rotate-size}. This setting currently works only in Linux
  16878. with some file systems (ext4, xfs).
  16879. Defaults to @samp{#f}.
  16880. @end deftypevr
  16881. @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
  16882. sdbox and mdbox support saving mail attachments to external files,
  16883. which also allows single instance storage for them. Other backends
  16884. don't support this for now.
  16885. WARNING: This feature hasn't been tested much yet. Use at your own risk.
  16886. Directory root where to store mail attachments. Disabled, if empty.
  16887. Defaults to @samp{""}.
  16888. @end deftypevr
  16889. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
  16890. Attachments smaller than this aren't saved externally. It's also
  16891. possible to write a plugin to disable saving specific attachments
  16892. externally.
  16893. Defaults to @samp{128000}.
  16894. @end deftypevr
  16895. @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
  16896. File system backend to use for saving attachments:
  16897. @table @code
  16898. @item posix
  16899. No SiS done by Dovecot (but this might help FS's own deduplication)
  16900. @item sis posix
  16901. SiS with immediate byte-by-byte comparison during saving
  16902. @item sis-queue posix
  16903. SiS with delayed comparison and deduplication.
  16904. @end table
  16905. Defaults to @samp{"sis posix"}.
  16906. @end deftypevr
  16907. @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
  16908. Hash format to use in attachment filenames. You can add any text and
  16909. variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
  16910. @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
  16911. truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
  16912. Defaults to @samp{"%@{sha1@}"}.
  16913. @end deftypevr
  16914. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
  16915. Defaults to @samp{100}.
  16916. @end deftypevr
  16917. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
  16918. Defaults to @samp{1000}.
  16919. @end deftypevr
  16920. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
  16921. Default VSZ (virtual memory size) limit for service processes.
  16922. This is mainly intended to catch and kill processes that leak memory
  16923. before they eat up everything.
  16924. Defaults to @samp{256000000}.
  16925. @end deftypevr
  16926. @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
  16927. Login user is internally used by login processes. This is the most
  16928. untrusted user in Dovecot system. It shouldn't have access to anything
  16929. at all.
  16930. Defaults to @samp{"dovenull"}.
  16931. @end deftypevr
  16932. @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
  16933. Internal user is used by unprivileged processes. It should be
  16934. separate from login user, so that login processes can't disturb other
  16935. processes.
  16936. Defaults to @samp{"dovecot"}.
  16937. @end deftypevr
  16938. @deftypevr {@code{dovecot-configuration} parameter} string ssl?
  16939. SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
  16940. Defaults to @samp{"required"}.
  16941. @end deftypevr
  16942. @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
  16943. PEM encoded X.509 SSL/TLS certificate (public key).
  16944. Defaults to @samp{"</etc/dovecot/default.pem"}.
  16945. @end deftypevr
  16946. @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
  16947. PEM encoded SSL/TLS private key. The key is opened before
  16948. dropping root privileges, so keep the key file unreadable by anyone but
  16949. root.
  16950. Defaults to @samp{"</etc/dovecot/private/default.pem"}.
  16951. @end deftypevr
  16952. @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
  16953. If key file is password protected, give the password here.
  16954. Alternatively give it when starting dovecot with -p parameter. Since
  16955. this file is often world-readable, you may want to place this setting
  16956. instead to a different.
  16957. Defaults to @samp{""}.
  16958. @end deftypevr
  16959. @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
  16960. PEM encoded trusted certificate authority. Set this only if you
  16961. intend to use @samp{ssl-verify-client-cert? #t}. The file should
  16962. contain the CA certificate(s) followed by the matching
  16963. CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
  16964. Defaults to @samp{""}.
  16965. @end deftypevr
  16966. @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
  16967. Require that CRL check succeeds for client certificates.
  16968. Defaults to @samp{#t}.
  16969. @end deftypevr
  16970. @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
  16971. Request client to send a certificate. If you also want to require
  16972. it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
  16973. Defaults to @samp{#f}.
  16974. @end deftypevr
  16975. @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
  16976. Which field from certificate to use for username. commonName and
  16977. x500UniqueIdentifier are the usual choices. You'll also need to set
  16978. @samp{auth-ssl-username-from-cert? #t}.
  16979. Defaults to @samp{"commonName"}.
  16980. @end deftypevr
  16981. @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
  16982. Minimum SSL protocol version to accept.
  16983. Defaults to @samp{"TLSv1"}.
  16984. @end deftypevr
  16985. @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
  16986. SSL ciphers to use.
  16987. Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
  16988. @end deftypevr
  16989. @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
  16990. SSL crypto device to use, for valid values run "openssl engine".
  16991. Defaults to @samp{""}.
  16992. @end deftypevr
  16993. @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
  16994. Address to use when sending rejection mails.
  16995. %d expands to recipient domain.
  16996. Defaults to @samp{"postmaster@@%d"}.
  16997. @end deftypevr
  16998. @deftypevr {@code{dovecot-configuration} parameter} string hostname
  16999. Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
  17000. and in LMTP replies. Default is the system's real hostname@@domain.
  17001. Defaults to @samp{""}.
  17002. @end deftypevr
  17003. @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
  17004. If user is over quota, return with temporary failure instead of
  17005. bouncing the mail.
  17006. Defaults to @samp{#f}.
  17007. @end deftypevr
  17008. @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
  17009. Binary to use for sending mails.
  17010. Defaults to @samp{"/usr/sbin/sendmail"}.
  17011. @end deftypevr
  17012. @deftypevr {@code{dovecot-configuration} parameter} string submission-host
  17013. If non-empty, send mails via this SMTP host[:port] instead of
  17014. sendmail.
  17015. Defaults to @samp{""}.
  17016. @end deftypevr
  17017. @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
  17018. Subject: header to use for rejection mails. You can use the same
  17019. variables as for @samp{rejection-reason} below.
  17020. Defaults to @samp{"Rejected: %s"}.
  17021. @end deftypevr
  17022. @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
  17023. Human readable error message for rejection mails. You can use
  17024. variables:
  17025. @table @code
  17026. @item %n
  17027. CRLF
  17028. @item %r
  17029. reason
  17030. @item %s
  17031. original subject
  17032. @item %t
  17033. recipient
  17034. @end table
  17035. Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
  17036. @end deftypevr
  17037. @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
  17038. Delimiter character between local-part and detail in email
  17039. address.
  17040. Defaults to @samp{"+"}.
  17041. @end deftypevr
  17042. @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
  17043. Header where the original recipient address (SMTP's RCPT TO:
  17044. address) is taken from if not available elsewhere. With dovecot-lda -a
  17045. parameter overrides this. A commonly used header for this is
  17046. X-Original-To.
  17047. Defaults to @samp{""}.
  17048. @end deftypevr
  17049. @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
  17050. Should saving a mail to a nonexistent mailbox automatically create
  17051. it?.
  17052. Defaults to @samp{#f}.
  17053. @end deftypevr
  17054. @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
  17055. Should automatically created mailboxes be also automatically
  17056. subscribed?.
  17057. Defaults to @samp{#f}.
  17058. @end deftypevr
  17059. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
  17060. Maximum IMAP command line length. Some clients generate very long
  17061. command lines with huge mailboxes, so you may need to raise this if you
  17062. get "Too long argument" or "IMAP command line too large" errors
  17063. often.
  17064. Defaults to @samp{64000}.
  17065. @end deftypevr
  17066. @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
  17067. IMAP logout format string:
  17068. @table @code
  17069. @item %i
  17070. total number of bytes read from client
  17071. @item %o
  17072. total number of bytes sent to client.
  17073. @end table
  17074. See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
  17075. Defaults to @samp{"in=%i out=%o deleted=%@{deleted@} expunged=%@{expunged@} trashed=%@{trashed@} hdr_count=%@{fetch_hdr_count@} hdr_bytes=%@{fetch_hdr_bytes@} body_count=%@{fetch_body_count@} body_bytes=%@{fetch_body_bytes@}"}.
  17076. @end deftypevr
  17077. @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
  17078. Override the IMAP CAPABILITY response. If the value begins with '+',
  17079. add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
  17080. Defaults to @samp{""}.
  17081. @end deftypevr
  17082. @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
  17083. How long to wait between "OK Still here" notifications when client
  17084. is IDLEing.
  17085. Defaults to @samp{"2 mins"}.
  17086. @end deftypevr
  17087. @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
  17088. ID field names and values to send to clients. Using * as the value
  17089. makes Dovecot use the default value. The following fields have default
  17090. values currently: name, version, os, os-version, support-url,
  17091. support-email.
  17092. Defaults to @samp{""}.
  17093. @end deftypevr
  17094. @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
  17095. ID fields sent by client to log. * means everything.
  17096. Defaults to @samp{""}.
  17097. @end deftypevr
  17098. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
  17099. Workarounds for various client bugs:
  17100. @table @code
  17101. @item delay-newmail
  17102. Send EXISTS/RECENT new mail notifications only when replying to NOOP and
  17103. CHECK commands. Some clients ignore them otherwise, for example OSX
  17104. Mail (<v2.1). Outlook Express breaks more badly though, without this it
  17105. may show user "Message no longer in server" errors. Note that OE6
  17106. still breaks even with this workaround if synchronization is set to
  17107. "Headers Only".
  17108. @item tb-extra-mailbox-sep
  17109. Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
  17110. adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
  17111. ignore the extra @samp{/} instead of treating it as invalid mailbox name.
  17112. @item tb-lsub-flags
  17113. Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
  17114. This makes Thunderbird realize they aren't selectable and show them
  17115. greyed out, instead of only later giving "not selectable" popup error.
  17116. @end table
  17117. Defaults to @samp{()}.
  17118. @end deftypevr
  17119. @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
  17120. Host allowed in URLAUTH URLs sent by client. "*" allows all.
  17121. Defaults to @samp{""}.
  17122. @end deftypevr
  17123. Whew! Lots of configuration options. The nice thing about it though is
  17124. that Guix has a complete interface to Dovecot's configuration
  17125. language. This allows not only a nice way to declare configurations,
  17126. but also offers reflective capabilities as well: users can write code to
  17127. inspect and transform configurations from within Scheme.
  17128. However, it could be that you just want to get a @code{dovecot.conf} up
  17129. and running. In that case, you can pass an
  17130. @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
  17131. @code{dovecot-service}. As its name indicates, an opaque configuration
  17132. does not have easy reflective capabilities.
  17133. Available @code{opaque-dovecot-configuration} fields are:
  17134. @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
  17135. The dovecot package.
  17136. @end deftypevr
  17137. @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
  17138. The contents of the @code{dovecot.conf}, as a string.
  17139. @end deftypevr
  17140. For example, if your @code{dovecot.conf} is just the empty string, you
  17141. could instantiate a dovecot service like this:
  17142. @lisp
  17143. (dovecot-service #:config
  17144. (opaque-dovecot-configuration
  17145. (string "")))
  17146. @end lisp
  17147. @subsubheading OpenSMTPD Service
  17148. @deffn {Scheme Variable} opensmtpd-service-type
  17149. This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
  17150. service, whose value should be an @code{opensmtpd-configuration} object
  17151. as in this example:
  17152. @lisp
  17153. (service opensmtpd-service-type
  17154. (opensmtpd-configuration
  17155. (config-file (local-file "./my-smtpd.conf"))))
  17156. @end lisp
  17157. @end deffn
  17158. @deftp {Data Type} opensmtpd-configuration
  17159. Data type representing the configuration of opensmtpd.
  17160. @table @asis
  17161. @item @code{package} (default: @var{opensmtpd})
  17162. Package object of the OpenSMTPD SMTP server.
  17163. @item @code{config-file} (default: @code{%default-opensmtpd-file})
  17164. File-like object of the OpenSMTPD configuration file to use. By default
  17165. it listens on the loopback network interface, and allows for mail from
  17166. users and daemons on the local machine, as well as permitting email to
  17167. remote servers. Run @command{man smtpd.conf} for more information.
  17168. @end table
  17169. @end deftp
  17170. @subsubheading Exim Service
  17171. @cindex mail transfer agent (MTA)
  17172. @cindex MTA (mail transfer agent)
  17173. @cindex SMTP
  17174. @deffn {Scheme Variable} exim-service-type
  17175. This is the type of the @uref{https://exim.org, Exim} mail transfer
  17176. agent (MTA), whose value should be an @code{exim-configuration} object
  17177. as in this example:
  17178. @lisp
  17179. (service exim-service-type
  17180. (exim-configuration
  17181. (config-file (local-file "./my-exim.conf"))))
  17182. @end lisp
  17183. @end deffn
  17184. In order to use an @code{exim-service-type} service you must also have a
  17185. @code{mail-aliases-service-type} service present in your
  17186. @code{operating-system} (even if it has no aliases).
  17187. @deftp {Data Type} exim-configuration
  17188. Data type representing the configuration of exim.
  17189. @table @asis
  17190. @item @code{package} (default: @var{exim})
  17191. Package object of the Exim server.
  17192. @item @code{config-file} (default: @code{#f})
  17193. File-like object of the Exim configuration file to use. If its value is
  17194. @code{#f} then use the default configuration file from the package
  17195. provided in @code{package}. The resulting configuration file is loaded
  17196. after setting the @code{exim_user} and @code{exim_group} configuration
  17197. variables.
  17198. @end table
  17199. @end deftp
  17200. @subsubheading Getmail service
  17201. @cindex IMAP
  17202. @cindex POP
  17203. @deffn {Scheme Variable} getmail-service-type
  17204. This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
  17205. mail retriever, whose value should be an @code{getmail-configuration}.
  17206. @end deffn
  17207. Available @code{getmail-configuration} fields are:
  17208. @deftypevr {@code{getmail-configuration} parameter} symbol name
  17209. A symbol to identify the getmail service.
  17210. Defaults to @samp{"unset"}.
  17211. @end deftypevr
  17212. @deftypevr {@code{getmail-configuration} parameter} package package
  17213. The getmail package to use.
  17214. @end deftypevr
  17215. @deftypevr {@code{getmail-configuration} parameter} string user
  17216. The user to run getmail as.
  17217. Defaults to @samp{"getmail"}.
  17218. @end deftypevr
  17219. @deftypevr {@code{getmail-configuration} parameter} string group
  17220. The group to run getmail as.
  17221. Defaults to @samp{"getmail"}.
  17222. @end deftypevr
  17223. @deftypevr {@code{getmail-configuration} parameter} string directory
  17224. The getmail directory to use.
  17225. Defaults to @samp{"/var/lib/getmail/default"}.
  17226. @end deftypevr
  17227. @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
  17228. The getmail configuration file to use.
  17229. Available @code{getmail-configuration-file} fields are:
  17230. @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
  17231. What mail account to retrieve mail from, and how to access that account.
  17232. Available @code{getmail-retriever-configuration} fields are:
  17233. @deftypevr {@code{getmail-retriever-configuration} parameter} string type
  17234. The type of mail retriever to use. Valid values include @samp{passwd}
  17235. and @samp{static}.
  17236. Defaults to @samp{"SimpleIMAPSSLRetriever"}.
  17237. @end deftypevr
  17238. @deftypevr {@code{getmail-retriever-configuration} parameter} string server
  17239. Username to login to the mail server with.
  17240. Defaults to @samp{unset}.
  17241. @end deftypevr
  17242. @deftypevr {@code{getmail-retriever-configuration} parameter} string username
  17243. Username to login to the mail server with.
  17244. Defaults to @samp{unset}.
  17245. @end deftypevr
  17246. @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
  17247. Port number to connect to.
  17248. Defaults to @samp{#f}.
  17249. @end deftypevr
  17250. @deftypevr {@code{getmail-retriever-configuration} parameter} string password
  17251. Override fields from passwd.
  17252. Defaults to @samp{""}.
  17253. @end deftypevr
  17254. @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
  17255. Override fields from passwd.
  17256. Defaults to @samp{()}.
  17257. @end deftypevr
  17258. @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
  17259. PEM-formatted key file to use for the TLS negotiation.
  17260. Defaults to @samp{""}.
  17261. @end deftypevr
  17262. @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
  17263. PEM-formatted certificate file to use for the TLS negotiation.
  17264. Defaults to @samp{""}.
  17265. @end deftypevr
  17266. @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
  17267. CA certificates to use.
  17268. Defaults to @samp{""}.
  17269. @end deftypevr
  17270. @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
  17271. Extra retriever parameters.
  17272. Defaults to @samp{()}.
  17273. @end deftypevr
  17274. @end deftypevr
  17275. @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
  17276. What to do with retrieved messages.
  17277. Available @code{getmail-destination-configuration} fields are:
  17278. @deftypevr {@code{getmail-destination-configuration} parameter} string type
  17279. The type of mail destination. Valid values include @samp{Maildir},
  17280. @samp{Mboxrd} and @samp{MDA_external}.
  17281. Defaults to @samp{unset}.
  17282. @end deftypevr
  17283. @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
  17284. The path option for the mail destination. The behaviour depends on the
  17285. chosen type.
  17286. Defaults to @samp{""}.
  17287. @end deftypevr
  17288. @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
  17289. Extra destination parameters
  17290. Defaults to @samp{()}.
  17291. @end deftypevr
  17292. @end deftypevr
  17293. @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
  17294. Configure getmail.
  17295. Available @code{getmail-options-configuration} fields are:
  17296. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
  17297. If set to @samp{0}, getmail will only print warnings and errors. A
  17298. value of @samp{1} means that messages will be printed about retrieving
  17299. and deleting messages. If set to @samp{2}, getmail will print messages
  17300. about each of it's actions.
  17301. Defaults to @samp{1}.
  17302. @end deftypevr
  17303. @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
  17304. If true, getmail will retrieve all available messages. Otherwise it
  17305. will only retrieve messages it hasn't seen previously.
  17306. Defaults to @samp{#t}.
  17307. @end deftypevr
  17308. @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
  17309. If set to true, messages will be deleted from the server after
  17310. retrieving and successfully delivering them. Otherwise, messages will
  17311. be left on the server.
  17312. Defaults to @samp{#f}.
  17313. @end deftypevr
  17314. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
  17315. Getmail will delete messages this number of days after seeing them, if
  17316. they have been delivered. This means messages will be left on the
  17317. server this number of days after delivering them. A value of @samp{0}
  17318. disabled this feature.
  17319. Defaults to @samp{0}.
  17320. @end deftypevr
  17321. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
  17322. Delete messages larger than this of bytes after retrieving them, even if
  17323. the delete and delete-after options are disabled. A value of @samp{0}
  17324. disables this feature.
  17325. Defaults to @samp{0}.
  17326. @end deftypevr
  17327. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
  17328. Retrieve messages totalling up to this number of bytes before closing
  17329. the session with the server. A value of @samp{0} disables this feature.
  17330. Defaults to @samp{0}.
  17331. @end deftypevr
  17332. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
  17333. Don't retrieve messages larger than this number of bytes. A value of
  17334. @samp{0} disables this feature.
  17335. Defaults to @samp{0}.
  17336. @end deftypevr
  17337. @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
  17338. If true, getmail will add a Delivered-To header to messages.
  17339. Defaults to @samp{#t}.
  17340. @end deftypevr
  17341. @deftypevr {@code{getmail-options-configuration} parameter} boolean received
  17342. If set, getmail adds a Received header to the messages.
  17343. Defaults to @samp{#t}.
  17344. @end deftypevr
  17345. @deftypevr {@code{getmail-options-configuration} parameter} string message-log
  17346. Getmail will record a log of its actions to the named file. A value of
  17347. @samp{""} disables this feature.
  17348. Defaults to @samp{""}.
  17349. @end deftypevr
  17350. @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
  17351. If true, getmail will record a log of its actions using the system
  17352. logger.
  17353. Defaults to @samp{#f}.
  17354. @end deftypevr
  17355. @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
  17356. If true, getmail will log information about messages not retrieved and
  17357. the reason for not retrieving them, as well as starting and ending
  17358. information lines.
  17359. Defaults to @samp{#f}.
  17360. @end deftypevr
  17361. @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
  17362. Extra options to include.
  17363. Defaults to @samp{()}.
  17364. @end deftypevr
  17365. @end deftypevr
  17366. @end deftypevr
  17367. @deftypevr {@code{getmail-configuration} parameter} list idle
  17368. A list of mailboxes that getmail should wait on the server for new mail
  17369. notifications. This depends on the server supporting the IDLE
  17370. extension.
  17371. Defaults to @samp{()}.
  17372. @end deftypevr
  17373. @deftypevr {@code{getmail-configuration} parameter} list environment-variables
  17374. Environment variables to set for getmail.
  17375. Defaults to @samp{()}.
  17376. @end deftypevr
  17377. @subsubheading Mail Aliases Service
  17378. @cindex email aliases
  17379. @cindex aliases, for email addresses
  17380. @deffn {Scheme Variable} mail-aliases-service-type
  17381. This is the type of the service which provides @code{/etc/aliases},
  17382. specifying how to deliver mail to users on this system.
  17383. @lisp
  17384. (service mail-aliases-service-type
  17385. '(("postmaster" "bob")
  17386. ("bob" "bob@@example.com" "bob@@example2.com")))
  17387. @end lisp
  17388. @end deffn
  17389. The configuration for a @code{mail-aliases-service-type} service is an
  17390. association list denoting how to deliver mail that comes to this
  17391. system. Each entry is of the form @code{(alias addresses ...)}, with
  17392. @code{alias} specifying the local alias and @code{addresses} specifying
  17393. where to deliver this user's mail.
  17394. The aliases aren't required to exist as users on the local system. In
  17395. the above example, there doesn't need to be a @code{postmaster} entry in
  17396. the @code{operating-system}'s @code{user-accounts} in order to deliver
  17397. the @code{postmaster} mail to @code{bob} (which subsequently would
  17398. deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
  17399. @subsubheading GNU Mailutils IMAP4 Daemon
  17400. @cindex GNU Mailutils IMAP4 Daemon
  17401. @deffn {Scheme Variable} imap4d-service-type
  17402. This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
  17403. mailutils, GNU Mailutils Manual}), whose value should be an
  17404. @code{imap4d-configuration} object as in this example:
  17405. @lisp
  17406. (service imap4d-service-type
  17407. (imap4d-configuration
  17408. (config-file (local-file "imap4d.conf"))))
  17409. @end lisp
  17410. @end deffn
  17411. @deftp {Data Type} imap4d-configuration
  17412. Data type representing the configuration of @command{imap4d}.
  17413. @table @asis
  17414. @item @code{package} (default: @code{mailutils})
  17415. The package that provides @command{imap4d}.
  17416. @item @code{config-file} (default: @code{%default-imap4d-config-file})
  17417. File-like object of the configuration file to use, by default it will listen
  17418. on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
  17419. Mailutils Manual}, for details.
  17420. @end table
  17421. @end deftp
  17422. @subsubheading Radicale Service
  17423. @cindex CalDAV
  17424. @cindex CardDAV
  17425. @deffn {Scheme Variable} radicale-service-type
  17426. This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
  17427. server whose value should be a @code{radicale-configuration}.
  17428. @end deffn
  17429. @deftp {Data Type} radicale-configuration
  17430. Data type representing the configuration of @command{radicale}.
  17431. @table @asis
  17432. @item @code{package} (default: @code{radicale})
  17433. The package that provides @command{radicale}.
  17434. @item @code{config-file} (default: @code{%default-radicale-config-file})
  17435. File-like object of the configuration file to use, by default it will listen
  17436. on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
  17437. @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
  17438. @end table
  17439. @end deftp
  17440. @node Messaging Services
  17441. @subsection Messaging Services
  17442. @cindex messaging
  17443. @cindex jabber
  17444. @cindex XMPP
  17445. The @code{(gnu services messaging)} module provides Guix service
  17446. definitions for messaging services. Currently it provides the following
  17447. services:
  17448. @subsubheading Prosody Service
  17449. @deffn {Scheme Variable} prosody-service-type
  17450. This is the type for the @uref{https://prosody.im, Prosody XMPP
  17451. communication server}. Its value must be a @code{prosody-configuration}
  17452. record as in this example:
  17453. @lisp
  17454. (service prosody-service-type
  17455. (prosody-configuration
  17456. (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
  17457. (int-components
  17458. (list
  17459. (int-component-configuration
  17460. (hostname "conference.example.net")
  17461. (plugin "muc")
  17462. (mod-muc (mod-muc-configuration)))))
  17463. (virtualhosts
  17464. (list
  17465. (virtualhost-configuration
  17466. (domain "example.net"))))))
  17467. @end lisp
  17468. See below for details about @code{prosody-configuration}.
  17469. @end deffn
  17470. By default, Prosody does not need much configuration. Only one
  17471. @code{virtualhosts} field is needed: it specifies the domain you wish
  17472. Prosody to serve.
  17473. You can perform various sanity checks on the generated configuration
  17474. with the @code{prosodyctl check} command.
  17475. Prosodyctl will also help you to import certificates from the
  17476. @code{letsencrypt} directory so that the @code{prosody} user can access
  17477. them. See @url{https://prosody.im/doc/letsencrypt}.
  17478. @example
  17479. prosodyctl --root cert import /etc/letsencrypt/live
  17480. @end example
  17481. The available configuration parameters follow. Each parameter
  17482. definition is preceded by its type; for example, @samp{string-list foo}
  17483. indicates that the @code{foo} parameter should be specified as a list of
  17484. strings. Types starting with @code{maybe-} denote parameters that won't
  17485. show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
  17486. There is also a way to specify the configuration as a string, if you
  17487. have an old @code{prosody.cfg.lua} file that you want to port over from
  17488. some other system; see the end for more details.
  17489. The @code{file-object} type designates either a file-like object
  17490. (@pxref{G-Expressions, file-like objects}) or a file name.
  17491. @c The following documentation was initially generated by
  17492. @c (generate-documentation) in (gnu services messaging). Manually maintained
  17493. @c documentation is better, so we shouldn't hesitate to edit below as
  17494. @c needed. However if the change you want to make to this documentation
  17495. @c can be done in an automated way, it's probably easier to change
  17496. @c (generate-documentation) than to make it below and have to deal with
  17497. @c the churn as Prosody updates.
  17498. Available @code{prosody-configuration} fields are:
  17499. @deftypevr {@code{prosody-configuration} parameter} package prosody
  17500. The Prosody package.
  17501. @end deftypevr
  17502. @deftypevr {@code{prosody-configuration} parameter} file-name data-path
  17503. Location of the Prosody data storage directory. See
  17504. @url{https://prosody.im/doc/configure}.
  17505. Defaults to @samp{"/var/lib/prosody"}.
  17506. @end deftypevr
  17507. @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
  17508. Additional plugin directories. They are searched in all the specified
  17509. paths in order. See @url{https://prosody.im/doc/plugins_directory}.
  17510. Defaults to @samp{()}.
  17511. @end deftypevr
  17512. @deftypevr {@code{prosody-configuration} parameter} file-name certificates
  17513. Every virtual host and component needs a certificate so that clients and
  17514. servers can securely verify its identity. Prosody will automatically load
  17515. certificates/keys from the directory specified here.
  17516. Defaults to @samp{"/etc/prosody/certs"}.
  17517. @end deftypevr
  17518. @deftypevr {@code{prosody-configuration} parameter} string-list admins
  17519. This is a list of accounts that are admins for the server. Note that you
  17520. must create the accounts separately. See @url{https://prosody.im/doc/admins} and
  17521. @url{https://prosody.im/doc/creating_accounts}.
  17522. Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
  17523. Defaults to @samp{()}.
  17524. @end deftypevr
  17525. @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
  17526. Enable use of libevent for better performance under high load. See
  17527. @url{https://prosody.im/doc/libevent}.
  17528. Defaults to @samp{#f}.
  17529. @end deftypevr
  17530. @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
  17531. This is the list of modules Prosody will load on startup. It looks for
  17532. @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
  17533. Documentation on modules can be found at:
  17534. @url{https://prosody.im/doc/modules}.
  17535. Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
  17536. @end deftypevr
  17537. @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
  17538. @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
  17539. should you want to disable them then add them to this list.
  17540. Defaults to @samp{()}.
  17541. @end deftypevr
  17542. @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
  17543. Path to a text file where the shared groups are defined. If this path is
  17544. empty then @samp{mod_groups} does nothing. See
  17545. @url{https://prosody.im/doc/modules/mod_groups}.
  17546. Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
  17547. @end deftypevr
  17548. @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
  17549. Disable account creation by default, for security. See
  17550. @url{https://prosody.im/doc/creating_accounts}.
  17551. Defaults to @samp{#f}.
  17552. @end deftypevr
  17553. @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
  17554. These are the SSL/TLS-related settings. Most of them are disabled so to
  17555. use Prosody's defaults. If you do not completely understand these options, do
  17556. not add them to your config, it is easy to lower the security of your server
  17557. using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
  17558. Available @code{ssl-configuration} fields are:
  17559. @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
  17560. This determines what handshake to use.
  17561. @end deftypevr
  17562. @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
  17563. Path to your private key file.
  17564. @end deftypevr
  17565. @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
  17566. Path to your certificate file.
  17567. @end deftypevr
  17568. @deftypevr {@code{ssl-configuration} parameter} file-object capath
  17569. Path to directory containing root certificates that you wish Prosody to
  17570. trust when verifying the certificates of remote servers.
  17571. Defaults to @samp{"/etc/ssl/certs"}.
  17572. @end deftypevr
  17573. @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
  17574. Path to a file containing root certificates that you wish Prosody to trust.
  17575. Similar to @code{capath} but with all certificates concatenated together.
  17576. @end deftypevr
  17577. @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
  17578. A list of verification options (these mostly map to OpenSSL's
  17579. @code{set_verify()} flags).
  17580. @end deftypevr
  17581. @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
  17582. A list of general options relating to SSL/TLS@. These map to OpenSSL's
  17583. @code{set_options()}. For a full list of options available in LuaSec, see the
  17584. LuaSec source.
  17585. @end deftypevr
  17586. @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
  17587. How long a chain of certificate authorities to check when looking for a
  17588. trusted root certificate.
  17589. @end deftypevr
  17590. @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
  17591. An OpenSSL cipher string. This selects what ciphers Prosody will offer to
  17592. clients, and in what order.
  17593. @end deftypevr
  17594. @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
  17595. A path to a file containing parameters for Diffie-Hellman key exchange. You
  17596. can create such a file with:
  17597. @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
  17598. @end deftypevr
  17599. @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
  17600. Curve for Elliptic curve Diffie-Hellman. Prosody's default is
  17601. @samp{"secp384r1"}.
  17602. @end deftypevr
  17603. @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
  17604. A list of ``extra'' verification options.
  17605. @end deftypevr
  17606. @deftypevr {@code{ssl-configuration} parameter} maybe-string password
  17607. Password for encrypted private keys.
  17608. @end deftypevr
  17609. @end deftypevr
  17610. @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
  17611. Whether to force all client-to-server connections to be encrypted or not.
  17612. See @url{https://prosody.im/doc/modules/mod_tls}.
  17613. Defaults to @samp{#f}.
  17614. @end deftypevr
  17615. @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
  17616. Set of mechanisms that will never be offered. See
  17617. @url{https://prosody.im/doc/modules/mod_saslauth}.
  17618. Defaults to @samp{("DIGEST-MD5")}.
  17619. @end deftypevr
  17620. @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
  17621. Whether to force all server-to-server connections to be encrypted or not.
  17622. See @url{https://prosody.im/doc/modules/mod_tls}.
  17623. Defaults to @samp{#f}.
  17624. @end deftypevr
  17625. @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
  17626. Whether to require encryption and certificate authentication. This
  17627. provides ideal security, but requires servers you communicate with to support
  17628. encryption AND present valid, trusted certificates. See
  17629. @url{https://prosody.im/doc/s2s#security}.
  17630. Defaults to @samp{#f}.
  17631. @end deftypevr
  17632. @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
  17633. Many servers don't support encryption or have invalid or self-signed
  17634. certificates. You can list domains here that will not be required to
  17635. authenticate using certificates. They will be authenticated using DNS@. See
  17636. @url{https://prosody.im/doc/s2s#security}.
  17637. Defaults to @samp{()}.
  17638. @end deftypevr
  17639. @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
  17640. Even if you leave @code{s2s-secure-auth?} disabled, you can still require
  17641. valid certificates for some domains by specifying a list here. See
  17642. @url{https://prosody.im/doc/s2s#security}.
  17643. Defaults to @samp{()}.
  17644. @end deftypevr
  17645. @deftypevr {@code{prosody-configuration} parameter} string authentication
  17646. Select the authentication backend to use. The default provider stores
  17647. passwords in plaintext and uses Prosody's configured data storage to store the
  17648. authentication data. If you do not trust your server please see
  17649. @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
  17650. about using the hashed backend. See also
  17651. @url{https://prosody.im/doc/authentication}
  17652. Defaults to @samp{"internal_plain"}.
  17653. @end deftypevr
  17654. @deftypevr {@code{prosody-configuration} parameter} maybe-string log
  17655. Set logging options. Advanced logging configuration is not yet supported
  17656. by the Prosody service. See @url{https://prosody.im/doc/logging}.
  17657. Defaults to @samp{"*syslog"}.
  17658. @end deftypevr
  17659. @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
  17660. File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
  17661. Defaults to @samp{"/var/run/prosody/prosody.pid"}.
  17662. @end deftypevr
  17663. @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
  17664. Maximum allowed size of the HTTP body (in bytes).
  17665. @end deftypevr
  17666. @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
  17667. Some modules expose their own URL in various ways. This URL is built
  17668. from the protocol, host and port used. If Prosody sits behind a proxy, the
  17669. public URL will be @code{http-external-url} instead. See
  17670. @url{https://prosody.im/doc/http#external_url}.
  17671. @end deftypevr
  17672. @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
  17673. A host in Prosody is a domain on which user accounts can be created. For
  17674. example if you want your users to have addresses like
  17675. @samp{"john.smith@@example.com"} then you need to add a host
  17676. @samp{"example.com"}. All options in this list will apply only to this host.
  17677. Note: the name @emph{virtual} host is used in configuration to avoid confusion with
  17678. the actual physical host that Prosody is installed on. A single Prosody
  17679. instance can serve many domains, each one defined as a VirtualHost entry in
  17680. Prosody's configuration. Conversely a server that hosts a single domain would
  17681. have just one VirtualHost entry.
  17682. See @url{https://prosody.im/doc/configure#virtual_host_settings}.
  17683. Available @code{virtualhost-configuration} fields are:
  17684. all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
  17685. @deftypevr {@code{virtualhost-configuration} parameter} string domain
  17686. Domain you wish Prosody to serve.
  17687. @end deftypevr
  17688. @end deftypevr
  17689. @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
  17690. Components are extra services on a server which are available to clients,
  17691. usually on a subdomain of the main server (such as
  17692. @samp{"mycomponent.example.com"}). Example components might be chatroom
  17693. servers, user directories, or gateways to other protocols.
  17694. Internal components are implemented with Prosody-specific plugins. To add an
  17695. internal component, you simply fill the hostname field, and the plugin you wish
  17696. to use for the component.
  17697. See @url{https://prosody.im/doc/components}.
  17698. Defaults to @samp{()}.
  17699. Available @code{int-component-configuration} fields are:
  17700. all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
  17701. @deftypevr {@code{int-component-configuration} parameter} string hostname
  17702. Hostname of the component.
  17703. @end deftypevr
  17704. @deftypevr {@code{int-component-configuration} parameter} string plugin
  17705. Plugin you wish to use for the component.
  17706. @end deftypevr
  17707. @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
  17708. Multi-user chat (MUC) is Prosody's module for allowing you to create
  17709. hosted chatrooms/conferences for XMPP users.
  17710. General information on setting up and using multi-user chatrooms can be found
  17711. in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
  17712. which you should read if you are new to XMPP chatrooms.
  17713. See also @url{https://prosody.im/doc/modules/mod_muc}.
  17714. Available @code{mod-muc-configuration} fields are:
  17715. @deftypevr {@code{mod-muc-configuration} parameter} string name
  17716. The name to return in service discovery responses.
  17717. Defaults to @samp{"Prosody Chatrooms"}.
  17718. @end deftypevr
  17719. @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
  17720. If @samp{#t}, this will only allow admins to create new chatrooms.
  17721. Otherwise anyone can create a room. The value @samp{"local"} restricts room
  17722. creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
  17723. can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
  17724. restricts to service administrators only.
  17725. Defaults to @samp{#f}.
  17726. @end deftypevr
  17727. @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
  17728. Maximum number of history messages that will be sent to the member that has
  17729. just joined the room.
  17730. Defaults to @samp{20}.
  17731. @end deftypevr
  17732. @end deftypevr
  17733. @end deftypevr
  17734. @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
  17735. External components use XEP-0114, which most standalone components
  17736. support. To add an external component, you simply fill the hostname field. See
  17737. @url{https://prosody.im/doc/components}.
  17738. Defaults to @samp{()}.
  17739. Available @code{ext-component-configuration} fields are:
  17740. all these @code{prosody-configuration} fields: @code{admins}, @code{use-libevent?}, @code{modules-enabled}, @code{modules-disabled}, @code{groups-file}, @code{allow-registration?}, @code{ssl}, @code{c2s-require-encryption?}, @code{disable-sasl-mechanisms}, @code{s2s-require-encryption?}, @code{s2s-secure-auth?}, @code{s2s-insecure-domains}, @code{s2s-secure-domains}, @code{authentication}, @code{log}, @code{http-max-content-size}, @code{http-external-url}, @code{raw-content}, plus:
  17741. @deftypevr {@code{ext-component-configuration} parameter} string component-secret
  17742. Password which the component will use to log in.
  17743. @end deftypevr
  17744. @deftypevr {@code{ext-component-configuration} parameter} string hostname
  17745. Hostname of the component.
  17746. @end deftypevr
  17747. @end deftypevr
  17748. @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
  17749. Port(s) Prosody listens on for component connections.
  17750. Defaults to @samp{(5347)}.
  17751. @end deftypevr
  17752. @deftypevr {@code{prosody-configuration} parameter} string component-interface
  17753. Interface Prosody listens on for component connections.
  17754. Defaults to @samp{"127.0.0.1"}.
  17755. @end deftypevr
  17756. @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
  17757. Raw content that will be added to the configuration file.
  17758. @end deftypevr
  17759. It could be that you just want to get a @code{prosody.cfg.lua}
  17760. up and running. In that case, you can pass an
  17761. @code{opaque-prosody-configuration} record as the value of
  17762. @code{prosody-service-type}. As its name indicates, an opaque configuration
  17763. does not have easy reflective capabilities.
  17764. Available @code{opaque-prosody-configuration} fields are:
  17765. @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
  17766. The prosody package.
  17767. @end deftypevr
  17768. @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
  17769. The contents of the @code{prosody.cfg.lua} to use.
  17770. @end deftypevr
  17771. For example, if your @code{prosody.cfg.lua} is just the empty
  17772. string, you could instantiate a prosody service like this:
  17773. @lisp
  17774. (service prosody-service-type
  17775. (opaque-prosody-configuration
  17776. (prosody.cfg.lua "")))
  17777. @end lisp
  17778. @c end of Prosody auto-generated documentation
  17779. @subsubheading BitlBee Service
  17780. @cindex IRC (Internet Relay Chat)
  17781. @cindex IRC gateway
  17782. @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
  17783. interface to a variety of messaging protocols such as XMPP.
  17784. @defvr {Scheme Variable} bitlbee-service-type
  17785. This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
  17786. gateway daemon. Its value is a @code{bitlbee-configuration} (see
  17787. below).
  17788. To have BitlBee listen on port 6667 on localhost, add this line to your
  17789. services:
  17790. @lisp
  17791. (service bitlbee-service-type)
  17792. @end lisp
  17793. @end defvr
  17794. @deftp {Data Type} bitlbee-configuration
  17795. This is the configuration for BitlBee, with the following fields:
  17796. @table @asis
  17797. @item @code{interface} (default: @code{"127.0.0.1"})
  17798. @itemx @code{port} (default: @code{6667})
  17799. Listen on the network interface corresponding to the IP address
  17800. specified in @var{interface}, on @var{port}.
  17801. When @var{interface} is @code{127.0.0.1}, only local clients can
  17802. connect; when it is @code{0.0.0.0}, connections can come from any
  17803. networking interface.
  17804. @item @code{bitlbee} (default: @code{bitlbee})
  17805. The BitlBee package to use.
  17806. @item @code{plugins} (default: @code{'()})
  17807. List of plugin packages to use---e.g., @code{bitlbee-discord}.
  17808. @item @code{extra-settings} (default: @code{""})
  17809. Configuration snippet added as-is to the BitlBee configuration file.
  17810. @end table
  17811. @end deftp
  17812. @subsubheading Quassel Service
  17813. @cindex IRC (Internet Relay Chat)
  17814. @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
  17815. meaning that one or more clients can attach to and detach from the
  17816. central core.
  17817. @defvr {Scheme Variable} quassel-service-type
  17818. This is the service type for the @url{https://quassel-irc.org/,Quassel}
  17819. IRC backend daemon. Its value is a @code{quassel-configuration}
  17820. (see below).
  17821. @end defvr
  17822. @deftp {Data Type} quassel-configuration
  17823. This is the configuration for Quassel, with the following fields:
  17824. @table @asis
  17825. @item @code{quassel} (default: @code{quassel})
  17826. The Quassel package to use.
  17827. @item @code{interface} (default: @code{"::,0.0.0.0"})
  17828. @item @code{port} (default: @code{4242})
  17829. Listen on the network interface(s) corresponding to the IPv4 or IPv6
  17830. interfaces specified in the comma delimited @var{interface}, on
  17831. @var{port}.
  17832. @item @code{loglevel} (default: @code{"Info"})
  17833. The level of logging desired. Accepted values are Debug, Info, Warning
  17834. and Error.
  17835. @end table
  17836. @end deftp
  17837. @node Telephony Services
  17838. @subsection Telephony Services
  17839. @cindex Murmur (VoIP server)
  17840. @cindex VoIP server
  17841. This section describes how to set up and run a Murmur server. Murmur is
  17842. the server of the @uref{https://mumble.info, Mumble} voice-over-IP
  17843. (VoIP) suite.
  17844. @deftp {Data Type} murmur-configuration
  17845. The service type for the Murmur server. An example configuration can
  17846. look like this:
  17847. @lisp
  17848. (service murmur-service-type
  17849. (murmur-configuration
  17850. (welcome-text
  17851. "Welcome to this Mumble server running on Guix!")
  17852. (cert-required? #t) ;disallow text password logins
  17853. (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
  17854. (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
  17855. @end lisp
  17856. After reconfiguring your system, you can manually set the murmur @code{SuperUser}
  17857. password with the command that is printed during the activation phase.
  17858. It is recommended to register a normal Mumble user account
  17859. and grant it admin or moderator rights.
  17860. You can use the @code{mumble} client to
  17861. login as new normal user, register yourself, and log out.
  17862. For the next step login with the name @code{SuperUser} use
  17863. the @code{SuperUser} password that you set previously,
  17864. and grant your newly registered mumble user administrator or moderator
  17865. rights and create some channels.
  17866. Available @code{murmur-configuration} fields are:
  17867. @table @asis
  17868. @item @code{package} (default: @code{mumble})
  17869. Package that contains @code{bin/murmurd}.
  17870. @item @code{user} (default: @code{"murmur"})
  17871. User who will run the Murmur server.
  17872. @item @code{group} (default: @code{"murmur"})
  17873. Group of the user who will run the murmur server.
  17874. @item @code{port} (default: @code{64738})
  17875. Port on which the server will listen.
  17876. @item @code{welcome-text} (default: @code{""})
  17877. Welcome text sent to clients when they connect.
  17878. @item @code{server-password} (default: @code{""})
  17879. Password the clients have to enter in order to connect.
  17880. @item @code{max-users} (default: @code{100})
  17881. Maximum of users that can be connected to the server at once.
  17882. @item @code{max-user-bandwidth} (default: @code{#f})
  17883. Maximum voice traffic a user can send per second.
  17884. @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
  17885. File name of the sqlite database.
  17886. The service's user will become the owner of the directory.
  17887. @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
  17888. File name of the log file.
  17889. The service's user will become the owner of the directory.
  17890. @item @code{autoban-attempts} (default: @code{10})
  17891. Maximum number of logins a user can make in @code{autoban-timeframe}
  17892. without getting auto banned for @code{autoban-time}.
  17893. @item @code{autoban-timeframe} (default: @code{120})
  17894. Timeframe for autoban in seconds.
  17895. @item @code{autoban-time} (default: @code{300})
  17896. Amount of time in seconds for which a client gets banned
  17897. when violating the autoban limits.
  17898. @item @code{opus-threshold} (default: @code{100})
  17899. Percentage of clients that need to support opus
  17900. before switching over to opus audio codec.
  17901. @item @code{channel-nesting-limit} (default: @code{10})
  17902. How deep channels can be nested at maximum.
  17903. @item @code{channelname-regex} (default: @code{#f})
  17904. A string in form of a Qt regular expression that channel names must conform to.
  17905. @item @code{username-regex} (default: @code{#f})
  17906. A string in form of a Qt regular expression that user names must conform to.
  17907. @item @code{text-message-length} (default: @code{5000})
  17908. Maximum size in bytes that a user can send in one text chat message.
  17909. @item @code{image-message-length} (default: @code{(* 128 1024)})
  17910. Maximum size in bytes that a user can send in one image message.
  17911. @item @code{cert-required?} (default: @code{#f})
  17912. If it is set to @code{#t} clients that use weak password authentication
  17913. will not be accepted. Users must have completed the certificate wizard to join.
  17914. @item @code{remember-channel?} (default: @code{#f})
  17915. Should murmur remember the last channel each user was in when they disconnected
  17916. and put them into the remembered channel when they rejoin.
  17917. @item @code{allow-html?} (default: @code{#f})
  17918. Should html be allowed in text messages, user comments, and channel descriptions.
  17919. @item @code{allow-ping?} (default: @code{#f})
  17920. Setting to true exposes the current user count, the maximum user count, and
  17921. the server's maximum bandwidth per client to unauthenticated users. In the
  17922. Mumble client, this information is shown in the Connect dialog.
  17923. Disabling this setting will prevent public listing of the server.
  17924. @item @code{bonjour?} (default: @code{#f})
  17925. Should the server advertise itself in the local network through the bonjour protocol.
  17926. @item @code{send-version?} (default: @code{#f})
  17927. Should the murmur server version be exposed in ping requests.
  17928. @item @code{log-days} (default: @code{31})
  17929. Murmur also stores logs in the database, which are accessible via RPC.
  17930. The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
  17931. or -1 to disable logging to the database.
  17932. @item @code{obfuscate-ips?} (default: @code{#t})
  17933. Should logged ips be obfuscated to protect the privacy of users.
  17934. @item @code{ssl-cert} (default: @code{#f})
  17935. File name of the SSL/TLS certificate used for encrypted connections.
  17936. @lisp
  17937. (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
  17938. @end lisp
  17939. @item @code{ssl-key} (default: @code{#f})
  17940. Filepath to the ssl private key used for encrypted connections.
  17941. @lisp
  17942. (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
  17943. @end lisp
  17944. @item @code{ssl-dh-params} (default: @code{#f})
  17945. File name of a PEM-encoded file with Diffie-Hellman parameters
  17946. for the SSL/TLS encryption. Alternatively you set it to
  17947. @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
  17948. or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
  17949. @item @code{ssl-ciphers} (default: @code{#f})
  17950. The @code{ssl-ciphers} option chooses the cipher suites to make available for use
  17951. in SSL/TLS.
  17952. This option is specified using
  17953. @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
  17954. OpenSSL cipher list notation}.
  17955. It is recommended that you try your cipher string using 'openssl ciphers <string>'
  17956. before setting it here, to get a feel for which cipher suites you will get.
  17957. After setting this option, it is recommend that you inspect your Murmur log
  17958. to ensure that Murmur is using the cipher suites that you expected it to.
  17959. Note: Changing this option may impact the backwards compatibility of your
  17960. Murmur server, and can remove the ability for older Mumble clients to be able
  17961. to connect to it.
  17962. @item @code{public-registration} (default: @code{#f})
  17963. Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
  17964. You can optionally register your server in the public server list that the
  17965. @code{mumble} client shows on startup.
  17966. You cannot register your server if you have set a @code{server-password},
  17967. or set @code{allow-ping} to @code{#f}.
  17968. It might take a few hours until it shows up in the public list.
  17969. @item @code{file} (default: @code{#f})
  17970. Optional alternative override for this configuration.
  17971. @end table
  17972. @end deftp
  17973. @deftp {Data Type} murmur-public-registration-configuration
  17974. Configuration for public registration of a murmur service.
  17975. @table @asis
  17976. @item @code{name}
  17977. This is a display name for your server. Not to be confused with the hostname.
  17978. @item @code{password}
  17979. A password to identify your registration.
  17980. Subsequent updates will need the same password. Don't lose your password.
  17981. @item @code{url}
  17982. This should be a @code{http://} or @code{https://} link to your web
  17983. site.
  17984. @item @code{hostname} (default: @code{#f})
  17985. By default your server will be listed by its IP address.
  17986. If it is set your server will be linked by this host name instead.
  17987. @end table
  17988. @end deftp
  17989. @node File-Sharing Services
  17990. @subsection File-Sharing Services
  17991. The @code{(gnu services file-sharing)} module provides services that
  17992. assist with transferring files over peer-to-peer file-sharing networks.
  17993. @subsubheading Transmission Daemon Service
  17994. @uref{https://transmissionbt.com/, Transmission} is a flexible
  17995. BitTorrent client that offers a variety of graphical and command-line
  17996. interfaces. A @code{transmission-daemon-service-type} service provides
  17997. Transmission's headless variant, @command{transmission-daemon}, as a
  17998. system service, allowing users to share files via BitTorrent even when
  17999. they are not logged in.
  18000. @deffn {Scheme Variable} transmission-daemon-service-type
  18001. The service type for the Transmission Daemon BitTorrent client. Its
  18002. value must be a @code{transmission-daemon-configuration} object as in
  18003. this example:
  18004. @lisp
  18005. (service transmission-daemon-service-type
  18006. (transmission-daemon-configuration
  18007. ;; Restrict access to the RPC ("control") interface
  18008. (rpc-authentication-required? #t)
  18009. (rpc-username "transmission")
  18010. (rpc-password
  18011. (transmission-password-hash
  18012. "transmission" ; desired password
  18013. "uKd1uMs9")) ; arbitrary salt value
  18014. ;; Accept requests from this and other hosts on the
  18015. ;; local network
  18016. (rpc-whitelist-enabled? #t)
  18017. (rpc-whitelist '("::1" "127.0.0.1" "192.168.0.*"))
  18018. ;; Limit bandwidth use during work hours
  18019. (alt-speed-down (* 1024 2)) ; 2 MB/s
  18020. (alt-speed-up 512) ; 512 kB/s
  18021. (alt-speed-time-enabled? #t)
  18022. (alt-speed-time-day 'weekdays)
  18023. (alt-speed-time-begin
  18024. (+ (* 60 8) 30)) ; 8:30 am
  18025. (alt-speed-time-end
  18026. (+ (* 60 (+ 12 5)) 30)))) ; 5:30 pm
  18027. @end lisp
  18028. @end deffn
  18029. Once the service is started, users can interact with the daemon through
  18030. its Web interface (at @code{http://localhost:9091/}) or by using the
  18031. @command{transmission-remote} command-line tool, available in the
  18032. @code{transmission} package. (Emacs users may want to also consider the
  18033. @code{emacs-transmission} package.) Both communicate with the daemon
  18034. through its remote procedure call (RPC) interface, which by default is
  18035. available to all users on the system; you may wish to change this by
  18036. assigning values to the @code{rpc-authentication-required?},
  18037. @code{rpc-username} and @code{rpc-password} settings, as shown in the
  18038. example above and documented further below.
  18039. The value for @code{rpc-password} must be a password hash of the type
  18040. generated and used by Transmission clients. This can be copied verbatim
  18041. from an existing @file{settings.json} file, if another Transmission
  18042. client is already being used. Otherwise, the
  18043. @code{transmission-password-hash} and @code{transmission-random-salt}
  18044. procedures provided by this module can be used to obtain a suitable hash
  18045. value.
  18046. @deffn {Scheme Procedure} transmission-password-hash @var{password} @var{salt}
  18047. Returns a string containing the result of hashing @var{password}
  18048. together with @var{salt}, in the format recognized by Transmission
  18049. clients for their @code{rpc-password} configuration setting.
  18050. @var{salt} must be an eight-character string. The
  18051. @code{transmission-random-salt} procedure can be used to generate a
  18052. suitable salt value at random.
  18053. @end deffn
  18054. @deffn {Scheme Procedure} transmission-random-salt
  18055. Returns a string containing a random, eight-character salt value of the
  18056. type generated and used by Transmission clients, suitable for passing to
  18057. the @code{transmission-password-hash} procedure.
  18058. @end deffn
  18059. These procedures are accessible from within a Guile REPL started with
  18060. the @command{guix repl} command (@pxref{Invoking guix repl}). This is
  18061. useful for obtaining a random salt value to provide as the second
  18062. parameter to `transmission-password-hash`, as in this example session:
  18063. @example
  18064. $ guix repl
  18065. scheme@@(guix-user)> ,use (gnu services file-sharing)
  18066. scheme@@(guix-user)> (transmission-random-salt)
  18067. $1 = "uKd1uMs9"
  18068. @end example
  18069. Alternatively, a complete password hash can generated in a single step:
  18070. @example
  18071. scheme@@(guix-user)> (transmission-password-hash "transmission"
  18072. (transmission-random-salt))
  18073. $2 = "@{c8bbc6d1740cd8dc819a6e25563b67812c1c19c9VtFPfdsX"
  18074. @end example
  18075. The resulting string can be used as-is for the value of
  18076. @code{rpc-password}, allowing the password to be kept hidden even in the
  18077. operating-system configuration.
  18078. Torrent files downloaded by the daemon are directly accessible only to
  18079. users in the ``transmission'' user group, who receive read-only access
  18080. to the directory specified by the @code{download-dir} configuration
  18081. setting (and also the directory specified by @code{incomplete-dir}, if
  18082. @code{incomplete-dir-enabled?} is @code{#t}). Downloaded files can be
  18083. moved to another directory or deleted altogether using
  18084. @command{transmission-remote} with its @code{--move} and
  18085. @code{--remove-and-delete} options.
  18086. If the @code{watch-dir-enabled?} setting is set to @code{#t}, users in
  18087. the ``transmission'' group are able also to place @file{.torrent} files
  18088. in the directory specified by @code{watch-dir} to have the corresponding
  18089. torrents added by the daemon. (The @code{trash-original-torrent-files?}
  18090. setting controls whether the daemon deletes these files after processing
  18091. them.)
  18092. Some of the daemon's configuration settings can be changed temporarily
  18093. by @command{transmission-remote} and similar tools. To undo these
  18094. changes, use the service's @code{reload} action to have the daemon
  18095. reload its settings from disk:
  18096. @example
  18097. # herd reload transmission-daemon
  18098. @end example
  18099. The full set of available configuration settings is defined by the
  18100. @code{transmission-daemon-configuration} data type.
  18101. @deftp {Data Type} transmission-daemon-configuration
  18102. The data type representing configuration settings for Transmission
  18103. Daemon. These correspond directly to the settings recognized by
  18104. Transmission clients in their @file{settings.json} file.
  18105. @end deftp
  18106. @c The following documentation was initially generated by
  18107. @c (generate-transmission-daemon-documentation) in (gnu services
  18108. @c file-sharing). Manually maintained documentation is better, so we
  18109. @c shouldn't hesitate to edit below as needed. However if the change
  18110. @c you want to make to this documentation can be done in an automated
  18111. @c way, it's probably easier to change (generate-documentation) than to
  18112. @c make it below and have to deal with the churn as Transmission Daemon
  18113. @c updates.
  18114. @c %start of fragment
  18115. Available @code{transmission-daemon-configuration} fields are:
  18116. @deftypevr {@code{transmission-daemon-configuration} parameter} package transmission
  18117. The Transmission package to use.
  18118. @end deftypevr
  18119. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer stop-wait-period
  18120. The period, in seconds, to wait when stopping the service for
  18121. @command{transmission-daemon} to exit before killing its process. This
  18122. allows the daemon time to complete its housekeeping and send a final
  18123. update to trackers as it shuts down. On slow hosts, or hosts with a
  18124. slow network connection, this value may need to be increased.
  18125. Defaults to @samp{10}.
  18126. @end deftypevr
  18127. @deftypevr {@code{transmission-daemon-configuration} parameter} string download-dir
  18128. The directory to which torrent files are downloaded.
  18129. Defaults to @samp{"/var/lib/transmission-daemon/downloads"}.
  18130. @end deftypevr
  18131. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean incomplete-dir-enabled?
  18132. If @code{#t}, files will be held in @code{incomplete-dir} while their
  18133. torrent is being downloaded, then moved to @code{download-dir} once the
  18134. torrent is complete. Otherwise, files for all torrents (including those
  18135. still being downloaded) will be placed in @code{download-dir}.
  18136. Defaults to @samp{#f}.
  18137. @end deftypevr
  18138. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string incomplete-dir
  18139. The directory in which files from incompletely downloaded torrents will
  18140. be held when @code{incomplete-dir-enabled?} is @code{#t}.
  18141. Defaults to @samp{disabled}.
  18142. @end deftypevr
  18143. @deftypevr {@code{transmission-daemon-configuration} parameter} umask umask
  18144. The file mode creation mask used for downloaded files. (See the
  18145. @command{umask} man page for more information.)
  18146. Defaults to @samp{18}.
  18147. @end deftypevr
  18148. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rename-partial-files?
  18149. When @code{#t}, ``.part'' is appended to the name of partially
  18150. downloaded files.
  18151. Defaults to @samp{#t}.
  18152. @end deftypevr
  18153. @deftypevr {@code{transmission-daemon-configuration} parameter} preallocation-mode preallocation
  18154. The mode by which space should be preallocated for downloaded files, one
  18155. of @code{none}, @code{fast} (or @code{sparse}) and @code{full}.
