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 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 Christopher Allan 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{} 2021 Maxime Devos@*
  84. Permission is granted to copy, distribute and/or modify this document
  85. under the terms of the GNU Free Documentation License, Version 1.3 or
  86. any later version published by the Free Software Foundation; with no
  87. Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
  88. copy of the license is included in the section entitled ``GNU Free
  89. Documentation License''.
  90. @end copying
  91. @dircategory System administration
  92. @direntry
  93. * Guix: (guix). Manage installed software and system configuration.
  94. * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
  95. * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
  96. * guix pull: (guix)Invoking guix pull. Update the list of available packages.
  97. * guix system: (guix)Invoking guix system. Manage the operating system configuration.
  98. * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
  99. @end direntry
  100. @dircategory Software development
  101. @direntry
  102. * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
  103. * guix build: (guix)Invoking guix build. Building packages.
  104. * guix pack: (guix)Invoking guix pack. Creating binary bundles.
  105. @end direntry
  106. @titlepage
  107. @title GNU Guix Reference Manual
  108. @subtitle Using the GNU Guix Functional Package Manager
  109. @author The GNU Guix Developers
  110. @page
  111. @vskip 0pt plus 1filll
  112. Edition @value{EDITION} @*
  113. @value{UPDATED} @*
  114. @insertcopying
  115. @end titlepage
  116. @contents
  117. @c *********************************************************************
  118. @node Top
  119. @top GNU Guix
  120. This document describes GNU Guix version @value{VERSION}, a functional
  121. package management tool written for the GNU system.
  122. @c TRANSLATORS: You can replace the following paragraph with information on
  123. @c how to join your own translation team and how to report issues with the
  124. @c translation.
  125. This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
  126. GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
  127. Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
  128. Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
  129. Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
  130. would like to translate it in your native language, consider joining
  131. @uref{https://translate.fedoraproject.org/projects/guix/documentation-manual,
  132. Weblate}.
  133. @menu
  134. * Introduction:: What is Guix about?
  135. * Installation:: Installing Guix.
  136. * System Installation:: Installing the whole operating system.
  137. * Getting Started:: Your first steps.
  138. * Package Management:: Package installation, upgrade, etc.
  139. * Channels:: Customizing the package collection.
  140. * Development:: Guix-aided software development.
  141. * Programming Interface:: Using Guix in Scheme.
  142. * Utilities:: Package management commands.
  143. * System Configuration:: Configuring the operating system.
  144. * Documentation:: Browsing software user manuals.
  145. * Installing Debugging Files:: Feeding the debugger.
  146. * Security Updates:: Deploying security fixes quickly.
  147. * Bootstrapping:: GNU/Linux built from scratch.
  148. * Porting:: Targeting another platform or kernel.
  149. * Contributing:: Your help needed!
  150. * Acknowledgments:: Thanks!
  151. * GNU Free Documentation License:: The license of this manual.
  152. * Concept Index:: Concepts.
  153. * Programming Index:: Data types, functions, and variables.
  154. @detailmenu
  155. --- The Detailed Node Listing ---
  156. Introduction
  157. * Managing Software the Guix Way:: What's special.
  158. * GNU Distribution:: The packages and tools.
  159. Installation
  160. * Binary Installation:: Getting Guix running in no time!
  161. * Requirements:: Software needed to build and run Guix.
  162. * Running the Test Suite:: Testing Guix.
  163. * Setting Up the Daemon:: Preparing the build daemon's environment.
  164. * Invoking guix-daemon:: Running the build daemon.
  165. * Application Setup:: Application-specific setup.
  166. * Upgrading Guix:: Upgrading Guix and its build daemon.
  167. Setting Up the Daemon
  168. * Build Environment Setup:: Preparing the isolated build environment.
  169. * Daemon Offload Setup:: Offloading builds to remote machines.
  170. * SELinux Support:: Using an SELinux policy for the daemon.
  171. System Installation
  172. * Limitations:: What you can expect.
  173. * Hardware Considerations:: Supported hardware.
  174. * USB Stick and DVD Installation:: Preparing the installation medium.
  175. * Preparing for Installation:: Networking, partitioning, etc.
  176. * Guided Graphical Installation:: Easy graphical installation.
  177. * Manual Installation:: Manual installation for wizards.
  178. * After System Installation:: When installation succeeded.
  179. * Installing Guix in a VM:: Guix System playground.
  180. * Building the Installation Image:: How this comes to be.
  181. Manual Installation
  182. * Keyboard Layout and Networking and Partitioning:: Initial setup.
  183. * Proceeding with the Installation:: Installing.
  184. Package Management
  185. * Features:: How Guix will make your life brighter.
  186. * Invoking guix package:: Package installation, removal, etc.
  187. * Substitutes:: Downloading pre-built binaries.
  188. * Packages with Multiple Outputs:: Single source package, multiple outputs.
  189. * Invoking guix gc:: Running the garbage collector.
  190. * Invoking guix pull:: Fetching the latest Guix and distribution.
  191. * Invoking guix time-machine:: Running an older revision of Guix.
  192. * Inferiors:: Interacting with another revision of Guix.
  193. * Invoking guix describe:: Display information about your Guix revision.
  194. * Invoking guix archive:: Exporting and importing store files.
  195. Substitutes
  196. * Official Substitute Server:: One particular source of substitutes.
  197. * Substitute Server Authorization:: How to enable or disable substitutes.
  198. * Getting Substitutes from Other Servers:: Substitute diversity.
  199. * Getting Substitutes from Other Protocols:: Different sources of substitutes.
  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 Substituters:: Defining new substitution methods.
  234. Defining Packages
  235. * package Reference:: The package data type.
  236. * origin Reference:: The origin data type.
  237. Utilities
  238. * Invoking guix build:: Building packages from the command line.
  239. * Invoking guix edit:: Editing package definitions.
  240. * Invoking guix download:: Downloading a file and printing its hash.
  241. * Invoking guix hash:: Computing the cryptographic hash of a file.
  242. * Invoking guix import:: Importing package definitions.
  243. * Invoking guix refresh:: Updating package definitions.
  244. * Invoking guix lint:: Finding errors in package definitions.
  245. * Invoking guix size:: Profiling disk usage.
  246. * Invoking guix graph:: Visualizing the graph of packages.
  247. * Invoking guix publish:: Sharing substitutes.
  248. * Invoking guix challenge:: Challenging substitute servers.
  249. * Invoking guix copy:: Copying to and from a remote store.
  250. * Invoking guix container:: Process isolation.
  251. * Invoking guix weather:: Assessing substitute availability.
  252. * Invoking guix processes:: Listing client processes.
  253. Invoking @command{guix build}
  254. * Common Build Options:: Build options for most commands.
  255. * Package Transformation Options:: Creating variants of packages.
  256. * Additional Build Options:: Options specific to 'guix build'.
  257. * Debugging Build Failures:: Real life packaging experience.
  258. System Configuration
  259. * Using the Configuration System:: Customizing your GNU system.
  260. * operating-system Reference:: Detail of operating-system declarations.
  261. * File Systems:: Configuring file system mounts.
  262. * Mapped Devices:: Block device extra processing.
  263. * User Accounts:: Specifying user accounts.
  264. * Keyboard Layout:: How the system interprets key strokes.
  265. * Locales:: Language and cultural convention settings.
  266. * Services:: Specifying system services.
  267. * Setuid Programs:: Programs running with root privileges.
  268. * X.509 Certificates:: Authenticating HTTPS servers.
  269. * Name Service Switch:: Configuring libc's name service switch.
  270. * Initial RAM Disk:: Linux-Libre bootstrapping.
  271. * Bootloader Configuration:: Configuring the boot loader.
  272. * Invoking guix system:: Instantiating a system configuration.
  273. * Invoking guix deploy:: Deploying a system configuration to a remote host.
  274. * Running Guix in a VM:: How to run Guix System in a virtual machine.
  275. * Defining Services:: Adding new service definitions.
  276. Services
  277. * Base Services:: Essential system services.
  278. * Scheduled Job Execution:: The mcron service.
  279. * Log Rotation:: The rottlog service.
  280. * Networking Services:: Network setup, SSH daemon, etc.
  281. * Unattended Upgrades:: Automated system upgrades.
  282. * X Window:: Graphical display.
  283. * Printing Services:: Local and remote printer support.
  284. * Desktop Services:: D-Bus and desktop services.
  285. * Sound Services:: ALSA and Pulseaudio services.
  286. * Database Services:: SQL databases, key-value stores, etc.
  287. * Mail Services:: IMAP, POP3, SMTP, and all that.
  288. * Messaging Services:: Messaging services.
  289. * Telephony Services:: Telephony services.
  290. * Monitoring Services:: Monitoring services.
  291. * Kerberos Services:: Kerberos services.
  292. * LDAP Services:: LDAP services.
  293. * Web Services:: Web servers.
  294. * Certificate Services:: TLS certificates via Let's Encrypt.
  295. * DNS Services:: DNS daemons.
  296. * VPN Services:: VPN daemons.
  297. * Network File System:: NFS related services.
  298. * Continuous Integration:: The Cuirass service.
  299. * Power Management Services:: Extending battery life.
  300. * Audio Services:: The MPD.
  301. * Virtualization Services:: Virtualization services.
  302. * Version Control Services:: Providing remote access to Git repositories.
  303. * Game Services:: Game servers.
  304. * PAM Mount Service:: Service to mount volumes when logging in.
  305. * Guix Services:: Services relating specifically to Guix.
  306. * Linux Services:: Services tied to the Linux kernel.
  307. * Hurd Services:: Services specific for a Hurd System.
  308. * Miscellaneous Services:: Other services.
  309. Defining Services
  310. * Service Composition:: The model for composing services.
  311. * Service Types and Services:: Types and services.
  312. * Service Reference:: API reference.
  313. * Shepherd Services:: A particular type of service.
  314. Installing Debugging Files
  315. * Separate Debug Info:: Installing 'debug' outputs.
  316. * Rebuilding Debug Info:: Building missing debug info.
  317. Bootstrapping
  318. * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
  319. * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
  320. @end detailmenu
  321. @end menu
  322. @c *********************************************************************
  323. @node Introduction
  324. @chapter Introduction
  325. @cindex purpose
  326. GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
  327. using the international phonetic alphabet (IPA).} is a package
  328. management tool for and distribution of the GNU system.
  329. Guix makes it easy for unprivileged
  330. users to install, upgrade, or remove software packages, to roll back to a
  331. previous package set, to build packages from source, and generally
  332. assists with the creation and maintenance of software environments.
  333. @cindex Guix System
  334. @cindex GuixSD, now Guix System
  335. @cindex Guix System Distribution, now Guix System
  336. You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
  337. complements the available tools without interference (@pxref{Installation}),
  338. or you can use it as a standalone operating system distribution,
  339. @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
  340. System Distribution'' or ``GuixSD''. We now consider it makes more sense to
  341. group everything under the ``Guix'' banner since, after all, Guix System is
  342. readily available through the @command{guix system} command, even if you're
  343. using a different distro underneath!}. @xref{GNU Distribution}.
  344. @menu
  345. * Managing Software the Guix Way:: What's special.
  346. * GNU Distribution:: The packages and tools.
  347. @end menu
  348. @node Managing Software the Guix Way
  349. @section Managing Software the Guix Way
  350. @cindex user interfaces
  351. Guix provides a command-line package management interface
  352. (@pxref{Package Management}), tools to help with software development
  353. (@pxref{Development}), command-line utilities for more advanced usage
  354. (@pxref{Utilities}), as well as Scheme programming interfaces
  355. (@pxref{Programming Interface}).
  356. @cindex build daemon
  357. Its @dfn{build daemon} is responsible for building packages on behalf of
  358. users (@pxref{Setting Up the Daemon}) and for downloading pre-built
  359. binaries from authorized sources (@pxref{Substitutes}).
  360. @cindex extensibility of the distribution
  361. @cindex customization, of packages
  362. Guix includes package definitions for many GNU and non-GNU packages, all
  363. of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
  364. user's computing freedom}. It is @emph{extensible}: users can write
  365. their own package definitions (@pxref{Defining Packages}) and make them
  366. available as independent package modules (@pxref{Package Modules}). It
  367. is also @emph{customizable}: users can @emph{derive} specialized package
  368. definitions from existing ones, including from the command line
  369. (@pxref{Package Transformation Options}).
  370. @cindex functional package management
  371. @cindex isolation
  372. Under the hood, Guix implements the @dfn{functional package management}
  373. discipline pioneered by Nix (@pxref{Acknowledgments}).
  374. In Guix, the package build and installation process is seen
  375. as a @emph{function}, in the mathematical sense. That function takes inputs,
  376. such as build scripts, a compiler, and libraries, and
  377. returns an installed package. As a pure function, its result depends
  378. solely on its inputs---for instance, it cannot refer to software or
  379. scripts that were not explicitly passed as inputs. A build function
  380. always produces the same result when passed a given set of inputs. It
  381. cannot alter the environment of the running system in
  382. any way; for instance, it cannot create, modify, or delete files outside
  383. of its build and installation directories. This is achieved by running
  384. build processes in isolated environments (or @dfn{containers}), where only their
  385. explicit inputs are visible.
  386. @cindex store
  387. The result of package build functions is @dfn{cached} in the file
  388. system, in a special directory called @dfn{the store} (@pxref{The
  389. Store}). Each package is installed in a directory of its own in the
  390. store---by default under @file{/gnu/store}. The directory name contains
  391. a hash of all the inputs used to build that package; thus, changing an
  392. input yields a different directory name.
  393. This approach is the foundation for the salient features of Guix: support
  394. for transactional package upgrade and rollback, per-user installation, and
  395. garbage collection of packages (@pxref{Features}).
  396. @node GNU Distribution
  397. @section GNU Distribution
  398. @cindex Guix System
  399. Guix comes with a distribution of the GNU system consisting entirely of
  400. free software@footnote{The term ``free'' here refers to the
  401. @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
  402. users of that software}.}. The
  403. distribution can be installed on its own (@pxref{System Installation}),
  404. but it is also possible to install Guix as a package manager on top of
  405. an installed GNU/Linux system (@pxref{Installation}). When we need to
  406. distinguish between the two, we refer to the standalone distribution as
  407. Guix@tie{}System.
  408. The distribution provides core GNU packages such as GNU libc, GCC, and
  409. Binutils, as well as many GNU and non-GNU applications. The complete
  410. list of available packages can be browsed
  411. @url{https://www.gnu.org/software/guix/packages,on-line} or by
  412. running @command{guix package} (@pxref{Invoking guix package}):
  413. @example
  414. guix package --list-available
  415. @end example
  416. Our goal is to provide a practical 100% free software distribution of
  417. Linux-based and other variants of GNU, with a focus on the promotion and
  418. tight integration of GNU components, and an emphasis on programs and
  419. tools that help users exert that freedom.
  420. Packages are currently available on the following platforms:
  421. @table @code
  422. @item x86_64-linux
  423. Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
  424. @item i686-linux
  425. Intel 32-bit architecture (IA32), Linux-Libre kernel.
  426. @item armhf-linux
  427. ARMv7-A architecture with hard float, Thumb-2 and NEON,
  428. using the EABI hard-float application binary interface (ABI),
  429. and Linux-Libre kernel.
  430. @item aarch64-linux
  431. little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
  432. @item i586-gnu
  433. @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
  434. (IA32).
  435. This configuration is experimental and under development. The easiest
  436. way for you to give it a try is by setting up an instance of
  437. @code{hurd-vm-service-type} on your GNU/Linux machine
  438. (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
  439. @xref{Contributing}, on how to help!
  440. @item mips64el-linux (deprecated)
  441. little-endian 64-bit MIPS processors, specifically the Loongson series,
  442. n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
  443. supported; in particular, there is no ongoing work to ensure that this
  444. architecture still works. Should someone decide they wish to revive this
  445. architecture then the code is still available.
  446. @end table
  447. With Guix@tie{}System, you @emph{declare} all aspects of the operating system
  448. configuration and Guix takes care of instantiating the configuration in a
  449. transactional, reproducible, and stateless fashion (@pxref{System
  450. Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
  451. initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
  452. Manual}), the well-known GNU utilities and tool chain, as well as the
  453. graphical environment or system services of your choice.
  454. Guix System is available on all the above platforms except
  455. @code{mips64el-linux}.
  456. @noindent
  457. For information on porting to other architectures or kernels,
  458. @pxref{Porting}.
  459. Building this distribution is a cooperative effort, and you are invited
  460. to join! @xref{Contributing}, for information about how you can help.
  461. @c *********************************************************************
  462. @node Installation
  463. @chapter Installation
  464. @cindex installing Guix
  465. @quotation Note
  466. We recommend the use of this
  467. @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
  468. shell installer script} to install Guix on top of a running GNU/Linux system,
  469. thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
  470. with the installation of the package manager, which can be done on top of a
  471. running GNU/Linux system. If, instead, you want to install the complete GNU
  472. operating system, @pxref{System Installation}.} The script automates the
  473. download, installation, and initial configuration of Guix. It should be run
  474. as the root user.
  475. @end quotation
  476. @cindex foreign distro
  477. @cindex directories related to foreign distro
  478. When installed on a foreign distro, GNU@tie{}Guix complements the available
  479. tools without interference. Its data lives exclusively in two directories,
  480. usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
  481. such as @file{/etc}, are left untouched.
  482. Once installed, Guix can be updated by running @command{guix pull}
  483. (@pxref{Invoking guix pull}).
  484. If you prefer to perform the installation steps manually or want to tweak
  485. them, you may find the following subsections useful. They describe the
  486. software requirements of Guix, as well as how to install it manually and get
  487. ready to use it.
  488. @menu
  489. * Binary Installation:: Getting Guix running in no time!
  490. * Requirements:: Software needed to build and run Guix.
  491. * Running the Test Suite:: Testing Guix.
  492. * Setting Up the Daemon:: Preparing the build daemon's environment.
  493. * Invoking guix-daemon:: Running the build daemon.
  494. * Application Setup:: Application-specific setup.
  495. * Upgrading Guix:: Upgrading Guix and its build daemon.
  496. @end menu
  497. @node Binary Installation
  498. @section Binary Installation
  499. @cindex installing Guix from binaries
  500. @cindex installer script
  501. This section describes how to install Guix on an arbitrary system from a
  502. self-contained tarball providing binaries for Guix and for all its
  503. dependencies. This is often quicker than installing from source, which
  504. is described in the next sections. The only requirement is to have
  505. GNU@tie{}tar and Xz.
  506. @c Note duplicated from the ``Installation'' node.
  507. @quotation Note
  508. We recommend the use of this
  509. @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
  510. shell installer script}. The script automates the download, installation, and
  511. initial configuration steps described below. It should be run as the root
  512. user. As root, you can thus run this:
  513. @example
  514. cd /tmp
  515. wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
  516. chmod +x guix-install.sh
  517. ./guix-install.sh
  518. @end example
  519. When you're done, @pxref{Application Setup} for extra configuration you
  520. might need, and @ref{Getting Started} for your first steps!
  521. @end quotation
  522. Installing goes along these lines:
  523. @enumerate
  524. @item
  525. @cindex downloading Guix binary
  526. Download the binary tarball from
  527. @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
  528. where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
  529. @code{i686} (32-bits) machine already running the kernel Linux, and so on
  530. (@pxref{GNU Distribution}).
  531. @c The following is somewhat duplicated in ``System Installation''.
  532. Make sure to download the associated @file{.sig} file and to verify the
  533. authenticity of the tarball against it, along these lines:
  534. @example
  535. $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
  536. $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
  537. @end example
  538. If that command fails because you do not have the required public key,
  539. then run this command to import it:
  540. @example
  541. $ wget @value{OPENPGP-SIGNING-KEY-URL} \
  542. -qO - | gpg --import -
  543. @end example
  544. @noindent
  545. and rerun the @code{gpg --verify} command.
  546. Take note that a warning like ``This key is not certified with a trusted
  547. signature!'' is normal.
  548. @c end authentication part
  549. @item
  550. Now, you need to become the @code{root} user. Depending on your distribution,
  551. you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
  552. @example
  553. # cd /tmp
  554. # tar --warning=no-timestamp -xf \
  555. /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
  556. # mv var/guix /var/ && mv gnu /
  557. @end example
  558. This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
  559. The latter contains a ready-to-use profile for @code{root} (see next
  560. step).
  561. Do @emph{not} unpack the tarball on a working Guix system since that
  562. would overwrite its own essential files.
  563. The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
  564. not emit warnings about ``implausibly old time stamps'' (such
  565. warnings were triggered by GNU@tie{}tar 1.26 and older; recent
  566. versions are fine).
  567. They stem from the fact that all the
  568. files in the archive have their modification time set to 1 (which
  569. means January 1st, 1970). This is done on purpose to make sure the
  570. archive content is independent of its creation time, thus making it
  571. reproducible.
  572. @item
  573. Make the profile available under @file{~root/.config/guix/current}, which is
  574. where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
  575. @example
  576. # mkdir -p ~root/.config/guix
  577. # ln -sf /var/guix/profiles/per-user/root/current-guix \
  578. ~root/.config/guix/current
  579. @end example
  580. Source @file{etc/profile} to augment @env{PATH} and other relevant
  581. environment variables:
  582. @example
  583. # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
  584. source $GUIX_PROFILE/etc/profile
  585. @end example
  586. @item
  587. Create the group and user accounts for build users as explained below
  588. (@pxref{Build Environment Setup}).
  589. @item
  590. Run the daemon, and set it to automatically start on boot.
  591. If your host distro uses the systemd init system, this can be achieved
  592. with these commands:
  593. @c Versions of systemd that supported symlinked service files are not
  594. @c yet widely deployed, so we should suggest that users copy the service
  595. @c files into place.
  596. @c
  597. @c See this thread for more information:
  598. @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
  599. @example
  600. # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
  601. ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
  602. /etc/systemd/system/
  603. # systemctl enable --now gnu-store.mount guix-daemon
  604. @end example
  605. If your host distro uses the Upstart init system:
  606. @example
  607. # initctl reload-configuration
  608. # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
  609. /etc/init/
  610. # start guix-daemon
  611. @end example
  612. Otherwise, you can still start the daemon manually with:
  613. @example
  614. # ~root/.config/guix/current/bin/guix-daemon \
  615. --build-users-group=guixbuild
  616. @end example
  617. @item
  618. Make the @command{guix} command available to other users on the machine,
  619. for instance with:
  620. @example
  621. # mkdir -p /usr/local/bin
  622. # cd /usr/local/bin
  623. # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
  624. @end example
  625. It is also a good idea to make the Info version of this manual available
  626. there:
  627. @example
  628. # mkdir -p /usr/local/share/info
  629. # cd /usr/local/share/info
  630. # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
  631. do ln -s $i ; done
  632. @end example
  633. That way, assuming @file{/usr/local/share/info} is in the search path,
  634. running @command{info guix} will open this manual (@pxref{Other Info
  635. Directories,,, texinfo, GNU Texinfo}, for more details on changing the
  636. Info search path).
  637. @item
  638. @cindex substitutes, authorization thereof
  639. To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
  640. (@pxref{Substitutes}), authorize them:
  641. @example
  642. # guix archive --authorize < \
  643. ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
  644. @end example
  645. @item
  646. Each user may need to perform a few additional steps to make their Guix
  647. environment ready for use, @pxref{Application Setup}.
  648. @end enumerate
  649. Voilà, the installation is complete!
  650. You can confirm that Guix is working by installing a sample package into
  651. the root profile:
  652. @example
  653. # guix install hello
  654. @end example
  655. The binary installation tarball can be (re)produced and verified simply
  656. by running the following command in the Guix source tree:
  657. @example
  658. make guix-binary.@var{system}.tar.xz
  659. @end example
  660. @noindent
  661. ...@: which, in turn, runs:
  662. @example
  663. guix pack -s @var{system} --localstatedir \
  664. --profile-name=current-guix guix
  665. @end example
  666. @xref{Invoking guix pack}, for more info on this handy tool.
  667. @node Requirements
  668. @section Requirements
  669. This section lists requirements when building Guix from source. The
  670. build procedure for Guix is the same as for other GNU software, and is
  671. not covered here. Please see the files @file{README} and @file{INSTALL}
  672. in the Guix source tree for additional details.
  673. @cindex official website
  674. GNU Guix is available for download from its website at
  675. @url{https://www.gnu.org/software/guix/}.
  676. GNU Guix depends on the following packages:
  677. @itemize
  678. @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
  679. 2.2.x;
  680. @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
  681. 0.1.0 or later;
  682. @item
  683. @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
  684. (@pxref{Guile Preparations, how to install the GnuTLS bindings for
  685. Guile,, gnutls-guile, GnuTLS-Guile});
  686. @item
  687. @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
  688. or later;
  689. @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib};
  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. When @url{http://www.bzip.org, libbz2} is available,
  717. @command{guix-daemon} can use it to compress build logs.
  718. @end itemize
  719. Unless @option{--disable-daemon} was passed to @command{configure}, the
  720. following packages are also needed:
  721. @itemize
  722. @item @url{https://gnupg.org/, GNU libgcrypt};
  723. @item @url{https://sqlite.org, SQLite 3};
  724. @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
  725. C++11 standard.
  726. @end itemize
  727. @cindex state directory
  728. When configuring Guix on a system that already has a Guix installation,
  729. be sure to specify the same state directory as the existing installation
  730. using the @option{--localstatedir} option of the @command{configure}
  731. script (@pxref{Directory Variables, @code{localstatedir},, standards,
  732. GNU Coding Standards}). Usually, this @var{localstatedir} option is
  733. set to the value @file{/var}. The @command{configure} script protects
  734. against unintended misconfiguration of @var{localstatedir} so you do not
  735. inadvertently corrupt your store (@pxref{The Store}).
  736. @node Running the Test Suite
  737. @section Running the Test Suite
  738. @cindex test suite
  739. After a successful @command{configure} and @code{make} run, it is a good
  740. idea to run the test suite. It can help catch issues with the setup or
  741. environment, or bugs in Guix itself---and really, reporting test
  742. failures is a good way to help improve the software. To run the test
  743. suite, type:
  744. @example
  745. make check
  746. @end example
  747. Test cases can run in parallel: you can use the @code{-j} option of
  748. GNU@tie{}make to speed things up. The first run may take a few minutes
  749. on a recent machine; subsequent runs will be faster because the store
  750. that is created for test purposes will already have various things in
  751. cache.
  752. It is also possible to run a subset of the tests by defining the
  753. @code{TESTS} makefile variable as in this example:
  754. @example
  755. make check TESTS="tests/store.scm tests/cpio.scm"
  756. @end example
  757. By default, tests results are displayed at a file level. In order to
  758. see the details of every individual test cases, it is possible to define
  759. the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
  760. @example
  761. make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
  762. @end example
  763. The underlying SRFI 64 custom Automake test driver used for the 'check'
  764. test suite (located at @file{build-aux/test-driver.scm}) also allows
  765. selecting which test cases to run at a finer level, via its
  766. @option{--select} and @option{--exclude} options. Here's an example, to
  767. run all the test cases from the @file{tests/packages.scm} test file
  768. whose names start with ``transaction-upgrade-entry'':
  769. @example
  770. export SCM_LOG_DRIVER_FLAGS="--select=^transaction-upgrade-entry"
  771. make check TESTS="tests/packages.scm"
  772. @end example
  773. Those wishing to inspect the results of failed tests directly from the
  774. command line can add the @option{--errors-only=yes} option to the
  775. @code{SCM_LOG_DRIVER_FLAGS} makefile variable and set the @code{VERBOSE}
  776. Automake makefile variable, as in:
  777. @example
  778. make check SCM_LOG_DRIVER_FLAGS="--brief=no --errors-only=yes" VERBOSE=1
  779. @end example
  780. The @option{--show-duration=yes} option can be used to print the
  781. duration of the individual test cases, when used in combination with
  782. @option{--brief=no}:
  783. @example
  784. make check SCM_LOG_DRIVER_FLAGS="--brief=no --show-duration=yes"
  785. @end example
  786. @xref{Parallel Test Harness,,,automake,GNU Automake} for more
  787. information about the Automake Parallel Test Harness.
  788. Upon failure, please email @email{bug-guix@@gnu.org} and attach the
  789. @file{test-suite.log} file. Please specify the Guix version being used
  790. as well as version numbers of the dependencies (@pxref{Requirements}) in
  791. your message.
  792. Guix also comes with a whole-system test suite that tests complete
  793. Guix System instances. It can only run on systems where
  794. Guix is already installed, using:
  795. @example
  796. make check-system
  797. @end example
  798. @noindent
  799. or, again, by defining @code{TESTS} to select a subset of tests to run:
  800. @example
  801. make check-system TESTS="basic mcron"
  802. @end example
  803. These system tests are defined in the @code{(gnu tests @dots{})}
  804. modules. They work by running the operating systems under test with
  805. lightweight instrumentation in a virtual machine (VM). They can be
  806. computationally intensive or rather cheap, depending on whether
  807. substitutes are available for their dependencies (@pxref{Substitutes}).
  808. Some of them require a lot of storage space to hold VM images.
  809. Again in case of test failures, please send @email{bug-guix@@gnu.org}
  810. all the details.
  811. @node Setting Up the Daemon
  812. @section Setting Up the Daemon
  813. @cindex daemon
  814. Operations such as building a package or running the garbage collector
  815. are all performed by a specialized process, the @dfn{build daemon}, on
  816. behalf of clients. Only the daemon may access the store and its
  817. associated database. Thus, any operation that manipulates the store
  818. goes through the daemon. For instance, command-line tools such as
  819. @command{guix package} and @command{guix build} communicate with the
  820. daemon (@i{via} remote procedure calls) to instruct it what to do.
  821. The following sections explain how to prepare the build daemon's
  822. environment. See also @ref{Substitutes}, for information on how to allow
  823. the daemon to download pre-built binaries.
  824. @menu
  825. * Build Environment Setup:: Preparing the isolated build environment.
  826. * Daemon Offload Setup:: Offloading builds to remote machines.
  827. * SELinux Support:: Using an SELinux policy for the daemon.
  828. @end menu
  829. @node Build Environment Setup
  830. @subsection Build Environment Setup
  831. @cindex build environment
  832. In a standard multi-user setup, Guix and its daemon---the
  833. @command{guix-daemon} program---are installed by the system
  834. administrator; @file{/gnu/store} is owned by @code{root} and
  835. @command{guix-daemon} runs as @code{root}. Unprivileged users may use
  836. Guix tools to build packages or otherwise access the store, and the
  837. daemon will do it on their behalf, ensuring that the store is kept in a
  838. consistent state, and allowing built packages to be shared among users.
  839. @cindex build users
  840. When @command{guix-daemon} runs as @code{root}, you may not want package
  841. build processes themselves to run as @code{root} too, for obvious
  842. security reasons. To avoid that, a special pool of @dfn{build users}
  843. should be created for use by build processes started by the daemon.
  844. These build users need not have a shell and a home directory: they will
  845. just be used when the daemon drops @code{root} privileges in build
  846. processes. Having several such users allows the daemon to launch
  847. distinct build processes under separate UIDs, which guarantees that they
  848. do not interfere with each other---an essential feature since builds are
  849. regarded as pure functions (@pxref{Introduction}).
  850. On a GNU/Linux system, a build user pool may be created like this (using
  851. Bash syntax and the @code{shadow} commands):
  852. @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
  853. @c for why `-G' is needed.
  854. @example
  855. # groupadd --system guixbuild
  856. # for i in `seq -w 1 10`;
  857. do
  858. useradd -g guixbuild -G guixbuild \
  859. -d /var/empty -s `which nologin` \
  860. -c "Guix build user $i" --system \
  861. guixbuilder$i;
  862. done
  863. @end example
  864. @noindent
  865. The number of build users determines how many build jobs may run in
  866. parallel, as specified by the @option{--max-jobs} option
  867. (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
  868. @command{guix system vm} and related commands, you may need to add the
  869. build users to the @code{kvm} group so they can access @file{/dev/kvm},
  870. using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
  871. (@pxref{Invoking guix system}).
  872. The @code{guix-daemon} program may then be run as @code{root} with the
  873. following command@footnote{If your machine uses the systemd init system,
  874. dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
  875. file in @file{/etc/systemd/system} will ensure that
  876. @command{guix-daemon} is automatically started. Similarly, if your
  877. machine uses the Upstart init system, drop the
  878. @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
  879. file in @file{/etc/init}.}:
  880. @example
  881. # guix-daemon --build-users-group=guixbuild
  882. @end example
  883. @cindex chroot
  884. @noindent
  885. This way, the daemon starts build processes in a chroot, under one of
  886. the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
  887. environment contains nothing but:
  888. @c Keep this list in sync with libstore/build.cc! -----------------------
  889. @itemize
  890. @item
  891. a minimal @code{/dev} directory, created mostly independently from the
  892. host @code{/dev}@footnote{``Mostly'', because while the set of files
  893. that appear in the chroot's @code{/dev} is fixed, most of these files
  894. can only be created if the host has them.};
  895. @item
  896. the @code{/proc} directory; it only shows the processes of the container
  897. since a separate PID name space is used;
  898. @item
  899. @file{/etc/passwd} with an entry for the current user and an entry for
  900. user @file{nobody};
  901. @item
  902. @file{/etc/group} with an entry for the user's group;
  903. @item
  904. @file{/etc/hosts} with an entry that maps @code{localhost} to
  905. @code{127.0.0.1};
  906. @item
  907. a writable @file{/tmp} directory.
  908. @end itemize
  909. You can influence the directory where the daemon stores build trees
  910. @i{via} the @env{TMPDIR} environment variable. However, the build tree
  911. within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
  912. where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
  913. This way, the value of @env{TMPDIR} does not leak inside build
  914. environments, which avoids discrepancies in cases where build processes
  915. capture the name of their build tree.
  916. @vindex http_proxy
  917. @vindex https_proxy
  918. The daemon also honors the @env{http_proxy} and @env{https_proxy}
  919. environment variables for HTTP and HTTPS downloads it performs, be it
  920. for fixed-output derivations (@pxref{Derivations}) or for substitutes
  921. (@pxref{Substitutes}).
  922. If you are installing Guix as an unprivileged user, it is still possible
  923. to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
  924. However, build processes will not be isolated from one another, and not
  925. from the rest of the system. Thus, build processes may interfere with
  926. each other, and may access programs, libraries, and other files
  927. available on the system---making it much harder to view them as
  928. @emph{pure} functions.
  929. @node Daemon Offload Setup
  930. @subsection Using the Offload Facility
  931. @cindex offloading
  932. @cindex build hook
  933. When desired, the build daemon can @dfn{offload} derivation builds to
  934. other machines running Guix, using the @code{offload} @dfn{build
  935. hook}@footnote{This feature is available only when
  936. @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
  937. present.}. When that feature is enabled, a list of user-specified build
  938. machines is read from @file{/etc/guix/machines.scm}; every time a build
  939. is requested, for instance via @code{guix build}, the daemon attempts to
  940. offload it to one of the machines that satisfy the constraints of the
  941. derivation, in particular its system types---e.g., @code{x86_64-linux}.
  942. A single machine can have multiple system types, either because its
  943. architecture natively supports it, via emulation
  944. (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
  945. or both. Missing prerequisites for the build are
  946. copied over SSH to the target machine, which then proceeds with the
  947. build; upon success the output(s) of the build are copied back to the
  948. initial machine. The offload facility comes with a basic scheduler that
  949. attempts to select the best machine. The best machine is chosen among
  950. the available machines based on criteria such as:
  951. @enumerate
  952. @item
  953. The availability of a build slot. A build machine can have as many
  954. build slots (connections) as the value of the @code{parallel-builds}
  955. field of its @code{build-machine} object.
  956. @item
  957. Its relative speed, as defined via the @code{speed} field of its
  958. @code{build-machine} object.
  959. @item
  960. Its load. The normalized machine load must be lower than a threshold
  961. value, configurable via the @code{overload-threshold} field of its
  962. @code{build-machine} object.
  963. @item
  964. Disk space availability. More than a 100 MiB must be available.
  965. @end enumerate
  966. The @file{/etc/guix/machines.scm} file typically looks like this:
  967. @lisp
  968. (list (build-machine
  969. (name "eightysix.example.org")
  970. (systems (list "x86_64-linux" "i686-linux"))
  971. (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
  972. (user "bob")
  973. (speed 2.)) ;incredibly fast!
  974. (build-machine
  975. (name "armeight.example.org")
  976. (systems (list "aarch64-linux"))
  977. (host-key "ssh-rsa AAAAB3Nza@dots{}")
  978. (user "alice")
  979. (private-key
  980. (string-append (getenv "HOME")
  981. "/.ssh/identity-for-guix"))))
  982. @end lisp
  983. @noindent
  984. In the example above we specify a list of two build machines, one for
  985. the @code{x86_64} and @code{i686} architectures and one for the
  986. @code{aarch64} architecture.
  987. In fact, this file is---not surprisingly!---a Scheme file that is
  988. evaluated when the @code{offload} hook is started. Its return value
  989. must be a list of @code{build-machine} objects. While this example
  990. shows a fixed list of build machines, one could imagine, say, using
  991. DNS-SD to return a list of potential build machines discovered in the
  992. local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
  993. Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
  994. detailed below.
  995. @deftp {Data Type} build-machine
  996. This data type represents build machines to which the daemon may offload
  997. builds. The important fields are:
  998. @table @code
  999. @item name
  1000. The host name of the remote machine.
  1001. @item systems
  1002. The system types the remote machine supports---e.g., @code{(list
  1003. "x86_64-linux" "i686-linux")}.
  1004. @item user
  1005. The user account to use when connecting to the remote machine over SSH.
  1006. Note that the SSH key pair must @emph{not} be passphrase-protected, to
  1007. allow non-interactive logins.
  1008. @item host-key
  1009. This must be the machine's SSH @dfn{public host key} in OpenSSH format.
  1010. This is used to authenticate the machine when we connect to it. It is a
  1011. long string that looks like this:
  1012. @example
  1013. ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
  1014. @end example
  1015. If the machine is running the OpenSSH daemon, @command{sshd}, the host
  1016. key can be found in a file such as
  1017. @file{/etc/ssh/ssh_host_ed25519_key.pub}.
  1018. If the machine is running the SSH daemon of GNU@tie{}lsh,
  1019. @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
  1020. similar file. It can be converted to the OpenSSH format using
  1021. @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
  1022. @example
  1023. $ lsh-export-key --openssh < /etc/lsh/host-key.pub
  1024. ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
  1025. @end example
  1026. @end table
  1027. A number of optional fields may be specified:
  1028. @table @asis
  1029. @item @code{port} (default: @code{22})
  1030. Port number of SSH server on the machine.
  1031. @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
  1032. The SSH private key file to use when connecting to the machine, in
  1033. OpenSSH format. This key must not be protected with a passphrase.
  1034. Note that the default value is the private key @emph{of the root
  1035. account}. Make sure it exists if you use the default.
  1036. @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
  1037. @itemx @code{compression-level} (default: @code{3})
  1038. The SSH-level compression methods and compression level requested.
  1039. Note that offloading relies on SSH compression to reduce bandwidth usage
  1040. when transferring files to and from build machines.
  1041. @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
  1042. File name of the Unix-domain socket @command{guix-daemon} is listening
  1043. to on that machine.
  1044. @item @code{overload-threshold} (default: @code{0.6})
  1045. The load threshold above which a potential offload machine is
  1046. disregarded by the offload scheduler. The value roughly translates to
  1047. the total processor usage of the build machine, ranging from 0.0 (0%) to
  1048. 1.0 (100%). It can also be disabled by setting
  1049. @code{overload-threshold} to @code{#f}.
  1050. @item @code{parallel-builds} (default: @code{1})
  1051. The number of builds that may run in parallel on the machine.
  1052. @item @code{speed} (default: @code{1.0})
  1053. A ``relative speed factor''. The offload scheduler will tend to prefer
  1054. machines with a higher speed factor.
  1055. @item @code{features} (default: @code{'()})
  1056. A list of strings denoting specific features supported by the machine.
  1057. An example is @code{"kvm"} for machines that have the KVM Linux modules
  1058. and corresponding hardware support. Derivations can request features by
  1059. name, and they will be scheduled on matching build machines.
  1060. @end table
  1061. @end deftp
  1062. The @command{guix} command must be in the search path on the build
  1063. machines. You can check whether this is the case by running:
  1064. @example
  1065. ssh build-machine guix repl --version
  1066. @end example
  1067. There is one last thing to do once @file{machines.scm} is in place. As
  1068. explained above, when offloading, files are transferred back and forth
  1069. between the machine stores. For this to work, you first need to
  1070. generate a key pair on each machine to allow the daemon to export signed
  1071. archives of files from the store (@pxref{Invoking guix archive}):
  1072. @example
  1073. # guix archive --generate-key
  1074. @end example
  1075. @noindent
  1076. Each build machine must authorize the key of the master machine so that
  1077. it accepts store items it receives from the master:
  1078. @example
  1079. # guix archive --authorize < master-public-key.txt
  1080. @end example
  1081. @noindent
  1082. Likewise, the master machine must authorize the key of each build machine.
  1083. All the fuss with keys is here to express pairwise mutual trust
  1084. relations between the master and the build machines. Concretely, when
  1085. the master receives files from a build machine (and @i{vice versa}), its
  1086. build daemon can make sure they are genuine, have not been tampered
  1087. with, and that they are signed by an authorized key.
  1088. @cindex offload test
  1089. To test whether your setup is operational, run this command on the
  1090. master node:
  1091. @example
  1092. # guix offload test
  1093. @end example
  1094. This will attempt to connect to each of the build machines specified in
  1095. @file{/etc/guix/machines.scm}, make sure Guix is
  1096. available on each machine, attempt to export to the machine and import
  1097. from it, and report any error in the process.
  1098. If you want to test a different machine file, just specify it on the
  1099. command line:
  1100. @example
  1101. # guix offload test machines-qualif.scm
  1102. @end example
  1103. Last, you can test the subset of the machines whose name matches a
  1104. regular expression like this:
  1105. @example
  1106. # guix offload test machines.scm '\.gnu\.org$'
  1107. @end example
  1108. @cindex offload status
  1109. To display the current load of all build hosts, run this command on the
  1110. main node:
  1111. @example
  1112. # guix offload status
  1113. @end example
  1114. @node SELinux Support
  1115. @subsection SELinux Support
  1116. @cindex SELinux, daemon policy
  1117. @cindex mandatory access control, SELinux
  1118. @cindex security, guix-daemon
  1119. Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
  1120. can be installed on a system where SELinux is enabled, in order to label
  1121. Guix files and to specify the expected behavior of the daemon. Since
  1122. Guix System does not provide an SELinux base policy, the daemon policy cannot
  1123. be used on Guix System.
  1124. @subsubsection Installing the SELinux policy
  1125. @cindex SELinux, policy installation
  1126. To install the policy run this command as root:
  1127. @example
  1128. semodule -i etc/guix-daemon.cil
  1129. @end example
  1130. Then relabel the file system with @code{restorecon} or by a different
  1131. mechanism provided by your system.
  1132. Once the policy is installed, the file system has been relabeled, and
  1133. the daemon has been restarted, it should be running in the
  1134. @code{guix_daemon_t} context. You can confirm this with the following
  1135. command:
  1136. @example
  1137. ps -Zax | grep guix-daemon
  1138. @end example
  1139. Monitor the SELinux log files as you run a command like @code{guix build
  1140. hello} to convince yourself that SELinux permits all necessary
  1141. operations.
  1142. @subsubsection Limitations
  1143. @cindex SELinux, limitations
  1144. This policy is not perfect. Here is a list of limitations or quirks
  1145. that should be considered when deploying the provided SELinux policy for
  1146. the Guix daemon.
  1147. @enumerate
  1148. @item
  1149. @code{guix_daemon_socket_t} isn’t actually used. None of the socket
  1150. operations involve contexts that have anything to do with
  1151. @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
  1152. but it would be preferrable to define socket rules for only this label.
  1153. @item
  1154. @code{guix gc} cannot access arbitrary links to profiles. By design,
  1155. the file label of the destination of a symlink is independent of the
  1156. file label of the link itself. Although all profiles under
  1157. $localstatedir are labelled, the links to these profiles inherit the
  1158. label of the directory they are in. For links in the user’s home
  1159. directory this will be @code{user_home_t}. But for links from the root
  1160. user’s home directory, or @file{/tmp}, or the HTTP server’s working
  1161. directory, etc, this won’t work. @code{guix gc} would be prevented from
  1162. reading and following these links.
  1163. @item
  1164. The daemon’s feature to listen for TCP connections might no longer work.
  1165. This might require extra rules, because SELinux treats network sockets
  1166. differently from files.
  1167. @item
  1168. Currently all files with a name matching the regular expression
  1169. @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
  1170. label @code{guix_daemon_exec_t}; this means that @emph{any} file with
  1171. that name in any profile would be permitted to run in the
  1172. @code{guix_daemon_t} domain. This is not ideal. An attacker could
  1173. build a package that provides this executable and convince a user to
  1174. install and run it, which lifts it into the @code{guix_daemon_t} domain.
  1175. At that point SELinux could not prevent it from accessing files that are
  1176. allowed for processes in that domain.
  1177. You will need to relabel the store directory after all upgrades to
  1178. @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
  1179. store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
  1180. or by other means provided by your operating system.
  1181. We could generate a much more restrictive policy at installation time,
  1182. so that only the @emph{exact} file name of the currently installed
  1183. @code{guix-daemon} executable would be labelled with
  1184. @code{guix_daemon_exec_t}, instead of using a broad regular expression.
  1185. The downside is that root would have to install or upgrade the policy at
  1186. installation time whenever the Guix package that provides the
  1187. effectively running @code{guix-daemon} executable is upgraded.
  1188. @end enumerate
  1189. @node Invoking guix-daemon
  1190. @section Invoking @command{guix-daemon}
  1191. The @command{guix-daemon} program implements all the functionality to
  1192. access the store. This includes launching build processes, running the
  1193. garbage collector, querying the availability of a build result, etc. It
  1194. is normally run as @code{root} like this:
  1195. @example
  1196. # guix-daemon --build-users-group=guixbuild
  1197. @end example
  1198. @noindent
  1199. For details on how to set it up, @pxref{Setting Up the Daemon}.
  1200. @cindex chroot
  1201. @cindex container, build environment
  1202. @cindex build environment
  1203. @cindex reproducible builds
  1204. By default, @command{guix-daemon} launches build processes under
  1205. different UIDs, taken from the build group specified with
  1206. @option{--build-users-group}. In addition, each build process is run in a
  1207. chroot environment that only contains the subset of the store that the
  1208. build process depends on, as specified by its derivation
  1209. (@pxref{Programming Interface, derivation}), plus a set of specific
  1210. system directories. By default, the latter contains @file{/dev} and
  1211. @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
  1212. @dfn{container}: in addition to having its own file system tree, it has
  1213. a separate mount name space, its own PID name space, network name space,
  1214. etc. This helps achieve reproducible builds (@pxref{Features}).
  1215. When the daemon performs a build on behalf of the user, it creates a
  1216. build directory under @file{/tmp} or under the directory specified by
  1217. its @env{TMPDIR} environment variable. This directory is shared with
  1218. the container for the duration of the build, though within the container,
  1219. the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
  1220. The build directory is automatically deleted upon completion, unless the
  1221. build failed and the client specified @option{--keep-failed}
  1222. (@pxref{Invoking guix build, @option{--keep-failed}}).
  1223. The daemon listens for connections and spawns one sub-process for each session
  1224. started by a client (one of the @command{guix} sub-commands). The
  1225. @command{guix processes} command allows you to get an overview of the activity
  1226. on your system by viewing each of the active sessions and clients.
  1227. @xref{Invoking guix processes}, for more information.
  1228. The following command-line options are supported:
  1229. @table @code
  1230. @item --build-users-group=@var{group}
  1231. Take users from @var{group} to run build processes (@pxref{Setting Up
  1232. the Daemon, build users}).
  1233. @item --no-substitutes
  1234. @cindex substitutes
  1235. Do not use substitutes for build products. That is, always build things
  1236. locally instead of allowing downloads of pre-built binaries
  1237. (@pxref{Substitutes}).
  1238. When the daemon runs with @option{--no-substitutes}, clients can still
  1239. explicitly enable substitution @i{via} the @code{set-build-options}
  1240. remote procedure call (@pxref{The Store}).
  1241. @anchor{daemon-substitute-urls}
  1242. @item --substitute-urls=@var{urls}
  1243. Consider @var{urls} the default whitespace-separated list of substitute
  1244. source URLs. When this option is omitted,
  1245. @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
  1246. This means that substitutes may be downloaded from @var{urls}, as long
  1247. as they are signed by a trusted signature (@pxref{Substitutes}).
  1248. @xref{Getting Substitutes from Other Servers}, for more information on
  1249. how to configure the daemon to get substitutes from other servers.
  1250. @item --substitute-methods=@var{methods}
  1251. Consider @var{methods} the whitespace-separated list of substitution
  1252. methods (‘substituters’) to use. When this option is omitted, @code{http}
  1253. is used. The @code{http} substituter supports both the HTTP and HTTPS
  1254. protocol.
  1255. @xref{Defining Substituters} for information on how to define new
  1256. substituters, and @pxref{Getting Substitutes from Other Protocols}
  1257. on how to use non-HTTP and non-HTTPS substituters.
  1258. @c TODO: see <section> for information on how to configure the
  1259. @c IPFS and GNUnet substituters
  1260. @cindex offloading
  1261. @item --no-offload
  1262. Do not use offload builds to other machines (@pxref{Daemon Offload
  1263. Setup}). That is, always build things locally instead of offloading
  1264. builds to remote machines.
  1265. @item --cache-failures
  1266. Cache build failures. By default, only successful builds are cached.
  1267. When this option is used, @command{guix gc --list-failures} can be used
  1268. to query the set of store items marked as failed; @command{guix gc
  1269. --clear-failures} removes store items from the set of cached failures.
  1270. @xref{Invoking guix gc}.
  1271. @item --cores=@var{n}
  1272. @itemx -c @var{n}
  1273. Use @var{n} CPU cores to build each derivation; @code{0} means as many
  1274. as available.
  1275. The default value is @code{0}, but it may be overridden by clients, such
  1276. as the @option{--cores} option of @command{guix build} (@pxref{Invoking
  1277. guix build}).
  1278. The effect is to define the @env{NIX_BUILD_CORES} environment variable
  1279. in the build process, which can then use it to exploit internal
  1280. parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
  1281. @item --max-jobs=@var{n}
  1282. @itemx -M @var{n}
  1283. Allow at most @var{n} build jobs in parallel. The default value is
  1284. @code{1}. Setting it to @code{0} means that no builds will be performed
  1285. locally; instead, the daemon will offload builds (@pxref{Daemon Offload
  1286. Setup}), or simply fail.
  1287. @item --max-silent-time=@var{seconds}
  1288. When the build or substitution process remains silent 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{--max-silent-time}}).
  1293. @item --timeout=@var{seconds}
  1294. Likewise, when the build or substitution process lasts for more than
  1295. @var{seconds}, terminate it and report a build failure.
  1296. The default value is @code{0}, which disables the timeout.
  1297. The value specified here can be overridden by clients (@pxref{Common
  1298. Build Options, @option{--timeout}}).
  1299. @item --rounds=@var{N}
  1300. Build each derivation @var{n} times in a row, and raise an error if
  1301. consecutive build results are not bit-for-bit identical. Note that this
  1302. setting can be overridden by clients such as @command{guix build}
  1303. (@pxref{Invoking guix build}).
  1304. When used in conjunction with @option{--keep-failed}, the differing
  1305. output is kept in the store, under @file{/gnu/store/@dots{}-check}.
  1306. This makes it easy to look for differences between the two results.
  1307. @item --debug
  1308. Produce debugging output.
  1309. This is useful to debug daemon start-up issues, but then it may be
  1310. overridden by clients, for example the @option{--verbosity} option of
  1311. @command{guix build} (@pxref{Invoking guix build}).
  1312. @item --chroot-directory=@var{dir}
  1313. Add @var{dir} to the build chroot.
  1314. Doing this may change the result of build processes---for instance if
  1315. they use optional dependencies found in @var{dir} when it is available,
  1316. and not otherwise. For that reason, it is not recommended to do so.
  1317. Instead, make sure that each derivation declares all the inputs that it
  1318. needs.
  1319. @item --disable-chroot
  1320. Disable chroot builds.
  1321. Using this option is not recommended since, again, it would allow build
  1322. processes to gain access to undeclared dependencies. It is necessary,
  1323. though, when @command{guix-daemon} is running under an unprivileged user
  1324. account.
  1325. @item --log-compression=@var{type}
  1326. Compress build logs according to @var{type}, one of @code{gzip},
  1327. @code{bzip2}, or @code{none}.
  1328. Unless @option{--lose-logs} is used, all the build logs are kept in the
  1329. @var{localstatedir}. To save space, the daemon automatically compresses
  1330. them with Bzip2 by default.
  1331. @item --discover[=yes|no]
  1332. Whether to discover substitute servers on the local network using mDNS
  1333. and DNS-SD.
  1334. This feature is still experimental. However, here are a few
  1335. considerations.
  1336. @enumerate
  1337. @item
  1338. It might be faster/less expensive than fetching from remote servers;
  1339. @item
  1340. There are no security risks, only genuine substitutes will be used
  1341. (@pxref{Substitute Authentication});
  1342. @item
  1343. An attacker advertising @command{guix publish} on your LAN cannot serve
  1344. you malicious binaries, but they can learn what software you’re
  1345. installing;
  1346. @item
  1347. Servers may serve substitute over HTTP, unencrypted, so anyone on the
  1348. LAN can see what software you’re installing.
  1349. @end enumerate
  1350. It is also possible to enable or disable substitute server discovery at
  1351. run-time by running:
  1352. @example
  1353. herd discover guix-daemon on
  1354. herd discover guix-daemon off
  1355. @end example
  1356. @item --disable-deduplication
  1357. @cindex deduplication
  1358. Disable automatic file ``deduplication'' in the store.
  1359. By default, files added to the store are automatically ``deduplicated'':
  1360. if a newly added file is identical to another one found in the store,
  1361. the daemon makes the new file a hard link to the other file. This can
  1362. noticeably reduce disk usage, at the expense of slightly increased
  1363. input/output load at the end of a build process. This option disables
  1364. this optimization.
  1365. @item --gc-keep-outputs[=yes|no]
  1366. Tell whether the garbage collector (GC) must keep outputs of live
  1367. derivations.
  1368. @cindex GC roots
  1369. @cindex garbage collector roots
  1370. When set to @code{yes}, the GC will keep the outputs of any live
  1371. derivation available in the store---the @file{.drv} files. The default
  1372. is @code{no}, meaning that derivation outputs are kept only if they are
  1373. reachable from a GC root. @xref{Invoking guix gc}, for more on GC
  1374. roots.
  1375. @item --gc-keep-derivations[=yes|no]
  1376. Tell whether the garbage collector (GC) must keep derivations
  1377. corresponding to live outputs.
  1378. When set to @code{yes}, as is the case by default, the GC keeps
  1379. derivations---i.e., @file{.drv} files---as long as at least one of their
  1380. outputs is live. This allows users to keep track of the origins of
  1381. items in their store. Setting it to @code{no} saves a bit of disk
  1382. space.
  1383. In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
  1384. liveness to flow from outputs to derivations, and setting
  1385. @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
  1386. derivations to outputs. When both are set to @code{yes}, the effect is
  1387. to keep all the build prerequisites (the sources, compiler, libraries,
  1388. and other build-time tools) of live objects in the store, regardless of
  1389. whether these prerequisites are reachable from a GC root. This is
  1390. convenient for developers since it saves rebuilds or downloads.
  1391. @item --impersonate-linux-2.6
  1392. On Linux-based systems, impersonate Linux 2.6. This means that the
  1393. kernel's @command{uname} system call will report 2.6 as the release number.
  1394. This might be helpful to build programs that (usually wrongfully) depend
  1395. on the kernel version number.
  1396. @item --lose-logs
  1397. Do not keep build logs. By default they are kept under
  1398. @file{@var{localstatedir}/guix/log}.
  1399. @item --system=@var{system}
  1400. Assume @var{system} as the current system type. By default it is the
  1401. architecture/kernel pair found at configure time, such as
  1402. @code{x86_64-linux}.
  1403. @item --listen=@var{endpoint}
  1404. Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
  1405. as the file name of a Unix-domain socket if it starts with
  1406. @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
  1407. host name or host name and port to listen to. Here are a few examples:
  1408. @table @code
  1409. @item --listen=/gnu/var/daemon
  1410. Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
  1411. creating it if needed.
  1412. @item --listen=localhost
  1413. @cindex daemon, remote access
  1414. @cindex remote access to the daemon
  1415. @cindex daemon, cluster setup
  1416. @cindex clusters, daemon setup
  1417. Listen for TCP connections on the network interface corresponding to
  1418. @code{localhost}, on port 44146.
  1419. @item --listen=128.0.0.42:1234
  1420. Listen for TCP connections on the network interface corresponding to
  1421. @code{128.0.0.42}, on port 1234.
  1422. @end table
  1423. This option can be repeated multiple times, in which case
  1424. @command{guix-daemon} accepts connections on all the specified
  1425. endpoints. Users can tell client commands what endpoint to connect to
  1426. by setting the @env{GUIX_DAEMON_SOCKET} environment variable
  1427. (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
  1428. @quotation Note
  1429. The daemon protocol is @emph{unauthenticated and unencrypted}. Using
  1430. @option{--listen=@var{host}} is suitable on local networks, such as
  1431. clusters, where only trusted nodes may connect to the build daemon. In
  1432. other cases where remote access to the daemon is needed, we recommend
  1433. using Unix-domain sockets along with SSH.
  1434. @end quotation
  1435. When @option{--listen} is omitted, @command{guix-daemon} listens for
  1436. connections on the Unix-domain socket located at
  1437. @file{@var{localstatedir}/guix/daemon-socket/socket}.
  1438. @end table
  1439. @node Application Setup
  1440. @section Application Setup
  1441. @cindex foreign distro
  1442. When using Guix on top of GNU/Linux distribution other than Guix System---a
  1443. so-called @dfn{foreign distro}---a few additional steps are needed to
  1444. get everything in place. Here are some of them.
  1445. @subsection Locales
  1446. @anchor{locales-and-locpath}
  1447. @cindex locales, when not on Guix System
  1448. @vindex LOCPATH
  1449. @vindex GUIX_LOCPATH
  1450. Packages installed @i{via} Guix will not use the locale data of the
  1451. host system. Instead, you must first install one of the locale packages
  1452. available with Guix and then define the @env{GUIX_LOCPATH} environment
  1453. variable:
  1454. @example
  1455. $ guix install glibc-locales
  1456. $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
  1457. @end example
  1458. Note that the @code{glibc-locales} package contains data for all the
  1459. locales supported by the GNU@tie{}libc and weighs in at around
  1460. 917@tie{}MiB@. Alternatively, the @code{glibc-utf8-locales} is smaller but
  1461. limited to a few UTF-8 locales.
  1462. The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
  1463. (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
  1464. Manual}). There are two important differences though:
  1465. @enumerate
  1466. @item
  1467. @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
  1468. provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
  1469. to make sure the programs of the foreign distro will not end up loading
  1470. incompatible locale data.
  1471. @item
  1472. libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
  1473. @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
  1474. should your Guix profile contain a mixture of programs linked against
  1475. different libc version, each libc version will only try to load locale
  1476. data in the right format.
  1477. @end enumerate
  1478. This is important because the locale data format used by different libc
  1479. versions may be incompatible.
  1480. @subsection Name Service Switch
  1481. @cindex name service switch, glibc
  1482. @cindex NSS (name service switch), glibc
  1483. @cindex nscd (name service caching daemon)
  1484. @cindex name service caching daemon (nscd)
  1485. When using Guix on a foreign distro, we @emph{strongly recommend} that
  1486. the system run the GNU C library's @dfn{name service cache daemon},
  1487. @command{nscd}, which should be listening on the
  1488. @file{/var/run/nscd/socket} socket. Failing to do that, applications
  1489. installed with Guix may fail to look up host names or user accounts, or
  1490. may even crash. The next paragraphs explain why.
  1491. @cindex @file{nsswitch.conf}
  1492. The GNU C library implements a @dfn{name service switch} (NSS), which is
  1493. an extensible mechanism for ``name lookups'' in general: host name
  1494. resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
  1495. The GNU C Library Reference Manual}).
  1496. @cindex Network information service (NIS)
  1497. @cindex NIS (Network information service)
  1498. Being extensible, the NSS supports @dfn{plugins}, which provide new name
  1499. lookup implementations: for example, the @code{nss-mdns} plugin allow
  1500. resolution of @code{.local} host names, the @code{nis} plugin allows
  1501. user account lookup using the Network information service (NIS), and so
  1502. on. These extra ``lookup services'' are configured system-wide in
  1503. @file{/etc/nsswitch.conf}, and all the programs running on the system
  1504. honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
  1505. Reference Manual}).
  1506. When they perform a name lookup---for instance by calling the
  1507. @code{getaddrinfo} function in C---applications first try to connect to
  1508. the nscd; on success, nscd performs name lookups on their behalf. If
  1509. the nscd is not running, then they perform the name lookup by
  1510. themselves, by loading the name lookup services into their own address
  1511. space and running it. These name lookup services---the
  1512. @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
  1513. the host system's C library, rather than from the C library the
  1514. application is linked against (the C library coming from Guix).
  1515. And this is where the problem is: if your application is linked against
  1516. Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
  1517. another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
  1518. likely crash or have its name lookups fail unexpectedly.
  1519. Running @command{nscd} on the system, among other advantages, eliminates
  1520. this binary incompatibility problem because those @code{libnss_*.so}
  1521. files are loaded in the @command{nscd} process, not in applications
  1522. themselves.
  1523. @subsection X11 Fonts
  1524. @cindex fonts
  1525. The majority of graphical applications use Fontconfig to locate and
  1526. load fonts and perform X11-client-side rendering. The @code{fontconfig}
  1527. package in Guix looks for fonts in @file{$HOME/.guix-profile}
  1528. by default. Thus, to allow graphical applications installed with Guix
  1529. to display fonts, you have to install fonts with Guix as well.
  1530. Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
  1531. @code{font-gnu-freefont}.
  1532. @cindex @code{fc-cache}
  1533. @cindex font cache
  1534. Once you have installed or removed fonts, or when you notice an
  1535. application that does not find fonts, you may need to install Fontconfig
  1536. and to force an update of its font cache by running:
  1537. @example
  1538. guix install fontconfig
  1539. fc-cache -rv
  1540. @end example
  1541. To display text written in Chinese languages, Japanese, or Korean in
  1542. graphical applications, consider installing
  1543. @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
  1544. has multiple outputs, one per language family (@pxref{Packages with
  1545. Multiple Outputs}). For instance, the following command installs fonts
  1546. for Chinese languages:
  1547. @example
  1548. guix install font-adobe-source-han-sans:cn
  1549. @end example
  1550. @cindex @code{xterm}
  1551. Older programs such as @command{xterm} do not use Fontconfig and instead
  1552. rely on server-side font rendering. Such programs require to specify a
  1553. full name of a font using XLFD (X Logical Font Description), like this:
  1554. @example
  1555. -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
  1556. @end example
  1557. To be able to use such full names for the TrueType fonts installed in
  1558. your Guix profile, you need to extend the font path of the X server:
  1559. @c Note: 'xset' does not accept symlinks so the trick below arranges to
  1560. @c get at the real directory. See <https://bugs.gnu.org/30655>.
  1561. @example
  1562. xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
  1563. @end example
  1564. @cindex @code{xlsfonts}
  1565. After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
  1566. to make sure your TrueType fonts are listed there.
  1567. @subsection X.509 Certificates
  1568. @cindex @code{nss-certs}
  1569. The @code{nss-certs} package provides X.509 certificates, which allow
  1570. programs to authenticate Web servers accessed over HTTPS.
  1571. When using Guix on a foreign distro, you can install this package and
  1572. define the relevant environment variables so that packages know where to
  1573. look for certificates. @xref{X.509 Certificates}, for detailed
  1574. information.
  1575. @subsection Emacs Packages
  1576. @cindex @code{emacs}
  1577. When you install Emacs packages with Guix, the Elisp files are placed
  1578. under the @file{share/emacs/site-lisp/} directory of the profile in
  1579. which they are installed. The Elisp libraries are made available to
  1580. Emacs through the @env{EMACSLOADPATH} environment variable, which is
  1581. set when installing Emacs itself.
  1582. Additionally, autoload definitions are automatically evaluated at the
  1583. initialization of Emacs, by the Guix-specific
  1584. @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
  1585. want to avoid auto-loading the Emacs packages installed with Guix, you
  1586. can do so by running Emacs with the @option{--no-site-file} option
  1587. (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
  1588. @node Upgrading Guix
  1589. @section Upgrading Guix
  1590. @cindex Upgrading Guix, on a foreign distro
  1591. To upgrade Guix, run:
  1592. @example
  1593. guix pull
  1594. @end example
  1595. @xref{Invoking guix pull}, for more information.
  1596. @cindex upgrading Guix for the root user, on a foreign distro
  1597. @cindex upgrading the Guix daemon, on a foreign distro
  1598. @cindex @command{guix pull} for the root user, on a foreign distro
  1599. On a foreign distro, you can upgrade the build daemon by running:
  1600. @example
  1601. sudo -i guix pull
  1602. @end example
  1603. @noindent
  1604. followed by (assuming your distro uses the systemd service management
  1605. tool):
  1606. @example
  1607. systemctl restart guix-daemon.service
  1608. @end example
  1609. On Guix System, upgrading the daemon is achieved by reconfiguring the
  1610. system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
  1611. @c TODO What else?
  1612. @c *********************************************************************
  1613. @node System Installation
  1614. @chapter System Installation
  1615. @cindex installing Guix System
  1616. @cindex Guix System, installation
  1617. This section explains how to install Guix System
  1618. on a machine. Guix, as a package manager, can
  1619. also be installed on top of a running GNU/Linux system,
  1620. @pxref{Installation}.
  1621. @ifinfo
  1622. @quotation Note
  1623. @c This paragraph is for people reading this from tty2 of the
  1624. @c installation image.
  1625. You are reading this documentation with an Info reader. For details on
  1626. how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
  1627. link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
  1628. Info}. Hit @kbd{l} afterwards to come back here.
  1629. Alternatively, run @command{info info} in another tty to keep the manual
  1630. available.
  1631. @end quotation
  1632. @end ifinfo
  1633. @menu
  1634. * Limitations:: What you can expect.
  1635. * Hardware Considerations:: Supported hardware.
  1636. * USB Stick and DVD Installation:: Preparing the installation medium.