  18156. Specifying @code{full} will minimize disk fragmentation at a cost to
  18157. file-creation speed.
  18158. Defaults to @samp{fast}.
  18159. @end deftypevr
  18160. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean watch-dir-enabled?
  18161. If @code{#t}, the directory specified by @code{watch-dir} will be
  18162. watched for new @file{.torrent} files and the torrents they describe
  18163. added automatically (and the original files removed, if
  18164. @code{trash-original-torrent-files?} is @code{#t}).
  18165. Defaults to @samp{#f}.
  18166. @end deftypevr
  18167. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string watch-dir
  18168. The directory to be watched for @file{.torrent} files indicating new
  18169. torrents to be added, when @code{watch-dir-enabled} is @code{#t}.
  18170. Defaults to @samp{disabled}.
  18171. @end deftypevr
  18172. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean trash-original-torrent-files?
  18173. When @code{#t}, @file{.torrent} files will be deleted from the watch
  18174. directory once their torrent has been added (see
  18175. @code{watch-directory-enabled?}).
  18176. Defaults to @samp{#f}.
  18177. @end deftypevr
  18178. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-down-enabled?
  18179. When @code{#t}, the daemon's download speed will be limited to the rate
  18180. specified by @code{speed-limit-down}.
  18181. Defaults to @samp{#f}.
  18182. @end deftypevr
  18183. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-down
  18184. The default global-maximum download speed, in kilobytes per second.
  18185. Defaults to @samp{100}.
  18186. @end deftypevr
  18187. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-up-enabled?
  18188. When @code{#t}, the daemon's upload speed will be limited to the rate
  18189. specified by @code{speed-limit-up}.
  18190. Defaults to @samp{#f}.
  18191. @end deftypevr
  18192. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-up
  18193. The default global-maximum upload speed, in kilobytes per second.
  18194. Defaults to @samp{100}.
  18195. @end deftypevr
  18196. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-enabled?
  18197. When @code{#t}, the alternate speed limits @code{alt-speed-down} and
  18198. @code{alt-speed-up} are used (in place of @code{speed-limit-down} and
  18199. @code{speed-limit-up}, if they are enabled) to constrain the daemon's
  18200. bandwidth usage. This can be scheduled to occur automatically at
  18201. certain times during the week; see @code{alt-speed-time-enabled?}.
  18202. Defaults to @samp{#f}.
  18203. @end deftypevr
  18204. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-down
  18205. The alternate global-maximum download speed, in kilobytes per second.
  18206. Defaults to @samp{50}.
  18207. @end deftypevr
  18208. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-up
  18209. The alternate global-maximum upload speed, in kilobytes per second.
  18210. Defaults to @samp{50}.
  18211. @end deftypevr
  18212. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-time-enabled?
  18213. When @code{#t}, the alternate speed limits @code{alt-speed-down} and
  18214. @code{alt-speed-up} will be enabled automatically during the periods
  18215. specified by @code{alt-speed-time-day}, @code{alt-speed-time-begin} and
  18216. @code{alt-time-speed-end}.
  18217. Defaults to @samp{#f}.
  18218. @end deftypevr
  18219. @deftypevr {@code{transmission-daemon-configuration} parameter} day-list alt-speed-time-day
  18220. The days of the week on which the alternate-speed schedule should be
  18221. used, specified either as a list of days (@code{sunday}, @code{monday},
  18222. and so on) or using one of the symbols @code{weekdays}, @code{weekends}
  18223. or @code{all}.
  18224. Defaults to @samp{all}.
  18225. @end deftypevr
  18226. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-begin
  18227. The time of day at which to enable the alternate speed limits, expressed
  18228. as a number of minutes since midnight.
  18229. Defaults to @samp{540}.
  18230. @end deftypevr
  18231. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-end
  18232. The time of day at which to disable the alternate speed limits,
  18233. expressed as a number of minutes since midnight.
  18234. Defaults to @samp{1020}.
  18235. @end deftypevr
  18236. @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv4
  18237. The IP address at which to listen for peer connections, or ``0.0.0.0''
  18238. to listen at all available IP addresses.
  18239. Defaults to @samp{"0.0.0.0"}.
  18240. @end deftypevr
  18241. @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv6
  18242. The IPv6 address at which to listen for peer connections, or ``::'' to
  18243. listen at all available IPv6 addresses.
  18244. Defaults to @samp{"::"}.
  18245. @end deftypevr
  18246. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean peer-port-random-on-start?
  18247. If @code{#t}, when the daemon starts it will select a port at random on
  18248. which to listen for peer connections, from the range specified
  18249. (inclusively) by @code{peer-port-random-low} and
  18250. @code{peer-port-random-high}. Otherwise, it listens on the port
  18251. specified by @code{peer-port}.
  18252. Defaults to @samp{#f}.
  18253. @end deftypevr
  18254. @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-low
  18255. The lowest selectable port number when @code{peer-port-random-on-start?}
  18256. is @code{#t}.
  18257. Defaults to @samp{49152}.
  18258. @end deftypevr
  18259. @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-high
  18260. The highest selectable port number when @code{peer-port-random-on-start}
  18261. is @code{#t}.
  18262. Defaults to @samp{65535}.
  18263. @end deftypevr
  18264. @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port
  18265. The port on which to listen for peer connections when
  18266. @code{peer-port-random-on-start?} is @code{#f}.
  18267. Defaults to @samp{51413}.
  18268. @end deftypevr
  18269. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean port-forwarding-enabled?
  18270. If @code{#t}, the daemon will attempt to configure port-forwarding on an
  18271. upstream gateway automatically using @acronym{UPnP} and
  18272. @acronym{NAT-PMP}.
  18273. Defaults to @samp{#t}.
  18274. @end deftypevr
  18275. @deftypevr {@code{transmission-daemon-configuration} parameter} encryption-mode encryption
  18276. The encryption preference for peer connections, one of
  18277. @code{prefer-unencrypted-connections},
  18278. @code{prefer-encrypted-connections} or
  18279. @code{require-encrypted-connections}.
  18280. Defaults to @samp{prefer-encrypted-connections}.
  18281. @end deftypevr
  18282. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string peer-congestion-algorithm
  18283. The TCP congestion-control algorithm to use for peer connections,
  18284. specified using a string recognized by the operating system in calls to
  18285. @code{setsockopt} (or set to @code{disabled}, in which case the
  18286. operating-system default is used).
  18287. Note that on GNU/Linux systems, the kernel must be configured to allow
  18288. processes to use a congestion-control algorithm not in the default set;
  18289. otherwise, it will deny these requests with ``Operation not permitted''.
  18290. To see which algorithms are available on your system and which are
  18291. currently permitted for use, look at the contents of the files
  18292. @file{tcp_available_congestion_control} and
  18293. @file{tcp_allowed_congestion_control} in the @file{/proc/sys/net/ipv4}
  18294. directory.
  18295. As an example, to have Transmission Daemon use
  18296. @uref{http://www-ece.rice.edu/networks/TCP-LP/,the TCP Low Priority
  18297. congestion-control algorithm}, you'll need to modify your kernel
  18298. configuration to build in support for the algorithm, then update your
  18299. operating-system configuration to allow its use by adding a
  18300. @code{sysctl-service-type} service (or updating the existing one's
  18301. configuration) with lines like the following:
  18302. @lisp
  18303. (service sysctl-service-type
  18304. (sysctl-configuration
  18305. (settings
  18306. ("net.ipv4.tcp_allowed_congestion_control" .
  18307. "reno cubic lp"))))
  18308. @end lisp
  18309. The Transmission Daemon configuration can then be updated with
  18310. @lisp
  18311. (peer-congestion-algorithm "lp")
  18312. @end lisp
  18313. and the system reconfigured to have the changes take effect.
  18314. Defaults to @samp{disabled}.
  18315. @end deftypevr
  18316. @deftypevr {@code{transmission-daemon-configuration} parameter} tcp-type-of-service peer-socket-tos
  18317. The type of service to request in outgoing @acronym{TCP} packets, one of
  18318. @code{default}, @code{low-cost}, @code{throughput}, @code{low-delay} and
  18319. @code{reliability}.
  18320. Defaults to @samp{default}.
  18321. @end deftypevr
  18322. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-global
  18323. The global limit on the number of connected peers.
  18324. Defaults to @samp{200}.
  18325. @end deftypevr
  18326. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-per-torrent
  18327. The per-torrent limit on the number of connected peers.
  18328. Defaults to @samp{50}.
  18329. @end deftypevr
  18330. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer upload-slots-per-torrent
  18331. The maximum number of peers to which the daemon will upload data
  18332. simultaneously for each torrent.
  18333. Defaults to @samp{14}.
  18334. @end deftypevr
  18335. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-id-ttl-hours
  18336. The maximum lifespan, in hours, of the peer ID associated with each
  18337. public torrent before it is regenerated.
  18338. Defaults to @samp{6}.
  18339. @end deftypevr
  18340. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean blocklist-enabled?
  18341. When @code{#t}, the daemon will ignore peers mentioned in the blocklist
  18342. it has most recently downloaded from @code{blocklist-url}.
  18343. Defaults to @samp{#f}.
  18344. @end deftypevr
  18345. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string blocklist-url
  18346. The URL of a peer blocklist (in @acronym{P2P}-plaintext or eMule
  18347. @file{.dat} format) to be periodically downloaded and applied when
  18348. @code{blocklist-enabled?} is @code{#t}.
  18349. Defaults to @samp{disabled}.
  18350. @end deftypevr
  18351. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean download-queue-enabled?
  18352. If @code{#t}, the daemon will be limited to downloading at most
  18353. @code{download-queue-size} non-stalled torrents simultaneously.
  18354. Defaults to @samp{#t}.
  18355. @end deftypevr
  18356. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer download-queue-size
  18357. The size of the daemon's download queue, which limits the number of
  18358. non-stalled torrents it will download at any one time when
  18359. @code{download-queue-enabled?} is @code{#t}.
  18360. Defaults to @samp{5}.
  18361. @end deftypevr
  18362. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean seed-queue-enabled?
  18363. If @code{#t}, the daemon will be limited to seeding at most
  18364. @code{seed-queue-size} non-stalled torrents simultaneously.
  18365. Defaults to @samp{#f}.
  18366. @end deftypevr
  18367. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer seed-queue-size
  18368. The size of the daemon's seed queue, which limits the number of
  18369. non-stalled torrents it will seed at any one time when
  18370. @code{seed-queue-enabled?} is @code{#t}.
  18371. Defaults to @samp{10}.
  18372. @end deftypevr
  18373. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean queue-stalled-enabled?
  18374. When @code{#t}, the daemon will consider torrents for which it has not
  18375. shared data in the past @code{queue-stalled-minutes} minutes to be
  18376. stalled and not count them against its @code{download-queue-size} and
  18377. @code{seed-queue-size} limits.
  18378. Defaults to @samp{#t}.
  18379. @end deftypevr
  18380. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer queue-stalled-minutes
  18381. The maximum period, in minutes, a torrent may be idle before it is
  18382. considered to be stalled, when @code{queue-stalled-enabled?} is
  18383. @code{#t}.
  18384. Defaults to @samp{30}.
  18385. @end deftypevr
  18386. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean ratio-limit-enabled?
  18387. When @code{#t}, a torrent being seeded will automatically be paused once
  18388. it reaches the ratio specified by @code{ratio-limit}.
  18389. Defaults to @samp{#f}.
  18390. @end deftypevr
  18391. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-rational ratio-limit
  18392. The ratio at which a torrent being seeded will be paused, when
  18393. @code{ratio-limit-enabled?} is @code{#t}.
  18394. Defaults to @samp{2.0}.
  18395. @end deftypevr
  18396. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean idle-seeding-limit-enabled?
  18397. When @code{#t}, a torrent being seeded will automatically be paused once
  18398. it has been idle for @code{idle-seeding-limit} minutes.
  18399. Defaults to @samp{#f}.
  18400. @end deftypevr
  18401. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer idle-seeding-limit
  18402. The maximum period, in minutes, a torrent being seeded may be idle
  18403. before it is paused, when @code{idle-seeding-limit-enabled?} is
  18404. @code{#t}.
  18405. Defaults to @samp{30}.
  18406. @end deftypevr
  18407. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean dht-enabled?
  18408. Enable @uref{http://bittorrent.org/beps/bep_0005.html,the distributed
  18409. hash table (@acronym{DHT}) protocol}, which supports the use of
  18410. trackerless torrents.
  18411. Defaults to @samp{#t}.
  18412. @end deftypevr
  18413. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean lpd-enabled?
  18414. Enable @uref{https://en.wikipedia.org/wiki/Local_Peer_Discovery,local
  18415. peer discovery} (@acronym{LPD}), which allows the discovery of peers on
  18416. the local network and may reduce the amount of data sent over the public
  18417. Internet.
  18418. Defaults to @samp{#f}.
  18419. @end deftypevr
  18420. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean pex-enabled?
  18421. Enable @uref{https://en.wikipedia.org/wiki/Peer_exchange,peer exchange}
  18422. (@acronym{PEX}), which reduces the daemon's reliance on external
  18423. trackers and may improve its performance.
  18424. Defaults to @samp{#t}.
  18425. @end deftypevr
  18426. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean utp-enabled?
  18427. Enable @uref{http://bittorrent.org/beps/bep_0029.html,the micro
  18428. transport protocol} (@acronym{uTP}), which aims to reduce the impact of
  18429. BitTorrent traffic on other users of the local network while maintaining
  18430. full utilization of the available bandwidth.
  18431. Defaults to @samp{#t}.
  18432. @end deftypevr
  18433. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-enabled?
  18434. If @code{#t}, enable the remote procedure call (@acronym{RPC})
  18435. interface, which allows remote control of the daemon via its Web
  18436. interface, the @command{transmission-remote} command-line client, and
  18437. similar tools.
  18438. Defaults to @samp{#t}.
  18439. @end deftypevr
  18440. @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-bind-address
  18441. The IP address at which to listen for @acronym{RPC} connections, or
  18442. ``0.0.0.0'' to listen at all available IP addresses.
  18443. Defaults to @samp{"0.0.0.0"}.
  18444. @end deftypevr
  18445. @deftypevr {@code{transmission-daemon-configuration} parameter} port-number rpc-port
  18446. The port on which to listen for @acronym{RPC} connections.
  18447. Defaults to @samp{9091}.
  18448. @end deftypevr
  18449. @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-url
  18450. The path prefix to use in the @acronym{RPC}-endpoint @acronym{URL}.
  18451. Defaults to @samp{"/transmission/"}.
  18452. @end deftypevr
  18453. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-authentication-required?
  18454. When @code{#t}, clients must authenticate (see @code{rpc-username} and
  18455. @code{rpc-password}) when using the @acronym{RPC} interface. Note this
  18456. has the side effect of disabling host-name whitelisting (see
  18457. @code{rpc-host-whitelist-enabled?}.
  18458. Defaults to @samp{#f}.
  18459. @end deftypevr
  18460. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string rpc-username
  18461. The username required by clients to access the @acronym{RPC} interface
  18462. when @code{rpc-authentication-required?} is @code{#t}.
  18463. Defaults to @samp{disabled}.
  18464. @end deftypevr
  18465. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-transmission-password-hash rpc-password
  18466. The password required by clients to access the @acronym{RPC} interface
  18467. when @code{rpc-authentication-required?} is @code{#t}. This must be
  18468. specified using a password hash in the format recognized by Transmission
  18469. clients, either copied from an existing @file{settings.json} file or
  18470. generated using the @code{transmission-password-hash} procedure.
  18471. Defaults to @samp{disabled}.
  18472. @end deftypevr
  18473. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-whitelist-enabled?
  18474. When @code{#t}, @acronym{RPC} requests will be accepted only when they
  18475. originate from an address specified in @code{rpc-whitelist}.
  18476. Defaults to @samp{#t}.
  18477. @end deftypevr
  18478. @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-whitelist
  18479. The list of IP and IPv6 addresses from which @acronym{RPC} requests will
  18480. be accepted when @code{rpc-whitelist-enabled?} is @code{#t}. Wildcards
  18481. may be specified using @samp{*}.
  18482. Defaults to @samp{("127.0.0.1" "::1")}.
  18483. @end deftypevr
  18484. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-host-whitelist-enabled?
  18485. When @code{#t}, @acronym{RPC} requests will be accepted only when they
  18486. are addressed to a host named in @code{rpc-host-whitelist}. Note that
  18487. requests to ``localhost'' or ``localhost.'', or to a numeric address,
  18488. are always accepted regardless of these settings.
  18489. Note also this functionality is disabled when
  18490. @code{rpc-authentication-required?} is @code{#t}.
  18491. Defaults to @samp{#t}.
  18492. @end deftypevr
  18493. @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-host-whitelist
  18494. The list of host names recognized by the @acronym{RPC} server when
  18495. @code{rpc-host-whitelist-enabled?} is @code{#t}.
  18496. Defaults to @samp{()}.
  18497. @end deftypevr
  18498. @deftypevr {@code{transmission-daemon-configuration} parameter} message-level message-level
  18499. The minimum severity level of messages to be logged (to
  18500. @file{/var/log/transmission.log}) by the daemon, one of @code{none} (no
  18501. logging), @code{error}, @code{info} and @code{debug}.
  18502. Defaults to @samp{info}.
  18503. @end deftypevr
  18504. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean start-added-torrents?
  18505. When @code{#t}, torrents are started as soon as they are added;
  18506. otherwise, they are added in ``paused'' state.
  18507. Defaults to @samp{#t}.
  18508. @end deftypevr
  18509. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean script-torrent-done-enabled?
  18510. When @code{#t}, the script specified by
  18511. @code{script-torrent-done-filename} will be invoked each time a torrent
  18512. completes.
  18513. Defaults to @samp{#f}.
  18514. @end deftypevr
  18515. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-file-object script-torrent-done-filename
  18516. A file name or file-like object specifying a script to run each time a
  18517. torrent completes, when @code{script-torrent-done-enabled?} is
  18518. @code{#t}.
  18519. Defaults to @samp{disabled}.
  18520. @end deftypevr
  18521. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean scrape-paused-torrents-enabled?
  18522. When @code{#t}, the daemon will scrape trackers for a torrent even when
  18523. the torrent is paused.
  18524. Defaults to @samp{#t}.
  18525. @end deftypevr
  18526. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer cache-size-mb
  18527. The amount of memory, in megabytes, to allocate for the daemon's
  18528. in-memory cache. A larger value may increase performance by reducing
  18529. the frequency of disk I/O.
  18530. Defaults to @samp{4}.
  18531. @end deftypevr
  18532. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean prefetch-enabled?
  18533. When @code{#t}, the daemon will try to improve I/O performance by
  18534. hinting to the operating system which data is likely to be read next
  18535. from disk to satisfy requests from peers.
  18536. Defaults to @samp{#t}.
  18537. @end deftypevr
  18538. @c %end of fragment
  18539. @node Monitoring Services
  18540. @subsection Monitoring Services
  18541. @subsubheading Tailon Service
  18542. @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
  18543. viewing and searching log files.
  18544. The following example will configure the service with default values.
  18545. By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
  18546. @lisp
  18547. (service tailon-service-type)
  18548. @end lisp
  18549. The following example customises more of the Tailon configuration,
  18550. adding @command{sed} to the list of allowed commands.
  18551. @lisp
  18552. (service tailon-service-type
  18553. (tailon-configuration
  18554. (config-file
  18555. (tailon-configuration-file
  18556. (allowed-commands '("tail" "grep" "awk" "sed"))))))
  18557. @end lisp
  18558. @deftp {Data Type} tailon-configuration
  18559. Data type representing the configuration of Tailon.
  18560. This type has the following parameters:
  18561. @table @asis
  18562. @item @code{config-file} (default: @code{(tailon-configuration-file)})
  18563. The configuration file to use for Tailon. This can be set to a
  18564. @dfn{tailon-configuration-file} record value, or any gexp
  18565. (@pxref{G-Expressions}).
  18566. For example, to instead use a local file, the @code{local-file} function
  18567. can be used:
  18568. @lisp
  18569. (service tailon-service-type
  18570. (tailon-configuration
  18571. (config-file (local-file "./my-tailon.conf"))))
  18572. @end lisp
  18573. @item @code{package} (default: @code{tailon})
  18574. The tailon package to use.
  18575. @end table
  18576. @end deftp
  18577. @deftp {Data Type} tailon-configuration-file
  18578. Data type representing the configuration options for Tailon.
  18579. This type has the following parameters:
  18580. @table @asis
  18581. @item @code{files} (default: @code{(list "/var/log")})
  18582. List of files to display. The list can include strings for a single file
  18583. or directory, or a list, where the first item is the name of a
  18584. subsection, and the remaining items are the files or directories in that
  18585. subsection.
  18586. @item @code{bind} (default: @code{"localhost:8080"})
  18587. Address and port to which Tailon should bind on.
  18588. @item @code{relative-root} (default: @code{#f})
  18589. URL path to use for Tailon, set to @code{#f} to not use a path.
  18590. @item @code{allow-transfers?} (default: @code{#t})
  18591. Allow downloading the log files in the web interface.
  18592. @item @code{follow-names?} (default: @code{#t})
  18593. Allow tailing of not-yet existent files.
  18594. @item @code{tail-lines} (default: @code{200})
  18595. Number of lines to read initially from each file.
  18596. @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
  18597. Commands to allow running. By default, @code{sed} is disabled.
  18598. @item @code{debug?} (default: @code{#f})
  18599. Set @code{debug?} to @code{#t} to show debug messages.
  18600. @item @code{wrap-lines} (default: @code{#t})
  18601. Initial line wrapping state in the web interface. Set to @code{#t} to
  18602. initially wrap lines (the default), or to @code{#f} to initially not
  18603. wrap lines.
  18604. @item @code{http-auth} (default: @code{#f})
  18605. HTTP authentication type to use. Set to @code{#f} to disable
  18606. authentication (the default). Supported values are @code{"digest"} or
  18607. @code{"basic"}.
  18608. @item @code{users} (default: @code{#f})
  18609. If HTTP authentication is enabled (see @code{http-auth}), access will be
  18610. restricted to the credentials provided here. To configure users, use a
  18611. list of pairs, where the first element of the pair is the username, and
  18612. the 2nd element of the pair is the password.
  18613. @lisp
  18614. (tailon-configuration-file
  18615. (http-auth "basic")
  18616. (users '(("user1" . "password1")
  18617. ("user2" . "password2"))))
  18618. @end lisp
  18619. @end table
  18620. @end deftp
  18621. @subsubheading Darkstat Service
  18622. @cindex darkstat
  18623. Darkstat is a packet sniffer that captures network traffic, calculates
  18624. statistics about usage, and serves reports over HTTP.
  18625. @defvar {Scheme Variable} darkstat-service-type
  18626. This is the service type for the
  18627. @uref{https://unix4lyfe.org/darkstat/, darkstat}
  18628. service, its value must be a @code{darkstat-configuration} record as in
  18629. this example:
  18630. @lisp
  18631. (service darkstat-service-type
  18632. (darkstat-configuration
  18633. (interface "eno1")))
  18634. @end lisp
  18635. @end defvar
  18636. @deftp {Data Type} darkstat-configuration
  18637. Data type representing the configuration of @command{darkstat}.
  18638. @table @asis
  18639. @item @code{package} (default: @code{darkstat})
  18640. The darkstat package to use.
  18641. @item @code{interface}
  18642. Capture traffic on the specified network interface.
  18643. @item @code{port} (default: @code{"667"})
  18644. Bind the web interface to the specified port.
  18645. @item @code{bind-address} (default: @code{"127.0.0.1"})
  18646. Bind the web interface to the specified address.
  18647. @item @code{base} (default: @code{"/"})
  18648. Specify the path of the base URL@. This can be useful if
  18649. @command{darkstat} is accessed via a reverse proxy.
  18650. @end table
  18651. @end deftp
  18652. @subsubheading Prometheus Node Exporter Service
  18653. @cindex prometheus-node-exporter
  18654. The Prometheus ``node exporter'' makes hardware and operating system statistics
  18655. provided by the Linux kernel available for the Prometheus monitoring system.
  18656. This service should be deployed on all physical nodes and virtual machines,
  18657. where monitoring these statistics is desirable.
  18658. @defvar {Scheme variable} prometheus-node-exporter-service-type
  18659. This is the service type for the
  18660. @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
  18661. service, its value must be a @code{prometheus-node-exporter-configuration}.
  18662. @lisp
  18663. (service prometheus-node-exporter-service-type)
  18664. @end lisp
  18665. @end defvar
  18666. @deftp {Data Type} prometheus-node-exporter-configuration
  18667. Data type representing the configuration of @command{node_exporter}.
  18668. @table @asis
  18669. @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
  18670. The prometheus-node-exporter package to use.
  18671. @item @code{web-listen-address} (default: @code{":9100"})
  18672. Bind the web interface to the specified address.
  18673. @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
  18674. This directory can be used to export metrics specific to this machine.
  18675. Files containing metrics in the text format, with the filename ending in
  18676. @code{.prom} should be placed in this directory.
  18677. @item @code{extra-options} (default: @code{'()})
  18678. Extra options to pass to the Prometheus node exporter.
  18679. @end table
  18680. @end deftp
  18681. @subsubheading Zabbix server
  18682. @cindex zabbix zabbix-server
  18683. Zabbix provides monitoring metrics, among others network utilization, CPU load
  18684. and disk space consumption:
  18685. @itemize
  18686. @item High performance, high capacity (able to monitor hundreds of thousands of devices).
  18687. @item Auto-discovery of servers and network devices and interfaces.
  18688. @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
  18689. @item Distributed monitoring with centralized web administration.
  18690. @item Native high performance agents.
  18691. @item SLA, and ITIL KPI metrics on reporting.
  18692. @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
  18693. @item Remote command execution through Zabbix proxies.
  18694. @end itemize
  18695. @c %start of fragment
  18696. Available @code{zabbix-server-configuration} fields are:
  18697. @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
  18698. The zabbix-server package.
  18699. @end deftypevr
  18700. @deftypevr {@code{zabbix-server-configuration} parameter} string user
  18701. User who will run the Zabbix server.
  18702. Defaults to @samp{"zabbix"}.
  18703. @end deftypevr
  18704. @deftypevr {@code{zabbix-server-configuration} parameter} group group
  18705. Group who will run the Zabbix server.
  18706. Defaults to @samp{"zabbix"}.
  18707. @end deftypevr
  18708. @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
  18709. Database host name.
  18710. Defaults to @samp{"127.0.0.1"}.
  18711. @end deftypevr
  18712. @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
  18713. Database name.
  18714. Defaults to @samp{"zabbix"}.
  18715. @end deftypevr
  18716. @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
  18717. Database user.
  18718. Defaults to @samp{"zabbix"}.
  18719. @end deftypevr
  18720. @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
  18721. Database password. Please, use @code{include-files} with
  18722. @code{DBPassword=SECRET} inside a specified file instead.
  18723. Defaults to @samp{""}.
  18724. @end deftypevr
  18725. @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
  18726. Database port.
  18727. Defaults to @samp{5432}.
  18728. @end deftypevr
  18729. @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
  18730. Specifies where log messages are written to:
  18731. @itemize @bullet
  18732. @item
  18733. @code{system} - syslog.
  18734. @item
  18735. @code{file} - file specified with @code{log-file} parameter.
  18736. @item
  18737. @code{console} - standard output.
  18738. @end itemize
  18739. Defaults to @samp{""}.
  18740. @end deftypevr
  18741. @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
  18742. Log file name for @code{log-type} @code{file} parameter.
  18743. Defaults to @samp{"/var/log/zabbix/server.log"}.
  18744. @end deftypevr
  18745. @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
  18746. Name of PID file.
  18747. Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
  18748. @end deftypevr
  18749. @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
  18750. The location of certificate authority (CA) files for SSL server
  18751. certificate verification.
  18752. Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
  18753. @end deftypevr
  18754. @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
  18755. Location of SSL client certificates.
  18756. Defaults to @samp{"/etc/ssl/certs"}.
  18757. @end deftypevr
  18758. @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
  18759. Extra options will be appended to Zabbix server configuration file.
  18760. Defaults to @samp{""}.
  18761. @end deftypevr
  18762. @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
  18763. You may include individual files or all files in a directory in the
  18764. configuration file.
  18765. Defaults to @samp{()}.
  18766. @end deftypevr
  18767. @c %end of fragment
  18768. @subsubheading Zabbix agent
  18769. @cindex zabbix zabbix-agent
  18770. Zabbix agent gathers information for Zabbix server.
  18771. @c %start of fragment
  18772. Available @code{zabbix-agent-configuration} fields are:
  18773. @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
  18774. The zabbix-agent package.
  18775. @end deftypevr
  18776. @deftypevr {@code{zabbix-agent-configuration} parameter} string user
  18777. User who will run the Zabbix agent.
  18778. Defaults to @samp{"zabbix"}.
  18779. @end deftypevr
  18780. @deftypevr {@code{zabbix-agent-configuration} parameter} group group
  18781. Group who will run the Zabbix agent.
  18782. Defaults to @samp{"zabbix"}.
  18783. @end deftypevr
  18784. @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
  18785. Unique, case sensitive hostname which is required for active checks and
  18786. must match hostname as configured on the server.
  18787. Defaults to @samp{""}.
  18788. @end deftypevr
  18789. @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
  18790. Specifies where log messages are written to:
  18791. @itemize @bullet
  18792. @item
  18793. @code{system} - syslog.
  18794. @item
  18795. @code{file} - file specified with @code{log-file} parameter.
  18796. @item
  18797. @code{console} - standard output.
  18798. @end itemize
  18799. Defaults to @samp{""}.
  18800. @end deftypevr
  18801. @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
  18802. Log file name for @code{log-type} @code{file} parameter.
  18803. Defaults to @samp{"/var/log/zabbix/agent.log"}.
  18804. @end deftypevr
  18805. @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
  18806. Name of PID file.
  18807. Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
  18808. @end deftypevr
  18809. @deftypevr {@code{zabbix-agent-configuration} parameter} list server
  18810. List of IP addresses, optionally in CIDR notation, or hostnames of
  18811. Zabbix servers and Zabbix proxies. Incoming connections will be
  18812. accepted only from the hosts listed here.
  18813. Defaults to @samp{("127.0.0.1")}.
  18814. @end deftypevr
  18815. @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
  18816. List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
  18817. proxies for active checks. If port is not specified, default port is
  18818. used. If this parameter is not specified, active checks are disabled.
  18819. Defaults to @samp{("127.0.0.1")}.
  18820. @end deftypevr
  18821. @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
  18822. Extra options will be appended to Zabbix server configuration file.
  18823. Defaults to @samp{""}.
  18824. @end deftypevr
  18825. @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
  18826. You may include individual files or all files in a directory in the
  18827. configuration file.
  18828. Defaults to @samp{()}.
  18829. @end deftypevr
  18830. @c %end of fragment
  18831. @subsubheading Zabbix front-end
  18832. @cindex zabbix zabbix-front-end
  18833. This service provides a WEB interface to Zabbix server.
  18834. @c %start of fragment
  18835. Available @code{zabbix-front-end-configuration} fields are:
  18836. @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
  18837. NGINX configuration.
  18838. @end deftypevr
  18839. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
  18840. Database host name.
  18841. Defaults to @samp{"localhost"}.
  18842. @end deftypevr
  18843. @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
  18844. Database port.
  18845. Defaults to @samp{5432}.
  18846. @end deftypevr
  18847. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
  18848. Database name.
  18849. Defaults to @samp{"zabbix"}.
  18850. @end deftypevr
  18851. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
  18852. Database user.
  18853. Defaults to @samp{"zabbix"}.
  18854. @end deftypevr
  18855. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
  18856. Database password. Please, use @code{db-secret-file} instead.
  18857. Defaults to @samp{""}.
  18858. @end deftypevr
  18859. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
  18860. Secret file containing the credentials for the Zabbix front-end. The value
  18861. must be a local file name, not a G-expression. You are expected to create
  18862. this file manually. Its contents will be copied into @file{zabbix.conf.php}
  18863. as the value of @code{$DB['PASSWORD']}.
  18864. Defaults to @samp{""}.
  18865. @end deftypevr
  18866. @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
  18867. Zabbix server hostname.
  18868. Defaults to @samp{"localhost"}.
  18869. @end deftypevr
  18870. @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
  18871. Zabbix server port.
  18872. Defaults to @samp{10051}.
  18873. @end deftypevr
  18874. @c %end of fragment
  18875. @node Kerberos Services
  18876. @subsection Kerberos Services
  18877. @cindex Kerberos
  18878. The @code{(gnu services kerberos)} module provides services relating to
  18879. the authentication protocol @dfn{Kerberos}.
  18880. @subsubheading Krb5 Service
  18881. Programs using a Kerberos client library normally
  18882. expect a configuration file in @file{/etc/krb5.conf}.
  18883. This service generates such a file from a definition provided in the
  18884. operating system declaration.
  18885. It does not cause any daemon to be started.
  18886. No ``keytab'' files are provided by this service---you must explicitly create them.
  18887. This service is known to work with the MIT client library, @code{mit-krb5}.
  18888. Other implementations have not been tested.
  18889. @defvr {Scheme Variable} krb5-service-type
  18890. A service type for Kerberos 5 clients.
  18891. @end defvr
  18892. @noindent
  18893. Here is an example of its use:
  18894. @lisp
  18895. (service krb5-service-type
  18896. (krb5-configuration
  18897. (default-realm "EXAMPLE.COM")
  18898. (allow-weak-crypto? #t)
  18899. (realms (list
  18900. (krb5-realm
  18901. (name "EXAMPLE.COM")
  18902. (admin-server "groucho.example.com")
  18903. (kdc "karl.example.com"))
  18904. (krb5-realm
  18905. (name "ARGRX.EDU")
  18906. (admin-server "kerb-admin.argrx.edu")
  18907. (kdc "keys.argrx.edu"))))))
  18908. @end lisp
  18909. @noindent
  18910. This example provides a Kerberos@tie{}5 client configuration which:
  18911. @itemize
  18912. @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
  18913. of which have distinct administration servers and key distribution centers;
  18914. @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
  18915. specified by clients;
  18916. @item Accepts services which only support encryption types known to be weak.
  18917. @end itemize
  18918. The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
  18919. Only the most commonly used ones are described here.
  18920. For a full list, and more detailed explanation of each, see the MIT
  18921. @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
  18922. documentation.
  18923. @deftp {Data Type} krb5-realm
  18924. @cindex realm, kerberos
  18925. @table @asis
  18926. @item @code{name}
  18927. This field is a string identifying the name of the realm.
  18928. A common convention is to use the fully qualified DNS name of your organization,
  18929. converted to upper case.
  18930. @item @code{admin-server}
  18931. This field is a string identifying the host where the administration server is
  18932. running.
  18933. @item @code{kdc}
  18934. This field is a string identifying the key distribution center
  18935. for the realm.
  18936. @end table
  18937. @end deftp
  18938. @deftp {Data Type} krb5-configuration
  18939. @table @asis
  18940. @item @code{allow-weak-crypto?} (default: @code{#f})
  18941. If this flag is @code{#t} then services which only offer encryption algorithms
  18942. known to be weak will be accepted.
  18943. @item @code{default-realm} (default: @code{#f})
  18944. This field should be a string identifying the default Kerberos
  18945. realm for the client.
  18946. You should set this field to the name of your Kerberos realm.
  18947. If this value is @code{#f}
  18948. then a realm must be specified with every Kerberos principal when invoking programs
  18949. such as @command{kinit}.
  18950. @item @code{realms}
  18951. This should be a non-empty list of @code{krb5-realm} objects, which clients may
  18952. access.
  18953. Normally, one of them will have a @code{name} field matching the @code{default-realm}
  18954. field.
  18955. @end table
  18956. @end deftp
  18957. @subsubheading PAM krb5 Service
  18958. @cindex pam-krb5
  18959. The @code{pam-krb5} service allows for login authentication and password
  18960. management via Kerberos.
  18961. You will need this service if you want PAM enabled applications to authenticate
  18962. users using Kerberos.
  18963. @defvr {Scheme Variable} pam-krb5-service-type
  18964. A service type for the Kerberos 5 PAM module.
  18965. @end defvr
  18966. @deftp {Data Type} pam-krb5-configuration
  18967. Data type representing the configuration of the Kerberos 5 PAM module.
  18968. This type has the following parameters:
  18969. @table @asis
  18970. @item @code{pam-krb5} (default: @code{pam-krb5})
  18971. The pam-krb5 package to use.
  18972. @item @code{minimum-uid} (default: @code{1000})
  18973. The smallest user ID for which Kerberos authentications should be attempted.
  18974. Local accounts with lower values will silently fail to authenticate.
  18975. @end table
  18976. @end deftp
  18977. @node LDAP Services
  18978. @subsection LDAP Services
  18979. @cindex LDAP
  18980. @cindex nslcd, LDAP service
  18981. The @code{(gnu services authentication)} module provides the
  18982. @code{nslcd-service-type}, which can be used to authenticate against an LDAP
  18983. server. In addition to configuring the service itself, you may want to add
  18984. @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
  18985. Switch} for detailed information.
  18986. Here is a simple operating system declaration with a default configuration of
  18987. the @code{nslcd-service-type} and a Name Service Switch configuration that
  18988. consults the @code{ldap} name service last:
  18989. @lisp
  18990. (use-service-modules authentication)
  18991. (use-modules (gnu system nss))
  18992. ...
  18993. (operating-system
  18994. ...
  18995. (services
  18996. (cons*
  18997. (service nslcd-service-type)
  18998. (service dhcp-client-service-type)
  18999. %base-services))
  19000. (name-service-switch
  19001. (let ((services (list (name-service (name "db"))
  19002. (name-service (name "files"))
  19003. (name-service (name "ldap")))))
  19004. (name-service-switch
  19005. (inherit %mdns-host-lookup-nss)
  19006. (password services)
  19007. (shadow services)
  19008. (group services)
  19009. (netgroup services)
  19010. (gshadow services)))))
  19011. @end lisp
  19012. @c %start of generated documentation for nslcd-configuration
  19013. Available @code{nslcd-configuration} fields are:
  19014. @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
  19015. The @code{nss-pam-ldapd} package to use.
  19016. @end deftypevr
  19017. @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
  19018. The number of threads to start that can handle requests and perform LDAP
  19019. queries. Each thread opens a separate connection to the LDAP server.
  19020. The default is to start 5 threads.
  19021. Defaults to @samp{disabled}.
  19022. @end deftypevr
  19023. @deftypevr {@code{nslcd-configuration} parameter} string uid
  19024. This specifies the user id with which the daemon should be run.
  19025. Defaults to @samp{"nslcd"}.
  19026. @end deftypevr
  19027. @deftypevr {@code{nslcd-configuration} parameter} string gid
  19028. This specifies the group id with which the daemon should be run.
  19029. Defaults to @samp{"nslcd"}.
  19030. @end deftypevr
  19031. @deftypevr {@code{nslcd-configuration} parameter} log-option log
  19032. This option controls the way logging is done via a list containing
  19033. SCHEME and LEVEL@. The SCHEME argument may either be the symbols
  19034. @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
  19035. argument is optional and specifies the log level. The log level may be
  19036. one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
  19037. @samp{notice}, @samp{info} or @samp{debug}. All messages with the
  19038. specified log level or higher are logged.
  19039. Defaults to @samp{("/var/log/nslcd" info)}.
  19040. @end deftypevr
  19041. @deftypevr {@code{nslcd-configuration} parameter} list uri
  19042. The list of LDAP server URIs. Normally, only the first server will be
  19043. used with the following servers as fall-back.
  19044. Defaults to @samp{("ldap://localhost:389/")}.
  19045. @end deftypevr
  19046. @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
  19047. The version of the LDAP protocol to use. The default is to use the
  19048. maximum version supported by the LDAP library.
  19049. Defaults to @samp{disabled}.
  19050. @end deftypevr
  19051. @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
  19052. Specifies the distinguished name with which to bind to the directory
  19053. server for lookups. The default is to bind anonymously.
  19054. Defaults to @samp{disabled}.
  19055. @end deftypevr
  19056. @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
  19057. Specifies the credentials with which to bind. This option is only
  19058. applicable when used with binddn.
  19059. Defaults to @samp{disabled}.
  19060. @end deftypevr
  19061. @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
  19062. Specifies the distinguished name to use when the root user tries to
  19063. modify a user's password using the PAM module.
  19064. Defaults to @samp{disabled}.
  19065. @end deftypevr
  19066. @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
  19067. Specifies the credentials with which to bind if the root user tries to
  19068. change a user's password. This option is only applicable when used with
  19069. rootpwmoddn
  19070. Defaults to @samp{disabled}.
  19071. @end deftypevr
  19072. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
  19073. Specifies the SASL mechanism to be used when performing SASL
  19074. authentication.
  19075. Defaults to @samp{disabled}.
  19076. @end deftypevr
  19077. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
  19078. Specifies the SASL realm to be used when performing SASL authentication.
  19079. Defaults to @samp{disabled}.
  19080. @end deftypevr
  19081. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
  19082. Specifies the authentication identity to be used when performing SASL
  19083. authentication.
  19084. Defaults to @samp{disabled}.
  19085. @end deftypevr
  19086. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
  19087. Specifies the authorization identity to be used when performing SASL
  19088. authentication.
  19089. Defaults to @samp{disabled}.
  19090. @end deftypevr
  19091. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
  19092. Determines whether the LDAP server host name should be canonicalised. If
  19093. this is enabled the LDAP library will do a reverse host name lookup. By
  19094. default, it is left up to the LDAP library whether this check is
  19095. performed or not.
  19096. Defaults to @samp{disabled}.
  19097. @end deftypevr
  19098. @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
  19099. Set the name for the GSS-API Kerberos credentials cache.
  19100. Defaults to @samp{disabled}.
  19101. @end deftypevr
  19102. @deftypevr {@code{nslcd-configuration} parameter} string base
  19103. The directory search base.
  19104. Defaults to @samp{"dc=example,dc=com"}.
  19105. @end deftypevr
  19106. @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
  19107. Specifies the search scope (subtree, onelevel, base or children). The
  19108. default scope is subtree; base scope is almost never useful for name
  19109. service lookups; children scope is not supported on all servers.
  19110. Defaults to @samp{(subtree)}.
  19111. @end deftypevr
  19112. @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
  19113. Specifies the policy for dereferencing aliases. The default policy is
  19114. to never dereference aliases.
  19115. Defaults to @samp{disabled}.
  19116. @end deftypevr
  19117. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
  19118. Specifies whether automatic referral chasing should be enabled. The
  19119. default behaviour is to chase referrals.
  19120. Defaults to @samp{disabled}.
  19121. @end deftypevr
  19122. @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
  19123. This option allows for custom attributes to be looked up instead of the
  19124. default RFC 2307 attributes. It is a list of maps, each consisting of
  19125. the name of a map, the RFC 2307 attribute to match and the query
  19126. expression for the attribute as it is available in the directory.
  19127. Defaults to @samp{()}.
  19128. @end deftypevr
  19129. @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
  19130. A list of filters consisting of the name of a map to which the filter
  19131. applies and an LDAP search filter expression.
  19132. Defaults to @samp{()}.
  19133. @end deftypevr
  19134. @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
  19135. Specifies the time limit in seconds to use when connecting to the
  19136. directory server. The default value is 10 seconds.
  19137. Defaults to @samp{disabled}.
  19138. @end deftypevr
  19139. @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
  19140. Specifies the time limit (in seconds) to wait for a response from the
  19141. LDAP server. A value of zero, which is the default, is to wait
  19142. indefinitely for searches to be completed.
  19143. Defaults to @samp{disabled}.
  19144. @end deftypevr
  19145. @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
  19146. Specifies the period if inactivity (in seconds) after which the con‐
  19147. nection to the LDAP server will be closed. The default is not to time
  19148. out connections.
  19149. Defaults to @samp{disabled}.
  19150. @end deftypevr
  19151. @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
  19152. Specifies the number of seconds to sleep when connecting to all LDAP
  19153. servers fails. By default one second is waited between the first
  19154. failure and the first retry.
  19155. Defaults to @samp{disabled}.
  19156. @end deftypevr
  19157. @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
  19158. Specifies the time after which the LDAP server is considered to be
  19159. permanently unavailable. Once this time is reached retries will be done
  19160. only once per this time period. The default value is 10 seconds.
  19161. Defaults to @samp{disabled}.
  19162. @end deftypevr
  19163. @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
  19164. Specifies whether to use SSL/TLS or not (the default is not to). If
  19165. 'start-tls is specified then StartTLS is used rather than raw LDAP over
  19166. SSL.
  19167. Defaults to @samp{disabled}.
  19168. @end deftypevr
  19169. @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
  19170. Specifies what checks to perform on a server-supplied certificate. The
  19171. meaning of the values is described in the ldap.conf(5) manual page.
  19172. Defaults to @samp{disabled}.
  19173. @end deftypevr
  19174. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
  19175. Specifies the directory containing X.509 certificates for peer authen‐
  19176. tication. This parameter is ignored when using GnuTLS.
  19177. Defaults to @samp{disabled}.
  19178. @end deftypevr
  19179. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
  19180. Specifies the path to the X.509 certificate for peer authentication.
  19181. Defaults to @samp{disabled}.
  19182. @end deftypevr
  19183. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
  19184. Specifies the path to an entropy source. This parameter is ignored when
  19185. using GnuTLS.
  19186. Defaults to @samp{disabled}.
  19187. @end deftypevr
  19188. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
  19189. Specifies the ciphers to use for TLS as a string.
  19190. Defaults to @samp{disabled}.
  19191. @end deftypevr
  19192. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
  19193. Specifies the path to the file containing the local certificate for
  19194. client TLS authentication.
  19195. Defaults to @samp{disabled}.
  19196. @end deftypevr
  19197. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
  19198. Specifies the path to the file containing the private key for client TLS
  19199. authentication.
  19200. Defaults to @samp{disabled}.
  19201. @end deftypevr
  19202. @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
  19203. Set this to a number greater than 0 to request paged results from the
  19204. LDAP server in accordance with RFC2696. The default (0) is to not
  19205. request paged results.
  19206. Defaults to @samp{disabled}.
  19207. @end deftypevr
  19208. @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
  19209. This option prevents group membership lookups through LDAP for the
  19210. specified users. Alternatively, the value 'all-local may be used. With
  19211. that value nslcd builds a full list of non-LDAP users on startup.
  19212. Defaults to @samp{disabled}.
  19213. @end deftypevr
  19214. @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
  19215. This option ensures that LDAP users with a numeric user id lower than
  19216. the specified value are ignored.
  19217. Defaults to @samp{disabled}.
  19218. @end deftypevr
  19219. @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
  19220. This option specifies an offset that is added to all LDAP numeric user
  19221. ids. This can be used to avoid user id collisions with local users.
  19222. Defaults to @samp{disabled}.
  19223. @end deftypevr
  19224. @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
  19225. This option specifies an offset that is added to all LDAP numeric group
  19226. ids. This can be used to avoid user id collisions with local groups.
  19227. Defaults to @samp{disabled}.
  19228. @end deftypevr
  19229. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
  19230. If this option is set, the member attribute of a group may point to
  19231. another group. Members of nested groups are also returned in the higher
  19232. level group and parent groups are returned when finding groups for a
  19233. specific user. The default is not to perform extra searches for nested
  19234. groups.
  19235. Defaults to @samp{disabled}.
  19236. @end deftypevr
  19237. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
  19238. If this option is set, the group member list is not retrieved when
  19239. looking up groups. Lookups for finding which groups a user belongs to
  19240. will remain functional so the user will likely still get the correct
  19241. groups assigned on login.
  19242. Defaults to @samp{disabled}.
  19243. @end deftypevr
  19244. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
  19245. If this option is set, functions which cause all user/group entries to
  19246. be loaded from the directory will not succeed in doing so. This can
  19247. dramatically reduce LDAP server load in situations where there are a
  19248. great number of users and/or groups. This option is not recommended for
  19249. most configurations.
  19250. Defaults to @samp{disabled}.
  19251. @end deftypevr
  19252. @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
  19253. This option can be used to specify how user and group names are verified
  19254. within the system. This pattern is used to check all user and group
  19255. names that are requested and returned from LDAP.
  19256. Defaults to @samp{disabled}.
  19257. @end deftypevr
  19258. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
  19259. This specifies whether or not to perform searches using case-insensitive
  19260. matching. Enabling this could open up the system to authorization
  19261. bypass vulnerabilities and introduce nscd cache poisoning
  19262. vulnerabilities which allow denial of service.
  19263. Defaults to @samp{disabled}.
  19264. @end deftypevr
  19265. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
  19266. This option specifies whether password policy controls are requested and
  19267. handled from the LDAP server when performing user authentication.
  19268. Defaults to @samp{disabled}.
  19269. @end deftypevr
  19270. @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
  19271. By default nslcd performs an LDAP search with the user's credentials
  19272. after BIND (authentication) to ensure that the BIND operation was
  19273. successful. The default search is a simple check to see if the user's
  19274. DN exists. A search filter can be specified that will be used instead.
  19275. It should return at least one entry.
  19276. Defaults to @samp{disabled}.
  19277. @end deftypevr
  19278. @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
  19279. This option allows flexible fine tuning of the authorisation check that
  19280. should be performed. The search filter specified is executed and if any
  19281. entries match, access is granted, otherwise access is denied.
  19282. Defaults to @samp{disabled}.
  19283. @end deftypevr
  19284. @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
  19285. If this option is set password modification using pam_ldap will be
  19286. denied and the specified message will be presented to the user instead.
  19287. The message can be used to direct the user to an alternative means of
  19288. changing their password.
  19289. Defaults to @samp{disabled}.
  19290. @end deftypevr
  19291. @deftypevr {@code{nslcd-configuration} parameter} list pam-services
  19292. List of pam service names for which LDAP authentication should suffice.
  19293. Defaults to @samp{()}.
  19294. @end deftypevr
  19295. @c %end of generated documentation for nslcd-configuration
  19296. @node Web Services
  19297. @subsection Web Services
  19298. @cindex web
  19299. @cindex www
  19300. @cindex HTTP
  19301. The @code{(gnu services web)} module provides the Apache HTTP Server,
  19302. the nginx web server, and also a fastcgi wrapper daemon.
  19303. @subsubheading Apache HTTP Server
  19304. @deffn {Scheme Variable} httpd-service-type
  19305. Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
  19306. (@dfn{httpd}). The value for this service type is a
  19307. @code{httpd-configuration} record.
  19308. A simple example configuration is given below.
  19309. @lisp
  19310. (service httpd-service-type
  19311. (httpd-configuration
  19312. (config
  19313. (httpd-config-file
  19314. (server-name "www.example.com")
  19315. (document-root "/srv/http/www.example.com")))))
  19316. @end lisp
  19317. Other services can also extend the @code{httpd-service-type} to add to
  19318. the configuration.
  19319. @lisp
  19320. (simple-service 'www.example.com-server httpd-service-type
  19321. (list
  19322. (httpd-virtualhost
  19323. "*:80"
  19324. (list (string-join '("ServerName www.example.com"
  19325. "DocumentRoot /srv/http/www.example.com")
  19326. "\n")))))
  19327. @end lisp
  19328. @end deffn
  19329. The details for the @code{httpd-configuration}, @code{httpd-module},
  19330. @code{httpd-config-file} and @code{httpd-virtualhost} record types are
  19331. given below.
  19332. @deffn {Data Type} httpd-configuration
  19333. This data type represents the configuration for the httpd service.
  19334. @table @asis
  19335. @item @code{package} (default: @code{httpd})
  19336. The httpd package to use.
  19337. @item @code{pid-file} (default: @code{"/var/run/httpd"})
  19338. The pid file used by the shepherd-service.
  19339. @item @code{config} (default: @code{(httpd-config-file)})
  19340. The configuration file to use with the httpd service. The default value
  19341. is a @code{httpd-config-file} record, but this can also be a different
  19342. G-expression that generates a file, for example a @code{plain-file}. A
  19343. file outside of the store can also be specified through a string.
  19344. @end table
  19345. @end deffn
  19346. @deffn {Data Type} httpd-module
  19347. This data type represents a module for the httpd service.
  19348. @table @asis
  19349. @item @code{name}
  19350. The name of the module.
  19351. @item @code{file}
  19352. The file for the module. This can be relative to the httpd package being
  19353. used, the absolute location of a file, or a G-expression for a file
  19354. within the store, for example @code{(file-append mod-wsgi
  19355. "/modules/mod_wsgi.so")}.
  19356. @end table
  19357. @end deffn
  19358. @defvr {Scheme Variable} %default-httpd-modules
  19359. A default list of @code{httpd-module} objects.
  19360. @end defvr
  19361. @deffn {Data Type} httpd-config-file
  19362. This data type represents a configuration file for the httpd service.
  19363. @table @asis
  19364. @item @code{modules} (default: @code{%default-httpd-modules})
  19365. The modules to load. Additional modules can be added here, or loaded by
  19366. additional configuration.
  19367. For example, in order to handle requests for PHP files, you can use Apache’s
  19368. @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
  19369. @lisp
  19370. (service httpd-service-type
  19371. (httpd-configuration
  19372. (config
  19373. (httpd-config-file
  19374. (modules (cons*
  19375. (httpd-module
  19376. (name "proxy_module")
  19377. (file "modules/mod_proxy.so"))
  19378. (httpd-module
  19379. (name "proxy_fcgi_module")
  19380. (file "modules/mod_proxy_fcgi.so"))
  19381. %default-httpd-modules))
  19382. (extra-config (list "\
  19383. <FilesMatch \\.php$>
  19384. SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
  19385. </FilesMatch>"))))))
  19386. (service php-fpm-service-type
  19387. (php-fpm-configuration
  19388. (socket "/var/run/php-fpm.sock")
  19389. (socket-group "httpd")))
  19390. @end lisp
  19391. @item @code{server-root} (default: @code{httpd})
  19392. The @code{ServerRoot} in the configuration file, defaults to the httpd
  19393. package. Directives including @code{Include} and @code{LoadModule} are
  19394. taken as relative to the server root.
  19395. @item @code{server-name} (default: @code{#f})
  19396. The @code{ServerName} in the configuration file, used to specify the
  19397. request scheme, hostname and port that the server uses to identify
  19398. itself.
  19399. This doesn't need to be set in the server config, and can be specified
  19400. in virtual hosts. The default is @code{#f} to not specify a
  19401. @code{ServerName}.
  19402. @item @code{document-root} (default: @code{"/srv/http"})
  19403. The @code{DocumentRoot} from which files will be served.
  19404. @item @code{listen} (default: @code{'("80")})
  19405. The list of values for the @code{Listen} directives in the config
  19406. file. The value should be a list of strings, when each string can
  19407. specify the port number to listen on, and optionally the IP address and
  19408. protocol to use.
  19409. @item @code{pid-file} (default: @code{"/var/run/httpd"})
  19410. The @code{PidFile} to use. This should match the @code{pid-file} set in
  19411. the @code{httpd-configuration} so that the Shepherd service is
  19412. configured correctly.
  19413. @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
  19414. The @code{ErrorLog} to which the server will log errors.
  19415. @item @code{user} (default: @code{"httpd"})
  19416. The @code{User} which the server will answer requests as.
  19417. @item @code{group} (default: @code{"httpd"})
  19418. The @code{Group} which the server will answer requests as.
  19419. @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
  19420. A flat list of strings and G-expressions which will be added to the end
  19421. of the configuration file.
  19422. Any values which the service is extended with will be appended to this
  19423. list.
  19424. @end table
  19425. @end deffn
  19426. @deffn {Data Type} httpd-virtualhost
  19427. This data type represents a virtualhost configuration block for the httpd service.
  19428. These should be added to the extra-config for the httpd-service.
  19429. @lisp
  19430. (simple-service 'www.example.com-server httpd-service-type
  19431. (list
  19432. (httpd-virtualhost
  19433. "*:80"
  19434. (list (string-join '("ServerName www.example.com"
  19435. "DocumentRoot /srv/http/www.example.com")
  19436. "\n")))))
  19437. @end lisp
  19438. @table @asis
  19439. @item @code{addresses-and-ports}
  19440. The addresses and ports for the @code{VirtualHost} directive.
  19441. @item @code{contents}
  19442. The contents of the @code{VirtualHost} directive, this should be a list
  19443. of strings and G-expressions.
  19444. @end table
  19445. @end deffn
  19446. @subsubheading NGINX
  19447. @deffn {Scheme Variable} nginx-service-type
  19448. Service type for the @uref{https://nginx.org/,NGinx} web server. The
  19449. value for this service type is a @code{<nginx-configuration>} record.
  19450. A simple example configuration is given below.
  19451. @lisp
  19452. (service nginx-service-type
  19453. (nginx-configuration
  19454. (server-blocks
  19455. (list (nginx-server-configuration
  19456. (server-name '("www.example.com"))
  19457. (root "/srv/http/www.example.com"))))))
  19458. @end lisp
  19459. In addition to adding server blocks to the service configuration
  19460. directly, this service can be extended by other services to add server
  19461. blocks, as in this example:
  19462. @lisp
  19463. (simple-service 'my-extra-server nginx-service-type
  19464. (list (nginx-server-configuration
  19465. (root "/srv/http/extra-website")
  19466. (try-files (list "$uri" "$uri/index.html")))))
  19467. @end lisp
  19468. @end deffn
  19469. At startup, @command{nginx} has not yet read its configuration file, so
  19470. it uses a default file to log error messages. If it fails to load its
  19471. configuration file, that is where error messages are logged. After the
  19472. configuration file is loaded, the default error log file changes as per
  19473. configuration. In our case, startup error messages can be found in
  19474. @file{/var/run/nginx/logs/error.log}, and after configuration in
  19475. @file{/var/log/nginx/error.log}. The second location can be changed
  19476. with the @var{log-directory} configuration option.
  19477. @deffn {Data Type} nginx-configuration
  19478. This data type represents the configuration for NGinx. Some
  19479. configuration can be done through this and the other provided record
  19480. types, or alternatively, a config file can be provided.
  19481. @table @asis
  19482. @item @code{nginx} (default: @code{nginx})
  19483. The nginx package to use.
  19484. @item @code{log-directory} (default: @code{"/var/log/nginx"})
  19485. The directory to which NGinx will write log files.
  19486. @item @code{run-directory} (default: @code{"/var/run/nginx"})
  19487. The directory in which NGinx will create a pid file, and write temporary
  19488. files.
  19489. @item @code{server-blocks} (default: @code{'()})
  19490. A list of @dfn{server blocks} to create in the generated configuration
  19491. file, the elements should be of type
  19492. @code{<nginx-server-configuration>}.
  19493. The following example would setup NGinx to serve @code{www.example.com}
  19494. from the @code{/srv/http/www.example.com} directory, without using
  19495. HTTPS.
  19496. @lisp
  19497. (service nginx-service-type
  19498. (nginx-configuration
  19499. (server-blocks
  19500. (list (nginx-server-configuration
  19501. (server-name '("www.example.com"))
  19502. (root "/srv/http/www.example.com"))))))
  19503. @end lisp
  19504. @item @code{upstream-blocks} (default: @code{'()})
  19505. A list of @dfn{upstream blocks} to create in the generated configuration
  19506. file, the elements should be of type
  19507. @code{<nginx-upstream-configuration>}.
  19508. Configuring upstreams through the @code{upstream-blocks} can be useful
  19509. when combined with @code{locations} in the
  19510. @code{<nginx-server-configuration>} records. The following example
  19511. creates a server configuration with one location configuration, that
  19512. will proxy requests to a upstream configuration, which will handle
  19513. requests with two servers.
  19514. @lisp
  19515. (service
  19516. nginx-service-type
  19517. (nginx-configuration
  19518. (server-blocks
  19519. (list (nginx-server-configuration
  19520. (server-name '("www.example.com"))
  19521. (root "/srv/http/www.example.com")
  19522. (locations
  19523. (list
  19524. (nginx-location-configuration
  19525. (uri "/path1")
  19526. (body '("proxy_pass http://server-proxy;"))))))))
  19527. (upstream-blocks
  19528. (list (nginx-upstream-configuration
  19529. (name "server-proxy")
  19530. (servers (list "server1.example.com"
  19531. "server2.example.com")))))))
  19532. @end lisp
  19533. @item @code{file} (default: @code{#f})
  19534. If a configuration @var{file} is provided, this will be used, rather than
  19535. generating a configuration file from the provided @code{log-directory},
  19536. @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
  19537. proper operation, these arguments should match what is in @var{file} to ensure
  19538. that the directories are created when the service is activated.
  19539. This can be useful if you have an existing configuration file, or it's
  19540. not possible to do what is required through the other parts of the
  19541. nginx-configuration record.
  19542. @item @code{server-names-hash-bucket-size} (default: @code{#f})
  19543. Bucket size for the server names hash tables, defaults to @code{#f} to
  19544. use the size of the processors cache line.
  19545. @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
  19546. Maximum bucket size for the server names hash tables.
  19547. @item @code{modules} (default: @code{'()})
  19548. List of nginx dynamic modules to load. This should be a list of file
  19549. names of loadable modules, as in this example:
  19550. @lisp
  19551. (modules
  19552. (list
  19553. (file-append nginx-accept-language-module "\
  19554. /etc/nginx/modules/ngx_http_accept_language_module.so")
  19555. (file-append nginx-lua-module "\
  19556. /etc/nginx/modules/ngx_http_lua_module.so")))
  19557. @end lisp
  19558. @item @code{lua-package-path} (default: @code{'()})
  19559. List of nginx lua packages to load. This should be a list of package
  19560. names of loadable lua modules, as in this example:
  19561. @lisp
  19562. (lua-package-path (list lua-resty-core
  19563. lua-resty-lrucache
  19564. lua-resty-signal
  19565. lua-tablepool
  19566. lua-resty-shell))
  19567. @end lisp
  19568. @item @code{lua-package-cpath} (default: @code{'()})
  19569. List of nginx lua C packages to load. This should be a list of package
  19570. names of loadable lua C modules, as in this example:
  19571. @lisp
  19572. (lua-package-cpath (list lua-resty-signal))
  19573. @end lisp
  19574. @item @code{global-directives} (default: @code{'((events . ()))})
  19575. Association list of global directives for the top level of the nginx
  19576. configuration. Values may themselves be association lists.
  19577. @lisp
  19578. (global-directives
  19579. `((worker_processes . 16)
  19580. (pcre_jit . on)
  19581. (events . ((worker_connections . 1024)))))
  19582. @end lisp
  19583. @item @code{extra-content} (default: @code{""})
  19584. Extra content for the @code{http} block. Should be string or a string
  19585. valued G-expression.
  19586. @end table
  19587. @end deffn
  19588. @deftp {Data Type} nginx-server-configuration
  19589. Data type representing the configuration of an nginx server block.
  19590. This type has the following parameters:
  19591. @table @asis
  19592. @item @code{listen} (default: @code{'("80" "443 ssl")})
  19593. Each @code{listen} directive sets the address and port for IP, or the
  19594. path for a UNIX-domain socket on which the server will accept requests.
  19595. Both address and port, or only address or only port can be specified.
  19596. An address may also be a hostname, for example:
  19597. @lisp
  19598. '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
  19599. @end lisp
  19600. @item @code{server-name} (default: @code{(list 'default)})
  19601. A list of server names this server represents. @code{'default} represents the
  19602. default server for connections matching no other server.
  19603. @item @code{root} (default: @code{"/srv/http"})
  19604. Root of the website nginx will serve.
  19605. @item @code{locations} (default: @code{'()})
  19606. A list of @dfn{nginx-location-configuration} or
  19607. @dfn{nginx-named-location-configuration} records to use within this
  19608. server block.
  19609. @item @code{index} (default: @code{(list "index.html")})
  19610. Index files to look for when clients ask for a directory. If it cannot be found,
  19611. Nginx will send the list of files in the directory.
  19612. @item @code{try-files} (default: @code{'()})
  19613. A list of files whose existence is checked in the specified order.
  19614. @code{nginx} will use the first file it finds to process the request.
  19615. @item @code{ssl-certificate} (default: @code{#f})
  19616. Where to find the certificate for secure connections. Set it to @code{#f} if
  19617. you don't have a certificate or you don't want to use HTTPS.
  19618. @item @code{ssl-certificate-key} (default: @code{#f})
  19619. Where to find the private key for secure connections. Set it to @code{#f} if
  19620. you don't have a key or you don't want to use HTTPS.
  19621. @item @code{server-tokens?} (default: @code{#f})
  19622. Whether the server should add its configuration to response.
  19623. @item @code{raw-content} (default: @code{'()})
  19624. A list of raw lines added to the server block.
  19625. @end table
  19626. @end deftp
  19627. @deftp {Data Type} nginx-upstream-configuration
  19628. Data type representing the configuration of an nginx @code{upstream}
  19629. block. This type has the following parameters:
  19630. @table @asis
  19631. @item @code{name}
  19632. Name for this group of servers.
  19633. @item @code{servers}
  19634. Specify the addresses of the servers in the group. The address can be
  19635. specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
  19636. (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
  19637. prefix @samp{unix:}. For addresses using an IP address or domain name,
  19638. the default port is 80, and a different port can be specified
  19639. explicitly.
  19640. @end table
  19641. @end deftp
  19642. @deftp {Data Type} nginx-location-configuration
  19643. Data type representing the configuration of an nginx @code{location}
  19644. block. This type has the following parameters:
  19645. @table @asis
  19646. @item @code{uri}
  19647. URI which this location block matches.
  19648. @anchor{nginx-location-configuration body}
  19649. @item @code{body}
  19650. Body of the location block, specified as a list of strings. This can contain
  19651. many
  19652. configuration directives. For example, to pass requests to a upstream
  19653. server group defined using an @code{nginx-upstream-configuration} block,
  19654. the following directive would be specified in the body @samp{(list "proxy_pass
  19655. http://upstream-name;")}.
  19656. @end table
  19657. @end deftp
  19658. @deftp {Data Type} nginx-named-location-configuration
  19659. Data type representing the configuration of an nginx named location
  19660. block. Named location blocks are used for request redirection, and not
  19661. used for regular request processing. This type has the following
  19662. parameters:
  19663. @table @asis
  19664. @item @code{name}
  19665. Name to identify this location block.
  19666. @item @code{body}
  19667. @xref{nginx-location-configuration body}, as the body for named location
  19668. blocks can be used in a similar way to the
  19669. @code{nginx-location-configuration body}. One restriction is that the
  19670. body of a named location block cannot contain location blocks.
  19671. @end table
  19672. @end deftp
  19673. @subsubheading Varnish Cache
  19674. @cindex Varnish
  19675. Varnish is a fast cache server that sits in between web applications
  19676. and end users. It proxies requests from clients and caches the
  19677. accessed URLs such that multiple requests for the same resource only
  19678. creates one request to the back-end.
  19679. @defvr {Scheme Variable} varnish-service-type
  19680. Service type for the Varnish daemon.
  19681. @end defvr
  19682. @deftp {Data Type} varnish-configuration
  19683. Data type representing the @code{varnish} service configuration.
  19684. This type has the following parameters:
  19685. @table @asis
  19686. @item @code{package} (default: @code{varnish})
  19687. The Varnish package to use.
  19688. @item @code{name} (default: @code{"default"})
  19689. A name for this Varnish instance. Varnish will create a directory in
  19690. @file{/var/varnish/} with this name and keep temporary files there. If
  19691. the name starts with a forward slash, it is interpreted as an absolute
  19692. directory name.
  19693. Pass the @code{-n} argument to other Varnish programs to connect to the
  19694. named instance, e.g.@: @command{varnishncsa -n default}.
  19695. @item @code{backend} (default: @code{"localhost:8080"})
  19696. The backend to use. This option has no effect if @code{vcl} is set.
  19697. @item @code{vcl} (default: #f)
  19698. The @dfn{VCL} (Varnish Configuration Language) program to run. If this
  19699. is @code{#f}, Varnish will proxy @code{backend} using the default
  19700. configuration. Otherwise this must be a file-like object with valid
  19701. VCL syntax.
  19702. @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
  19703. For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
  19704. can do something along these lines:
  19705. @lisp
  19706. (define %gnu-mirror
  19707. (plain-file "gnu.vcl"
  19708. "vcl 4.1;
  19709. backend gnu @{ .host = \"www.gnu.org\"; @}"))
  19710. (operating-system
  19711. ;; @dots{}
  19712. (services (cons (service varnish-service-type
  19713. (varnish-configuration
  19714. (listen '(":80"))
  19715. (vcl %gnu-mirror)))
  19716. %base-services)))
  19717. @end lisp
  19718. The configuration of an already running Varnish instance can be inspected
  19719. and changed using the @command{varnishadm} program.
  19720. Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
  19721. @url{https://book.varnish-software.com/4.0/,Varnish Book} for
  19722. comprehensive documentation on Varnish and its configuration language.
  19723. @item @code{listen} (default: @code{'("localhost:80")})
  19724. List of addresses Varnish will listen on.
  19725. @item @code{storage} (default: @code{'("malloc,128m")})
  19726. List of storage backends that will be available in VCL.
  19727. @item @code{parameters} (default: @code{'()})
  19728. List of run-time parameters in the form @code{'(("parameter" . "value"))}.
  19729. @item @code{extra-options} (default: @code{'()})
  19730. Additional arguments to pass to the @command{varnishd} process.
  19731. @end table
  19732. @end deftp
  19733. @subsubheading Patchwork
  19734. @cindex Patchwork
  19735. Patchwork is a patch tracking system. It can collect patches sent to a
  19736. mailing list, and display them in a web interface.
  19737. @defvr {Scheme Variable} patchwork-service-type
  19738. Service type for Patchwork.
  19739. @end defvr
  19740. The following example is an example of a minimal service for Patchwork, for
  19741. the @code{patchwork.example.com} domain.
  19742. @lisp
  19743. (service patchwork-service-type
  19744. (patchwork-configuration
  19745. (domain "patchwork.example.com")
  19746. (settings-module
  19747. (patchwork-settings-module
  19748. (allowed-hosts (list domain))
  19749. (default-from-email "patchwork@@patchwork.example.com")))
  19750. (getmail-retriever-config
  19751. (getmail-retriever-configuration
  19752. (type "SimpleIMAPSSLRetriever")
  19753. (server "imap.example.com")
  19754. (port 993)
  19755. (username "patchwork")
  19756. (password-command
  19757. (list (file-append coreutils "/bin/cat")
  19758. "/etc/getmail-patchwork-imap-password"))
  19759. (extra-parameters
  19760. '((mailboxes . ("Patches"))))))))
  19761. @end lisp
  19762. There are three records for configuring the Patchwork service. The
  19763. @code{<patchwork-configuration>} relates to the configuration for Patchwork
  19764. within the HTTPD service.
  19765. The @code{settings-module} field within the @code{<patchwork-configuration>}
  19766. record can be populated with the @code{<patchwork-settings-module>} record,
  19767. which describes a settings module that is generated within the Guix store.
  19768. For the @code{database-configuration} field within the
  19769. @code{<patchwork-settings-module>}, the
  19770. @code{<patchwork-database-configuration>} must be used.
  19771. @deftp {Data Type} patchwork-configuration
  19772. Data type representing the Patchwork service configuration. This type has the
  19773. following parameters:
  19774. @table @asis
  19775. @item @code{patchwork} (default: @code{patchwork})
  19776. The Patchwork package to use.
  19777. @item @code{domain}
  19778. The domain to use for Patchwork, this is used in the HTTPD service virtual
  19779. host.
  19780. @item @code{settings-module}
  19781. The settings module to use for Patchwork. As a Django application, Patchwork
  19782. is configured with a Python module containing the settings. This can either be
  19783. an instance of the @code{<patchwork-settings-module>} record, any other record
  19784. that represents the settings in the store, or a directory outside of the
  19785. store.
  19786. @item @code{static-path} (default: @code{"/static/"})
  19787. The path under which the HTTPD service should serve the static files.
  19788. @item @code{getmail-retriever-config}
  19789. The getmail-retriever-configuration record value to use with
  19790. Patchwork. Getmail will be configured with this value, the messages will be
  19791. delivered to Patchwork.
  19792. @end table
  19793. @end deftp
  19794. @deftp {Data Type} patchwork-settings-module
  19795. Data type representing a settings module for Patchwork. Some of these
  19796. settings relate directly to Patchwork, but others relate to Django, the web
  19797. framework used by Patchwork, or the Django Rest Framework library. This type
  19798. has the following parameters:
  19799. @table @asis
  19800. @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
  19801. The database connection settings used for Patchwork. See the
  19802. @code{<patchwork-database-configuration>} record type for more information.
  19803. @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
  19804. Patchwork, as a Django web application uses a secret key for cryptographically
  19805. signing values. This file should contain a unique unpredictable value.
  19806. If this file does not exist, it will be created and populated with a random
  19807. value by the patchwork-setup shepherd service.
  19808. This setting relates to Django.
  19809. @item @code{allowed-hosts}
  19810. A list of valid hosts for this Patchwork service. This should at least include
  19811. the domain specified in the @code{<patchwork-configuration>} record.
  19812. This is a Django setting.
  19813. @item @code{default-from-email}
  19814. The email address from which Patchwork should send email by default.
  19815. This is a Patchwork setting.
  19816. @item @code{static-url} (default: @code{#f})
  19817. The URL to use when serving static assets. It can be part of a URL, or a full
  19818. URL, but must end in a @code{/}.
  19819. If the default value is used, the @code{static-path} value from the
  19820. @code{<patchwork-configuration>} record will be used.
  19821. This is a Django setting.
  19822. @item @code{admins} (default: @code{'()})
  19823. Email addresses to send the details of errors that occur. Each value should
  19824. be a list containing two elements, the name and then the email address.
  19825. This is a Django setting.
  19826. @item @code{debug?} (default: @code{#f})
  19827. Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
  19828. messages will be shown.
  19829. This is a Django setting.
  19830. @item @code{enable-rest-api?} (default: @code{#t})
  19831. Whether to enable the Patchwork REST API.
  19832. This is a Patchwork setting.
  19833. @item @code{enable-xmlrpc?} (default: @code{#t})
  19834. Whether to enable the XML RPC API.
  19835. This is a Patchwork setting.
  19836. @item @code{force-https-links?} (default: @code{#t})
  19837. Whether to use HTTPS links on Patchwork pages.
  19838. This is a Patchwork setting.
  19839. @item @code{extra-settings} (default: @code{""})
  19840. Extra code to place at the end of the Patchwork settings module.
  19841. @end table
  19842. @end deftp
  19843. @deftp {Data Type} patchwork-database-configuration
  19844. Data type representing the database configuration for Patchwork.
  19845. @table @asis
  19846. @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
  19847. The database engine to use.
  19848. @item @code{name} (default: @code{"patchwork"})
  19849. The name of the database to use.
  19850. @item @code{user} (default: @code{"httpd"})
  19851. The user to connect to the database as.
  19852. @item @code{password} (default: @code{""})
  19853. The password to use when connecting to the database.
  19854. @item @code{host} (default: @code{""})
  19855. The host to make the database connection to.
  19856. @item @code{port} (default: @code{""})
  19857. The port on which to connect to the database.
  19858. @end table
  19859. @end deftp
  19860. @subsubheading Mumi
  19861. @cindex Mumi, Debbugs Web interface
  19862. @cindex Debbugs, Mumi Web interface
  19863. @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
  19864. Web interface to the Debbugs bug tracker, by default for
  19865. @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
  19866. but it also fetches and indexes mail retrieved from Debbugs.
  19867. @defvr {Scheme Variable} mumi-service-type
  19868. This is the service type for Mumi.
  19869. @end defvr
  19870. @deftp {Data Type} mumi-configuration
  19871. Data type representing the Mumi service configuration. This type has the
  19872. following fields:
  19873. @table @asis
  19874. @item @code{mumi} (default: @code{mumi})
  19875. The Mumi package to use.
  19876. @item @code{mailer?} (default: @code{#true})
  19877. Whether to enable or disable the mailer component.
  19878. @item @code{mumi-configuration-sender}
  19879. The email address used as the sender for comments.
  19880. @item @code{mumi-configuration-smtp}
  19881. A URI to configure the SMTP settings for Mailutils. This could be
  19882. something like @code{sendmail:///path/to/bin/msmtp} or any other URI
  19883. supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
  19884. mailutils, GNU@tie{}Mailutils}.
  19885. @end table
  19886. @end deftp
  19887. @subsubheading FastCGI
  19888. @cindex fastcgi
  19889. @cindex fcgiwrap
  19890. FastCGI is an interface between the front-end and the back-end of a web
  19891. service. It is a somewhat legacy facility; new web services should
  19892. generally just talk HTTP between the front-end and the back-end.
  19893. However there are a number of back-end services such as PHP or the
  19894. optimized HTTP Git repository access that use FastCGI, so we have
  19895. support for it in Guix.
  19896. To use FastCGI, you configure the front-end web server (e.g., nginx) to
  19897. dispatch some subset of its requests to the fastcgi backend, which
  19898. listens on a local TCP or UNIX socket. There is an intermediary
  19899. @code{fcgiwrap} program that sits between the actual backend process and
  19900. the web server. The front-end indicates which backend program to run,
  19901. passing that information to the @code{fcgiwrap} process.
  19902. @defvr {Scheme Variable} fcgiwrap-service-type
  19903. A service type for the @code{fcgiwrap} FastCGI proxy.
  19904. @end defvr
  19905. @deftp {Data Type} fcgiwrap-configuration
  19906. Data type representing the configuration of the @code{fcgiwrap} service.
  19907. This type has the following parameters:
  19908. @table @asis
  19909. @item @code{package} (default: @code{fcgiwrap})
  19910. The fcgiwrap package to use.
  19911. @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
  19912. The socket on which the @code{fcgiwrap} process should listen, as a
  19913. string. Valid @var{socket} values include
  19914. @code{unix:@var{/path/to/unix/socket}},
  19915. @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
  19916. @code{tcp6:[@var{ipv6_addr}]:port}.
  19917. @item @code{user} (default: @code{fcgiwrap})
  19918. @itemx @code{group} (default: @code{fcgiwrap})
  19919. The user and group names, as strings, under which to run the
  19920. @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
  19921. the user asks for the specific user or group names @code{fcgiwrap} that
  19922. the corresponding user and/or group is present on the system.
  19923. It is possible to configure a FastCGI-backed web service to pass HTTP
  19924. authentication information from the front-end to the back-end, and to
  19925. allow @code{fcgiwrap} to run the back-end process as a corresponding
  19926. local user. To enable this capability on the back-end, run
  19927. @code{fcgiwrap} as the @code{root} user and group. Note that this
  19928. capability also has to be configured on the front-end as well.
  19929. @end table
  19930. @end deftp
  19931. @cindex php-fpm
  19932. PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
  19933. with some additional features useful for sites of any size.
  19934. These features include:
  19935. @itemize @bullet
  19936. @item Adaptive process spawning
  19937. @item Basic statistics (similar to Apache's mod_status)
  19938. @item Advanced process management with graceful stop/start
  19939. @item Ability to start workers with different uid/gid/chroot/environment
  19940. and different php.ini (replaces safe_mode)
  19941. @item Stdout & stderr logging
  19942. @item Emergency restart in case of accidental opcode cache destruction
  19943. @item Accelerated upload support
  19944. @item Support for a "slowlog"
  19945. @item Enhancements to FastCGI, such as fastcgi_finish_request() -
  19946. a special function to finish request & flush all data while continuing to do
  19947. something time-consuming (video converting, stats processing, etc.)
  19948. @end itemize
  19949. ...@: and much more.
  19950. @defvr {Scheme Variable} php-fpm-service-type
  19951. A Service type for @code{php-fpm}.
  19952. @end defvr
  19953. @deftp {Data Type} php-fpm-configuration
  19954. Data Type for php-fpm service configuration.
  19955. @table @asis
  19956. @item @code{php} (default: @code{php})
  19957. The php package to use.
  19958. @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
  19959. The address on which to accept FastCGI requests. Valid syntaxes are:
  19960. @table @asis
  19961. @item @code{"ip.add.re.ss:port"}
  19962. Listen on a TCP socket to a specific address on a specific port.
  19963. @item @code{"port"}
  19964. Listen on a TCP socket to all addresses on a specific port.
  19965. @item @code{"/path/to/unix/socket"}
  19966. Listen on a unix socket.
  19967. @end table
  19968. @item @code{user} (default: @code{php-fpm})
  19969. User who will own the php worker processes.
  19970. @item @code{group} (default: @code{php-fpm})
  19971. Group of the worker processes.
  19972. @item @code{socket-user} (default: @code{php-fpm})
  19973. User who can speak to the php-fpm socket.
  19974. @item @code{socket-group} (default: @code{nginx})
  19975. Group that can speak to the php-fpm socket.
  19976. @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
  19977. The process id of the php-fpm process is written to this file
  19978. once the service has started.
  19979. @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
  19980. Log for the php-fpm master process.
  19981. @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
  19982. Detailed settings for the php-fpm process manager.
  19983. Must be one of:
  19984. @table @asis
  19985. @item @code{<php-fpm-dynamic-process-manager-configuration>}
  19986. @item @code{<php-fpm-static-process-manager-configuration>}
  19987. @item @code{<php-fpm-on-demand-process-manager-configuration>}
  19988. @end table
  19989. @item @code{display-errors} (default @code{#f})
  19990. Determines whether php errors and warning should be sent to clients
  19991. and displayed in their browsers.
  19992. This is useful for local php development, but a security risk for public sites,
  19993. as error messages can reveal passwords and personal data.
  19994. @item @code{timezone} (default @code{#f})
  19995. Specifies @code{php_admin_value[date.timezone]} parameter.
  19996. @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
  19997. This file will log the @code{stderr} outputs of php worker processes.
  19998. Can be set to @code{#f} to disable logging.
  19999. @item @code{file} (default @code{#f})
  20000. An optional override of the whole configuration.
  20001. You can use the @code{mixed-text-file} function or an absolute filepath for it.
  20002. @item @code{php-ini-file} (default @code{#f})
  20003. An optional override of the default php settings.
  20004. It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
  20005. You can use the @code{mixed-text-file} function or an absolute filepath for it.
  20006. For local development it is useful to set a higher timeout and memory
  20007. limit for spawned php processes. This be accomplished with the
  20008. following operating system configuration snippet:
  20009. @lisp
  20010. (define %local-php-ini
  20011. (plain-file "php.ini"
  20012. "memory_limit = 2G
  20013. max_execution_time = 1800"))
  20014. (operating-system
  20015. ;; @dots{}
  20016. (services (cons (service php-fpm-service-type
  20017. (php-fpm-configuration
  20018. (php-ini-file %local-php-ini)))
  20019. %base-services)))
  20020. @end lisp
  20021. Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
  20022. directives} for comprehensive documentation on the acceptable
  20023. @file{php.ini} directives.
  20024. @end table
  20025. @end deftp
  20026. @deftp {Data type} php-fpm-dynamic-process-manager-configuration
  20027. Data Type for the @code{dynamic} php-fpm process manager. With the
  20028. @code{dynamic} process manager, spare worker processes are kept around
  20029. based on it's configured limits.
  20030. @table @asis
  20031. @item @code{max-children} (default: @code{5})
  20032. Maximum of worker processes.
  20033. @item @code{start-servers} (default: @code{2})
  20034. How many worker processes should be started on start-up.
  20035. @item @code{min-spare-servers} (default: @code{1})
  20036. How many spare worker processes should be kept around at minimum.
  20037. @item @code{max-spare-servers} (default: @code{3})
  20038. How many spare worker processes should be kept around at maximum.
  20039. @end table
  20040. @end deftp
  20041. @deftp {Data type} php-fpm-static-process-manager-configuration
  20042. Data Type for the @code{static} php-fpm process manager. With the
  20043. @code{static} process manager, an unchanging number of worker processes
  20044. are created.
  20045. @table @asis
  20046. @item @code{max-children} (default: @code{5})
  20047. Maximum of worker processes.
  20048. @end table
  20049. @end deftp
  20050. @deftp {Data type} php-fpm-on-demand-process-manager-configuration
  20051. Data Type for the @code{on-demand} php-fpm process manager. With the
  20052. @code{on-demand} process manager, worker processes are only created as
  20053. requests arrive.
  20054. @table @asis
  20055. @item @code{max-children} (default: @code{5})
  20056. Maximum of worker processes.
  20057. @item @code{process-idle-timeout} (default: @code{10})
  20058. The time in seconds after which a process with no requests is killed.
  20059. @end table
  20060. @end deftp
  20061. @deffn {Scheme Procedure} nginx-php-location @
  20062. [#:nginx-package nginx] @
  20063. [socket (string-append "/var/run/php" @
  20064. (version-major (package-version php)) @
  20065. "-fpm.sock")]
  20066. A helper function to quickly add php to an @code{nginx-server-configuration}.
  20067. @end deffn
  20068. A simple services setup for nginx with php can look like this:
  20069. @lisp
  20070. (services (cons* (service dhcp-client-service-type)
  20071. (service php-fpm-service-type)
  20072. (service nginx-service-type
  20073. (nginx-server-configuration
  20074. (server-name '("example.com"))
  20075. (root "/srv/http/")
  20076. (locations
  20077. (list (nginx-php-location)))
  20078. (listen '("80"))
  20079. (ssl-certificate #f)
  20080. (ssl-certificate-key #f)))
  20081. %base-services))
  20082. @end lisp
  20083. @cindex cat-avatar-generator
  20084. The cat avatar generator is a simple service to demonstrate the use of php-fpm
  20085. in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
  20086. the hash of a user's email address.
  20087. @deffn {Scheme Procedure} cat-avatar-generator-service @
  20088. [#:cache-dir "/var/cache/cat-avatar-generator"] @
  20089. [#:package cat-avatar-generator] @
  20090. [#:configuration (nginx-server-configuration)]
  20091. Returns an nginx-server-configuration that inherits @code{configuration}. It
  20092. extends the nginx configuration to add a server block that serves @code{package},
  20093. a version of cat-avatar-generator. During execution, cat-avatar-generator will
  20094. be able to use @code{cache-dir} as its cache directory.
  20095. @end deffn
  20096. A simple setup for cat-avatar-generator can look like this:
  20097. @lisp
  20098. (services (cons* (cat-avatar-generator-service
  20099. #:configuration
  20100. (nginx-server-configuration
  20101. (server-name '("example.com"))))
  20102. ...
  20103. %base-services))
  20104. @end lisp
  20105. @subsubheading Hpcguix-web
  20106. @cindex hpcguix-web
  20107. The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
  20108. program is a customizable web interface to browse Guix packages,
  20109. initially designed for users of high-performance computing (HPC)
  20110. clusters.
  20111. @defvr {Scheme Variable} hpcguix-web-service-type
  20112. The service type for @code{hpcguix-web}.
  20113. @end defvr
  20114. @deftp {Data Type} hpcguix-web-configuration
  20115. Data type for the hpcguix-web service configuration.
  20116. @table @asis
  20117. @item @code{specs}
  20118. A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
  20119. configuration. The main items available in this spec are:
  20120. @table @asis
  20121. @item @code{title-prefix} (default: @code{"hpcguix | "})
  20122. The page title prefix.
  20123. @item @code{guix-command} (default: @code{"guix"})
  20124. The @command{guix} command.
  20125. @item @code{package-filter-proc} (default: @code{(const #t)})
  20126. A procedure specifying how to filter packages that are displayed.
  20127. @item @code{package-page-extension-proc} (default: @code{(const '())})
  20128. Extension package for @code{hpcguix-web}.
  20129. @item @code{menu} (default: @code{'()})
  20130. Additional entry in page @code{menu}.
  20131. @item @code{channels} (default: @code{%default-channels})
  20132. List of channels from which the package list is built (@pxref{Channels}).
  20133. @item @code{package-list-expiration} (default: @code{(* 12 3600)})
  20134. The expiration time, in seconds, after which the package list is rebuilt from
  20135. the latest instances of the given channels.
  20136. @end table
  20137. See the hpcguix-web repository for a
  20138. @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
  20139. complete example}.
  20140. @item @code{package} (default: @code{hpcguix-web})
  20141. The hpcguix-web package to use.
  20142. @end table
  20143. @end deftp
  20144. A typical hpcguix-web service declaration looks like this:
  20145. @lisp
  20146. (service hpcguix-web-service-type
  20147. (hpcguix-web-configuration
  20148. (specs
  20149. #~(define site-config
  20150. (hpcweb-configuration
  20151. (title-prefix "Guix-HPC - ")
  20152. (menu '(("/about" "ABOUT"))))))))
  20153. @end lisp
  20154. @quotation Note
  20155. The hpcguix-web service periodically updates the package list it publishes by
  20156. pulling channels from Git. To that end, it needs to access X.509 certificates
  20157. so that it can authenticate Git servers when communicating over HTTPS, and it
  20158. assumes that @file{/etc/ssl/certs} contains those certificates.
  20159. Thus, make sure to add @code{nss-certs} or another certificate package to the
  20160. @code{packages} field of your configuration. @ref{X.509 Certificates}, for
  20161. more information on X.509 certificates.
  20162. @end quotation
  20163. @subsubheading gmnisrv
  20164. @cindex gmnisrv
  20165. The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
  20166. simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
  20167. @deffn {Scheme Variable} gmnisrv-service-type
  20168. This is the type of the gmnisrv service, whose value should be a
  20169. @code{gmnisrv-configuration} object, as in this example:
  20170. @lisp
  20171. (service gmnisrv-service-type
  20172. (gmnisrv-configuration
  20173. (config-file (local-file "./my-gmnisrv.ini"))))
  20174. @end lisp
  20175. @end deffn
  20176. @deftp {Data Type} gmnisrv-configuration
  20177. Data type representing the configuration of gmnisrv.
  20178. @table @asis
  20179. @item @code{package} (default: @var{gmnisrv})
  20180. Package object of the gmnisrv server.
  20181. @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
  20182. File-like object of the gmnisrv configuration file to use. The default
  20183. configuration listens on port 1965 and serves files from
  20184. @file{/srv/gemini}. Certificates are stored in
  20185. @file{/var/lib/gemini/certs}. For more information, run @command{man
  20186. gmnisrv} and @command{man gmnisrv.ini}.
  20187. @end table
  20188. @end deftp
  20189. @subsubheading Agate
  20190. @cindex agate
  20191. The @uref{gemini://qwertqwefsday.eu/agate.gmi, Agate}
  20192. (@uref{https://github.com/mbrubeck/agate, GitHub page over HTTPS})
  20193. program is a simple @uref{https://gemini.circumlunar.space/, Gemini}
  20194. protocol server written in Rust.
  20195. @deffn {Scheme Variable} agate-service-type
  20196. This is the type of the agate service, whose value should be an
  20197. @code{agate-service-type} object, as in this example:
  20198. @lisp
  20199. (service agate-service-type
  20200. (agate-configuration
  20201. (content "/srv/gemini")
  20202. (cert "/srv/cert.pem")
  20203. (key "/srv/key.rsa")))
  20204. @end lisp
  20205. The example above represents the minimal tweaking necessary to get Agate
  20206. up and running. Specifying the path to the certificate and key is
  20207. always necessary, as the Gemini protocol requires TLS by default.
  20208. To obtain a certificate and a key, you could, for example, use OpenSSL,
  20209. running a command similar to the following example:
  20210. @example
  20211. openssl req -x509 -newkey rsa:4096 -keyout key.rsa -out cert.pem \
  20212. -days 3650 -nodes -subj "/CN=example.com"
  20213. @end example
  20214. Of course, you'll have to replace @i{example.com} with your own domain
  20215. name, and then point the Agate configuration towards the path of the
  20216. generated key and certificate.
  20217. @end deffn
  20218. @deftp {Data Type} agate-configuration
  20219. Data type representing the configuration of Agate.
  20220. @table @asis
  20221. @item @code{package} (default: @code{agate})
  20222. The package object of the Agate server.
  20223. @item @code{content} (default: @file{"/srv/gemini"})
  20224. The directory from which Agate will serve files.
  20225. @item @code{cert} (default: @code{#f})
  20226. The path to the TLS certificate PEM file to be used for encrypted
  20227. connections. Must be filled in with a value from the user.
  20228. @item @code{key} (default: @code{#f})
  20229. The path to the PKCS8 private key file to be used for encrypted
  20230. connections. Must be filled in with a value from the user.
  20231. @item @code{addr} (default: @code{'("0.0.0.0:1965" "[::]:1965")})
  20232. A list of the addresses to listen on.
  20233. @item @code{hostname} (default: @code{#f})
  20234. The domain name of this Gemini server. Optional.
  20235. @item @code{lang} (default: @code{#f})
  20236. RFC 4646 language code(s) for text/gemini documents. Optional.
  20237. @item @code{silent?} (default: @code{#f})
  20238. Set to @code{#t} to disable logging output.
  20239. @item @code{serve-secret?} (default: @code{#f})
  20240. Set to @code{#t} to serve secret files (files/directories starting with
  20241. a dot).
  20242. @item @code{log-ip?} (default: @code{#t})
  20243. Whether or not to output IP addresses when logging.
  20244. @item @code{user} (default: @code{"agate"})
  20245. Owner of the @code{agate} process.
  20246. @item @code{group} (default: @code{"agate"})
  20247. Owner's group of the @code{agate} process.
  20248. @item @code{log-file} (default: @file{"/var/log/agate.log"})
  20249. The file which should store the logging output of Agate.
  20250. @end table
  20251. @end deftp
  20252. @node Certificate Services
  20253. @subsection Certificate Services
  20254. @cindex Web
  20255. @cindex HTTP, HTTPS
  20256. @cindex Let's Encrypt
  20257. @cindex TLS certificates
  20258. The @code{(gnu services certbot)} module provides a service to
  20259. automatically obtain a valid TLS certificate from the Let's Encrypt
  20260. certificate authority. These certificates can then be used to serve
  20261. content securely over HTTPS or other TLS-based protocols, with the
  20262. knowledge that the client will be able to verify the server's
  20263. authenticity.
  20264. @url{https://letsencrypt.org/, Let's Encrypt} provides the
  20265. @code{certbot} tool to automate the certification process. This tool
  20266. first securely generates a key on the server. It then makes a request
  20267. to the Let's Encrypt certificate authority (CA) to sign the key. The CA
  20268. checks that the request originates from the host in question by using a
  20269. challenge-response protocol, requiring the server to provide its
  20270. response over HTTP@. If that protocol completes successfully, the CA
  20271. signs the key, resulting in a certificate. That certificate is valid
  20272. for a limited period of time, and therefore to continue to provide TLS
  20273. services, the server needs to periodically ask the CA to renew its
  20274. signature.
  20275. The certbot service automates this process: the initial key
  20276. generation, the initial certification request to the Let's Encrypt
  20277. service, the web server challenge/response integration, writing the
  20278. certificate to disk, the automated periodic renewals, and the deployment
  20279. tasks associated with the renewal (e.g.@: reloading services, copying keys
  20280. with different permissions).
  20281. Certbot is run twice a day, at a random minute within the hour. It
  20282. won't do anything until your certificates are due for renewal or
  20283. revoked, but running it regularly would give your service a chance of
  20284. staying online in case a Let's Encrypt-initiated revocation happened for
  20285. some reason.
  20286. By using this service, you agree to the ACME Subscriber Agreement, which
  20287. can be found there:
  20288. @url{https://acme-v01.api.letsencrypt.org/directory}.
  20289. @defvr {Scheme Variable} certbot-service-type
  20290. A service type for the @code{certbot} Let's Encrypt client. Its value
  20291. must be a @code{certbot-configuration} record as in this example:
  20292. @lisp
  20293. (define %nginx-deploy-hook
  20294. (program-file
  20295. "nginx-deploy-hook"
  20296. #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
  20297. (kill pid SIGHUP))))
  20298. (service certbot-service-type
  20299. (certbot-configuration
  20300. (email "foo@@example.net")
  20301. (certificates
  20302. (list
  20303. (certificate-configuration
  20304. (domains '("example.net" "www.example.net"))
  20305. (deploy-hook %nginx-deploy-hook))
  20306. (certificate-configuration
  20307. (domains '("bar.example.net")))))))
  20308. @end lisp
  20309. See below for details about @code{certbot-configuration}.
  20310. @end defvr
  20311. @deftp {Data Type} certbot-configuration
  20312. Data type representing the configuration of the @code{certbot} service.
  20313. This type has the following parameters:
  20314. @table @asis
  20315. @item @code{package} (default: @code{certbot})
  20316. The certbot package to use.
  20317. @item @code{webroot} (default: @code{/var/www})
  20318. The directory from which to serve the Let's Encrypt challenge/response
  20319. files.
  20320. @item @code{certificates} (default: @code{()})
  20321. A list of @code{certificates-configuration}s for which to generate
  20322. certificates and request signatures. Each certificate has a @code{name}
  20323. and several @code{domains}.
  20324. @item @code{email} (default: @code{#f})
  20325. Optional email address used for registration and recovery contact.
  20326. Setting this is encouraged as it allows you to receive important
  20327. notifications about the account and issued certificates.
  20328. @item @code{server} (default: @code{#f})
  20329. Optional URL of ACME server. Setting this overrides certbot's default,
  20330. which is the Let's Encrypt server.
  20331. @item @code{rsa-key-size} (default: @code{2048})
  20332. Size of the RSA key.
  20333. @item @code{default-location} (default: @i{see below})
  20334. The default @code{nginx-location-configuration}. Because @code{certbot}
  20335. needs to be able to serve challenges and responses, it needs to be able
  20336. to run a web server. It does so by extending the @code{nginx} web
  20337. service with an @code{nginx-server-configuration} listening on the
  20338. @var{domains} on port 80, and which has a
  20339. @code{nginx-location-configuration} for the @code{/.well-known/} URI
  20340. path subspace used by Let's Encrypt. @xref{Web Services}, for more on
  20341. these nginx configuration data types.
  20342. Requests to other URL paths will be matched by the
  20343. @code{default-location}, which if present is added to all
  20344. @code{nginx-server-configuration}s.
  20345. By default, the @code{default-location} will issue a redirect from
  20346. @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
  20347. you to define what to serve on your site via @code{https}.
  20348. Pass @code{#f} to not issue a default location.
  20349. @end table
  20350. @end deftp
  20351. @deftp {Data Type} certificate-configuration
  20352. Data type representing the configuration of a certificate.
  20353. This type has the following parameters:
  20354. @table @asis
  20355. @item @code{name} (default: @i{see below})
  20356. This name is used by Certbot for housekeeping and in file paths; it
  20357. doesn't affect the content of the certificate itself. To see
  20358. certificate names, run @code{certbot certificates}.
  20359. Its default is the first provided domain.
  20360. @item @code{domains} (default: @code{()})
  20361. The first domain provided will be the subject CN of the certificate, and
  20362. all domains will be Subject Alternative Names on the certificate.
  20363. @item @code{challenge} (default: @code{#f})
  20364. The challenge type that has to be run by certbot. If @code{#f} is specified,
  20365. default to the HTTP challenge. If a value is specified, defaults to the
  20366. manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
  20367. the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
  20368. and gives Let's Encrypt permission to log the public IP address of the
  20369. requesting machine.
  20370. @item @code{authentication-hook} (default: @code{#f})
  20371. Command to be run in a shell once for each certificate challenge to be
  20372. answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
  20373. will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
  20374. contains the validation string and @code{$CERTBOT_TOKEN} contains the
  20375. file name of the resource requested when performing an HTTP-01 challenge.
  20376. @item @code{cleanup-hook} (default: @code{#f})
  20377. Command to be run in a shell once for each certificate challenge that
  20378. have been answered by the @code{auth-hook}. For this command, the shell
  20379. variables available in the @code{auth-hook} script are still available, and
  20380. additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
  20381. of the @code{auth-hook} script.
  20382. @item @code{deploy-hook} (default: @code{#f})
  20383. Command to be run in a shell once for each successfully issued
  20384. certificate. For this command, the shell variable
  20385. @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
  20386. example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
  20387. certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
  20388. contain a space-delimited list of renewed certificate domains (for
  20389. example, @samp{"example.com www.example.com"}.
  20390. @end table
  20391. @end deftp
  20392. For each @code{certificate-configuration}, the certificate is saved to
  20393. @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
  20394. saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
  20395. @node DNS Services
  20396. @subsection DNS Services
  20397. @cindex DNS (domain name system)
  20398. @cindex domain name system (DNS)
  20399. The @code{(gnu services dns)} module provides services related to the
  20400. @dfn{domain name system} (DNS). It provides a server service for hosting
  20401. an @emph{authoritative} DNS server for multiple zones, slave or master.
  20402. This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
  20403. caching and forwarding DNS server for the LAN, which uses
  20404. @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
  20405. @subsubheading Knot Service
  20406. An example configuration of an authoritative server for two zones, one master
  20407. and one slave, is:
  20408. @lisp
  20409. (define-zone-entries example.org.zone
  20410. ;; Name TTL Class Type Data
  20411. ("@@" "" "IN" "A" "127.0.0.1")
  20412. ("@@" "" "IN" "NS" "ns")
  20413. ("ns" "" "IN" "A" "127.0.0.1"))
  20414. (define master-zone
  20415. (knot-zone-configuration
  20416. (domain "example.org")
  20417. (zone (zone-file
  20418. (origin "example.org")
  20419. (entries example.org.zone)))))
  20420. (define slave-zone
  20421. (knot-zone-configuration
  20422. (domain "plop.org")
  20423. (dnssec-policy "default")
  20424. (master (list "plop-master"))))
  20425. (define plop-master
  20426. (knot-remote-configuration
  20427. (id "plop-master")
  20428. (address (list "208.76.58.171"))))
  20429. (operating-system
  20430. ;; ...
  20431. (services (cons* (service knot-service-type
  20432. (knot-configuration
  20433. (remotes (list plop-master))
  20434. (zones (list master-zone slave-zone))))
  20435. ;; ...
  20436. %base-services)))
  20437. @end lisp
  20438. @deffn {Scheme Variable} knot-service-type
  20439. This is the type for the Knot DNS server.
  20440. Knot DNS is an authoritative DNS server, meaning that it can serve multiple
  20441. zones, that is to say domain names you would buy from a registrar. This server
  20442. is not a resolver, meaning that it can only resolve names for which it is
  20443. authoritative. This server can be configured to serve zones as a master server
  20444. or a slave server as a per-zone basis. Slave zones will get their data from
  20445. masters, and will serve it as an authoritative server. From the point of view
  20446. of a resolver, there is no difference between master and slave.
  20447. The following data types are used to configure the Knot DNS server:
  20448. @end deffn
  20449. @deftp {Data Type} knot-key-configuration
  20450. Data type representing a key.
  20451. This type has the following parameters:
  20452. @table @asis
  20453. @item @code{id} (default: @code{""})
  20454. An identifier for other configuration fields to refer to this key. IDs must
  20455. be unique and must not be empty.
  20456. @item @code{algorithm} (default: @code{#f})
  20457. The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
  20458. @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
  20459. and @code{'hmac-sha512}.
  20460. @item @code{secret} (default: @code{""})
  20461. The secret key itself.
  20462. @end table
  20463. @end deftp
  20464. @deftp {Data Type} knot-acl-configuration
  20465. Data type representing an Access Control List (ACL) configuration.
  20466. This type has the following parameters:
  20467. @table @asis
  20468. @item @code{id} (default: @code{""})
  20469. An identifier for other configuration fields to refer to this key. IDs must be
  20470. unique and must not be empty.
  20471. @item @code{address} (default: @code{'()})
  20472. An ordered list of IP addresses, network subnets, or network ranges represented
  20473. with strings. The query must match one of them. Empty value means that
  20474. address match is not required.
  20475. @item @code{key} (default: @code{'()})
  20476. An ordered list of references to keys represented with strings. The string
  20477. must match a key ID defined in a @code{knot-key-configuration}. No key means
  20478. that a key is not require to match that ACL.
  20479. @item @code{action} (default: @code{'()})
  20480. An ordered list of actions that are permitted or forbidden by this ACL@. Possible
  20481. values are lists of zero or more elements from @code{'transfer}, @code{'notify}
  20482. and @code{'update}.
  20483. @item @code{deny?} (default: @code{#f})
  20484. When true, the ACL defines restrictions. Listed actions are forbidden. When
  20485. false, listed actions are allowed.
  20486. @end table
  20487. @end deftp
  20488. @deftp {Data Type} zone-entry
  20489. Data type representing a record entry in a zone file.
  20490. This type has the following parameters:
  20491. @table @asis
  20492. @item @code{name} (default: @code{"@@"})
  20493. The name of the record. @code{"@@"} refers to the origin of the zone. Names
  20494. are relative to the origin of the zone. For example, in the @code{example.org}
  20495. zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
  20496. Names ending with a dot are absolute, which means that @code{"ns.example.org."}
  20497. refers to @code{ns.example.org}.
  20498. @item @code{ttl} (default: @code{""})
  20499. The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
  20500. @item @code{class} (default: @code{"IN"})
  20501. The class of the record. Knot currently supports only @code{"IN"} and
  20502. partially @code{"CH"}.
  20503. @item @code{type} (default: @code{"A"})
  20504. The type of the record. Common types include A (IPv4 address), AAAA (IPv6
  20505. address), NS (Name Server) and MX (Mail eXchange). Many other types are
  20506. defined.
  20507. @item @code{data} (default: @code{""})
  20508. The data contained in the record. For instance an IP address associated with
  20509. an A record, or a domain name associated with an NS record. Remember that
  20510. domain names are relative to the origin unless they end with a dot.
  20511. @end table
  20512. @end deftp
  20513. @deftp {Data Type} zone-file
  20514. Data type representing the content of a zone file.
  20515. This type has the following parameters:
  20516. @table @asis
  20517. @item @code{entries} (default: @code{'()})
  20518. The list of entries. The SOA record is taken care of, so you don't need to
  20519. put it in the list of entries. This list should probably contain an entry
  20520. for your primary authoritative DNS server. Other than using a list of entries
  20521. directly, you can use @code{define-zone-entries} to define a object containing
  20522. the list of entries more easily, that you can later pass to the @code{entries}
  20523. field of the @code{zone-file}.
  20524. @item @code{origin} (default: @code{""})
  20525. The name of your zone. This parameter cannot be empty.
  20526. @item @code{ns} (default: @code{"ns"})
  20527. The domain of your primary authoritative DNS server. The name is relative to
  20528. the origin, unless it ends with a dot. It is mandatory that this primary
  20529. DNS server corresponds to an NS record in the zone and that it is associated
  20530. to an IP address in the list of entries.
  20531. @item @code{mail} (default: @code{"hostmaster"})
  20532. An email address people can contact you at, as the owner of the zone. This
  20533. is translated as @code{<mail>@@<origin>}.
  20534. @item @code{serial} (default: @code{1})
  20535. The serial number of the zone. As this is used to keep track of changes by
  20536. both slaves and resolvers, it is mandatory that it @emph{never} decreases.
  20537. Always increment it when you make a change in your zone.
  20538. @item @code{refresh} (default: @code{(* 2 24 3600)})
  20539. The frequency at which slaves will do a zone transfer. This value is a number
  20540. of seconds. It can be computed by multiplications or with
  20541. @code{(string->duration)}.
  20542. @item @code{retry} (default: @code{(* 15 60)})
  20543. The period after which a slave will retry to contact its master when it fails
  20544. to do so a first time.
  20545. @item @code{expiry} (default: @code{(* 14 24 3600)})
  20546. Default TTL of records. Existing records are considered correct for at most
  20547. this amount of time. After this period, resolvers will invalidate their cache
  20548. and check again that it still exists.
  20549. @item @code{nx} (default: @code{3600})
  20550. Default TTL of inexistant records. This delay is usually short because you want
  20551. your new domains to reach everyone quickly.
  20552. @end table
  20553. @end deftp
  20554. @deftp {Data Type} knot-remote-configuration
  20555. Data type representing a remote configuration.
  20556. This type has the following parameters:
  20557. @table @asis
  20558. @item @code{id} (default: @code{""})
  20559. An identifier for other configuration fields to refer to this remote. IDs must
  20560. be unique and must not be empty.
  20561. @item @code{address} (default: @code{'()})
  20562. An ordered list of destination IP addresses. Addresses are tried in sequence.
  20563. An optional port can be given with the @@ separator. For instance:
  20564. @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
  20565. @item @code{via} (default: @code{'()})
  20566. An ordered list of source IP addresses. An empty list will have Knot choose
  20567. an appropriate source IP@. An optional port can be given with the @@ separator.
  20568. The default is to choose at random.
  20569. @item @code{key} (default: @code{#f})
  20570. A reference to a key, that is a string containing the identifier of a key
  20571. defined in a @code{knot-key-configuration} field.
  20572. @end table
  20573. @end deftp
  20574. @deftp {Data Type} knot-keystore-configuration
  20575. Data type representing a keystore to hold dnssec keys.
  20576. This type has the following parameters:
  20577. @table @asis
  20578. @item @code{id} (default: @code{""})
  20579. The id of the keystore. It must not be empty.
  20580. @item @code{backend} (default: @code{'pem})
  20581. The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
  20582. @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
  20583. The configuration string of the backend. An example for the PKCS#11 is:
  20584. @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
  20585. For the pem backend, the string represents a path in the file system.
  20586. @end table
  20587. @end deftp
  20588. @deftp {Data Type} knot-policy-configuration
  20589. Data type representing a dnssec policy. Knot DNS is able to automatically
  20590. sign your zones. It can either generate and manage your keys automatically or
  20591. use keys that you generate.
  20592. Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
  20593. used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
  20594. zone. In order to be trusted, the KSK needs to be present in the parent zone
  20595. (usually a top-level domain). If your registrar supports dnssec, you will
  20596. have to send them your KSK's hash so they can add a DS record in their zone.
  20597. This is not automated and need to be done each time you change your KSK.
  20598. The policy also defines the lifetime of keys. Usually, ZSK can be changed
  20599. easily and use weaker cryptographic functions (they use lower parameters) in
  20600. order to sign records quickly, so they are changed often. The KSK however
  20601. requires manual interaction with the registrar, so they are changed less often
  20602. and use stronger parameters because they sign only one record.
  20603. This type has the following parameters:
  20604. @table @asis
  20605. @item @code{id} (default: @code{""})
  20606. The id of the policy. It must not be empty.
  20607. @item @code{keystore} (default: @code{"default"})
  20608. A reference to a keystore, that is a string containing the identifier of a
  20609. keystore defined in a @code{knot-keystore-configuration} field. The
  20610. @code{"default"} identifier means the default keystore (a kasp database that
  20611. was setup by this service).
  20612. @item @code{manual?} (default: @code{#f})
  20613. Whether the key management is manual or automatic.
  20614. @item @code{single-type-signing?} (default: @code{#f})
  20615. When @code{#t}, use the Single-Type Signing Scheme.
  20616. @item @code{algorithm} (default: @code{"ecdsap256sha256"})
  20617. An algorithm of signing keys and issued signatures.
  20618. @item @code{ksk-size} (default: @code{256})
  20619. The length of the KSK@. Note that this value is correct for the default
  20620. algorithm, but would be unsecure for other algorithms.
  20621. @item @code{zsk-size} (default: @code{256})
  20622. The length of the ZSK@. Note that this value is correct for the default
  20623. algorithm, but would be unsecure for other algorithms.
  20624. @item @code{dnskey-ttl} (default: @code{'default})
  20625. The TTL value for DNSKEY records added into zone apex. The special
  20626. @code{'default} value means same as the zone SOA TTL.
  20627. @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
  20628. The period between ZSK publication and the next rollover initiation.
  20629. @item @code{propagation-delay} (default: @code{(* 24 3600)})
  20630. An extra delay added for each key rollover step. This value should be high
  20631. enough to cover propagation of data from the master server to all slaves.
  20632. @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
  20633. A validity period of newly issued signatures.
  20634. @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
  20635. A period how long before a signature expiration the signature will be refreshed.
  20636. @item @code{nsec3?} (default: @code{#f})
  20637. When @code{#t}, NSEC3 will be used instead of NSEC.
  20638. @item @code{nsec3-iterations} (default: @code{5})
  20639. The number of additional times the hashing is performed.
  20640. @item @code{nsec3-salt-length} (default: @code{8})
  20641. The length of a salt field in octets, which is appended to the original owner
  20642. name before hashing.
  20643. @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
  20644. The validity period of newly issued salt field.
  20645. @end table
  20646. @end deftp
  20647. @deftp {Data Type} knot-zone-configuration
  20648. Data type representing a zone served by Knot.
  20649. This type has the following parameters:
  20650. @table @asis
  20651. @item @code{domain} (default: @code{""})
  20652. The domain served by this configuration. It must not be empty.
  20653. @item @code{file} (default: @code{""})
  20654. The file where this zone is saved. This parameter is ignored by master zones.
  20655. Empty means default location that depends on the domain name.
  20656. @item @code{zone} (default: @code{(zone-file)})
  20657. The content of the zone file. This parameter is ignored by slave zones. It
  20658. must contain a zone-file record.
  20659. @item @code{master} (default: @code{'()})
  20660. A list of master remotes. When empty, this zone is a master. When set, this
  20661. zone is a slave. This is a list of remotes identifiers.
  20662. @item @code{ddns-master} (default: @code{#f})
  20663. The main master. When empty, it defaults to the first master in the list of
  20664. masters.
  20665. @item @code{notify} (default: @code{'()})
  20666. A list of slave remote identifiers.
  20667. @item @code{acl} (default: @code{'()})
  20668. A list of acl identifiers.
  20669. @item @code{semantic-checks?} (default: @code{#f})
  20670. When set, this adds more semantic checks to the zone.
  20671. @item @code{disable-any?} (default: @code{#f})
  20672. When set, this forbids queries of the ANY type.
  20673. @item @code{zonefile-sync} (default: @code{0})
  20674. The delay between a modification in memory and on disk. 0 means immediate
  20675. synchronization.
  20676. @item @code{zonefile-load} (default: @code{#f})
  20677. The way the zone file contents are applied during zone load. Possible values
  20678. are:
  20679. @itemize
  20680. @item @code{#f} for using the default value from Knot,
  20681. @item @code{'none} for not using the zone file at all,
  20682. @item @code{'difference} for computing the difference between already available
  20683. contents and zone contents and applying it to the current zone contents,
  20684. @item @code{'difference-no-serial} for the same as @code{'difference}, but
  20685. ignoring the SOA serial in the zone file, while the server takes care of it
  20686. automatically.
  20687. @item @code{'whole} for loading zone contents from the zone file.
  20688. @end itemize
  20689. @item @code{journal-content} (default: @code{#f})
  20690. The way the journal is used to store zone and its changes. Possible values
  20691. are @code{'none} to not use it at all, @code{'changes} to store changes and
  20692. @code{'all} to store contents. @code{#f} does not set this option, so the
  20693. default value from Knot is used.
  20694. @item @code{max-journal-usage} (default: @code{#f})
  20695. The maximum size for the journal on disk. @code{#f} does not set this option,
  20696. so the default value from Knot is used.
  20697. @item @code{max-journal-depth} (default: @code{#f})
  20698. The maximum size of the history. @code{#f} does not set this option, so the
  20699. default value from Knot is used.
  20700. @item @code{max-zone-size} (default: @code{#f})
  20701. The maximum size of the zone file. This limit is enforced for incoming
  20702. transfer and updates. @code{#f} does not set this option, so the default
  20703. value from Knot is used.
  20704. @item @code{dnssec-policy} (default: @code{#f})
  20705. A reference to a @code{knot-policy-configuration} record, or the special
  20706. name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
  20707. on this zone.
  20708. @item @code{serial-policy} (default: @code{'increment})
  20709. A policy between @code{'increment} and @code{'unixtime}.
  20710. @end table
  20711. @end deftp
  20712. @deftp {Data Type} knot-configuration
  20713. Data type representing the Knot configuration.
  20714. This type has the following parameters:
  20715. @table @asis
  20716. @item @code{knot} (default: @code{knot})
  20717. The Knot package.
  20718. @item @code{run-directory} (default: @code{"/var/run/knot"})
  20719. The run directory. This directory will be used for pid file and sockets.
  20720. @item @code{includes} (default: @code{'()})
  20721. A list of strings or file-like objects denoting other files that must be
  20722. included at the top of the configuration file.