  1637. * Preparing for Installation:: Networking, partitioning, etc.
  1638. * Guided Graphical Installation:: Easy graphical installation.
  1639. * Manual Installation:: Manual installation for wizards.
  1640. * After System Installation:: When installation succeeded.
  1641. * Installing Guix in a VM:: Guix System playground.
  1642. * Building the Installation Image:: How this comes to be.
  1643. @end menu
  1644. @node Limitations
  1645. @section Limitations
  1646. We consider Guix System to be ready for a wide range of ``desktop'' and server
  1647. use cases. The reliability guarantees it provides---transactional upgrades
  1648. and rollbacks, reproducibility---make it a solid foundation.
  1649. Nevertheless, before you proceed with the installation, be aware of the
  1650. following noteworthy limitations applicable to version @value{VERSION}:
  1651. @itemize
  1652. @item
  1653. More and more system services are provided (@pxref{Services}), but some
  1654. may be missing.
  1655. @item
  1656. GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
  1657. as well as a number of X11 window managers. However, KDE is currently
  1658. missing.
  1659. @end itemize
  1660. More than a disclaimer, this is an invitation to report issues (and success
  1661. stories!), and to join us in improving it. @xref{Contributing}, for more
  1662. info.
  1663. @node Hardware Considerations
  1664. @section Hardware Considerations
  1665. @cindex hardware support on Guix System
  1666. GNU@tie{}Guix focuses on respecting the user's computing freedom. It
  1667. builds around the kernel Linux-libre, which means that only hardware for
  1668. which free software drivers and firmware exist is supported. Nowadays,
  1669. a wide range of off-the-shelf hardware is supported on
  1670. GNU/Linux-libre---from keyboards to graphics cards to scanners and
  1671. Ethernet controllers. Unfortunately, there are still areas where
  1672. hardware vendors deny users control over their own computing, and such
  1673. hardware is not supported on Guix System.
  1674. @cindex WiFi, hardware support
  1675. One of the main areas where free drivers or firmware are lacking is WiFi
  1676. devices. WiFi devices known to work include those using Atheros chips
  1677. (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
  1678. driver, and those using Broadcom/AirForce chips (BCM43xx with
  1679. Wireless-Core Revision 5), which corresponds to the @code{b43-open}
  1680. Linux-libre driver. Free firmware exists for both and is available
  1681. out-of-the-box on Guix System, as part of @code{%base-firmware}
  1682. (@pxref{operating-system Reference, @code{firmware}}).
  1683. @cindex RYF, Respects Your Freedom
  1684. The @uref{https://www.fsf.org/, Free Software Foundation} runs
  1685. @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
  1686. certification program for hardware products that respect your freedom
  1687. and your privacy and ensure that you have control over your device. We
  1688. encourage you to check the list of RYF-certified devices.
  1689. Another useful resource is the @uref{https://www.h-node.org/, H-Node}
  1690. web site. It contains a catalog of hardware devices with information
  1691. about their support in GNU/Linux.
  1692. @node USB Stick and DVD Installation
  1693. @section USB Stick and DVD Installation
  1694. An ISO-9660 installation image that can be written to a USB stick or
  1695. burnt to a DVD can be downloaded from
  1696. @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
  1697. where you can replace @code{x86_64-linux} with one of:
  1698. @table @code
  1699. @item x86_64-linux
  1700. for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
  1701. @item i686-linux
  1702. for a 32-bit GNU/Linux system on Intel-compatible CPUs.
  1703. @end table
  1704. @c start duplication of authentication part from ``Binary Installation''
  1705. Make sure to download the associated @file{.sig} file and to verify the
  1706. authenticity of the image against it, along these lines:
  1707. @example
  1708. $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
  1709. $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
  1710. @end example
  1711. If that command fails because you do not have the required public key,
  1712. then run this command to import it:
  1713. @example
  1714. $ wget @value{OPENPGP-SIGNING-KEY-URL} \
  1715. -qO - | gpg --import -
  1716. @end example
  1717. @noindent
  1718. and rerun the @code{gpg --verify} command.
  1719. Take note that a warning like ``This key is not certified with a trusted
  1720. signature!'' is normal.
  1721. @c end duplication
  1722. This image contains the tools necessary for an installation.
  1723. It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
  1724. @unnumberedsubsec Copying to a USB Stick
  1725. To copy the image to a USB stick, follow these steps:
  1726. @enumerate
  1727. @item
  1728. Decompress the image using the @command{xz} command:
  1729. @example
  1730. xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
  1731. @end example
  1732. @item
  1733. Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
  1734. its device name. Assuming that the USB stick is known as @file{/dev/sdX},
  1735. copy the image with:
  1736. @example
  1737. dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
  1738. sync
  1739. @end example
  1740. Access to @file{/dev/sdX} usually requires root privileges.
  1741. @end enumerate
  1742. @unnumberedsubsec Burning on a DVD
  1743. To copy the image to a DVD, follow these steps:
  1744. @enumerate
  1745. @item
  1746. Decompress the image using the @command{xz} command:
  1747. @example
  1748. xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
  1749. @end example
  1750. @item
  1751. Insert a blank DVD into your machine, and determine
  1752. its device name. Assuming that the DVD drive is known as @file{/dev/srX},
  1753. copy the image with:
  1754. @example
  1755. growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
  1756. @end example
  1757. Access to @file{/dev/srX} usually requires root privileges.
  1758. @end enumerate
  1759. @unnumberedsubsec Booting
  1760. Once this is done, you should be able to reboot the system and boot from
  1761. the USB stick or DVD@. The latter usually requires you to get in the
  1762. BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
  1763. In order to boot from Libreboot, switch to the command mode by pressing
  1764. the @kbd{c} key and type @command{search_grub usb}.
  1765. @xref{Installing Guix in a VM}, if, instead, you would like to install
  1766. Guix System in a virtual machine (VM).
  1767. @node Preparing for Installation
  1768. @section Preparing for Installation
  1769. Once you have booted, you can use the guided graphical installer, which makes
  1770. it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
  1771. if you are already familiar with GNU/Linux and if you want more control than
  1772. what the graphical installer provides, you can choose the ``manual''
  1773. installation process (@pxref{Manual Installation}).
  1774. The graphical installer is available on TTY1. You can obtain root shells on
  1775. TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
  1776. this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
  1777. is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
  1778. Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
  1779. which allows you to select text with the left mouse button and to paste it
  1780. with the middle button.
  1781. @quotation Note
  1782. Installation requires access to the Internet so that any missing
  1783. dependencies of your system configuration can be downloaded. See the
  1784. ``Networking'' section below.
  1785. @end quotation
  1786. @node Guided Graphical Installation
  1787. @section Guided Graphical Installation
  1788. The graphical installer is a text-based user interface. It will guide you,
  1789. with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
  1790. The first dialog boxes allow you to set up the system as you use it during the
  1791. installation: you can choose the language, keyboard layout, and set up
  1792. networking, which will be used during the installation. The image below shows
  1793. the networking dialog.
  1794. @image{images/installer-network,5in,, networking setup with the graphical installer}
  1795. Later steps allow you to partition your hard disk, as shown in the image
  1796. below, to choose whether or not to use encrypted file systems, to enter the
  1797. host name and root password, and to create an additional account, among other
  1798. things.
  1799. @image{images/installer-partitions,5in,, partitioning with the graphical installer}
  1800. Note that, at any time, the installer allows you to exit the current
  1801. installation step and resume at a previous step, as show in the image below.
  1802. @image{images/installer-resume,5in,, resuming the installation process}
  1803. Once you're done, the installer produces an operating system configuration and
  1804. displays it (@pxref{Using the Configuration System}). At that point you can
  1805. hit ``OK'' and installation will proceed. On success, you can reboot into the
  1806. new system and enjoy. @xref{After System Installation}, for what's next!
  1807. @node Manual Installation
  1808. @section Manual Installation
  1809. This section describes how you would ``manually'' install GNU@tie{}Guix System
  1810. on your machine. This option requires familiarity with GNU/Linux, with the
  1811. shell, and with common administration tools. If you think this is not for
  1812. you, consider using the guided graphical installer (@pxref{Guided Graphical
  1813. Installation}).
  1814. The installation system provides root shells on TTYs 3 to 6; press
  1815. @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
  1816. many common tools needed to install the system. But it is also a full-blown
  1817. Guix System, which means that you can install additional packages, should you
  1818. need it, using @command{guix package} (@pxref{Invoking guix package}).
  1819. @menu
  1820. * Keyboard Layout and Networking and Partitioning:: Initial setup.
  1821. * Proceeding with the Installation:: Installing.
  1822. @end menu
  1823. @node Keyboard Layout and Networking and Partitioning
  1824. @subsection Keyboard Layout, Networking, and Partitioning
  1825. Before you can install the system, you may want to adjust the keyboard layout,
  1826. set up networking, and partition your target hard disk. This section will
  1827. guide you through this.
  1828. @subsubsection Keyboard Layout
  1829. @cindex keyboard layout
  1830. The installation image uses the US qwerty keyboard layout. If you want
  1831. to change it, you can use the @command{loadkeys} command. For example,
  1832. the following command selects the Dvorak keyboard layout:
  1833. @example
  1834. loadkeys dvorak
  1835. @end example
  1836. See the files under @file{/run/current-system/profile/share/keymaps} for
  1837. a list of available keyboard layouts. Run @command{man loadkeys} for
  1838. more information.
  1839. @subsubsection Networking
  1840. Run the following command to see what your network interfaces are called:
  1841. @example
  1842. ifconfig -a
  1843. @end example
  1844. @noindent
  1845. @dots{} or, using the GNU/Linux-specific @command{ip} command:
  1846. @example
  1847. ip address
  1848. @end example
  1849. @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
  1850. Wired interfaces have a name starting with @samp{e}; for example, the
  1851. interface corresponding to the first on-board Ethernet controller is
  1852. called @samp{eno1}. Wireless interfaces have a name starting with
  1853. @samp{w}, like @samp{w1p2s0}.
  1854. @table @asis
  1855. @item Wired connection
  1856. To configure a wired network run the following command, substituting
  1857. @var{interface} with the name of the wired interface you want to use.
  1858. @example
  1859. ifconfig @var{interface} up
  1860. @end example
  1861. @noindent
  1862. @dots{} or, using the GNU/Linux-specific @command{ip} command:
  1863. @example
  1864. ip link set @var{interface} up
  1865. @end example
  1866. @item Wireless connection
  1867. @cindex wireless
  1868. @cindex WiFi
  1869. To configure wireless networking, you can create a configuration file
  1870. for the @command{wpa_supplicant} configuration tool (its location is not
  1871. important) using one of the available text editors such as
  1872. @command{nano}:
  1873. @example
  1874. nano wpa_supplicant.conf
  1875. @end example
  1876. As an example, the following stanza can go to this file and will work
  1877. for many wireless networks, provided you give the actual SSID and
  1878. passphrase for the network you are connecting to:
  1879. @example
  1880. network=@{
  1881. ssid="@var{my-ssid}"
  1882. key_mgmt=WPA-PSK
  1883. psk="the network's secret passphrase"
  1884. @}
  1885. @end example
  1886. Start the wireless service and run it in the background with the
  1887. following command (substitute @var{interface} with the name of the
  1888. network interface you want to use):
  1889. @example
  1890. wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
  1891. @end example
  1892. Run @command{man wpa_supplicant} for more information.
  1893. @end table
  1894. @cindex DHCP
  1895. At this point, you need to acquire an IP address. On a network where IP
  1896. addresses are automatically assigned @i{via} DHCP, you can run:
  1897. @example
  1898. dhclient -v @var{interface}
  1899. @end example
  1900. Try to ping a server to see if networking is up and running:
  1901. @example
  1902. ping -c 3 gnu.org
  1903. @end example
  1904. Setting up network access is almost always a requirement because the
  1905. image does not contain all the software and tools that may be needed.
  1906. @cindex proxy, during system installation
  1907. If you need HTTP and HTTPS access to go through a proxy, run the
  1908. following command:
  1909. @example
  1910. herd set-http-proxy guix-daemon @var{URL}
  1911. @end example
  1912. @noindent
  1913. where @var{URL} is the proxy URL, for example
  1914. @code{http://example.org:8118}.
  1915. @cindex installing over SSH
  1916. If you want to, you can continue the installation remotely by starting
  1917. an SSH server:
  1918. @example
  1919. herd start ssh-daemon
  1920. @end example
  1921. Make sure to either set a password with @command{passwd}, or configure
  1922. OpenSSH public key authentication before logging in.
  1923. @subsubsection Disk Partitioning
  1924. Unless this has already been done, the next step is to partition, and
  1925. then format the target partition(s).
  1926. The installation image includes several partitioning tools, including
  1927. Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
  1928. @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
  1929. the partition layout you want:
  1930. @example
  1931. cfdisk
  1932. @end example
  1933. If your disk uses the GUID Partition Table (GPT) format and you plan to
  1934. install BIOS-based GRUB (which is the default), make sure a BIOS Boot
  1935. Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
  1936. manual}).
  1937. @cindex EFI, installation
  1938. @cindex UEFI, installation
  1939. @cindex ESP, EFI system partition
  1940. If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
  1941. (ESP) is required. This partition can be mounted at @file{/boot/efi} for
  1942. instance and must have the @code{esp} flag set. E.g., for @command{parted}:
  1943. @example
  1944. parted /dev/sda set 1 esp on
  1945. @end example
  1946. @quotation Note
  1947. @vindex grub-bootloader
  1948. @vindex grub-efi-bootloader
  1949. Unsure whether to use EFI- or BIOS-based GRUB? If the directory
  1950. @file{/sys/firmware/efi} exists in the installation image, then you should
  1951. probably perform an EFI installation, using @code{grub-efi-bootloader}.
  1952. Otherwise you should use the BIOS-based GRUB, known as
  1953. @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
  1954. bootloaders.
  1955. @end quotation
  1956. Once you are done partitioning the target hard disk drive, you have to
  1957. create a file system on the relevant partition(s)@footnote{Currently
  1958. Guix System only supports ext4, btrfs, JFS, and F2FS file systems. In
  1959. particular, code that reads file system UUIDs and labels only works for these
  1960. file system types.}. For the ESP, if you have one and assuming it is
  1961. @file{/dev/sda1}, run:
  1962. @example
  1963. mkfs.fat -F32 /dev/sda1
  1964. @end example
  1965. For the root file system, ext4 is the most widely used format. Other
  1966. file systems, such as Btrfs, support compression, which is reported to
  1967. nicely complement file deduplication that the daemon performs
  1968. independently of the file system (@pxref{Invoking guix-daemon,
  1969. deduplication}).
  1970. Preferably, assign file systems a label so that you can easily and
  1971. reliably refer to them in @code{file-system} declarations (@pxref{File
  1972. Systems}). This is typically done using the @code{-L} option of
  1973. @command{mkfs.ext4} and related commands. So, assuming the target root
  1974. partition lives at @file{/dev/sda2}, a file system with the label
  1975. @code{my-root} can be created with:
  1976. @example
  1977. mkfs.ext4 -L my-root /dev/sda2
  1978. @end example
  1979. @cindex encrypted disk
  1980. If you are instead planning to encrypt the root partition, you can use
  1981. the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
  1982. @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
  1983. @code{man cryptsetup}} for more information). Assuming you want to
  1984. store the root partition on @file{/dev/sda2}, the command sequence would
  1985. be along these lines:
  1986. @example
  1987. cryptsetup luksFormat /dev/sda2
  1988. cryptsetup open --type luks /dev/sda2 my-partition
  1989. mkfs.ext4 -L my-root /dev/mapper/my-partition
  1990. @end example
  1991. Once that is done, mount the target file system under @file{/mnt}
  1992. with a command like (again, assuming @code{my-root} is the label of the
  1993. root file system):
  1994. @example
  1995. mount LABEL=my-root /mnt
  1996. @end example
  1997. Also mount any other file systems you would like to use on the target
  1998. system relative to this path. If you have opted for @file{/boot/efi} as an
  1999. EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
  2000. found by @code{guix system init} afterwards.
  2001. Finally, if you plan to use one or more swap partitions (@pxref{Memory
  2002. Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
  2003. sure to initialize them with @command{mkswap}. Assuming you have one
  2004. swap partition on @file{/dev/sda3}, you would run:
  2005. @example
  2006. mkswap /dev/sda3
  2007. swapon /dev/sda3
  2008. @end example
  2009. Alternatively, you may use a swap file. For example, assuming that in
  2010. the new system you want to use the file @file{/swapfile} as a swap file,
  2011. you would run@footnote{This example will work for many types of file
  2012. systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
  2013. btrfs), the required steps may be different. For details, see the
  2014. manual pages for @command{mkswap} and @command{swapon}.}:
  2015. @example
  2016. # This is 10 GiB of swap space. Adjust "count" to change the size.
  2017. dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
  2018. # For security, make the file readable and writable only by root.
  2019. chmod 600 /mnt/swapfile
  2020. mkswap /mnt/swapfile
  2021. swapon /mnt/swapfile
  2022. @end example
  2023. Note that if you have encrypted the root partition and created a swap
  2024. file in its file system as described above, then the encryption also
  2025. protects the swap file, just like any other file in that file system.
  2026. @node Proceeding with the Installation
  2027. @subsection Proceeding with the Installation
  2028. With the target partitions ready and the target root mounted on
  2029. @file{/mnt}, we're ready to go. First, run:
  2030. @example
  2031. herd start cow-store /mnt
  2032. @end example
  2033. This makes @file{/gnu/store} copy-on-write, such that packages added to it
  2034. during the installation phase are written to the target disk on @file{/mnt}
  2035. rather than kept in memory. This is necessary because the first phase of
  2036. the @command{guix system init} command (see below) entails downloads or
  2037. builds to @file{/gnu/store} which, initially, is an in-memory file system.
  2038. Next, you have to edit a file and
  2039. provide the declaration of the operating system to be installed. To
  2040. that end, the installation system comes with three text editors. We
  2041. recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
  2042. supports syntax highlighting and parentheses matching; other editors
  2043. include GNU Zile (an Emacs clone), and
  2044. nvi (a clone of the original BSD @command{vi} editor).
  2045. We strongly recommend storing that file on the target root file system, say,
  2046. as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
  2047. configuration file once you have rebooted into the newly-installed system.
  2048. @xref{Using the Configuration System}, for an overview of the
  2049. configuration file. The example configurations discussed in that
  2050. section are available under @file{/etc/configuration} in the
  2051. installation image. Thus, to get started with a system configuration
  2052. providing a graphical display server (a ``desktop'' system), you can run
  2053. something along these lines:
  2054. @example
  2055. # mkdir /mnt/etc
  2056. # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
  2057. # nano /mnt/etc/config.scm
  2058. @end example
  2059. You should pay attention to what your configuration file contains, and
  2060. in particular:
  2061. @itemize
  2062. @item
  2063. Make sure the @code{bootloader-configuration} form refers to the target
  2064. you want to install GRUB on. It should mention @code{grub-bootloader} if
  2065. you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
  2066. for newer UEFI systems. For legacy systems, the @code{target} field
  2067. names a device, like @code{/dev/sda}; for UEFI systems it names a path
  2068. to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
  2069. currently mounted and a @code{file-system} entry is specified in your
  2070. configuration.
  2071. @item
  2072. Be sure that your file system labels match the value of their respective
  2073. @code{device} fields in your @code{file-system} configuration, assuming
  2074. your @code{file-system} configuration uses the @code{file-system-label}
  2075. procedure in its @code{device} field.
  2076. @item
  2077. If there are encrypted or RAID partitions, make sure to add a
  2078. @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
  2079. @end itemize
  2080. Once you are done preparing the configuration file, the new system must
  2081. be initialized (remember that the target root file system is mounted
  2082. under @file{/mnt}):
  2083. @example
  2084. guix system init /mnt/etc/config.scm /mnt
  2085. @end example
  2086. @noindent
  2087. This copies all the necessary files and installs GRUB on
  2088. @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
  2089. more information, @pxref{Invoking guix system}. This command may trigger
  2090. downloads or builds of missing packages, which can take some time.
  2091. Once that command has completed---and hopefully succeeded!---you can run
  2092. @command{reboot} and boot into the new system. The @code{root} password
  2093. in the new system is initially empty; other users' passwords need to be
  2094. initialized by running the @command{passwd} command as @code{root},
  2095. unless your configuration specifies otherwise
  2096. (@pxref{user-account-password, user account passwords}).
  2097. @xref{After System Installation}, for what's next!
  2098. @node After System Installation
  2099. @section After System Installation
  2100. Success, you've now booted into Guix System! From then on, you can update the
  2101. system whenever you want by running, say:
  2102. @example
  2103. guix pull
  2104. sudo guix system reconfigure /etc/config.scm
  2105. @end example
  2106. @noindent
  2107. This builds a new system generation with the latest packages and services
  2108. (@pxref{Invoking guix system}). We recommend doing that regularly so that
  2109. your system includes the latest security updates (@pxref{Security Updates}).
  2110. @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
  2111. @quotation Note
  2112. @cindex sudo vs. @command{guix pull}
  2113. Note that @command{sudo guix} runs your user's @command{guix} command and
  2114. @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
  2115. explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
  2116. The difference matters here, because @command{guix pull} updates
  2117. the @command{guix} command and package definitions only for the user it is ran
  2118. as. This means that if you choose to use @command{guix system reconfigure} in
  2119. root's login shell, you'll need to @command{guix pull} separately.
  2120. @end quotation
  2121. Now, @pxref{Getting Started}, and
  2122. join us on @code{#guix} on the Freenode IRC network or on
  2123. @email{guix-devel@@gnu.org} to share your experience!
  2124. @node Installing Guix in a VM
  2125. @section Installing Guix in a Virtual Machine
  2126. @cindex virtual machine, Guix System installation
  2127. @cindex virtual private server (VPS)
  2128. @cindex VPS (virtual private server)
  2129. If you'd like to install Guix System in a virtual machine (VM) or on a
  2130. virtual private server (VPS) rather than on your beloved machine, this
  2131. section is for you.
  2132. To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
  2133. disk image, follow these steps:
  2134. @enumerate
  2135. @item
  2136. First, retrieve and decompress the Guix system installation image as
  2137. described previously (@pxref{USB Stick and DVD Installation}).
  2138. @item
  2139. Create a disk image that will hold the installed system. To make a
  2140. qcow2-formatted disk image, use the @command{qemu-img} command:
  2141. @example
  2142. qemu-img create -f qcow2 guix-system.img 50G
  2143. @end example
  2144. The resulting file will be much smaller than 50 GB (typically less than
  2145. 1 MB), but it will grow as the virtualized storage device is filled up.
  2146. @item
  2147. Boot the USB installation image in an VM:
  2148. @example
  2149. qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
  2150. -nic user,model=virtio-net-pci -boot menu=on,order=d \
  2151. -drive file=guix-system.img \
  2152. -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
  2153. @end example
  2154. @code{-enable-kvm} is optional, but significantly improves performance,
  2155. @pxref{Running Guix in a VM}.
  2156. @item
  2157. You're now root in the VM, proceed with the installation process.
  2158. @xref{Preparing for Installation}, and follow the instructions.
  2159. @end enumerate
  2160. Once installation is complete, you can boot the system that's on your
  2161. @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
  2162. that.
  2163. @node Building the Installation Image
  2164. @section Building the Installation Image
  2165. @cindex installation image
  2166. The installation image described above was built using the @command{guix
  2167. system} command, specifically:
  2168. @example
  2169. guix system image -t iso9660 gnu/system/install.scm
  2170. @end example
  2171. Have a look at @file{gnu/system/install.scm} in the source tree,
  2172. and see also @ref{Invoking guix system} for more information
  2173. about the installation image.
  2174. @section Building the Installation Image for ARM Boards
  2175. Many ARM boards require a specific variant of the
  2176. @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
  2177. If you build a disk image and the bootloader is not available otherwise
  2178. (on another boot drive etc), it's advisable to build an image that
  2179. includes the bootloader, specifically:
  2180. @example
  2181. guix system image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
  2182. @end example
  2183. @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
  2184. board, a list of possible boards will be printed.
  2185. @c *********************************************************************
  2186. @node Getting Started
  2187. @chapter Getting Started
  2188. Presumably, you've reached this section because either you have
  2189. installed Guix on top of another distribution (@pxref{Installation}), or
  2190. you've installed the standalone Guix System (@pxref{System
  2191. Installation}). It's time for you to get started using Guix and this
  2192. section aims to help you do that and give you a feel of what it's like.
  2193. Guix is about installing software, so probably the first thing you'll
  2194. want to do is to actually look for software. Let's say you're looking
  2195. for a text editor, you can run:
  2196. @example
  2197. guix search text editor
  2198. @end example
  2199. This command shows you a number of matching @dfn{packages}, each time
  2200. showing the package's name, version, a description, and additional info.
  2201. Once you've found out the one you want to use, let's say Emacs (ah ha!),
  2202. you can go ahead and install it (run this command as a regular user,
  2203. @emph{no need for root privileges}!):
  2204. @example
  2205. guix install emacs
  2206. @end example
  2207. You've installed your first package, congrats! In the process, you've
  2208. probably noticed that Guix downloaded pre-built binaries; or, if you
  2209. explicitly chose to @emph{not} use pre-built binaries, then probably
  2210. Guix is still building software (@pxref{Substitutes}, for more info).
  2211. Unless you're using Guix System, the @command{guix install} command must
  2212. have printed this hint:
  2213. @example
  2214. hint: Consider setting the necessary environment variables by running:
  2215. GUIX_PROFILE="$HOME/.guix-profile"
  2216. . "$GUIX_PROFILE/etc/profile"
  2217. Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
  2218. @end example
  2219. Indeed, you must now tell your shell where @command{emacs} and other
  2220. programs installed with Guix are to be found. Pasting the two lines
  2221. above will do just that: it will add
  2222. @code{$HOME/.guix-profile/bin}---which is where the installed package
  2223. is---to the @code{PATH} environment variable. You can paste these two
  2224. lines in your shell so they take effect right away, but more importantly
  2225. you should add them to @file{~/.bash_profile} (or equivalent file if you
  2226. do not use Bash) so that environment variables are set next time you
  2227. spawn a shell. You only need to do this once and other search paths
  2228. environment variables will be taken care of similarly---e.g., if you
  2229. eventually install @code{python} and Python libraries, @code{PYTHONPATH}
  2230. will be defined.
  2231. You can go on installing packages at your will. To list installed
  2232. packages, run:
  2233. @example
  2234. guix package --list-installed
  2235. @end example
  2236. To remove a package, you would unsurprisingly run @command{guix remove}.
  2237. A distinguishing feature is the ability to @dfn{roll back} any operation
  2238. you made---installation, removal, upgrade---by simply typing:
  2239. @example
  2240. guix package --roll-back
  2241. @end example
  2242. This is because each operation is in fact a @dfn{transaction} that
  2243. creates a new @dfn{generation}. These generations and the difference
  2244. between them can be displayed by running:
  2245. @example
  2246. guix package --list-generations
  2247. @end example
  2248. Now you know the basics of package management!
  2249. @quotation Going further
  2250. @xref{Package Management}, for more about package management. You may
  2251. like @dfn{declarative} package management with @command{guix package
  2252. --manifest}, managing separate @dfn{profiles} with @option{--profile},
  2253. deleting old generations, collecting garbage, and other nifty features
  2254. that will come in handy as you become more familiar with Guix. If you
  2255. are a developer, @pxref{Development} for additional tools. And if
  2256. you're curious, @pxref{Features}, to peek under the hood.
  2257. @end quotation
  2258. Once you've installed a set of packages, you will want to periodically
  2259. @emph{upgrade} them to the latest and greatest version. To do that, you
  2260. will first pull the latest revision of Guix and its package collection:
  2261. @example
  2262. guix pull
  2263. @end example
  2264. The end result is a new @command{guix} command, under
  2265. @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
  2266. first time you run @command{guix pull}, be sure to follow the hint that
  2267. the command prints and, similar to what we saw above, paste these two
  2268. lines in your terminal and @file{.bash_profile}:
  2269. @example
  2270. GUIX_PROFILE="$HOME/.config/guix/current"
  2271. . "$GUIX_PROFILE/etc/profile"
  2272. @end example
  2273. @noindent
  2274. You must also instruct your shell to point to this new @command{guix}:
  2275. @example
  2276. hash guix
  2277. @end example
  2278. At this point, you're running a brand new Guix. You can thus go ahead
  2279. and actually upgrade all the packages you previously installed:
  2280. @example
  2281. guix upgrade
  2282. @end example
  2283. As you run this command, you will see that binaries are downloaded (or
  2284. perhaps some packages are built), and eventually you end up with the
  2285. upgraded packages. Should one of these upgraded packages not be to your
  2286. liking, remember you can always roll back!
  2287. You can display the exact revision of Guix you're currently using by
  2288. running:
  2289. @example
  2290. guix describe
  2291. @end example
  2292. The information it displays is @emph{all it takes to reproduce the exact
  2293. same Guix}, be it at a different point in time or on a different
  2294. machine.
  2295. @quotation Going further
  2296. @xref{Invoking guix pull}, for more information. @xref{Channels}, on
  2297. how to specify additional @dfn{channels} to pull packages from, how to
  2298. replicate Guix, and more. You may also find @command{time-machine}
  2299. handy (@pxref{Invoking guix time-machine}).
  2300. @end quotation
  2301. If you installed Guix System, one of the first things you'll want to do
  2302. is to upgrade your system. Once you've run @command{guix pull} to get
  2303. the latest Guix, you can upgrade the system like this:
  2304. @example
  2305. sudo guix system reconfigure /etc/config.scm
  2306. @end example
  2307. Upon completion, the system runs the latest versions of its software
  2308. packages. When you eventually reboot, you'll notice a sub-menu in the
  2309. bootloader that reads ``Old system generations'': it's what allows you
  2310. to boot @emph{an older generation of your system}, should the latest
  2311. generation be ``broken'' or otherwise unsatisfying. Just like for
  2312. packages, you can always @emph{roll back} to a previous generation
  2313. @emph{of the whole system}:
  2314. @example
  2315. sudo guix system roll-back
  2316. @end example
  2317. There are many things you'll probably want to tweak on your system:
  2318. adding new user accounts, adding new system services, fiddling with the
  2319. configuration of those services, etc. The system configuration is
  2320. @emph{entirely} described in the @file{/etc/config.scm} file.
  2321. @xref{Using the Configuration System}, to learn how to change it.
  2322. Now you know enough to get started!
  2323. @quotation Resources
  2324. The rest of this manual provides a reference for all things Guix. Here
  2325. are some additional resources you may find useful:
  2326. @itemize
  2327. @item
  2328. @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
  2329. ``how-to'' style of recipes for a variety of applications.
  2330. @item
  2331. The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
  2332. Card} lists in two pages most of the commands and options you'll ever
  2333. need.
  2334. @item
  2335. The web site contains @uref{https://guix.gnu.org/en/videos/,
  2336. instructional videos} covering topics such as everyday use of Guix, how
  2337. to get help, and how to become a contributor.
  2338. @item
  2339. @xref{Documentation}, to learn how to access documentation on your
  2340. computer.
  2341. @end itemize
  2342. We hope you will enjoy Guix as much as the community enjoys building it!
  2343. @end quotation
  2344. @c *********************************************************************
  2345. @node Package Management
  2346. @chapter Package Management
  2347. @cindex packages
  2348. The purpose of GNU Guix is to allow users to easily install, upgrade, and
  2349. remove software packages, without having to know about their build
  2350. procedures or dependencies. Guix also goes beyond this obvious set of
  2351. features.
  2352. This chapter describes the main features of Guix, as well as the
  2353. package management tools it provides. Along with the command-line
  2354. interface described below (@pxref{Invoking guix package, @code{guix
  2355. package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
  2356. emacs-guix, The Emacs-Guix Reference Manual}), after installing
  2357. @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
  2358. with it):
  2359. @example
  2360. guix install emacs-guix
  2361. @end example
  2362. @menu
  2363. * Features:: How Guix will make your life brighter.
  2364. * Invoking guix package:: Package installation, removal, etc.
  2365. * Substitutes:: Downloading pre-built binaries.
  2366. * Packages with Multiple Outputs:: Single source package, multiple outputs.
  2367. * Invoking guix gc:: Running the garbage collector.
  2368. * Invoking guix pull:: Fetching the latest Guix and distribution.
  2369. * Invoking guix time-machine:: Running an older revision of Guix.
  2370. * Inferiors:: Interacting with another revision of Guix.
  2371. * Invoking guix describe:: Display information about your Guix revision.
  2372. * Invoking guix archive:: Exporting and importing store files.
  2373. @end menu
  2374. @node Features
  2375. @section Features
  2376. Here we assume you've already made your first steps with Guix
  2377. (@pxref{Getting Started}) and would like to get an overview about what's
  2378. going on under the hood.
  2379. When using Guix, each package ends up in the @dfn{package store}, in its
  2380. own directory---something that resembles
  2381. @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
  2382. Instead of referring to these directories, users have their own
  2383. @dfn{profile}, which points to the packages that they actually want to
  2384. use. These profiles are stored within each user's home directory, at
  2385. @code{$HOME/.guix-profile}.
  2386. For example, @code{alice} installs GCC 4.7.2. As a result,
  2387. @file{/home/alice/.guix-profile/bin/gcc} points to
  2388. @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
  2389. @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
  2390. simply continues to point to
  2391. @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
  2392. coexist on the same system without any interference.