  20723. @cindex secrets, Knot service
  20724. This can be used to manage secrets out-of-band. For example, secret
  20725. keys may be stored in an out-of-band file not managed by Guix, and
  20726. thus not visible in @file{/gnu/store}---e.g., you could store secret
  20727. key configuration in @file{/etc/knot/secrets.conf} and add this file
  20728. to the @code{includes} list.
  20729. One can generate a secret tsig key (for nsupdate and zone transfers with the
  20730. keymgr command from the knot package. Note that the package is not automatically
  20731. installed by the service. The following example shows how to generate a new
  20732. tsig key:
  20733. @example
  20734. keymgr -t mysecret > /etc/knot/secrets.conf
  20735. chmod 600 /etc/knot/secrets.conf
  20736. @end example
  20737. Also note that the generated key will be named @var{mysecret}, so it is the
  20738. name that needs to be used in the @var{key} field of the
  20739. @code{knot-acl-configuration} record and in other places that need to refer
  20740. to that key.
  20741. It can also be used to add configuration not supported by this interface.
  20742. @item @code{listen-v4} (default: @code{"0.0.0.0"})
  20743. An ip address on which to listen.
  20744. @item @code{listen-v6} (default: @code{"::"})
  20745. An ip address on which to listen.
  20746. @item @code{listen-port} (default: @code{53})
  20747. A port on which to listen.
  20748. @item @code{keys} (default: @code{'()})
  20749. The list of knot-key-configuration used by this configuration.
  20750. @item @code{acls} (default: @code{'()})
  20751. The list of knot-acl-configuration used by this configuration.
  20752. @item @code{remotes} (default: @code{'()})
  20753. The list of knot-remote-configuration used by this configuration.
  20754. @item @code{zones} (default: @code{'()})
  20755. The list of knot-zone-configuration used by this configuration.
  20756. @end table
  20757. @end deftp
  20758. @subsubheading Knot Resolver Service
  20759. @deffn {Scheme Variable} knot-resolver-service-type
  20760. This is the type of the knot resolver service, whose value should be
  20761. an @code{knot-resolver-configuration} object as in this example:
  20762. @lisp
  20763. (service knot-resolver-service-type
  20764. (knot-resolver-configuration
  20765. (kresd-config-file (plain-file "kresd.conf" "
  20766. net.listen('192.168.0.1', 5353)
  20767. user('knot-resolver', 'knot-resolver')
  20768. modules = @{ 'hints > iterate', 'stats', 'predict' @}
  20769. cache.size = 100 * MB
  20770. "))))
  20771. @end lisp
  20772. For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
  20773. @end deffn
  20774. @deftp {Data Type} knot-resolver-configuration
  20775. Data type representing the configuration of knot-resolver.
  20776. @table @asis
  20777. @item @code{package} (default: @var{knot-resolver})
  20778. Package object of the knot DNS resolver.
  20779. @item @code{kresd-config-file} (default: %kresd.conf)
  20780. File-like object of the kresd configuration file to use, by default it
  20781. will listen on @code{127.0.0.1} and @code{::1}.
  20782. @item @code{garbage-collection-interval} (default: 1000)
  20783. Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
  20784. @end table
  20785. @end deftp
  20786. @subsubheading Dnsmasq Service
  20787. @deffn {Scheme Variable} dnsmasq-service-type
  20788. This is the type of the dnsmasq service, whose value should be an
  20789. @code{dnsmasq-configuration} object as in this example:
  20790. @lisp
  20791. (service dnsmasq-service-type
  20792. (dnsmasq-configuration
  20793. (no-resolv? #t)
  20794. (servers '("192.168.1.1"))))
  20795. @end lisp
  20796. @end deffn
  20797. @deftp {Data Type} dnsmasq-configuration
  20798. Data type representing the configuration of dnsmasq.
  20799. @table @asis
  20800. @item @code{package} (default: @var{dnsmasq})
  20801. Package object of the dnsmasq server.
  20802. @item @code{no-hosts?} (default: @code{#f})
  20803. When true, don't read the hostnames in /etc/hosts.
  20804. @item @code{port} (default: @code{53})
  20805. The port to listen on. Setting this to zero completely disables DNS
  20806. responses, leaving only DHCP and/or TFTP functions.
  20807. @item @code{local-service?} (default: @code{#t})
  20808. Accept DNS queries only from hosts whose address is on a local subnet,
  20809. ie a subnet for which an interface exists on the server.
  20810. @item @code{listen-addresses} (default: @code{'()})
  20811. Listen on the given IP addresses.
  20812. @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
  20813. The file to read the IP address of the upstream nameservers from.
  20814. @item @code{no-resolv?} (default: @code{#f})
  20815. When true, don't read @var{resolv-file}.
  20816. @item @code{servers} (default: @code{'()})
  20817. Specify IP address of upstream servers directly.
  20818. @item @code{addresses} (default: @code{'()})
  20819. For each entry, specify an IP address to return for any host in the
  20820. given domains. Queries in the domains are never forwarded and always
  20821. replied to with the specified IP address.
  20822. This is useful for redirecting hosts locally, for example:
  20823. @lisp
  20824. (service dnsmasq-service-type
  20825. (dnsmasq-configuration
  20826. (addresses
  20827. '(; Redirect to a local web-server.
  20828. "/example.org/127.0.0.1"
  20829. ; Redirect subdomain to a specific IP.
  20830. "/subdomain.example.org/192.168.1.42"))))
  20831. @end lisp
  20832. Note that rules in @file{/etc/hosts} take precedence over this.
  20833. @item @code{cache-size} (default: @code{150})
  20834. Set the size of dnsmasq's cache. Setting the cache size to zero
  20835. disables caching.
  20836. @item @code{negative-cache?} (default: @code{#t})
  20837. When false, disable negative caching.
  20838. @item @code{tftp-enable?} (default: @code{#f})
  20839. Whether to enable the built-in TFTP server.
  20840. @item @code{tftp-no-fail?} (default: @code{#f})
  20841. If true, does not fail dnsmasq if the TFTP server could not start up.
  20842. @item @code{tftp-single-port?} (default: @code{#f})
  20843. Whether to use only one single port for TFTP.
  20844. @item @code{tftp-secure?} (default: @code{#f})
  20845. If true, only files owned by the user running the dnsmasq process are accessible.
  20846. If dnsmasq is being run as root, different rules apply:
  20847. @code{tftp-secure?} has no effect, but only files which have the
  20848. world-readable bit set are accessible.
  20849. @item @code{tftp-max} (default: @code{#f})
  20850. If set, sets the maximal number of concurrent connections allowed.
  20851. @item @code{tftp-mtu} (default: @code{#f})
  20852. If set, sets the MTU for TFTP packets to that value.
  20853. @item @code{tftp-no-blocksize?} (default: @code{#f})
  20854. If true, stops the TFTP server from negotiating the blocksize with a client.
  20855. @item @code{tftp-lowercase?} (default: @code{#f})
  20856. Whether to convert all filenames in TFTP requests to lowercase.
  20857. @item @code{tftp-port-range} (default: @code{#f})
  20858. If set, fixes the dynamical ports (one per client) to the given range
  20859. (@code{"<start>,<end>"}).
  20860. @item @code{tftp-root} (default: @code{/var/empty,lo})
  20861. Look for files to transfer using TFTP relative to the given directory.
  20862. When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
  20863. getting outside the specified root. Absolute paths (starting with @samp{/}) are
  20864. allowed, but they must be within the TFTP-root. If the optional interface
  20865. argument is given, the directory is only used for TFTP requests via that
  20866. interface.
  20867. @item @code{tftp-unique-root} (default: @code{#f})
  20868. If set, add the IP or hardware address of the TFTP client as a path component
  20869. on the end of the TFTP-root. Only valid if a TFTP root is set and the
  20870. directory exists. Defaults to adding IP address (in standard dotted-quad
  20871. format).
  20872. For instance, if @option{--tftp-root} is @samp{/tftp} and client
  20873. @samp{1.2.3.4} requests file @file{myfile} then the effective path will
  20874. be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
  20875. @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
  20876. append the MAC address instead, using lowercase zero padded digits
  20877. separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
  20878. resolving MAC addresses is only possible if the client is in the local
  20879. network or obtained a DHCP lease from dnsmasq.
  20880. @end table
  20881. @end deftp
  20882. @subsubheading ddclient Service
  20883. @cindex ddclient
  20884. The ddclient service described below runs the ddclient daemon, which takes
  20885. care of automatically updating DNS entries for service providers such as
  20886. @uref{https://dyn.com/dns/, Dyn}.
  20887. The following example show instantiates the service with its default
  20888. configuration:
  20889. @lisp
  20890. (service ddclient-service-type)
  20891. @end lisp
  20892. Note that ddclient needs to access credentials that are stored in a
  20893. @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
  20894. @code{secret-file} below). You are expected to create this file manually, in
  20895. an ``out-of-band'' fashion (you @emph{could} make this file part of the
  20896. service configuration, for instance by using @code{plain-file}, but it will be
  20897. world-readable @i{via} @file{/gnu/store}). See the examples in the
  20898. @file{share/ddclient} directory of the @code{ddclient} package.
  20899. @c %start of fragment
  20900. Available @code{ddclient-configuration} fields are:
  20901. @deftypevr {@code{ddclient-configuration} parameter} package ddclient
  20902. The ddclient package.
  20903. @end deftypevr
  20904. @deftypevr {@code{ddclient-configuration} parameter} integer daemon
  20905. The period after which ddclient will retry to check IP and domain name.
  20906. Defaults to @samp{300}.
  20907. @end deftypevr
  20908. @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
  20909. Use syslog for the output.
  20910. Defaults to @samp{#t}.
  20911. @end deftypevr
  20912. @deftypevr {@code{ddclient-configuration} parameter} string mail
  20913. Mail to user.
  20914. Defaults to @samp{"root"}.
  20915. @end deftypevr
  20916. @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
  20917. Mail failed update to user.
  20918. Defaults to @samp{"root"}.
  20919. @end deftypevr
  20920. @deftypevr {@code{ddclient-configuration} parameter} string pid
  20921. The ddclient PID file.
  20922. Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
  20923. @end deftypevr
  20924. @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
  20925. Enable SSL support.
  20926. Defaults to @samp{#t}.
  20927. @end deftypevr
  20928. @deftypevr {@code{ddclient-configuration} parameter} string user
  20929. Specifies the user name or ID that is used when running ddclient
  20930. program.
  20931. Defaults to @samp{"ddclient"}.
  20932. @end deftypevr
  20933. @deftypevr {@code{ddclient-configuration} parameter} string group
  20934. Group of the user who will run the ddclient program.
  20935. Defaults to @samp{"ddclient"}.
  20936. @end deftypevr
  20937. @deftypevr {@code{ddclient-configuration} parameter} string secret-file
  20938. Secret file which will be appended to @file{ddclient.conf} file. This
  20939. file contains credentials for use by ddclient. You are expected to
  20940. create it manually.
  20941. Defaults to @samp{"/etc/ddclient/secrets.conf"}.
  20942. @end deftypevr
  20943. @deftypevr {@code{ddclient-configuration} parameter} list extra-options
  20944. Extra options will be appended to @file{ddclient.conf} file.
  20945. Defaults to @samp{()}.
  20946. @end deftypevr
  20947. @c %end of fragment
  20948. @node VPN Services
  20949. @subsection VPN Services
  20950. @cindex VPN (virtual private network)
  20951. @cindex virtual private network (VPN)
  20952. The @code{(gnu services vpn)} module provides services related to
  20953. @dfn{virtual private networks} (VPNs).
  20954. @subsubheading OpenVPN
  20955. It provides a @emph{client} service for your machine to connect to a
  20956. VPN, and a @emph{server} service for your machine to host a VPN@.
  20957. @deffn {Scheme Procedure} openvpn-client-service @
  20958. [#:config (openvpn-client-configuration)]
  20959. Return a service that runs @command{openvpn}, a VPN daemon, as a client.
  20960. @end deffn
  20961. @deffn {Scheme Procedure} openvpn-server-service @
  20962. [#:config (openvpn-server-configuration)]
  20963. Return a service that runs @command{openvpn}, a VPN daemon, as a server.
  20964. Both can be run simultaneously.
  20965. @end deffn
  20966. @c %automatically generated documentation
  20967. Available @code{openvpn-client-configuration} fields are:
  20968. @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
  20969. The OpenVPN package.
  20970. @end deftypevr
  20971. @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
  20972. The OpenVPN pid file.
  20973. Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
  20974. @end deftypevr
  20975. @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
  20976. The protocol (UDP or TCP) used to open a channel between clients and
  20977. servers.
  20978. Defaults to @samp{udp}.
  20979. @end deftypevr
  20980. @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
  20981. The device type used to represent the VPN connection.
  20982. Defaults to @samp{tun}.
  20983. @end deftypevr
  20984. If you do not have some of these files (eg.@: you use a username and
  20985. password), you can disable any of the following three fields by setting
  20986. it to @code{'disabled}.
  20987. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
  20988. The certificate authority to check connections against.
  20989. Defaults to @samp{"/etc/openvpn/ca.crt"}.
  20990. @end deftypevr
  20991. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
  20992. The certificate of the machine the daemon is running on. It should be
  20993. signed by the authority given in @code{ca}.
  20994. Defaults to @samp{"/etc/openvpn/client.crt"}.
  20995. @end deftypevr
  20996. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
  20997. The key of the machine the daemon is running on. It must be the key whose
  20998. certificate is @code{cert}.
  20999. Defaults to @samp{"/etc/openvpn/client.key"}.
  21000. @end deftypevr
  21001. @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
  21002. Whether to use the lzo compression algorithm.
  21003. Defaults to @samp{#t}.
  21004. @end deftypevr
  21005. @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
  21006. Don't re-read key files across SIGUSR1 or --ping-restart.
  21007. Defaults to @samp{#t}.
  21008. @end deftypevr
  21009. @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
  21010. Don't close and reopen TUN/TAP device or run up/down scripts across
  21011. SIGUSR1 or --ping-restart restarts.
  21012. Defaults to @samp{#t}.
  21013. @end deftypevr
  21014. @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
  21015. (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
  21016. poll/epoll/select prior to the write operation.
  21017. Defaults to @samp{#f}.
  21018. @end deftypevr
  21019. @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
  21020. Verbosity level.
  21021. Defaults to @samp{3}.
  21022. @end deftypevr
  21023. @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
  21024. Add an additional layer of HMAC authentication on top of the TLS control
  21025. channel to protect against DoS attacks.
  21026. Defaults to @samp{#f}.
  21027. @end deftypevr
  21028. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
  21029. Authenticate with server using username/password. The option is a file
  21030. containing username/password on 2 lines. Do not use a file-like object as it
  21031. would be added to the store and readable by any user.
  21032. Defaults to @samp{'disabled}.
  21033. @end deftypevr
  21034. @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
  21035. Whether to check the server certificate has server usage extension.
  21036. Defaults to @samp{#t}.
  21037. @end deftypevr
  21038. @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
  21039. Bind to a specific local port number.
  21040. Defaults to @samp{#f}.
  21041. @end deftypevr
  21042. @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
  21043. Retry resolving server address.
  21044. Defaults to @samp{#t}.
  21045. @end deftypevr
  21046. @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
  21047. A list of remote servers to connect to.
  21048. Defaults to @samp{()}.
  21049. Available @code{openvpn-remote-configuration} fields are:
  21050. @deftypevr {@code{openvpn-remote-configuration} parameter} string name
  21051. Server name.
  21052. Defaults to @samp{"my-server"}.
  21053. @end deftypevr
  21054. @deftypevr {@code{openvpn-remote-configuration} parameter} number port
  21055. Port number the server listens to.
  21056. Defaults to @samp{1194}.
  21057. @end deftypevr
  21058. @end deftypevr
  21059. @c %end of automatic openvpn-client documentation
  21060. @c %automatically generated documentation
  21061. Available @code{openvpn-server-configuration} fields are:
  21062. @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
  21063. The OpenVPN package.
  21064. @end deftypevr
  21065. @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
  21066. The OpenVPN pid file.
  21067. Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
  21068. @end deftypevr
  21069. @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
  21070. The protocol (UDP or TCP) used to open a channel between clients and
  21071. servers.
  21072. Defaults to @samp{udp}.
  21073. @end deftypevr
  21074. @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
  21075. The device type used to represent the VPN connection.
  21076. Defaults to @samp{tun}.
  21077. @end deftypevr
  21078. If you do not have some of these files (eg.@: you use a username and
  21079. password), you can disable any of the following three fields by setting
  21080. it to @code{'disabled}.
  21081. @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
  21082. The certificate authority to check connections against.
  21083. Defaults to @samp{"/etc/openvpn/ca.crt"}.
  21084. @end deftypevr
  21085. @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
  21086. The certificate of the machine the daemon is running on. It should be
  21087. signed by the authority given in @code{ca}.
  21088. Defaults to @samp{"/etc/openvpn/client.crt"}.
  21089. @end deftypevr
  21090. @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
  21091. The key of the machine the daemon is running on. It must be the key whose
  21092. certificate is @code{cert}.
  21093. Defaults to @samp{"/etc/openvpn/client.key"}.
  21094. @end deftypevr
  21095. @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
  21096. Whether to use the lzo compression algorithm.
  21097. Defaults to @samp{#t}.
  21098. @end deftypevr
  21099. @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
  21100. Don't re-read key files across SIGUSR1 or --ping-restart.
  21101. Defaults to @samp{#t}.
  21102. @end deftypevr
  21103. @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
  21104. Don't close and reopen TUN/TAP device or run up/down scripts across
  21105. SIGUSR1 or --ping-restart restarts.
  21106. Defaults to @samp{#t}.
  21107. @end deftypevr
  21108. @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
  21109. (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
  21110. poll/epoll/select prior to the write operation.
  21111. Defaults to @samp{#f}.
  21112. @end deftypevr
  21113. @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
  21114. Verbosity level.
  21115. Defaults to @samp{3}.
  21116. @end deftypevr
  21117. @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
  21118. Add an additional layer of HMAC authentication on top of the TLS control
  21119. channel to protect against DoS attacks.
  21120. Defaults to @samp{#f}.
  21121. @end deftypevr
  21122. @deftypevr {@code{openvpn-server-configuration} parameter} number port
  21123. Specifies the port number on which the server listens.
  21124. Defaults to @samp{1194}.
  21125. @end deftypevr
  21126. @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
  21127. An ip and mask specifying the subnet inside the virtual network.
  21128. Defaults to @samp{"10.8.0.0 255.255.255.0"}.
  21129. @end deftypevr
  21130. @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
  21131. A CIDR notation specifying the IPv6 subnet inside the virtual network.
  21132. Defaults to @samp{#f}.
  21133. @end deftypevr
  21134. @deftypevr {@code{openvpn-server-configuration} parameter} string dh
  21135. The Diffie-Hellman parameters file.
  21136. Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
  21137. @end deftypevr
  21138. @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
  21139. The file that records client IPs.
  21140. Defaults to @samp{"/etc/openvpn/ipp.txt"}.
  21141. @end deftypevr
  21142. @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
  21143. When true, the server will act as a gateway for its clients.
  21144. Defaults to @samp{#f}.
  21145. @end deftypevr
  21146. @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
  21147. When true, clients are allowed to talk to each other inside the VPN.
  21148. Defaults to @samp{#f}.
  21149. @end deftypevr
  21150. @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
  21151. Causes ping-like messages to be sent back and forth over the link so
  21152. that each side knows when the other side has gone down. @code{keepalive}
  21153. requires a pair. The first element is the period of the ping sending,
  21154. and the second element is the timeout before considering the other side
  21155. down.
  21156. @end deftypevr
  21157. @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
  21158. The maximum number of clients.
  21159. Defaults to @samp{100}.
  21160. @end deftypevr
  21161. @deftypevr {@code{openvpn-server-configuration} parameter} string status
  21162. The status file. This file shows a small report on current connection.
  21163. It is truncated and rewritten every minute.
  21164. Defaults to @samp{"/var/run/openvpn/status"}.
  21165. @end deftypevr
  21166. @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
  21167. The list of configuration for some clients.
  21168. Defaults to @samp{()}.
  21169. Available @code{openvpn-ccd-configuration} fields are:
  21170. @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
  21171. Client name.
  21172. Defaults to @samp{"client"}.
  21173. @end deftypevr
  21174. @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
  21175. Client own network
  21176. Defaults to @samp{#f}.
  21177. @end deftypevr
  21178. @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
  21179. Client VPN IP.
  21180. Defaults to @samp{#f}.
  21181. @end deftypevr
  21182. @end deftypevr
  21183. @c %end of automatic openvpn-server documentation
  21184. @subsubheading Wireguard
  21185. @defvr {Scheme Variable} wireguard-service-type
  21186. A service type for a Wireguard tunnel interface. Its value must be a
  21187. @code{wireguard-configuration} record as in this example:
  21188. @lisp
  21189. (service wireguard-service-type
  21190. (wireguard-configuration
  21191. (peers
  21192. (list
  21193. (wireguard-peer
  21194. (name "my-peer")
  21195. (endpoint "my.wireguard.com:51820")
  21196. (public-key "hzpKg9X1yqu1axN6iJp0mWf6BZGo8m1wteKwtTmDGF4=")
  21197. (allowed-ips '("10.0.0.2/32")))))))
  21198. @end lisp
  21199. @end defvr
  21200. @deftp {Data Type} wireguard-configuration
  21201. Data type representing the configuration of the Wireguard service.
  21202. @table @asis
  21203. @item @code{wireguard}
  21204. The wireguard package to use for this service.
  21205. @item @code{interface} (default: @code{"wg0"})
  21206. The interface name for the VPN.
  21207. @item @code{addresses} (default: @code{'("10.0.0.1/32")})
  21208. The IP addresses to be assigned to the above interface.
  21209. @item @code{private-key} (default: @code{"/etc/wireguard/private.key"})
  21210. The private key file for the interface. It is automatically generated if
  21211. the file does not exist.
  21212. @item @code{peers} (default: @code{'()})
  21213. The authorized peers on this interface. This is a list of
  21214. @var{wireguard-peer} records.
  21215. @end table
  21216. @end deftp
  21217. @deftp {Data Type} wireguard-peer
  21218. Data type representing a Wireguard peer attached to a given interface.
  21219. @table @asis
  21220. @item @code{name}
  21221. The peer name.
  21222. @item @code{endpoint} (default: @code{#f})
  21223. The optional endpoint for the peer, such as
  21224. @code{"demo.wireguard.com:51820"}.
  21225. @item @code{public-key}
  21226. The peer public-key represented as a base64 string.
  21227. @item @code{allowed-ips}
  21228. A list of IP addresses from which incoming traffic for this peer is
  21229. allowed and to which incoming traffic for this peer is directed.
  21230. @end table
  21231. @end deftp
  21232. @node Network File System
  21233. @subsection Network File System
  21234. @cindex NFS
  21235. The @code{(gnu services nfs)} module provides the following services,
  21236. which are most commonly used in relation to mounting or exporting
  21237. directory trees as @dfn{network file systems} (NFS).
  21238. While it is possible to use the individual components that together make
  21239. up a Network File System service, we recommended to configure an NFS
  21240. server with the @code{nfs-service-type}.
  21241. @subsubheading NFS Service
  21242. @cindex NFS, server
  21243. The NFS service takes care of setting up all NFS component services,
  21244. kernel configuration file systems, and installs configuration files in
  21245. the locations that NFS expects.
  21246. @defvr {Scheme Variable} nfs-service-type
  21247. A service type for a complete NFS server.
  21248. @end defvr
  21249. @deftp {Data Type} nfs-configuration
  21250. This data type represents the configuration of the NFS service and all
  21251. of its subsystems.
  21252. It has the following parameters:
  21253. @table @asis
  21254. @item @code{nfs-utils} (default: @code{nfs-utils})
  21255. The nfs-utils package to use.
  21256. @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
  21257. If a list of string values is provided, the @command{rpc.nfsd} daemon
  21258. will be limited to supporting the given versions of the NFS protocol.
  21259. @item @code{exports} (default: @code{'()})
  21260. This is a list of directories the NFS server should export. Each entry
  21261. is a list consisting of two elements: a directory name and a string
  21262. containing all options. This is an example in which the directory
  21263. @file{/export} is served to all NFS clients as a read-only share:
  21264. @lisp
  21265. (nfs-configuration
  21266. (exports
  21267. '(("/export"
  21268. "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
  21269. @end lisp
  21270. @item @code{rpcmountd-port} (default: @code{#f})
  21271. The network port that the @command{rpc.mountd} daemon should use.
  21272. @item @code{rpcstatd-port} (default: @code{#f})
  21273. The network port that the @command{rpc.statd} daemon should use.
  21274. @item @code{rpcbind} (default: @code{rpcbind})
  21275. The rpcbind package to use.
  21276. @item @code{idmap-domain} (default: @code{"localdomain"})
  21277. The local NFSv4 domain name.
  21278. @item @code{nfsd-port} (default: @code{2049})
  21279. The network port that the @command{nfsd} daemon should use.
  21280. @item @code{nfsd-threads} (default: @code{8})
  21281. The number of threads used by the @command{nfsd} daemon.
  21282. @item @code{nfsd-tcp?} (default: @code{#t})
  21283. Whether the @command{nfsd} daemon should listen on a TCP socket.
  21284. @item @code{nfsd-udp?} (default: @code{#f})
  21285. Whether the @command{nfsd} daemon should listen on a UDP socket.
  21286. @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  21287. The directory where the pipefs file system is mounted.
  21288. @item @code{debug} (default: @code{'()"})
  21289. A list of subsystems for which debugging output should be enabled. This
  21290. is a list of symbols. Any of these symbols are valid: @code{nfsd},
  21291. @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
  21292. @end table
  21293. @end deftp
  21294. If you don't need a complete NFS service or prefer to build it yourself
  21295. you can use the individual component services that are documented below.
  21296. @subsubheading RPC Bind Service
  21297. @cindex rpcbind
  21298. The RPC Bind service provides a facility to map program numbers into
  21299. universal addresses.
  21300. Many NFS related services use this facility. Hence it is automatically
  21301. started when a dependent service starts.
  21302. @defvr {Scheme Variable} rpcbind-service-type
  21303. A service type for the RPC portmapper daemon.
  21304. @end defvr
  21305. @deftp {Data Type} rpcbind-configuration
  21306. Data type representing the configuration of the RPC Bind Service.
  21307. This type has the following parameters:
  21308. @table @asis
  21309. @item @code{rpcbind} (default: @code{rpcbind})
  21310. The rpcbind package to use.
  21311. @item @code{warm-start?} (default: @code{#t})
  21312. If this parameter is @code{#t}, then the daemon will read a
  21313. state file on startup thus reloading state information saved by a previous
  21314. instance.
  21315. @end table
  21316. @end deftp
  21317. @subsubheading Pipefs Pseudo File System
  21318. @cindex pipefs
  21319. @cindex rpc_pipefs
  21320. The pipefs file system is used to transfer NFS related data
  21321. between the kernel and user space programs.
  21322. @defvr {Scheme Variable} pipefs-service-type
  21323. A service type for the pipefs pseudo file system.
  21324. @end defvr
  21325. @deftp {Data Type} pipefs-configuration
  21326. Data type representing the configuration of the pipefs pseudo file system service.
  21327. This type has the following parameters:
  21328. @table @asis
  21329. @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  21330. The directory to which the file system is to be attached.
  21331. @end table
  21332. @end deftp
  21333. @subsubheading GSS Daemon Service
  21334. @cindex GSSD
  21335. @cindex GSS
  21336. @cindex global security system
  21337. The @dfn{global security system} (GSS) daemon provides strong security for RPC
  21338. based protocols.
  21339. Before exchanging RPC requests an RPC client must establish a security
  21340. context. Typically this is done using the Kerberos command @command{kinit}
  21341. or automatically at login time using PAM services (@pxref{Kerberos Services}).
  21342. @defvr {Scheme Variable} gss-service-type
  21343. A service type for the Global Security System (GSS) daemon.
  21344. @end defvr
  21345. @deftp {Data Type} gss-configuration
  21346. Data type representing the configuration of the GSS daemon service.
  21347. This type has the following parameters:
  21348. @table @asis
  21349. @item @code{nfs-utils} (default: @code{nfs-utils})
  21350. The package in which the @command{rpc.gssd} command is to be found.
  21351. @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  21352. The directory where the pipefs file system is mounted.
  21353. @end table
  21354. @end deftp
  21355. @subsubheading IDMAP Daemon Service
  21356. @cindex idmapd
  21357. @cindex name mapper
  21358. The idmap daemon service provides mapping between user IDs and user names.
  21359. Typically it is required in order to access file systems mounted via NFSv4.
  21360. @defvr {Scheme Variable} idmap-service-type
  21361. A service type for the Identity Mapper (IDMAP) daemon.
  21362. @end defvr
  21363. @deftp {Data Type} idmap-configuration
  21364. Data type representing the configuration of the IDMAP daemon service.
  21365. This type has the following parameters:
  21366. @table @asis
  21367. @item @code{nfs-utils} (default: @code{nfs-utils})
  21368. The package in which the @command{rpc.idmapd} command is to be found.
  21369. @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  21370. The directory where the pipefs file system is mounted.
  21371. @item @code{domain} (default: @code{#f})
  21372. The local NFSv4 domain name.
  21373. This must be a string or @code{#f}.
  21374. If it is @code{#f} then the daemon will use the host's fully qualified domain name.
  21375. @item @code{verbosity} (default: @code{0})
  21376. The verbosity level of the daemon.
  21377. @end table
  21378. @end deftp
  21379. @node Continuous Integration
  21380. @subsection Continuous Integration
  21381. @cindex continuous integration
  21382. @uref{https://guix.gnu.org/cuirass/, Cuirass} is a continuous
  21383. integration tool for Guix. It can be used both for development and for
  21384. providing substitutes to others (@pxref{Substitutes}).
  21385. The @code{(gnu services cuirass)} module provides the following service.
  21386. @defvr {Scheme Procedure} cuirass-service-type
  21387. The type of the Cuirass service. Its value must be a
  21388. @code{cuirass-configuration} object, as described below.
  21389. @end defvr
  21390. To add build jobs, you have to set the @code{specifications} field of
  21391. the configuration. For instance, the following example will build all
  21392. the packages provided by the @code{my-channel} channel.
  21393. @lisp
  21394. (define %cuirass-specs
  21395. #~(list (specification
  21396. (name "my-channel")
  21397. (build '(channels my-channel))
  21398. (channels
  21399. (cons (channel
  21400. (name 'my-channel)
  21401. (url "https://my-channel.git"))
  21402. %default-channels)))))
  21403. (service cuirass-service-type
  21404. (cuirass-configuration
  21405. (specifications %cuirass-specs)))
  21406. @end lisp
  21407. To build the @code{linux-libre} package defined by the default Guix
  21408. channel, one can use the following configuration.
  21409. @lisp
  21410. (define %cuirass-specs
  21411. #~(list (specification
  21412. (name "my-linux")
  21413. (build '(packages "linux-libre")))))
  21414. (service cuirass-service-type
  21415. (cuirass-configuration
  21416. (specifications %cuirass-specs)))
  21417. @end lisp
  21418. The other configuration possibilities, as well as the specification
  21419. record itself are described in the Cuirass manual
  21420. (@pxref{Specifications,,, cuirass, Cuirass}).
  21421. While information related to build jobs is located directly in the
  21422. specifications, global settings for the @command{cuirass} process are
  21423. accessible in other @code{cuirass-configuration} fields.
  21424. @deftp {Data Type} cuirass-configuration
  21425. Data type representing the configuration of Cuirass.
  21426. @table @asis
  21427. @item @code{cuirass} (default: @code{cuirass})
  21428. The Cuirass package to use.
  21429. @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
  21430. Location of the log file.
  21431. @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
  21432. Location of the log file used by the web interface.
  21433. @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
  21434. Location of the repository cache.
  21435. @item @code{user} (default: @code{"cuirass"})
  21436. Owner of the @code{cuirass} process.
  21437. @item @code{group} (default: @code{"cuirass"})
  21438. Owner's group of the @code{cuirass} process.
  21439. @item @code{interval} (default: @code{60})
  21440. Number of seconds between the poll of the repositories followed by the
  21441. Cuirass jobs.
  21442. @item @code{parameters} (default: @code{#f})
  21443. Read parameters from the given @var{parameters} file. The supported
  21444. parameters are described here (@pxref{Parameters,,, cuirass, Cuirass}).
  21445. @item @code{remote-server} (default: @code{#f})
  21446. A @code{cuirass-remote-server-configuration} record to use the build
  21447. remote mechanism or @code{#f} to use the default build mechanism.
  21448. @item @code{database} (default: @code{"dbname=cuirass host=/var/run/postgresql"})
  21449. Use @var{database} as the database containing the jobs and the past
  21450. build results. Since Cuirass uses PostgreSQL as a database engine,
  21451. @var{database} must be a string such as @code{"dbname=cuirass
  21452. host=localhost"}.
  21453. @item @code{port} (default: @code{8081})
  21454. Port number used by the HTTP server.
  21455. @item @code{host} (default: @code{"localhost"})
  21456. Listen on the network interface for @var{host}. The default is to
  21457. accept connections from localhost.
  21458. @item @code{specifications} (default: @code{#~'()})
  21459. A gexp (@pxref{G-Expressions}) that evaluates to a list of
  21460. specifications records. The specification record is described in the
  21461. Cuirass manual (@pxref{Specifications,,, cuirass, Cuirass}).
  21462. @item @code{use-substitutes?} (default: @code{#f})
  21463. This allows using substitutes to avoid building every dependencies of a job
  21464. from source.
  21465. @item @code{one-shot?} (default: @code{#f})
  21466. Only evaluate specifications and build derivations once.
  21467. @item @code{fallback?} (default: @code{#f})
  21468. When substituting a pre-built binary fails, fall back to building
  21469. packages locally.
  21470. @item @code{extra-options} (default: @code{'()})
  21471. Extra options to pass when running the Cuirass processes.
  21472. @end table
  21473. @end deftp
  21474. @cindex remote build
  21475. @subsubheading Cuirass remote building
  21476. Cuirass supports two mechanisms to build derivations.
  21477. @itemize
  21478. @item Using the local Guix daemon.
  21479. This is the default build mechanism. Once the build jobs are
  21480. evaluated, they are sent to the local Guix daemon. Cuirass then
  21481. listens to the Guix daemon output to detect the various build events.
  21482. @item Using the remote build mechanism.
  21483. The build jobs are not submitted to the local Guix daemon. Instead, a
  21484. remote server dispatches build requests to the connect remote workers,
  21485. according to the build priorities.
  21486. @end itemize
  21487. To enable this build mode a @code{cuirass-remote-server-configuration}
  21488. record must be passed as @code{remote-server} argument of the
  21489. @code{cuirass-configuration} record. The
  21490. @code{cuirass-remote-server-configuration} record is described below.
  21491. This build mode scales way better than the default build mode. This is
  21492. the build mode that is used on the GNU Guix build farm at
  21493. @url{https://ci.guix.gnu.org}. It should be preferred when using
  21494. Cuirass to build large amount of packages.
  21495. @deftp {Data Type} cuirass-remote-server-configuration
  21496. Data type representing the configuration of the Cuirass remote-server.
  21497. @table @asis
  21498. @item @code{backend-port} (default: @code{5555})
  21499. The TCP port for communicating with @code{remote-worker} processes
  21500. using ZMQ. It defaults to @code{5555}.
  21501. @item @code{log-port} (default: @code{5556})
  21502. The TCP port of the log server. It defaults to @code{5556}.
  21503. @item @code{publish-port} (default: @code{5557})
  21504. The TCP port of the publish server. It defaults to @code{5557}.
  21505. @item @code{log-file} (default: @code{"/var/log/cuirass-remote-server.log"})
  21506. Location of the log file.
  21507. @item @code{cache} (default: @code{"/var/cache/cuirass/remote"})
  21508. Use @var{cache} directory to cache build log files.
  21509. @item @code{trigger-url} (default: @code{#f})
  21510. Once a substitute is successfully fetched, trigger substitute baking at
  21511. @var{trigger-url}.
  21512. @item @code{public-key}
  21513. @item @code{private-key}
  21514. Use the specific @var{file}s as the public/private key pair used to sign
  21515. the store items being published.
  21516. @end table
  21517. @end deftp
  21518. At least one remote worker must also be started on any machine of the
  21519. local network to actually perform the builds and report their status.
  21520. @deftp {Data Type} cuirass-remote-worker-configuration
  21521. Data type representing the configuration of the Cuirass remote-worker.
  21522. @table @asis
  21523. @item @code{cuirass} (default: @code{cuirass})
  21524. The Cuirass package to use.
  21525. @item @code{workers} (default: @code{1})
  21526. Start @var{workers} parallel workers.
  21527. @item @code{server} (default: @code{#f})
  21528. Do not use Avahi discovery and connect to the given @code{server} IP
  21529. address instead.
  21530. @item @code{systems} (default: @code{(list (%current-system))})
  21531. Only request builds for the given @var{systems}.
  21532. @item @code{log-file} (default: @code{"/var/log/cuirass-remote-worker.log"})
  21533. Location of the log file.
  21534. @item @code{publish-port} (default: @code{5558})
  21535. The TCP port of the publish server. It defaults to @code{5558}.
  21536. @item @code{public-key}
  21537. @item @code{private-key}
  21538. Use the specific @var{file}s as the public/private key pair used to sign
  21539. the store items being published.
  21540. @end table
  21541. @end deftp
  21542. @node Power Management Services
  21543. @subsection Power Management Services
  21544. @cindex tlp
  21545. @cindex power management with TLP
  21546. @subsubheading TLP daemon
  21547. The @code{(gnu services pm)} module provides a Guix service definition
  21548. for the Linux power management tool TLP.
  21549. TLP enables various powersaving modes in userspace and kernel.
  21550. Contrary to @code{upower-service}, it is not a passive,
  21551. monitoring tool, as it will apply custom settings each time a new power
  21552. source is detected. More information can be found at
  21553. @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
  21554. @deffn {Scheme Variable} tlp-service-type
  21555. The service type for the TLP tool. The default settings are optimised
  21556. for battery life on most systems, but you can tweak them to your heart's
  21557. content by adding a valid @code{tlp-configuration}:
  21558. @lisp
  21559. (service tlp-service-type
  21560. (tlp-configuration
  21561. (cpu-scaling-governor-on-ac (list "performance"))
  21562. (sched-powersave-on-bat? #t)))
  21563. @end lisp
  21564. @end deffn
  21565. Each parameter definition is preceded by its type; for example,
  21566. @samp{boolean foo} indicates that the @code{foo} parameter
  21567. should be specified as a boolean. Types starting with
  21568. @code{maybe-} denote parameters that won't show up in TLP config file
  21569. when their value is @code{'disabled}.
  21570. @c The following documentation was initially generated by
  21571. @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
  21572. @c documentation is better, so we shouldn't hesitate to edit below as
  21573. @c needed. However if the change you want to make to this documentation
  21574. @c can be done in an automated way, it's probably easier to change
  21575. @c (generate-documentation) than to make it below and have to deal with
  21576. @c the churn as TLP updates.
  21577. Available @code{tlp-configuration} fields are:
  21578. @deftypevr {@code{tlp-configuration} parameter} package tlp
  21579. The TLP package.
  21580. @end deftypevr
  21581. @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
  21582. Set to true if you wish to enable TLP.
  21583. Defaults to @samp{#t}.
  21584. @end deftypevr
  21585. @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
  21586. Default mode when no power supply can be detected. Alternatives are AC
  21587. and BAT.
  21588. Defaults to @samp{"AC"}.
  21589. @end deftypevr
  21590. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
  21591. Number of seconds Linux kernel has to wait after the disk goes idle,
  21592. before syncing on AC.
  21593. Defaults to @samp{0}.
  21594. @end deftypevr
  21595. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
  21596. Same as @code{disk-idle-ac} but on BAT mode.
  21597. Defaults to @samp{2}.
  21598. @end deftypevr
  21599. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
  21600. Dirty pages flushing periodicity, expressed in seconds.
  21601. Defaults to @samp{15}.
  21602. @end deftypevr
  21603. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
  21604. Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
  21605. Defaults to @samp{60}.
  21606. @end deftypevr
  21607. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
  21608. CPU frequency scaling governor on AC mode. With intel_pstate driver,
  21609. alternatives are powersave and performance. With acpi-cpufreq driver,
  21610. alternatives are ondemand, powersave, performance and conservative.
  21611. Defaults to @samp{disabled}.
  21612. @end deftypevr
  21613. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
  21614. Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
  21615. Defaults to @samp{disabled}.
  21616. @end deftypevr
  21617. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
  21618. Set the min available frequency for the scaling governor on AC.
  21619. Defaults to @samp{disabled}.
  21620. @end deftypevr
  21621. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
  21622. Set the max available frequency for the scaling governor on AC.
  21623. Defaults to @samp{disabled}.
  21624. @end deftypevr
  21625. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
  21626. Set the min available frequency for the scaling governor on BAT.
  21627. Defaults to @samp{disabled}.
  21628. @end deftypevr
  21629. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
  21630. Set the max available frequency for the scaling governor on BAT.
  21631. Defaults to @samp{disabled}.
  21632. @end deftypevr
  21633. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
  21634. Limit the min P-state to control the power dissipation of the CPU, in AC
  21635. mode. Values are stated as a percentage of the available performance.
  21636. Defaults to @samp{disabled}.
  21637. @end deftypevr
  21638. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
  21639. Limit the max P-state to control the power dissipation of the CPU, in AC
  21640. mode. Values are stated as a percentage of the available performance.
  21641. Defaults to @samp{disabled}.
  21642. @end deftypevr
  21643. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
  21644. Same as @code{cpu-min-perf-on-ac} on BAT mode.
  21645. Defaults to @samp{disabled}.
  21646. @end deftypevr
  21647. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
  21648. Same as @code{cpu-max-perf-on-ac} on BAT mode.
  21649. Defaults to @samp{disabled}.
  21650. @end deftypevr
  21651. @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
  21652. Enable CPU turbo boost feature on AC mode.
  21653. Defaults to @samp{disabled}.
  21654. @end deftypevr
  21655. @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
  21656. Same as @code{cpu-boost-on-ac?} on BAT mode.
  21657. Defaults to @samp{disabled}.
  21658. @end deftypevr
  21659. @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
  21660. Allow Linux kernel to minimize the number of CPU cores/hyper-threads
  21661. used under light load conditions.
  21662. Defaults to @samp{#f}.
  21663. @end deftypevr
  21664. @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
  21665. Same as @code{sched-powersave-on-ac?} but on BAT mode.
  21666. Defaults to @samp{#t}.
  21667. @end deftypevr
  21668. @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
  21669. Enable Linux kernel NMI watchdog.
  21670. Defaults to @samp{#f}.
  21671. @end deftypevr
  21672. @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
  21673. For Linux kernels with PHC patch applied, change CPU voltages. An
  21674. example value would be @samp{"F:V F:V F:V F:V"}.
  21675. Defaults to @samp{disabled}.
  21676. @end deftypevr
  21677. @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
  21678. Set CPU performance versus energy saving policy on AC@. Alternatives are
  21679. performance, normal, powersave.
  21680. Defaults to @samp{"performance"}.
  21681. @end deftypevr
  21682. @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
  21683. Same as @code{energy-perf-policy-ac} but on BAT mode.
  21684. Defaults to @samp{"powersave"}.
  21685. @end deftypevr
  21686. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
  21687. Hard disk devices.
  21688. @end deftypevr
  21689. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
  21690. Hard disk advanced power management level.
  21691. @end deftypevr
  21692. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
  21693. Same as @code{disk-apm-bat} but on BAT mode.
  21694. @end deftypevr
  21695. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
  21696. Hard disk spin down timeout. One value has to be specified for each
  21697. declared hard disk.
  21698. Defaults to @samp{disabled}.
  21699. @end deftypevr
  21700. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
  21701. Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
  21702. Defaults to @samp{disabled}.
  21703. @end deftypevr
  21704. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
  21705. Select IO scheduler for disk devices. One value has to be specified for
  21706. each declared hard disk. Example alternatives are cfq, deadline and
  21707. noop.
  21708. Defaults to @samp{disabled}.
  21709. @end deftypevr
  21710. @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
  21711. SATA aggressive link power management (ALPM) level. Alternatives are
  21712. min_power, medium_power, max_performance.
  21713. Defaults to @samp{"max_performance"}.
  21714. @end deftypevr
  21715. @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
  21716. Same as @code{sata-linkpwr-ac} but on BAT mode.
  21717. Defaults to @samp{"min_power"}.
  21718. @end deftypevr
  21719. @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
  21720. Exclude specified SATA host devices for link power management.
  21721. Defaults to @samp{disabled}.
  21722. @end deftypevr
  21723. @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
  21724. Enable Runtime Power Management for AHCI controller and disks on AC
  21725. mode.
  21726. Defaults to @samp{disabled}.
  21727. @end deftypevr
  21728. @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
  21729. Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
  21730. Defaults to @samp{disabled}.
  21731. @end deftypevr
  21732. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
  21733. Seconds of inactivity before disk is suspended.
  21734. Defaults to @samp{15}.
  21735. @end deftypevr
  21736. @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
  21737. PCI Express Active State Power Management level. Alternatives are
  21738. default, performance, powersave.
  21739. Defaults to @samp{"performance"}.
  21740. @end deftypevr
  21741. @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
  21742. Same as @code{pcie-aspm-ac} but on BAT mode.
  21743. Defaults to @samp{"powersave"}.
  21744. @end deftypevr
  21745. @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
  21746. Radeon graphics clock speed level. Alternatives are low, mid, high,
  21747. auto, default.
  21748. Defaults to @samp{"high"}.
  21749. @end deftypevr
  21750. @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
  21751. Same as @code{radeon-power-ac} but on BAT mode.
  21752. Defaults to @samp{"low"}.
  21753. @end deftypevr
  21754. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
  21755. Radeon dynamic power management method (DPM). Alternatives are battery,
  21756. performance.
  21757. Defaults to @samp{"performance"}.
  21758. @end deftypevr
  21759. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
  21760. Same as @code{radeon-dpm-state-ac} but on BAT mode.
  21761. Defaults to @samp{"battery"}.
  21762. @end deftypevr
  21763. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
  21764. Radeon DPM performance level. Alternatives are auto, low, high.
  21765. Defaults to @samp{"auto"}.
  21766. @end deftypevr
  21767. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
  21768. Same as @code{radeon-dpm-perf-ac} but on BAT mode.
  21769. Defaults to @samp{"auto"}.
  21770. @end deftypevr
  21771. @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
  21772. Wifi power saving mode.
  21773. Defaults to @samp{#f}.
  21774. @end deftypevr
  21775. @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
  21776. Same as @code{wifi-power-ac?} but on BAT mode.
  21777. Defaults to @samp{#t}.
  21778. @end deftypevr
  21779. @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
  21780. Disable wake on LAN.
  21781. Defaults to @samp{#t}.
  21782. @end deftypevr
  21783. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
  21784. Timeout duration in seconds before activating audio power saving on
  21785. Intel HDA and AC97 devices. A value of 0 disables power saving.
  21786. Defaults to @samp{0}.
  21787. @end deftypevr
  21788. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
  21789. Same as @code{sound-powersave-ac} but on BAT mode.
  21790. Defaults to @samp{1}.
  21791. @end deftypevr
  21792. @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
  21793. Disable controller in powersaving mode on Intel HDA devices.
  21794. Defaults to @samp{#t}.
  21795. @end deftypevr
  21796. @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
  21797. Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
  21798. powered on again by releasing (and reinserting) the eject lever or by
  21799. pressing the disc eject button on newer models.
  21800. Defaults to @samp{#f}.
  21801. @end deftypevr
  21802. @deftypevr {@code{tlp-configuration} parameter} string bay-device
  21803. Name of the optical drive device to power off.
  21804. Defaults to @samp{"sr0"}.
  21805. @end deftypevr
  21806. @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
  21807. Runtime Power Management for PCI(e) bus devices. Alternatives are on
  21808. and auto.
  21809. Defaults to @samp{"on"}.
  21810. @end deftypevr
  21811. @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
  21812. Same as @code{runtime-pm-ac} but on BAT mode.
  21813. Defaults to @samp{"auto"}.
  21814. @end deftypevr
  21815. @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
  21816. Runtime Power Management for all PCI(e) bus devices, except blacklisted
  21817. ones.
  21818. Defaults to @samp{#t}.
  21819. @end deftypevr
  21820. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
  21821. Exclude specified PCI(e) device addresses from Runtime Power Management.
  21822. Defaults to @samp{disabled}.
  21823. @end deftypevr
  21824. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
  21825. Exclude PCI(e) devices assigned to the specified drivers from Runtime
  21826. Power Management.
  21827. @end deftypevr
  21828. @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
  21829. Enable USB autosuspend feature.
  21830. Defaults to @samp{#t}.
  21831. @end deftypevr
  21832. @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
  21833. Exclude specified devices from USB autosuspend.
  21834. Defaults to @samp{disabled}.
  21835. @end deftypevr
  21836. @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
  21837. Exclude WWAN devices from USB autosuspend.
  21838. Defaults to @samp{#t}.
  21839. @end deftypevr
  21840. @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
  21841. Include specified devices into USB autosuspend, even if they are already
  21842. excluded by the driver or via @code{usb-blacklist-wwan?}.
  21843. Defaults to @samp{disabled}.
  21844. @end deftypevr
  21845. @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
  21846. Enable USB autosuspend before shutdown.
  21847. Defaults to @samp{disabled}.
  21848. @end deftypevr
  21849. @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
  21850. Restore radio device state (bluetooth, wifi, wwan) from previous
  21851. shutdown on system startup.
  21852. Defaults to @samp{#f}.
  21853. @end deftypevr
  21854. @cindex thermald
  21855. @cindex CPU frequency scaling with thermald
  21856. @subsubheading Thermald daemon
  21857. The @code{(gnu services pm)} module provides an interface to
  21858. thermald, a CPU frequency scaling service which helps prevent overheating.
  21859. @defvr {Scheme Variable} thermald-service-type
  21860. This is the service type for
  21861. @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
  21862. Thermal Daemon, which is responsible for controlling the thermal state
  21863. of processors and preventing overheating.
  21864. @end defvr
  21865. @deftp {Data Type} thermald-configuration
  21866. Data type representing the configuration of @code{thermald-service-type}.
  21867. @table @asis
  21868. @item @code{ignore-cpuid-check?} (default: @code{#f})
  21869. Ignore cpuid check for supported CPU models.
  21870. @item @code{thermald} (default: @var{thermald})
  21871. Package object of thermald.
  21872. @end table
  21873. @end deftp
  21874. @node Audio Services
  21875. @subsection Audio Services
  21876. The @code{(gnu services audio)} module provides a service to start MPD
  21877. (the Music Player Daemon).
  21878. @cindex mpd
  21879. @subsubheading Music Player Daemon
  21880. The Music Player Daemon (MPD) is a service that can play music while
  21881. being controlled from the local machine or over the network by a variety
  21882. of clients.
  21883. The following example shows how one might run @code{mpd} as user
  21884. @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
  21885. @lisp
  21886. (service mpd-service-type
  21887. (mpd-configuration
  21888. (user "bob")
  21889. (port "6666")))
  21890. @end lisp
  21891. @defvr {Scheme Variable} mpd-service-type
  21892. The service type for @command{mpd}
  21893. @end defvr
  21894. @deftp {Data Type} mpd-configuration
  21895. Data type representing the configuration of @command{mpd}.
  21896. @table @asis
  21897. @item @code{user} (default: @code{"mpd"})
  21898. The user to run mpd as.
  21899. @item @code{music-dir} (default: @code{"~/Music"})
  21900. The directory to scan for music files.
  21901. @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
  21902. The directory to store playlists.
  21903. @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
  21904. The location of the music database.
  21905. @item @code{state-file} (default: @code{"~/.mpd/state"})
  21906. The location of the file that stores current MPD's state.
  21907. @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
  21908. The location of the sticker database.
  21909. @item @code{port} (default: @code{"6600"})
  21910. The port to run mpd on.
  21911. @item @code{address} (default: @code{"any"})
  21912. The address that mpd will bind to. To use a Unix domain socket,
  21913. an absolute path can be specified here.
  21914. @item @code{outputs} (default: @code{"(list (mpd-output))"})
  21915. The audio outputs that MPD can use. By default this is a single output using pulseaudio.
  21916. @end table
  21917. @end deftp
  21918. @deftp {Data Type} mpd-output
  21919. Data type representing an @command{mpd} audio output.
  21920. @table @asis
  21921. @item @code{name} (default: @code{"MPD"})
  21922. The name of the audio output.
  21923. @item @code{type} (default: @code{"pulse"})
  21924. The type of audio output.
  21925. @item @code{enabled?} (default: @code{#t})
  21926. Specifies whether this audio output is enabled when MPD is started. By
  21927. default, all audio outputs are enabled. This is just the default
  21928. setting when there is no state file; with a state file, the previous
  21929. state is restored.
  21930. @item @code{tags?} (default: @code{#t})
  21931. If set to @code{#f}, then MPD will not send tags to this output. This
  21932. is only useful for output plugins that can receive tags, for example the
  21933. @code{httpd} output plugin.
  21934. @item @code{always-on?} (default: @code{#f})
  21935. If set to @code{#t}, then MPD attempts to keep this audio output always
  21936. open. This may be useful for streaming servers, when you don’t want to
  21937. disconnect all listeners even when playback is accidentally stopped.
  21938. @item @code{mixer-type}
  21939. This field accepts a symbol that specifies which mixer should be used
  21940. for this audio output: the @code{hardware} mixer, the @code{software}
  21941. mixer, the @code{null} mixer (allows setting the volume, but with no
  21942. effect; this can be used as a trick to implement an external mixer
  21943. External Mixer) or no mixer (@code{none}).
  21944. @item @code{extra-options} (default: @code{'()})
  21945. An association list of option symbols to string values to be appended to
  21946. the audio output configuration.
  21947. @end table
  21948. @end deftp
  21949. The following example shows a configuration of @code{mpd} that provides
  21950. an HTTP audio streaming output.
  21951. @lisp
  21952. (service mpd-service-type
  21953. (mpd-configuration
  21954. (outputs
  21955. (list (mpd-output
  21956. (name "streaming")
  21957. (type "httpd")
  21958. (mixer-type 'null)
  21959. (extra-options
  21960. `((encoder . "vorbis")
  21961. (port . "8080"))))))))
  21962. @end lisp
  21963. @node Virtualization Services
  21964. @subsection Virtualization Services
  21965. The @code{(gnu services virtualization)} module provides services for
  21966. the libvirt and virtlog daemons, as well as other virtualization-related
  21967. services.
  21968. @subsubheading Libvirt daemon
  21969. @code{libvirtd} is the server side daemon component of the libvirt
  21970. virtualization management system. This daemon runs on host servers
  21971. and performs required management tasks for virtualized guests.
  21972. @deffn {Scheme Variable} libvirt-service-type
  21973. This is the type of the @uref{https://libvirt.org, libvirt daemon}.
  21974. Its value must be a @code{libvirt-configuration}.
  21975. @lisp
  21976. (service libvirt-service-type
  21977. (libvirt-configuration
  21978. (unix-sock-group "libvirt")
  21979. (tls-port "16555")))
  21980. @end lisp
  21981. @end deffn
  21982. @c Auto-generated with (generate-libvirt-documentation)
  21983. Available @code{libvirt-configuration} fields are:
  21984. @deftypevr {@code{libvirt-configuration} parameter} package libvirt
  21985. Libvirt package.
  21986. @end deftypevr
  21987. @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
  21988. Flag listening for secure TLS connections on the public TCP/IP port.
  21989. You must set @code{listen} for this to have any effect.
  21990. It is necessary to setup a CA and issue server certificates before using
  21991. this capability.
  21992. Defaults to @samp{#t}.
  21993. @end deftypevr
  21994. @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
  21995. Listen for unencrypted TCP connections on the public TCP/IP port. You must
  21996. set @code{listen} for this to have any effect.
  21997. Using the TCP socket requires SASL authentication by default. Only SASL
  21998. mechanisms which support data encryption are allowed. This is
  21999. DIGEST_MD5 and GSSAPI (Kerberos5).
  22000. Defaults to @samp{#f}.
  22001. @end deftypevr
  22002. @deftypevr {@code{libvirt-configuration} parameter} string tls-port
  22003. Port for accepting secure TLS connections. This can be a port number,
  22004. or service name.
  22005. Defaults to @samp{"16514"}.
  22006. @end deftypevr
  22007. @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
  22008. Port for accepting insecure TCP connections. This can be a port number,
  22009. or service name.
  22010. Defaults to @samp{"16509"}.
  22011. @end deftypevr
  22012. @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
  22013. IP address or hostname used for client connections.
  22014. Defaults to @samp{"0.0.0.0"}.
  22015. @end deftypevr
  22016. @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
  22017. Flag toggling mDNS advertisement of the libvirt service.
  22018. Alternatively can disable for all services on a host by stopping the
  22019. Avahi daemon.
  22020. Defaults to @samp{#f}.
  22021. @end deftypevr
  22022. @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
  22023. Default mDNS advertisement name. This must be unique on the immediate
  22024. broadcast network.
  22025. Defaults to @samp{"Virtualization Host <hostname>"}.
  22026. @end deftypevr
  22027. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
  22028. UNIX domain socket group ownership. This can be used to allow a
  22029. 'trusted' set of users access to management capabilities without
  22030. becoming root.