  2393. The @command{guix package} command is the central tool to manage
  2394. packages (@pxref{Invoking guix package}). It operates on the per-user
  2395. profiles, and can be used @emph{with normal user privileges}.
  2396. @cindex transactions
  2397. The command provides the obvious install, remove, and upgrade
  2398. operations. Each invocation is actually a @emph{transaction}: either
  2399. the specified operation succeeds, or nothing happens. Thus, if the
  2400. @command{guix package} process is terminated during the transaction,
  2401. or if a power outage occurs during the transaction, then the user's
  2402. profile remains in its previous state, and remains usable.
  2403. In addition, any package transaction may be @emph{rolled back}. So, if,
  2404. for example, an upgrade installs a new version of a package that turns
  2405. out to have a serious bug, users may roll back to the previous instance
  2406. of their profile, which was known to work well. Similarly, the global
  2407. system configuration on Guix is subject to
  2408. transactional upgrades and roll-back
  2409. (@pxref{Using the Configuration System}).
  2410. All packages in the package store may be @emph{garbage-collected}.
  2411. Guix can determine which packages are still referenced by user
  2412. profiles, and remove those that are provably no longer referenced
  2413. (@pxref{Invoking guix gc}). Users may also explicitly remove old
  2414. generations of their profile so that the packages they refer to can be
  2415. collected.
  2416. @cindex reproducibility
  2417. @cindex reproducible builds
  2418. Guix takes a @dfn{purely functional} approach to package
  2419. management, as described in the introduction (@pxref{Introduction}).
  2420. Each @file{/gnu/store} package directory name contains a hash of all the
  2421. inputs that were used to build that package---compiler, libraries, build
  2422. scripts, etc. This direct correspondence allows users to make sure a
  2423. given package installation matches the current state of their
  2424. distribution. It also helps maximize @dfn{build reproducibility}:
  2425. thanks to the isolated build environments that are used, a given build
  2426. is likely to yield bit-identical files when performed on different
  2427. machines (@pxref{Invoking guix-daemon, container}).
  2428. @cindex substitutes
  2429. This foundation allows Guix to support @dfn{transparent binary/source
  2430. deployment}. When a pre-built binary for a @file{/gnu/store} item is
  2431. available from an external source---a @dfn{substitute}, Guix just
  2432. downloads it and unpacks it;
  2433. otherwise, it builds the package from source, locally
  2434. (@pxref{Substitutes}). Because build results are usually bit-for-bit
  2435. reproducible, users do not have to trust servers that provide
  2436. substitutes: they can force a local build and @emph{challenge} providers
  2437. (@pxref{Invoking guix challenge}).
  2438. Control over the build environment is a feature that is also useful for
  2439. developers. The @command{guix environment} command allows developers of
  2440. a package to quickly set up the right development environment for their
  2441. package, without having to manually install the dependencies of the
  2442. package into their profile (@pxref{Invoking guix environment}).
  2443. @cindex replication, of software environments
  2444. @cindex provenance tracking, of software artifacts
  2445. All of Guix and its package definitions is version-controlled, and
  2446. @command{guix pull} allows you to ``travel in time'' on the history of Guix
  2447. itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
  2448. Guix instance on a different machine or at a later point in time, which in
  2449. turn allows you to @emph{replicate complete software environments}, while
  2450. retaining precise @dfn{provenance tracking} of the software.
  2451. @node Invoking guix package
  2452. @section Invoking @command{guix package}
  2453. @cindex installing packages
  2454. @cindex removing packages
  2455. @cindex package installation
  2456. @cindex package removal
  2457. The @command{guix package} command is the tool that allows users to
  2458. install, upgrade, and remove packages, as well as rolling back to
  2459. previous configurations. It operates only on the user's own profile,
  2460. and works with normal user privileges (@pxref{Features}). Its syntax
  2461. is:
  2462. @example
  2463. guix package @var{options}
  2464. @end example
  2465. @cindex transactions
  2466. Primarily, @var{options} specifies the operations to be performed during
  2467. the transaction. Upon completion, a new profile is created, but
  2468. previous @dfn{generations} of the profile remain available, should the user
  2469. want to roll back.
  2470. For example, to remove @code{lua} and install @code{guile} and
  2471. @code{guile-cairo} in a single transaction:
  2472. @example
  2473. guix package -r lua -i guile guile-cairo
  2474. @end example
  2475. @cindex aliases, for @command{guix package}
  2476. For your convenience, we also provide the following aliases:
  2477. @itemize
  2478. @item
  2479. @command{guix search} is an alias for @command{guix package -s},
  2480. @item
  2481. @command{guix install} is an alias for @command{guix package -i},
  2482. @item
  2483. @command{guix remove} is an alias for @command{guix package -r},
  2484. @item
  2485. @command{guix upgrade} is an alias for @command{guix package -u},
  2486. @item
  2487. and @command{guix show} is an alias for @command{guix package --show=}.
  2488. @end itemize
  2489. These aliases are less expressive than @command{guix package} and provide
  2490. fewer options, so in some cases you'll probably want to use @command{guix
  2491. package} directly.
  2492. @command{guix package} also supports a @dfn{declarative approach}
  2493. whereby the user specifies the exact set of packages to be available and
  2494. passes it @i{via} the @option{--manifest} option
  2495. (@pxref{profile-manifest, @option{--manifest}}).
  2496. @cindex profile
  2497. For each user, a symlink to the user's default profile is automatically
  2498. created in @file{$HOME/.guix-profile}. This symlink always points to the
  2499. current generation of the user's default profile. Thus, users can add
  2500. @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
  2501. variable, and so on.
  2502. @cindex search paths
  2503. If you are not using Guix System, consider adding the
  2504. following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
  2505. Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
  2506. shells get all the right environment variable definitions:
  2507. @example
  2508. GUIX_PROFILE="$HOME/.guix-profile" ; \
  2509. source "$GUIX_PROFILE/etc/profile"
  2510. @end example
  2511. In a multi-user setup, user profiles are stored in a place registered as
  2512. a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
  2513. to (@pxref{Invoking guix gc}). That directory is normally
  2514. @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
  2515. @var{localstatedir} is the value passed to @code{configure} as
  2516. @option{--localstatedir}, and @var{user} is the user name. The
  2517. @file{per-user} directory is created when @command{guix-daemon} is
  2518. started, and the @var{user} sub-directory is created by @command{guix
  2519. package}.
  2520. The @var{options} can be among the following:
  2521. @table @code
  2522. @item --install=@var{package} @dots{}
  2523. @itemx -i @var{package} @dots{}
  2524. Install the specified @var{package}s.
  2525. Each @var{package} may specify either a simple package name, such as
  2526. @code{guile}, or a package name followed by an at-sign and version number,
  2527. such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
  2528. case, the newest version prefixed by @code{1.8} is selected).
  2529. If no version number is specified, the
  2530. newest available version will be selected. In addition, @var{package}
  2531. may contain a colon, followed by the name of one of the outputs of the
  2532. package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
  2533. (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
  2534. name (and optionally version) are searched for among the GNU
  2535. distribution modules (@pxref{Package Modules}).
  2536. @cindex propagated inputs
  2537. Sometimes packages have @dfn{propagated inputs}: these are dependencies
  2538. that automatically get installed along with the required package
  2539. (@pxref{package-propagated-inputs, @code{propagated-inputs} in
  2540. @code{package} objects}, for information about propagated inputs in
  2541. package definitions).
  2542. @anchor{package-cmd-propagated-inputs}
  2543. An example is the GNU MPC library: its C header files refer to those of
  2544. the GNU MPFR library, which in turn refer to those of the GMP library.
  2545. Thus, when installing MPC, the MPFR and GMP libraries also get installed
  2546. in the profile; removing MPC also removes MPFR and GMP---unless they had
  2547. also been explicitly installed by the user.
  2548. Besides, packages sometimes rely on the definition of environment
  2549. variables for their search paths (see explanation of
  2550. @option{--search-paths} below). Any missing or possibly incorrect
  2551. environment variable definitions are reported here.
  2552. @item --install-from-expression=@var{exp}
  2553. @itemx -e @var{exp}
  2554. Install the package @var{exp} evaluates to.
  2555. @var{exp} must be a Scheme expression that evaluates to a
  2556. @code{<package>} object. This option is notably useful to disambiguate
  2557. between same-named variants of a package, with expressions such as
  2558. @code{(@@ (gnu packages base) guile-final)}.
  2559. Note that this option installs the first output of the specified
  2560. package, which may be insufficient when needing a specific output of a
  2561. multiple-output package.
  2562. @item --install-from-file=@var{file}
  2563. @itemx -f @var{file}
  2564. Install the package that the code within @var{file} evaluates to.
  2565. As an example, @var{file} might contain a definition like this
  2566. (@pxref{Defining Packages}):
  2567. @lisp
  2568. @include package-hello.scm
  2569. @end lisp
  2570. Developers may find it useful to include such a @file{guix.scm} file
  2571. in the root of their project source tree that can be used to test
  2572. development snapshots and create reproducible development environments
  2573. (@pxref{Invoking guix environment}).
  2574. The @var{file} may also contain a JSON representation of one or more
  2575. package definitions. Running @code{guix package -f} on
  2576. @file{hello.json} with the following contents would result in installing
  2577. the package @code{greeter} after building @code{myhello}:
  2578. @example
  2579. @verbatiminclude package-hello.json
  2580. @end example
  2581. @item --remove=@var{package} @dots{}
  2582. @itemx -r @var{package} @dots{}
  2583. Remove the specified @var{package}s.
  2584. As for @option{--install}, each @var{package} may specify a version number
  2585. and/or output name in addition to the package name. For instance,
  2586. @samp{-r glibc:debug} would remove the @code{debug} output of
  2587. @code{glibc}.
  2588. @item --upgrade[=@var{regexp} @dots{}]
  2589. @itemx -u [@var{regexp} @dots{}]
  2590. @cindex upgrading packages
  2591. Upgrade all the installed packages. If one or more @var{regexp}s are
  2592. specified, upgrade only installed packages whose name matches a
  2593. @var{regexp}. Also see the @option{--do-not-upgrade} option below.
  2594. Note that this upgrades package to the latest version of packages found
  2595. in the distribution currently installed. To update your distribution,
  2596. you should regularly run @command{guix pull} (@pxref{Invoking guix
  2597. pull}).
  2598. @cindex package transformations, upgrades
  2599. When upgrading, package transformations that were originally applied
  2600. when creating the profile are automatically re-applied (@pxref{Package
  2601. Transformation Options}). For example, assume you first installed Emacs
  2602. from the tip of its development branch with:
  2603. @example
  2604. guix install emacs-next --with-branch=emacs-next=master
  2605. @end example
  2606. Next time you run @command{guix upgrade}, Guix will again pull the tip
  2607. of the Emacs development branch and build @code{emacs-next} from that
  2608. checkout.
  2609. Note that transformation options such as @option{--with-branch} and
  2610. @option{--with-source} depend on external state; it is up to you to
  2611. ensure that they work as expected. You can also discard a
  2612. transformations that apply to a package by running:
  2613. @example
  2614. guix install @var{package}
  2615. @end example
  2616. @item --do-not-upgrade[=@var{regexp} @dots{}]
  2617. When used together with the @option{--upgrade} option, do @emph{not}
  2618. upgrade any packages whose name matches a @var{regexp}. For example, to
  2619. upgrade all packages in the current profile except those containing the
  2620. substring ``emacs'':
  2621. @example
  2622. $ guix package --upgrade . --do-not-upgrade emacs
  2623. @end example
  2624. @item @anchor{profile-manifest}--manifest=@var{file}
  2625. @itemx -m @var{file}
  2626. @cindex profile declaration
  2627. @cindex profile manifest
  2628. Create a new generation of the profile from the manifest object
  2629. returned by the Scheme code in @var{file}. This option can be repeated
  2630. several times, in which case the manifests are concatenated.
  2631. This allows you to @emph{declare} the profile's contents rather than
  2632. constructing it through a sequence of @option{--install} and similar
  2633. commands. The advantage is that @var{file} can be put under version
  2634. control, copied to different machines to reproduce the same profile, and
  2635. so on.
  2636. @c FIXME: Add reference to (guix profile) documentation when available.
  2637. @var{file} must return a @dfn{manifest} object, which is roughly a list
  2638. of packages:
  2639. @findex packages->manifest
  2640. @lisp
  2641. (use-package-modules guile emacs)
  2642. (packages->manifest
  2643. (list emacs
  2644. guile-2.0
  2645. ;; Use a specific package output.
  2646. (list guile-2.0 "debug")))
  2647. @end lisp
  2648. @findex specifications->manifest
  2649. In this example we have to know which modules define the @code{emacs}
  2650. and @code{guile-2.0} variables to provide the right
  2651. @code{use-package-modules} line, which can be cumbersome. We can
  2652. instead provide regular package specifications and let
  2653. @code{specifications->manifest} look up the corresponding package
  2654. objects, like this:
  2655. @lisp
  2656. (specifications->manifest
  2657. '("emacs" "guile@@2.2" "guile@@2.2:debug"))
  2658. @end lisp
  2659. @xref{export-manifest, @option{--export-manifest}}, to learn how to
  2660. obtain a manifest file from an existing profile.
  2661. @item --roll-back
  2662. @cindex rolling back
  2663. @cindex undoing transactions
  2664. @cindex transactions, undoing
  2665. Roll back to the previous @dfn{generation} of the profile---i.e., undo
  2666. the last transaction.
  2667. When combined with options such as @option{--install}, roll back occurs
  2668. before any other actions.
  2669. When rolling back from the first generation that actually contains
  2670. installed packages, the profile is made to point to the @dfn{zeroth
  2671. generation}, which contains no files apart from its own metadata.
  2672. After having rolled back, installing, removing, or upgrading packages
  2673. overwrites previous future generations. Thus, the history of the
  2674. generations in a profile is always linear.
  2675. @item --switch-generation=@var{pattern}
  2676. @itemx -S @var{pattern}
  2677. @cindex generations
  2678. Switch to a particular generation defined by @var{pattern}.
  2679. @var{pattern} may be either a generation number or a number prefixed
  2680. with ``+'' or ``-''. The latter means: move forward/backward by a
  2681. specified number of generations. For example, if you want to return to
  2682. the latest generation after @option{--roll-back}, use
  2683. @option{--switch-generation=+1}.
  2684. The difference between @option{--roll-back} and
  2685. @option{--switch-generation=-1} is that @option{--switch-generation} will
  2686. not make a zeroth generation, so if a specified generation does not
  2687. exist, the current generation will not be changed.
  2688. @item --search-paths[=@var{kind}]
  2689. @cindex search paths
  2690. Report environment variable definitions, in Bash syntax, that may be
  2691. needed in order to use the set of installed packages. These environment
  2692. variables are used to specify @dfn{search paths} for files used by some
  2693. of the installed packages.
  2694. For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
  2695. environment variables to be defined so it can look for headers and
  2696. libraries in the user's profile (@pxref{Environment Variables,,, gcc,
  2697. Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
  2698. library are installed in the profile, then @option{--search-paths} will
  2699. suggest setting these variables to @file{@var{profile}/include} and
  2700. @file{@var{profile}/lib}, respectively.
  2701. The typical use case is to define these environment variables in the
  2702. shell:
  2703. @example
  2704. $ eval `guix package --search-paths`
  2705. @end example
  2706. @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
  2707. meaning that the returned environment variable definitions will either
  2708. be exact settings, or prefixes or suffixes of the current value of these
  2709. variables. When omitted, @var{kind} defaults to @code{exact}.
  2710. This option can also be used to compute the @emph{combined} search paths
  2711. of several profiles. Consider this example:
  2712. @example
  2713. $ guix package -p foo -i guile
  2714. $ guix package -p bar -i guile-json
  2715. $ guix package -p foo -p bar --search-paths
  2716. @end example
  2717. The last command above reports about the @env{GUILE_LOAD_PATH}
  2718. variable, even though, taken individually, neither @file{foo} nor
  2719. @file{bar} would lead to that recommendation.
  2720. @item --profile=@var{profile}
  2721. @itemx -p @var{profile}
  2722. Use @var{profile} instead of the user's default profile.
  2723. @var{profile} must be the name of a file that will be created upon
  2724. completion. Concretely, @var{profile} will be a mere symbolic link
  2725. (``symlink'') pointing to the actual profile where packages are
  2726. installed:
  2727. @example
  2728. $ guix install hello -p ~/code/my-profile
  2729. @dots{}
  2730. $ ~/code/my-profile/bin/hello
  2731. Hello, world!
  2732. @end example
  2733. All it takes to get rid of the profile is to remove this symlink and its
  2734. siblings that point to specific generations:
  2735. @example
  2736. $ rm ~/code/my-profile ~/code/my-profile-*-link
  2737. @end example
  2738. @item --list-profiles
  2739. List all the user's profiles:
  2740. @example
  2741. $ guix package --list-profiles
  2742. /home/charlie/.guix-profile
  2743. /home/charlie/code/my-profile
  2744. /home/charlie/code/devel-profile
  2745. /home/charlie/tmp/test
  2746. @end example
  2747. When running as root, list all the profiles of all the users.
  2748. @cindex collisions, in a profile
  2749. @cindex colliding packages in profiles
  2750. @cindex profile collisions
  2751. @item --allow-collisions
  2752. Allow colliding packages in the new profile. Use at your own risk!
  2753. By default, @command{guix package} reports as an error @dfn{collisions}
  2754. in the profile. Collisions happen when two or more different versions
  2755. or variants of a given package end up in the profile.
  2756. @item --bootstrap
  2757. Use the bootstrap Guile to build the profile. This option is only
  2758. useful to distribution developers.
  2759. @end table
  2760. In addition to these actions, @command{guix package} supports the
  2761. following options to query the current state of a profile, or the
  2762. availability of packages:
  2763. @table @option
  2764. @item --search=@var{regexp}
  2765. @itemx -s @var{regexp}
  2766. @anchor{guix-search}
  2767. @cindex searching for packages
  2768. List the available packages whose name, synopsis, or description matches
  2769. @var{regexp} (in a case-insensitive fashion), sorted by relevance.
  2770. Print all the metadata of matching packages in
  2771. @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
  2772. GNU recutils manual}).
  2773. This allows specific fields to be extracted using the @command{recsel}
  2774. command, for instance:
  2775. @example
  2776. $ guix package -s malloc | recsel -p name,version,relevance
  2777. name: jemalloc
  2778. version: 4.5.0
  2779. relevance: 6
  2780. name: glibc
  2781. version: 2.25
  2782. relevance: 1
  2783. name: libgc
  2784. version: 7.6.0
  2785. relevance: 1
  2786. @end example
  2787. Similarly, to show the name of all the packages available under the
  2788. terms of the GNU@tie{}LGPL version 3:
  2789. @example
  2790. $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
  2791. name: elfutils
  2792. name: gmp
  2793. @dots{}
  2794. @end example
  2795. It is also possible to refine search results using several @code{-s} flags to
  2796. @command{guix package}, or several arguments to @command{guix search}. For
  2797. example, the following command returns a list of board games (this time using
  2798. the @command{guix search} alias):
  2799. @example
  2800. $ guix search '\<board\>' game | recsel -p name
  2801. name: gnubg
  2802. @dots{}
  2803. @end example
  2804. If we were to omit @code{-s game}, we would also get software packages
  2805. that deal with printed circuit boards; removing the angle brackets
  2806. around @code{board} would further add packages that have to do with
  2807. keyboards.
  2808. And now for a more elaborate example. The following command searches
  2809. for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
  2810. libraries, and prints the name and synopsis of the matching packages:
  2811. @example
  2812. $ guix search crypto library | \
  2813. recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
  2814. @end example
  2815. @noindent
  2816. @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
  2817. information on @dfn{selection expressions} for @code{recsel -e}.
  2818. @item --show=@var{package}
  2819. Show details about @var{package}, taken from the list of available packages, in
  2820. @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
  2821. recutils manual}).
  2822. @example
  2823. $ guix package --show=python | recsel -p name,version
  2824. name: python
  2825. version: 2.7.6
  2826. name: python
  2827. version: 3.3.5
  2828. @end example
  2829. You may also specify the full name of a package to only get details about a
  2830. specific version of it (this time using the @command{guix show} alias):
  2831. @example
  2832. $ guix show python@@3.4 | recsel -p name,version
  2833. name: python
  2834. version: 3.4.3
  2835. @end example
  2836. @item --list-installed[=@var{regexp}]
  2837. @itemx -I [@var{regexp}]
  2838. List the currently installed packages in the specified profile, with the
  2839. most recently installed packages shown last. When @var{regexp} is
  2840. specified, list only installed packages whose name matches @var{regexp}.
  2841. For each installed package, print the following items, separated by
  2842. tabs: the package name, its version string, the part of the package that
  2843. is installed (for instance, @code{out} for the default output,
  2844. @code{include} for its headers, etc.), and the path of this package in
  2845. the store.
  2846. @item --list-available[=@var{regexp}]
  2847. @itemx -A [@var{regexp}]
  2848. List packages currently available in the distribution for this system
  2849. (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
  2850. available packages whose name matches @var{regexp}.
  2851. For each package, print the following items separated by tabs: its name,
  2852. its version string, the parts of the package (@pxref{Packages with
  2853. Multiple Outputs}), and the source location of its definition.
  2854. @item --list-generations[=@var{pattern}]
  2855. @itemx -l [@var{pattern}]
  2856. @cindex generations
  2857. Return a list of generations along with their creation dates; for each
  2858. generation, show the installed packages, with the most recently
  2859. installed packages shown last. Note that the zeroth generation is never
  2860. shown.
  2861. For each installed package, print the following items, separated by
  2862. tabs: the name of a package, its version string, the part of the package
  2863. that is installed (@pxref{Packages with Multiple Outputs}), and the
  2864. location of this package in the store.
  2865. When @var{pattern} is used, the command returns only matching
  2866. generations. Valid patterns include:
  2867. @itemize
  2868. @item @emph{Integers and comma-separated integers}. Both patterns denote
  2869. generation numbers. For instance, @option{--list-generations=1} returns
  2870. the first one.
  2871. And @option{--list-generations=1,8,2} outputs three generations in the
  2872. specified order. Neither spaces nor trailing commas are allowed.
  2873. @item @emph{Ranges}. @option{--list-generations=2..9} prints the
  2874. specified generations and everything in between. Note that the start of
  2875. a range must be smaller than its end.
  2876. It is also possible to omit the endpoint. For example,
  2877. @option{--list-generations=2..}, returns all generations starting from the
  2878. second one.
  2879. @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
  2880. or months by passing an integer along with the first letter of the
  2881. duration. For example, @option{--list-generations=20d} lists generations
  2882. that are up to 20 days old.
  2883. @end itemize
  2884. @item --delete-generations[=@var{pattern}]
  2885. @itemx -d [@var{pattern}]
  2886. When @var{pattern} is omitted, delete all generations except the current
  2887. one.
  2888. This command accepts the same patterns as @option{--list-generations}.
  2889. When @var{pattern} is specified, delete the matching generations. When
  2890. @var{pattern} specifies a duration, generations @emph{older} than the
  2891. specified duration match. For instance, @option{--delete-generations=1m}
  2892. deletes generations that are more than one month old.
  2893. If the current generation matches, it is @emph{not} deleted. Also, the
  2894. zeroth generation is never deleted.
  2895. Note that deleting generations prevents rolling back to them.
  2896. Consequently, this command must be used with care.
  2897. @cindex manifest, exporting
  2898. @anchor{export-manifest}
  2899. @item --export-manifest
  2900. Write to standard output a manifest suitable for @option{--manifest}
  2901. corresponding to the chosen profile(s).
  2902. This option is meant to help you migrate from the ``imperative''
  2903. operating mode---running @command{guix install}, @command{guix upgrade},
  2904. etc.---to the declarative mode that @option{--manifest} offers.
  2905. Be aware that the resulting manifest @emph{approximates} what your
  2906. profile actually contains; for instance, depending on how your profile
  2907. was created, it can refer to packages or package versions that are not
  2908. exactly what you specified.
  2909. Keep in mind that a manifest is purely symbolic: it only contains
  2910. package names and possibly versions, and their meaning varies over time.
  2911. If you wish to ``pin'' channels to the revisions that were used to build
  2912. the profile(s), see @option{--export-channels} below.
  2913. @cindex pinning, channel revisions of a profile
  2914. @item --export-channels
  2915. Write to standard output the list of channels used by the chosen
  2916. profile(s), in a format suitable for @command{guix pull --channels} or
  2917. @command{guix time-machine --channels} (@pxref{Channels}).
  2918. Together with @option{--export-manifest}, this option provides
  2919. information allowing you to replicate the current profile
  2920. (@pxref{Replicating Guix}).
  2921. However, note that the output of this command @emph{approximates} what
  2922. was actually used to build this profile. In particular, a single
  2923. profile might have been built from several different revisions of the
  2924. same channel. In that case, @option{--export-manifest} chooses the last
  2925. one and writes the list of other revisions in a comment. If you really
  2926. need to pick packages from different channel revisions, you can use
  2927. inferiors in your manifest to do so (@pxref{Inferiors}).
  2928. Together with @option{--export-manifest}, this is a good starting point
  2929. if you are willing to migrate from the ``imperative'' model to the fully
  2930. declarative model consisting of a manifest file along with a channels
  2931. file pinning the exact channel revision(s) you want.
  2932. @end table
  2933. Finally, since @command{guix package} may actually start build
  2934. processes, it supports all the common build options (@pxref{Common Build
  2935. Options}). It also supports package transformation options, such as
  2936. @option{--with-source}, and preserves them across upgrades
  2937. (@pxref{Package Transformation Options}).
  2938. @node Substitutes
  2939. @section Substitutes
  2940. @cindex substitutes
  2941. @cindex pre-built binaries
  2942. Guix supports transparent source/binary deployment, which means that it
  2943. can either build things locally, or download pre-built items from a
  2944. server, or both. We call these pre-built items @dfn{substitutes}---they
  2945. are substitutes for local build results. In many cases, downloading a
  2946. substitute is much faster than building things locally.
  2947. Substitutes can be anything resulting from a derivation build
  2948. (@pxref{Derivations}). Of course, in the common case, they are
  2949. pre-built package binaries, but source tarballs, for instance, which
  2950. also result from derivation builds, can be available as substitutes.
  2951. @menu
  2952. * Official Substitute Server:: One particular source of substitutes.
  2953. * Substitute Server Authorization:: How to enable or disable substitutes.
  2954. * Getting Substitutes from Other Servers:: Substitute diversity.
  2955. * Getting Substitutes from Other Protocols:: Different sources of substitutes.
  2956. * Substitute Authentication:: How Guix verifies substitutes.
  2957. * Proxy Settings:: How to get substitutes via proxy.
  2958. * Substitution Failure:: What happens when substitution fails.
  2959. * On Trusting Binaries:: How can you trust that binary blob?
  2960. @end menu
  2961. @node Official Substitute Server
  2962. @subsection Official Substitute Server
  2963. @cindex build farm
  2964. The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
  2965. that builds packages from Guix continuously for some
  2966. architectures, and makes them available as substitutes. This is the
  2967. default source of substitutes; it can be overridden by passing the
  2968. @option{--substitute-urls} option either to @command{guix-daemon}
  2969. (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
  2970. or to client tools such as @command{guix package}
  2971. (@pxref{client-substitute-urls,, client @option{--substitute-urls}
  2972. option}).
  2973. Substitute URLs can be either HTTP or HTTPS.
  2974. HTTPS is recommended because communications are encrypted; conversely,
  2975. using HTTP makes all communications visible to an eavesdropper, who
  2976. could use the information gathered to determine, for instance, whether
  2977. your system has unpatched security vulnerabilities.
  2978. Substitutes from the official build farm are enabled by default when
  2979. using Guix System (@pxref{GNU Distribution}). However,
  2980. they are disabled by default when using Guix on a foreign distribution,
  2981. unless you have explicitly enabled them via one of the recommended
  2982. installation steps (@pxref{Installation}). The following paragraphs
  2983. describe how to enable or disable substitutes for the official build
  2984. farm; the same procedure can also be used to enable substitutes for any
  2985. other substitute server.
  2986. @node Substitute Server Authorization
  2987. @subsection Substitute Server Authorization
  2988. @cindex security
  2989. @cindex substitutes, authorization thereof
  2990. @cindex access control list (ACL), for substitutes
  2991. @cindex ACL (access control list), for substitutes
  2992. To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
  2993. mirror thereof, you
  2994. must add its public key to the access control list (ACL) of archive
  2995. imports, using the @command{guix archive} command (@pxref{Invoking guix
  2996. archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
  2997. be compromised and to serve genuine substitutes.
  2998. @quotation Note
  2999. If you are using Guix System, you can skip this section: Guix System
  3000. authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
  3001. @end quotation
  3002. The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
  3003. @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
  3004. the installation prefix of Guix. If you installed Guix from source,
  3005. make sure you checked the GPG signature of
  3006. @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
  3007. Then, you can run something like this:
  3008. @example
  3009. # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
  3010. @end example
  3011. Once this is in place, the output of a command like @code{guix build}
  3012. should change from something like:
  3013. @example
  3014. $ guix build emacs --dry-run
  3015. The following derivations would be built:
  3016. /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
  3017. /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
  3018. /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
  3019. /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
  3020. @dots{}
  3021. @end example
  3022. @noindent
  3023. to something like:
  3024. @example
  3025. $ guix build emacs --dry-run
  3026. 112.3 MB would be downloaded:
  3027. /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
  3028. /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
  3029. /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
  3030. /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
  3031. @dots{}
  3032. @end example
  3033. @noindent
  3034. The text changed from ``The following derivations would be built'' to
  3035. ``112.3 MB would be downloaded''. This indicates that substitutes from
  3036. @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
  3037. possible, for future builds.
  3038. @cindex substitutes, how to disable
  3039. The substitute mechanism can be disabled globally by running
  3040. @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
  3041. guix-daemon}). It can also be disabled temporarily by passing the
  3042. @option{--no-substitutes} option to @command{guix package},
  3043. @command{guix build}, and other command-line tools.
  3044. @node Getting Substitutes from Other Servers
  3045. @subsection Getting Substitutes from Other Servers
  3046. @cindex substitute servers, adding more
  3047. Guix can look up and fetch substitutes from several servers. This is
  3048. useful when you are using packages from additional channels for which
  3049. the official server does not have substitutes but another server
  3050. provides them. Another situation where this is useful is when you would
  3051. prefer to download from your organization's substitute server, resorting
  3052. to the official server only as a fallback or dismissing it altogether.
  3053. You can give Guix a list of substitute server URLs and it will check
  3054. them in the specified order. You also need to explicitly authorize the
  3055. public keys of substitute servers to instruct Guix to accept the
  3056. substitutes they sign.
  3057. On Guix System, this is achieved by modifying the configuration of the
  3058. @code{guix} service. Since the @code{guix} service is part of the
  3059. default lists of services, @code{%base-services} and
  3060. @code{%desktop-services}, you can use @code{modify-services} to change
  3061. its configuration and add the URLs and substitute keys that you want
  3062. (@pxref{Service Reference, @code{modify-services}}).
  3063. As an example, suppose you want to fetch substitutes from
  3064. @code{guix.example.org} and to authorize the signing key of that server,
  3065. in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
  3066. resulting operating system configuration will look something like:
  3067. @lisp
  3068. (operating-system
  3069. ;; @dots{}
  3070. (services
  3071. ;; Assume we're starting from '%desktop-services'. Replace it
  3072. ;; with the list of services you're actually using.
  3073. (modify-services %desktop-services
  3074. (guix-service-type config =>
  3075. (guix-configuration
  3076. (inherit config)
  3077. (substitute-urls
  3078. (append (list "https://guix.example.org")
  3079. %default-substitute-urls))
  3080. (authorized-keys
  3081. (append (list (local-file "./key.pub"))
  3082. %default-authorized-guix-keys)))))))
  3083. @end lisp
  3084. This assumes that the file @file{key.pub} contains the signing key of
  3085. @code{guix.example.org}. With this change in place in your operating
  3086. system configuration file (say @file{/etc/config.scm}), you can
  3087. reconfigure and restart the @code{guix-daemon} service or reboot so the
  3088. changes take effect:
  3089. @example
  3090. $ sudo guix system reconfigure /etc/config.scm
  3091. $ sudo herd restart guix-daemon
  3092. @end example
  3093. If you're running Guix on a ``foreign distro'', you would instead take
  3094. the following steps to get substitutes from additional servers:
  3095. @enumerate
  3096. @item
  3097. Edit the service configuration file for @code{guix-daemon}; when using
  3098. systemd, this is normally
  3099. @file{/etc/systemd/system/guix-daemon.service}. Add the
  3100. @option{--substitute-urls} option on the @command{guix-daemon} command
  3101. line and list the URLs of interest (@pxref{daemon-substitute-urls,
  3102. @code{guix-daemon --substitute-urls}}):
  3103. @example
  3104. @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
  3105. @end example
  3106. @item
  3107. Restart the daemon. For systemd, it goes like this:
  3108. @example
  3109. systemctl daemon-reload
  3110. systemctl restart guix-daemon.service
  3111. @end example
  3112. @item
  3113. Authorize the key of the new server (@pxref{Invoking guix archive}):
  3114. @example
  3115. guix archive --authorize < key.pub
  3116. @end example
  3117. Again this assumes @file{key.pub} contains the public key that
  3118. @code{guix.example.org} uses to sign substitutes.
  3119. @end enumerate
  3120. Now you're all set! Substitutes will be preferably taken from
  3121. @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
  3122. as a fallback. Of course you can list as many substitute servers as you
  3123. like, with the caveat that substitute lookup can be slowed down if too
  3124. many servers need to be contacted.
  3125. Note that there are also situations where one may want to add the URL of
  3126. a substitute server @emph{without} authorizing its key.
  3127. @xref{Substitute Authentication}, to understand this fine point.
  3128. @node Getting Substitutes from Other Protocols
  3129. @subsection Getting Substitutes from Other Protocols
  3130. @cindex substitute servers, alternative protocols
  3131. This subsection probably won't make much sense yet,
  3132. as currently only the HTTP and HTTPS protocols are supported
  3133. for substitution. Consider what follows as a peek into the future!
  3134. Guix will support multiple substitution methods -- currently only
  3135. a substituter for HTTP and HTTPS is defined, but a substituter for
  3136. the P2P networks IPFS and GNUnet will be defined in the future.
  3137. @c The IPFS substituter has actually already been implemented,
  3138. @c see http://issues.guix.gnu.org/33899, but it requires some changes
  3139. @c and is not yet available to the end-user.
  3140. In order to use a substition method, it must first be enabled in the
  3141. guix daemon
  3142. (@pxref{Invoking guix-daemon, @option{--substitute-methods}}).
  3143. For example, to enable the HTTP/S and the yet-to-be-written IPFS
  3144. substituter, pass @code{--substitute-methods='http ipfs'}.
  3145. This must be set in the daemon, and cannot be done from a user process.
  3146. @c XXX ^ is this sentence clear? I mean ``guix build --substitute-methods``
  3147. @c won't work, as substitution happens in the daemon (well, in a process
  3148. @c started by the daemon to be precise).
  3149. Also include an URL supported by the substituter in the list of
  3150. substitute server URLs. That's all there is to it!
  3151. @c TODO ^ when using the IPFS substituter, the daemon also needs -
  3152. @c to know the IPFS gateway, and when using the GNUnet substituter,
  3153. @c GNUnet needs to be running. But let's first actually implement
  3154. @c & merge these substituters ...
  3155. @node Substitute Authentication
  3156. @subsection Substitute Authentication
  3157. @cindex digital signatures
  3158. Guix detects and raises an error when attempting to use a substitute
  3159. that has been tampered with. Likewise, it ignores substitutes that are
  3160. not signed, or that are not signed by one of the keys listed in the ACL.
  3161. There is one exception though: if an unauthorized server provides
  3162. substitutes that are @emph{bit-for-bit identical} to those provided by
  3163. an authorized server, then the unauthorized server becomes eligible for
  3164. downloads. For example, assume we have chosen two substitute servers
  3165. with this option:
  3166. @example
  3167. --substitute-urls="https://a.example.org https://b.example.org"
  3168. @end example
  3169. @noindent
  3170. @cindex reproducible builds
  3171. If the ACL contains only the key for @samp{b.example.org}, and if
  3172. @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
  3173. then Guix will download substitutes from @samp{a.example.org} because it
  3174. comes first in the list and can be considered a mirror of
  3175. @samp{b.example.org}. In practice, independent build machines usually
  3176. produce the same binaries, thanks to bit-reproducible builds (see
  3177. below).
  3178. When using HTTPS, the server's X.509 certificate is @emph{not} validated
  3179. (in other words, the server is not authenticated), contrary to what
  3180. HTTPS clients such as Web browsers usually do. This is because Guix
  3181. authenticates substitute information itself, as explained above, which
  3182. is what we care about (whereas X.509 certificates are about
  3183. authenticating bindings between domain names and public keys).
  3184. @node Proxy Settings
  3185. @subsection Proxy Settings
  3186. @vindex http_proxy
  3187. @vindex https_proxy
  3188. Substitutes are downloaded over HTTP or HTTPS@. The @env{http_proxy} and
  3189. @env{https_proxy} environment variables can be set in the environment of
  3190. @command{guix-daemon} and are honored for downloads of substitutes.
  3191. Note that the value of those environment variables in the environment
  3192. where @command{guix build}, @command{guix package}, and other client
  3193. commands are run has @emph{absolutely no effect}.
  3194. @node Substitution Failure
  3195. @subsection Substitution Failure
  3196. Even when a substitute for a derivation is available, sometimes the
  3197. substitution attempt will fail. This can happen for a variety of
  3198. reasons: the substitute server might be offline, the substitute may
  3199. recently have been deleted, the connection might have been interrupted,
  3200. etc.
  3201. When substitutes are enabled and a substitute for a derivation is
  3202. available, but the substitution attempt fails, Guix will attempt to
  3203. build the derivation locally depending on whether or not
  3204. @option{--fallback} was given (@pxref{fallback-option,, common build
  3205. option @option{--fallback}}). Specifically, if @option{--fallback} was
  3206. omitted, then no local build will be performed, and the derivation is
  3207. considered to have failed. However, if @option{--fallback} was given,
  3208. then Guix will attempt to build the derivation locally, and the success
  3209. or failure of the derivation depends on the success or failure of the
  3210. local build. Note that when substitutes are disabled or no substitute
  3211. is available for the derivation in question, a local build will
  3212. @emph{always} be performed, regardless of whether or not
  3213. @option{--fallback} was given.
  3214. To get an idea of how many substitutes are available right now, you can
  3215. try running the @command{guix weather} command (@pxref{Invoking guix
  3216. weather}). This command provides statistics on the substitutes provided
  3217. by a server.
  3218. @node On Trusting Binaries
  3219. @subsection On Trusting Binaries
  3220. @cindex trust, of pre-built binaries
  3221. Today, each individual's control over their own computing is at the
  3222. mercy of institutions, corporations, and groups with enough power and
  3223. determination to subvert the computing infrastructure and exploit its
  3224. weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
  3225. convenient, we encourage users to also build on their own, or even run
  3226. their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
  3227. interesting target. One way to help is by publishing the software you
  3228. build using @command{guix publish} so that others have one more choice
  3229. of server to download substitutes from (@pxref{Invoking guix publish}).
  3230. Guix has the foundations to maximize build reproducibility
  3231. (@pxref{Features}). In most cases, independent builds of a given
  3232. package or derivation should yield bit-identical results. Thus, through
  3233. a diverse set of independent package builds, we can strengthen the
  3234. integrity of our systems. The @command{guix challenge} command aims to
  3235. help users assess substitute servers, and to assist developers in
  3236. finding out about non-deterministic package builds (@pxref{Invoking guix
  3237. challenge}). Similarly, the @option{--check} option of @command{guix
  3238. build} allows users to check whether previously-installed substitutes
  3239. are genuine by rebuilding them locally (@pxref{build-check,
  3240. @command{guix build --check}}).
  3241. In the future, we want Guix to have support to publish and retrieve
  3242. binaries to/from other users, in a peer-to-peer fashion. If you would
  3243. like to discuss this project, join us on @email{guix-devel@@gnu.org}.
  3244. @node Packages with Multiple Outputs
  3245. @section Packages with Multiple Outputs
  3246. @cindex multiple-output packages
  3247. @cindex package outputs
  3248. @cindex outputs
  3249. Often, packages defined in Guix have a single @dfn{output}---i.e., the
  3250. source package leads to exactly one directory in the store. When running
  3251. @command{guix install glibc}, one installs the default output of the
  3252. GNU libc package; the default output is called @code{out}, but its name
  3253. can be omitted as shown in this command. In this particular case, the
  3254. default output of @code{glibc} contains all the C header files, shared
  3255. libraries, static libraries, Info documentation, and other supporting
  3256. files.
  3257. Sometimes it is more appropriate to separate the various types of files
  3258. produced from a single source package into separate outputs. For
  3259. instance, the GLib C library (used by GTK+ and related packages)
  3260. installs more than 20 MiB of reference documentation as HTML pages.
  3261. To save space for users who do not need it, the documentation goes to a
  3262. separate output, called @code{doc}. To install the main GLib output,
  3263. which contains everything but the documentation, one would run:
  3264. @example
  3265. guix install glib
  3266. @end example
  3267. @cindex documentation
  3268. The command to install its documentation is:
  3269. @example
  3270. guix install glib:doc
  3271. @end example
  3272. Some packages install programs with different ``dependency footprints''.
  3273. For instance, the WordNet package installs both command-line tools and
  3274. graphical user interfaces (GUIs). The former depend solely on the C
  3275. library, whereas the latter depend on Tcl/Tk and the underlying X
  3276. libraries. In this case, we leave the command-line tools in the default
  3277. output, whereas the GUIs are in a separate output. This allows users
  3278. who do not need the GUIs to save space. The @command{guix size} command
  3279. can help find out about such situations (@pxref{Invoking guix size}).
  3280. @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
  3281. There are several such multiple-output packages in the GNU distribution.
  3282. Other conventional output names include @code{lib} for libraries and
  3283. possibly header files, @code{bin} for stand-alone programs, and
  3284. @code{debug} for debugging information (@pxref{Installing Debugging
  3285. Files}). The outputs of a packages are listed in the third column of
  3286. the output of @command{guix package --list-available} (@pxref{Invoking
  3287. guix package}).
  3288. @node Invoking guix gc
  3289. @section Invoking @command{guix gc}
  3290. @cindex garbage collector
  3291. @cindex disk space
  3292. Packages that are installed, but not used, may be @dfn{garbage-collected}.
  3293. The @command{guix gc} command allows users to explicitly run the garbage
  3294. collector to reclaim space from the @file{/gnu/store} directory. It is
  3295. the @emph{only} way to remove files from @file{/gnu/store}---removing
  3296. files or directories manually may break it beyond repair!
  3297. @cindex GC roots
  3298. @cindex garbage collector roots
  3299. The garbage collector has a set of known @dfn{roots}: any file under
  3300. @file{/gnu/store} reachable from a root is considered @dfn{live} and
  3301. cannot be deleted; any other file is considered @dfn{dead} and may be
  3302. deleted. The set of garbage collector roots (``GC roots'' for short)
  3303. includes default user profiles; by default, the symlinks under
  3304. @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
  3305. added with @command{guix build --root}, for example (@pxref{Invoking
  3306. guix build}). The @command{guix gc --list-roots} command lists them.
  3307. Prior to running @code{guix gc --collect-garbage} to make space, it is
  3308. often useful to remove old generations from user profiles; that way, old
  3309. package builds referenced by those generations can be reclaimed. This
  3310. is achieved by running @code{guix package --delete-generations}
  3311. (@pxref{Invoking guix package}).
  3312. Our recommendation is to run a garbage collection periodically, or when
  3313. you are short on disk space. For instance, to guarantee that at least
  3314. 5@tie{}GB are available on your disk, simply run:
  3315. @example
  3316. guix gc -F 5G
  3317. @end example
  3318. It is perfectly safe to run as a non-interactive periodic job
  3319. (@pxref{Scheduled Job Execution}, for how to set up such a job).
  3320. Running @command{guix gc} with no arguments will collect as
  3321. much garbage as it can, but that is often inconvenient: you may find
  3322. yourself having to rebuild or re-download software that is ``dead'' from
  3323. the GC viewpoint but that is necessary to build other pieces of
  3324. software---e.g., the compiler tool chain.
  3325. The @command{guix gc} command has three modes of operation: it can be
  3326. used to garbage-collect any dead files (the default), to delete specific
  3327. files (the @option{--delete} option), to print garbage-collector
  3328. information, or for more advanced queries. The garbage collection
  3329. options are as follows:
  3330. @table @code
  3331. @item --collect-garbage[=@var{min}]
  3332. @itemx -C [@var{min}]
  3333. Collect garbage---i.e., unreachable @file{/gnu/store} files and
  3334. sub-directories. This is the default operation when no option is
  3335. specified.
  3336. When @var{min} is given, stop once @var{min} bytes have been collected.
  3337. @var{min} may be a number of bytes, or it may include a unit as a
  3338. suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
  3339. (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
  3340. When @var{min} is omitted, collect all the garbage.
  3341. @item --free-space=@var{free}
  3342. @itemx -F @var{free}
  3343. Collect garbage until @var{free} space is available under
  3344. @file{/gnu/store}, if possible; @var{free} denotes storage space, such
  3345. as @code{500MiB}, as described above.
  3346. When @var{free} or more is already available in @file{/gnu/store}, do
  3347. nothing and exit immediately.
  3348. @item --delete-generations[=@var{duration}]
  3349. @itemx -d [@var{duration}]
  3350. Before starting the garbage collection process, delete all the generations
  3351. older than @var{duration}, for all the user profiles; when run as root, this
  3352. applies to all the profiles @emph{of all the users}.
  3353. For example, this command deletes all the generations of all your profiles
  3354. that are older than 2 months (except generations that are current), and then
  3355. proceeds to free space until at least 10 GiB are available:
  3356. @example
  3357. guix gc -d 2m -F 10G
  3358. @end example
  3359. @item --delete
  3360. @itemx -D
  3361. Attempt to delete all the store files and directories specified as
  3362. arguments. This fails if some of the files are not in the store, or if
  3363. they are still live.
  3364. @item --list-failures
  3365. List store items corresponding to cached build failures.
  3366. This prints nothing unless the daemon was started with
  3367. @option{--cache-failures} (@pxref{Invoking guix-daemon,
  3368. @option{--cache-failures}}).
  3369. @item --list-roots
  3370. List the GC roots owned by the user; when run as root, list @emph{all} the GC
  3371. roots.
  3372. @item --list-busy
  3373. List store items in use by currently running processes. These store
  3374. items are effectively considered GC roots: they cannot be deleted.
  3375. @item --clear-failures
  3376. Remove the specified store items from the failed-build cache.
  3377. Again, this option only makes sense when the daemon is started with
  3378. @option{--cache-failures}. Otherwise, it does nothing.
  3379. @item --list-dead
  3380. Show the list of dead files and directories still present in the
  3381. store---i.e., files and directories no longer reachable from any root.
  3382. @item --list-live
  3383. Show the list of live store files and directories.
  3384. @end table
  3385. In addition, the references among existing store files can be queried:
  3386. @table @code
  3387. @item --references
  3388. @itemx --referrers
  3389. @cindex package dependencies
  3390. List the references (respectively, the referrers) of store files given
  3391. as arguments.
  3392. @item --requisites
  3393. @itemx -R
  3394. @cindex closure
  3395. List the requisites of the store files passed as arguments. Requisites
  3396. include the store files themselves, their references, and the references
  3397. of these, recursively. In other words, the returned list is the
  3398. @dfn{transitive closure} of the store files.
  3399. @xref{Invoking guix size}, for a tool to profile the size of the closure
  3400. of an element. @xref{Invoking guix graph}, for a tool to visualize
  3401. the graph of references.
  3402. @item --derivers
  3403. @cindex derivation
  3404. Return the derivation(s) leading to the given store items
  3405. (@pxref{Derivations}).
  3406. For example, this command:
  3407. @example
  3408. guix gc --derivers `guix package -I ^emacs$ | cut -f4`
  3409. @end example
  3410. @noindent
  3411. returns the @file{.drv} file(s) leading to the @code{emacs} package
  3412. installed in your profile.
  3413. Note that there may be zero matching @file{.drv} files, for instance
  3414. because these files have been garbage-collected. There can also be more
  3415. than one matching @file{.drv} due to fixed-output derivations.
  3416. @end table
  3417. Lastly, the following options allow you to check the integrity of the
  3418. store and to control disk usage.
  3419. @table @option
  3420. @item --verify[=@var{options}]
  3421. @cindex integrity, of the store
  3422. @cindex integrity checking
  3423. Verify the integrity of the store.
  3424. By default, make sure that all the store items marked as valid in the
  3425. database of the daemon actually exist in @file{/gnu/store}.
  3426. When provided, @var{options} must be a comma-separated list containing one
  3427. or more of @code{contents} and @code{repair}.
  3428. When passing @option{--verify=contents}, the daemon computes the
  3429. content hash of each store item and compares it against its hash in the
  3430. database. Hash mismatches are reported as data corruptions. Because it
  3431. traverses @emph{all the files in the store}, this command can take a
  3432. long time, especially on systems with a slow disk drive.
  3433. @cindex repairing the store
  3434. @cindex corruption, recovering from
  3435. Using @option{--verify=repair} or @option{--verify=contents,repair}
  3436. causes the daemon to try to repair corrupt store items by fetching
  3437. substitutes for them (@pxref{Substitutes}). Because repairing is not
  3438. atomic, and thus potentially dangerous, it is available only to the
  3439. system administrator. A lightweight alternative, when you know exactly
  3440. which items in the store are corrupt, is @command{guix build --repair}
  3441. (@pxref{Invoking guix build}).
  3442. @item --optimize
  3443. @cindex deduplication
  3444. Optimize the store by hard-linking identical files---this is
  3445. @dfn{deduplication}.
  3446. The daemon performs deduplication after each successful build or archive
  3447. import, unless it was started with @option{--disable-deduplication}
  3448. (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
  3449. this option is primarily useful when the daemon was running with
  3450. @option{--disable-deduplication}.
  3451. @end table
  3452. @node Invoking guix pull
  3453. @section Invoking @command{guix pull}
  3454. @cindex upgrading Guix
  3455. @cindex updating Guix
  3456. @cindex @command{guix pull}
  3457. @cindex pull
  3458. @cindex security, @command{guix pull}
  3459. @cindex authenticity, of code obtained with @command{guix pull}
  3460. Packages are installed or upgraded to the latest version available in
  3461. the distribution currently available on your local machine. To update
  3462. that distribution, along with the Guix tools, you must run @command{guix
  3463. pull}: the command downloads the latest Guix source code and package
  3464. descriptions, and deploys it. Source code is downloaded from a
  3465. @uref{https://git-scm.com, Git} repository, by default the official
  3466. GNU@tie{}Guix repository, though this can be customized. @command{guix
  3467. pull} ensures that the code it downloads is @emph{authentic} by
  3468. verifying that commits are signed by Guix developers.
  3469. Specifically, @command{guix pull} downloads code from the @dfn{channels}
  3470. (@pxref{Channels}) specified by one of the followings, in this order:
  3471. @enumerate
  3472. @item
  3473. the @option{--channels} option;
  3474. @item
  3475. the user's @file{~/.config/guix/channels.scm} file;
  3476. @item
  3477. the system-wide @file{/etc/guix/channels.scm} file;
  3478. @item
  3479. the built-in default channels specified in the @code{%default-channels}
  3480. variable.
  3481. @end enumerate
  3482. On completion, @command{guix package} will use packages and package
  3483. versions from this just-retrieved copy of Guix. Not only that, but all
  3484. the Guix commands and Scheme modules will also be taken from that latest
  3485. version. New @command{guix} sub-commands added by the update also
  3486. become available.
  3487. Any user can update their Guix copy using @command{guix pull}, and the
  3488. effect is limited to the user who ran @command{guix pull}. For
  3489. instance, when user @code{root} runs @command{guix pull}, this has no
  3490. effect on the version of Guix that user @code{alice} sees, and vice
  3491. versa.
  3492. The result of running @command{guix pull} is a @dfn{profile} available
  3493. under @file{~/.config/guix/current} containing the latest Guix. Thus,
  3494. make sure to add it to the beginning of your search path so that you use
  3495. the latest version, and similarly for the Info manual
  3496. (@pxref{Documentation}):
  3497. @example
  3498. export PATH="$HOME/.config/guix/current/bin:$PATH"
  3499. export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
  3500. @end example
  3501. The @option{--list-generations} or @option{-l} option lists past generations
  3502. produced by @command{guix pull}, along with details about their provenance:
  3503. @example
  3504. $ guix pull -l
  3505. Generation 1 Jun 10 2018 00:18:18
  3506. guix 65956ad
  3507. repository URL: https://git.savannah.gnu.org/git/guix.git
  3508. branch: origin/master
  3509. commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
  3510. Generation 2 Jun 11 2018 11:02:49
  3511. guix e0cc7f6
  3512. repository URL: https://git.savannah.gnu.org/git/guix.git
  3513. branch: origin/master
  3514. commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
  3515. 2 new packages: keepalived, libnfnetlink
  3516. 6 packages upgraded: emacs-nix-mode@@2.0.4,
  3517. guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
  3518. heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
  3519. Generation 3 Jun 13 2018 23:31:07 (current)
  3520. guix 844cc1c
  3521. repository URL: https://git.savannah.gnu.org/git/guix.git
  3522. branch: origin/master
  3523. commit: 844cc1c8f394f03b404c5bb3aee086922373490c
  3524. 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
  3525. 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
  3526. @end example
  3527. @xref{Invoking guix describe, @command{guix describe}}, for other ways to
  3528. describe the current status of Guix.
  3529. This @code{~/.config/guix/current} profile works exactly like the profiles
  3530. created by @command{guix package} (@pxref{Invoking guix package}). That
  3531. is, you can list generations, roll back to the previous
  3532. generation---i.e., the previous Guix---and so on:
  3533. @example
  3534. $ guix pull --roll-back
  3535. switched from generation 3 to 2
  3536. $ guix pull --delete-generations=1
  3537. deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
  3538. @end example
  3539. You can also use @command{guix package} (@pxref{Invoking guix package})
  3540. to manage the profile by naming it explicitly:
  3541. @example
  3542. $ guix package -p ~/.config/guix/current --roll-back
  3543. switched from generation 3 to 2
  3544. $ guix package -p ~/.config/guix/current --delete-generations=1
  3545. deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
  3546. @end example
  3547. The @command{guix pull} command is usually invoked with no arguments,
  3548. but it supports the following options:
  3549. @table @code
  3550. @item --url=@var{url}
  3551. @itemx --commit=@var{commit}
  3552. @itemx --branch=@var{branch}
  3553. Download code for the @code{guix} channel from the specified @var{url}, at the
  3554. given @var{commit} (a valid Git commit ID represented as a hexadecimal
  3555. string), or @var{branch}.
  3556. @cindex @file{channels.scm}, configuration file
  3557. @cindex configuration file for channels
  3558. These options are provided for convenience, but you can also specify your
  3559. configuration in the @file{~/.config/guix/channels.scm} file or using the
  3560. @option{--channels} option (see below).
  3561. @item --channels=@var{file}
  3562. @itemx -C @var{file}
  3563. Read the list of channels from @var{file} instead of
  3564. @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
  3565. @var{file} must contain Scheme code that
  3566. evaluates to a list of channel objects. @xref{Channels}, for more
  3567. information.
  3568. @cindex channel news
  3569. @item --news
  3570. @itemx -N
  3571. Display the list of packages added or upgraded since the previous
  3572. generation, as well as, occasionally, news written by channel authors
  3573. for their users (@pxref{Channels, Writing Channel News}).
  3574. The package information is the same as displayed upon @command{guix
  3575. pull} completion, but without ellipses; it is also similar to the output
  3576. of @command{guix pull -l} for the last generation (see below).
  3577. @item --list-generations[=@var{pattern}]
  3578. @itemx -l [@var{pattern}]
  3579. List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
  3580. is provided, the subset of generations that match @var{pattern}.
  3581. The syntax of @var{pattern} is the same as with @code{guix package
  3582. --list-generations} (@pxref{Invoking guix package}).
  3583. @item --roll-back
  3584. @cindex rolling back
  3585. @cindex undoing transactions
  3586. @cindex transactions, undoing
  3587. Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
  3588. undo the last transaction.
  3589. @item --switch-generation=@var{pattern}
  3590. @itemx -S @var{pattern}
  3591. @cindex generations
  3592. Switch to a particular generation defined by @var{pattern}.
  3593. @var{pattern} may be either a generation number or a number prefixed
  3594. with ``+'' or ``-''. The latter means: move forward/backward by a
  3595. specified number of generations. For example, if you want to return to
  3596. the latest generation after @option{--roll-back}, use
  3597. @option{--switch-generation=+1}.
  3598. @item --delete-generations[=@var{pattern}]
  3599. @itemx -d [@var{pattern}]
  3600. When @var{pattern} is omitted, delete all generations except the current
  3601. one.
  3602. This command accepts the same patterns as @option{--list-generations}.
  3603. When @var{pattern} is specified, delete the matching generations. When
  3604. @var{pattern} specifies a duration, generations @emph{older} than the
  3605. specified duration match. For instance, @option{--delete-generations=1m}
  3606. deletes generations that are more than one month old.
  3607. If the current generation matches, it is @emph{not} deleted.
  3608. Note that deleting generations prevents rolling back to them.
  3609. Consequently, this command must be used with care.
  3610. @xref{Invoking guix describe}, for a way to display information about the
  3611. current generation only.
  3612. @item --profile=@var{profile}
  3613. @itemx -p @var{profile}
  3614. Use @var{profile} instead of @file{~/.config/guix/current}.
  3615. @item --dry-run
  3616. @itemx -n
  3617. Show which channel commit(s) would be used and what would be built or
  3618. substituted but do not actually do it.
  3619. @item --allow-downgrades
  3620. Allow pulling older or unrelated revisions of channels than those
  3621. currently in use.
  3622. @cindex downgrade attacks, protection against
  3623. By default, @command{guix pull} protects against so-called ``downgrade
  3624. attacks'' whereby the Git repository of a channel would be reset to an
  3625. earlier or unrelated revision of itself, potentially leading you to
  3626. install older, known-vulnerable versions of software packages.
  3627. @quotation Note
  3628. Make sure you understand its security implications before using
  3629. @option{--allow-downgrades}.
  3630. @end quotation
  3631. @item --disable-authentication
  3632. Allow pulling channel code without authenticating it.
  3633. @cindex authentication, of channel code
  3634. By default, @command{guix pull} authenticates code downloaded from
  3635. channels by verifying that its commits are signed by authorized
  3636. developers, and raises an error if this is not the case. This option
  3637. instructs it to not perform any such verification.
  3638. @quotation Note
  3639. Make sure you understand its security implications before using
  3640. @option{--disable-authentication}.
  3641. @end quotation
  3642. @item --system=@var{system}
  3643. @itemx -s @var{system}
  3644. Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
  3645. the system type of the build host.
  3646. @item --bootstrap
  3647. Use the bootstrap Guile to build the latest Guix. This option is only
  3648. useful to Guix developers.
  3649. @end table
  3650. The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
  3651. repository and branch to pull from, as well as @emph{additional} repositories
  3652. containing package modules that should be deployed. @xref{Channels}, for more
  3653. information.
  3654. In addition, @command{guix pull} supports all the common build options
  3655. (@pxref{Common Build Options}).
  3656. @node Invoking guix time-machine
  3657. @section Invoking @command{guix time-machine}
  3658. @cindex @command{guix time-machine}
  3659. @cindex pinning, channels
  3660. @cindex replicating Guix
  3661. @cindex reproducibility, of Guix
  3662. The @command{guix time-machine} command provides access to other
  3663. revisions of Guix, for example to install older versions of packages,
  3664. or to reproduce a computation in an identical environment. The revision
  3665. of Guix to be used is defined by a commit or by a channel
  3666. description file created by @command{guix describe}
  3667. (@pxref{Invoking guix describe}).
  3668. The general syntax is:
  3669. @example
  3670. guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
  3671. @end example
  3672. where @var{command} and @var{arg}@dots{} are passed unmodified to the
  3673. @command{guix} command of the specified revision. The @var{options} that define
  3674. this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
  3675. @table @code
  3676. @item --url=@var{url}
  3677. @itemx --commit=@var{commit}
  3678. @itemx --branch=@var{branch}
  3679. Use the @code{guix} channel from the specified @var{url}, at the
  3680. given @var{commit} (a valid Git commit ID represented as a hexadecimal
  3681. string), or @var{branch}.
  3682. @item --channels=@var{file}
  3683. @itemx -C @var{file}
  3684. Read the list of channels from @var{file}. @var{file} must contain
  3685. Scheme code that evaluates to a list of channel objects.
  3686. @xref{Channels} for more information.
  3687. @end table
  3688. As for @command{guix pull}, the absence of any options means that the
  3689. latest commit on the master branch will be used. The command
  3690. @example
  3691. guix time-machine -- build hello
  3692. @end example
  3693. will thus build the package @code{hello} as defined in the master branch,
  3694. which is in general a newer revision of Guix than you have installed.
  3695. Time travel works in both directions!
  3696. Note that @command{guix time-machine} can trigger builds of channels and
  3697. their dependencies, and these are controlled by the standard build
  3698. options (@pxref{Common Build Options}).
  3699. @node Inferiors
  3700. @section Inferiors
  3701. @c TODO: Remove this once we're more confident about API stability.
  3702. @quotation Note
  3703. The functionality described here is a ``technology preview'' as of version
  3704. @value{VERSION}. As such, the interface is subject to change.
  3705. @end quotation
  3706. @cindex inferiors
  3707. @cindex composition of Guix revisions
  3708. Sometimes you might need to mix packages from the revision of Guix you're
  3709. currently running with packages available in a different revision of Guix.
  3710. Guix @dfn{inferiors} allow you to achieve that by composing different Guix
  3711. revisions in arbitrary ways.
  3712. @cindex inferior packages
  3713. Technically, an ``inferior'' is essentially a separate Guix process connected
  3714. to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
  3715. @code{(guix inferior)} module allows you to create inferiors and to
  3716. communicate with them. It also provides a high-level interface to browse and
  3717. manipulate the packages that an inferior provides---@dfn{inferior packages}.
  3718. When combined with channels (@pxref{Channels}), inferiors provide a simple way
  3719. to interact with a separate revision of Guix. For example, let's assume you
  3720. want to install in your profile the current @code{guile} package, along with
  3721. the @code{guile-json} as it existed in an older revision of Guix---perhaps
  3722. because the newer @code{guile-json} has an incompatible API and you want to
  3723. run your code against the old API@. To do that, you could write a manifest for
  3724. use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
  3725. manifest, you would create an inferior for that old Guix revision you care
  3726. about, and you would look up the @code{guile-json} package in the inferior:
  3727. @lisp
  3728. (use-modules (guix inferior) (guix channels)
  3729. (srfi srfi-1)) ;for 'first'
  3730. (define channels
  3731. ;; This is the old revision from which we want to
  3732. ;; extract guile-json.
  3733. (list (channel
  3734. (name 'guix)
  3735. (url "https://git.savannah.gnu.org/git/guix.git")
  3736. (commit
  3737. "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
  3738. (define inferior
  3739. ;; An inferior representing the above revision.
  3740. (inferior-for-channels channels))
  3741. ;; Now create a manifest with the current "guile" package
  3742. ;; and the old "guile-json" package.
  3743. (packages->manifest
  3744. (list (first (lookup-inferior-packages inferior "guile-json"))
  3745. (specification->package "guile")))
  3746. @end lisp
  3747. On its first run, @command{guix package --manifest} might have to build the
  3748. channel you specified before it can create the inferior; subsequent runs will
  3749. be much faster because the Guix revision will be cached.
  3750. The @code{(guix inferior)} module provides the following procedures to open an
  3751. inferior:
  3752. @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
  3753. [#:cache-directory] [#:ttl]
  3754. Return an inferior for @var{channels}, a list of channels. Use the cache at
  3755. @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
  3756. This procedure opens a new connection to the build daemon.
  3757. As a side effect, this procedure may build or substitute binaries for
  3758. @var{channels}, which can take time.
  3759. @end deffn
  3760. @deffn {Scheme Procedure} open-inferior @var{directory} @
  3761. [#:command "bin/guix"]
  3762. Open the inferior Guix in @var{directory}, running
  3763. @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
  3764. the inferior could not be launched.
  3765. @end deffn
  3766. @cindex inferior packages
  3767. The procedures listed below allow you to obtain and manipulate inferior
  3768. packages.
  3769. @deffn {Scheme Procedure} inferior-packages @var{inferior}
  3770. Return the list of packages known to @var{inferior}.
  3771. @end deffn
  3772. @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
  3773. [@var{version}]
  3774. Return the sorted list of inferior packages matching @var{name} in
  3775. @var{inferior}, with highest version numbers first. If @var{version} is true,
  3776. return only packages with a version number prefixed by @var{version}.
  3777. @end deffn
  3778. @deffn {Scheme Procedure} inferior-package? @var{obj}
  3779. Return true if @var{obj} is an inferior package.
  3780. @end deffn
  3781. @deffn {Scheme Procedure} inferior-package-name @var{package}
  3782. @deffnx {Scheme Procedure} inferior-package-version @var{package}
  3783. @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
  3784. @deffnx {Scheme Procedure} inferior-package-description @var{package}
  3785. @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
  3786. @deffnx {Scheme Procedure} inferior-package-location @var{package}
  3787. @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
  3788. @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
  3789. @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
  3790. @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
  3791. @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
  3792. @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
  3793. @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
  3794. These procedures are the counterpart of package record accessors
  3795. (@pxref{package Reference}). Most of them work by querying the inferior
  3796. @var{package} comes from, so the inferior must still be live when you call
  3797. these procedures.
  3798. @end deffn
  3799. Inferior packages can be used transparently like any other package or
  3800. file-like object in G-expressions (@pxref{G-Expressions}). They are also
  3801. transparently handled by the @code{packages->manifest} procedure, which is
  3802. commonly use in manifests (@pxref{Invoking guix package, the
  3803. @option{--manifest} option of @command{guix package}}). Thus you can insert
  3804. an inferior package pretty much anywhere you would insert a regular package:
  3805. in manifests, in the @code{packages} field of your @code{operating-system}
  3806. declaration, and so on.