  22031. Defaults to @samp{"root"}.
  22032. @end deftypevr
  22033. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
  22034. UNIX socket permissions for the R/O socket. This is used for monitoring
  22035. VM status only.
  22036. Defaults to @samp{"0777"}.
  22037. @end deftypevr
  22038. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
  22039. UNIX socket permissions for the R/W socket. Default allows only root.
  22040. If PolicyKit is enabled on the socket, the default will change to allow
  22041. everyone (eg, 0777)
  22042. Defaults to @samp{"0770"}.
  22043. @end deftypevr
  22044. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
  22045. UNIX socket permissions for the admin socket. Default allows only owner
  22046. (root), do not change it unless you are sure to whom you are exposing
  22047. the access to.
  22048. Defaults to @samp{"0777"}.
  22049. @end deftypevr
  22050. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
  22051. The directory in which sockets will be found/created.
  22052. Defaults to @samp{"/var/run/libvirt"}.
  22053. @end deftypevr
  22054. @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
  22055. Authentication scheme for UNIX read-only sockets. By default socket
  22056. permissions allow anyone to connect
  22057. Defaults to @samp{"polkit"}.
  22058. @end deftypevr
  22059. @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
  22060. Authentication scheme for UNIX read-write sockets. By default socket
  22061. permissions only allow root. If PolicyKit support was compiled into
  22062. libvirt, the default will be to use 'polkit' auth.
  22063. Defaults to @samp{"polkit"}.
  22064. @end deftypevr
  22065. @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
  22066. Authentication scheme for TCP sockets. If you don't enable SASL, then
  22067. all TCP traffic is cleartext. Don't do this outside of a dev/test
  22068. scenario.
  22069. Defaults to @samp{"sasl"}.
  22070. @end deftypevr
  22071. @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
  22072. Authentication scheme for TLS sockets. TLS sockets already have
  22073. encryption provided by the TLS layer, and limited authentication is done
  22074. by certificates.
  22075. It is possible to make use of any SASL authentication mechanism as well,
  22076. by using 'sasl' for this option
  22077. Defaults to @samp{"none"}.
  22078. @end deftypevr
  22079. @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
  22080. API access control scheme.
  22081. By default an authenticated user is allowed access to all APIs. Access
  22082. drivers can place restrictions on this.
  22083. Defaults to @samp{()}.
  22084. @end deftypevr
  22085. @deftypevr {@code{libvirt-configuration} parameter} string key-file
  22086. Server key file path. If set to an empty string, then no private key is
  22087. loaded.
  22088. Defaults to @samp{""}.
  22089. @end deftypevr
  22090. @deftypevr {@code{libvirt-configuration} parameter} string cert-file
  22091. Server key file path. If set to an empty string, then no certificate is
  22092. loaded.
  22093. Defaults to @samp{""}.
  22094. @end deftypevr
  22095. @deftypevr {@code{libvirt-configuration} parameter} string ca-file
  22096. Server key file path. If set to an empty string, then no CA certificate
  22097. is loaded.
  22098. Defaults to @samp{""}.
  22099. @end deftypevr
  22100. @deftypevr {@code{libvirt-configuration} parameter} string crl-file
  22101. Certificate revocation list path. If set to an empty string, then no
  22102. CRL is loaded.
  22103. Defaults to @samp{""}.
  22104. @end deftypevr
  22105. @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
  22106. Disable verification of our own server certificates.
  22107. When libvirtd starts it performs some sanity checks against its own
  22108. certificates.
  22109. Defaults to @samp{#f}.
  22110. @end deftypevr
  22111. @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
  22112. Disable verification of client certificates.
  22113. Client certificate verification is the primary authentication mechanism.
  22114. Any client which does not present a certificate signed by the CA will be
  22115. rejected.
  22116. Defaults to @samp{#f}.
  22117. @end deftypevr
  22118. @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
  22119. Whitelist of allowed x509 Distinguished Name.
  22120. Defaults to @samp{()}.
  22121. @end deftypevr
  22122. @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
  22123. Whitelist of allowed SASL usernames. The format for username depends on
  22124. the SASL authentication mechanism.
  22125. Defaults to @samp{()}.
  22126. @end deftypevr
  22127. @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
  22128. Override the compile time default TLS priority string. The default is
  22129. usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
  22130. is desired for libvirt to deviate from the global default settings.
  22131. Defaults to @samp{"NORMAL"}.
  22132. @end deftypevr
  22133. @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
  22134. Maximum number of concurrent client connections to allow over all
  22135. sockets combined.
  22136. Defaults to @samp{5000}.
  22137. @end deftypevr
  22138. @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
  22139. Maximum length of queue of connections waiting to be accepted by the
  22140. daemon. Note, that some protocols supporting retransmission may obey
  22141. this so that a later reattempt at connection succeeds.
  22142. Defaults to @samp{1000}.
  22143. @end deftypevr
  22144. @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
  22145. Maximum length of queue of accepted but not yet authenticated clients.
  22146. Set this to zero to turn this feature off
  22147. Defaults to @samp{20}.
  22148. @end deftypevr
  22149. @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
  22150. Number of workers to start up initially.
  22151. Defaults to @samp{5}.
  22152. @end deftypevr
  22153. @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
  22154. Maximum number of worker threads.
  22155. If the number of active clients exceeds @code{min-workers}, then more
  22156. threads are spawned, up to max_workers limit. Typically you'd want
  22157. max_workers to equal maximum number of clients allowed.
  22158. Defaults to @samp{20}.
  22159. @end deftypevr
  22160. @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
  22161. Number of priority workers. If all workers from above pool are stuck,
  22162. some calls marked as high priority (notably domainDestroy) can be
  22163. executed in this pool.
  22164. Defaults to @samp{5}.
  22165. @end deftypevr
  22166. @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
  22167. Total global limit on concurrent RPC calls.
  22168. Defaults to @samp{20}.
  22169. @end deftypevr
  22170. @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
  22171. Limit on concurrent requests from a single client connection. To avoid
  22172. one client monopolizing the server this should be a small fraction of
  22173. the global max_requests and max_workers parameter.
  22174. Defaults to @samp{5}.
  22175. @end deftypevr
  22176. @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
  22177. Same as @code{min-workers} but for the admin interface.
  22178. Defaults to @samp{1}.
  22179. @end deftypevr
  22180. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
  22181. Same as @code{max-workers} but for the admin interface.
  22182. Defaults to @samp{5}.
  22183. @end deftypevr
  22184. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
  22185. Same as @code{max-clients} but for the admin interface.
  22186. Defaults to @samp{5}.
  22187. @end deftypevr
  22188. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
  22189. Same as @code{max-queued-clients} but for the admin interface.
  22190. Defaults to @samp{5}.
  22191. @end deftypevr
  22192. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
  22193. Same as @code{max-client-requests} but for the admin interface.
  22194. Defaults to @samp{5}.
  22195. @end deftypevr
  22196. @deftypevr {@code{libvirt-configuration} parameter} integer log-level
  22197. Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
  22198. Defaults to @samp{3}.
  22199. @end deftypevr
  22200. @deftypevr {@code{libvirt-configuration} parameter} string log-filters
  22201. Logging filters.
  22202. A filter allows to select a different logging level for a given category
  22203. of logs. The format for a filter is one of:
  22204. @itemize @bullet
  22205. @item
  22206. x:name
  22207. @item
  22208. x:+name
  22209. @end itemize
  22210. where @code{name} is a string which is matched against the category
  22211. given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
  22212. file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
  22213. name in the filter can be a substring of the full category name, in
  22214. order to match multiple similar categories), the optional @samp{"+"}
  22215. prefix tells libvirt to log stack trace for each message matching name,
  22216. and @code{x} is the minimal level where matching messages should be
  22217. logged:
  22218. @itemize @bullet
  22219. @item
  22220. 1: DEBUG
  22221. @item
  22222. 2: INFO
  22223. @item
  22224. 3: WARNING
  22225. @item
  22226. 4: ERROR
  22227. @end itemize
  22228. Multiple filters can be defined in a single filters statement, they just
  22229. need to be separated by spaces.
  22230. Defaults to @samp{"3:remote 4:event"}.
  22231. @end deftypevr
  22232. @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
  22233. Logging outputs.
  22234. An output is one of the places to save logging information. The format
  22235. for an output can be:
  22236. @table @code
  22237. @item x:stderr
  22238. output goes to stderr
  22239. @item x:syslog:name
  22240. use syslog for the output and use the given name as the ident
  22241. @item x:file:file_path
  22242. output to a file, with the given filepath
  22243. @item x:journald
  22244. output to journald logging system
  22245. @end table
  22246. In all case the x prefix is the minimal level, acting as a filter
  22247. @itemize @bullet
  22248. @item
  22249. 1: DEBUG
  22250. @item
  22251. 2: INFO
  22252. @item
  22253. 3: WARNING
  22254. @item
  22255. 4: ERROR
  22256. @end itemize
  22257. Multiple outputs can be defined, they just need to be separated by
  22258. spaces.
  22259. Defaults to @samp{"3:stderr"}.
  22260. @end deftypevr
  22261. @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
  22262. Allows usage of the auditing subsystem to be altered
  22263. @itemize @bullet
  22264. @item
  22265. 0: disable all auditing
  22266. @item
  22267. 1: enable auditing, only if enabled on host
  22268. @item
  22269. 2: enable auditing, and exit if disabled on host.
  22270. @end itemize
  22271. Defaults to @samp{1}.
  22272. @end deftypevr
  22273. @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
  22274. Send audit messages via libvirt logging infrastructure.
  22275. Defaults to @samp{#f}.
  22276. @end deftypevr
  22277. @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
  22278. Host UUID@. UUID must not have all digits be the same.
  22279. Defaults to @samp{""}.
  22280. @end deftypevr
  22281. @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
  22282. Source to read host UUID.
  22283. @itemize @bullet
  22284. @item
  22285. @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
  22286. @item
  22287. @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
  22288. @end itemize
  22289. If @code{dmidecode} does not provide a valid UUID a temporary UUID will
  22290. be generated.
  22291. Defaults to @samp{"smbios"}.
  22292. @end deftypevr
  22293. @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
  22294. A keepalive message is sent to a client after @code{keepalive_interval}
  22295. seconds of inactivity to check if the client is still responding. If
  22296. set to -1, libvirtd will never send keepalive requests; however clients
  22297. can still send them and the daemon will send responses.
  22298. Defaults to @samp{5}.
  22299. @end deftypevr
  22300. @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
  22301. Maximum number of keepalive messages that are allowed to be sent to the
  22302. client without getting any response before the connection is considered
  22303. broken.
  22304. In other words, the connection is automatically closed approximately
  22305. after @code{keepalive_interval * (keepalive_count + 1)} seconds since
  22306. the last message received from the client. When @code{keepalive-count}
  22307. is set to 0, connections will be automatically closed after
  22308. @code{keepalive-interval} seconds of inactivity without sending any
  22309. keepalive messages.
  22310. Defaults to @samp{5}.
  22311. @end deftypevr
  22312. @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
  22313. Same as above but for admin interface.
  22314. Defaults to @samp{5}.
  22315. @end deftypevr
  22316. @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
  22317. Same as above but for admin interface.
  22318. Defaults to @samp{5}.
  22319. @end deftypevr
  22320. @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
  22321. Timeout for Open vSwitch calls.
  22322. The @code{ovs-vsctl} utility is used for the configuration and its
  22323. timeout option is set by default to 5 seconds to avoid potential
  22324. infinite waits blocking libvirt.
  22325. Defaults to @samp{5}.
  22326. @end deftypevr
  22327. @c %end of autogenerated docs
  22328. @subsubheading Virtlog daemon
  22329. The virtlogd service is a server side daemon component of libvirt that is
  22330. used to manage logs from virtual machine consoles.
  22331. This daemon is not used directly by libvirt client applications, rather it
  22332. is called on their behalf by @code{libvirtd}. By maintaining the logs in a
  22333. standalone daemon, the main @code{libvirtd} daemon can be restarted without
  22334. risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
  22335. itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
  22336. @deffn {Scheme Variable} virtlog-service-type
  22337. This is the type of the virtlog daemon.
  22338. Its value must be a @code{virtlog-configuration}.
  22339. @lisp
  22340. (service virtlog-service-type
  22341. (virtlog-configuration
  22342. (max-clients 1000)))
  22343. @end lisp
  22344. @end deffn
  22345. @deftypevr {@code{virtlog-configuration} parameter} integer log-level
  22346. Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
  22347. Defaults to @samp{3}.
  22348. @end deftypevr
  22349. @deftypevr {@code{virtlog-configuration} parameter} string log-filters
  22350. Logging filters.
  22351. A filter allows to select a different logging level for a given category
  22352. of logs The format for a filter is one of:
  22353. @itemize @bullet
  22354. @item
  22355. x:name
  22356. @item
  22357. x:+name
  22358. @end itemize
  22359. where @code{name} is a string which is matched against the category
  22360. given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
  22361. file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
  22362. be a substring of the full category name, in order to match multiple
  22363. similar categories), the optional "+" prefix tells libvirt to log stack
  22364. trace for each message matching name, and @code{x} is the minimal level
  22365. where matching messages should be logged:
  22366. @itemize @bullet
  22367. @item
  22368. 1: DEBUG
  22369. @item
  22370. 2: INFO
  22371. @item
  22372. 3: WARNING
  22373. @item
  22374. 4: ERROR
  22375. @end itemize
  22376. Multiple filters can be defined in a single filters statement, they just
  22377. need to be separated by spaces.
  22378. Defaults to @samp{"3:remote 4:event"}.
  22379. @end deftypevr
  22380. @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
  22381. Logging outputs.
  22382. An output is one of the places to save logging information The format
  22383. for an output can be:
  22384. @table @code
  22385. @item x:stderr
  22386. output goes to stderr
  22387. @item x:syslog:name
  22388. use syslog for the output and use the given name as the ident
  22389. @item x:file:file_path
  22390. output to a file, with the given filepath
  22391. @item x:journald
  22392. output to journald logging system
  22393. @end table
  22394. In all case the x prefix is the minimal level, acting as a filter
  22395. @itemize @bullet
  22396. @item
  22397. 1: DEBUG
  22398. @item
  22399. 2: INFO
  22400. @item
  22401. 3: WARNING
  22402. @item
  22403. 4: ERROR
  22404. @end itemize
  22405. Multiple outputs can be defined, they just need to be separated by
  22406. spaces.
  22407. Defaults to @samp{"3:stderr"}.
  22408. @end deftypevr
  22409. @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
  22410. Maximum number of concurrent client connections to allow over all
  22411. sockets combined.
  22412. Defaults to @samp{1024}.
  22413. @end deftypevr
  22414. @deftypevr {@code{virtlog-configuration} parameter} integer max-size
  22415. Maximum file size before rolling over.
  22416. Defaults to @samp{2MB}
  22417. @end deftypevr
  22418. @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
  22419. Maximum number of backup files to keep.
  22420. Defaults to @samp{3}
  22421. @end deftypevr
  22422. @anchor{transparent-emulation-qemu}
  22423. @subsubheading Transparent Emulation with QEMU
  22424. @cindex emulation
  22425. @cindex @code{binfmt_misc}
  22426. @code{qemu-binfmt-service-type} provides support for transparent
  22427. emulation of program binaries built for different architectures---e.g.,
  22428. it allows you to transparently execute an ARMv7 program on an x86_64
  22429. machine. It achieves this by combining the @uref{https://www.qemu.org,
  22430. QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
  22431. This feature only allows you to emulate GNU/Linux on a different
  22432. architecture, but see below for GNU/Hurd support.
  22433. @defvr {Scheme Variable} qemu-binfmt-service-type
  22434. This is the type of the QEMU/binfmt service for transparent emulation.
  22435. Its value must be a @code{qemu-binfmt-configuration} object, which
  22436. specifies the QEMU package to use as well as the architecture we want to
  22437. emulated:
  22438. @lisp
  22439. (service qemu-binfmt-service-type
  22440. (qemu-binfmt-configuration
  22441. (platforms (lookup-qemu-platforms "arm" "aarch64"))))
  22442. @end lisp
  22443. In this example, we enable transparent emulation for the ARM and aarch64
  22444. platforms. Running @code{herd stop qemu-binfmt} turns it off, and
  22445. running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
  22446. herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
  22447. @end defvr
  22448. @deftp {Data Type} qemu-binfmt-configuration
  22449. This is the configuration for the @code{qemu-binfmt} service.
  22450. @table @asis
  22451. @item @code{platforms} (default: @code{'()})
  22452. The list of emulated QEMU platforms. Each item must be a @dfn{platform
  22453. object} as returned by @code{lookup-qemu-platforms} (see below).
  22454. For example, let's suppose you're on an x86_64 machine and you have this
  22455. service:
  22456. @lisp
  22457. (service qemu-binfmt-service-type
  22458. (qemu-binfmt-configuration
  22459. (platforms (lookup-qemu-platforms "arm"))))
  22460. @end lisp
  22461. You can run:
  22462. @example
  22463. guix build -s armhf-linux inkscape
  22464. @end example
  22465. @noindent
  22466. and it will build Inkscape for ARMv7 @emph{as if it were a native
  22467. build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
  22468. if you'd like to test a package build for an architecture you don't have
  22469. access to!
  22470. @item @code{qemu} (default: @code{qemu})
  22471. The QEMU package to use.
  22472. @end table
  22473. @end deftp
  22474. @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
  22475. Return the list of QEMU platform objects corresponding to
  22476. @var{platforms}@dots{}. @var{platforms} must be a list of strings
  22477. corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
  22478. @code{"mips64el"}, and so on.
  22479. @end deffn
  22480. @deffn {Scheme Procedure} qemu-platform? @var{obj}
  22481. Return true if @var{obj} is a platform object.
  22482. @end deffn
  22483. @deffn {Scheme Procedure} qemu-platform-name @var{platform}
  22484. Return the name of @var{platform}---a string such as @code{"arm"}.
  22485. @end deffn
  22486. @subsubheading The Hurd in a Virtual Machine
  22487. @cindex @code{hurd}
  22488. @cindex the Hurd
  22489. @cindex childhurd
  22490. Service @code{hurd-vm} provides support for running GNU/Hurd in a
  22491. virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
  22492. to be used on GNU/Linux and the given GNU/Hurd operating system
  22493. configuration is cross-compiled. The virtual machine is a Shepherd
  22494. service that can be referred to by the names @code{hurd-vm} and
  22495. @code{childhurd} and be controlled with commands such as:
  22496. @example
  22497. herd start hurd-vm
  22498. herd stop childhurd
  22499. @end example
  22500. When the service is running, you can view its console by connecting to
  22501. it with a VNC client, for example with:
  22502. @example
  22503. guix environment --ad-hoc tigervnc-client -- \
  22504. vncviewer localhost:5900
  22505. @end example
  22506. The default configuration (see @code{hurd-vm-configuration} below)
  22507. spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
  22508. (the virtual machine emulator) redirects to port 10222 on the host.
  22509. Thus, you can connect over SSH to the childhurd with:
  22510. @example
  22511. ssh root@@localhost -p 10022
  22512. @end example
  22513. The childhurd is volatile and stateless: it starts with a fresh root
  22514. file system every time you restart it. By default though, all the files
  22515. under @file{/etc/childhurd} on the host are copied as is to the root
  22516. file system of the childhurd when it boots. This allows you to
  22517. initialize ``secrets'' inside the VM: SSH host keys, authorized
  22518. substitute keys, and so on---see the explanation of @code{secret-root}
  22519. below.
  22520. @defvr {Scheme Variable} hurd-vm-service-type
  22521. This is the type of the Hurd in a Virtual Machine service. Its value
  22522. must be a @code{hurd-vm-configuration} object, which specifies the
  22523. operating system (@pxref{operating-system Reference}) and the disk size
  22524. for the Hurd Virtual Machine, the QEMU package to use as well as the
  22525. options for running it.
  22526. For example:
  22527. @lisp
  22528. (service hurd-vm-service-type
  22529. (hurd-vm-configuration
  22530. (disk-size (* 5000 (expt 2 20))) ;5G
  22531. (memory-size 1024))) ;1024MiB
  22532. @end lisp
  22533. would create a disk image big enough to build GNU@tie{}Hello, with some
  22534. extra memory.
  22535. @end defvr
  22536. @deftp {Data Type} hurd-vm-configuration
  22537. The data type representing the configuration for
  22538. @code{hurd-vm-service-type}.
  22539. @table @asis
  22540. @item @code{os} (default: @var{%hurd-vm-operating-system})
  22541. The operating system to instantiate. This default is bare-bones with a
  22542. permissive OpenSSH secure shell daemon listening on port 2222
  22543. (@pxref{Networking Services, @code{openssh-service-type}}).
  22544. @item @code{qemu} (default: @code{qemu-minimal})
  22545. The QEMU package to use.
  22546. @item @code{image} (default: @var{hurd-vm-disk-image})
  22547. The procedure used to build the disk-image built from this
  22548. configuration.
  22549. @item @code{disk-size} (default: @code{'guess})
  22550. The size of the disk image.
  22551. @item @code{memory-size} (default: @code{512})
  22552. The memory size of the Virtual Machine in mebibytes.
  22553. @item @code{options} (default: @code{'("--snapshot")})
  22554. The extra options for running QEMU.
  22555. @item @code{id} (default: @code{#f})
  22556. If set, a non-zero positive integer used to parameterize Childhurd
  22557. instances. It is appended to the service's name,
  22558. e.g. @code{childhurd1}.
  22559. @item @code{net-options} (default: @var{hurd-vm-net-options})
  22560. The procedure used to produce the list of QEMU networking options.
  22561. By default, it produces
  22562. @lisp
  22563. '("--device" "rtl8139,netdev=net0"
  22564. "--netdev" "user,id=net0\
  22565. ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
  22566. ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
  22567. ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
  22568. @end lisp
  22569. with forwarded ports:
  22570. @example
  22571. @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
  22572. @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
  22573. @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
  22574. @end example
  22575. @item @code{secret-root} (default: @file{/etc/childhurd})
  22576. The root directory with out-of-band secrets to be installed into the
  22577. childhurd once it runs. Childhurds are volatile which means that on
  22578. every startup, secrets such as the SSH host keys and Guix signing key
  22579. are recreated.
  22580. If the @file{/etc/childhurd} directory does not exist, the
  22581. @code{secret-service} running in the Childhurd will be sent an empty
  22582. list of secrets.
  22583. By default, the service automatically populates @file{/etc/childhurd}
  22584. with the following non-volatile secrets, unless they already exist:
  22585. @example
  22586. /etc/childhurd/etc/guix/acl
  22587. /etc/childhurd/etc/guix/signing-key.pub
  22588. /etc/childhurd/etc/guix/signing-key.sec
  22589. /etc/childhurd/etc/ssh/ssh_host_ed25519_key
  22590. /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
  22591. /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
  22592. /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
  22593. @end example
  22594. These files are automatically sent to the guest Hurd VM when it boots,
  22595. including permissions.
  22596. @cindex childhurd, offloading
  22597. @cindex Hurd, offloading
  22598. Having these files in place means that only a couple of things are
  22599. missing to allow the host to offload @code{i586-gnu} builds to the
  22600. childhurd:
  22601. @enumerate
  22602. @item
  22603. Authorizing the childhurd's key on the host so that the host accepts
  22604. build results coming from the childhurd, which can be done like so:
  22605. @example
  22606. guix archive --authorize < \
  22607. /etc/childhurd/etc/guix/signing-key.pub
  22608. @end example
  22609. @item
  22610. Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
  22611. Offload Setup}).
  22612. @end enumerate
  22613. We're working towards making that happen automatically---get in touch
  22614. with us at @email{guix-devel@@gnu.org} to discuss it!
  22615. @end table
  22616. @end deftp
  22617. Note that by default the VM image is volatile, i.e., once stopped the
  22618. contents are lost. If you want a stateful image instead, override the
  22619. configuration's @code{image} and @code{options} without
  22620. the @code{--snapshot} flag using something along these lines:
  22621. @lisp
  22622. (service hurd-vm-service-type
  22623. (hurd-vm-configuration
  22624. (image (const "/out/of/store/writable/hurd.img"))
  22625. (options '())))
  22626. @end lisp
  22627. @subsubheading Ganeti
  22628. @cindex ganeti
  22629. @quotation Note
  22630. This service is considered experimental. Configuration options may be changed
  22631. in a backwards-incompatible manner, and not all features have been thorougly
  22632. tested. Users of this service are encouraged to share their experience at
  22633. @email{guix-devel@@gnu.org}.
  22634. @end quotation
  22635. Ganeti is a virtual machine management system. It is designed to keep virtual
  22636. machines running on a cluster of servers even in the event of hardware failures,
  22637. and to make maintenance and recovery tasks easy. It consists of multiple
  22638. services which are described later in this section. In addition to the Ganeti
  22639. service, you will need the OpenSSH service (@pxref{Networking Services,
  22640. @code{openssh-service-type}}), and update the @file{/etc/hosts} file
  22641. (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
  22642. and address (or use a DNS server).
  22643. All nodes participating in a Ganeti cluster should have the same Ganeti and
  22644. @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
  22645. cluster node that supports multiple storage backends, and installs the
  22646. @code{debootstrap} and @code{guix} @dfn{OS providers}:
  22647. @lisp
  22648. (use-package-modules virtualization)
  22649. (use-service-modules base ganeti networking ssh)
  22650. (operating-system
  22651. ;; @dots{}
  22652. (host-name "node1")
  22653. (hosts-file (plain-file "hosts" (format #f "
  22654. 127.0.0.1 localhost
  22655. ::1 localhost
  22656. 192.168.1.200 ganeti.example.com
  22657. 192.168.1.201 node1.example.com node1
  22658. 192.168.1.202 node2.example.com node2
  22659. ")))
  22660. ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
  22661. ;; in order to use the "plain", "drbd" and "rbd" storage backends.
  22662. (packages (append (map specification->package
  22663. '("qemu" "lvm2" "drbd-utils" "ceph"
  22664. ;; Add the debootstrap and guix OS providers.
  22665. "ganeti-instance-guix" "ganeti-instance-debootstrap"))
  22666. %base-packages))
  22667. (services
  22668. (append (list (static-networking-service "eth0" "192.168.1.201"
  22669. #:netmask "255.255.255.0"
  22670. #:gateway "192.168.1.254"
  22671. #:name-servers '("192.168.1.252"
  22672. "192.168.1.253"))
  22673. ;; Ganeti uses SSH to communicate between nodes.
  22674. (service openssh-service-type
  22675. (openssh-configuration
  22676. (permit-root-login 'without-password)))
  22677. (service ganeti-service-type
  22678. (ganeti-configuration
  22679. ;; This list specifies allowed file system paths
  22680. ;; for storing virtual machine images.
  22681. (file-storage-paths '("/srv/ganeti/file-storage"))
  22682. ;; This variable configures a single "variant" for
  22683. ;; both Debootstrap and Guix that works with KVM.
  22684. (os %default-ganeti-os))))
  22685. %base-services)))
  22686. @end lisp
  22687. Users are advised to read the
  22688. @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
  22689. administrators guide} to learn about the various cluster options and
  22690. day-to-day operations. There is also a
  22691. @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
  22692. describing how to configure and initialize a small cluster.
  22693. @defvr {Scheme Variable} ganeti-service-type
  22694. This is a service type that includes all the various services that Ganeti
  22695. nodes should run.
  22696. Its value is a @code{ganeti-configuration} object that defines the package
  22697. to use for CLI operations, as well as configuration for the various daemons.
  22698. Allowed file storage paths and available guest operating systems are also
  22699. configured through this data type.
  22700. @end defvr
  22701. @deftp {Data Type} ganeti-configuration
  22702. The @code{ganeti} service takes the following configuration options:
  22703. @table @asis
  22704. @item @code{ganeti} (default: @code{ganeti})
  22705. The @code{ganeti} package to use. It will be installed to the system profile
  22706. and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
  22707. that the value specified here does not affect the other services as each refer
  22708. to a specific @code{ganeti} package (see below).
  22709. @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
  22710. @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
  22711. @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
  22712. @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
  22713. @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
  22714. @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
  22715. @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
  22716. @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
  22717. @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
  22718. @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
  22719. These options control the various daemons and cron jobs that are distributed
  22720. with Ganeti. The possible values for these are described in detail below.
  22721. To override a setting, you must use the configuration type for that service:
  22722. @lisp
  22723. (service ganeti-service-type
  22724. (ganeti-configuration
  22725. (rapi-configuration
  22726. (ganeti-rapi-configuration
  22727. (interface "eth1"))))
  22728. (watcher-configuration
  22729. (ganeti-watcher-configuration
  22730. (rapi-ip "10.0.0.1"))))
  22731. @end lisp
  22732. @item @code{file-storage-paths} (default: @code{'()})
  22733. List of allowed directories for file storage backend.
  22734. @item @code{os} (default: @code{%default-ganeti-os})
  22735. List of @code{<ganeti-os>} records.
  22736. @end table
  22737. In essence @code{ganeti-service-type} is shorthand for declaring each service
  22738. individually:
  22739. @lisp
  22740. (service ganeti-noded-service-type)
  22741. (service ganeti-confd-service-type)
  22742. (service ganeti-wconfd-service-type)
  22743. (service ganeti-luxid-service-type)
  22744. (service ganeti-kvmd-service-type)
  22745. (service ganeti-mond-service-type)
  22746. (service ganeti-metad-service-type)
  22747. (service ganeti-watcher-service-type)
  22748. (service ganeti-cleaner-service-type)
  22749. @end lisp
  22750. Plus a service extension for @code{etc-service-type} that configures the file
  22751. storage backend and OS variants.
  22752. @end deftp
  22753. @deftp {Data Type} ganeti-os
  22754. This data type is suitable for passing to the @code{os} parameter of
  22755. @code{ganeti-configuration}. It takes the following parameters:
  22756. @table @asis
  22757. @item @code{name}
  22758. The name for this OS provider. It is only used to specify where the
  22759. configuration ends up. Setting it to ``debootstrap'' will create
  22760. @file{/etc/ganeti/instance-debootstrap}.
  22761. @item @code{extension}
  22762. The file extension for variants of this OS type. For example
  22763. @file{.conf} or @file{.scm}.
  22764. @item @code{variants} (default: @code{'()})
  22765. List of @code{ganeti-os-variant} objects for this OS.
  22766. @end table
  22767. @end deftp
  22768. @deftp {Data Type} ganeti-os-variant
  22769. This is the data type for a Ganeti OS variant. It takes the following
  22770. parameters:
  22771. @table @asis
  22772. @item @code{name}
  22773. The name of this variant.
  22774. @item @code{configuration}
  22775. A configuration file for this variant.
  22776. @end table
  22777. @end deftp
  22778. @defvr {Scheme Variable} %default-debootstrap-hooks
  22779. This variable contains hooks to configure networking and the GRUB bootloader.
  22780. @end defvr
  22781. @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
  22782. This variable contains a list of packages suitable for a fully-virtualized guest.
  22783. @end defvr
  22784. @deftp {Data Type} debootstrap-configuration
  22785. This data type creates configuration files suitable for the debootstrap OS provider.
  22786. @table @asis
  22787. @item @code{hooks} (default: @code{%default-debootstrap-hooks})
  22788. When not @code{#f}, this must be a G-expression that specifies a directory with
  22789. scripts that will run when the OS is installed. It can also be a list of
  22790. @code{(name . file-like)} pairs. For example:
  22791. @lisp
  22792. `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
  22793. @end lisp
  22794. That will create a directory with one executable named @code{99-hello-world}
  22795. and run it every time this variant is installed. If set to @code{#f}, hooks
  22796. in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
  22797. @item @code{proxy} (default: @code{#f})
  22798. Optional HTTP proxy to use.
  22799. @item @code{mirror} (default: @code{#f})
  22800. The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
  22801. The default varies depending on the distribution.
  22802. @item @code{arch} (default: @code{#f})
  22803. The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
  22804. on an AArch64 host. Default is to use the current system architecture.
  22805. @item @code{suite} (default: @code{"stable"})
  22806. When set, this must be a Debian distribution ``suite'' such as @code{buster}
  22807. or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
  22808. @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
  22809. List of extra packages that will get installed by dpkg in addition
  22810. to the minimal system.
  22811. @item @code{components} (default: @code{#f})
  22812. When set, must be a list of Debian repository ``components''. For example
  22813. @code{'("main" "contrib")}.
  22814. @item @code{generate-cache?} (default: @code{#t})
  22815. Whether to automatically cache the generated debootstrap archive.
  22816. @item @code{clean-cache} (default: @code{14})
  22817. Discard the cache after this amount of days. Use @code{#f} to never
  22818. clear the cache.
  22819. @item @code{partition-style} (default: @code{'msdos})
  22820. The type of partition to create. When set, it must be one of
  22821. @code{'msdos}, @code{'none} or a string.
  22822. @item @code{partition-alignment} (default: @code{2048})
  22823. Alignment of the partition in sectors.
  22824. @end table
  22825. @end deftp
  22826. @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
  22827. This is a helper procedure that creates a @code{ganeti-os-variant} record. It
  22828. takes two parameters: a name and a @code{debootstrap-configuration} object.
  22829. @end deffn
  22830. @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
  22831. This is a helper procedure that creates a @code{ganeti-os} record. It takes
  22832. a list of variants created with @code{debootstrap-variant}.
  22833. @end deffn
  22834. @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
  22835. This is a helper procedure that creates a @code{ganeti-os-variant} record for
  22836. use with the Guix OS provider. It takes a name and a G-expression that returns
  22837. a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
  22838. Guix System configuration.
  22839. @end deffn
  22840. @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
  22841. This is a helper procedure that creates a @code{ganeti-os} record. It
  22842. takes a list of variants produced by @code{guix-variant}.
  22843. @end deffn
  22844. @defvr {Scheme Variable} %default-debootstrap-variants
  22845. This is a convenience variable to make the debootstrap provider work
  22846. ``out of the box'' without users having to declare variants manually. It
  22847. contains a single debootstrap variant with the default configuration:
  22848. @lisp
  22849. (list (debootstrap-variant
  22850. "default"
  22851. (debootstrap-configuration)))
  22852. @end lisp
  22853. @end defvr
  22854. @defvr {Scheme Variable} %default-guix-variants
  22855. This is a convenience variable to make the Guix OS provider work without
  22856. additional configuration. It creates a virtual machine that has an SSH
  22857. server, a serial console, and authorizes the Ganeti hosts SSH keys.
  22858. @lisp
  22859. (list (guix-variant
  22860. "default"
  22861. (file-append ganeti-instance-guix
  22862. "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
  22863. @end lisp
  22864. @end defvr
  22865. Users can implement support for OS providers unbeknownst to Guix by extending
  22866. the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
  22867. For example:
  22868. @lisp
  22869. (ganeti-os
  22870. (name "custom")
  22871. (extension ".conf")
  22872. (variants
  22873. (list (ganeti-os-variant
  22874. (name "foo")
  22875. (configuration (plain-file "bar" "this is fine"))))))
  22876. @end lisp
  22877. That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
  22878. to a file in the store with contents @code{this is fine}. It also creates
  22879. @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
  22880. Obviously this may not work for all OS providers out there. If you find the
  22881. interface limiting, please reach out to @email{guix-devel@@gnu.org}.
  22882. The rest of this section documents the various services that are included by
  22883. @code{ganeti-service-type}.
  22884. @defvr {Scheme Variable} ganeti-noded-service-type
  22885. @command{ganeti-noded} is the daemon responsible for node-specific functions
  22886. within the Ganeti system. The value of this service must be a
  22887. @code{ganeti-noded-configuration} object.
  22888. @end defvr
  22889. @deftp {Data Type} ganeti-noded-configuration
  22890. This is the configuration for the @code{ganeti-noded} service.
  22891. @table @asis
  22892. @item @code{ganeti} (default: @code{ganeti})
  22893. The @code{ganeti} package to use for this service.
  22894. @item @code{port} (default: @code{1811})
  22895. The TCP port on which the node daemon listens for network requests.
  22896. @item @code{address} (default: @code{"0.0.0.0"})
  22897. The network address that the daemon will bind to. The default address means
  22898. bind to all available addresses.
  22899. @item @code{interface} (default: @code{#f})
  22900. When this is set, it must be a specific network interface (e.g.@: @code{eth0})
  22901. that the daemon will bind to.
  22902. @item @code{max-clients} (default: @code{20})
  22903. This sets a limit on the maximum number of simultaneous client connections
  22904. that the daemon will handle. Connections above this count are accepted, but
  22905. no responses will be sent until enough connections have closed.
  22906. @item @code{ssl?} (default: @code{#t})
  22907. Whether to use SSL/TLS to encrypt network communications. The certificate
  22908. is automatically provisioned by the cluster and can be rotated with
  22909. @command{gnt-cluster renew-crypto}.
  22910. @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
  22911. This can be used to provide a specific encryption key for TLS communications.
  22912. @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
  22913. This can be used to provide a specific certificate for TLS communications.
  22914. @item @code{debug?} (default: @code{#f})
  22915. When true, the daemon performs additional logging for debugging purposes.
  22916. Note that this will leak encryption details to the log files, use with caution.
  22917. @end table
  22918. @end deftp
  22919. @defvr {Scheme Variable} ganeti-confd-service-type
  22920. @command{ganeti-confd} answers queries related to the configuration of a
  22921. Ganeti cluster. The purpose of this daemon is to have a highly available
  22922. and fast way to query cluster configuration values. It is automatically
  22923. active on all @dfn{master candidates}. The value of this service must be a
  22924. @code{ganeti-confd-configuration} object.
  22925. @end defvr
  22926. @deftp {Data Type} ganeti-confd-configuration
  22927. This is the configuration for the @code{ganeti-confd} service.
  22928. @table @asis
  22929. @item @code{ganeti} (default: @code{ganeti})
  22930. The @code{ganeti} package to use for this service.
  22931. @item @code{port} (default: @code{1814})
  22932. The UDP port on which to listen for network requests.
  22933. @item @code{address} (default: @code{"0.0.0.0"})
  22934. Network address that the daemon will bind to.
  22935. @item @code{debug?} (default: @code{#f})
  22936. When true, the daemon performs additional logging for debugging purposes.
  22937. @end table
  22938. @end deftp
  22939. @defvr {Scheme Variable} ganeti-wconfd-service-type
  22940. @command{ganeti-wconfd} is the daemon that has authoritative knowledge
  22941. about the cluster configuration and is the only entity that can accept
  22942. changes to it. All jobs that need to modify the configuration will do so
  22943. by sending appropriate requests to this daemon. It only runs on the
  22944. @dfn{master node} and will automatically disable itself on other nodes.
  22945. The value of this service must be a
  22946. @code{ganeti-wconfd-configuration} object.
  22947. @end defvr
  22948. @deftp {Data Type} ganeti-wconfd-configuration
  22949. This is the configuration for the @code{ganeti-wconfd} service.
  22950. @table @asis
  22951. @item @code{ganeti} (default: @code{ganeti})
  22952. The @code{ganeti} package to use for this service.
  22953. @item @code{no-voting?} (default: @code{#f})
  22954. The daemon will refuse to start if the majority of cluster nodes does not
  22955. agree that it is running on the master node. Set to @code{#t} to start
  22956. even if a quorum can not be reached (dangerous, use with caution).
  22957. @item @code{debug?} (default: @code{#f})
  22958. When true, the daemon performs additional logging for debugging purposes.
  22959. @end table
  22960. @end deftp
  22961. @defvr {Scheme Variable} ganeti-luxid-service-type
  22962. @command{ganeti-luxid} is a daemon used to answer queries related to the
  22963. configuration and the current live state of a Ganeti cluster. Additionally,
  22964. it is the authoritative daemon for the Ganeti job queue. Jobs can be
  22965. submitted via this daemon and it schedules and starts them.
  22966. It takes a @code{ganeti-luxid-configuration} object.
  22967. @end defvr
  22968. @deftp {Data Type} ganeti-luxid-configuration
  22969. This is the configuration for the @code{ganeti-wconfd} service.
  22970. @table @asis
  22971. @item @code{ganeti} (default: @code{ganeti})
  22972. The @code{ganeti} package to use for this service.
  22973. @item @code{no-voting?} (default: @code{#f})
  22974. The daemon will refuse to start if it cannot verify that the majority of
  22975. cluster nodes believes that it is running on the master node. Set to
  22976. @code{#t} to ignore such checks and start anyway (this can be dangerous).
  22977. @item @code{debug?} (default: @code{#f})
  22978. When true, the daemon performs additional logging for debugging purposes.
  22979. @end table
  22980. @end deftp
  22981. @defvr {Scheme Variable} ganeti-rapi-service-type
  22982. @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
  22983. the master node and can be used to perform cluster actions programmatically
  22984. via a JSON-based RPC protocol.
  22985. Most query operations are allowed without authentication (unless
  22986. @var{require-authentication?} is set), whereas write operations require
  22987. explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
  22988. the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
  22989. API documentation} for more information.
  22990. The value of this service must be a @code{ganeti-rapi-configuration} object.
  22991. @end defvr
  22992. @deftp {Data Type} ganeti-rapi-configuration
  22993. This is the configuration for the @code{ganeti-rapi} service.
  22994. @table @asis
  22995. @item @code{ganeti} (default: @code{ganeti})
  22996. The @code{ganeti} package to use for this service.
  22997. @item @code{require-authentication?} (default: @code{#f})
  22998. Whether to require authentication even for read-only operations.
  22999. @item @code{port} (default: @code{5080})
  23000. The TCP port on which to listen to API requests.
  23001. @item @code{address} (default: @code{"0.0.0.0"})
  23002. The network address that the service will bind to. By default it listens
  23003. on all configured addresses.
  23004. @item @code{interface} (default: @code{#f})
  23005. When set, it must specify a specific network interface such as @code{eth0}
  23006. that the daemon will bind to.
  23007. @item @code{max-clients} (default: @code{20})
  23008. The maximum number of simultaneous client requests to handle. Further
  23009. connections are allowed, but no responses are sent until enough connections
  23010. have closed.
  23011. @item @code{ssl?} (default: @code{#t})
  23012. Whether to use SSL/TLS encryption on the RAPI port.
  23013. @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
  23014. This can be used to provide a specific encryption key for TLS communications.
  23015. @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
  23016. This can be used to provide a specific certificate for TLS communications.
  23017. @item @code{debug?} (default: @code{#f})
  23018. When true, the daemon performs additional logging for debugging purposes.
  23019. Note that this will leak encryption details to the log files, use with caution.
  23020. @end table
  23021. @end deftp
  23022. @defvr {Scheme Variable} ganeti-kvmd-service-type
  23023. @command{ganeti-kvmd} is responsible for determining whether a given KVM
  23024. instance was shut down by an administrator or a user. Normally Ganeti will
  23025. restart an instance that was not stopped through Ganeti itself. If the
  23026. cluster option @code{user_shutdown} is true, this daemon monitors the
  23027. @code{QMP} socket provided by QEMU and listens for shutdown events, and
  23028. marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
  23029. it shuts down gracefully by itself.
  23030. It takes a @code{ganeti-kvmd-configuration} object.
  23031. @end defvr
  23032. @deftp {Data Type} ganeti-kvmd-configuration
  23033. @table @asis
  23034. @item @code{ganeti} (default: @code{ganeti})
  23035. The @code{ganeti} package to use for this service.
  23036. @item @code{debug?} (default: @code{#f})
  23037. When true, the daemon performs additional logging for debugging purposes.
  23038. @end table
  23039. @end deftp
  23040. @defvr {Scheme Variable} ganeti-mond-service-type
  23041. @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
  23042. functionality. It is responsible for running data collectors and publish the
  23043. collected information through a HTTP interface.
  23044. It takes a @code{ganeti-mond-configuration} object.
  23045. @end defvr
  23046. @deftp {Data Type} ganeti-mond-configuration
  23047. @table @asis
  23048. @item @code{ganeti} (default: @code{ganeti})
  23049. The @code{ganeti} package to use for this service.
  23050. @item @code{port} (default: @code{1815})
  23051. The port on which the daemon will listen.
  23052. @item @code{address} (default: @code{"0.0.0.0"})
  23053. The network address that the daemon will bind to. By default it binds to all
  23054. available interfaces.
  23055. @item @code{debug?} (default: @code{#f})
  23056. When true, the daemon performs additional logging for debugging purposes.
  23057. @end table
  23058. @end deftp
  23059. @defvr {Scheme Variable} ganeti-metad-service-type
  23060. @command{ganeti-metad} is an optional daemon that can be used to provide
  23061. information about the cluster to instances or OS install scripts.
  23062. It takes a @code{ganeti-metad-configuration} object.
  23063. @end defvr
  23064. @deftp {Data Type} ganeti-metad-configuration
  23065. @table @asis
  23066. @item @code{ganeti} (default: @code{ganeti})
  23067. The @code{ganeti} package to use for this service.
  23068. @item @code{port} (default: @code{80})
  23069. The port on which the daemon will listen.
  23070. @item @code{address} (default: @code{#f})
  23071. If set, the daemon will bind to this address only. If left unset, the behavior
  23072. depends on the cluster configuration.
  23073. @item @code{debug?} (default: @code{#f})
  23074. When true, the daemon performs additional logging for debugging purposes.
  23075. @end table
  23076. @end deftp
  23077. @defvr {Scheme Variable} ganeti-watcher-service-type
  23078. @command{ganeti-watcher} is a script designed to run periodically and ensure
  23079. the health of a cluster. It will automatically restart instances that have
  23080. stopped without Ganeti's consent, and repairs DRBD links in case a node has
  23081. rebooted. It also archives old cluster jobs and restarts Ganeti daemons
  23082. that are not running. If the cluster parameter @code{ensure_node_health}
  23083. is set, the watcher will also shutdown instances and DRBD devices if the
  23084. node it is running on is declared offline by known master candidates.
  23085. It can be paused on all nodes with @command{gnt-cluster watcher pause}.
  23086. The service takes a @code{ganeti-watcher-configuration} object.
  23087. @end defvr
  23088. @deftp {Data Type} ganeti-watcher-configuration
  23089. @table @asis
  23090. @item @code{ganeti} (default: @code{ganeti})
  23091. The @code{ganeti} package to use for this service.
  23092. @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
  23093. How often to run the script. The default is every five minutes.
  23094. @item @code{rapi-ip} (default: @code{#f})
  23095. This option needs to be specified only if the RAPI daemon is configured to use
  23096. a particular interface or address. By default the cluster address is used.
  23097. @item @code{job-age} (default: @code{(* 6 3600)})
  23098. Archive cluster jobs older than this age, specified in seconds. The default
  23099. is 6 hours. This keeps @command{gnt-job list} manageable.
  23100. @item @code{verify-disks?} (default: @code{#t})
  23101. If this is @code{#f}, the watcher will not try to repair broken DRBD links
  23102. automatically. Administrators will need to use @command{gnt-cluster verify-disks}
  23103. manually instead.
  23104. @item @code{debug?} (default: @code{#f})
  23105. When @code{#t}, the script performs additional logging for debugging purposes.
  23106. @end table
  23107. @end deftp
  23108. @defvr {Scheme Variable} ganeti-cleaner-service-type
  23109. @command{ganeti-cleaner} is a script designed to run periodically and remove
  23110. old files from the cluster. This service type controls two @dfn{cron jobs}:
  23111. one intended for the master node that permanently purges old cluster jobs,
  23112. and one intended for every node that removes expired X509 certificates, keys,
  23113. and outdated @command{ganeti-watcher} information. Like all Ganeti services,
  23114. it is safe to include even on non-master nodes as it will disable itself as
  23115. necessary.
  23116. It takes a @code{ganeti-cleaner-configuration} object.
  23117. @end defvr
  23118. @deftp {Data Type} ganeti-cleaner-configuration
  23119. @table @asis
  23120. @item @code{ganeti} (default: @code{ganeti})
  23121. The @code{ganeti} package to use for the @command{gnt-cleaner} command.
  23122. @item @code{master-schedule} (default: @code{"45 1 * * *"})
  23123. How often to run the master cleaning job. The default is once per day, at
  23124. 01:45:00.
  23125. @item @code{node-schedule} (default: @code{"45 2 * * *"})
  23126. How often to run the node cleaning job. The default is once per day, at
  23127. 02:45:00.
  23128. @end table
  23129. @end deftp
  23130. @node Version Control Services
  23131. @subsection Version Control Services
  23132. The @code{(gnu services version-control)} module provides a service to
  23133. allow remote access to local Git repositories. There are three options:
  23134. the @code{git-daemon-service}, which provides access to repositories via
  23135. the @code{git://} unsecured TCP-based protocol, extending the
  23136. @code{nginx} web server to proxy some requests to
  23137. @code{git-http-backend}, or providing a web interface with
  23138. @code{cgit-service-type}.
  23139. @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
  23140. Return a service that runs @command{git daemon}, a simple TCP server to
  23141. expose repositories over the Git protocol for anonymous access.
  23142. The optional @var{config} argument should be a
  23143. @code{<git-daemon-configuration>} object, by default it allows read-only
  23144. access to exported@footnote{By creating the magic file
  23145. @file{git-daemon-export-ok} in the repository directory.} repositories under
  23146. @file{/srv/git}.
  23147. @end deffn
  23148. @deftp {Data Type} git-daemon-configuration
  23149. Data type representing the configuration for @code{git-daemon-service}.
  23150. @table @asis
  23151. @item @code{package} (default: @code{git})
  23152. Package object of the Git distributed version control system.
  23153. @item @code{export-all?} (default: @code{#f})
  23154. Whether to allow access for all Git repositories, even if they do not
  23155. have the @file{git-daemon-export-ok} file.
  23156. @item @code{base-path} (default: @file{/srv/git})
  23157. Whether to remap all the path requests as relative to the given path.
  23158. If you run @command{git daemon} with @code{(base-path "/srv/git")} on
  23159. @samp{example.com}, then if you later try to pull
  23160. @indicateurl{git://example.com/hello.git}, git daemon will interpret the
  23161. path as @file{/srv/git/hello.git}.
  23162. @item @code{user-path} (default: @code{#f})
  23163. Whether to allow @code{~user} notation to be used in requests. When
  23164. specified with empty string, requests to
  23165. @indicateurl{git://host/~alice/foo} is taken as a request to access
  23166. @code{foo} repository in the home directory of user @code{alice}. If
  23167. @code{(user-path "@var{path}")} is specified, the same request is taken
  23168. as a request to access @file{@var{path}/foo} repository in the home
  23169. directory of user @code{alice}.
  23170. @item @code{listen} (default: @code{'()})
  23171. Whether to listen on specific IP addresses or hostnames, defaults to
  23172. all.
  23173. @item @code{port} (default: @code{#f})
  23174. Whether to listen on an alternative port, which defaults to 9418.
  23175. @item @code{whitelist} (default: @code{'()})
  23176. If not empty, only allow access to this list of directories.
  23177. @item @code{extra-options} (default: @code{'()})
  23178. Extra options will be passed to @command{git daemon}, please run
  23179. @command{man git-daemon} for more information.
  23180. @end table
  23181. @end deftp
  23182. The @code{git://} protocol lacks authentication. When you pull from a
  23183. repository fetched via @code{git://}, you don't know whether the data you
  23184. receive was modified or is even coming from the specified host, and your
  23185. connection is subject to eavesdropping. It's better to use an authenticated
  23186. and encrypted transport, such as @code{https}. Although Git allows you
  23187. to serve repositories using unsophisticated file-based web servers,
  23188. there is a faster protocol implemented by the @code{git-http-backend}
  23189. program. This program is the back-end of a proper Git web service. It
  23190. is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
  23191. on running the necessary @code{fcgiwrap} daemon.
  23192. Guix has a separate configuration data type for serving Git repositories
  23193. over HTTP.
  23194. @deftp {Data Type} git-http-configuration
  23195. Data type representing the configuration for a future
  23196. @code{git-http-service-type}; can currently be used to configure Nginx
  23197. through @code{git-http-nginx-location-configuration}.
  23198. @table @asis
  23199. @item @code{package} (default: @var{git})
  23200. Package object of the Git distributed version control system.
  23201. @item @code{git-root} (default: @file{/srv/git})
  23202. Directory containing the Git repositories to expose to the world.
  23203. @item @code{export-all?} (default: @code{#f})
  23204. Whether to expose access for all Git repositories in @var{git-root},
  23205. even if they do not have the @file{git-daemon-export-ok} file.
  23206. @item @code{uri-path} (default: @samp{/git/})
  23207. Path prefix for Git access. With the default @samp{/git/} prefix, this
  23208. will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
  23209. @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
  23210. with this prefix are not passed on to this Git instance.
  23211. @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
  23212. The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
  23213. Services}.
  23214. @end table
  23215. @end deftp
  23216. There is no @code{git-http-service-type}, currently; instead you can
  23217. create an @code{nginx-location-configuration} from a
  23218. @code{git-http-configuration} and then add that location to a web
  23219. server.
  23220. @deffn {Scheme Procedure} git-http-nginx-location-configuration @
  23221. [config=(git-http-configuration)]
  23222. Compute an @code{nginx-location-configuration} that corresponds to the
  23223. given Git http configuration. An example nginx service definition to
  23224. serve the default @file{/srv/git} over HTTPS might be:
  23225. @lisp
  23226. (service nginx-service-type
  23227. (nginx-configuration
  23228. (server-blocks
  23229. (list
  23230. (nginx-server-configuration
  23231. (listen '("443 ssl"))
  23232. (server-name "git.my-host.org")
  23233. (ssl-certificate
  23234. "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
  23235. (ssl-certificate-key
  23236. "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
  23237. (locations
  23238. (list
  23239. (git-http-nginx-location-configuration
  23240. (git-http-configuration (uri-path "/"))))))))))
  23241. @end lisp
  23242. This example assumes that you are using Let's Encrypt to get your TLS
  23243. certificate. @xref{Certificate Services}. The default @code{certbot}
  23244. service will redirect all HTTP traffic on @code{git.my-host.org} to
  23245. HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
  23246. system services. @xref{Web Services}.
  23247. @end deffn
  23248. @subsubheading Cgit Service
  23249. @cindex Cgit service
  23250. @cindex Git, web interface
  23251. @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
  23252. repositories written in C.
  23253. The following example will configure the service with default values.
  23254. By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
  23255. @lisp
  23256. (service cgit-service-type)
  23257. @end lisp
  23258. The @code{file-object} type designates either a file-like object
  23259. (@pxref{G-Expressions, file-like objects}) or a string.
  23260. @c %start of fragment
  23261. Available @code{cgit-configuration} fields are:
  23262. @deftypevr {@code{cgit-configuration} parameter} package package
  23263. The CGIT package.
  23264. @end deftypevr
  23265. @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
  23266. NGINX configuration.
  23267. @end deftypevr
  23268. @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
  23269. Specifies a command which will be invoked to format the content of about
  23270. pages (both top-level and for each repository).
  23271. Defaults to @samp{""}.
  23272. @end deftypevr
  23273. @deftypevr {@code{cgit-configuration} parameter} string agefile
  23274. Specifies a path, relative to each repository path, which can be used to
  23275. specify the date and time of the youngest commit in the repository.
  23276. Defaults to @samp{""}.
  23277. @end deftypevr
  23278. @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
  23279. Specifies a command that will be invoked for authenticating repository
  23280. access.
  23281. Defaults to @samp{""}.
  23282. @end deftypevr
  23283. @deftypevr {@code{cgit-configuration} parameter} string branch-sort
  23284. Flag which, when set to @samp{age}, enables date ordering in the branch
  23285. ref list, and when set @samp{name} enables ordering by branch name.
  23286. Defaults to @samp{"name"}.
  23287. @end deftypevr
  23288. @deftypevr {@code{cgit-configuration} parameter} string cache-root
  23289. Path used to store the cgit cache entries.
  23290. Defaults to @samp{"/var/cache/cgit"}.
  23291. @end deftypevr
  23292. @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
  23293. Number which specifies the time-to-live, in minutes, for the cached
  23294. version of repository pages accessed with a fixed SHA1.
  23295. Defaults to @samp{-1}.
  23296. @end deftypevr
  23297. @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
  23298. Number which specifies the time-to-live, in minutes, for the cached
  23299. version of repository pages accessed without a fixed SHA1.
  23300. Defaults to @samp{5}.
  23301. @end deftypevr
  23302. @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
  23303. Number which specifies the time-to-live, in minutes, for the cached
  23304. version of the repository summary page.
  23305. Defaults to @samp{5}.
  23306. @end deftypevr
  23307. @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
  23308. Number which specifies the time-to-live, in minutes, for the cached
  23309. version of the repository index page.
  23310. Defaults to @samp{5}.
  23311. @end deftypevr
  23312. @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
  23313. Number which specifies the time-to-live, in minutes, for the result of
  23314. scanning a path for Git repositories.
  23315. Defaults to @samp{15}.
  23316. @end deftypevr
  23317. @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
  23318. Number which specifies the time-to-live, in minutes, for the cached
  23319. version of the repository about page.
  23320. Defaults to @samp{15}.
  23321. @end deftypevr
  23322. @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
  23323. Number which specifies the time-to-live, in minutes, for the cached
  23324. version of snapshots.
  23325. Defaults to @samp{5}.
  23326. @end deftypevr
  23327. @deftypevr {@code{cgit-configuration} parameter} integer cache-size
  23328. The maximum number of entries in the cgit cache. When set to @samp{0},
  23329. caching is disabled.
  23330. Defaults to @samp{0}.
  23331. @end deftypevr
  23332. @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
  23333. Sort items in the repo list case sensitively.
  23334. Defaults to @samp{#t}.
  23335. @end deftypevr
  23336. @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
  23337. List of common prefixes which, when combined with a repository URL,
  23338. generates valid clone URLs for the repository.
  23339. Defaults to @samp{()}.
  23340. @end deftypevr
  23341. @deftypevr {@code{cgit-configuration} parameter} list clone-url
  23342. List of @code{clone-url} templates.
  23343. Defaults to @samp{()}.
  23344. @end deftypevr
  23345. @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
  23346. Command which will be invoked to format commit messages.
  23347. Defaults to @samp{""}.
  23348. @end deftypevr
  23349. @deftypevr {@code{cgit-configuration} parameter} string commit-sort
  23350. Flag which, when set to @samp{date}, enables strict date ordering in the
  23351. commit log, and when set to @samp{topo} enables strict topological
  23352. ordering.