  3807. @node Invoking guix describe
  3808. @section Invoking @command{guix describe}
  3809. @cindex reproducibility
  3810. @cindex replicating Guix
  3811. Often you may want to answer questions like: ``Which revision of Guix am I
  3812. using?'' or ``Which channels am I using?'' This is useful information in many
  3813. situations: if you want to @emph{replicate} an environment on a different
  3814. machine or user account, if you want to report a bug or to determine what
  3815. change in the channels you are using caused it, or if you want to record your
  3816. system state for reproducibility purposes. The @command{guix describe}
  3817. command answers these questions.
  3818. When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
  3819. displays the channel(s) that it was built from, including their repository URL
  3820. and commit IDs (@pxref{Channels}):
  3821. @example
  3822. $ guix describe
  3823. Generation 10 Sep 03 2018 17:32:44 (current)
  3824. guix e0fa68c
  3825. repository URL: https://git.savannah.gnu.org/git/guix.git
  3826. branch: master
  3827. commit: e0fa68c7718fffd33d81af415279d6ddb518f727
  3828. @end example
  3829. If you're familiar with the Git version control system, this is similar in
  3830. spirit to @command{git describe}; the output is also similar to that of
  3831. @command{guix pull --list-generations}, but limited to the current generation
  3832. (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
  3833. the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
  3834. information is all it takes to describe the revision of Guix you're using, and
  3835. also to replicate it.
  3836. To make it easier to replicate Guix, @command{guix describe} can also be asked
  3837. to return a list of channels instead of the human-readable description above:
  3838. @example
  3839. $ guix describe -f channels
  3840. (list (channel
  3841. (name 'guix)
  3842. (url "https://git.savannah.gnu.org/git/guix.git")
  3843. (commit
  3844. "e0fa68c7718fffd33d81af415279d6ddb518f727")
  3845. (introduction
  3846. (make-channel-introduction
  3847. "9edb3f66fd807b096b48283debdcddccfea34bad"
  3848. (openpgp-fingerprint
  3849. "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
  3850. @end example
  3851. @noindent
  3852. You can save this to a file and feed it to @command{guix pull -C} on some
  3853. other machine or at a later point in time, which will instantiate @emph{this
  3854. exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
  3855. From there on, since you're able to deploy the same revision of Guix, you can
  3856. just as well @emph{replicate a complete software environment}. We humbly
  3857. think that this is @emph{awesome}, and we hope you'll like it too!
  3858. The details of the options supported by @command{guix describe} are as
  3859. follows:
  3860. @table @code
  3861. @item --format=@var{format}
  3862. @itemx -f @var{format}
  3863. Produce output in the specified @var{format}, one of:
  3864. @table @code
  3865. @item human
  3866. produce human-readable output;
  3867. @item channels
  3868. produce a list of channel specifications that can be passed to @command{guix
  3869. pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
  3870. guix pull});
  3871. @item channels-sans-intro
  3872. like @code{channels}, but omit the @code{introduction} field; use it to
  3873. produce a channel specification suitable for Guix version 1.1.0 or
  3874. earlier---the @code{introduction} field has to do with channel
  3875. authentication (@pxref{Channels, Channel Authentication}) and is not
  3876. supported by these older versions;
  3877. @item json
  3878. @cindex JSON
  3879. produce a list of channel specifications in JSON format;
  3880. @item recutils
  3881. produce a list of channel specifications in Recutils format.
  3882. @end table
  3883. @item --list-formats
  3884. Display available formats for @option{--format} option.
  3885. @item --profile=@var{profile}
  3886. @itemx -p @var{profile}
  3887. Display information about @var{profile}.
  3888. @end table
  3889. @node Invoking guix archive
  3890. @section Invoking @command{guix archive}
  3891. @cindex @command{guix archive}
  3892. @cindex archive
  3893. The @command{guix archive} command allows users to @dfn{export} files
  3894. from the store into a single archive, and to later @dfn{import} them on
  3895. a machine that runs Guix.
  3896. In particular, it allows store files to be transferred from one machine
  3897. to the store on another machine.
  3898. @quotation Note
  3899. If you're looking for a way to produce archives in a format suitable for
  3900. tools other than Guix, @pxref{Invoking guix pack}.
  3901. @end quotation
  3902. @cindex exporting store items
  3903. To export store files as an archive to standard output, run:
  3904. @example
  3905. guix archive --export @var{options} @var{specifications}...
  3906. @end example
  3907. @var{specifications} may be either store file names or package
  3908. specifications, as for @command{guix package} (@pxref{Invoking guix
  3909. package}). For instance, the following command creates an archive
  3910. containing the @code{gui} output of the @code{git} package and the main
  3911. output of @code{emacs}:
  3912. @example
  3913. guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
  3914. @end example
  3915. If the specified packages are not built yet, @command{guix archive}
  3916. automatically builds them. The build process may be controlled with the
  3917. common build options (@pxref{Common Build Options}).
  3918. To transfer the @code{emacs} package to a machine connected over SSH,
  3919. one would run:
  3920. @example
  3921. guix archive --export -r emacs | ssh the-machine guix archive --import
  3922. @end example
  3923. @noindent
  3924. Similarly, a complete user profile may be transferred from one machine
  3925. to another like this:
  3926. @example
  3927. guix archive --export -r $(readlink -f ~/.guix-profile) | \
  3928. ssh the-machine guix archive --import
  3929. @end example
  3930. @noindent
  3931. However, note that, in both examples, all of @code{emacs} and the
  3932. profile as well as all of their dependencies are transferred (due to
  3933. @option{-r}), regardless of what is already available in the store on
  3934. the target machine. The @option{--missing} option can help figure out
  3935. which items are missing from the target store. The @command{guix copy}
  3936. command simplifies and optimizes this whole process, so this is probably
  3937. what you should use in this case (@pxref{Invoking guix copy}).
  3938. @cindex nar, archive format
  3939. @cindex normalized archive (nar)
  3940. @cindex nar bundle, archive format
  3941. Each store item is written in the @dfn{normalized archive} or @dfn{nar}
  3942. format (described below), and the output of @command{guix archive
  3943. --export} (and input of @command{guix archive --import}) is a @dfn{nar
  3944. bundle}.
  3945. The nar format is
  3946. comparable in spirit to `tar', but with differences
  3947. that make it more appropriate for our purposes. First, rather than
  3948. recording all Unix metadata for each file, the nar format only mentions
  3949. the file type (regular, directory, or symbolic link); Unix permissions
  3950. and owner/group are dismissed. Second, the order in which directory
  3951. entries are stored always follows the order of file names according to
  3952. the C locale collation order. This makes archive production fully
  3953. deterministic.
  3954. That nar bundle format is essentially the concatenation of zero or more
  3955. nars along with metadata for each store item it contains: its file name,
  3956. references, corresponding derivation, and a digital signature.
  3957. When exporting, the daemon digitally signs the contents of the archive,
  3958. and that digital signature is appended. When importing, the daemon
  3959. verifies the signature and rejects the import in case of an invalid
  3960. signature or if the signing key is not authorized.
  3961. @c FIXME: Add xref to daemon doc about signatures.
  3962. The main options are:
  3963. @table @code
  3964. @item --export
  3965. Export the specified store files or packages (see below). Write the
  3966. resulting archive to the standard output.
  3967. Dependencies are @emph{not} included in the output, unless
  3968. @option{--recursive} is passed.
  3969. @item -r
  3970. @itemx --recursive
  3971. When combined with @option{--export}, this instructs @command{guix archive}
  3972. to include dependencies of the given items in the archive. Thus, the
  3973. resulting archive is self-contained: it contains the closure of the
  3974. exported store items.
  3975. @item --import
  3976. Read an archive from the standard input, and import the files listed
  3977. therein into the store. Abort if the archive has an invalid digital
  3978. signature, or if it is signed by a public key not among the authorized
  3979. keys (see @option{--authorize} below).
  3980. @item --missing
  3981. Read a list of store file names from the standard input, one per line,
  3982. and write on the standard output the subset of these files missing from
  3983. the store.
  3984. @item --generate-key[=@var{parameters}]
  3985. @cindex signing, archives
  3986. Generate a new key pair for the daemon. This is a prerequisite before
  3987. archives can be exported with @option{--export}. This
  3988. operation is usually instantaneous but it can take time if the system's
  3989. entropy pool needs to be refilled. On Guix System,
  3990. @code{guix-service-type} takes care of generating this key pair the
  3991. first boot.
  3992. The generated key pair is typically stored under @file{/etc/guix}, in
  3993. @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
  3994. key, which must be kept secret). When @var{parameters} is omitted,
  3995. an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
  3996. versions before 1.6.0, it is a 4096-bit RSA key.
  3997. Alternatively, @var{parameters} can specify
  3998. @code{genkey} parameters suitable for Libgcrypt (@pxref{General
  3999. public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
  4000. Libgcrypt Reference Manual}).
  4001. @item --authorize
  4002. @cindex authorizing, archives
  4003. Authorize imports signed by the public key passed on standard input.
  4004. The public key must be in ``s-expression advanced format''---i.e., the
  4005. same format as the @file{signing-key.pub} file.
  4006. The list of authorized keys is kept in the human-editable file
  4007. @file{/etc/guix/acl}. The file contains
  4008. @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
  4009. s-expressions''} and is structured as an access-control list in the
  4010. @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
  4011. (SPKI)}.
  4012. @item --extract=@var{directory}
  4013. @itemx -x @var{directory}
  4014. Read a single-item archive as served by substitute servers
  4015. (@pxref{Substitutes}) and extract it to @var{directory}. This is a
  4016. low-level operation needed in only very narrow use cases; see below.
  4017. For example, the following command extracts the substitute for Emacs
  4018. served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
  4019. @example
  4020. $ wget -O - \
  4021. https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
  4022. | gunzip | guix archive -x /tmp/emacs
  4023. @end example
  4024. Single-item archives are different from multiple-item archives produced
  4025. by @command{guix archive --export}; they contain a single store item,
  4026. and they do @emph{not} embed a signature. Thus this operation does
  4027. @emph{no} signature verification and its output should be considered
  4028. unsafe.
  4029. The primary purpose of this operation is to facilitate inspection of
  4030. archive contents coming from possibly untrusted substitute servers
  4031. (@pxref{Invoking guix challenge}).
  4032. @item --list
  4033. @itemx -t
  4034. Read a single-item archive as served by substitute servers
  4035. (@pxref{Substitutes}) and print the list of files it contains, as in
  4036. this example:
  4037. @example
  4038. $ wget -O - \
  4039. https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
  4040. | lzip -d | guix archive -t
  4041. @end example
  4042. @end table
  4043. @c *********************************************************************
  4044. @node Channels
  4045. @chapter Channels
  4046. @cindex channels
  4047. @cindex @file{channels.scm}, configuration file
  4048. @cindex configuration file for channels
  4049. @cindex @command{guix pull}, configuration file
  4050. @cindex configuration of @command{guix pull}
  4051. Guix and its package collection are updated by running @command{guix pull}
  4052. (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
  4053. deploys Guix itself from the official GNU@tie{}Guix repository. This can be
  4054. customized by defining @dfn{channels} in the
  4055. @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
  4056. of a Git repository to be deployed, and @command{guix pull} can be instructed
  4057. to pull from one or more channels. In other words, channels can be used
  4058. to @emph{customize} and to @emph{extend} Guix, as we will see below.
  4059. Guix is able to take into account security concerns and deal with authenticated
  4060. updates.
  4061. @menu
  4062. * Specifying Additional Channels:: Extending the package collection.
  4063. * Using a Custom Guix Channel:: Using a customized Guix.
  4064. * Replicating Guix:: Running the @emph{exact same} Guix.
  4065. * Channel Authentication:: How Guix verifies what it fetches.
  4066. * Creating a Channel:: How to write your custom channel.
  4067. * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
  4068. * Declaring Channel Dependencies:: How to depend on other channels.
  4069. * Specifying Channel Authorizations:: Defining channel authors authorizations.
  4070. * Primary URL:: Distinguishing mirror to original.
  4071. * Writing Channel News:: Communicating information to channel's users.
  4072. * Channels with Substitutes:: Using channels with available substitutes.
  4073. @end menu
  4074. @node Specifying Additional Channels
  4075. @section Specifying Additional Channels
  4076. @cindex extending the package collection (channels)
  4077. @cindex variant packages (channels)
  4078. You can specify @emph{additional channels} to pull from. To use a channel, write
  4079. @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
  4080. @emph{in addition} to the default Guix channel(s):
  4081. @vindex %default-channels
  4082. @lisp
  4083. ;; Add variant packages to those Guix provides.
  4084. (cons (channel
  4085. (name 'variant-packages)
  4086. (url "https://example.org/variant-packages.git"))
  4087. %default-channels)
  4088. @end lisp
  4089. @noindent
  4090. Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
  4091. add a channel the list of channels that the variable @code{%default-channels}
  4092. is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
  4093. Manual}). With this file in place, @command{guix pull} builds not only Guix
  4094. but also the package modules from your own repository. The result in
  4095. @file{~/.config/guix/current} is the union of Guix with your own package
  4096. modules:
  4097. @example
  4098. $ guix pull --list-generations
  4099. @dots{}
  4100. Generation 19 Aug 27 2018 16:20:48
  4101. guix d894ab8
  4102. repository URL: https://git.savannah.gnu.org/git/guix.git
  4103. branch: master
  4104. commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
  4105. variant-packages dd3df5e
  4106. repository URL: https://example.org/variant-packages.git
  4107. branch: master
  4108. commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
  4109. 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
  4110. 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
  4111. @end example
  4112. @noindent
  4113. The output of @command{guix pull} above shows that Generation@tie{}19 includes
  4114. both Guix and packages from the @code{variant-personal-packages} channel. Among
  4115. the new and upgraded packages that are listed, some like @code{variant-gimp} and
  4116. @code{variant-emacs-with-cool-features} might come from
  4117. @code{variant-packages}, while others come from the Guix default channel.
  4118. @node Using a Custom Guix Channel
  4119. @section Using a Custom Guix Channel
  4120. The channel called @code{guix} specifies where Guix itself---its command-line
  4121. tools as well as its package collection---should be downloaded. For instance,
  4122. suppose you want to update from another copy of the Guix repository at
  4123. @code{example.org}, and specifically the @code{super-hacks} branch, you can
  4124. write in @code{~/.config/guix/channels.scm} this specification:
  4125. @lisp
  4126. ;; Tell 'guix pull' to use another repo.
  4127. (list (channel
  4128. (name 'guix)
  4129. (url "https://example.org/another-guix.git")
  4130. (branch "super-hacks")))
  4131. @end lisp
  4132. @noindent
  4133. From there on, @command{guix pull} will fetch code from the @code{super-hacks}
  4134. branch of the repository at @code{example.org}. The authentication concern is
  4135. addressed below ((@pxref{Channel Authentication}).
  4136. @node Replicating Guix
  4137. @section Replicating Guix
  4138. @cindex pinning, channels
  4139. @cindex replicating Guix
  4140. @cindex reproducibility, of Guix
  4141. The @command{guix pull --list-generations} output above shows precisely which
  4142. commits were used to build this instance of Guix. We can thus replicate it,
  4143. say, on another machine, by providing a channel specification in
  4144. @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
  4145. @lisp
  4146. ;; Deploy specific commits of my channels of interest.
  4147. (list (channel
  4148. (name 'guix)
  4149. (url "https://git.savannah.gnu.org/git/guix.git")
  4150. (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
  4151. (channel
  4152. (name 'variant-packages)
  4153. (url "https://example.org/variant-packages.git")
  4154. (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
  4155. @end lisp
  4156. The @command{guix describe --format=channels} command can even generate this
  4157. list of channels directly (@pxref{Invoking guix describe}). The resulting
  4158. file can be used with the -C options of @command{guix pull}
  4159. (@pxref{Invoking guix pull}) or @command{guix time-machine}
  4160. (@pxref{Invoking guix time-machine}).
  4161. At this point the two machines run the @emph{exact same Guix}, with access to
  4162. the @emph{exact same packages}. The output of @command{guix build gimp} on
  4163. one machine will be exactly the same, bit for bit, as the output of the same
  4164. command on the other machine. It also means both machines have access to all
  4165. the source code of Guix and, transitively, to all the source code of every
  4166. package it defines.
  4167. This gives you super powers, allowing you to track the provenance of binary
  4168. artifacts with very fine grain, and to reproduce software environments at
  4169. will---some sort of ``meta reproducibility'' capabilities, if you will.
  4170. @xref{Inferiors}, for another way to take advantage of these super powers.
  4171. @node Channel Authentication
  4172. @section Channel Authentication
  4173. @anchor{channel-authentication}
  4174. @cindex authentication, of channel code
  4175. The @command{guix pull} and @command{guix time-machine} commands
  4176. @dfn{authenticate} the code retrieved from channels: they make sure each
  4177. commit that is fetched is signed by an authorized developer. The goal
  4178. is to protect from unauthorized modifications to the channel that would
  4179. lead users to run malicious code.
  4180. As a user, you must provide a @dfn{channel introduction} in your
  4181. channels file so that Guix knows how to authenticate its first commit.
  4182. A channel specification, including its introduction, looks something
  4183. along these lines:
  4184. @lisp
  4185. (channel
  4186. (name 'some-channel)
  4187. (url "https://example.org/some-channel.git")
  4188. (introduction
  4189. (make-channel-introduction
  4190. "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
  4191. (openpgp-fingerprint
  4192. "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
  4193. @end lisp
  4194. The specification above shows the name and URL of the channel. The call
  4195. to @code{make-channel-introduction} above specifies that authentication
  4196. of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
  4197. by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
  4198. For the main channel, called @code{guix}, you automatically get that
  4199. information from your Guix installation. For other channels, include
  4200. the channel introduction provided by the channel authors in your
  4201. @file{channels.scm} file. Make sure you retrieve the channel
  4202. introduction from a trusted source since that is the root of your trust.
  4203. If you're curious about the authentication mechanics, read on!
  4204. @node Creating a Channel
  4205. @section Creating a Channel
  4206. @cindex personal packages (channels)
  4207. @cindex channels, for personal packages
  4208. Let's say you have a bunch of custom package variants or personal packages
  4209. that you think would make little sense to contribute to the Guix project, but
  4210. would like to have these packages transparently available to you at the
  4211. command line. You would first write modules containing those package
  4212. definitions (@pxref{Package Modules}), maintain them in a Git repository, and
  4213. then you and anyone else can use it as an additional channel to get packages
  4214. from. Neat, no?
  4215. @c What follows stems from discussions at
  4216. @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
  4217. @c earlier discussions on guix-devel@gnu.org.
  4218. @quotation Warning
  4219. Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
  4220. publish your personal channel to the world, we would like to share a few words
  4221. of caution:
  4222. @itemize
  4223. @item
  4224. Before publishing a channel, please consider contributing your package
  4225. definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
  4226. to free software of all sorts, and packages in Guix proper are readily
  4227. available to all Guix users and benefit from the project's quality assurance
  4228. process.
  4229. @item
  4230. When you maintain package definitions outside Guix, we, Guix developers,
  4231. consider that @emph{the compatibility burden is on you}. Remember that
  4232. package modules and package definitions are just Scheme code that uses various
  4233. programming interfaces (APIs). We want to remain free to change these APIs to
  4234. keep improving Guix, possibly in ways that break your channel. We never
  4235. change APIs gratuitously, but we will @emph{not} commit to freezing APIs
  4236. either.
  4237. @item
  4238. Corollary: if you're using an external channel and that channel breaks, please
  4239. @emph{report the issue to the channel authors}, not to the Guix project.
  4240. @end itemize
  4241. You've been warned! Having said this, we believe external channels are a
  4242. practical way to exert your freedom to augment Guix' package collection and to
  4243. share your improvements, which are basic tenets of
  4244. @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
  4245. email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
  4246. @end quotation
  4247. To create a channel, create a Git repository containing your own package
  4248. modules and make it available. The repository can contain anything, but a
  4249. useful channel will contain Guile modules that export packages. Once you
  4250. start using a channel, Guix will behave as if the root directory of that
  4251. channel's Git repository has been added to the Guile load path (@pxref{Load
  4252. Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
  4253. contains a file at @file{my-packages/my-tools.scm} that defines a Guile
  4254. module, then the module will be available under the name @code{(my-packages
  4255. my-tools)}, and you will be able to use it like any other module
  4256. (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
  4257. As a channel author, consider bundling authentication material with your
  4258. channel so that users can authenticate it. @xref{Channel
  4259. Authentication}, and @ref{Specifying Channel Authorizations}, for info
  4260. on how to do it.
  4261. @node Package Modules in a Sub-directory
  4262. @section Package Modules in a Sub-directory
  4263. @cindex subdirectory, channels
  4264. As a channel author, you may want to keep your channel modules in a
  4265. sub-directory. If your modules are in the sub-directory @file{guix}, you must
  4266. add a meta-data file @file{.guix-channel} that contains:
  4267. @lisp
  4268. (channel
  4269. (version 0)
  4270. (directory "guix"))
  4271. @end lisp
  4272. @node Declaring Channel Dependencies
  4273. @section Declaring Channel Dependencies
  4274. @cindex dependencies, channels
  4275. @cindex meta-data, channels
  4276. Channel authors may decide to augment a package collection provided by other
  4277. channels. They can declare their channel to be dependent on other channels in
  4278. a meta-data file @file{.guix-channel}, which is to be placed in the root of
  4279. the channel repository.
  4280. The meta-data file should contain a simple S-expression like this:
  4281. @lisp
  4282. (channel
  4283. (version 0)
  4284. (dependencies
  4285. (channel
  4286. (name 'some-collection)
  4287. (url "https://example.org/first-collection.git")
  4288. ;; The 'introduction' bit below is optional: you would
  4289. ;; provide it for dependencies that can be authenticated.
  4290. (introduction
  4291. (channel-introduction
  4292. (version 0)
  4293. (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
  4294. (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
  4295. (channel
  4296. (name 'some-other-collection)
  4297. (url "https://example.org/second-collection.git")
  4298. (branch "testing"))))
  4299. @end lisp
  4300. In the above example this channel is declared to depend on two other channels,
  4301. which will both be fetched automatically. The modules provided by the channel
  4302. will be compiled in an environment where the modules of all these declared
  4303. channels are available.
  4304. For the sake of reliability and maintainability, you should avoid dependencies
  4305. on channels that you don't control, and you should aim to keep the number of
  4306. dependencies to a minimum.
  4307. @node Specifying Channel Authorizations
  4308. @section Specifying Channel Authorizations
  4309. @cindex channel authorizations
  4310. @anchor{channel-authorizations}
  4311. As we saw above, Guix ensures the source code it pulls from channels
  4312. comes from authorized developers. As a channel author, you need to
  4313. specify the list of authorized developers in the
  4314. @file{.guix-authorizations} file in the channel's Git repository. The
  4315. authentication rule is simple: each commit must be signed by a key
  4316. listed in the @file{.guix-authorizations} file of its parent
  4317. commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
  4318. (DAG). Each commit can have zero or more parents; ``regular'' commits
  4319. have one parent and merge commits have two parent commits. Read
  4320. @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
  4321. for Computer Scientists}} for a great overview.} The
  4322. @file{.guix-authorizations} file looks like this:
  4323. @lisp
  4324. ;; Example '.guix-authorizations' file.
  4325. (authorizations
  4326. (version 0) ;current file format version
  4327. (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
  4328. (name "alice"))
  4329. ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
  4330. (name "bob"))
  4331. ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
  4332. (name "charlie"))))
  4333. @end lisp
  4334. Each fingerprint is followed by optional key/value pairs, as in the
  4335. example above. Currently these key/value pairs are ignored.
  4336. This authentication rule creates a chicken-and-egg issue: how do we
  4337. authenticate the first commit? Related to that: how do we deal with
  4338. channels whose repository history contains unsigned commits and lack
  4339. @file{.guix-authorizations}? And how do we fork existing channels?
  4340. @cindex channel introduction
  4341. Channel introductions answer these questions by describing the first
  4342. commit of a channel that should be authenticated. The first time a
  4343. channel is fetched with @command{guix pull} or @command{guix
  4344. time-machine}, the command looks up the introductory commit and verifies
  4345. that it is signed by the specified OpenPGP key. From then on, it
  4346. authenticates commits according to the rule above.
  4347. Additionally, your channel must provide all the OpenPGP keys that were
  4348. ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
  4349. files, which can be either binary or ``ASCII-armored''. By default,
  4350. those @file{.key} files are searched for in the branch named
  4351. @code{keyring} but you can specify a different branch name in
  4352. @code{.guix-channel} like so:
  4353. @lisp
  4354. (channel
  4355. (version 0)
  4356. (keyring-reference "my-keyring-branch"))
  4357. @end lisp
  4358. To summarize, as the author of a channel, there are three things you have
  4359. to do to allow users to authenticate your code:
  4360. @enumerate
  4361. @item
  4362. Export the OpenPGP keys of past and present committers with @command{gpg
  4363. --export} and store them in @file{.key} files, by default in a branch
  4364. named @code{keyring} (we recommend making it an @dfn{orphan branch}).
  4365. @item
  4366. Introduce an initial @file{.guix-authorizations} in the channel's
  4367. repository. Do that in a signed commit (@pxref{Commit Access}, for
  4368. information on how to sign Git commits.)
  4369. @item
  4370. Advertise the channel introduction, for instance on your channel's web
  4371. page. The channel introduction, as we saw above, is the commit/key
  4372. pair---i.e., the commit that introduced @file{.guix-authorizations}, and
  4373. the fingerprint of the OpenPGP used to sign it.
  4374. @end enumerate
  4375. Before pushing to your public Git repository, you can run @command{guix
  4376. git-authenticate} to verify that you did sign all the commits you are
  4377. about to push with an authorized key:
  4378. @example
  4379. guix git authenticate @var{commit} @var{signer}
  4380. @end example
  4381. @noindent
  4382. where @var{commit} and @var{signer} are your channel introduction.
  4383. @xref{Invoking guix git authenticate}, for details.
  4384. Publishing a signed channel requires discipline: any mistake, such as an
  4385. unsigned commit or a commit signed by an unauthorized key, will prevent
  4386. users from pulling from your channel---well, that's the whole point of
  4387. authentication! Pay attention to merges in particular: merge commits
  4388. are considered authentic if and only if they are signed by a key present
  4389. in the @file{.guix-authorizations} file of @emph{both} branches.
  4390. @node Primary URL
  4391. @section Primary URL
  4392. @cindex primary URL, channels
  4393. Channel authors can indicate the primary URL of their channel's Git
  4394. repository in the @file{.guix-channel} file, like so:
  4395. @lisp
  4396. (channel
  4397. (version 0)
  4398. (url "https://example.org/guix.git"))
  4399. @end lisp
  4400. This allows @command{guix pull} to determine whether it is pulling code
  4401. from a mirror of the channel; when that is the case, it warns the user
  4402. that the mirror might be stale and displays the primary URL@. That way,
  4403. users cannot be tricked into fetching code from a stale mirror that does
  4404. not receive security updates.
  4405. This feature only makes sense for authenticated repositories, such as
  4406. the official @code{guix} channel, for which @command{guix pull} ensures
  4407. the code it fetches is authentic.
  4408. @node Writing Channel News
  4409. @section Writing Channel News
  4410. @cindex news, for channels
  4411. Channel authors may occasionally want to communicate to their users
  4412. information about important changes in the channel. You'd send them all
  4413. an email, but that's not convenient.
  4414. Instead, channels can provide a @dfn{news file}; when the channel users
  4415. run @command{guix pull}, that news file is automatically read and
  4416. @command{guix pull --news} can display the announcements that correspond
  4417. to the new commits that have been pulled, if any.
  4418. To do that, channel authors must first declare the name of the news file
  4419. in their @file{.guix-channel} file:
  4420. @lisp
  4421. (channel
  4422. (version 0)
  4423. (news-file "etc/news.txt"))
  4424. @end lisp
  4425. The news file itself, @file{etc/news.txt} in this example, must look
  4426. something like this:
  4427. @lisp
  4428. (channel-news
  4429. (version 0)
  4430. (entry (tag "the-bug-fix")
  4431. (title (en "Fixed terrible bug")
  4432. (fr "Oh la la"))
  4433. (body (en "@@emph@{Good news@}! It's fixed!")
  4434. (eo "Certe ĝi pli bone funkcias nun!")))
  4435. (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
  4436. (title (en "Added a great package")
  4437. (ca "Què vol dir guix?"))
  4438. (body (en "Don't miss the @@code@{hello@} package!"))))
  4439. @end lisp
  4440. While the news file is using the Scheme syntax, avoid naming it with a
  4441. @file{.scm} extension or else it will get picked up when building the
  4442. channel and yield an error since it is not a valid module.
  4443. Alternatively, you can move the channel module to a subdirectory and
  4444. store the news file in another directory.
  4445. The file consists of a list of @dfn{news entries}. Each entry is
  4446. associated with a commit or tag: it describes changes made in this
  4447. commit, possibly in preceding commits as well. Users see entries only
  4448. the first time they obtain the commit the entry refers to.
  4449. The @code{title} field should be a one-line summary while @code{body}
  4450. can be arbitrarily long, and both can contain Texinfo markup
  4451. (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
  4452. a list of language tag/message tuples, which allows @command{guix pull}
  4453. to display news in the language that corresponds to the user's locale.
  4454. If you want to translate news using a gettext-based workflow, you can
  4455. extract translatable strings with @command{xgettext} (@pxref{xgettext
  4456. Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
  4457. you write news entries in English first, the command below creates a PO
  4458. file containing the strings to translate:
  4459. @example
  4460. xgettext -o news.po -l scheme -ken etc/news.txt
  4461. @end example
  4462. To sum up, yes, you could use your channel as a blog. But beware, this
  4463. is @emph{not quite} what your users might expect.
  4464. @node Channels with Substitutes
  4465. @section Channels with Substitutes
  4466. When running @command{guix pull}, Guix will first compile the
  4467. definitions of every available package. This is an expensive operation
  4468. for which substitutes (@pxref{Substitutes}) may be available. The
  4469. following snippet in @file{channels.scm} will ensure that @command{guix
  4470. pull} uses the latest commit with available substitutes for the package
  4471. definitions: this is done by querying the continuous integration
  4472. server at @url{https://ci.guix.gnu.org}.
  4473. @lisp
  4474. (use-modules (guix ci))
  4475. (list (channel-with-substitutes-available
  4476. %default-guix-channel
  4477. "https://ci.guix.gnu.org"))
  4478. @end lisp
  4479. Note that this does not mean that all the packages that you will
  4480. install after running @command{guix pull} will have available
  4481. substitutes. It only ensures that @command{guix pull} will not try to
  4482. compile package definitions. This is particularly useful when using
  4483. machines with limited resources.
  4484. @c *********************************************************************
  4485. @node Development
  4486. @chapter Development
  4487. @cindex software development
  4488. If you are a software developer, Guix provides tools that you should find
  4489. helpful---independently of the language you're developing in. This is what
  4490. this chapter is about.
  4491. The @command{guix environment} command provides a convenient way to set up
  4492. @dfn{development environments} containing all the dependencies and tools
  4493. necessary to work on the software package of your choice. The @command{guix
  4494. pack} command allows you to create @dfn{application bundles} that can be
  4495. easily distributed to users who do not run Guix.
  4496. @menu
  4497. * Invoking guix environment:: Setting up development environments.
  4498. * Invoking guix pack:: Creating software bundles.
  4499. * The GCC toolchain:: Working with languages supported by GCC.
  4500. * Invoking guix git authenticate:: Authenticating Git repositories.
  4501. @end menu
  4502. @node Invoking guix environment
  4503. @section Invoking @command{guix environment}
  4504. @cindex reproducible build environments
  4505. @cindex development environments
  4506. @cindex @command{guix environment}
  4507. @cindex environment, package build environment
  4508. The purpose of @command{guix environment} is to assist hackers in
  4509. creating reproducible development environments without polluting their
  4510. package profile. The @command{guix environment} tool takes one or more
  4511. packages, builds all of their inputs, and creates a shell
  4512. environment to use them.
  4513. The general syntax is:
  4514. @example
  4515. guix environment @var{options} @var{package}@dots{}
  4516. @end example
  4517. The following example spawns a new shell set up for the development of
  4518. GNU@tie{}Guile:
  4519. @example
  4520. guix environment guile
  4521. @end example
  4522. If the needed dependencies are not built yet, @command{guix environment}
  4523. automatically builds them. The environment of the new shell is an
  4524. augmented version of the environment that @command{guix environment} was
  4525. run in. It contains the necessary search paths for building the given
  4526. package added to the existing environment variables. To create
  4527. a ``pure'' environment, in which the original environment variables have
  4528. been unset, use the @option{--pure} option@footnote{Users sometimes
  4529. wrongfully augment environment variables such as @env{PATH} in their
  4530. @file{~/.bashrc} file. As a consequence, when @command{guix
  4531. environment} launches it, Bash may read @file{~/.bashrc}, thereby
  4532. introducing ``impurities'' in these environment variables. It is an
  4533. error to define such environment variables in @file{.bashrc}; instead,
  4534. they should be defined in @file{.bash_profile}, which is sourced only by
  4535. log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
  4536. Manual}, for details on Bash start-up files.}.
  4537. Exiting from a Guix environment is the same as exiting from the shell,
  4538. and will place the user back in the old environment before @command{guix
  4539. environment} was invoked. The next garbage collection (@pxref{Invoking
  4540. guix gc}) will clean up packages that were installed from within the
  4541. environment and are no longer used outside of it.
  4542. @vindex GUIX_ENVIRONMENT
  4543. @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
  4544. variable in the shell it spawns; its value is the file name of the
  4545. profile of this environment. This allows users to, say, define a
  4546. specific prompt for development environments in their @file{.bashrc}
  4547. (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
  4548. @example
  4549. if [ -n "$GUIX_ENVIRONMENT" ]
  4550. then
  4551. export PS1="\u@@\h \w [dev]\$ "
  4552. fi
  4553. @end example
  4554. @noindent
  4555. ...@: or to browse the profile:
  4556. @example
  4557. $ ls "$GUIX_ENVIRONMENT/bin"
  4558. @end example
  4559. Additionally, more than one package may be specified, in which case the
  4560. union of the inputs for the given packages are used. For example, the
  4561. command below spawns a shell where all of the dependencies of both Guile
  4562. and Emacs are available:
  4563. @example
  4564. guix environment guile emacs
  4565. @end example
  4566. Sometimes an interactive shell session is not desired. An arbitrary
  4567. command may be invoked by placing the @code{--} token to separate the
  4568. command from the rest of the arguments:
  4569. @example
  4570. guix environment guile -- make -j4
  4571. @end example
  4572. In other situations, it is more convenient to specify the list of
  4573. packages needed in the environment. For example, the following command
  4574. runs @command{python} from an environment containing Python@tie{}2.7 and
  4575. NumPy:
  4576. @example
  4577. guix environment --ad-hoc python2-numpy python-2.7 -- python
  4578. @end example
  4579. Furthermore, one might want the dependencies of a package and also some
  4580. additional packages that are not build-time or runtime dependencies, but
  4581. are useful when developing nonetheless. Because of this, the
  4582. @option{--ad-hoc} flag is positional. Packages appearing before
  4583. @option{--ad-hoc} are interpreted as packages whose dependencies will be
  4584. added to the environment. Packages appearing after are interpreted as
  4585. packages that will be added to the environment directly. For example,
  4586. the following command creates a Guix development environment that
  4587. additionally includes Git and strace:
  4588. @example
  4589. guix environment --pure guix --ad-hoc git strace
  4590. @end example
  4591. @cindex container
  4592. Sometimes it is desirable to isolate the environment as much as
  4593. possible, for maximal purity and reproducibility. In particular, when
  4594. using Guix on a host distro that is not Guix System, it is desirable to
  4595. prevent access to @file{/usr/bin} and other system-wide resources from
  4596. the development environment. For example, the following command spawns
  4597. a Guile REPL in a ``container'' where only the store and the current
  4598. working directory are mounted:
  4599. @example
  4600. guix environment --ad-hoc --container guile -- guile
  4601. @end example
  4602. @quotation Note
  4603. The @option{--container} option requires Linux-libre 3.19 or newer.
  4604. @end quotation
  4605. @cindex certificates
  4606. Another typical use case for containers is to run security-sensitive
  4607. applications such as a web browser. To run Eolie, we must expose and
  4608. share some files and directories; we include @code{nss-certs} and expose
  4609. @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
  4610. @env{DISPLAY} environment variable since containerized graphical
  4611. applications won't display without it.
  4612. @example
  4613. guix environment --preserve='^DISPLAY$' --container --network \
  4614. --expose=/etc/machine-id \
  4615. --expose=/etc/ssl/certs/ \
  4616. --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
  4617. --ad-hoc eolie nss-certs dbus -- eolie
  4618. @end example
  4619. The available options are summarized below.
  4620. @table @code
  4621. @item --root=@var{file}
  4622. @itemx -r @var{file}
  4623. @cindex persistent environment
  4624. @cindex garbage collector root, for environments
  4625. Make @var{file} a symlink to the profile for this environment, and
  4626. register it as a garbage collector root.
  4627. This is useful if you want to protect your environment from garbage
  4628. collection, to make it ``persistent''.
  4629. When this option is omitted, the environment is protected from garbage
  4630. collection only for the duration of the @command{guix environment}
  4631. session. This means that next time you recreate the same environment,
  4632. you could have to rebuild or re-download packages. @xref{Invoking guix
  4633. gc}, for more on GC roots.
  4634. @item --expression=@var{expr}
  4635. @itemx -e @var{expr}
  4636. Create an environment for the package or list of packages that
  4637. @var{expr} evaluates to.
  4638. For example, running:
  4639. @example
  4640. guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
  4641. @end example
  4642. starts a shell with the environment for this specific variant of the
  4643. PETSc package.
  4644. Running:
  4645. @example
  4646. guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
  4647. @end example
  4648. starts a shell with all the base system packages available.
  4649. The above commands only use the default output of the given packages.
  4650. To select other outputs, two element tuples can be specified:
  4651. @example
  4652. guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
  4653. @end example
  4654. @item --load=@var{file}
  4655. @itemx -l @var{file}
  4656. Create an environment for the package or list of packages that the code
  4657. within @var{file} evaluates to.
  4658. As an example, @var{file} might contain a definition like this
  4659. (@pxref{Defining Packages}):
  4660. @lisp
  4661. @verbatiminclude environment-gdb.scm
  4662. @end lisp
  4663. @item --manifest=@var{file}
  4664. @itemx -m @var{file}
  4665. Create an environment for the packages contained in the manifest object
  4666. returned by the Scheme code in @var{file}. This option can be repeated
  4667. several times, in which case the manifests are concatenated.
  4668. This is similar to the same-named option in @command{guix package}
  4669. (@pxref{profile-manifest, @option{--manifest}}) and uses the same
  4670. manifest files.
  4671. @item --ad-hoc
  4672. Include all specified packages in the resulting environment, as if an
  4673. @i{ad hoc} package were defined with them as inputs. This option is
  4674. useful for quickly creating an environment without having to write a
  4675. package expression to contain the desired inputs.
  4676. For instance, the command:
  4677. @example
  4678. guix environment --ad-hoc guile guile-sdl -- guile
  4679. @end example
  4680. runs @command{guile} in an environment where Guile and Guile-SDL are
  4681. available.
  4682. Note that this example implicitly asks for the default output of
  4683. @code{guile} and @code{guile-sdl}, but it is possible to ask for a
  4684. specific output---e.g., @code{glib:bin} asks for the @code{bin} output
  4685. of @code{glib} (@pxref{Packages with Multiple Outputs}).
  4686. This option may be composed with the default behavior of @command{guix
  4687. environment}. Packages appearing before @option{--ad-hoc} are
  4688. interpreted as packages whose dependencies will be added to the
  4689. environment, the default behavior. Packages appearing after are
  4690. interpreted as packages that will be added to the environment directly.
  4691. @item --pure
  4692. Unset existing environment variables when building the new environment, except
  4693. those specified with @option{--preserve} (see below). This has the effect of
  4694. creating an environment in which search paths only contain package inputs.
  4695. @item --preserve=@var{regexp}
  4696. @itemx -E @var{regexp}
  4697. When used alongside @option{--pure}, preserve the environment variables
  4698. matching @var{regexp}---in other words, put them on a ``white list'' of
  4699. environment variables that must be preserved. This option can be repeated
  4700. several times.
  4701. @example
  4702. guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
  4703. -- mpirun @dots{}
  4704. @end example
  4705. This example runs @command{mpirun} in a context where the only environment
  4706. variables defined are @env{PATH}, environment variables whose name starts
  4707. with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
  4708. @env{USER}, etc.).
  4709. @item --search-paths
  4710. Display the environment variable definitions that make up the
  4711. environment.
  4712. @item --system=@var{system}
  4713. @itemx -s @var{system}
  4714. Attempt to build for @var{system}---e.g., @code{i686-linux}.
  4715. @item --container
  4716. @itemx -C
  4717. @cindex container
  4718. Run @var{command} within an isolated container. The current working
  4719. directory outside the container is mapped inside the container.
  4720. Additionally, unless overridden with @option{--user}, a dummy home
  4721. directory is created that matches the current user's home directory, and
  4722. @file{/etc/passwd} is configured accordingly.
  4723. The spawned process runs as the current user outside the container. Inside
  4724. the container, it has the same UID and GID as the current user, unless
  4725. @option{--user} is passed (see below).
  4726. @item --network
  4727. @itemx -N
  4728. For containers, share the network namespace with the host system.
  4729. Containers created without this flag only have access to the loopback
  4730. device.
  4731. @item --link-profile
  4732. @itemx -P
  4733. For containers, link the environment profile to @file{~/.guix-profile}
  4734. within the container and set @code{GUIX_ENVIRONMENT} to that.
  4735. This is equivalent to making @file{~/.guix-profile} a symlink to the
  4736. actual profile within the container.
  4737. Linking will fail and abort the environment if the directory already
  4738. exists, which will certainly be the case if @command{guix environment}
  4739. was invoked in the user's home directory.
  4740. Certain packages are configured to look in @file{~/.guix-profile} for
  4741. configuration files and data;@footnote{For example, the
  4742. @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
  4743. for additional fonts.} @option{--link-profile} allows these programs to
  4744. behave as expected within the environment.
  4745. @item --user=@var{user}
  4746. @itemx -u @var{user}
  4747. For containers, use the username @var{user} in place of the current
  4748. user. The generated @file{/etc/passwd} entry within the container will
  4749. contain the name @var{user}, the home directory will be
  4750. @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
  4751. the UID and GID inside the container are 1000. @var{user}
  4752. need not exist on the system.
  4753. Additionally, any shared or exposed path (see @option{--share} and
  4754. @option{--expose} respectively) whose target is within the current user's
  4755. home directory will be remapped relative to @file{/home/USER}; this
  4756. includes the automatic mapping of the current working directory.
  4757. @example
  4758. # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
  4759. cd $HOME/wd
  4760. guix environment --container --user=foo \
  4761. --expose=$HOME/test \
  4762. --expose=/tmp/target=$HOME/target
  4763. @end example
  4764. While this will limit the leaking of user identity through home paths
  4765. and each of the user fields, this is only one useful component of a
  4766. broader privacy/anonymity solution---not one in and of itself.
  4767. @item --no-cwd
  4768. For containers, the default behavior is to share the current working
  4769. directory with the isolated container and immediately change to that
  4770. directory within the container. If this is undesirable,
  4771. @option{--no-cwd} will cause the current working directory to @emph{not}
  4772. be automatically shared and will change to the user's home directory
  4773. within the container instead. See also @option{--user}.
  4774. @item --expose=@var{source}[=@var{target}]
  4775. @itemx --share=@var{source}[=@var{target}]
  4776. For containers, @option{--expose} (resp. @option{--share}) exposes the
  4777. file system @var{source} from the host system as the read-only
  4778. (resp. writable) file system @var{target} within the container. If
  4779. @var{target} is not specified, @var{source} is used as the target mount
  4780. point in the container.
  4781. The example below spawns a Guile REPL in a container in which the user's
  4782. home directory is accessible read-only via the @file{/exchange}
  4783. directory:
  4784. @example
  4785. guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
  4786. @end example
  4787. @end table
  4788. @command{guix environment}
  4789. also supports all of the common build options that @command{guix
  4790. build} supports (@pxref{Common Build Options}) as well as package
  4791. transformation options (@pxref{Package Transformation Options}).
  4792. @node Invoking guix pack
  4793. @section Invoking @command{guix pack}
  4794. Occasionally you want to pass software to people who are not (yet!)
  4795. lucky enough to be using Guix. You'd tell them to run @command{guix
  4796. package -i @var{something}}, but that's not possible in this case. This
  4797. is where @command{guix pack} comes in.
  4798. @quotation Note
  4799. If you are looking for ways to exchange binaries among machines that
  4800. already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
  4801. publish}, and @ref{Invoking guix archive}.
  4802. @end quotation
  4803. @cindex pack
  4804. @cindex bundle
  4805. @cindex application bundle
  4806. @cindex software bundle
  4807. The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
  4808. @dfn{software bundle}: it creates a tarball or some other archive
  4809. containing the binaries of the software you're interested in, and all
  4810. its dependencies. The resulting archive can be used on any machine that
  4811. does not have Guix, and people can run the exact same binaries as those
  4812. you have with Guix. The pack itself is created in a bit-reproducible
  4813. fashion, so anyone can verify that it really contains the build results
  4814. that you pretend to be shipping.
  4815. For example, to create a bundle containing Guile, Emacs, Geiser, and all
  4816. their dependencies, you can run:
  4817. @example
  4818. $ guix pack guile emacs geiser
  4819. @dots{}
  4820. /gnu/store/@dots{}-pack.tar.gz
  4821. @end example
  4822. The result here is a tarball containing a @file{/gnu/store} directory
  4823. with all the relevant packages. The resulting tarball contains a
  4824. @dfn{profile} with the three packages of interest; the profile is the
  4825. same as would be created by @command{guix package -i}. It is this
  4826. mechanism that is used to create Guix's own standalone binary tarball
  4827. (@pxref{Binary Installation}).
  4828. Users of this pack would have to run
  4829. @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
  4830. find inconvenient. To work around it, you can create, say, a
  4831. @file{/opt/gnu/bin} symlink to the profile:
  4832. @example
  4833. guix pack -S /opt/gnu/bin=bin guile emacs geiser
  4834. @end example
  4835. @noindent
  4836. That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
  4837. @cindex relocatable binaries, with @command{guix pack}
  4838. What if the recipient of your pack does not have root privileges on
  4839. their machine, and thus cannot unpack it in the root file system? In
  4840. that case, you will want to use the @option{--relocatable} option (see
  4841. below). This option produces @dfn{relocatable binaries}, meaning they
  4842. they can be placed anywhere in the file system hierarchy: in the example
  4843. above, users can unpack your tarball in their home directory and
  4844. directly run @file{./opt/gnu/bin/guile}.
  4845. @cindex Docker, build an image with guix pack
  4846. Alternatively, you can produce a pack in the Docker image format using
  4847. the following command:
  4848. @example
  4849. guix pack -f docker -S /bin=bin guile guile-readline
  4850. @end example
  4851. @noindent
  4852. The result is a tarball that can be passed to the @command{docker load}
  4853. command, followed by @code{docker run}:
  4854. @example
  4855. docker load < @var{file}
  4856. docker run -ti guile-guile-readline /bin/guile
  4857. @end example
  4858. @noindent
  4859. where @var{file} is the image returned by @var{guix pack}, and
  4860. @code{guile-guile-readline} is its ``image tag''. See the
  4861. @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
  4862. documentation} for more information.
  4863. @cindex Singularity, build an image with guix pack
  4864. @cindex SquashFS, build an image with guix pack
  4865. Yet another option is to produce a SquashFS image with the following
  4866. command:
  4867. @example
  4868. guix pack -f squashfs bash guile emacs geiser
  4869. @end example
  4870. @noindent
  4871. The result is a SquashFS file system image that can either be mounted or
  4872. directly be used as a file system container image with the
  4873. @uref{https://www.sylabs.io/docs/, Singularity container execution
  4874. environment}, using commands like @command{singularity shell} or
  4875. @command{singularity exec}.
  4876. Several command-line options allow you to customize your pack:
  4877. @table @code
  4878. @item --format=@var{format}
  4879. @itemx -f @var{format}
  4880. Produce a pack in the given @var{format}.
  4881. The available formats are:
  4882. @table @code
  4883. @item tarball
  4884. This is the default format. It produces a tarball containing all the
  4885. specified binaries and symlinks.
  4886. @item docker
  4887. This produces a tarball that follows the
  4888. @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
  4889. Docker Image Specification}. The ``repository name'' as it appears in
  4890. the output of the @command{docker images} command is computed from
  4891. package names passed on the command line or in the manifest file.
  4892. @item squashfs
  4893. This produces a SquashFS image containing all the specified binaries and
  4894. symlinks, as well as empty mount points for virtual file systems like
  4895. procfs.
  4896. @quotation Note
  4897. Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
  4898. For that reason, @command{guix pack -f squashfs} always implies @code{-S
  4899. /bin=bin}. Thus, your @command{guix pack} invocation must always start
  4900. with something like:
  4901. @example
  4902. guix pack -f squashfs bash @dots{}
  4903. @end example
  4904. If you forget the @code{bash} (or similar) package, @command{singularity
  4905. run} and @command{singularity exec} will fail with an unhelpful ``no
  4906. such file or directory'' message.
  4907. @end quotation
  4908. @end table
  4909. @cindex relocatable binaries
  4910. @item --relocatable
  4911. @itemx -R
  4912. Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
  4913. anywhere in the file system hierarchy and run from there.
  4914. When this option is passed once, the resulting binaries require support for
  4915. @dfn{user namespaces} in the kernel Linux; when passed
  4916. @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
  4917. PRoot support, can be thought of as the abbreviation of ``Really
  4918. Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
  4919. other techniques if user namespaces are unavailable, and essentially
  4920. work anywhere---see below for the implications.
  4921. For example, if you create a pack containing Bash with:
  4922. @example
  4923. guix pack -RR -S /mybin=bin bash
  4924. @end example
  4925. @noindent
  4926. ...@: you can copy that pack to a machine that lacks Guix, and from your
  4927. home directory as a normal user, run:
  4928. @example
  4929. tar xf pack.tar.gz
  4930. ./mybin/sh
  4931. @end example
  4932. @noindent
  4933. In that shell, if you type @code{ls /gnu/store}, you'll notice that
  4934. @file{/gnu/store} shows up and contains all the dependencies of
  4935. @code{bash}, even though the machine actually lacks @file{/gnu/store}
  4936. altogether! That is probably the simplest way to deploy Guix-built
  4937. software on a non-Guix machine.
  4938. @quotation Note
  4939. By default, relocatable binaries rely on the @dfn{user namespace} feature of
  4940. the kernel Linux, which allows unprivileged users to mount or change root.
  4941. Old versions of Linux did not support it, and some GNU/Linux distributions
  4942. turn it off.
  4943. To produce relocatable binaries that work even in the absence of user
  4944. namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
  4945. case, binaries will try user namespace support and fall back to another
  4946. @dfn{execution engine} if user namespaces are not supported. The
  4947. following execution engines are supported:
  4948. @table @code
  4949. @item default
  4950. Try user namespaces and fall back to PRoot if user namespaces are not
  4951. supported (see below).
  4952. @item performance
  4953. Try user namespaces and fall back to Fakechroot if user namespaces are
  4954. not supported (see below).
  4955. @item userns
  4956. Run the program through user namespaces and abort if they are not
  4957. supported.
  4958. @item proot
  4959. Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
  4960. provides the necessary
  4961. support for file system virtualization. It achieves that by using the
  4962. @code{ptrace} system call on the running program. This approach has the
  4963. advantage to work without requiring special kernel support, but it incurs
  4964. run-time overhead every time a system call is made.
  4965. @item fakechroot
  4966. Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
  4967. Fakechroot} virtualizes file system accesses by intercepting calls to C
  4968. library functions such as @code{open}, @code{stat}, @code{exec}, and so
  4969. on. Unlike PRoot, it incurs very little overhead. However, it does not
  4970. always work: for example, some file system accesses made from within the
  4971. C library are not intercepted, and file system accesses made @i{via}
  4972. direct syscalls are not intercepted either, leading to erratic behavior.
  4973. @end table
  4974. @vindex GUIX_EXECUTION_ENGINE
  4975. When running a wrapped program, you can explicitly request one of the
  4976. execution engines listed above by setting the
  4977. @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
  4978. @end quotation
  4979. @cindex entry point, for Docker images
  4980. @item --entry-point=@var{command}
  4981. Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
  4982. format supports it---currently @code{docker} and @code{squashfs} (Singularity)
  4983. support it. @var{command} must be relative to the profile contained in the
  4984. pack.
  4985. The entry point specifies the command that tools like @code{docker run} or
  4986. @code{singularity run} automatically start by default. For example, you can
  4987. do:
  4988. @example
  4989. guix pack -f docker --entry-point=bin/guile guile
  4990. @end example
  4991. The resulting pack can easily be loaded and @code{docker run} with no extra
  4992. arguments will spawn @code{bin/guile}:
  4993. @example
  4994. docker load -i pack.tar.gz
  4995. docker run @var{image-id}
  4996. @end example
  4997. @item --expression=@var{expr}
  4998. @itemx -e @var{expr}
  4999. Consider the package @var{expr} evaluates to.
  5000. This has the same purpose as the same-named option in @command{guix
  5001. build} (@pxref{Additional Build Options, @option{--expression} in
  5002. @command{guix build}}).
  5003. @item --manifest=@var{file}
  5004. @itemx -m @var{file}
  5005. Use the packages contained in the manifest object returned by the Scheme
  5006. code in @var{file}. This option can be repeated several times, in which
  5007. case the manifests are concatenated.
  5008. This has a similar purpose as the same-named option in @command{guix
  5009. package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
  5010. same manifest files. It allows you to define a collection of packages
  5011. once and use it both for creating profiles and for creating archives
  5012. for use on machines that do not have Guix installed. Note that you can
  5013. specify @emph{either} a manifest file @emph{or} a list of packages,
  5014. but not both.
  5015. @item --system=@var{system}
  5016. @itemx -s @var{system}
  5017. Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
  5018. the system type of the build host.
  5019. @item --target=@var{triplet}
  5020. @cindex cross-compilation
  5021. Cross-build for @var{triplet}, which must be a valid GNU triplet, such
  5022. as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
  5023. configuration triplets,, autoconf, Autoconf}).
  5024. @item --compression=@var{tool}
  5025. @itemx -C @var{tool}
  5026. Compress the resulting tarball using @var{tool}---one of @code{gzip},
  5027. @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
  5028. compression.
  5029. @item --symlink=@var{spec}
  5030. @itemx -S @var{spec}
  5031. Add the symlinks specified by @var{spec} to the pack. This option can
  5032. appear several times.
  5033. @var{spec} has the form @code{@var{source}=@var{target}}, where
  5034. @var{source} is the symlink that will be created and @var{target} is the
  5035. symlink target.
  5036. For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
  5037. symlink pointing to the @file{bin} sub-directory of the profile.
  5038. @item --save-provenance
  5039. Save provenance information for the packages passed on the command line.
  5040. Provenance information includes the URL and commit of the channels in use
  5041. (@pxref{Channels}).
  5042. Provenance information is saved in the
  5043. @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
  5044. usual package metadata---the name and version of each package, their
  5045. propagated inputs, and so on. It is useful information to the recipient of
  5046. the pack, who then knows how the pack was (supposedly) obtained.
  5047. This option is not enabled by default because, like timestamps, provenance
  5048. information contributes nothing to the build process. In other words, there
  5049. is an infinity of channel URLs and commit IDs that can lead to the same pack.
  5050. Recording such ``silent'' metadata in the output thus potentially breaks the
  5051. source-to-binary bitwise reproducibility property.
  5052. @item --root=@var{file}
  5053. @itemx -r @var{file}
  5054. @cindex garbage collector root, for packs
  5055. Make @var{file} a symlink to the resulting pack, and register it as a garbage
  5056. collector root.
  5057. @item --localstatedir
  5058. @itemx --profile-name=@var{name}
  5059. Include the ``local state directory'', @file{/var/guix}, in the resulting
  5060. pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
  5061. profile---by default @var{name} is @code{guix-profile}, which corresponds to
  5062. @file{~root/.guix-profile}.
  5063. @file{/var/guix} contains the store database (@pxref{The Store}) as well
  5064. as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
  5065. the pack means that the store is ``complete'' and manageable by Guix;
  5066. not providing it pack means that the store is ``dead'': items cannot be
  5067. added to it or removed from it after extraction of the pack.
  5068. One use case for this is the Guix self-contained binary tarball
  5069. (@pxref{Binary Installation}).
  5070. @item --derivation
  5071. @itemx -d
  5072. Print the name of the derivation that builds the pack.
  5073. @item --bootstrap
  5074. Use the bootstrap binaries to build the pack. This option is only
  5075. useful to Guix developers.
  5076. @end table
  5077. In addition, @command{guix pack} supports all the common build options
  5078. (@pxref{Common Build Options}) and all the package transformation
  5079. options (@pxref{Package Transformation Options}).
  5080. @node The GCC toolchain
  5081. @section The GCC toolchain
  5082. @cindex GCC
  5083. @cindex ld-wrapper
  5084. @cindex linker wrapper
  5085. @cindex toolchain, for C development
  5086. @cindex toolchain, for Fortran development
  5087. If you need a complete toolchain for compiling and linking C or C++
  5088. source code, use the @code{gcc-toolchain} package. This package
  5089. provides a complete GCC toolchain for C/C++ development, including GCC
  5090. itself, the GNU C Library (headers and binaries, plus debugging symbols
  5091. in the @code{debug} output), Binutils, and a linker wrapper.
  5092. The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
  5093. passed to the linker, add corresponding @code{-rpath} arguments, and
  5094. invoke the actual linker with this new set of arguments. You can instruct the
  5095. wrapper to refuse to link against libraries not in the store by setting the
  5096. @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
  5097. The package @code{gfortran-toolchain} provides a complete GCC toolchain
  5098. for Fortran development. For other languages, please use
  5099. @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
  5100. @node Invoking guix git authenticate
  5101. @section Invoking @command{guix git authenticate}
  5102. The @command{guix git authenticate} command authenticates a Git checkout
  5103. following the same rule as for channels (@pxref{channel-authentication,
  5104. channel authentication}). That is, starting from a given commit, it
  5105. ensures that all subsequent commits are signed by an OpenPGP key whose
  5106. fingerprint appears in the @file{.guix-authorizations} file of its
  5107. parent commit(s).
  5108. You will find this command useful if you maintain a channel. But in
  5109. fact, this authentication mechanism is useful in a broader context, so
  5110. you might want to use it for Git repositories that have nothing to do
  5111. with Guix.
  5112. The general syntax is:
  5113. @example
  5114. guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
  5115. @end example
  5116. By default, this command authenticates the Git checkout in the current
  5117. directory; it outputs nothing and exits with exit code zero on success
  5118. and non-zero on failure. @var{commit} above denotes the first commit
  5119. where authentication takes place, and @var{signer} is the OpenPGP
  5120. fingerprint of public key used to sign @var{commit}. Together, they
  5121. form a ``channel introduction'' (@pxref{channel-authentication, channel
  5122. introduction}). The options below allow you to fine-tune the process.
  5123. @table @code
  5124. @item --repository=@var{directory}
  5125. @itemx -r @var{directory}
  5126. Open the Git repository in @var{directory} instead of the current
  5127. directory.
  5128. @item --keyring=@var{reference}
  5129. @itemx -k @var{reference}
  5130. Load OpenPGP keyring from @var{reference}, the reference of a branch
  5131. such as @code{origin/keyring} or @code{my-keyring}. The branch must
  5132. contain OpenPGP public keys in @file{.key} files, either in binary form
  5133. or ``ASCII-armored''. By default the keyring is loaded from the branch
  5134. named @code{keyring}.
  5135. @item --stats
  5136. Display commit signing statistics upon completion.
  5137. @item --cache-key=@var{key}
  5138. Previously-authenticated commits are cached in a file under
  5139. @file{~/.cache/guix/authentication}. This option forces the cache to be
  5140. stored in file @var{key} in that directory.
  5141. @item --historical-authorizations=@var{file}
  5142. By default, any commit whose parent commit(s) lack the
  5143. @file{.guix-authorizations} file is considered inauthentic. In
  5144. contrast, this option considers the authorizations in @var{file} for any
  5145. commit that lacks @file{.guix-authorizations}. The format of @var{file}
  5146. is the same as that of @file{.guix-authorizations}
  5147. (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
  5148. @end table
  5149. @c *********************************************************************
  5150. @node Programming Interface
  5151. @chapter Programming Interface
  5152. GNU Guix provides several Scheme programming interfaces (APIs) to
  5153. define, build, and query packages. The first interface allows users to
  5154. write high-level package definitions. These definitions refer to
  5155. familiar packaging concepts, such as the name and version of a package,
  5156. its build system, and its dependencies. These definitions can then be
  5157. turned into concrete build actions.
  5158. Build actions are performed by the Guix daemon, on behalf of users. In a
  5159. standard setup, the daemon has write access to the store---the
  5160. @file{/gnu/store} directory---whereas users do not. The recommended
  5161. setup also has the daemon perform builds in chroots, under specific
  5162. build users, to minimize interference with the rest of the system.
  5163. @cindex derivation
  5164. Lower-level APIs are available to interact with the daemon and the
  5165. store. To instruct the daemon to perform a build action, users actually
  5166. provide it with a @dfn{derivation}. A derivation is a low-level
  5167. representation of the build actions to be taken, and the environment in
  5168. which they should occur---derivations are to package definitions what
  5169. assembly is to C programs. The term ``derivation'' comes from the fact
  5170. that build results @emph{derive} from them.
  5171. This chapter describes all these APIs in turn, starting from high-level
  5172. package definitions.
  5173. @menu
  5174. * Package Modules:: Packages from the programmer's viewpoint.
  5175. * Defining Packages:: Defining new packages.
  5176. * Defining Package Variants:: Customizing packages.
  5177. * Build Systems:: Specifying how packages are built.
  5178. * Build Phases:: Phases of the build process of a package.
  5179. * Build Utilities:: Helpers for your package definitions and more.
  5180. * The Store:: Manipulating the package store.
  5181. * Derivations:: Low-level interface to package derivations.
  5182. * The Store Monad:: Purely functional interface to the store.
  5183. * G-Expressions:: Manipulating build expressions.
  5184. * Invoking guix repl:: Programming Guix in Guile
  5185. * Defining Substituters:: Defining new substitution methods.
  5186. @end menu
  5187. @node Package Modules
  5188. @section Package Modules
  5189. From a programming viewpoint, the package definitions of the
  5190. GNU distribution are provided by Guile modules in the @code{(gnu packages
  5191. @dots{})} name space@footnote{Note that packages under the @code{(gnu
  5192. packages @dots{})} module name space are not necessarily ``GNU
  5193. packages''. This module naming scheme follows the usual Guile module
  5194. naming convention: @code{gnu} means that these modules are distributed
  5195. as part of the GNU system, and @code{packages} identifies modules that
  5196. define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
  5197. Reference Manual}). For instance, the @code{(gnu packages emacs)}
  5198. module exports a variable named @code{emacs}, which is bound to a
  5199. @code{<package>} object (@pxref{Defining Packages}).
  5200. The @code{(gnu packages @dots{})} module name space is
  5201. automatically scanned for packages by the command-line tools. For
  5202. instance, when running @code{guix install emacs}, all the @code{(gnu
  5203. packages @dots{})} modules are scanned until one that exports a package
  5204. object whose name is @code{emacs} is found. This package search
  5205. facility is implemented in the @code{(gnu packages)} module.
  5206. @cindex customization, of packages
  5207. @cindex package module search path
  5208. Users can store package definitions in modules with different
  5209. names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
  5210. name and module name must match. For instance, the @code{(my-packages
  5211. emacs)} module must be stored in a @file{my-packages/emacs.scm} file
  5212. relative to the load path specified with @option{--load-path} or
  5213. @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
  5214. guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
  5215. these package definitions visible to the user interfaces:
  5216. @enumerate
  5217. @item
  5218. By adding the directory containing your package modules to the search path
  5219. with the @code{-L} flag of @command{guix package} and other commands
  5220. (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
  5221. environment variable described below.
  5222. @item
  5223. By defining a @dfn{channel} and configuring @command{guix pull} so that it
  5224. pulls from it. A channel is essentially a Git repository containing package
  5225. modules. @xref{Channels}, for more information on how to define and use
  5226. channels.
  5227. @end enumerate
  5228. @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
  5229. @defvr {Environment Variable} GUIX_PACKAGE_PATH
  5230. This is a colon-separated list of directories to search for additional
  5231. package modules. Directories listed in this variable take precedence
  5232. over the own modules of the distribution.
  5233. @end defvr
  5234. The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
  5235. each package is built based solely on other packages in the
  5236. distribution. The root of this dependency graph is a small set of
  5237. @dfn{bootstrap binaries}, provided by the @code{(gnu packages
  5238. bootstrap)} module. For more information on bootstrapping,
  5239. @pxref{Bootstrapping}.
  5240. @node Defining Packages
  5241. @section Defining Packages
  5242. The high-level interface to package definitions is implemented in the
  5243. @code{(guix packages)} and @code{(guix build-system)} modules. As an
  5244. example, the package definition, or @dfn{recipe}, for the GNU Hello
  5245. package looks like this:
  5246. @lisp
  5247. (define-module (gnu packages hello)
  5248. #:use-module (guix packages)
  5249. #:use-module (guix download)
  5250. #:use-module (guix build-system gnu)
  5251. #:use-module (guix licenses)
  5252. #:use-module (gnu packages gawk))
  5253. (define-public hello
  5254. (package
  5255. (name "hello")
  5256. (version "2.10")
  5257. (source (origin
  5258. (method url-fetch)
  5259. (uri (string-append "mirror://gnu/hello/hello-" version
  5260. ".tar.gz"))
  5261. (sha256
  5262. (base32
  5263. "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
  5264. (build-system gnu-build-system)
  5265. (arguments '(#:configure-flags '("--enable-silent-rules")))
  5266. (inputs `(("gawk" ,gawk)))
  5267. (synopsis "Hello, GNU world: An example GNU package")
  5268. (description "Guess what GNU Hello prints!")
  5269. (home-page "https://www.gnu.org/software/hello/")
  5270. (license gpl3+)))
  5271. @end lisp
  5272. @noindent
  5273. Without being a Scheme expert, the reader may have guessed the meaning
  5274. of the various fields here. This expression binds the variable
  5275. @code{hello} to a @code{<package>} object, which is essentially a record
  5276. (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
  5277. This package object can be inspected using procedures found in the
  5278. @code{(guix packages)} module; for instance, @code{(package-name hello)}
  5279. returns---surprise!---@code{"hello"}.