  23353. Defaults to @samp{"git log"}.
  23354. @end deftypevr
  23355. @deftypevr {@code{cgit-configuration} parameter} file-object css
  23356. URL which specifies the css document to include in all cgit pages.
  23357. Defaults to @samp{"/share/cgit/cgit.css"}.
  23358. @end deftypevr
  23359. @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
  23360. Specifies a command which will be invoked to format names and email
  23361. address of committers, authors, and taggers, as represented in various
  23362. places throughout the cgit interface.
  23363. Defaults to @samp{""}.
  23364. @end deftypevr
  23365. @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
  23366. Flag which, when set to @samp{#t}, will make cgit generate a HTML
  23367. fragment suitable for embedding in other HTML pages.
  23368. Defaults to @samp{#f}.
  23369. @end deftypevr
  23370. @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
  23371. Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
  23372. commit history graph to the left of the commit messages in the
  23373. repository log page.
  23374. Defaults to @samp{#f}.
  23375. @end deftypevr
  23376. @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
  23377. Flag which, when set to @samp{#t}, allows all filter settings to be
  23378. overridden in repository-specific cgitrc files.
  23379. Defaults to @samp{#f}.
  23380. @end deftypevr
  23381. @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
  23382. Flag which, when set to @samp{#t}, allows users to follow a file in the
  23383. log view.
  23384. Defaults to @samp{#f}.
  23385. @end deftypevr
  23386. @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
  23387. If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
  23388. clones.
  23389. Defaults to @samp{#t}.
  23390. @end deftypevr
  23391. @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
  23392. Flag which, when set to @samp{#t}, will make cgit generate extra links
  23393. "summary", "commit", "tree" for each repo in the repository index.
  23394. Defaults to @samp{#f}.
  23395. @end deftypevr
  23396. @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
  23397. Flag which, when set to @samp{#t}, will make cgit display the owner of
  23398. each repo in the repository index.
  23399. Defaults to @samp{#t}.
  23400. @end deftypevr
  23401. @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
  23402. Flag which, when set to @samp{#t}, will make cgit print the number of
  23403. modified files for each commit on the repository log page.
  23404. Defaults to @samp{#f}.
  23405. @end deftypevr
  23406. @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
  23407. Flag which, when set to @samp{#t}, will make cgit print the number of
  23408. added and removed lines for each commit on the repository log page.
  23409. Defaults to @samp{#f}.
  23410. @end deftypevr
  23411. @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
  23412. Flag which, when set to @code{#t}, will make cgit display remote
  23413. branches in the summary and refs views.
  23414. Defaults to @samp{#f}.
  23415. @end deftypevr
  23416. @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
  23417. Flag which, when set to @code{1}, will make cgit use the subject of the
  23418. parent commit as link text when generating links to parent commits in
  23419. commit view.
  23420. Defaults to @samp{#f}.
  23421. @end deftypevr
  23422. @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
  23423. Flag which, when set to @samp{#t}, will make cgit use the subject of the
  23424. parent commit as link text when generating links to parent commits in
  23425. commit view.
  23426. Defaults to @samp{#f}.
  23427. @end deftypevr
  23428. @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
  23429. Flag which, when set to @samp{#t}, will make cgit generate linenumber
  23430. links for plaintext blobs printed in the tree view.
  23431. Defaults to @samp{#t}.
  23432. @end deftypevr
  23433. @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
  23434. Flag which, when set to @samp{#f}, will allow cgit to use Git config to
  23435. set any repo specific settings.
  23436. Defaults to @samp{#f}.
  23437. @end deftypevr
  23438. @deftypevr {@code{cgit-configuration} parameter} file-object favicon
  23439. URL used as link to a shortcut icon for cgit.
  23440. Defaults to @samp{"/favicon.ico"}.
  23441. @end deftypevr
  23442. @deftypevr {@code{cgit-configuration} parameter} string footer
  23443. The content of the file specified with this option will be included
  23444. verbatim at the bottom of all pages (i.e.@: it replaces the standard
  23445. "generated by..."@: message).
  23446. Defaults to @samp{""}.
  23447. @end deftypevr
  23448. @deftypevr {@code{cgit-configuration} parameter} string head-include
  23449. The content of the file specified with this option will be included
  23450. verbatim in the HTML HEAD section on all pages.
  23451. Defaults to @samp{""}.
  23452. @end deftypevr
  23453. @deftypevr {@code{cgit-configuration} parameter} string header
  23454. The content of the file specified with this option will be included
  23455. verbatim at the top of all pages.
  23456. Defaults to @samp{""}.
  23457. @end deftypevr
  23458. @deftypevr {@code{cgit-configuration} parameter} file-object include
  23459. Name of a configfile to include before the rest of the current config-
  23460. file is parsed.
  23461. Defaults to @samp{""}.
  23462. @end deftypevr
  23463. @deftypevr {@code{cgit-configuration} parameter} string index-header
  23464. The content of the file specified with this option will be included
  23465. verbatim above the repository index.
  23466. Defaults to @samp{""}.
  23467. @end deftypevr
  23468. @deftypevr {@code{cgit-configuration} parameter} string index-info
  23469. The content of the file specified with this option will be included
  23470. verbatim below the heading on the repository index page.
  23471. Defaults to @samp{""}.
  23472. @end deftypevr
  23473. @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
  23474. Flag which, if set to @samp{#t}, makes cgit print commit and tag times
  23475. in the servers timezone.
  23476. Defaults to @samp{#f}.
  23477. @end deftypevr
  23478. @deftypevr {@code{cgit-configuration} parameter} file-object logo
  23479. URL which specifies the source of an image which will be used as a logo
  23480. on all cgit pages.
  23481. Defaults to @samp{"/share/cgit/cgit.png"}.
  23482. @end deftypevr
  23483. @deftypevr {@code{cgit-configuration} parameter} string logo-link
  23484. URL loaded when clicking on the cgit logo image.
  23485. Defaults to @samp{""}.
  23486. @end deftypevr
  23487. @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
  23488. Command which will be invoked to format the Owner column of the main
  23489. page.
  23490. Defaults to @samp{""}.
  23491. @end deftypevr
  23492. @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
  23493. Number of items to display in atom feeds view.
  23494. Defaults to @samp{10}.
  23495. @end deftypevr
  23496. @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
  23497. Number of entries to list per page in "log" view.
  23498. Defaults to @samp{50}.
  23499. @end deftypevr
  23500. @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
  23501. Number of commit message characters to display in "log" view.
  23502. Defaults to @samp{80}.
  23503. @end deftypevr
  23504. @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
  23505. Specifies the number of entries to list per page on the repository index
  23506. page.
  23507. Defaults to @samp{50}.
  23508. @end deftypevr
  23509. @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
  23510. Specifies the maximum number of repo description characters to display
  23511. on the repository index page.
  23512. Defaults to @samp{80}.
  23513. @end deftypevr
  23514. @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
  23515. Specifies the maximum size of a blob to display HTML for in KBytes.
  23516. Defaults to @samp{0}.
  23517. @end deftypevr
  23518. @deftypevr {@code{cgit-configuration} parameter} string max-stats
  23519. Maximum statistics period. Valid values are @samp{week},@samp{month},
  23520. @samp{quarter} and @samp{year}.
  23521. Defaults to @samp{""}.
  23522. @end deftypevr
  23523. @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
  23524. Mimetype for the specified filename extension.
  23525. Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
  23526. "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
  23527. "image/png") (svg "image/svg+xml"))}.
  23528. @end deftypevr
  23529. @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
  23530. Specifies the file to use for automatic mimetype lookup.
  23531. Defaults to @samp{""}.
  23532. @end deftypevr
  23533. @deftypevr {@code{cgit-configuration} parameter} string module-link
  23534. Text which will be used as the formatstring for a hyperlink when a
  23535. submodule is printed in a directory listing.
  23536. Defaults to @samp{""}.
  23537. @end deftypevr
  23538. @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
  23539. If set to the value @samp{#t} caching will be disabled.
  23540. Defaults to @samp{#f}.
  23541. @end deftypevr
  23542. @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
  23543. If set to @samp{#t} showing full author email addresses will be
  23544. disabled.
  23545. Defaults to @samp{#f}.
  23546. @end deftypevr
  23547. @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
  23548. Flag which, when set to @samp{#t}, will make cgit omit the standard
  23549. header on all pages.
  23550. Defaults to @samp{#f}.
  23551. @end deftypevr
  23552. @deftypevr {@code{cgit-configuration} parameter} project-list project-list
  23553. A list of subdirectories inside of @code{repository-directory}, relative
  23554. to it, that should loaded as Git repositories. An empty list means that
  23555. all subdirectories will be loaded.
  23556. Defaults to @samp{()}.
  23557. @end deftypevr
  23558. @deftypevr {@code{cgit-configuration} parameter} file-object readme
  23559. Text which will be used as default value for @code{cgit-repo-readme}.
  23560. Defaults to @samp{""}.
  23561. @end deftypevr
  23562. @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
  23563. If set to @code{#t} and @code{repository-directory} is enabled, if any
  23564. repositories are found with a suffix of @code{.git}, this suffix will be
  23565. removed for the URL and name.
  23566. Defaults to @samp{#f}.
  23567. @end deftypevr
  23568. @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
  23569. Maximum number of files to consider when detecting renames.
  23570. Defaults to @samp{-1}.
  23571. @end deftypevr
  23572. @deftypevr {@code{cgit-configuration} parameter} string repository-sort
  23573. The way in which repositories in each section are sorted.
  23574. Defaults to @samp{""}.
  23575. @end deftypevr
  23576. @deftypevr {@code{cgit-configuration} parameter} robots-list robots
  23577. Text used as content for the @code{robots} meta-tag.
  23578. Defaults to @samp{("noindex" "nofollow")}.
  23579. @end deftypevr
  23580. @deftypevr {@code{cgit-configuration} parameter} string root-desc
  23581. Text printed below the heading on the repository index page.
  23582. Defaults to @samp{"a fast webinterface for the git dscm"}.
  23583. @end deftypevr
  23584. @deftypevr {@code{cgit-configuration} parameter} string root-readme
  23585. The content of the file specified with this option will be included
  23586. verbatim below the ``about'' link on the repository index page.
  23587. Defaults to @samp{""}.
  23588. @end deftypevr
  23589. @deftypevr {@code{cgit-configuration} parameter} string root-title
  23590. Text printed as heading on the repository index page.
  23591. Defaults to @samp{""}.
  23592. @end deftypevr
  23593. @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
  23594. If set to @samp{#t} and repository-directory is enabled,
  23595. repository-directory will recurse into directories whose name starts
  23596. with a period. Otherwise, repository-directory will stay away from such
  23597. directories, considered as ``hidden''. Note that this does not apply to
  23598. the @file{.git} directory in non-bare repos.
  23599. Defaults to @samp{#f}.
  23600. @end deftypevr
  23601. @deftypevr {@code{cgit-configuration} parameter} list snapshots
  23602. Text which specifies the default set of snapshot formats that cgit
  23603. generates links for.
  23604. Defaults to @samp{()}.
  23605. @end deftypevr
  23606. @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
  23607. Name of the directory to scan for repositories (represents
  23608. @code{scan-path}).
  23609. Defaults to @samp{"/srv/git"}.
  23610. @end deftypevr
  23611. @deftypevr {@code{cgit-configuration} parameter} string section
  23612. The name of the current repository section - all repositories defined
  23613. after this option will inherit the current section name.
  23614. Defaults to @samp{""}.
  23615. @end deftypevr
  23616. @deftypevr {@code{cgit-configuration} parameter} string section-sort
  23617. Flag which, when set to @samp{1}, will sort the sections on the
  23618. repository listing by name.
  23619. Defaults to @samp{""}.
  23620. @end deftypevr
  23621. @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
  23622. A number which, if defined prior to repository-directory, specifies how
  23623. many path elements from each repo path to use as a default section name.
  23624. Defaults to @samp{0}.
  23625. @end deftypevr
  23626. @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
  23627. If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
  23628. default.
  23629. Defaults to @samp{#f}.
  23630. @end deftypevr
  23631. @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
  23632. Specifies a command which will be invoked to format plaintext blobs in
  23633. the tree view.
  23634. Defaults to @samp{""}.
  23635. @end deftypevr
  23636. @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
  23637. Specifies the number of branches to display in the repository ``summary''
  23638. view.
  23639. Defaults to @samp{10}.
  23640. @end deftypevr
  23641. @deftypevr {@code{cgit-configuration} parameter} integer summary-log
  23642. Specifies the number of log entries to display in the repository
  23643. ``summary'' view.
  23644. Defaults to @samp{10}.
  23645. @end deftypevr
  23646. @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
  23647. Specifies the number of tags to display in the repository ``summary''
  23648. view.
  23649. Defaults to @samp{10}.
  23650. @end deftypevr
  23651. @deftypevr {@code{cgit-configuration} parameter} string strict-export
  23652. Filename which, if specified, needs to be present within the repository
  23653. for cgit to allow access to that repository.
  23654. Defaults to @samp{""}.
  23655. @end deftypevr
  23656. @deftypevr {@code{cgit-configuration} parameter} string virtual-root
  23657. URL which, if specified, will be used as root for all cgit links.
  23658. Defaults to @samp{"/"}.
  23659. @end deftypevr
  23660. @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
  23661. A list of @dfn{cgit-repo} records to use with config.
  23662. Defaults to @samp{()}.
  23663. Available @code{repository-cgit-configuration} fields are:
  23664. @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
  23665. A mask of snapshot formats for this repo that cgit generates links for,
  23666. restricted by the global @code{snapshots} setting.
  23667. Defaults to @samp{()}.
  23668. @end deftypevr
  23669. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
  23670. Override the default @code{source-filter}.
  23671. Defaults to @samp{""}.
  23672. @end deftypevr
  23673. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
  23674. The relative URL used to access the repository.
  23675. Defaults to @samp{""}.
  23676. @end deftypevr
  23677. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
  23678. Override the default @code{about-filter}.
  23679. Defaults to @samp{""}.
  23680. @end deftypevr
  23681. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
  23682. Flag which, when set to @samp{age}, enables date ordering in the branch
  23683. ref list, and when set to @samp{name} enables ordering by branch name.
  23684. Defaults to @samp{""}.
  23685. @end deftypevr
  23686. @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
  23687. A list of URLs which can be used to clone repo.
  23688. Defaults to @samp{()}.
  23689. @end deftypevr
  23690. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
  23691. Override the default @code{commit-filter}.
  23692. Defaults to @samp{""}.
  23693. @end deftypevr
  23694. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
  23695. Flag which, when set to @samp{date}, enables strict date ordering in the
  23696. commit log, and when set to @samp{topo} enables strict topological
  23697. ordering.
  23698. Defaults to @samp{""}.
  23699. @end deftypevr
  23700. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
  23701. The name of the default branch for this repository. If no such branch
  23702. exists in the repository, the first branch name (when sorted) is used as
  23703. default instead. By default branch pointed to by HEAD, or ``master'' if
  23704. there is no suitable HEAD.
  23705. Defaults to @samp{""}.
  23706. @end deftypevr
  23707. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
  23708. The value to show as repository description.
  23709. Defaults to @samp{""}.
  23710. @end deftypevr
  23711. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
  23712. The value to show as repository homepage.
  23713. Defaults to @samp{""}.
  23714. @end deftypevr
  23715. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
  23716. Override the default @code{email-filter}.
  23717. Defaults to @samp{""}.
  23718. @end deftypevr
  23719. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
  23720. A flag which can be used to disable the global setting
  23721. @code{enable-commit-graph?}.
  23722. Defaults to @samp{disabled}.
  23723. @end deftypevr
  23724. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
  23725. A flag which can be used to disable the global setting
  23726. @code{enable-log-filecount?}.
  23727. Defaults to @samp{disabled}.
  23728. @end deftypevr
  23729. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
  23730. A flag which can be used to disable the global setting
  23731. @code{enable-log-linecount?}.
  23732. Defaults to @samp{disabled}.
  23733. @end deftypevr
  23734. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
  23735. Flag which, when set to @code{#t}, will make cgit display remote
  23736. branches in the summary and refs views.
  23737. Defaults to @samp{disabled}.
  23738. @end deftypevr
  23739. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
  23740. A flag which can be used to override the global setting
  23741. @code{enable-subject-links?}.
  23742. Defaults to @samp{disabled}.
  23743. @end deftypevr
  23744. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
  23745. A flag which can be used to override the global setting
  23746. @code{enable-html-serving?}.
  23747. Defaults to @samp{disabled}.
  23748. @end deftypevr
  23749. @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
  23750. Flag which, when set to @code{#t}, hides the repository from the
  23751. repository index.
  23752. Defaults to @samp{#f}.
  23753. @end deftypevr
  23754. @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
  23755. Flag which, when set to @samp{#t}, ignores the repository.
  23756. Defaults to @samp{#f}.
  23757. @end deftypevr
  23758. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
  23759. URL which specifies the source of an image which will be used as a logo
  23760. on this repo’s pages.
  23761. Defaults to @samp{""}.
  23762. @end deftypevr
  23763. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
  23764. URL loaded when clicking on the cgit logo image.
  23765. Defaults to @samp{""}.
  23766. @end deftypevr
  23767. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
  23768. Override the default @code{owner-filter}.
  23769. Defaults to @samp{""}.
  23770. @end deftypevr
  23771. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
  23772. Text which will be used as the formatstring for a hyperlink when a
  23773. submodule is printed in a directory listing. The arguments for the
  23774. formatstring are the path and SHA1 of the submodule commit.
  23775. Defaults to @samp{""}.
  23776. @end deftypevr
  23777. @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
  23778. Text which will be used as the formatstring for a hyperlink when a
  23779. submodule with the specified subdirectory path is printed in a directory
  23780. listing.
  23781. Defaults to @samp{()}.
  23782. @end deftypevr
  23783. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
  23784. Override the default maximum statistics period.
  23785. Defaults to @samp{""}.
  23786. @end deftypevr
  23787. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
  23788. The value to show as repository name.
  23789. Defaults to @samp{""}.
  23790. @end deftypevr
  23791. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
  23792. A value used to identify the owner of the repository.
  23793. Defaults to @samp{""}.
  23794. @end deftypevr
  23795. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
  23796. An absolute path to the repository directory.
  23797. Defaults to @samp{""}.
  23798. @end deftypevr
  23799. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
  23800. A path (relative to repo) which specifies a file to include verbatim as
  23801. the ``About'' page for this repo.
  23802. Defaults to @samp{""}.
  23803. @end deftypevr
  23804. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
  23805. The name of the current repository section - all repositories defined
  23806. after this option will inherit the current section name.
  23807. Defaults to @samp{""}.
  23808. @end deftypevr
  23809. @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
  23810. Extra options will be appended to cgitrc file.
  23811. Defaults to @samp{()}.
  23812. @end deftypevr
  23813. @end deftypevr
  23814. @deftypevr {@code{cgit-configuration} parameter} list extra-options
  23815. Extra options will be appended to cgitrc file.
  23816. Defaults to @samp{()}.
  23817. @end deftypevr
  23818. @c %end of fragment
  23819. However, it could be that you just want to get a @code{cgitrc} up and
  23820. running. In that case, you can pass an @code{opaque-cgit-configuration}
  23821. as a record to @code{cgit-service-type}. As its name indicates, an
  23822. opaque configuration does not have easy reflective capabilities.
  23823. Available @code{opaque-cgit-configuration} fields are:
  23824. @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
  23825. The cgit package.
  23826. @end deftypevr
  23827. @deftypevr {@code{opaque-cgit-configuration} parameter} string string
  23828. The contents of the @code{cgitrc}, as a string.
  23829. @end deftypevr
  23830. For example, if your @code{cgitrc} is just the empty string, you
  23831. could instantiate a cgit service like this:
  23832. @lisp
  23833. (service cgit-service-type
  23834. (opaque-cgit-configuration
  23835. (cgitrc "")))
  23836. @end lisp
  23837. @subsubheading Gitolite Service
  23838. @cindex Gitolite service
  23839. @cindex Git, hosting
  23840. @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
  23841. repositories on a central server.
  23842. Gitolite can handle multiple repositories and users, and supports flexible
  23843. configuration of the permissions for the users on the repositories.
  23844. The following example will configure Gitolite using the default @code{git}
  23845. user, and the provided SSH public key.
  23846. @lisp
  23847. (service gitolite-service-type
  23848. (gitolite-configuration
  23849. (admin-pubkey (plain-file
  23850. "yourname.pub"
  23851. "ssh-rsa AAAA... guix@@example.com"))))
  23852. @end lisp
  23853. Gitolite is configured through a special admin repository which you can clone,
  23854. for example, if you setup Gitolite on @code{example.com}, you would run the
  23855. following command to clone the admin repository.
  23856. @example
  23857. git clone git@@example.com:gitolite-admin
  23858. @end example
  23859. When the Gitolite service is activated, the provided @code{admin-pubkey} will
  23860. be inserted in to the @file{keydir} directory in the gitolite-admin
  23861. repository. If this results in a change in the repository, it will be
  23862. committed using the message ``gitolite setup by GNU Guix''.
  23863. @deftp {Data Type} gitolite-configuration
  23864. Data type representing the configuration for @code{gitolite-service-type}.
  23865. @table @asis
  23866. @item @code{package} (default: @var{gitolite})
  23867. Gitolite package to use.
  23868. @item @code{user} (default: @var{git})
  23869. User to use for Gitolite. This will be user that you use when accessing
  23870. Gitolite over SSH.
  23871. @item @code{group} (default: @var{git})
  23872. Group to use for Gitolite.
  23873. @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
  23874. Directory in which to store the Gitolite configuration and repositories.
  23875. @item @code{rc-file} (default: @var{(gitolite-rc-file)})
  23876. A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
  23877. representing the configuration for Gitolite.
  23878. @item @code{admin-pubkey} (default: @var{#f})
  23879. A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
  23880. setup Gitolite. This will be inserted in to the @file{keydir} directory
  23881. within the gitolite-admin repository.
  23882. To specify the SSH key as a string, use the @code{plain-file} function.
  23883. @lisp
  23884. (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
  23885. @end lisp
  23886. @end table
  23887. @end deftp
  23888. @deftp {Data Type} gitolite-rc-file
  23889. Data type representing the Gitolite RC file.
  23890. @table @asis
  23891. @item @code{umask} (default: @code{#o0077})
  23892. This controls the permissions Gitolite sets on the repositories and their
  23893. contents.
  23894. A value like @code{#o0027} will give read access to the group used by Gitolite
  23895. (by default: @code{git}). This is necessary when using Gitolite with software
  23896. like cgit or gitweb.
  23897. @item @code{git-config-keys} (default: @code{""})
  23898. Gitolite allows you to set git config values using the @samp{config}
  23899. keyword. This setting allows control over the config keys to accept.
  23900. @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
  23901. Set the role names allowed to be used by users running the perms command.
  23902. @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
  23903. This setting controls the commands and features to enable within Gitolite.
  23904. @end table
  23905. @end deftp
  23906. @node Game Services
  23907. @subsection Game Services
  23908. @subsubheading The Battle for Wesnoth Service
  23909. @cindex wesnothd
  23910. @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
  23911. based tactical strategy game, with several single player campaigns, and
  23912. multiplayer games (both networked and local).
  23913. @defvar {Scheme Variable} wesnothd-service-type
  23914. Service type for the wesnothd service. Its value must be a
  23915. @code{wesnothd-configuration} object. To run wesnothd in the default
  23916. configuration, instantiate it as:
  23917. @lisp
  23918. (service wesnothd-service-type)
  23919. @end lisp
  23920. @end defvar
  23921. @deftp {Data Type} wesnothd-configuration
  23922. Data type representing the configuration of @command{wesnothd}.
  23923. @table @asis
  23924. @item @code{package} (default: @code{wesnoth-server})
  23925. The wesnoth server package to use.
  23926. @item @code{port} (default: @code{15000})
  23927. The port to bind the server to.
  23928. @end table
  23929. @end deftp
  23930. @node PAM Mount Service
  23931. @subsection PAM Mount Service
  23932. @cindex pam-mount
  23933. The @code{(gnu services pam-mount)} module provides a service allowing
  23934. users to mount volumes when they log in. It should be able to mount any
  23935. volume format supported by the system.
  23936. @defvar {Scheme Variable} pam-mount-service-type
  23937. Service type for PAM Mount support.
  23938. @end defvar
  23939. @deftp {Data Type} pam-mount-configuration
  23940. Data type representing the configuration of PAM Mount.
  23941. It takes the following parameters:
  23942. @table @asis
  23943. @item @code{rules}
  23944. The configuration rules that will be used to generate
  23945. @file{/etc/security/pam_mount.conf.xml}.
  23946. The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
  23947. Guile Reference Manual}), and the default ones don't mount anything for
  23948. anyone at login:
  23949. @lisp
  23950. `((debug (@@ (enable "0")))
  23951. (mntoptions (@@ (allow ,(string-join
  23952. '("nosuid" "nodev" "loop"
  23953. "encryption" "fsck" "nonempty"
  23954. "allow_root" "allow_other")
  23955. ","))))
  23956. (mntoptions (@@ (require "nosuid,nodev")))
  23957. (logout (@@ (wait "0")
  23958. (hup "0")
  23959. (term "no")
  23960. (kill "no")))
  23961. (mkmountpoint (@@ (enable "1")
  23962. (remove "true"))))
  23963. @end lisp
  23964. Some @code{volume} elements must be added to automatically mount volumes
  23965. at login. Here's an example allowing the user @code{alice} to mount her
  23966. encrypted @env{HOME} directory and allowing the user @code{bob} to mount
  23967. the partition where he stores his data:
  23968. @lisp
  23969. (define pam-mount-rules
  23970. `((debug (@@ (enable "0")))
  23971. (volume (@@ (user "alice")
  23972. (fstype "crypt")
  23973. (path "/dev/sda2")
  23974. (mountpoint "/home/alice")))
  23975. (volume (@@ (user "bob")
  23976. (fstype "auto")
  23977. (path "/dev/sdb3")
  23978. (mountpoint "/home/bob/data")
  23979. (options "defaults,autodefrag,compress")))
  23980. (mntoptions (@@ (allow ,(string-join
  23981. '("nosuid" "nodev" "loop"
  23982. "encryption" "fsck" "nonempty"
  23983. "allow_root" "allow_other")
  23984. ","))))
  23985. (mntoptions (@@ (require "nosuid,nodev")))
  23986. (logout (@@ (wait "0")
  23987. (hup "0")
  23988. (term "no")
  23989. (kill "no")))
  23990. (mkmountpoint (@@ (enable "1")
  23991. (remove "true")))))
  23992. (service pam-mount-service-type
  23993. (pam-mount-configuration
  23994. (rules pam-mount-rules)))
  23995. @end lisp
  23996. The complete list of possible options can be found in the man page for
  23997. @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
  23998. @end table
  23999. @end deftp
  24000. @node Guix Services
  24001. @subsection Guix Services
  24002. @subsubheading Guix Build Coordinator
  24003. The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
  24004. Coordinator} aids in distributing derivation builds among machines
  24005. running an @dfn{agent}. The build daemon is still used to build the
  24006. derivations, but the Guix Build Coordinator manages allocating builds
  24007. and working with the results.
  24008. @quotation Note
  24009. This service is considered experimental. Configuration options may be
  24010. changed in a backwards-incompatible manner, and not all features have
  24011. been thorougly tested.
  24012. @end quotation
  24013. The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
  24014. more connected @dfn{agent} processes. The coordinator process handles
  24015. clients submitting builds, and allocating builds to agents. The agent
  24016. processes talk to a build daemon to actually perform the builds, then
  24017. send the results back to the coordinator.
  24018. There is a script to run the coordinator component of the Guix Build
  24019. Coordinator, but the Guix service uses a custom Guile script instead, to
  24020. provide better integration with G-expressions used in the configuration.
  24021. @defvar {Scheme Variable} guix-build-coordinator-service-type
  24022. Service type for the Guix Build Coordinator. Its value must be a
  24023. @code{guix-build-coordinator-configuration} object.
  24024. @end defvar
  24025. @deftp {Data Type} guix-build-coordinator-configuration
  24026. Data type representing the configuration of the Guix Build Coordinator.
  24027. @table @asis
  24028. @item @code{package} (default: @code{guix-build-coordinator})
  24029. The Guix Build Coordinator package to use.
  24030. @item @code{user} (default: @code{"guix-build-coordinator"})
  24031. The system user to run the service as.
  24032. @item @code{group} (default: @code{"guix-build-coordinator"})
  24033. The system group to run the service as.
  24034. @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
  24035. The URI to use for the database.
  24036. @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
  24037. The URI describing how to listen to requests from agent processes.
  24038. @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
  24039. The URI describing how to listen to requests from clients. The client
  24040. API allows submitting builds and currently isn't authenticated, so take
  24041. care when configuring this value.
  24042. @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
  24043. A G-expression for the allocation strategy to be used. This is a
  24044. procedure that takes the datastore as an argument and populates the
  24045. allocation plan in the database.
  24046. @item @code{hooks} (default: @var{'()})
  24047. An association list of hooks. These provide a way to execute arbitrary
  24048. code upon certain events, like a build result being processed.
  24049. @item @code{guile} (default: @code{guile-3.0-latest})
  24050. The Guile package with which to run the Guix Build Coordinator.
  24051. @end table
  24052. @end deftp
  24053. @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
  24054. Service type for a Guix Build Coordinator agent. Its value must be a
  24055. @code{guix-build-coordinator-agent-configuration} object.
  24056. @end defvar
  24057. @deftp {Data Type} guix-build-coordinator-agent-configuration
  24058. Data type representing the configuration a Guix Build Coordinator agent.
  24059. @table @asis
  24060. @item @code{package} (default: @code{guix-build-coordinator})
  24061. The Guix Build Coordinator package to use.
  24062. @item @code{user} (default: @code{"guix-build-coordinator-agent"})
  24063. The system user to run the service as.
  24064. @item @code{coordinator} (default: @code{"http://localhost:8745"})
  24065. The URI to use when connecting to the coordinator.
  24066. @item @code{authentication}
  24067. Record describing how this agent should authenticate with the
  24068. coordinator. Possible record types are described below.
  24069. @item @code{systems} (default: @code{#f})
  24070. The systems for which this agent should fetch builds. The agent process
  24071. will use the current system it's running on as the default.
  24072. @item @code{max-parallel-builds} (default: @code{1})
  24073. The number of builds to perform in parallel.
  24074. @item @code{derivation-substitute-urls} (default: @code{#f})
  24075. URLs from which to attempt to fetch substitutes for derivations, if the
  24076. derivations aren't already available.
  24077. @item @code{non-derivation-substitute-urls} (default: @code{#f})
  24078. URLs from which to attempt to fetch substitutes for build inputs, if the
  24079. input store items aren't already available.
  24080. @end table
  24081. @end deftp
  24082. @deftp {Data Type} guix-build-coordinator-agent-password-auth
  24083. Data type representing an agent authenticating with a coordinator via a
  24084. UUID and password.
  24085. @table @asis
  24086. @item @code{uuid}
  24087. The UUID of the agent. This should be generated by the coordinator
  24088. process, stored in the coordinator database, and used by the intended
  24089. agent.
  24090. @item @code{password}
  24091. The password to use when connecting to the coordinator.
  24092. @end table
  24093. @end deftp
  24094. @deftp {Data Type} guix-build-coordinator-agent-password-file-auth
  24095. Data type representing an agent authenticating with a coordinator via a
  24096. UUID and password read from a file.
  24097. @table @asis
  24098. @item @code{uuid}
  24099. The UUID of the agent. This should be generated by the coordinator
  24100. process, stored in the coordinator database, and used by the intended
  24101. agent.
  24102. @item @code{password-file}
  24103. A file containing the password to use when connecting to the
  24104. coordinator.
  24105. @end table
  24106. @end deftp
  24107. @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth
  24108. Data type representing an agent authenticating with a coordinator via a
  24109. dyanmic auth token and agent name.
  24110. @table @asis
  24111. @item @code{agent-name}
  24112. Name of an agent, this is used to match up to an existing entry in the
  24113. database if there is one. When no existing entry is found, a new entry
  24114. is automatically added.
  24115. @item @code{token}
  24116. Dynamic auth token, this is created and stored in the coordinator
  24117. database, and is used by the agent to authenticate.
  24118. @end table
  24119. @end deftp
  24120. @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth-with-file
  24121. Data type representing an agent authenticating with a coordinator via a
  24122. dyanmic auth token read from a file and agent name.
  24123. @table @asis
  24124. @item @code{agent-name}
  24125. Name of an agent, this is used to match up to an existing entry in the
  24126. database if there is one. When no existing entry is found, a new entry
  24127. is automatically added.
  24128. @item @code{token-file}
  24129. File containing the dynamic auth token, this is created and stored in
  24130. the coordinator database, and is used by the agent to authenticate.
  24131. @end table
  24132. @end deftp
  24133. The Guix Build Coordinator package contains a script to query an
  24134. instance of the Guix Data Service for derivations to build, and then
  24135. submit builds for those derivations to the coordinator. The service
  24136. type below assists in running this script. This is an additional tool
  24137. that may be useful when building derivations contained within an
  24138. instance of the Guix Data Service.
  24139. @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
  24140. Service type for the
  24141. guix-build-coordinator-queue-builds-from-guix-data-service script. Its
  24142. value must be a @code{guix-build-coordinator-queue-builds-configuration}
  24143. object.
  24144. @end defvar
  24145. @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
  24146. Data type representing the options to the queue builds from guix data
  24147. service script.
  24148. @table @asis
  24149. @item @code{package} (default: @code{guix-build-coordinator})
  24150. The Guix Build Coordinator package to use.
  24151. @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
  24152. The system user to run the service as.
  24153. @item @code{coordinator} (default: @code{"http://localhost:8745"})
  24154. The URI to use when connecting to the coordinator.
  24155. @item @code{systems} (default: @code{#f})
  24156. The systems for which to fetch derivations to build.
  24157. @item @code{systems-and-targets} (default: @code{#f})
  24158. An association list of system and target pairs for which to fetch
  24159. derivations to build.
  24160. @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
  24161. The Guix Data Service instance from which to query to find out about
  24162. derivations to build.
  24163. @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
  24164. A file to record which commits have been processed, to avoid needlessly
  24165. processing them again if the service is restarted.
  24166. @end table
  24167. @end deftp
  24168. @subsubheading Guix Data Service
  24169. The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
  24170. and provides data about GNU Guix. This includes information about
  24171. packages, derivations and lint warnings.
  24172. The data is stored in a PostgreSQL database, and available through a web
  24173. interface.
  24174. @defvar {Scheme Variable} guix-data-service-type
  24175. Service type for the Guix Data Service. Its value must be a
  24176. @code{guix-data-service-configuration} object. The service optionally
  24177. extends the getmail service, as the guix-commits mailing list is used to
  24178. find out about changes in the Guix git repository.
  24179. @end defvar
  24180. @deftp {Data Type} guix-data-service-configuration
  24181. Data type representing the configuration of the Guix Data Service.
  24182. @table @asis
  24183. @item @code{package} (default: @code{guix-data-service})
  24184. The Guix Data Service package to use.
  24185. @item @code{user} (default: @code{"guix-data-service"})
  24186. The system user to run the service as.
  24187. @item @code{group} (default: @code{"guix-data-service"})
  24188. The system group to run the service as.
  24189. @item @code{port} (default: @code{8765})
  24190. The port to bind the web service to.
  24191. @item @code{host} (default: @code{"127.0.0.1"})
  24192. The host to bind the web service to.
  24193. @item @code{getmail-idle-mailboxes} (default: @code{#f})
  24194. If set, this is the list of mailboxes that the getmail service will be
  24195. configured to listen to.
  24196. @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
  24197. If set, this is the @code{getmail-retriever-configuration} object with
  24198. which to configure getmail to fetch mail from the guix-commits mailing
  24199. list.
  24200. @item @code{extra-options} (default: @var{'()})
  24201. Extra command line options for @code{guix-data-service}.
  24202. @item @code{extra-process-jobs-options} (default: @var{'()})
  24203. Extra command line options for @code{guix-data-service-process-jobs}.
  24204. @end table
  24205. @end deftp
  24206. @node Linux Services
  24207. @subsection Linux Services
  24208. @cindex oom
  24209. @cindex out of memory killer
  24210. @cindex earlyoom
  24211. @cindex early out of memory daemon
  24212. @subsubheading Early OOM Service
  24213. @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
  24214. Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
  24215. space and provides a more responsive and configurable alternative to the
  24216. in-kernel OOM killer. It is useful to prevent the system from becoming
  24217. unresponsive when it runs out of memory.
  24218. @deffn {Scheme Variable} earlyoom-service-type
  24219. The service type for running @command{earlyoom}, the Early OOM daemon.
  24220. Its value must be a @code{earlyoom-configuration} object, described
  24221. below. The service can be instantiated in its default configuration
  24222. with:
  24223. @lisp
  24224. (service earlyoom-service-type)
  24225. @end lisp
  24226. @end deffn
  24227. @deftp {Data Type} earlyoom-configuration
  24228. This is the configuration record for the @code{earlyoom-service-type}.
  24229. @table @asis
  24230. @item @code{earlyoom} (default: @var{earlyoom})
  24231. The Earlyoom package to use.
  24232. @item @code{minimum-available-memory} (default: @code{10})
  24233. The threshold for the minimum @emph{available} memory, in percentages.
  24234. @item @code{minimum-free-swap} (default: @code{10})
  24235. The threshold for the minimum free swap memory, in percentages.
  24236. @item @code{prefer-regexp} (default: @code{#f})
  24237. A regular expression (as a string) to match the names of the processes
  24238. that should be preferably killed.
  24239. @item @code{avoid-regexp} (default: @code{#f})
  24240. A regular expression (as a string) to match the names of the processes
  24241. that should @emph{not} be killed.
  24242. @item @code{memory-report-interval} (default: @code{0})
  24243. The interval in seconds at which a memory report is printed. It is
  24244. disabled by default.
  24245. @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
  24246. A boolean indicating whether the positive adjustments set in
  24247. @file{/proc/*/oom_score_adj} should be ignored.
  24248. @item @code{show-debug-messages?} (default: @code{#f})
  24249. A boolean indicating whether debug messages should be printed. The logs
  24250. are saved at @file{/var/log/earlyoom.log}.
  24251. @item @code{send-notification-command} (default: @code{#f})
  24252. This can be used to provide a custom command used for sending
  24253. notifications.
  24254. @end table
  24255. @end deftp
  24256. @cindex modprobe
  24257. @cindex kernel module loader
  24258. @subsubheading Kernel Module Loader Service
  24259. The kernel module loader service allows one to load loadable kernel
  24260. modules at boot. This is especially useful for modules that don't
  24261. autoload and need to be manually loaded, as it's the case with
  24262. @code{ddcci}.
  24263. @deffn {Scheme Variable} kernel-module-loader-service-type
  24264. The service type for loading loadable kernel modules at boot with
  24265. @command{modprobe}. Its value must be a list of strings representing
  24266. module names. For example loading the drivers provided by
  24267. @code{ddcci-driver-linux}, in debugging mode by passing some module
  24268. parameters, can be done as follow:
  24269. @lisp
  24270. (use-modules (gnu) (gnu services))
  24271. (use-package-modules linux)
  24272. (use-service-modules linux)
  24273. (define ddcci-config
  24274. (plain-file "ddcci.conf"
  24275. "options ddcci dyndbg delay=120"))
  24276. (operating-system
  24277. ...
  24278. (services (cons* (service kernel-module-loader-service-type
  24279. '("ddcci" "ddcci_backlight"))
  24280. (simple-service 'ddcci-config etc-service-type
  24281. (list `("modprobe.d/ddcci.conf"
  24282. ,ddcci-config)))
  24283. %base-services))
  24284. (kernel-loadable-modules (list ddcci-driver-linux)))
  24285. @end lisp
  24286. @end deffn
  24287. @cindex zram
  24288. @cindex compressed swap
  24289. @cindex Compressed RAM-based block devices
  24290. @subsubheading Zram Device Service
  24291. The Zram device service provides a compressed swap device in system
  24292. memory. The Linux Kernel documentation has more information about
  24293. @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
  24294. devices.
  24295. @deffn {Scheme Variable} zram-device-service-type
  24296. This service creates the zram block device, formats it as swap and
  24297. enables it as a swap device. The service's value is a
  24298. @code{zram-device-configuration} record.
  24299. @deftp {Data Type} zram-device-configuration
  24300. This is the data type representing the configuration for the zram-device
  24301. service.
  24302. @table @asis
  24303. @item @code{size} (default @code{"1G"})
  24304. This is the amount of space you wish to provide for the zram device. It
  24305. accepts a string and can be a number of bytes or use a suffix, eg.:
  24306. @code{"512M"} or @code{1024000}.
  24307. @item @code{compression-algorithm} (default @code{'lzo})
  24308. This is the compression algorithm you wish to use. It is difficult to
  24309. list all the possible compression options, but common ones supported by
  24310. Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
  24311. @item @code{memory-limit} (default @code{0})
  24312. This is the maximum amount of memory which the zram device can use.
  24313. Setting it to '0' disables the limit. While it is generally expected
  24314. that compression will be 2:1, it is possible that uncompressable data
  24315. can be written to swap and this is a method to limit how much memory can
  24316. be used. It accepts a string and can be a number of bytes or use a
  24317. suffix, eg.: @code{"2G"}.
  24318. @item @code{priority} (default @code{-1})
  24319. This is the priority of the swap device created from the zram device.
  24320. @code{swapon} accepts values between -1 and 32767, with higher values
  24321. indicating higher priority. Higher priority swap will generally be used
  24322. first.
  24323. @end table
  24324. @end deftp
  24325. @end deffn
  24326. @node Hurd Services
  24327. @subsection Hurd Services
  24328. @defvr {Scheme Variable} hurd-console-service-type
  24329. This service starts the fancy @code{VGA} console client on the Hurd.
  24330. The service's value is a @code{hurd-console-configuration} record.
  24331. @end defvr
  24332. @deftp {Data Type} hurd-console-configuration
  24333. This is the data type representing the configuration for the
  24334. hurd-console-service.
  24335. @table @asis
  24336. @item @code{hurd} (default: @var{hurd})
  24337. The Hurd package to use.
  24338. @end table
  24339. @end deftp
  24340. @defvr {Scheme Variable} hurd-getty-service-type
  24341. This service starts a tty using the Hurd @code{getty} program.
  24342. The service's value is a @code{hurd-getty-configuration} record.
  24343. @end defvr
  24344. @deftp {Data Type} hurd-getty-configuration
  24345. This is the data type representing the configuration for the
  24346. hurd-getty-service.
  24347. @table @asis
  24348. @item @code{hurd} (default: @var{hurd})
  24349. The Hurd package to use.
  24350. @item @code{tty}
  24351. The name of the console this Getty runs on---e.g., @code{"tty1"}.
  24352. @item @code{baud-rate} (default: @code{38400})
  24353. An integer specifying the baud rate of the tty.
  24354. @end table
  24355. @end deftp
  24356. @node Miscellaneous Services
  24357. @subsection Miscellaneous Services
  24358. @cindex fingerprint
  24359. @subsubheading Fingerprint Service
  24360. The @code{(gnu services authentication)} module provides a DBus service to
  24361. read and identify fingerprints via a fingerprint sensor.
  24362. @defvr {Scheme Variable} fprintd-service-type
  24363. The service type for @command{fprintd}, which provides the fingerprint
  24364. reading capability.
  24365. @lisp
  24366. (service fprintd-service-type)
  24367. @end lisp
  24368. @end defvr
  24369. @cindex sysctl
  24370. @subsubheading System Control Service
  24371. The @code{(gnu services sysctl)} provides a service to configure kernel
  24372. parameters at boot.
  24373. @defvr {Scheme Variable} sysctl-service-type
  24374. The service type for @command{sysctl}, which modifies kernel parameters
  24375. under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
  24376. instantiated as:
  24377. @lisp
  24378. (service sysctl-service-type
  24379. (sysctl-configuration
  24380. (settings '(("net.ipv4.ip_forward" . "1")))))
  24381. @end lisp
  24382. Since @code{sysctl-service-type} is used in the default lists of
  24383. services, @code{%base-services} and @code{%desktop-services}, you can
  24384. use @code{modify-services} to change its configuration and add the
  24385. kernel parameters that you want (@pxref{Service Reference,
  24386. @code{modify-services}}).
  24387. @lisp
  24388. (modify-services %base-services
  24389. (sysctl-service-type config =>
  24390. (sysctl-configuration
  24391. (settings (append '(("net.ipv4.ip_forward" . "1"))
  24392. %default-sysctl-settings)))))
  24393. @end lisp
  24394. @end defvr
  24395. @deftp {Data Type} sysctl-configuration
  24396. The data type representing the configuration of @command{sysctl}.
  24397. @table @asis
  24398. @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
  24399. The @command{sysctl} executable to use.
  24400. @item @code{settings} (default: @code{%default-sysctl-settings})
  24401. An association list specifies kernel parameters and their values.
  24402. @end table
  24403. @end deftp
  24404. @defvr {Scheme Variable} %default-sysctl-settings
  24405. An association list specifying the default @command{sysctl} parameters
  24406. on Guix System.
  24407. @end defvr
  24408. @cindex pcscd
  24409. @subsubheading PC/SC Smart Card Daemon Service
  24410. The @code{(gnu services security-token)} module provides the following service
  24411. to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
  24412. daemon program for pcsc-lite and the MuscleCard framework. It is a resource
  24413. manager that coordinates communications with smart card readers, smart cards
  24414. and cryptographic tokens that are connected to the system.
  24415. @defvr {Scheme Variable} pcscd-service-type
  24416. Service type for the @command{pcscd} service. Its value must be a
  24417. @code{pcscd-configuration} object. To run pcscd in the default
  24418. configuration, instantiate it as:
  24419. @lisp
  24420. (service pcscd-service-type)
  24421. @end lisp
  24422. @end defvr
  24423. @deftp {Data Type} pcscd-configuration
  24424. The data type representing the configuration of @command{pcscd}.
  24425. @table @asis
  24426. @item @code{pcsc-lite} (default: @code{pcsc-lite})
  24427. The pcsc-lite package that provides pcscd.
  24428. @item @code{usb-drivers} (default: @code{(list ccid)})
  24429. List of packages that provide USB drivers to pcscd. Drivers are expected to be
  24430. under @file{pcsc/drivers} in the store directory of the package.
  24431. @end table
  24432. @end deftp
  24433. @cindex lirc
  24434. @subsubheading Lirc Service
  24435. The @code{(gnu services lirc)} module provides the following service.
  24436. @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
  24437. [#:device #f] [#:driver #f] [#:config-file #f] @
  24438. [#:extra-options '()]
  24439. Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
  24440. decodes infrared signals from remote controls.
  24441. Optionally, @var{device}, @var{driver} and @var{config-file}
  24442. (configuration file name) may be specified. See @command{lircd} manual
  24443. for details.
  24444. Finally, @var{extra-options} is a list of additional command-line options
  24445. passed to @command{lircd}.
  24446. @end deffn
  24447. @cindex spice
  24448. @subsubheading Spice Service
  24449. The @code{(gnu services spice)} module provides the following service.
  24450. @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
  24451. Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
  24452. that enables sharing the clipboard with a vm and setting the guest display
  24453. resolution when the graphical console window resizes.
  24454. @end deffn
  24455. @cindex inputattach
  24456. @subsubheading inputattach Service
  24457. @cindex tablet input, for Xorg
  24458. @cindex touchscreen input, for Xorg
  24459. The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
  24460. use input devices such as Wacom tablets, touchscreens, or joysticks with the
  24461. Xorg display server.
  24462. @deffn {Scheme Variable} inputattach-service-type
  24463. Type of a service that runs @command{inputattach} on a device and
  24464. dispatches events from it.
  24465. @end deffn
  24466. @deftp {Data Type} inputattach-configuration
  24467. @table @asis
  24468. @item @code{device-type} (default: @code{"wacom"})
  24469. The type of device to connect to. Run @command{inputattach --help}, from the
  24470. @code{inputattach} package, to see the list of supported device types.
  24471. @item @code{device} (default: @code{"/dev/ttyS0"})
  24472. The device file to connect to the device.
  24473. @item @code{baud-rate} (default: @code{#f})
  24474. Baud rate to use for the serial connection.
  24475. Should be a number or @code{#f}.
  24476. @item @code{log-file} (default: @code{#f})
  24477. If true, this must be the name of a file to log messages to.
  24478. @end table
  24479. @end deftp
  24480. @subsubheading Dictionary Service
  24481. @cindex dictionary
  24482. The @code{(gnu services dict)} module provides the following service:
  24483. @defvr {Scheme Variable} dicod-service-type
  24484. This is the type of the service that runs the @command{dicod} daemon, an
  24485. implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
  24486. @end defvr
  24487. @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
  24488. Return a service that runs the @command{dicod} daemon, an implementation
  24489. of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
  24490. The optional @var{config} argument specifies the configuration for
  24491. @command{dicod}, which should be a @code{<dicod-configuration>} object, by
  24492. default it serves the GNU Collaborative International Dictionary of English.
  24493. You can add @command{open localhost} to your @file{~/.dico} file to make
  24494. @code{localhost} the default server for @command{dico} client
  24495. (@pxref{Initialization File,,, dico, GNU Dico Manual}).
  24496. @end deffn
  24497. @deftp {Data Type} dicod-configuration
  24498. Data type representing the configuration of dicod.
  24499. @table @asis
  24500. @item @code{dico} (default: @var{dico})
  24501. Package object of the GNU Dico dictionary server.
  24502. @item @code{interfaces} (default: @var{'("localhost")})
  24503. This is the list of IP addresses and ports and possibly socket file
  24504. names to listen to (@pxref{Server Settings, @code{listen} directive,,
  24505. dico, GNU Dico Manual}).
  24506. @item @code{handlers} (default: @var{'()})
  24507. List of @code{<dicod-handler>} objects denoting handlers (module instances).
  24508. @item @code{databases} (default: @var{(list %dicod-database:gcide)})
  24509. List of @code{<dicod-database>} objects denoting dictionaries to be served.
  24510. @end table
  24511. @end deftp
  24512. @deftp {Data Type} dicod-handler
  24513. Data type representing a dictionary handler (module instance).
  24514. @table @asis
  24515. @item @code{name}
  24516. Name of the handler (module instance).
  24517. @item @code{module} (default: @var{#f})
  24518. Name of the dicod module of the handler (instance). If it is @code{#f},
  24519. the module has the same name as the handler.
  24520. (@pxref{Modules,,, dico, GNU Dico Manual}).
  24521. @item @code{options}
  24522. List of strings or gexps representing the arguments for the module handler
  24523. @end table
  24524. @end deftp
  24525. @deftp {Data Type} dicod-database
  24526. Data type representing a dictionary database.
  24527. @table @asis
  24528. @item @code{name}
  24529. Name of the database, will be used in DICT commands.
  24530. @item @code{handler}
  24531. Name of the dicod handler (module instance) used by this database
  24532. (@pxref{Handlers,,, dico, GNU Dico Manual}).
  24533. @item @code{complex?} (default: @var{#f})
  24534. Whether the database configuration complex. The complex configuration
  24535. will need a corresponding @code{<dicod-handler>} object, otherwise not.
  24536. @item @code{options}
  24537. List of strings or gexps representing the arguments for the database
  24538. (@pxref{Databases,,, dico, GNU Dico Manual}).
  24539. @end table
  24540. @end deftp
  24541. @defvr {Scheme Variable} %dicod-database:gcide
  24542. A @code{<dicod-database>} object serving the GNU Collaborative International
  24543. Dictionary of English using the @code{gcide} package.
  24544. @end defvr
  24545. The following is an example @code{dicod-service} configuration.
  24546. @lisp
  24547. (dicod-service #:config
  24548. (dicod-configuration
  24549. (handlers (list (dicod-handler
  24550. (name "wordnet")
  24551. (module "dictorg")
  24552. (options
  24553. (list #~(string-append "dbdir=" #$wordnet))))))
  24554. (databases (list (dicod-database
  24555. (name "wordnet")
  24556. (complex? #t)
  24557. (handler "wordnet")
  24558. (options '("database=wn")))
  24559. %dicod-database:gcide))))
  24560. @end lisp
  24561. @cindex Docker
  24562. @subsubheading Docker Service
  24563. The @code{(gnu services docker)} module provides the following services.
  24564. @defvr {Scheme Variable} docker-service-type
  24565. This is the type of the service that runs @url{https://www.docker.com,Docker},
  24566. a daemon that can execute application bundles (sometimes referred to as
  24567. ``containers'') in isolated environments.
  24568. @end defvr
  24569. @deftp {Data Type} docker-configuration
  24570. This is the data type representing the configuration of Docker and Containerd.
  24571. @table @asis
  24572. @item @code{package} (default: @code{docker})
  24573. The Docker daemon package to use.
  24574. @item @code{package} (default: @code{docker-cli})
  24575. The Docker client package to use.
  24576. @item @code{containerd} (default: @var{containerd})
  24577. The Containerd package to use.
  24578. @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
  24579. The Docker user-land networking proxy package to use.
  24580. @item @code{enable-proxy?} (default @code{#t})
  24581. Enable or disable the use of the Docker user-land networking proxy.
  24582. @item @code{debug?} (default @code{#f})
  24583. Enable or disable debug output.
  24584. @item @code{enable-iptables?} (default @code{#t})
  24585. Enable or disable the addition of iptables rules.
  24586. @end table
  24587. @end deftp
  24588. @cindex Singularity, container service
  24589. @defvr {Scheme Variable} singularity-service-type
  24590. This is the type of the service that allows you to run
  24591. @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
  24592. create and run application bundles (aka. ``containers''). The value for this
  24593. service is the Singularity package to use.
  24594. The service does not install a daemon; instead, it installs helper programs as
  24595. setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
  24596. @command{singularity run} and similar commands.
  24597. @end defvr
  24598. @cindex Audit
  24599. @subsubheading Auditd Service
  24600. The @code{(gnu services auditd)} module provides the following service.
  24601. @defvr {Scheme Variable} auditd-service-type
  24602. This is the type of the service that runs
  24603. @url{https://people.redhat.com/sgrubb/audit/,auditd},
  24604. a daemon that tracks security-relevant information on your system.
  24605. Examples of things that can be tracked:
  24606. @enumerate
  24607. @item
  24608. File accesses
  24609. @item
  24610. System calls
  24611. @item
  24612. Invoked commands
  24613. @item
  24614. Failed login attempts
  24615. @item
  24616. Firewall filtering
  24617. @item
  24618. Network access
  24619. @end enumerate
  24620. @command{auditctl} from the @code{audit} package can be used in order
  24621. to add or remove events to be tracked (until the next reboot).
  24622. In order to permanently track events, put the command line arguments
  24623. of auditctl into a file called @code{audit.rules} in the configuration
  24624. directory (see below).
  24625. @command{aureport} from the @code{audit} package can be used in order
  24626. to view a report of all recorded events.
  24627. The audit daemon by default logs into the file
  24628. @file{/var/log/audit.log}.
  24629. @end defvr
  24630. @deftp {Data Type} auditd-configuration
  24631. This is the data type representing the configuration of auditd.
  24632. @table @asis
  24633. @item @code{audit} (default: @code{audit})
  24634. The audit package to use.
  24635. @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
  24636. The directory containing the configuration file for the audit package, which
  24637. must be named @code{auditd.conf}, and optionally some audit rules to
  24638. instantiate on startup.
  24639. @end table
  24640. @end deftp
  24641. @cindex rshiny
  24642. @subsubheading R-Shiny service
  24643. The @code{(gnu services science)} module provides the following service.
  24644. @defvr {Scheme Variable} rshiny-service-type
  24645. This is a type of service which is used to run a webapp created with
  24646. @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
  24647. variable and runs the provided script to call @code{runApp}.
  24648. @deftp {Data Type} rshiny-configuration
  24649. This is the data type representing the configuration of rshiny.
  24650. @table @asis
  24651. @item @code{package} (default: @code{r-shiny})
  24652. The package to use.
  24653. @item @code{binary} (defaunlt @code{"rshiny"})
  24654. The name of the binary or shell script located at @code{package/bin/} to
  24655. run when the service is run.
  24656. The common way to create this file is as follows:
  24657. @lisp
  24658. @dots{}
  24659. (let* ((out (assoc-ref %outputs "out"))
  24660. (targetdir (string-append out "/share/" ,name))
  24661. (app (string-append out "/bin/" ,name))
  24662. (Rbin (string-append (assoc-ref %build-inputs "r-min")
  24663. "/bin/Rscript")))
  24664. ;; @dots{}
  24665. (mkdir-p (string-append out "/bin"))
  24666. (call-with-output-file app
  24667. (lambda (port)
  24668. (format port
  24669. "#!~a
  24670. library(shiny)
  24671. setwd(\"~a\")
  24672. runApp(launch.browser=0, port=4202)~%\n"
  24673. Rbin targetdir))))
  24674. @end lisp
  24675. @end table
  24676. @end deftp
  24677. @end defvr
  24678. @cindex Nix
  24679. @subsubheading Nix service
  24680. The @code{(gnu services nix)} module provides the following service.
  24681. @defvr {Scheme Variable} nix-service-type
  24682. This is the type of the service that runs build daemon of the
  24683. @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
  24684. how to use it:
  24685. @lisp
  24686. (use-modules (gnu))
  24687. (use-service-modules nix)
  24688. (use-package-modules package-management)
  24689. (operating-system
  24690. ;; @dots{}
  24691. (packages (append (list nix)
  24692. %base-packages))
  24693. (services (append (list (service nix-service-type))
  24694. %base-services)))
  24695. @end lisp
  24696. After @command{guix system reconfigure} configure Nix for your user:
  24697. @itemize
  24698. @item Add a Nix channel and update it. See
  24699. @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
  24700. @item Create a symlink to your profile and activate Nix profile:
  24701. @end itemize
  24702. @example
  24703. $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
  24704. $ source /run/current-system/profile/etc/profile.d/nix.sh
  24705. @end example
  24706. @end defvr
  24707. @deftp {Data Type} nix-configuration
  24708. This data type represents the configuration of the Nix daemon.
  24709. @table @asis
  24710. @item @code{nix} (default: @code{nix})
  24711. The Nix package to use.
  24712. @item @code{sandbox} (default: @code{#t})
  24713. Specifies whether builds are sandboxed by default.
  24714. @item @code{build-sandbox-items} (default: @code{'()})
  24715. This is a list of strings or objects appended to the
  24716. @code{build-sandbox-items} field of the configuration file.
  24717. @item @code{extra-config} (default: @code{'()})
  24718. This is a list of strings or objects appended to the configuration file.
  24719. It is used to pass extra text to be added verbatim to the configuration
  24720. file.
  24721. @item @code{extra-options} (default: @code{'()})
  24722. Extra command line options for @code{nix-service-type}.
  24723. @end table
  24724. @end deftp
  24725. @node Setuid Programs
  24726. @section Setuid Programs
  24727. @cindex setuid programs
  24728. Some programs need to run with ``root'' privileges, even when they are
  24729. launched by unprivileged users. A notorious example is the
  24730. @command{passwd} program, which users can run to change their
  24731. password, and which needs to access the @file{/etc/passwd} and
  24732. @file{/etc/shadow} files---something normally restricted to root, for
  24733. obvious security reasons. To address that, these executables are
  24734. @dfn{setuid-root}, meaning that they always run with root privileges
  24735. (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
  24736. for more info about the setuid mechanism).
  24737. The store itself @emph{cannot} contain setuid programs: that would be a
  24738. security issue since any user on the system can write derivations that
  24739. populate the store (@pxref{The Store}). Thus, a different mechanism is
  24740. used: instead of changing the setuid bit directly on files that are in
  24741. the store, we let the system administrator @emph{declare} which programs
  24742. should be setuid root.
  24743. The @code{setuid-programs} field of an @code{operating-system}
  24744. declaration contains a list of G-expressions denoting the names of
  24745. programs to be setuid-root (@pxref{Using the Configuration System}).
  24746. For instance, the @command{passwd} program, which is part of the Shadow
  24747. package, can be designated by this G-expression (@pxref{G-Expressions}):
  24748. @example
  24749. #~(string-append #$shadow "/bin/passwd")
  24750. @end example
  24751. A default set of setuid programs is defined by the
  24752. @code{%setuid-programs} variable of the @code{(gnu system)} module.
  24753. @defvr {Scheme Variable} %setuid-programs
  24754. A list of G-expressions denoting common programs that are setuid-root.
  24755. The list includes commands such as @command{passwd}, @command{ping},
  24756. @command{su}, and @command{sudo}.
  24757. @end defvr
  24758. Under the hood, the actual setuid programs are created in the
  24759. @file{/run/setuid-programs} directory at system activation time. The
  24760. files in this directory refer to the ``real'' binaries, which are in the
  24761. store.
  24762. @node X.509 Certificates
  24763. @section X.509 Certificates
  24764. @cindex HTTPS, certificates
  24765. @cindex X.509 certificates
  24766. @cindex TLS
  24767. Web servers available over HTTPS (that is, HTTP over the transport-layer
  24768. security mechanism, TLS) send client programs an @dfn{X.509 certificate}
  24769. that the client can then use to @emph{authenticate} the server. To do
  24770. that, clients verify that the server's certificate is signed by a
  24771. so-called @dfn{certificate authority} (CA). But to verify the CA's
  24772. signature, clients must have first acquired the CA's certificate.
  24773. Web browsers such as GNU@tie{}IceCat include their own set of CA
  24774. certificates, such that they are able to verify CA signatures
  24775. out-of-the-box.
  24776. However, most other programs that can talk HTTPS---@command{wget},
  24777. @command{git}, @command{w3m}, etc.---need to be told where CA
  24778. certificates can be found.
  24779. @cindex @code{nss-certs}
  24780. In Guix, this is done by adding a package that provides certificates
  24781. to the @code{packages} field of the @code{operating-system} declaration
  24782. (@pxref{operating-system Reference}). Guix includes one such package,
  24783. @code{nss-certs}, which is a set of CA certificates provided as part of
  24784. Mozilla's Network Security Services.
  24785. Note that it is @emph{not} part of @code{%base-packages}, so you need to
  24786. explicitly add it. The @file{/etc/ssl/certs} directory, which is where
  24787. most applications and libraries look for certificates by default, points
  24788. to the certificates installed globally.
  24789. Unprivileged users, including users of Guix on a foreign distro,
  24790. can also install their own certificate package in
  24791. their profile. A number of environment variables need to be defined so
  24792. that applications and libraries know where to find them. Namely, the
  24793. OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
  24794. variables. Some applications add their own environment variables; for
  24795. instance, the Git version control system honors the certificate bundle
  24796. pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
  24797. would typically run something like:
  24798. @example
  24799. guix install nss-certs
  24800. export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
  24801. export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
  24802. export GIT_SSL_CAINFO="$SSL_CERT_FILE"
  24803. @end example
  24804. As another example, R requires the @env{CURL_CA_BUNDLE} environment
  24805. variable to point to a certificate bundle, so you would have to run
  24806. something like this:
  24807. @example
  24808. guix install nss-certs
  24809. export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
  24810. @end example
  24811. For other applications you may want to look up the required environment
  24812. variable in the relevant documentation.
  24813. @node Name Service Switch
  24814. @section Name Service Switch
  24815. @cindex name service switch
  24816. @cindex NSS
  24817. The @code{(gnu system nss)} module provides bindings to the
  24818. configuration file of the libc @dfn{name service switch} or @dfn{NSS}
  24819. (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
  24820. Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
  24821. extended with new ``name'' lookup methods for system databases, which
  24822. includes host names, service names, user accounts, and more (@pxref{Name
  24823. Service Switch, System Databases and Name Service Switch,, libc, The GNU
  24824. C Library Reference Manual}).
  24825. The NSS configuration specifies, for each system database, which lookup
  24826. method is to be used, and how the various methods are chained
  24827. together---for instance, under which circumstances NSS should try the
  24828. next method in the list. The NSS configuration is given in the
  24829. @code{name-service-switch} field of @code{operating-system} declarations
  24830. (@pxref{operating-system Reference, @code{name-service-switch}}).
  24831. @cindex nss-mdns
  24832. @cindex .local, host name lookup
  24833. As an example, the declaration below configures the NSS to use the
  24834. @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
  24835. back-end}, which supports host name lookups over multicast DNS (mDNS)
  24836. for host names ending in @code{.local}:
  24837. @lisp
  24838. (name-service-switch
  24839. (hosts (list %files ;first, check /etc/hosts
  24840. ;; If the above did not succeed, try
  24841. ;; with 'mdns_minimal'.
  24842. (name-service
  24843. (name "mdns_minimal")
  24844. ;; 'mdns_minimal' is authoritative for
  24845. ;; '.local'. When it returns "not found",
  24846. ;; no need to try the next methods.
  24847. (reaction (lookup-specification
  24848. (not-found => return))))
  24849. ;; Then fall back to DNS.
  24850. (name-service
  24851. (name "dns"))
  24852. ;; Finally, try with the "full" 'mdns'.
  24853. (name-service
  24854. (name "mdns")))))
  24855. @end lisp
  24856. Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
  24857. contains this configuration, so you will not have to type it if all you
  24858. want is to have @code{.local} host lookup working.
  24859. Note that, in this case, in addition to setting the
  24860. @code{name-service-switch} of the @code{operating-system} declaration,
  24861. you also need to use @code{avahi-service-type} (@pxref{Networking Services,
  24862. @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
  24863. (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
  24864. to the name service cache daemon (@pxref{Base Services,
  24865. @code{nscd-service}}).
  24866. For convenience, the following variables provide typical NSS
  24867. configurations.
  24868. @defvr {Scheme Variable} %default-nss
  24869. This is the default name service switch configuration, a
  24870. @code{name-service-switch} object.
  24871. @end defvr
  24872. @defvr {Scheme Variable} %mdns-host-lookup-nss
  24873. This is the name service switch configuration with support for host name
  24874. lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
  24875. @end defvr
  24876. The reference for name service switch configuration is given below. It
  24877. is a direct mapping of the configuration file format of the C library , so
  24878. please refer to the C library manual for more information (@pxref{NSS
  24879. Configuration File,,, libc, The GNU C Library Reference Manual}).
  24880. Compared to the configuration file format of libc NSS, it has the advantage
  24881. not only of adding this warm parenthetic feel that we like, but also
  24882. static checks: you will know about syntax errors and typos as soon as you
  24883. run @command{guix system}.
  24884. @deftp {Data Type} name-service-switch
  24885. This is the data type representation the configuration of libc's name
  24886. service switch (NSS). Each field below represents one of the supported
  24887. system databases.
  24888. @table @code
  24889. @item aliases
  24890. @itemx ethers
  24891. @itemx group
  24892. @itemx gshadow
  24893. @itemx hosts
  24894. @itemx initgroups
  24895. @itemx netgroup
  24896. @itemx networks
  24897. @itemx password
  24898. @itemx public-key
  24899. @itemx rpc
  24900. @itemx services
  24901. @itemx shadow
  24902. The system databases handled by the NSS@. Each of these fields must be a
  24903. list of @code{<name-service>} objects (see below).
  24904. @end table
  24905. @end deftp
  24906. @deftp {Data Type} name-service
  24907. This is the data type representing an actual name service and the
  24908. associated lookup action.
  24909. @table @code
  24910. @item name
  24911. A string denoting the name service (@pxref{Services in the NSS
  24912. configuration,,, libc, The GNU C Library Reference Manual}).
  24913. Note that name services listed here must be visible to nscd. This is
  24914. achieved by passing the @code{#:name-services} argument to
  24915. @code{nscd-service} the list of packages providing the needed name
  24916. services (@pxref{Base Services, @code{nscd-service}}).
  24917. @item reaction
  24918. An action specified using the @code{lookup-specification} macro
  24919. (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
  24920. Reference Manual}). For example:
  24921. @lisp
  24922. (lookup-specification (unavailable => continue)
  24923. (success => return))
  24924. @end lisp
  24925. @end table
  24926. @end deftp
  24927. @node Initial RAM Disk
  24928. @section Initial RAM Disk
  24929. @cindex initrd
  24930. @cindex initial RAM disk
  24931. For bootstrapping purposes, the Linux-Libre kernel is passed an
  24932. @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
  24933. root file system as well as an initialization script. The latter is
  24934. responsible for mounting the real root file system, and for loading any
  24935. kernel modules that may be needed to achieve that.
  24936. The @code{initrd-modules} field of an @code{operating-system}
  24937. declaration allows you to specify Linux-libre kernel modules that must
  24938. be available in the initrd. In particular, this is where you would list
  24939. modules needed to actually drive the hard disk where your root partition
  24940. is---although the default value of @code{initrd-modules} should cover
  24941. most use cases. For example, assuming you need the @code{megaraid_sas}
  24942. module in addition to the default modules to be able to access your root
  24943. file system, you would write:
  24944. @lisp
  24945. (operating-system
  24946. ;; @dots{}
  24947. (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
  24948. @end lisp
  24949. @defvr {Scheme Variable} %base-initrd-modules
  24950. This is the list of kernel modules included in the initrd by default.
  24951. @end defvr
  24952. Furthermore, if you need lower-level customization, the @code{initrd}
  24953. field of an @code{operating-system} declaration allows
  24954. you to specify which initrd you would like to use. The @code{(gnu
  24955. system linux-initrd)} module provides three ways to build an initrd: the
  24956. high-level @code{base-initrd} procedure and the low-level
  24957. @code{raw-initrd} and @code{expression->initrd} procedures.
  24958. The @code{base-initrd} procedure is intended to cover most common uses.
  24959. For example, if you want to add a bunch of kernel modules to be loaded
  24960. at boot time, you can define the @code{initrd} field of the operating
  24961. system declaration like this:
  24962. @lisp
  24963. (initrd (lambda (file-systems . rest)
  24964. ;; Create a standard initrd but set up networking
  24965. ;; with the parameters QEMU expects by default.
  24966. (apply base-initrd file-systems
  24967. #:qemu-networking? #t
  24968. rest)))
  24969. @end lisp
  24970. The @code{base-initrd} procedure also handles common use cases that
  24971. involves using the system as a QEMU guest, or as a ``live'' system with
  24972. volatile root file system.
  24973. The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
  24974. Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
  24975. such as trying to guess which kernel modules and packages should be included
  24976. to the initrd. An example use of @code{raw-initrd} is when a user has
  24977. a custom Linux kernel configuration and default kernel modules included by
  24978. @code{base-initrd} are not available.
  24979. The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
  24980. honors several options passed on the Linux kernel command line
  24981. (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
  24982. @code{-append} option of QEMU), notably:
  24983. @table @code
  24984. @item --load=@var{boot}
  24985. Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
  24986. program, once it has mounted the root file system.
  24987. Guix uses this option to yield control to a boot program that runs the
  24988. service activation programs and then spawns the GNU@tie{}Shepherd, the
  24989. initialization system.
  24990. @item --root=@var{root}
  24991. Mount @var{root} as the root file system. @var{root} can be a device
  24992. name like @code{/dev/sda1}, a file system label, or a file system UUID.
  24993. When unspecified, the device name from the root file system of the
  24994. operating system declaration is used.
  24995. @item --system=@var{system}
  24996. Have @file{/run/booted-system} and @file{/run/current-system} point to
  24997. @var{system}.
  24998. @item modprobe.blacklist=@var{modules}@dots{}
  24999. @cindex module, black-listing
  25000. @cindex black list, of kernel modules
  25001. Instruct the initial RAM disk as well as the @command{modprobe} command
  25002. (from the kmod package) to refuse to load @var{modules}. @var{modules}
  25003. must be a comma-separated list of module names---e.g.,
  25004. @code{usbkbd,9pnet}.
  25005. @item --repl
  25006. Start a read-eval-print loop (REPL) from the initial RAM disk before it
  25007. tries to load kernel modules and to mount the root file system. Our
  25008. marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
  25009. love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
  25010. Manual}, for more information on Guile's REPL.
  25011. @end table
  25012. Now that you know all the features that initial RAM disks produced by
  25013. @code{base-initrd} and @code{raw-initrd} provide,
  25014. here is how to use it and customize it further.
  25015. @cindex initrd
  25016. @cindex initial RAM disk
  25017. @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
  25018. [#:linux-modules '()] [#:mapped-devices '()] @
  25019. [#:keyboard-layout #f] @
  25020. [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
  25021. Return a derivation that builds a raw initrd. @var{file-systems} is
  25022. a list of file systems to be mounted by the initrd, possibly in addition to
  25023. the root file system specified on the kernel command line via @option{--root}.
  25024. @var{linux-modules} is a list of kernel modules to be loaded at boot time.
  25025. @var{mapped-devices} is a list of device mappings to realize before
  25026. @var{file-systems} are mounted (@pxref{Mapped Devices}).
  25027. @var{helper-packages} is a list of packages to be copied in the initrd.
  25028. It may
  25029. include @code{e2fsck/static} or other packages needed by the initrd to check
  25030. the root file system.
  25031. When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
  25032. the desired console keyboard layout. This is done before @var{mapped-devices}
  25033. are set up and before @var{file-systems} are mounted such that, should the
  25034. user need to enter a passphrase or use the REPL, this happens using the
  25035. intended keyboard layout.
  25036. When @var{qemu-networking?} is true, set up networking with the standard QEMU
  25037. parameters. When @var{virtio?} is true, load additional modules so that the
  25038. initrd can be used as a QEMU guest with para-virtualized I/O drivers.
  25039. When @var{volatile-root?} is true, the root file system is writable but any changes
  25040. to it are lost.
  25041. @end deffn
  25042. @deffn {Scheme Procedure} base-initrd @var{file-systems} @
  25043. [#:mapped-devices '()] [#:keyboard-layout #f] @
  25044. [#:qemu-networking? #f] [#:volatile-root? #f] @
  25045. [#:linux-modules '()]
  25046. Return as a file-like object a generic initrd, with kernel
  25047. modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
  25048. mounted by the initrd, possibly in addition to the root file system specified
  25049. on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
  25050. mappings to realize before @var{file-systems} are mounted.
  25051. When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
  25052. the desired console keyboard layout. This is done before @var{mapped-devices}
  25053. are set up and before @var{file-systems} are mounted such that, should the
  25054. user need to enter a passphrase or use the REPL, this happens using the
  25055. intended keyboard layout.
  25056. @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
  25057. The initrd is automatically populated with all the kernel modules necessary
  25058. for @var{file-systems} and for the given options. Additional kernel
  25059. modules can be listed in @var{linux-modules}. They will be added to the initrd, and
  25060. loaded at boot time in the order in which they appear.
  25061. @end deffn
  25062. Needless to say, the initrds we produce and use embed a
  25063. statically-linked Guile, and the initialization program is a Guile
  25064. program. That gives a lot of flexibility. The
  25065. @code{expression->initrd} procedure builds such an initrd, given the
  25066. program to run in that initrd.
  25067. @deffn {Scheme Procedure} expression->initrd @var{exp} @
  25068. [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
  25069. Return as a file-like object a Linux initrd (a gzipped cpio archive)
  25070. containing @var{guile} and that evaluates @var{exp}, a G-expression,
  25071. upon booting. All the derivations referenced by @var{exp} are
  25072. automatically copied to the initrd.
  25073. @end deffn
  25074. @node Bootloader Configuration
  25075. @section Bootloader Configuration
  25076. @cindex bootloader
  25077. @cindex boot loader
  25078. The operating system supports multiple bootloaders. The bootloader is
  25079. configured using @code{bootloader-configuration} declaration. All the
  25080. fields of this structure are bootloader agnostic except for one field,
  25081. @code{bootloader} that indicates the bootloader to be configured and
  25082. installed.
  25083. Some of the bootloaders do not honor every field of
  25084. @code{bootloader-configuration}. For instance, the extlinux
  25085. bootloader does not support themes and thus ignores the @code{theme}
  25086. field.
  25087. @deftp {Data Type} bootloader-configuration
  25088. The type of a bootloader configuration declaration.
  25089. @table @asis
  25090. @item @code{bootloader}
  25091. @cindex EFI, bootloader
  25092. @cindex UEFI, bootloader
  25093. @cindex BIOS, bootloader
  25094. The bootloader to use, as a @code{bootloader} object. For now
  25095. @code{grub-bootloader}, @code{grub-efi-bootloader},
  25096. @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
  25097. @code{u-boot-bootloader} are supported.
  25098. @cindex ARM, bootloaders
  25099. @cindex AArch64, bootloaders
  25100. Available bootloaders are described in @code{(gnu bootloader @dots{})}
  25101. modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
  25102. of bootloaders for a wide range of ARM and AArch64 systems, using the
  25103. @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
  25104. @vindex grub-efi-bootloader
  25105. @code{grub-efi-bootloader} allows to boot on modern systems using the
  25106. @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
  25107. use if the installation image contains a @file{/sys/firmware/efi} directory
  25108. when you boot it on your system.
  25109. @vindex grub-bootloader
  25110. @code{grub-bootloader} allows you to boot in particular Intel-based machines
  25111. in ``legacy'' BIOS mode.
  25112. @vindex grub-efi-netboot-bootloader
  25113. @code{grub-efi-netboot-bootloader} allows you to boot your system over network
  25114. through TFTP@. In combination with an NFS root file system this allows you to
  25115. build a diskless Guix system.
  25116. The installation of the @code{grub-efi-netboot-bootloader} generates the content
  25117. of the TFTP root directory at @code{target}
  25118. (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
  25119. You may want to mount your TFTP server directory onto @code{target} to move the
  25120. required files to the TFTP server automatically.
  25121. If you plan to use an NFS root file system as well (actually if you mount the
  25122. store from an NFS share), then the TFTP server needs to serve the file
  25123. @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
  25124. image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
  25125. initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
  25126. files from the store will be accessed by GRUB through TFTP with their normal
  25127. store path, for example as
  25128. @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
  25129. Two symlinks are created to make this possible. The first symlink is
  25130. @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
  25131. @file{../../../boot/grub/grub.cfg},
  25132. where @code{target} may be @file{/boot}. In this case the link is not leaving
  25133. the served TFTP root directory, but otherwise it does. The second link is
  25134. @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
  25135. is leaving the served TFTP root directory.
  25136. The assumption behind all this is that you have an NFS server exporting the root
  25137. file system for your Guix system, and additionally a TFTP server exporting your
  25138. @code{target} directory—usually @file{/boot}—from that same root file system for
  25139. your Guix system. In this constellation the symlinks will work.
  25140. For other constellations you will have to program your own bootloader installer,
  25141. which then takes care to make necessary files from the store accessible through
  25142. TFTP, for example by copying them into the TFTP root directory at @code{target}.
  25143. It is important to note that symlinks pointing outside the TFTP root directory
  25144. may need to be allowed in the configuration of your TFTP server. Further the
  25145. store link exposes the whole store through TFTP@. Both points need to be
  25146. considered carefully for security aspects.
  25147. Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
  25148. NFS servers, you also need a properly configured DHCP server to make the booting
  25149. over netboot possible. For all this we can currently only recommend you to look
  25150. for instructions about @acronym{PXE, Preboot eXecution Environment}.
  25151. @item @code{target}
  25152. This is a string denoting the target onto which to install the
  25153. bootloader.
  25154. The interpretation depends on the bootloader in question. For
  25155. @code{grub-bootloader}, for example, it should be a device name understood by
  25156. the bootloader @command{installer} command, such as @code{/dev/sda} or
  25157. @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
  25158. @code{grub-efi-bootloader}, it should be the mount point of the EFI file
  25159. system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
  25160. @code{target} should be the mount point corresponding to the TFTP root
  25161. directory of your TFTP server.
  25162. @item @code{menu-entries} (default: @code{()})
  25163. A possibly empty list of @code{menu-entry} objects (see below), denoting
  25164. entries to appear in the bootloader menu, in addition to the current
  25165. system entry and the entry pointing to previous system generations.
  25166. @item @code{default-entry} (default: @code{0})
  25167. The index of the default boot menu entry. Index 0 is for the entry of the
  25168. current system.
  25169. @item @code{timeout} (default: @code{5})
  25170. The number of seconds to wait for keyboard input before booting. Set to
  25171. 0 to boot immediately, and to -1 to wait indefinitely.
  25172. @cindex keyboard layout, for the bootloader
  25173. @item @code{keyboard-layout} (default: @code{#f})
  25174. If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
  25175. layout, usually US@tie{}English (``qwerty'').
  25176. Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
  25177. Layout}).
  25178. @quotation Note
  25179. This option is currently ignored by bootloaders other than @code{grub} and
  25180. @code{grub-efi}.
  25181. @end quotation
  25182. @item @code{theme} (default: @var{#f})
  25183. The bootloader theme object describing the theme to use. If no theme
  25184. is provided, some bootloaders might use a default theme, that's true
  25185. for GRUB.
  25186. @item @code{terminal-outputs} (default: @code{'(gfxterm)})
  25187. The output terminals used for the bootloader boot menu, as a list of
  25188. symbols. GRUB accepts the values: @code{console}, @code{serial},
  25189. @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
  25190. @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
  25191. corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
  25192. configuration,,, grub,GNU GRUB manual}).
  25193. @item @code{terminal-inputs} (default: @code{'()})
  25194. The input terminals used for the bootloader boot menu, as a list of
  25195. symbols. For GRUB, the default is the native platform terminal as
  25196. determined at run-time. GRUB accepts the values: @code{console},
  25197. @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
  25198. @code{usb_keyboard}. This field corresponds to the GRUB variable
  25199. @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
  25200. manual}).
  25201. @item @code{serial-unit} (default: @code{#f})
  25202. The serial unit used by the bootloader, as an integer from 0 to 3.
  25203. For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
  25204. corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
  25205. @item @code{serial-speed} (default: @code{#f})
  25206. The speed of the serial interface, as an integer. For GRUB, the
  25207. default value is chosen at run-time; currently GRUB chooses
  25208. 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
  25209. @end table
  25210. @end deftp
  25211. @cindex dual boot
  25212. @cindex boot menu
  25213. Should you want to list additional boot menu entries @i{via} the
  25214. @code{menu-entries} field above, you will need to create them with the
  25215. @code{menu-entry} form. For example, imagine you want to be able to
  25216. boot another distro (hard to imagine!), you can define a menu entry
  25217. along these lines:
  25218. @lisp
  25219. (menu-entry
  25220. (label "The Other Distro")
  25221. (linux "/boot/old/vmlinux-2.6.32")
  25222. (linux-arguments '("root=/dev/sda2"))
  25223. (initrd "/boot/old/initrd"))
  25224. @end lisp
  25225. Details below.
  25226. @deftp {Data Type} menu-entry
  25227. The type of an entry in the bootloader menu.
  25228. @table @asis
  25229. @item @code{label}
  25230. The label to show in the menu---e.g., @code{"GNU"}.
  25231. @item @code{linux} (default: @code{#f})
  25232. The Linux kernel image to boot, for example:
  25233. @lisp
  25234. (file-append linux-libre "/bzImage")
  25235. @end lisp
  25236. For GRUB, it is also possible to specify a device explicitly in the
  25237. file path using GRUB's device naming convention (@pxref{Naming
  25238. convention,,, grub, GNU GRUB manual}), for example:
  25239. @example
  25240. "(hd0,msdos1)/boot/vmlinuz"
  25241. @end example
  25242. If the device is specified explicitly as above, then the @code{device}
  25243. field is ignored entirely.
  25244. @item @code{linux-arguments} (default: @code{()})
  25245. The list of extra Linux kernel command-line arguments---e.g.,
  25246. @code{("console=ttyS0")}.
  25247. @item @code{initrd} (default: @code{#f})
  25248. A G-Expression or string denoting the file name of the initial RAM disk
  25249. to use (@pxref{G-Expressions}).
  25250. @item @code{device} (default: @code{#f})
  25251. The device where the kernel and initrd are to be found---i.e., for GRUB,
  25252. @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
  25253. This may be a file system label (a string), a file system UUID (a
  25254. bytevector, @pxref{File Systems}), or @code{#f}, in which case
  25255. the bootloader will search the device containing the file specified by
  25256. the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
  25257. must @emph{not} be an OS device name such as @file{/dev/sda1}.
  25258. @item @code{multiboot-kernel} (default: @code{#f})
  25259. The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
  25260. manual}). When this field is set, a Multiboot menu-entry is generated.
  25261. For example:
  25262. @lisp
  25263. (file-append mach "/boot/gnumach")
  25264. @end lisp
  25265. @item @code{multiboot-arguments} (default: @code{()})
  25266. The list of extra command-line arguments for the multiboot-kernel.
  25267. @item @code{multiboot-modules} (default: @code{()})
  25268. The list of commands for loading Multiboot modules. For example:
  25269. @lisp
  25270. (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
  25271. @dots{})
  25272. (list (file-append libc "/lib/ld.so.1") "exec"
  25273. @dots{}))
  25274. @end lisp
  25275. @end table
  25276. @end deftp
  25277. @cindex HDPI
  25278. @cindex HiDPI
  25279. @cindex resolution
  25280. @c FIXME: Write documentation once it's stable.
  25281. For now only GRUB has theme support. GRUB themes are created using
  25282. the @code{grub-theme} form, which is not fully documented yet.
  25283. @deftp {Data Type} grub-theme
  25284. Data type representing the configuration of the GRUB theme.
  25285. @table @asis
  25286. @item @code{gfxmode} (default: @code{'("auto")})
  25287. The GRUB @code{gfxmode} to set (a list of screen resolution strings,
  25288. @pxref{gfxmode,,, grub, GNU GRUB manual}).
  25289. @end table
  25290. @end deftp
  25291. @deffn {Scheme Procedure} grub-theme
  25292. Return the default GRUB theme used by the operating system if no
  25293. @code{theme} field is specified in @code{bootloader-configuration}
  25294. record.
  25295. It comes with a fancy background image displaying the GNU and Guix
  25296. logos.
  25297. @end deffn
  25298. For example, to override the default resolution, you may use something
  25299. like
  25300. @lisp
  25301. (bootloader
  25302. (bootloader-configuration
  25303. ;; @dots{}
  25304. (theme (grub-theme
  25305. (inherit (grub-theme))
  25306. (gfxmode '("1024x786x32" "auto"))))))
  25307. @end lisp
  25308. @node Invoking guix system
  25309. @section Invoking @code{guix system}
  25310. Once you have written an operating system declaration as seen in the
  25311. previous section, it can be @dfn{instantiated} using the @command{guix
  25312. system} command. The synopsis is:
  25313. @example
  25314. guix system @var{options}@dots{} @var{action} @var{file}
  25315. @end example
  25316. @var{file} must be the name of a file containing an
  25317. @code{operating-system} declaration. @var{action} specifies how the
  25318. operating system is instantiated. Currently the following values are
  25319. supported:
  25320. @table @code
  25321. @item search
  25322. Display available service type definitions that match the given regular
  25323. expressions, sorted by relevance:
  25324. @cindex HDPI
  25325. @cindex HiDPI
  25326. @cindex resolution
  25327. @example
  25328. $ guix system search console
  25329. name: console-fonts
  25330. location: gnu/services/base.scm:806:2
  25331. extends: shepherd-root
  25332. description: Install the given fonts on the specified ttys (fonts are per
  25333. + virtual console on GNU/Linux). The value of this service is a list of
  25334. + tty/font pairs. The font can be the name of a font provided by the `kbd'
  25335. + package or any valid argument to `setfont', as in this example:
  25336. +
  25337. + '(("tty1" . "LatGrkCyr-8x16")
  25338. + ("tty2" . (file-append
  25339. + font-tamzen
  25340. + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
  25341. + ("tty3" . (file-append
  25342. + font-terminus
  25343. + "/share/consolefonts/ter-132n"))) ; for HDPI
  25344. relevance: 9
  25345. name: mingetty
  25346. location: gnu/services/base.scm:1190:2
  25347. extends: shepherd-root
  25348. description: Provide console login using the `mingetty' program.
  25349. relevance: 2
  25350. name: login
  25351. location: gnu/services/base.scm:860:2
  25352. extends: pam
  25353. description: Provide a console log-in service as specified by its
  25354. + configuration value, a `login-configuration' object.
  25355. relevance: 2
  25356. @dots{}
  25357. @end example
  25358. As for @command{guix package --search}, the result is written in
  25359. @code{recutils} format, which makes it easy to filter the output
  25360. (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
  25361. @item reconfigure
  25362. Build the operating system described in @var{file}, activate it, and
  25363. switch to it@footnote{This action (and the related actions
  25364. @code{switch-generation} and @code{roll-back}) are usable only on
  25365. systems already running Guix System.}.
  25366. @quotation Note
  25367. @c The paragraph below refers to the problem discussed at
  25368. @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
  25369. It is highly recommended to run @command{guix pull} once before you run
  25370. @command{guix system reconfigure} for the first time (@pxref{Invoking
  25371. guix pull}). Failing to do that you would see an older version of Guix
  25372. once @command{reconfigure} has completed.
  25373. @end quotation
  25374. This effects all the configuration specified in @var{file}: user
  25375. accounts, system services, global package list, setuid programs, etc.
  25376. The command starts system services specified in @var{file} that are not
  25377. currently running; if a service is currently running this command will
  25378. arrange for it to be upgraded the next time it is stopped (e.g.@: by
  25379. @code{herd stop X} or @code{herd restart X}).
  25380. This command creates a new generation whose number is one greater than
  25381. the current generation (as reported by @command{guix system
  25382. list-generations}). If that generation already exists, it will be
  25383. overwritten. This behavior mirrors that of @command{guix package}
  25384. (@pxref{Invoking guix package}).
  25385. It also adds a bootloader menu entry for the new OS configuration,
  25386. ---unless @option{--no-bootloader} is passed. For GRUB, it moves
  25387. entries for older configurations to a submenu, allowing you to choose
  25388. an older system generation at boot time should you need it.
  25389. @cindex provenance tracking, of the operating system
  25390. Upon completion, the new system is deployed under
  25391. @file{/run/current-system}. This directory contains @dfn{provenance
  25392. meta-data}: the list of channels in use (@pxref{Channels}) and
  25393. @var{file} itself, when available. You can view it by running:
  25394. @example
  25395. guix system describe
  25396. @end example
  25397. This information is useful should you later want to inspect how this
  25398. particular generation was built. In fact, assuming @var{file} is
  25399. self-contained, you can later rebuild generation @var{n} of your
  25400. operating system with:
  25401. @example
  25402. guix time-machine \
  25403. -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
  25404. system reconfigure \
  25405. /var/guix/profiles/system-@var{n}-link/configuration.scm
  25406. @end example
  25407. You can think of it as some sort of built-in version control! Your
  25408. system is not just a binary artifact: @emph{it carries its own source}.
  25409. @xref{Service Reference, @code{provenance-service-type}}, for more
  25410. information on provenance tracking.
  25411. By default, @command{reconfigure} @emph{prevents you from downgrading
  25412. your system}, which could (re)introduce security vulnerabilities and
  25413. also cause problems with ``stateful'' services such as database
  25414. management systems. You can override that behavior by passing
  25415. @option{--allow-downgrades}.
  25416. @item switch-generation
  25417. @cindex generations
  25418. Switch to an existing system generation. This action atomically
  25419. switches the system profile to the specified system generation. It
  25420. also rearranges the system's existing bootloader menu entries. It
  25421. makes the menu entry for the specified system generation the default,
  25422. and it moves the entries for the other generations to a submenu, if
  25423. supported by the bootloader being used. The next time the system
  25424. boots, it will use the specified system generation.
  25425. The bootloader itself is not being reinstalled when using this
  25426. command. Thus, the installed bootloader is used with an updated
  25427. configuration file.
  25428. The target generation can be specified explicitly by its generation
  25429. number. For example, the following invocation would switch to system
  25430. generation 7:
  25431. @example
  25432. guix system switch-generation 7
  25433. @end example
  25434. The target generation can also be specified relative to the current
  25435. generation with the form @code{+N} or @code{-N}, where @code{+3} means
  25436. ``3 generations ahead of the current generation,'' and @code{-1} means
  25437. ``1 generation prior to the current generation.'' When specifying a
  25438. negative value such as @code{-1}, you must precede it with @code{--} to
  25439. prevent it from being parsed as an option. For example:
  25440. @example
  25441. guix system switch-generation -- -1
  25442. @end example
  25443. Currently, the effect of invoking this action is @emph{only} to switch
  25444. the system profile to an existing generation and rearrange the
  25445. bootloader menu entries. To actually start using the target system
  25446. generation, you must reboot after running this action. In the future,
  25447. it will be updated to do the same things as @command{reconfigure},
  25448. like activating and deactivating services.
  25449. This action will fail if the specified generation does not exist.
  25450. @item roll-back
  25451. @cindex rolling back
  25452. Switch to the preceding system generation. The next time the system
  25453. boots, it will use the preceding system generation. This is the inverse
  25454. of @command{reconfigure}, and it is exactly the same as invoking
  25455. @command{switch-generation} with an argument of @code{-1}.
  25456. Currently, as with @command{switch-generation}, you must reboot after
  25457. running this action to actually start using the preceding system
  25458. generation.
  25459. @item delete-generations
  25460. @cindex deleting system generations
  25461. @cindex saving space
  25462. Delete system generations, making them candidates for garbage collection
  25463. (@pxref{Invoking guix gc}, for information on how to run the ``garbage
  25464. collector'').
  25465. This works in the same way as @samp{guix package --delete-generations}
  25466. (@pxref{Invoking guix package, @option{--delete-generations}}). With no
  25467. arguments, all system generations but the current one are deleted:
  25468. @example
  25469. guix system delete-generations
  25470. @end example
  25471. You can also select the generations you want to delete. The example below
  25472. deletes all the system generations that are more than two month old:
  25473. @example
  25474. guix system delete-generations 2m
  25475. @end example
  25476. Running this command automatically reinstalls the bootloader with an updated
  25477. list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
  25478. longer lists the generations that have been deleted.
  25479. @item build
  25480. Build the derivation of the operating system, which includes all the
  25481. configuration files and programs needed to boot and run the system.
  25482. This action does not actually install anything.
  25483. @item init
  25484. Populate the given directory with all the files necessary to run the
  25485. operating system specified in @var{file}. This is useful for first-time
  25486. installations of Guix System. For instance:
  25487. @example
  25488. guix system init my-os-config.scm /mnt
  25489. @end example
  25490. copies to @file{/mnt} all the store items required by the configuration
  25491. specified in @file{my-os-config.scm}. This includes configuration
  25492. files, packages, and so on. It also creates other essential files
  25493. needed for the system to operate correctly---e.g., the @file{/etc},
  25494. @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
  25495. This command also installs bootloader on the target specified in
  25496. @file{my-os-config}, unless the @option{--no-bootloader} option was
  25497. passed.
  25498. @item vm
  25499. @cindex virtual machine
  25500. @cindex VM
  25501. @anchor{guix system vm}
  25502. Build a virtual machine that contains the operating system declared in
  25503. @var{file}, and return a script to run that virtual machine (VM).
  25504. @quotation Note
  25505. The @code{vm} action and others below
  25506. can use KVM support in the Linux-libre kernel. Specifically, if the
  25507. machine has hardware virtualization support, the corresponding
  25508. KVM kernel module should be loaded, and the @file{/dev/kvm} device node
  25509. must exist and be readable and writable by the user and by the
  25510. build users of the daemon (@pxref{Build Environment Setup}).
  25511. @end quotation
  25512. Arguments given to the script are passed to QEMU as in the example
  25513. below, which enables networking and requests 1@tie{}GiB of RAM for the
  25514. emulated machine:
  25515. @example
  25516. $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
  25517. @end example
  25518. The VM shares its store with the host system.
  25519. Additional file systems can be shared between the host and the VM using
  25520. the @option{--share} and @option{--expose} command-line options: the former
  25521. specifies a directory to be shared with write access, while the latter
  25522. provides read-only access to the shared directory.
  25523. The example below creates a VM in which the user's home directory is
  25524. accessible read-only, and where the @file{/exchange} directory is a
  25525. read-write mapping of @file{$HOME/tmp} on the host:
  25526. @example
  25527. guix system vm my-config.scm \
  25528. --expose=$HOME --share=$HOME/tmp=/exchange
  25529. @end example
  25530. On GNU/Linux, the default is to boot directly to the kernel; this has
  25531. the advantage of requiring only a very tiny root disk image since the
  25532. store of the host can then be mounted.
  25533. The @option{--full-boot} option forces a complete boot sequence, starting
  25534. with the bootloader. This requires more disk space since a root image
  25535. containing at least the kernel, initrd, and bootloader data files must
  25536. be created. The @option{--image-size} option can be used to specify the
  25537. size of the image.
  25538. @cindex System images, creation in various formats
  25539. @cindex Creating system images in various formats
  25540. @item image
  25541. @itemx docker-image
  25542. Return a virtual machine, disk image, or Docker image of the operating
  25543. system declared in @var{file} that stands alone. By default,
  25544. @command{guix system} estimates the size of the image needed to store
  25545. the system, but you can use the @option{--image-size} option to specify
  25546. a value. Docker images are built to contain exactly what they need, so
  25547. the @option{--image-size} option is ignored in the case of
  25548. @code{docker-image}.
  25549. @cindex image, creating disk images
  25550. The @code{image} command can produce various image types. The
  25551. image type can be selected using the @option{--image-type} option. It
  25552. defaults to @code{efi-raw}. When its value is @code{iso9660}, the
  25553. @option{--label} option can be used to specify a volume ID with
  25554. @code{image}. By default, the root file system of a disk image is
  25555. mounted non-volatile; the @option{--volatile} option can be provided to
  25556. make it volatile instead. When using @code{image}, the bootloader
  25557. installed on the generated image is taken from the provided
  25558. @code{operating-system} definition. The following example demonstrates
  25559. how to generate an image that uses the @code{grub-efi-bootloader}
  25560. bootloader and boot it with QEMU:
  25561. @example
  25562. image=$(guix system image --image-type=qcow2 \
  25563. gnu/system/examples/lightweight-desktop.tmpl)
  25564. cp $image /tmp/my-image.qcow2
  25565. chmod +w /tmp/my-image.qcow2
  25566. qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
  25567. -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
  25568. @end example
  25569. When using the @code{efi-raw} image type, a raw disk image is produced;
  25570. it can be copied as is to a USB stick, for instance. Assuming
  25571. @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
  25572. the image to it using the following command:
  25573. @example
  25574. # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
  25575. @end example
  25576. The @code{--list-image-types} command lists all the available image
  25577. types.
  25578. @cindex creating virtual machine images
  25579. When using the @code{qcow2} image type, the returned image is in qcow2
  25580. format, which the QEMU emulator can efficiently use. @xref{Running Guix
  25581. in a VM}, for more information on how to run the image in a virtual
  25582. machine. The @code{grub-bootloader} bootloader is always used
  25583. independently of what is declared in the @code{operating-system} file
  25584. passed as argument. This is to make it easier to work with QEMU, which
  25585. uses the SeaBIOS BIOS by default, expecting a bootloader to be installed
  25586. in the Master Boot Record (MBR).
  25587. @cindex docker-image, creating docker images
  25588. When using @code{docker-image}, a Docker image is produced. Guix builds
  25589. the image from scratch, not from a pre-existing Docker base image. As a
  25590. result, it contains @emph{exactly} what you define in the operating
  25591. system configuration file. You can then load the image and launch a
  25592. Docker container using commands like the following:
  25593. @example
  25594. image_id="`docker load < guix-system-docker-image.tar.gz`"
  25595. container_id="`docker create $image_id`"
  25596. docker start $container_id
  25597. @end example
  25598. This command starts a new Docker container from the specified image. It
  25599. will boot the Guix system in the usual manner, which means it will
  25600. start any services you have defined in the operating system
  25601. configuration. You can get an interactive shell running in the container
  25602. using @command{docker exec}:
  25603. @example
  25604. docker exec -ti $container_id /run/current-system/profile/bin/bash --login
  25605. @end example
  25606. Depending on what you run in the Docker container, it
  25607. may be necessary to give the container additional permissions. For
  25608. example, if you intend to build software using Guix inside of the Docker
  25609. container, you may need to pass the @option{--privileged} option to
  25610. @code{docker create}.
  25611. Last, the @option{--network} option applies to @command{guix system
  25612. docker-image}: it produces an image where network is supposedly shared
  25613. with the host, and thus without services like nscd or NetworkManager.
  25614. @item container
  25615. Return a script to run the operating system declared in @var{file}
  25616. within a container. Containers are a set of lightweight isolation
  25617. mechanisms provided by the kernel Linux-libre. Containers are
  25618. substantially less resource-demanding than full virtual machines since
  25619. the kernel, shared objects, and other resources can be shared with the
  25620. host system; this also means they provide thinner isolation.
  25621. Currently, the script must be run as root in order to support more than
  25622. a single user and group. The container shares its store with the host
  25623. system.
  25624. As with the @code{vm} action (@pxref{guix system vm}), additional file
  25625. systems to be shared between the host and container can be specified
  25626. using the @option{--share} and @option{--expose} options:
  25627. @example
  25628. guix system container my-config.scm \
  25629. --expose=$HOME --share=$HOME/tmp=/exchange
  25630. @end example
  25631. @quotation Note
  25632. This option requires Linux-libre 3.19 or newer.
  25633. @end quotation
  25634. @end table
  25635. @var{options} can contain any of the common build options (@pxref{Common
  25636. Build Options}). In addition, @var{options} can contain one of the
  25637. following:
  25638. @table @option
  25639. @item --expression=@var{expr}
  25640. @itemx -e @var{expr}
  25641. Consider the operating-system @var{expr} evaluates to.
  25642. This is an alternative to specifying a file which evaluates to an
  25643. operating system.
  25644. This is used to generate the Guix system installer @pxref{Building the
  25645. Installation Image}).
  25646. @item --system=@var{system}
  25647. @itemx -s @var{system}
  25648. Attempt to build for @var{system} instead of the host system type.
  25649. This works as per @command{guix build} (@pxref{Invoking guix build}).
  25650. @item --derivation
  25651. @itemx -d
  25652. Return the derivation file name of the given operating system without
  25653. building anything.
  25654. @cindex provenance tracking, of the operating system
  25655. @item --save-provenance
  25656. As discussed above, @command{guix system init} and @command{guix system
  25657. reconfigure} always save provenance information @i{via} a dedicated
  25658. service (@pxref{Service Reference, @code{provenance-service-type}}).
  25659. However, other commands don't do that by default. If you wish to, say,
  25660. create a virtual machine image that contains provenance information, you
  25661. can run:
  25662. @example
  25663. guix system image -t qcow2 --save-provenance config.scm
  25664. @end example
  25665. That way, the resulting image will effectively ``embed its own source''
  25666. in the form of meta-data in @file{/run/current-system}. With that
  25667. information, one can rebuild the image to make sure it really contains
  25668. what it pretends to contain; or they could use that to derive a variant
  25669. of the image.
  25670. @item --image-type=@var{type}
  25671. @itemx -t @var{type}
  25672. For the @code{image} action, create an image with given @var{type}.
  25673. When this option is omitted, @command{guix system} uses the
  25674. @code{efi-raw} image type.
  25675. @cindex ISO-9660 format
  25676. @cindex CD image format
  25677. @cindex DVD image format
  25678. @option{--image-type=iso9660} produces an ISO-9660 image, suitable
  25679. for burning on CDs and DVDs.
  25680. @item --image-size=@var{size}
  25681. For the @code{image} action, create an image of the given @var{size}.
  25682. @var{size} may be a number of bytes, or it may include a unit as a
  25683. suffix (@pxref{Block size, size specifications,, coreutils, GNU
  25684. Coreutils}).
  25685. When this option is omitted, @command{guix system} computes an estimate
  25686. of the image size as a function of the size of the system declared in
  25687. @var{file}.
  25688. @item --network
  25689. @itemx -N
  25690. For the @code{container} action, allow containers to access the host network,
  25691. that is, do not create a network namespace.
  25692. @item --root=@var{file}
  25693. @itemx -r @var{file}
  25694. Make @var{file} a symlink to the result, and register it as a garbage
  25695. collector root.
  25696. @item --skip-checks
  25697. Skip pre-installation safety checks.
  25698. By default, @command{guix system init} and @command{guix system
  25699. reconfigure} perform safety checks: they make sure the file systems that
  25700. appear in the @code{operating-system} declaration actually exist
  25701. (@pxref{File Systems}), and that any Linux kernel modules that may be
  25702. needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
  25703. RAM Disk}). Passing this option skips these tests altogether.
  25704. @item --allow-downgrades
  25705. Instruct @command{guix system reconfigure} to allow system downgrades.
  25706. By default, @command{reconfigure} prevents you from downgrading your
  25707. system. It achieves that by comparing the provenance info of your
  25708. system (shown by @command{guix system describe}) with that of your
  25709. @command{guix} command (shown by @command{guix describe}). If the
  25710. commits for @command{guix} are not descendants of those used for your
  25711. system, @command{guix system reconfigure} errors out. Passing
  25712. @option{--allow-downgrades} allows you to bypass these checks.
  25713. @quotation Note
  25714. Make sure you understand its security implications before using
  25715. @option{--allow-downgrades}.
  25716. @end quotation
  25717. @cindex on-error
  25718. @cindex on-error strategy
  25719. @cindex error strategy
  25720. @item --on-error=@var{strategy}
  25721. Apply @var{strategy} when an error occurs when reading @var{file}.
  25722. @var{strategy} may be one of the following:
  25723. @table @code
  25724. @item nothing-special
  25725. Report the error concisely and exit. This is the default strategy.
  25726. @item backtrace
  25727. Likewise, but also display a backtrace.
  25728. @item debug
  25729. Report the error and enter Guile's debugger. From there, you can run
  25730. commands such as @code{,bt} to get a backtrace, @code{,locals} to
  25731. display local variable values, and more generally inspect the state of the
  25732. program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
  25733. a list of available debugging commands.
  25734. @end table
  25735. @end table
  25736. Once you have built, configured, re-configured, and re-re-configured
  25737. your Guix installation, you may find it useful to list the operating
  25738. system generations available on disk---and that you can choose from the
  25739. bootloader boot menu:
  25740. @table @code
  25741. @item describe
  25742. Describe the current system generation: its file name, the kernel and
  25743. bootloader used, etc., as well as provenance information when available.
  25744. @item list-generations
  25745. List a summary of each generation of the operating system available on
  25746. disk, in a human-readable way. This is similar to the
  25747. @option{--list-generations} option of @command{guix package}
  25748. (@pxref{Invoking guix package}).
  25749. Optionally, one can specify a pattern, with the same syntax that is used
  25750. in @command{guix package --list-generations}, to restrict the list of
  25751. generations displayed. For instance, the following command displays
  25752. generations that are up to 10 days old:
  25753. @example
  25754. $ guix system list-generations 10d
  25755. @end example
  25756. @end table
  25757. The @command{guix system} command has even more to offer! The following
  25758. sub-commands allow you to visualize how your system services relate to
  25759. each other:
  25760. @anchor{system-extension-graph}
  25761. @table @code
  25762. @item extension-graph
  25763. Emit to standard output the @dfn{service
  25764. extension graph} of the operating system defined in @var{file}
  25765. (@pxref{Service Composition}, for more information on service
  25766. extensions). By default the output is in Dot/Graphviz format, but you
  25767. can choose a different format with @option{--graph-backend}, as with
  25768. @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
  25769. The command:
  25770. @example
  25771. $ guix system extension-graph @var{file} | xdot -
  25772. @end example
  25773. shows the extension relations among services.
  25774. @anchor{system-shepherd-graph}
  25775. @item shepherd-graph
  25776. Emit to standard output the @dfn{dependency
  25777. graph} of shepherd services of the operating system defined in
  25778. @var{file}. @xref{Shepherd Services}, for more information and for an
  25779. example graph.
  25780. Again, the default output format is Dot/Graphviz, but you can pass
  25781. @option{--graph-backend} to select a different one.
  25782. @end table
  25783. @node Invoking guix deploy
  25784. @section Invoking @code{guix deploy}
  25785. We've already seen @code{operating-system} declarations used to manage a
  25786. machine's configuration locally. Suppose you need to configure multiple
  25787. machines, though---perhaps you're managing a service on the web that's
  25788. comprised of several servers. @command{guix deploy} enables you to use those
  25789. same @code{operating-system} declarations to manage multiple remote hosts at
  25790. once as a logical ``deployment''.
  25791. @quotation Note
  25792. The functionality described in this section is still under development
  25793. and is subject to change. Get in touch with us on
  25794. @email{guix-devel@@gnu.org}!
  25795. @end quotation
  25796. @example
  25797. guix deploy @var{file}
  25798. @end example
  25799. Such an invocation will deploy the machines that the code within @var{file}
  25800. evaluates to. As an example, @var{file} might contain a definition like this:
  25801. @lisp
  25802. ;; This is a Guix deployment of a "bare bones" setup, with
  25803. ;; no X11 display server, to a machine with an SSH daemon
  25804. ;; listening on localhost:2222. A configuration such as this
  25805. ;; may be appropriate for virtual machine with ports
  25806. ;; forwarded to the host's loopback interface.
  25807. (use-service-modules networking ssh)
  25808. (use-package-modules bootloaders)
  25809. (define %system
  25810. (operating-system
  25811. (host-name "gnu-deployed")
  25812. (timezone "Etc/UTC")
  25813. (bootloader (bootloader-configuration
  25814. (bootloader grub-bootloader)
  25815. (target "/dev/vda")
  25816. (terminal-outputs '(console))))
  25817. (file-systems (cons (file-system
  25818. (mount-point "/")
  25819. (device "/dev/vda1")
  25820. (type "ext4"))
  25821. %base-file-systems))
  25822. (services
  25823. (append (list (service dhcp-client-service-type)
  25824. (service openssh-service-type
  25825. (openssh-configuration
  25826. (permit-root-login #t)
  25827. (allow-empty-passwords? #t))))
  25828. %base-services))))
  25829. (list (machine
  25830. (operating-system %system)
  25831. (environment managed-host-environment-type)
  25832. (configuration (machine-ssh-configuration
  25833. (host-name "localhost")
  25834. (system "x86_64-linux")
  25835. (user "alice")
  25836. (identity "./id_rsa")
  25837. (port 2222)))))
  25838. @end lisp
  25839. The file should evaluate to a list of @var{machine} objects. This example,
  25840. upon being deployed, will create a new generation on the remote system
  25841. realizing the @code{operating-system} declaration @code{%system}.
  25842. @code{environment} and @code{configuration} specify how the machine should be
  25843. provisioned---that is, how the computing resources should be created and
  25844. managed. The above example does not create any resources, as a
  25845. @code{'managed-host} is a machine that is already running the Guix system and
  25846. available over the network. This is a particularly simple case; a more
  25847. complex deployment may involve, for example, starting virtual machines through
  25848. a Virtual Private Server (VPS) provider. In such a case, a different
  25849. @var{environment} type would be used.
  25850. Do note that you first need to generate a key pair on the coordinator machine
  25851. to allow the daemon to export signed archives of files from the store
  25852. (@pxref{Invoking guix archive}), though this step is automatic on Guix
  25853. System:
  25854. @example
  25855. # guix archive --generate-key
  25856. @end example
  25857. @noindent
  25858. Each target machine must authorize the key of the master machine so that it
  25859. accepts store items it receives from the coordinator:
  25860. @example
  25861. # guix archive --authorize < coordinator-public-key.txt
  25862. @end example
  25863. @code{user}, in this example, specifies the name of the user account to log in
  25864. as to perform the deployment. Its default value is @code{root}, but root
  25865. login over SSH may be forbidden in some cases. To work around this,
  25866. @command{guix deploy} can log in as an unprivileged user and employ
  25867. @code{sudo} to escalate privileges. This will only work if @code{sudo} is
  25868. currently installed on the remote and can be invoked non-interactively as
  25869. @code{user}. That is, the line in @code{sudoers} granting @code{user} the
  25870. ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
  25871. be accomplished with the following operating system configuration snippet:
  25872. @lisp
  25873. (use-modules ...
  25874. (gnu system)) ;for %sudoers-specification
  25875. (define %user "username")
  25876. (operating-system
  25877. ...
  25878. (sudoers-file
  25879. (plain-file "sudoers"
  25880. (string-append (plain-file-content %sudoers-specification)
  25881. (format #f "~a ALL = NOPASSWD: ALL~%"
  25882. %user)))))
  25883. @end lisp
  25884. For more information regarding the format of the @file{sudoers} file,
  25885. consult @command{man sudoers}.
  25886. @deftp {Data Type} machine
  25887. This is the data type representing a single machine in a heterogeneous Guix
  25888. deployment.
  25889. @table @asis
  25890. @item @code{operating-system}
  25891. The object of the operating system configuration to deploy.
  25892. @item @code{environment}
  25893. An @code{environment-type} describing how the machine should be provisioned.
  25894. @item @code{configuration} (default: @code{#f})
  25895. An object describing the configuration for the machine's @code{environment}.
  25896. If the @code{environment} has a default configuration, @code{#f} may be used.
  25897. If @code{#f} is used for an environment with no default configuration,
  25898. however, an error will be thrown.
  25899. @end table
  25900. @end deftp
  25901. @deftp {Data Type} machine-ssh-configuration
  25902. This is the data type representing the SSH client parameters for a machine
  25903. with an @code{environment} of @code{managed-host-environment-type}.
  25904. @table @asis
  25905. @item @code{host-name}
  25906. @item @code{build-locally?} (default: @code{#t})
  25907. If false, system derivations will be built on the machine being deployed to.
  25908. @item @code{system}
  25909. The system type describing the architecture of the machine being deployed
  25910. to---e.g., @code{"x86_64-linux"}.
  25911. @item @code{authorize?} (default: @code{#t})
  25912. If true, the coordinator's signing key will be added to the remote's ACL
  25913. keyring.
  25914. @item @code{port} (default: @code{22})
  25915. @item @code{user} (default: @code{"root"})
  25916. @item @code{identity} (default: @code{#f})
  25917. If specified, the path to the SSH private key to use to authenticate with the
  25918. remote host.
  25919. @item @code{host-key} (default: @code{#f})
  25920. This should be the SSH host key of the machine, which looks like this:
  25921. @example
  25922. ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
  25923. @end example
  25924. When @code{host-key} is @code{#f}, the server is authenticated against
  25925. the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
  25926. client does.
  25927. @item @code{allow-downgrades?} (default: @code{#f})
  25928. Whether to allow potential downgrades.
  25929. Like @command{guix system reconfigure}, @command{guix deploy} compares
  25930. the channel commits currently deployed on the remote host (as returned
  25931. by @command{guix system describe}) to those currently in use (as
  25932. returned by @command{guix describe}) to determine whether commits
  25933. currently in use are descendants of those deployed. When this is not
  25934. the case and @code{allow-downgrades?} is false, it raises an error.
  25935. This ensures you do not accidentally downgrade remote machines.
  25936. @end table
  25937. @end deftp
  25938. @deftp {Data Type} digital-ocean-configuration
  25939. This is the data type describing the Droplet that should be created for a
  25940. machine with an @code{environment} of @code{digital-ocean-environment-type}.
  25941. @table @asis
  25942. @item @code{ssh-key}
  25943. The path to the SSH private key to use to authenticate with the remote
  25944. host. In the future, this field may not exist.
  25945. @item @code{tags}
  25946. A list of string ``tags'' that uniquely identify the machine. Must be given
  25947. such that no two machines in the deployment have the same set of tags.
  25948. @item @code{region}
  25949. A Digital Ocean region slug, such as @code{"nyc3"}.
  25950. @item @code{size}
  25951. A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
  25952. @item @code{enable-ipv6?}
  25953. Whether or not the droplet should be created with IPv6 networking.
  25954. @end table
  25955. @end deftp
  25956. @node Running Guix in a VM
  25957. @section Running Guix in a Virtual Machine
  25958. @cindex virtual machine
  25959. To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
  25960. distributed at
  25961. @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
  25962. This image is a compressed image in QCOW format. You will first need to
  25963. decompress with @command{xz -d}, and then you can pass it to an emulator such
  25964. as QEMU (see below for details).