  5280. With luck, you may be able to import part or all of the definition of
  5281. the package you are interested in from another repository, using the
  5282. @code{guix import} command (@pxref{Invoking guix import}).
  5283. In the example above, @code{hello} is defined in a module of its own,
  5284. @code{(gnu packages hello)}. Technically, this is not strictly
  5285. necessary, but it is convenient to do so: all the packages defined in
  5286. modules under @code{(gnu packages @dots{})} are automatically known to
  5287. the command-line tools (@pxref{Package Modules}).
  5288. There are a few points worth noting in the above package definition:
  5289. @itemize
  5290. @item
  5291. The @code{source} field of the package is an @code{<origin>} object
  5292. (@pxref{origin Reference}, for the complete reference).
  5293. Here, the @code{url-fetch} method from @code{(guix download)} is used,
  5294. meaning that the source is a file to be downloaded over FTP or HTTP.
  5295. The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
  5296. the GNU mirrors defined in @code{(guix download)}.
  5297. The @code{sha256} field specifies the expected SHA256 hash of the file
  5298. being downloaded. It is mandatory, and allows Guix to check the
  5299. integrity of the file. The @code{(base32 @dots{})} form introduces the
  5300. base32 representation of the hash. You can obtain this information with
  5301. @code{guix download} (@pxref{Invoking guix download}) and @code{guix
  5302. hash} (@pxref{Invoking guix hash}).
  5303. @cindex patches
  5304. When needed, the @code{origin} form can also have a @code{patches} field
  5305. listing patches to be applied, and a @code{snippet} field giving a
  5306. Scheme expression to modify the source code.
  5307. @item
  5308. @cindex GNU Build System
  5309. The @code{build-system} field specifies the procedure to build the
  5310. package (@pxref{Build Systems}). Here, @code{gnu-build-system}
  5311. represents the familiar GNU Build System, where packages may be
  5312. configured, built, and installed with the usual @code{./configure &&
  5313. make && make check && make install} command sequence.
  5314. When you start packaging non-trivial software, you may need tools to
  5315. manipulate those build phases, manipulate files, and so on. @xref{Build
  5316. Utilities}, for more on this.
  5317. @item
  5318. The @code{arguments} field specifies options for the build system
  5319. (@pxref{Build Systems}). Here it is interpreted by
  5320. @code{gnu-build-system} as a request run @file{configure} with the
  5321. @option{--enable-silent-rules} flag.
  5322. @cindex quote
  5323. @cindex quoting
  5324. @findex '
  5325. @findex quote
  5326. What about these quote (@code{'}) characters? They are Scheme syntax to
  5327. introduce a literal list; @code{'} is synonymous with @code{quote}.
  5328. @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
  5329. for details. Here the value of the @code{arguments} field is a list of
  5330. arguments passed to the build system down the road, as with @code{apply}
  5331. (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
  5332. Manual}).
  5333. The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
  5334. (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
  5335. @code{#:configure-flags} is a keyword used to pass a keyword argument
  5336. to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
  5337. Reference Manual}).
  5338. @item
  5339. The @code{inputs} field specifies inputs to the build process---i.e.,
  5340. build-time or run-time dependencies of the package. Here, we define an
  5341. input called @code{"gawk"} whose value is that of the @code{gawk}
  5342. variable; @code{gawk} is itself bound to a @code{<package>} object.
  5343. @cindex backquote (quasiquote)
  5344. @findex `
  5345. @findex quasiquote
  5346. @cindex comma (unquote)
  5347. @findex ,
  5348. @findex unquote
  5349. @findex ,@@
  5350. @findex unquote-splicing
  5351. Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
  5352. us to introduce a literal list in the @code{inputs} field, while
  5353. @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
  5354. value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
  5355. Reference Manual}).
  5356. Note that GCC, Coreutils, Bash, and other essential tools do not need to
  5357. be specified as inputs here. Instead, @code{gnu-build-system} takes care
  5358. of ensuring that they are present (@pxref{Build Systems}).
  5359. However, any other dependencies need to be specified in the
  5360. @code{inputs} field. Any dependency not specified here will simply be
  5361. unavailable to the build process, possibly leading to a build failure.
  5362. @end itemize
  5363. @xref{package Reference}, for a full description of possible fields.
  5364. Once a package definition is in place, the
  5365. package may actually be built using the @code{guix build} command-line
  5366. tool (@pxref{Invoking guix build}), troubleshooting any build failures
  5367. you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
  5368. package definition using the @command{guix edit} command
  5369. (@pxref{Invoking guix edit}).
  5370. @xref{Packaging Guidelines}, for
  5371. more information on how to test package definitions, and
  5372. @ref{Invoking guix lint}, for information on how to check a definition
  5373. for style conformance.
  5374. @vindex GUIX_PACKAGE_PATH
  5375. Lastly, @pxref{Channels}, for information
  5376. on how to extend the distribution by adding your own package definitions
  5377. in a ``channel''.
  5378. Finally, updating the package definition to a new upstream version
  5379. can be partly automated by the @command{guix refresh} command
  5380. (@pxref{Invoking guix refresh}).
  5381. Behind the scenes, a derivation corresponding to the @code{<package>}
  5382. object is first computed by the @code{package-derivation} procedure.
  5383. That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
  5384. The build actions it prescribes may then be realized by using the
  5385. @code{build-derivations} procedure (@pxref{The Store}).
  5386. @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
  5387. Return the @code{<derivation>} object of @var{package} for @var{system}
  5388. (@pxref{Derivations}).
  5389. @var{package} must be a valid @code{<package>} object, and @var{system}
  5390. must be a string denoting the target system type---e.g.,
  5391. @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
  5392. must be a connection to the daemon, which operates on the store
  5393. (@pxref{The Store}).
  5394. @end deffn
  5395. @noindent
  5396. @cindex cross-compilation
  5397. Similarly, it is possible to compute a derivation that cross-builds a
  5398. package for some other system:
  5399. @deffn {Scheme Procedure} package-cross-derivation @var{store} @
  5400. @var{package} @var{target} [@var{system}]
  5401. Return the @code{<derivation>} object of @var{package} cross-built from
  5402. @var{system} to @var{target}.
  5403. @var{target} must be a valid GNU triplet denoting the target hardware
  5404. and operating system, such as @code{"aarch64-linux-gnu"}
  5405. (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
  5406. @end deffn
  5407. Once you have package definitions, you can easily define @emph{variants}
  5408. of those packages. @xref{Defining Package Variants}, for more on that.
  5409. @menu
  5410. * package Reference:: The package data type.
  5411. * origin Reference:: The origin data type.
  5412. @end menu
  5413. @node package Reference
  5414. @subsection @code{package} Reference
  5415. This section summarizes all the options available in @code{package}
  5416. declarations (@pxref{Defining Packages}).
  5417. @deftp {Data Type} package
  5418. This is the data type representing a package recipe.
  5419. @table @asis
  5420. @item @code{name}
  5421. The name of the package, as a string.
  5422. @item @code{version}
  5423. The version of the package, as a string.
  5424. @item @code{source}
  5425. An object telling how the source code for the package should be
  5426. acquired. Most of the time, this is an @code{origin} object, which
  5427. denotes a file fetched from the Internet (@pxref{origin Reference}). It
  5428. can also be any other ``file-like'' object such as a @code{local-file},
  5429. which denotes a file from the local file system (@pxref{G-Expressions,
  5430. @code{local-file}}).
  5431. @item @code{build-system}
  5432. The build system that should be used to build the package (@pxref{Build
  5433. Systems}).
  5434. @item @code{arguments} (default: @code{'()})
  5435. The arguments that should be passed to the build system. This is a
  5436. list, typically containing sequential keyword-value pairs.
  5437. @item @code{inputs} (default: @code{'()})
  5438. @itemx @code{native-inputs} (default: @code{'()})
  5439. @itemx @code{propagated-inputs} (default: @code{'()})
  5440. @cindex inputs, of packages
  5441. These fields list dependencies of the package. Each one is a list of
  5442. tuples, where each tuple has a label for the input (a string) as its
  5443. first element, a package, origin, or derivation as its second element,
  5444. and optionally the name of the output thereof that should be used, which
  5445. defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
  5446. more on package outputs). For example, the list below specifies three
  5447. inputs:
  5448. @lisp
  5449. `(("libffi" ,libffi)
  5450. ("libunistring" ,libunistring)
  5451. ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
  5452. @end lisp
  5453. @cindex cross compilation, package dependencies
  5454. The distinction between @code{native-inputs} and @code{inputs} is
  5455. necessary when considering cross-compilation. When cross-compiling,
  5456. dependencies listed in @code{inputs} are built for the @emph{target}
  5457. architecture; conversely, dependencies listed in @code{native-inputs}
  5458. are built for the architecture of the @emph{build} machine.
  5459. @code{native-inputs} is typically used to list tools needed at
  5460. build time, but not at run time, such as Autoconf, Automake, pkg-config,
  5461. Gettext, or Bison. @command{guix lint} can report likely mistakes in
  5462. this area (@pxref{Invoking guix lint}).
  5463. @anchor{package-propagated-inputs}
  5464. Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
  5465. specified packages will be automatically installed to profiles
  5466. (@pxref{Features, the role of profiles in Guix}) alongside the package
  5467. they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
  5468. package}}, for information on how @command{guix package} deals with
  5469. propagated inputs).
  5470. For example this is necessary when packaging a C/C++ library that needs
  5471. headers of another library to compile, or when a pkg-config file refers
  5472. to another one @i{via} its @code{Requires} field.
  5473. Another example where @code{propagated-inputs} is useful is for languages
  5474. that lack a facility to record the run-time search path akin to the
  5475. @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
  5476. more. When packaging libraries written in those languages, ensure they
  5477. can find library code they depend on at run time by listing run-time
  5478. dependencies in @code{propagated-inputs} rather than @code{inputs}.
  5479. @item @code{outputs} (default: @code{'("out")})
  5480. The list of output names of the package. @xref{Packages with Multiple
  5481. Outputs}, for typical uses of additional outputs.
  5482. @item @code{native-search-paths} (default: @code{'()})
  5483. @itemx @code{search-paths} (default: @code{'()})
  5484. A list of @code{search-path-specification} objects describing
  5485. search-path environment variables honored by the package.
  5486. @item @code{replacement} (default: @code{#f})
  5487. This must be either @code{#f} or a package object that will be used as a
  5488. @dfn{replacement} for this package. @xref{Security Updates, grafts},
  5489. for details.
  5490. @item @code{synopsis}
  5491. A one-line description of the package.
  5492. @item @code{description}
  5493. A more elaborate description of the package.
  5494. @item @code{license}
  5495. @cindex license, of packages
  5496. The license of the package; a value from @code{(guix licenses)},
  5497. or a list of such values.
  5498. @item @code{home-page}
  5499. The URL to the home-page of the package, as a string.
  5500. @item @code{supported-systems} (default: @code{%supported-systems})
  5501. The list of systems supported by the package, as strings of the form
  5502. @code{architecture-kernel}, for example @code{"x86_64-linux"}.
  5503. @item @code{location} (default: source location of the @code{package} form)
  5504. The source location of the package. It is useful to override this when
  5505. inheriting from another package, in which case this field is not
  5506. automatically corrected.
  5507. @end table
  5508. @end deftp
  5509. @deffn {Scheme Syntax} this-package
  5510. When used in the @emph{lexical scope} of a package field definition, this
  5511. identifier resolves to the package being defined.
  5512. The example below shows how to add a package as a native input of itself when
  5513. cross-compiling:
  5514. @lisp
  5515. (package
  5516. (name "guile")
  5517. ;; ...
  5518. ;; When cross-compiled, Guile, for example, depends on
  5519. ;; a native version of itself. Add it here.
  5520. (native-inputs (if (%current-target-system)
  5521. `(("self" ,this-package))
  5522. '())))
  5523. @end lisp
  5524. It is an error to refer to @code{this-package} outside a package definition.
  5525. @end deffn
  5526. Because packages are regular Scheme objects that capture a complete
  5527. dependency graph and associated build procedures, it is often useful to
  5528. write procedures that take a package and return a modified version
  5529. thereof according to some parameters. Below are a few examples.
  5530. @cindex tool chain, choosing a package's tool chain
  5531. @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
  5532. Return a variant of @var{package} that uses @var{toolchain} instead of
  5533. the default GNU C/C++ toolchain. @var{toolchain} must be a list of
  5534. inputs (label/package tuples) providing equivalent functionality, such
  5535. as the @code{gcc-toolchain} package.
  5536. The example below returns a variant of the @code{hello} package built
  5537. with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
  5538. GNU C Library) instead of the default tool chain:
  5539. @lisp
  5540. (let ((toolchain (specification->package "gcc-toolchain@@10")))
  5541. (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
  5542. @end lisp
  5543. The build tool chain is part of the @dfn{implicit inputs} of
  5544. packages---it's usually not listed as part of the various ``inputs''
  5545. fields and is instead pulled in by the build system. Consequently, this
  5546. procedure works by changing the build system of @var{package} so that it
  5547. pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
  5548. for more on build systems.
  5549. @end deffn
  5550. @node origin Reference
  5551. @subsection @code{origin} Reference
  5552. This section documents @dfn{origins}. An @code{origin} declaration
  5553. specifies data that must be ``produced''---downloaded, usually---and
  5554. whose content hash is known in advance. Origins are primarily used to
  5555. represent the source code of packages (@pxref{Defining Packages}). For
  5556. that reason, the @code{origin} form allows you to declare patches to
  5557. apply to the original source code as well as code snippets to modify it.
  5558. @deftp {Data Type} origin
  5559. This is the data type representing a source code origin.
  5560. @table @asis
  5561. @item @code{uri}
  5562. An object containing the URI of the source. The object type depends on
  5563. the @code{method} (see below). For example, when using the
  5564. @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
  5565. values are: a URL represented as a string, or a list thereof.
  5566. @cindex fixed-output derivations, for download
  5567. @item @code{method}
  5568. A monadic procedure that handles the given URI@. The procedure must
  5569. accept at least three arguments: the value of the @code{uri} field and
  5570. the hash algorithm and hash value specified by the @code{hash} field.
  5571. It must return a store item or a derivation in the store monad
  5572. (@pxref{The Store Monad}); most methods return a fixed-output derivation
  5573. (@pxref{Derivations}).
  5574. Commonly used methods include @code{url-fetch}, which fetches data from
  5575. a URL, and @code{git-fetch}, which fetches data from a Git repository
  5576. (see below).
  5577. @item @code{sha256}
  5578. A bytevector containing the SHA-256 hash of the source. This is
  5579. equivalent to providing a @code{content-hash} SHA256 object in the
  5580. @code{hash} field described below.
  5581. @item @code{hash}
  5582. The @code{content-hash} object of the source---see below for how to use
  5583. @code{content-hash}.
  5584. You can obtain this information using @code{guix download}
  5585. (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
  5586. guix hash}).
  5587. @item @code{file-name} (default: @code{#f})
  5588. The file name under which the source code should be saved. When this is
  5589. @code{#f}, a sensible default value will be used in most cases. In case
  5590. the source is fetched from a URL, the file name from the URL will be
  5591. used. For version control checkouts, it is recommended to provide the
  5592. file name explicitly because the default is not very descriptive.
  5593. @item @code{patches} (default: @code{'()})
  5594. A list of file names, origins, or file-like objects (@pxref{G-Expressions,
  5595. file-like objects}) pointing to patches to be applied to the source.
  5596. This list of patches must be unconditional. In particular, it cannot
  5597. depend on the value of @code{%current-system} or
  5598. @code{%current-target-system}.
  5599. @item @code{snippet} (default: @code{#f})
  5600. A G-expression (@pxref{G-Expressions}) or S-expression that will be run
  5601. in the source directory. This is a convenient way to modify the source,
  5602. sometimes more convenient than a patch.
  5603. @item @code{patch-flags} (default: @code{'("-p1")})
  5604. A list of command-line flags that should be passed to the @code{patch}
  5605. command.
  5606. @item @code{patch-inputs} (default: @code{#f})
  5607. Input packages or derivations to the patching process. When this is
  5608. @code{#f}, the usual set of inputs necessary for patching are provided,
  5609. such as GNU@tie{}Patch.
  5610. @item @code{modules} (default: @code{'()})
  5611. A list of Guile modules that should be loaded during the patching
  5612. process and while running the code in the @code{snippet} field.
  5613. @item @code{patch-guile} (default: @code{#f})
  5614. The Guile package that should be used in the patching process. When
  5615. this is @code{#f}, a sensible default is used.
  5616. @end table
  5617. @end deftp
  5618. @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
  5619. Construct a content hash object for the given @var{algorithm}, and with
  5620. @var{value} as its hash value. When @var{algorithm} is omitted, assume
  5621. it is @code{sha256}.
  5622. @var{value} can be a literal string, in which case it is base32-decoded,
  5623. or it can be a bytevector.
  5624. The following forms are all equivalent:
  5625. @lisp
  5626. (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
  5627. (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
  5628. sha256)
  5629. (content-hash (base32
  5630. "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
  5631. (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
  5632. sha256)
  5633. @end lisp
  5634. Technically, @code{content-hash} is currently implemented as a macro.
  5635. It performs sanity checks at macro-expansion time, when possible, such
  5636. as ensuring that @var{value} has the right size for @var{algorithm}.
  5637. @end deftp
  5638. As we have seen above, how exactly the data an origin refers to is
  5639. retrieved is determined by its @code{method} field. The @code{(guix
  5640. download)} module provides the most common method, @code{url-fetch},
  5641. described below.
  5642. @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
  5643. [name] [#:executable? #f]
  5644. Return a fixed-output derivation that fetches data from @var{url} (a
  5645. string, or a list of strings denoting alternate URLs), which is expected
  5646. to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
  5647. the file name is the base name of URL; optionally, @var{name} can
  5648. specify a different file name. When @var{executable?} is true, make the
  5649. downloaded file executable.
  5650. When one of the URL starts with @code{mirror://}, then its host part is
  5651. interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
  5652. Alternatively, when URL starts with @code{file://}, return the
  5653. corresponding file name in the store.
  5654. @end deffn
  5655. Likewise, the @code{(guix git-download)} module defines the
  5656. @code{git-fetch} origin method, which fetches data from a Git version
  5657. control repository, and the @code{git-reference} data type to describe
  5658. the repository and revision to fetch.
  5659. @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
  5660. Return a fixed-output derivation that fetches @var{ref}, a
  5661. @code{<git-reference>} object. The output is expected to have recursive
  5662. hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
  5663. the file name, or a generic name if @code{#f}.
  5664. @end deffn
  5665. @deftp {Data Type} git-reference
  5666. This data type represents a Git reference for @code{git-fetch} to
  5667. retrieve.
  5668. @table @asis
  5669. @item @code{url}
  5670. The URL of the Git repository to clone.
  5671. @item @code{commit}
  5672. This string denotes either the commit to fetch (a hexadecimal string,
  5673. either the full SHA1 commit or a ``short'' commit string; the latter is
  5674. not recommended) or the tag to fetch.
  5675. @item @code{recursive?} (default: @code{#f})
  5676. This Boolean indicates whether to recursively fetch Git sub-modules.
  5677. @end table
  5678. The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
  5679. repository:
  5680. @lisp
  5681. (git-reference
  5682. (url "https://git.savannah.gnu.org/git/hello.git")
  5683. (commit "v2.10"))
  5684. @end lisp
  5685. This is equivalent to the reference below, which explicitly names the
  5686. commit:
  5687. @lisp
  5688. (git-reference
  5689. (url "https://git.savannah.gnu.org/git/hello.git")
  5690. (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
  5691. @end lisp
  5692. @end deftp
  5693. For Mercurial repositories, the module @code{(guix hg-download)} defines
  5694. the @code{hg-fetch} origin method and @code{hg-reference} data type for
  5695. support of the Mercurial version control system.
  5696. @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
  5697. [name]
  5698. Return a fixed-output derivation that fetches @var{ref}, a
  5699. @code{<hg-reference>} object. The output is expected to have recursive
  5700. hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
  5701. the file name, or a generic name if @code{#false}.
  5702. @end deffn
  5703. @node Defining Package Variants
  5704. @section Defining Package Variants
  5705. @cindex customizing packages
  5706. @cindex variants, of packages
  5707. One of the nice things with Guix is that, given a package definition,
  5708. you can easily @emph{derive} variants of that package---for a different
  5709. upstream version, with different dependencies, different compilation
  5710. options, and so on. Some of these custom packages can be defined
  5711. straight from the command line (@pxref{Package Transformation Options}).
  5712. This section describes how to define package variants in code. This can
  5713. be useful in ``manifests'' (@pxref{profile-manifest,
  5714. @option{--manifest}}) and in your own package collection
  5715. (@pxref{Creating a Channel}), among others!
  5716. @cindex inherit, for package definitions
  5717. As discussed earlier, packages are first-class objects in the Scheme
  5718. language. The @code{(guix packages)} module provides the @code{package}
  5719. construct to define new package objects (@pxref{package Reference}).
  5720. The easiest way to define a package variant is using the @code{inherit}
  5721. keyword together with @code{package}. This allows you to inherit from a
  5722. package definition while overriding the fields you want.
  5723. For example, given the @code{hello} variable, which contains a
  5724. definition for the current version of GNU@tie{}Hello, here's how you
  5725. would define a variant for version 2.2 (released in 2006, it's
  5726. vintage!):
  5727. @lisp
  5728. (use-modules (gnu packages base)) ;for 'hello'
  5729. (define hello-2.2
  5730. (package
  5731. (inherit hello)
  5732. (version "2.2")
  5733. (source (origin
  5734. (method url-fetch)
  5735. (uri (string-append "mirror://gnu/hello/hello-" version
  5736. ".tar.gz"))
  5737. (sha256
  5738. (base32
  5739. "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
  5740. @end lisp
  5741. The example above corresponds to what the @option{--with-source} package
  5742. transformation option does. Essentially @code{hello-2.2} preserves all
  5743. the fields of @code{hello}, except @code{version} and @code{source},
  5744. which it overrides. Note that the original @code{hello} variable is
  5745. still there, in the @code{(gnu packages base)} module, unchanged. When
  5746. you define a custom package like this, you are really @emph{adding} a
  5747. new package definition; the original one remains available.
  5748. You can just as well define variants with a different set of
  5749. dependencies than the original package. For example, the default
  5750. @code{gdb} package depends on @code{guile}, but since that is an
  5751. optional dependency, you can define a variant that removes that
  5752. dependency like so:
  5753. @lisp
  5754. (use-modules (gnu packages gdb) ;for 'gdb'
  5755. (srfi srfi-1)) ;for 'alist-delete'
  5756. (define gdb-sans-guile
  5757. (package
  5758. (inherit gdb)
  5759. (inputs (alist-delete "guile"
  5760. (package-inputs gdb)))))
  5761. @end lisp
  5762. The @code{alist-delete} call above removes the tuple from the
  5763. @code{inputs} field that has @code{"guile"} as its first element
  5764. (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
  5765. Manual}).
  5766. In some cases, you may find it useful to write functions
  5767. (``procedures'', in Scheme parlance) that return a package based on some
  5768. parameters. For example, consider the @code{luasocket} library for the
  5769. Lua programming language. We want to create @code{luasocket} packages
  5770. for major versions of Lua. One way to do that is to define a procedure
  5771. that takes a Lua package and returns a @code{luasocket} package that
  5772. depends on it:
  5773. @lisp
  5774. (define (make-lua-socket name lua)
  5775. ;; Return a luasocket package built with LUA.
  5776. (package
  5777. (name name)
  5778. (version "3.0")
  5779. ;; several fields omitted
  5780. (inputs
  5781. `(("lua" ,lua)))
  5782. (synopsis "Socket library for Lua")))
  5783. (define-public lua5.1-socket
  5784. (make-lua-socket "lua5.1-socket" lua-5.1))
  5785. (define-public lua5.2-socket
  5786. (make-lua-socket "lua5.2-socket" lua-5.2))
  5787. @end lisp
  5788. Here we have defined packages @code{lua5.1-socket} and
  5789. @code{lua5.2-socket} by calling @code{make-lua-socket} with different
  5790. arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
  5791. more info on procedures. Having top-level public definitions for these
  5792. two packages means that they can be referred to from the command line
  5793. (@pxref{Package Modules}).
  5794. @cindex package transformations
  5795. These are pretty simple package variants. As a convenience, the
  5796. @code{(guix transformations)} module provides a high-level interface
  5797. that directly maps to the more sophisticated package transformation
  5798. options (@pxref{Package Transformation Options}):
  5799. @deffn {Scheme Procedure} options->transformation @var{opts}
  5800. Return a procedure that, when passed an object to build (package,
  5801. derivation, etc.), applies the transformations specified by @var{opts} and returns
  5802. the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
  5803. @lisp
  5804. ((with-branch . "guile-gcrypt=master")
  5805. (without-tests . "libgcrypt"))
  5806. @end lisp
  5807. Each symbol names a transformation and the corresponding string is an argument
  5808. to that transformation.
  5809. @end deffn
  5810. For instance, a manifest equivalent to this command:
  5811. @example
  5812. guix build guix \
  5813. --with-branch=guile-gcrypt=master \
  5814. --with-debug-info=zlib
  5815. @end example
  5816. @noindent
  5817. ... would look like this:
  5818. @lisp
  5819. (use-modules (guix transformations))
  5820. (define transform
  5821. ;; The package transformation procedure.
  5822. (options->transformation
  5823. '((with-branch . "guile-gcrypt=master")
  5824. (with-debug-info . "zlib"))))
  5825. (packages->manifest
  5826. (list (transform (specification->package "guix"))))
  5827. @end lisp
  5828. @cindex input rewriting
  5829. @cindex dependency graph rewriting
  5830. The @code{options->transformation} procedure is convenient, but it's
  5831. perhaps also not as flexible as you may like. How is it implemented?
  5832. The astute reader probably noticed that most package transformation
  5833. options go beyond the superficial changes shown in the first examples of
  5834. this section: they involve @dfn{input rewriting}, whereby the dependency
  5835. graph of a package is rewritten by replacing specific inputs by others.
  5836. Dependency graph rewriting, for the purposes of swapping packages in the
  5837. graph, is what the @code{package-input-rewriting} procedure in
  5838. @code{(guix packages)} implements.
  5839. @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
  5840. [@var{rewrite-name}] [#:deep? #t]
  5841. Return a procedure that, when passed a package, replaces its direct and
  5842. indirect dependencies, including implicit inputs when @var{deep?} is
  5843. true, according to @var{replacements}. @var{replacements} is a list of
  5844. package pairs; the first element of each pair is the package to replace,
  5845. and the second one is the replacement.
  5846. Optionally, @var{rewrite-name} is a one-argument procedure that takes
  5847. the name of a package and returns its new name after rewrite.
  5848. @end deffn
  5849. @noindent
  5850. Consider this example:
  5851. @lisp
  5852. (define libressl-instead-of-openssl
  5853. ;; This is a procedure to replace OPENSSL by LIBRESSL,
  5854. ;; recursively.
  5855. (package-input-rewriting `((,openssl . ,libressl))))
  5856. (define git-with-libressl
  5857. (libressl-instead-of-openssl git))
  5858. @end lisp
  5859. @noindent
  5860. Here we first define a rewriting procedure that replaces @var{openssl}
  5861. with @var{libressl}. Then we use it to define a @dfn{variant} of the
  5862. @var{git} package that uses @var{libressl} instead of @var{openssl}.
  5863. This is exactly what the @option{--with-input} command-line option does
  5864. (@pxref{Package Transformation Options, @option{--with-input}}).
  5865. The following variant of @code{package-input-rewriting} can match packages to
  5866. be replaced by name rather than by identity.
  5867. @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
  5868. Return a procedure that, given a package, applies the given
  5869. @var{replacements} to all the package graph, including implicit inputs
  5870. unless @var{deep?} is false. @var{replacements} is a list of
  5871. spec/procedures pair; each spec is a package specification such as
  5872. @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
  5873. package and returns a replacement for that package.
  5874. @end deffn
  5875. The example above could be rewritten this way:
  5876. @lisp
  5877. (define libressl-instead-of-openssl
  5878. ;; Replace all the packages called "openssl" with LibreSSL.
  5879. (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
  5880. @end lisp
  5881. The key difference here is that, this time, packages are matched by spec and
  5882. not by identity. In other words, any package in the graph that is called
  5883. @code{openssl} will be replaced.
  5884. A more generic procedure to rewrite a package dependency graph is
  5885. @code{package-mapping}: it supports arbitrary changes to nodes in the
  5886. graph.
  5887. @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
  5888. Return a procedure that, given a package, applies @var{proc} to all the packages
  5889. depended on and returns the resulting package. The procedure stops recursion
  5890. when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
  5891. applied to implicit inputs as well.
  5892. @end deffn
  5893. @node Build Systems
  5894. @section Build Systems
  5895. @cindex build system
  5896. Each package definition specifies a @dfn{build system} and arguments for
  5897. that build system (@pxref{Defining Packages}). This @code{build-system}
  5898. field represents the build procedure of the package, as well as implicit
  5899. dependencies of that build procedure.
  5900. Build systems are @code{<build-system>} objects. The interface to
  5901. create and manipulate them is provided by the @code{(guix build-system)}
  5902. module, and actual build systems are exported by specific modules.
  5903. @cindex bag (low-level package representation)
  5904. Under the hood, build systems first compile package objects to
  5905. @dfn{bags}. A @dfn{bag} is like a package, but with less
  5906. ornamentation---in other words, a bag is a lower-level representation of
  5907. a package, which includes all the inputs of that package, including some
  5908. that were implicitly added by the build system. This intermediate
  5909. representation is then compiled to a derivation (@pxref{Derivations}).
  5910. The @code{package-with-c-toolchain} is an example of a way to change the
  5911. implicit inputs that a package's build system pulls in (@pxref{package
  5912. Reference, @code{package-with-c-toolchain}}).
  5913. Build systems accept an optional list of @dfn{arguments}. In package
  5914. definitions, these are passed @i{via} the @code{arguments} field
  5915. (@pxref{Defining Packages}). They are typically keyword arguments
  5916. (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
  5917. Guile Reference Manual}). The value of these arguments is usually
  5918. evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
  5919. by the daemon (@pxref{Derivations}).
  5920. The main build system is @code{gnu-build-system}, which implements the
  5921. standard build procedure for GNU and many other packages. It
  5922. is provided by the @code{(guix build-system gnu)} module.
  5923. @defvr {Scheme Variable} gnu-build-system
  5924. @code{gnu-build-system} represents the GNU Build System, and variants
  5925. thereof (@pxref{Configuration, configuration and makefile conventions,,
  5926. standards, GNU Coding Standards}).
  5927. @cindex build phases
  5928. In a nutshell, packages using it are configured, built, and installed with
  5929. the usual @code{./configure && make && make check && make install}
  5930. command sequence. In practice, a few additional steps are often needed.
  5931. All these steps are split up in separate @dfn{phases},
  5932. notably@footnote{Please see the @code{(guix build gnu-build-system)}
  5933. modules for more details about the build phases.}:
  5934. @table @code
  5935. @item unpack
  5936. Unpack the source tarball, and change the current directory to the
  5937. extracted source tree. If the source is actually a directory, copy it
  5938. to the build tree, and enter that directory.
  5939. @item patch-source-shebangs
  5940. Patch shebangs encountered in source files so they refer to the right
  5941. store file names. For instance, this changes @code{#!/bin/sh} to
  5942. @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
  5943. @item configure
  5944. Run the @file{configure} script with a number of default options, such
  5945. as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
  5946. by the @code{#:configure-flags} argument.
  5947. @item build
  5948. Run @code{make} with the list of flags specified with
  5949. @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
  5950. (the default), build with @code{make -j}.
  5951. @item check
  5952. Run @code{make check}, or some other target specified with
  5953. @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
  5954. @code{#:parallel-tests?} argument is true (the default), run @code{make
  5955. check -j}.
  5956. @item install
  5957. Run @code{make install} with the flags listed in @code{#:make-flags}.
  5958. @item patch-shebangs
  5959. Patch shebangs on the installed executable files.
  5960. @item strip
  5961. Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
  5962. is false), copying them to the @code{debug} output when available
  5963. (@pxref{Installing Debugging Files}).
  5964. @end table
  5965. @vindex %standard-phases
  5966. The build-side module @code{(guix build gnu-build-system)} defines
  5967. @code{%standard-phases} as the default list of build phases.
  5968. @code{%standard-phases} is a list of symbol/procedure pairs, where the
  5969. procedure implements the actual phase.
  5970. @xref{Build Phases}, for more info on build phases and ways to customize
  5971. them.
  5972. In addition, this build system ensures that the ``standard'' environment
  5973. for GNU packages is available. This includes tools such as GCC, libc,
  5974. Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
  5975. build-system gnu)} module for a complete list). We call these the
  5976. @dfn{implicit inputs} of a package, because package definitions do not
  5977. have to mention them.
  5978. @end defvr
  5979. Other @code{<build-system>} objects are defined to support other
  5980. conventions and tools used by free software packages. They inherit most
  5981. of @code{gnu-build-system}, and differ mainly in the set of inputs
  5982. implicitly added to the build process, and in the list of phases
  5983. executed. Some of these build systems are listed below.
  5984. @defvr {Scheme Variable} ant-build-system
  5985. This variable is exported by @code{(guix build-system ant)}. It
  5986. implements the build procedure for Java packages that can be built with
  5987. @url{https://ant.apache.org/, Ant build tool}.
  5988. It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