  25965. This image boots the Xfce graphical environment and it contains some
  25966. commonly used tools. You can install more software in the image by running
  25967. @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
  25968. also reconfigure the system based on its initial configuration file available
  25969. as @file{/run/current-system/configuration.scm} (@pxref{Using the
  25970. Configuration System}).
  25971. Instead of using this pre-built image, one can also build their own virtual
  25972. machine image using @command{guix system vm-image} (@pxref{Invoking guix
  25973. system}). The returned image is in qcow2 format, which the
  25974. @uref{https://qemu.org/, QEMU emulator} can efficiently use.
  25975. @cindex QEMU
  25976. If you built your own image, you must copy it out of the store
  25977. (@pxref{The Store}) and give yourself permission to write to the copy
  25978. before you can use it. When invoking QEMU, you must choose a system
  25979. emulator that is suitable for your hardware platform. Here is a minimal
  25980. QEMU invocation that will boot the result of @command{guix system
  25981. image -t qcow2} on x86_64 hardware:
  25982. @example
  25983. $ qemu-system-x86_64 \
  25984. -nic user,model=virtio-net-pci \
  25985. -enable-kvm -m 1024 \
  25986. -device virtio-blk,drive=myhd \
  25987. -drive if=none,file=/tmp/qemu-image,id=myhd
  25988. @end example
  25989. Here is what each of these options means:
  25990. @table @code
  25991. @item qemu-system-x86_64
  25992. This specifies the hardware platform to emulate. This should match the
  25993. host.
  25994. @item -nic user,model=virtio-net-pci
  25995. Enable the unprivileged user-mode network stack. The guest OS can
  25996. access the host but not vice versa. This is the simplest way to get the
  25997. guest OS online. @code{model} specifies which network device to emulate:
  25998. @code{virtio-net-pci} is a special device made for virtualized operating
  25999. systems and recommended for most uses. Assuming your hardware platform is
  26000. x86_64, you can get a list of available NIC models by running
  26001. @command{qemu-system-x86_64 -nic model=help}.
  26002. @item -enable-kvm
  26003. If your system has hardware virtualization extensions, enabling the
  26004. virtual machine support (KVM) of the Linux kernel will make things run
  26005. faster.
  26006. @c To run Xfce + 'guix pull', we need at least 1G of RAM.
  26007. @item -m 1024
  26008. RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
  26009. which may be insufficient for some operations.
  26010. @item -device virtio-blk,drive=myhd
  26011. Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
  26012. ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
  26013. better performance than if it were emulating a complete disk drive. See the
  26014. QEMU and KVM documentation for more info.
  26015. @item -drive if=none,file=/tmp/qemu-image,id=myhd
  26016. Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
  26017. store of the ``myhd'' drive.
  26018. @end table
  26019. The default @command{run-vm.sh} script that is returned by an invocation of
  26020. @command{guix system vm} does not add a @command{-nic user} flag by default.
  26021. To get network access from within the vm add the @code{(dhcp-client-service)}
  26022. to your system definition and start the VM using
  26023. @command{`guix system vm config.scm` -nic user}. An important caveat of using
  26024. @command{-nic user} for networking is that @command{ping} will not work, because
  26025. it uses the ICMP protocol. You'll have to use a different command to check for
  26026. network connectivity, for example @command{guix download}.
  26027. @subsection Connecting Through SSH
  26028. @cindex SSH
  26029. @cindex SSH server
  26030. To enable SSH inside a VM you need to add an SSH server like
  26031. @code{openssh-service-type} to your VM (@pxref{Networking Services,
  26032. @code{openssh-service-type}}). In addition you need to forward the SSH port,
  26033. 22 by default, to the host. You can do this with
  26034. @example
  26035. `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
  26036. @end example
  26037. To connect to the VM you can run
  26038. @example
  26039. ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
  26040. @end example
  26041. The @command{-p} tells @command{ssh} the port you want to connect to.
  26042. @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
  26043. every time you modify your @command{config.scm} file and the
  26044. @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
  26045. connection to an unknown host every time you connect.
  26046. @subsection Using @command{virt-viewer} with Spice
  26047. As an alternative to the default @command{qemu} graphical client you can
  26048. use the @command{remote-viewer} from the @command{virt-viewer} package. To
  26049. connect pass the @command{-spice port=5930,disable-ticketing} flag to
  26050. @command{qemu}. See previous section for further information on how to do this.
  26051. Spice also allows you to do some nice stuff like share your clipboard with your
  26052. VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
  26053. @example
  26054. -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
  26055. -chardev spicevmc,name=vdagent,id=vdagent
  26056. -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
  26057. name=com.redhat.spice.0
  26058. @end example
  26059. You'll also need to add the @code{(spice-vdagent-service)} to your
  26060. system definition (@pxref{Miscellaneous Services, Spice service}).
  26061. @node Defining Services
  26062. @section Defining Services
  26063. The previous sections show the available services and how one can combine
  26064. them in an @code{operating-system} declaration. But how do we define
  26065. them in the first place? And what is a service anyway?
  26066. @menu
  26067. * Service Composition:: The model for composing services.
  26068. * Service Types and Services:: Types and services.
  26069. * Service Reference:: API reference.
  26070. * Shepherd Services:: A particular type of service.
  26071. @end menu
  26072. @node Service Composition
  26073. @subsection Service Composition
  26074. @cindex services
  26075. @cindex daemons
  26076. Here we define a @dfn{service} as, broadly, something that extends the
  26077. functionality of the operating system. Often a service is a process---a
  26078. @dfn{daemon}---started when the system boots: a secure shell server, a
  26079. Web server, the Guix build daemon, etc. Sometimes a service is a daemon
  26080. whose execution can be triggered by another daemon---e.g., an FTP server
  26081. started by @command{inetd} or a D-Bus service activated by
  26082. @command{dbus-daemon}. Occasionally, a service does not map to a
  26083. daemon. For instance, the ``account'' service collects user accounts
  26084. and makes sure they exist when the system runs; the ``udev'' service
  26085. collects device management rules and makes them available to the eudev
  26086. daemon; the @file{/etc} service populates the @file{/etc} directory
  26087. of the system.
  26088. @cindex service extensions
  26089. Guix system services are connected by @dfn{extensions}. For instance, the
  26090. secure shell service @emph{extends} the Shepherd---the
  26091. initialization system, running as PID@tie{}1---by giving it the command
  26092. lines to start and stop the secure shell daemon (@pxref{Networking
  26093. Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
  26094. service by passing it its @file{.service} specification, and extends the
  26095. udev service by passing it device management rules (@pxref{Desktop
  26096. Services, @code{upower-service}}); the Guix daemon service extends the
  26097. Shepherd by passing it the command lines to start and stop the daemon,
  26098. and extends the account service by passing it a list of required build
  26099. user accounts (@pxref{Base Services}).
  26100. All in all, services and their ``extends'' relations form a directed
  26101. acyclic graph (DAG). If we represent services as boxes and extensions
  26102. as arrows, a typical system might provide something like this:
  26103. @image{images/service-graph,,5in,Typical service extension graph.}
  26104. @cindex system service
  26105. At the bottom, we see the @dfn{system service}, which produces the
  26106. directory containing everything to run and boot the system, as returned
  26107. by the @command{guix system build} command. @xref{Service Reference},
  26108. to learn about the other service types shown here.
  26109. @xref{system-extension-graph, the @command{guix system extension-graph}
  26110. command}, for information on how to generate this representation for a
  26111. particular operating system definition.
  26112. @cindex service types
  26113. Technically, developers can define @dfn{service types} to express these
  26114. relations. There can be any number of services of a given type on the
  26115. system---for instance, a system running two instances of the GNU secure
  26116. shell server (lsh) has two instances of @code{lsh-service-type}, with
  26117. different parameters.
  26118. The following section describes the programming interface for service
  26119. types and services.
  26120. @node Service Types and Services
  26121. @subsection Service Types and Services
  26122. A @dfn{service type} is a node in the DAG described above. Let us start
  26123. with a simple example, the service type for the Guix build daemon
  26124. (@pxref{Invoking guix-daemon}):
  26125. @lisp
  26126. (define guix-service-type
  26127. (service-type
  26128. (name 'guix)
  26129. (extensions
  26130. (list (service-extension shepherd-root-service-type guix-shepherd-service)
  26131. (service-extension account-service-type guix-accounts)
  26132. (service-extension activation-service-type guix-activation)))
  26133. (default-value (guix-configuration))))
  26134. @end lisp
  26135. @noindent
  26136. It defines three things:
  26137. @enumerate
  26138. @item
  26139. A name, whose sole purpose is to make inspection and debugging easier.
  26140. @item
  26141. A list of @dfn{service extensions}, where each extension designates the
  26142. target service type and a procedure that, given the parameters of the
  26143. service, returns a list of objects to extend the service of that type.
  26144. Every service type has at least one service extension. The only
  26145. exception is the @dfn{boot service type}, which is the ultimate service.
  26146. @item
  26147. Optionally, a default value for instances of this type.
  26148. @end enumerate
  26149. In this example, @code{guix-service-type} extends three services:
  26150. @table @code
  26151. @item shepherd-root-service-type
  26152. The @code{guix-shepherd-service} procedure defines how the Shepherd
  26153. service is extended. Namely, it returns a @code{<shepherd-service>}
  26154. object that defines how @command{guix-daemon} is started and stopped
  26155. (@pxref{Shepherd Services}).
  26156. @item account-service-type
  26157. This extension for this service is computed by @code{guix-accounts},
  26158. which returns a list of @code{user-group} and @code{user-account}
  26159. objects representing the build user accounts (@pxref{Invoking
  26160. guix-daemon}).
  26161. @item activation-service-type
  26162. Here @code{guix-activation} is a procedure that returns a gexp, which is
  26163. a code snippet to run at ``activation time''---e.g., when the service is
  26164. booted.
  26165. @end table
  26166. A service of this type is instantiated like this:
  26167. @lisp
  26168. (service guix-service-type
  26169. (guix-configuration
  26170. (build-accounts 5)
  26171. (extra-options '("--gc-keep-derivations"))))
  26172. @end lisp
  26173. The second argument to the @code{service} form is a value representing
  26174. the parameters of this specific service instance.
  26175. @xref{guix-configuration-type, @code{guix-configuration}}, for
  26176. information about the @code{guix-configuration} data type. When the
  26177. value is omitted, the default value specified by
  26178. @code{guix-service-type} is used:
  26179. @lisp
  26180. (service guix-service-type)
  26181. @end lisp
  26182. @code{guix-service-type} is quite simple because it extends other
  26183. services but is not extensible itself.
  26184. @c @subsubsubsection Extensible Service Types
  26185. The service type for an @emph{extensible} service looks like this:
  26186. @lisp
  26187. (define udev-service-type
  26188. (service-type (name 'udev)
  26189. (extensions
  26190. (list (service-extension shepherd-root-service-type
  26191. udev-shepherd-service)))
  26192. (compose concatenate) ;concatenate the list of rules
  26193. (extend (lambda (config rules)
  26194. (match config
  26195. (($ <udev-configuration> udev initial-rules)
  26196. (udev-configuration
  26197. (udev udev) ;the udev package to use
  26198. (rules (append initial-rules rules)))))))))
  26199. @end lisp
  26200. This is the service type for the
  26201. @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
  26202. management daemon}. Compared to the previous example, in addition to an
  26203. extension of @code{shepherd-root-service-type}, we see two new fields:
  26204. @table @code
  26205. @item compose
  26206. This is the procedure to @dfn{compose} the list of extensions to
  26207. services of this type.
  26208. Services can extend the udev service by passing it lists of rules; we
  26209. compose those extensions simply by concatenating them.
  26210. @item extend
  26211. This procedure defines how the value of the service is @dfn{extended} with
  26212. the composition of the extensions.
  26213. Udev extensions are composed into a list of rules, but the udev service
  26214. value is itself a @code{<udev-configuration>} record. So here, we
  26215. extend that record by appending the list of rules it contains to the
  26216. list of contributed rules.
  26217. @item description
  26218. This is a string giving an overview of the service type. The string can
  26219. contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
  26220. @command{guix system search} command searches these strings and displays
  26221. them (@pxref{Invoking guix system}).
  26222. @end table
  26223. There can be only one instance of an extensible service type such as
  26224. @code{udev-service-type}. If there were more, the
  26225. @code{service-extension} specifications would be ambiguous.
  26226. Still here? The next section provides a reference of the programming
  26227. interface for services.
  26228. @node Service Reference
  26229. @subsection Service Reference
  26230. We have seen an overview of service types (@pxref{Service Types and
  26231. Services}). This section provides a reference on how to manipulate
  26232. services and service types. This interface is provided by the
  26233. @code{(gnu services)} module.
  26234. @deffn {Scheme Procedure} service @var{type} [@var{value}]
  26235. Return a new service of @var{type}, a @code{<service-type>} object (see
  26236. below). @var{value} can be any object; it represents the parameters of
  26237. this particular service instance.
  26238. When @var{value} is omitted, the default value specified by @var{type}
  26239. is used; if @var{type} does not specify a default value, an error is
  26240. raised.
  26241. For instance, this:
  26242. @lisp
  26243. (service openssh-service-type)
  26244. @end lisp
  26245. @noindent
  26246. is equivalent to this:
  26247. @lisp
  26248. (service openssh-service-type
  26249. (openssh-configuration))
  26250. @end lisp
  26251. In both cases the result is an instance of @code{openssh-service-type}
  26252. with the default configuration.
  26253. @end deffn
  26254. @deffn {Scheme Procedure} service? @var{obj}
  26255. Return true if @var{obj} is a service.
  26256. @end deffn
  26257. @deffn {Scheme Procedure} service-kind @var{service}
  26258. Return the type of @var{service}---i.e., a @code{<service-type>} object.
  26259. @end deffn
  26260. @deffn {Scheme Procedure} service-value @var{service}
  26261. Return the value associated with @var{service}. It represents its
  26262. parameters.
  26263. @end deffn
  26264. Here is an example of how a service is created and manipulated:
  26265. @lisp
  26266. (define s
  26267. (service nginx-service-type
  26268. (nginx-configuration
  26269. (nginx nginx)
  26270. (log-directory log-directory)
  26271. (run-directory run-directory)
  26272. (file config-file))))
  26273. (service? s)
  26274. @result{} #t
  26275. (eq? (service-kind s) nginx-service-type)
  26276. @result{} #t
  26277. @end lisp
  26278. The @code{modify-services} form provides a handy way to change the
  26279. parameters of some of the services of a list such as
  26280. @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
  26281. evaluates to a list of services. Of course, you could always use
  26282. standard list combinators such as @code{map} and @code{fold} to do that
  26283. (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
  26284. @code{modify-services} simply provides a more concise form for this
  26285. common pattern.
  26286. @deffn {Scheme Syntax} modify-services @var{services} @
  26287. (@var{type} @var{variable} => @var{body}) @dots{}
  26288. Modify the services listed in @var{services} according to the given
  26289. clauses. Each clause has the form:
  26290. @example
  26291. (@var{type} @var{variable} => @var{body})
  26292. @end example
  26293. where @var{type} is a service type---e.g.,
  26294. @code{guix-service-type}---and @var{variable} is an identifier that is
  26295. bound within the @var{body} to the service parameters---e.g., a
  26296. @code{guix-configuration} instance---of the original service of that
  26297. @var{type}.
  26298. The @var{body} should evaluate to the new service parameters, which will
  26299. be used to configure the new service. This new service will replace the
  26300. original in the resulting list. Because a service's service parameters
  26301. are created using @code{define-record-type*}, you can write a succinct
  26302. @var{body} that evaluates to the new service parameters by using the
  26303. @code{inherit} feature that @code{define-record-type*} provides.
  26304. @xref{Using the Configuration System}, for example usage.
  26305. @end deffn
  26306. Next comes the programming interface for service types. This is
  26307. something you want to know when writing new service definitions, but not
  26308. necessarily when simply looking for ways to customize your
  26309. @code{operating-system} declaration.
  26310. @deftp {Data Type} service-type
  26311. @cindex service type
  26312. This is the representation of a @dfn{service type} (@pxref{Service Types
  26313. and Services}).
  26314. @table @asis
  26315. @item @code{name}
  26316. This is a symbol, used only to simplify inspection and debugging.
  26317. @item @code{extensions}
  26318. A non-empty list of @code{<service-extension>} objects (see below).
  26319. @item @code{compose} (default: @code{#f})
  26320. If this is @code{#f}, then the service type denotes services that cannot
  26321. be extended---i.e., services that do not receive ``values'' from other
  26322. services.
  26323. Otherwise, it must be a one-argument procedure. The procedure is called
  26324. by @code{fold-services} and is passed a list of values collected from
  26325. extensions. It may return any single value.
  26326. @item @code{extend} (default: @code{#f})
  26327. If this is @code{#f}, services of this type cannot be extended.
  26328. Otherwise, it must be a two-argument procedure: @code{fold-services}
  26329. calls it, passing it the initial value of the service as the first
  26330. argument and the result of applying @code{compose} to the extension
  26331. values as the second argument. It must return a value that is a valid
  26332. parameter value for the service instance.
  26333. @item @code{description}
  26334. This is a string, possibly using Texinfo markup, describing in a couple
  26335. of sentences what the service is about. This string allows users to
  26336. find about the service through @command{guix system search}
  26337. (@pxref{Invoking guix system}).
  26338. @item @code{default-value} (default: @code{&no-default-value})
  26339. The default value associated for instances of this service type. This
  26340. allows users to use the @code{service} form without its second argument:
  26341. @lisp
  26342. (service @var{type})
  26343. @end lisp
  26344. The returned service in this case has the default value specified by
  26345. @var{type}.
  26346. @end table
  26347. @xref{Service Types and Services}, for examples.
  26348. @end deftp
  26349. @deffn {Scheme Procedure} service-extension @var{target-type} @
  26350. @var{compute}
  26351. Return a new extension for services of type @var{target-type}.
  26352. @var{compute} must be a one-argument procedure: @code{fold-services}
  26353. calls it, passing it the value associated with the service that provides
  26354. the extension; it must return a valid value for the target service.
  26355. @end deffn
  26356. @deffn {Scheme Procedure} service-extension? @var{obj}
  26357. Return true if @var{obj} is a service extension.
  26358. @end deffn
  26359. Occasionally, you might want to simply extend an existing service. This
  26360. involves creating a new service type and specifying the extension of
  26361. interest, which can be verbose; the @code{simple-service} procedure
  26362. provides a shorthand for this.
  26363. @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
  26364. Return a service that extends @var{target} with @var{value}. This works
  26365. by creating a singleton service type @var{name}, of which the returned
  26366. service is an instance.
  26367. For example, this extends mcron (@pxref{Scheduled Job Execution}) with
  26368. an additional job:
  26369. @lisp
  26370. (simple-service 'my-mcron-job mcron-service-type
  26371. #~(job '(next-hour (3)) "guix gc -F 2G"))
  26372. @end lisp
  26373. @end deffn
  26374. At the core of the service abstraction lies the @code{fold-services}
  26375. procedure, which is responsible for ``compiling'' a list of services
  26376. down to a single directory that contains everything needed to boot and
  26377. run the system---the directory shown by the @command{guix system build}
  26378. command (@pxref{Invoking guix system}). In essence, it propagates
  26379. service extensions down the service graph, updating each node parameters
  26380. on the way, until it reaches the root node.
  26381. @deffn {Scheme Procedure} fold-services @var{services} @
  26382. [#:target-type @var{system-service-type}]
  26383. Fold @var{services} by propagating their extensions down to the root of
  26384. type @var{target-type}; return the root service adjusted accordingly.
  26385. @end deffn
  26386. Lastly, the @code{(gnu services)} module also defines several essential
  26387. service types, some of which are listed below.
  26388. @defvr {Scheme Variable} system-service-type
  26389. This is the root of the service graph. It produces the system directory
  26390. as returned by the @command{guix system build} command.
  26391. @end defvr
  26392. @defvr {Scheme Variable} boot-service-type
  26393. The type of the ``boot service'', which produces the @dfn{boot script}.
  26394. The boot script is what the initial RAM disk runs when booting.
  26395. @end defvr
  26396. @defvr {Scheme Variable} etc-service-type
  26397. The type of the @file{/etc} service. This service is used to create
  26398. files under @file{/etc} and can be extended by
  26399. passing it name/file tuples such as:
  26400. @lisp
  26401. (list `("issue" ,(plain-file "issue" "Welcome!\n")))
  26402. @end lisp
  26403. In this example, the effect would be to add an @file{/etc/issue} file
  26404. pointing to the given file.
  26405. @end defvr
  26406. @defvr {Scheme Variable} setuid-program-service-type
  26407. Type for the ``setuid-program service''. This service collects lists of
  26408. executable file names, passed as gexps, and adds them to the set of
  26409. setuid-root programs on the system (@pxref{Setuid Programs}).
  26410. @end defvr
  26411. @defvr {Scheme Variable} profile-service-type
  26412. Type of the service that populates the @dfn{system profile}---i.e., the
  26413. programs under @file{/run/current-system/profile}. Other services can
  26414. extend it by passing it lists of packages to add to the system profile.
  26415. @end defvr
  26416. @cindex provenance tracking, of the operating system
  26417. @anchor{provenance-service-type}
  26418. @defvr {Scheme Variable} provenance-service-type
  26419. This is the type of the service that records @dfn{provenance meta-data}
  26420. in the system itself. It creates several files under
  26421. @file{/run/current-system}:
  26422. @table @file
  26423. @item channels.scm
  26424. This is a ``channel file'' that can be passed to @command{guix pull -C}
  26425. or @command{guix time-machine -C}, and which describes the channels used
  26426. to build the system, if that information was available
  26427. (@pxref{Channels}).
  26428. @item configuration.scm
  26429. This is the file that was passed as the value for this
  26430. @code{provenance-service-type} service. By default, @command{guix
  26431. system reconfigure} automatically passes the OS configuration file it
  26432. received on the command line.
  26433. @item provenance
  26434. This contains the same information as the two other files but in a
  26435. format that is more readily processable.
  26436. @end table
  26437. In general, these two pieces of information (channels and configuration
  26438. file) are enough to reproduce the operating system ``from source''.
  26439. @quotation Caveats
  26440. This information is necessary to rebuild your operating system, but it
  26441. is not always sufficient. In particular, @file{configuration.scm}
  26442. itself is insufficient if it is not self-contained---if it refers to
  26443. external Guile modules or to extra files. If you want
  26444. @file{configuration.scm} to be self-contained, we recommend that modules
  26445. or files it refers to be part of a channel.
  26446. Besides, provenance meta-data is ``silent'' in the sense that it does
  26447. not change the bits contained in your system, @emph{except for the
  26448. meta-data bits themselves}. Two different OS configurations or sets of
  26449. channels can lead to the same system, bit-for-bit; when
  26450. @code{provenance-service-type} is used, these two systems will have
  26451. different meta-data and thus different store file names, which makes
  26452. comparison less trivial.
  26453. @end quotation
  26454. This service is automatically added to your operating system
  26455. configuration when you use @command{guix system reconfigure},
  26456. @command{guix system init}, or @command{guix deploy}.
  26457. @end defvr
  26458. @node Shepherd Services
  26459. @subsection Shepherd Services
  26460. @cindex shepherd services
  26461. @cindex PID 1
  26462. @cindex init system
  26463. The @code{(gnu services shepherd)} module provides a way to define
  26464. services managed by the GNU@tie{}Shepherd, which is the
  26465. initialization system---the first process that is started when the
  26466. system boots, also known as PID@tie{}1
  26467. (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
  26468. Services in the Shepherd can depend on each other. For instance, the
  26469. SSH daemon may need to be started after the syslog daemon has been
  26470. started, which in turn can only happen once all the file systems have
  26471. been mounted. The simple operating system defined earlier (@pxref{Using
  26472. the Configuration System}) results in a service graph like this:
  26473. @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
  26474. You can actually generate such a graph for any operating system
  26475. definition using the @command{guix system shepherd-graph} command
  26476. (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
  26477. The @code{%shepherd-root-service} is a service object representing
  26478. PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
  26479. by passing it lists of @code{<shepherd-service>} objects.
  26480. @deftp {Data Type} shepherd-service
  26481. The data type representing a service managed by the Shepherd.
  26482. @table @asis
  26483. @item @code{provision}
  26484. This is a list of symbols denoting what the service provides.
  26485. These are the names that may be passed to @command{herd start},
  26486. @command{herd status}, and similar commands (@pxref{Invoking herd,,,
  26487. shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
  26488. @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
  26489. @item @code{requirement} (default: @code{'()})
  26490. List of symbols denoting the Shepherd services this one depends on.
  26491. @cindex one-shot services, for the Shepherd
  26492. @item @code{one-shot?} (default: @code{#f})
  26493. Whether this service is @dfn{one-shot}. One-shot services stop immediately
  26494. after their @code{start} action has completed. @xref{Slots of services,,,
  26495. shepherd, The GNU Shepherd Manual}, for more info.
  26496. @item @code{respawn?} (default: @code{#t})
  26497. Whether to restart the service when it stops, for instance when the
  26498. underlying process dies.
  26499. @item @code{start}
  26500. @itemx @code{stop} (default: @code{#~(const #f)})
  26501. The @code{start} and @code{stop} fields refer to the Shepherd's
  26502. facilities to start and stop processes (@pxref{Service De- and
  26503. Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
  26504. G-expressions that get expanded in the Shepherd configuration file
  26505. (@pxref{G-Expressions}).
  26506. @item @code{actions} (default: @code{'()})
  26507. @cindex actions, of Shepherd services
  26508. This is a list of @code{shepherd-action} objects (see below) defining
  26509. @dfn{actions} supported by the service, in addition to the standard
  26510. @code{start} and @code{stop} actions. Actions listed here become available as
  26511. @command{herd} sub-commands:
  26512. @example
  26513. herd @var{action} @var{service} [@var{arguments}@dots{}]
  26514. @end example
  26515. @item @code{auto-start?} (default: @code{#t})
  26516. Whether this service should be started automatically by the Shepherd. If it
  26517. is @code{#f} the service has to be started manually with @code{herd start}.
  26518. @item @code{documentation}
  26519. A documentation string, as shown when running:
  26520. @example
  26521. herd doc @var{service-name}
  26522. @end example
  26523. where @var{service-name} is one of the symbols in @code{provision}
  26524. (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
  26525. @item @code{modules} (default: @code{%default-modules})
  26526. This is the list of modules that must be in scope when @code{start} and
  26527. @code{stop} are evaluated.
  26528. @end table
  26529. @end deftp
  26530. The example below defines a Shepherd service that spawns
  26531. @command{syslogd}, the system logger from the GNU Networking Utilities
  26532. (@pxref{syslogd invocation, @command{syslogd},, inetutils, GNU
  26533. Inetutils}):
  26534. @example
  26535. (let ((config (plain-file "syslogd.conf" "@dots{}")))
  26536. (shepherd-service
  26537. (documentation "Run the syslog daemon (syslogd).")
  26538. (provision '(syslogd))
  26539. (requirement '(user-processes))
  26540. (start #~(make-forkexec-constructor
  26541. (list #$(file-append inetutils "/libexec/syslogd")
  26542. "--rcfile" #$config)
  26543. #:pid-file "/var/run/syslog.pid"))
  26544. (stop #~(make-kill-destructor))))
  26545. @end example
  26546. Key elements in this example are the @code{start} and @code{stop}
  26547. fields: they are @dfn{staged} code snippets that use the
  26548. @code{make-forkexec-constructor} procedure provided by the Shepherd and
  26549. its dual, @code{make-kill-destructor} (@pxref{Service De- and
  26550. Constructors,,, shepherd, The GNU Shepherd Manual}). The @code{start}
  26551. field will have @command{shepherd} spawn @command{syslogd} with the
  26552. given option; note that we pass @code{config} after @option{--rcfile},
  26553. which is a configuration file declared above (contents of this file are
  26554. omitted). Likewise, the @code{stop} field tells how this service is to
  26555. be stopped; in this case, it is stopped by making the @code{kill} system
  26556. call on its PID@. Code staging is achieved using G-expressions:
  26557. @code{#~} stages code, while @code{#$} ``escapes'' back to host code
  26558. (@pxref{G-Expressions}).
  26559. @deftp {Data Type} shepherd-action
  26560. This is the data type that defines additional actions implemented by a
  26561. Shepherd service (see above).
  26562. @table @code
  26563. @item name
  26564. Symbol naming the action.
  26565. @item documentation
  26566. This is a documentation string for the action. It can be viewed by running:
  26567. @example
  26568. herd doc @var{service} action @var{action}
  26569. @end example
  26570. @item procedure
  26571. This should be a gexp that evaluates to a procedure of at least one argument,
  26572. which is the ``running value'' of the service (@pxref{Slots of services,,,
  26573. shepherd, The GNU Shepherd Manual}).
  26574. @end table
  26575. The following example defines an action called @code{say-hello} that kindly
  26576. greets the user:
  26577. @lisp
  26578. (shepherd-action
  26579. (name 'say-hello)
  26580. (documentation "Say hi!")
  26581. (procedure #~(lambda (running . args)
  26582. (format #t "Hello, friend! arguments: ~s\n"
  26583. args)
  26584. #t)))
  26585. @end lisp
  26586. Assuming this action is added to the @code{example} service, then you can do:
  26587. @example
  26588. # herd say-hello example
  26589. Hello, friend! arguments: ()
  26590. # herd say-hello example a b c
  26591. Hello, friend! arguments: ("a" "b" "c")
  26592. @end example
  26593. This, as you can see, is a fairly sophisticated way to say hello.
  26594. @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
  26595. info on actions.
  26596. @end deftp
  26597. @defvr {Scheme Variable} shepherd-root-service-type
  26598. The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
  26599. This is the service type that extensions target when they want to create
  26600. shepherd services (@pxref{Service Types and Services}, for an example).
  26601. Each extension must pass a list of @code{<shepherd-service>}. Its
  26602. value must be a @code{shepherd-configuration}, as described below.
  26603. @end defvr
  26604. @deftp {Data Type} shepherd-configuration
  26605. This data type represents the Shepherd's configuration.
  26606. @table @code
  26607. @item shepherd (default: @code{shepherd})
  26608. The Shepherd package to use.
  26609. @item services (default: @code{'()})
  26610. A list of @code{<shepherd-service>} to start.
  26611. You should probably use the service extension
  26612. mechanism instead (@pxref{Shepherd Services}).
  26613. @end table
  26614. @end deftp
  26615. The following example specifies the Shepherd package for the operating
  26616. system:
  26617. @lisp
  26618. (operating-system
  26619. ;; ...
  26620. (services (append (list openssh-service-type))
  26621. ;; ...
  26622. %desktop-services)
  26623. ;; ...
  26624. ;; Use own Shepherd package.
  26625. (essential-services
  26626. (modify-services (operating-system-default-essential-services
  26627. this-operating-system)
  26628. (shepherd-root-service-type config => (shepherd-configuration
  26629. (inherit config)
  26630. (shepherd my-shepherd))))))
  26631. @end lisp
  26632. @defvr {Scheme Variable} %shepherd-root-service
  26633. This service represents PID@tie{}1.
  26634. @end defvr
  26635. @node Documentation
  26636. @chapter Documentation
  26637. @cindex documentation, searching for
  26638. @cindex searching for documentation
  26639. @cindex Info, documentation format
  26640. @cindex man pages
  26641. @cindex manual pages
  26642. In most cases packages installed with Guix come with documentation.
  26643. There are two main documentation formats: ``Info'', a browseable
  26644. hypertext format used for GNU software, and ``manual pages'' (or ``man
  26645. pages''), the linear documentation format traditionally found on Unix.
  26646. Info manuals are accessed with the @command{info} command or with Emacs,
  26647. and man pages are accessed using @command{man}.
  26648. You can look for documentation of software installed on your system by
  26649. keyword. For example, the following command searches for information
  26650. about ``TLS'' in Info manuals:
  26651. @example
  26652. $ info -k TLS
  26653. "(emacs)Network Security" -- STARTTLS
  26654. "(emacs)Network Security" -- TLS
  26655. "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
  26656. "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
  26657. @dots{}
  26658. @end example
  26659. @noindent
  26660. The command below searches for the same keyword in man pages:
  26661. @example
  26662. $ man -k TLS
  26663. SSL (7) - OpenSSL SSL/TLS library
  26664. certtool (1) - GnuTLS certificate tool
  26665. @dots {}
  26666. @end example
  26667. These searches are purely local to your computer so you have the
  26668. guarantee that documentation you find corresponds to what you have
  26669. actually installed, you can access it off-line, and your privacy is
  26670. respected.
  26671. Once you have these results, you can view the relevant documentation by
  26672. running, say:
  26673. @example
  26674. $ info "(gnutls)Core TLS API"
  26675. @end example
  26676. @noindent
  26677. or:
  26678. @example
  26679. $ man certtool
  26680. @end example
  26681. Info manuals contain sections and indices as well as hyperlinks like
  26682. those found in Web pages. The @command{info} reader (@pxref{Top, Info
  26683. reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
  26684. (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
  26685. bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
  26686. Introduction}, for an introduction to Info navigation.
  26687. @node Installing Debugging Files
  26688. @chapter Installing Debugging Files
  26689. @cindex debugging files
  26690. Program binaries, as produced by the GCC compilers for instance, are
  26691. typically written in the ELF format, with a section containing
  26692. @dfn{debugging information}. Debugging information is what allows the
  26693. debugger, GDB, to map binary code to source code; it is required to
  26694. debug a compiled program in good conditions.
  26695. This chapter explains how to use separate debug info when packages
  26696. provide it, and how to rebuild packages with debug info when it's
  26697. missing.
  26698. @menu
  26699. * Separate Debug Info:: Installing 'debug' outputs.
  26700. * Rebuilding Debug Info:: Building missing debug info.
  26701. @end menu
  26702. @node Separate Debug Info
  26703. @section Separate Debug Info
  26704. The problem with debugging information is that is takes up a fair amount
  26705. of disk space. For example, debugging information for the GNU C Library
  26706. weighs in at more than 60 MiB@. Thus, as a user, keeping all the
  26707. debugging info of all the installed programs is usually not an option.
  26708. Yet, space savings should not come at the cost of an impediment to
  26709. debugging---especially in the GNU system, which should make it easier
  26710. for users to exert their computing freedom (@pxref{GNU Distribution}).
  26711. Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
  26712. mechanism that allows users to get the best of both worlds: debugging
  26713. information can be stripped from the binaries and stored in separate
  26714. files. GDB is then able to load debugging information from those files,
  26715. when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
  26716. with GDB}).
  26717. The GNU distribution takes advantage of this by storing debugging
  26718. information in the @code{lib/debug} sub-directory of a separate package
  26719. output unimaginatively called @code{debug} (@pxref{Packages with
  26720. Multiple Outputs}). Users can choose to install the @code{debug} output
  26721. of a package when they need it. For instance, the following command
  26722. installs the debugging information for the GNU C Library and for GNU
  26723. Guile:
  26724. @example
  26725. guix install glibc:debug guile:debug
  26726. @end example
  26727. GDB must then be told to look for debug files in the user's profile, by
  26728. setting the @code{debug-file-directory} variable (consider setting it
  26729. from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
  26730. GDB}):
  26731. @example
  26732. (gdb) set debug-file-directory ~/.guix-profile/lib/debug
  26733. @end example
  26734. From there on, GDB will pick up debugging information from the
  26735. @file{.debug} files under @file{~/.guix-profile/lib/debug}.
  26736. In addition, you will most likely want GDB to be able to show the source
  26737. code being debugged. To do that, you will have to unpack the source
  26738. code of the package of interest (obtained with @code{guix build
  26739. --source}, @pxref{Invoking guix build}), and to point GDB to that source
  26740. directory using the @code{directory} command (@pxref{Source Path,
  26741. @code{directory},, gdb, Debugging with GDB}).
  26742. @c XXX: keep me up-to-date
  26743. The @code{debug} output mechanism in Guix is implemented by the
  26744. @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
  26745. opt-in---debugging information is available only for the packages with
  26746. definitions explicitly declaring a @code{debug} output. To check
  26747. whether a package has a @code{debug} output, use @command{guix package
  26748. --list-available} (@pxref{Invoking guix package}).
  26749. Read on for how to deal with packages lacking a @code{debug} output.
  26750. @node Rebuilding Debug Info
  26751. @section Rebuilding Debug Info
  26752. @cindex debugging info, rebuilding
  26753. As we saw above, some packages, but not all, provide debugging info in a
  26754. @code{debug} output. What can you do when debugging info is missing?
  26755. The @option{--with-debug-info} option provides a solution to that: it
  26756. allows you to rebuild the package(s) for which debugging info is
  26757. missing---and only those---and to graft those onto the application
  26758. you're debugging. Thus, while it's not as fast as installing a
  26759. @code{debug} output, it is relatively inexpensive.
  26760. Let's illustrate that. Suppose you're experiencing a bug in Inkscape
  26761. and would like to see what's going on in GLib, a library that's deep
  26762. down in its dependency graph. As it turns out, GLib does not have a
  26763. @code{debug} output and the backtrace GDB shows is all sadness:
  26764. @example
  26765. (gdb) bt
  26766. #0 0x00007ffff5f92190 in g_getenv ()
  26767. from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
  26768. #1 0x00007ffff608a7d6 in gobject_init_ctor ()
  26769. from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
  26770. #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
  26771. env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
  26772. #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
  26773. at dl-init.c:118
  26774. @end example
  26775. To address that, you install Inkscape linked against a variant GLib that
  26776. contains debug info:
  26777. @example
  26778. guix install inkscape --with-debug-info=glib
  26779. @end example
  26780. This time, debugging will be a whole lot nicer:
  26781. @example
  26782. $ gdb --args sh -c 'exec inkscape'
  26783. @dots{}
  26784. (gdb) b g_getenv
  26785. Function "g_getenv" not defined.
  26786. Make breakpoint pending on future shared library load? (y or [n]) y
  26787. Breakpoint 1 (g_getenv) pending.
  26788. (gdb) r
  26789. Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
  26790. @dots{}
  26791. (gdb) bt
  26792. #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
  26793. #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
  26794. #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
  26795. #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
  26796. env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
  26797. @dots{}
  26798. @end example
  26799. Much better!
  26800. Note that there can be packages for which @option{--with-debug-info}
  26801. will not have the desired effect. @xref{Package Transformation Options,
  26802. @option{--with-debug-info}}, for more information.
  26803. @node Security Updates
  26804. @chapter Security Updates
  26805. @cindex security updates
  26806. @cindex security vulnerabilities
  26807. Occasionally, important security vulnerabilities are discovered in software
  26808. packages and must be patched. Guix developers try hard to keep track of
  26809. known vulnerabilities and to apply fixes as soon as possible in the
  26810. @code{master} branch of Guix (we do not yet provide a ``stable'' branch
  26811. containing only security updates). The @command{guix lint} tool helps
  26812. developers find out about vulnerable versions of software packages in the
  26813. distribution:
  26814. @smallexample
  26815. $ guix lint -c cve
  26816. gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
  26817. gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
  26818. gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
  26819. @dots{}
  26820. @end smallexample
  26821. @xref{Invoking guix lint}, for more information.
  26822. Guix follows a functional
  26823. package management discipline (@pxref{Introduction}), which implies
  26824. that, when a package is changed, @emph{every package that depends on it}
  26825. must be rebuilt. This can significantly slow down the deployment of
  26826. fixes in core packages such as libc or Bash, since basically the whole
  26827. distribution would need to be rebuilt. Using pre-built binaries helps
  26828. (@pxref{Substitutes}), but deployment may still take more time than
  26829. desired.
  26830. @cindex grafts
  26831. To address this, Guix implements @dfn{grafts}, a mechanism that allows
  26832. for fast deployment of critical updates without the costs associated
  26833. with a whole-distribution rebuild. The idea is to rebuild only the
  26834. package that needs to be patched, and then to ``graft'' it onto packages
  26835. explicitly installed by the user and that were previously referring to
  26836. the original package. The cost of grafting is typically very low, and
  26837. order of magnitudes lower than a full rebuild of the dependency chain.
  26838. @cindex replacements of packages, for grafts
  26839. For instance, suppose a security update needs to be applied to Bash.
  26840. Guix developers will provide a package definition for the ``fixed''
  26841. Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
  26842. Packages}). Then, the original package definition is augmented with a
  26843. @code{replacement} field pointing to the package containing the bug fix:
  26844. @lisp
  26845. (define bash
  26846. (package
  26847. (name "bash")
  26848. ;; @dots{}
  26849. (replacement bash-fixed)))
  26850. @end lisp
  26851. From there on, any package depending directly or indirectly on Bash---as
  26852. reported by @command{guix gc --requisites} (@pxref{Invoking guix
  26853. gc})---that is installed is automatically ``rewritten'' to refer to
  26854. @code{bash-fixed} instead of @code{bash}. This grafting process takes
  26855. time proportional to the size of the package, usually less than a
  26856. minute for an ``average'' package on a recent machine. Grafting is
  26857. recursive: when an indirect dependency requires grafting, then grafting
  26858. ``propagates'' up to the package that the user is installing.
  26859. Currently, the length of the name and version of the graft and that of
  26860. the package it replaces (@code{bash-fixed} and @code{bash} in the example
  26861. above) must be equal. This restriction mostly comes from the fact that
  26862. grafting works by patching files, including binary files, directly.
  26863. Other restrictions may apply: for instance, when adding a graft to a
  26864. package providing a shared library, the original shared library and its
  26865. replacement must have the same @code{SONAME} and be binary-compatible.
  26866. The @option{--no-grafts} command-line option allows you to forcefully
  26867. avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
  26868. Thus, the command:
  26869. @example
  26870. guix build bash --no-grafts
  26871. @end example
  26872. @noindent
  26873. returns the store file name of the original Bash, whereas:
  26874. @example
  26875. guix build bash
  26876. @end example
  26877. @noindent
  26878. returns the store file name of the ``fixed'', replacement Bash. This
  26879. allows you to distinguish between the two variants of Bash.
  26880. To verify which Bash your whole profile refers to, you can run
  26881. (@pxref{Invoking guix gc}):
  26882. @example
  26883. guix gc -R `readlink -f ~/.guix-profile` | grep bash
  26884. @end example
  26885. @noindent
  26886. @dots{} and compare the store file names that you get with those above.
  26887. Likewise for a complete Guix system generation:
  26888. @example
  26889. guix gc -R `guix system build my-config.scm` | grep bash
  26890. @end example
  26891. Lastly, to check which Bash running processes are using, you can use the
  26892. @command{lsof} command:
  26893. @example
  26894. lsof | grep /gnu/store/.*bash
  26895. @end example
  26896. @node Bootstrapping
  26897. @chapter Bootstrapping
  26898. @c Adapted from the ELS 2013 paper.
  26899. @cindex bootstrapping
  26900. Bootstrapping in our context refers to how the distribution gets built
  26901. ``from nothing''. Remember that the build environment of a derivation
  26902. contains nothing but its declared inputs (@pxref{Introduction}). So
  26903. there's an obvious chicken-and-egg problem: how does the first package
  26904. get built? How does the first compiler get compiled?
  26905. It is tempting to think of this question as one that only die-hard
  26906. hackers may care about. However, while the answer to that question is
  26907. technical in nature, its implications are wide-ranging. How the
  26908. distribution is bootstrapped defines the extent to which we, as
  26909. individuals and as a collective of users and hackers, can trust the
  26910. software we run. It is a central concern from the standpoint of
  26911. @emph{security} and from a @emph{user freedom} viewpoint.
  26912. @cindex bootstrap binaries
  26913. The GNU system is primarily made of C code, with libc at its core. The
  26914. GNU build system itself assumes the availability of a Bourne shell and
  26915. command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
  26916. `grep'. Furthermore, build programs---programs that run
  26917. @code{./configure}, @code{make}, etc.---are written in Guile Scheme
  26918. (@pxref{Derivations}). Consequently, to be able to build anything at
  26919. all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
  26920. Binutils, libc, and the other packages mentioned above---the
  26921. @dfn{bootstrap binaries}.
  26922. These bootstrap binaries are ``taken for granted'', though we can also
  26923. re-create them if needed (@pxref{Preparing to Use the Bootstrap
  26924. Binaries}).
  26925. @menu
  26926. * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
  26927. * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
  26928. @end menu
  26929. @node Reduced Binary Seed Bootstrap
  26930. @section The Reduced Binary Seed Bootstrap
  26931. Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
  26932. a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
  26933. Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
  26934. GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
  26935. ``taken for granted.''
  26936. Taking the bootstrap binaries for granted means that we consider them to
  26937. be a correct and trustworthy ``seed'' for building the complete system.
  26938. Therein lies a problem: the combined size of these bootstrap binaries is
  26939. about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
  26940. or even inspecting these is next to impossible.
  26941. For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
  26942. ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
  26943. Source Bootstrap'' and while we are working towards that goal it would
  26944. be hyperbole to use that term for what we do now.}.
  26945. The Reduced Binary Seed bootstrap removes the most critical tools---from a
  26946. trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
  26947. Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
  26948. linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
  26949. written in Scheme and the Mes C Library, built for TinyCC and for GCC).
  26950. Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
  26951. C Library are built from source. From here on the more traditional
  26952. bootstrap process resumes. This approach has reduced the bootstrap
  26953. binaries in size to about 145MB in Guix v1.1.
  26954. The next step that Guix has taken is to replace the shell and all its
  26955. utilities with implementations in Guile Scheme, the @emph{Scheme-only
  26956. bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
  26957. POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
  26958. which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
  26959. Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
  26960. removed are now built from source.
  26961. Building the GNU System from source is currently only possible by adding
  26962. some historical GNU packages as intermediate steps@footnote{Packages
  26963. such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
  26964. @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
  26965. @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
  26966. and GNU packages become more bootstrappable again (e.g., new releases of
  26967. GNU Sed will also ship as gzipped tarballs again, as alternative to the
  26968. hard to bootstrap @code{xz}-compression), this set of added packages can
  26969. hopefully be reduced again.
  26970. The graph below shows the resulting dependency graph for
  26971. @code{gcc-core-mesboot0}, the bootstrap compiler used for the
  26972. traditional bootstrap of the rest of the Guix System.
  26973. @c ./pre-inst-env guix graph -e '(@@ (gnu packages commencement) gcc-core-mesboot0)' | sed -re 's,((bootstrap-mescc-tools|bootstrap-mes|guile-bootstrap).*shape =) box,\1 ellipse,' > doc/images/gcc-core-mesboot0-graph.dot
  26974. @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
  26975. The only significant binary bootstrap seeds that remain@footnote{
  26976. Ignoring the 68KB @code{mescc-tools}; that will be removed later,
  26977. together with @code{mes}.} are a Scheme intepreter and a Scheme
  26978. compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
  26979. static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
  26980. to get Guile running.}.
  26981. This further reduction has brought down the size of the binary seed to
  26982. about 60MB for @code{i686-linux} and @code{x86_64-linux}.
  26983. Work is ongoing to remove all binary blobs from our free software
  26984. bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
  26985. is work to bring these bootstraps to the @code{arm-linux} and
  26986. @code{aarch64-linux} architectures and to the Hurd.
  26987. If you are interested, join us on @samp{#bootstrappable} on the Freenode
  26988. IRC network or discuss on @email{bug-mes@@gnu.org} or
  26989. @email{gash-devel@@nongnu.org}.
  26990. @node Preparing to Use the Bootstrap Binaries
  26991. @section Preparing to Use the Bootstrap Binaries
  26992. @c As of Emacs 24.3, Info-mode displays the image, but since it's a
  26993. @c large image, it's hard to scroll. Oh well.
  26994. @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
  26995. The figure above shows the very beginning of the dependency graph of the
  26996. distribution, corresponding to the package definitions of the @code{(gnu
  26997. packages bootstrap)} module. A similar figure can be generated with
  26998. @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
  26999. @example
  27000. guix graph -t derivation \
  27001. -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
  27002. | dot -Tps > gcc.ps
  27003. @end example
  27004. or, for the further Reduced Binary Seed bootstrap
  27005. @example
  27006. guix graph -t derivation \
  27007. -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
  27008. | dot -Tps > mes.ps
  27009. @end example
  27010. At this level of detail, things are
  27011. slightly complex. First, Guile itself consists of an ELF executable,
  27012. along with many source and compiled Scheme files that are dynamically
  27013. loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
  27014. tarball shown in this graph. This tarball is part of Guix's ``source''
  27015. distribution, and gets inserted into the store with @code{add-to-store}
  27016. (@pxref{The Store}).
  27017. But how do we write a derivation that unpacks this tarball and adds it
  27018. to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
  27019. derivation---the first one that gets built---uses @code{bash} as its
  27020. builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
  27021. @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
  27022. @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
  27023. the Guix source distribution, whose sole purpose is to allow the Guile
  27024. tarball to be unpacked.
  27025. Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
  27026. Guile that can be used to run subsequent build programs. Its first task
  27027. is to download tarballs containing the other pre-built binaries---this
  27028. is what the @file{.tar.xz.drv} derivations do. Guix modules such as
  27029. @code{ftp-client.scm} are used for this purpose. The
  27030. @code{module-import.drv} derivations import those modules in a directory
  27031. in the store, using the original layout. The
  27032. @code{module-import-compiled.drv} derivations compile those modules, and
  27033. write them in an output directory with the right layout. This
  27034. corresponds to the @code{#:modules} argument of
  27035. @code{build-expression->derivation} (@pxref{Derivations}).
  27036. Finally, the various tarballs are unpacked by the derivations
  27037. @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
  27038. @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
  27039. point we have a working C tool chain.
  27040. @unnumberedsec Building the Build Tools
  27041. Bootstrapping is complete when we have a full tool chain that does not
  27042. depend on the pre-built bootstrap tools discussed above. This
  27043. no-dependency requirement is verified by checking whether the files of
  27044. the final tool chain contain references to the @file{/gnu/store}
  27045. directories of the bootstrap inputs. The process that leads to this
  27046. ``final'' tool chain is described by the package definitions found in
  27047. the @code{(gnu packages commencement)} module.
  27048. The @command{guix graph} command allows us to ``zoom out'' compared to
  27049. the graph above, by looking at the level of package objects instead of
  27050. individual derivations---remember that a package may translate to
  27051. several derivations, typically one derivation to download its source,
  27052. one to build the Guile modules it needs, and one to actually build the
  27053. package from source. The command:
  27054. @example
  27055. guix graph -t bag \
  27056. -e '(@@@@ (gnu packages commencement)
  27057. glibc-final-with-bootstrap-bash)' | xdot -
  27058. @end example
  27059. @noindent
  27060. displays the dependency graph leading to the ``final'' C
  27061. library@footnote{You may notice the @code{glibc-intermediate} label,
  27062. suggesting that it is not @emph{quite} final, but as a good
  27063. approximation, we will consider it final.}, depicted below.
  27064. @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
  27065. @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
  27066. The first tool that gets built with the bootstrap binaries is
  27067. GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
  27068. for all the following packages. From there Findutils and Diffutils get
  27069. built.
  27070. Then come the first-stage Binutils and GCC, built as pseudo cross
  27071. tools---i.e., with @option{--target} equal to @option{--host}. They are
  27072. used to build libc. Thanks to this cross-build trick, this libc is
  27073. guaranteed not to hold any reference to the initial tool chain.
  27074. From there the final Binutils and GCC (not shown above) are built. GCC
  27075. uses @command{ld} from the final Binutils, and links programs against
  27076. the just-built libc. This tool chain is used to build the other
  27077. packages used by Guix and by the GNU Build System: Guile, Bash,
  27078. Coreutils, etc.
  27079. And voilà! At this point we have the complete set of build tools that
  27080. the GNU Build System expects. These are in the @code{%final-inputs}
  27081. variable of the @code{(gnu packages commencement)} module, and are
  27082. implicitly used by any package that uses @code{gnu-build-system}
  27083. (@pxref{Build Systems, @code{gnu-build-system}}).
  27084. @unnumberedsec Building the Bootstrap Binaries
  27085. @cindex bootstrap binaries
  27086. Because the final tool chain does not depend on the bootstrap binaries,
  27087. those rarely need to be updated. Nevertheless, it is useful to have an
  27088. automated way to produce them, should an update occur, and this is what
  27089. the @code{(gnu packages make-bootstrap)} module provides.
  27090. The following command builds the tarballs containing the bootstrap binaries
  27091. (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
  27092. bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
  27093. and Guile, and a tarball containing a mixture of Coreutils and other basic
  27094. command-line tools):
  27095. @example
  27096. guix build bootstrap-tarballs
  27097. @end example
  27098. The generated tarballs are those that should be referred to in the
  27099. @code{(gnu packages bootstrap)} module mentioned at the beginning of
  27100. this section.
  27101. Still here? Then perhaps by now you've started to wonder: when do we
  27102. reach a fixed point? That is an interesting question! The answer is
  27103. unknown, but if you would like to investigate further (and have
  27104. significant computational and storage resources to do so), then let us
  27105. know.
  27106. @unnumberedsec Reducing the Set of Bootstrap Binaries
  27107. Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
  27108. binary code! Why is that a problem? It's a problem because these big chunks
  27109. of binary code are practically non-auditable, which makes it hard to establish
  27110. what source code produced them. Every unauditable binary also leaves us
  27111. vulnerable to compiler backdoors as described by Ken Thompson in the 1984
  27112. paper @emph{Reflections on Trusting Trust}.
  27113. This is mitigated by the fact that our bootstrap binaries were generated
  27114. from an earlier Guix revision. Nevertheless it lacks the level of
  27115. transparency that we get in the rest of the package dependency graph,
  27116. where Guix always gives us a source-to-binary mapping. Thus, our goal
  27117. is to reduce the set of bootstrap binaries to the bare minimum.
  27118. The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
  27119. on-going projects to do that. One of these is about replacing the
  27120. bootstrap GCC with a sequence of assemblers, interpreters, and compilers
  27121. of increasing complexity, which could be built from source starting from
  27122. a simple and auditable assembler.
  27123. Our first major achievement is the replacement of of GCC, the GNU C Library
  27124. and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
  27125. (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
  27126. and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
  27127. bootstrapped yet and thus we inject them as binary seeds. We call this the
  27128. Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
  27129. binaries! Also, it has eliminated the C compiler binary; i686-linux and
  27130. x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
  27131. Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
  27132. also looking at any other bootstrap binaries. Your help is welcome!
  27133. @node Porting
  27134. @chapter Porting to a New Platform
  27135. As discussed above, the GNU distribution is self-contained, and
  27136. self-containment is achieved by relying on pre-built ``bootstrap
  27137. binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
  27138. operating system kernel, CPU architecture, and application binary
  27139. interface (ABI). Thus, to port the distribution to a platform that is
  27140. not yet supported, one must build those bootstrap binaries, and update
  27141. the @code{(gnu packages bootstrap)} module to use them on that platform.
  27142. Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
  27143. When everything goes well, and assuming the GNU tool chain supports the
  27144. target platform, this can be as simple as running a command like this
  27145. one:
  27146. @example
  27147. guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
  27148. @end example
  27149. For this to work, the @code{glibc-dynamic-linker} procedure in
  27150. @code{(gnu packages bootstrap)} must be augmented to return the right
  27151. file name for libc's dynamic linker on that platform; likewise,
  27152. @code{system->linux-architecture} in @code{(gnu packages linux)} must be
  27153. taught about the new platform.
  27154. Once these are built, the @code{(gnu packages bootstrap)} module needs
  27155. to be updated to refer to these binaries on the target platform. That
  27156. is, the hashes and URLs of the bootstrap tarballs for the new platform
  27157. must be added alongside those of the currently supported platforms. The
  27158. bootstrap Guile tarball is treated specially: it is expected to be
  27159. available locally, and @file{gnu/local.mk} has rules to download it for
  27160. the supported architectures; a rule for the new platform must be added
  27161. as well.
  27162. In practice, there may be some complications. First, it may be that the
  27163. extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
  27164. above) is not recognized by all the GNU tools. Typically, glibc
  27165. recognizes some of these, whereas GCC uses an extra @option{--with-abi}
  27166. configure flag (see @code{gcc.scm} for examples of how to handle this).
  27167. Second, some of the required packages could fail to build for that
  27168. platform. Lastly, the generated binaries could be broken for some
  27169. reason.
  27170. @c *********************************************************************
  27171. @include contributing.texi
  27172. @c *********************************************************************
  27173. @node Acknowledgments
  27174. @chapter Acknowledgments
  27175. Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
  27176. which was designed and
  27177. implemented by Eelco Dolstra, with contributions from other people (see
  27178. the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
  27179. management, and promoted unprecedented features, such as transactional
  27180. package upgrades and rollbacks, per-user profiles, and referentially
  27181. transparent build processes. Without this work, Guix would not exist.
  27182. The Nix-based software distributions, Nixpkgs and NixOS, have also been
  27183. an inspiration for Guix.
  27184. GNU@tie{}Guix itself is a collective work with contributions from a
  27185. number of people. See the @file{AUTHORS} file in Guix for more
  27186. information on these fine people. The @file{THANKS} file lists people
  27187. who have helped by reporting bugs, taking care of the infrastructure,
  27188. providing artwork and themes, making suggestions, and more---thank you!
  27189. @c *********************************************************************
  27190. @node GNU Free Documentation License
  27191. @appendix GNU Free Documentation License
  27192. @cindex license, GNU Free Documentation License
  27193. @include fdl-1.3.texi
  27194. @c *********************************************************************
  27195. @node Concept Index
  27196. @unnumbered Concept Index
  27197. @printindex cp
  27198. @node Programming Index
  27199. @unnumbered Programming Index
  27200. @syncodeindex tp fn
  27201. @syncodeindex vr fn
  27202. @printindex fn
  27203. @bye
  27204. @c Local Variables:
  27205. @c ispell-local-dictionary: "american";
  27206. @c End: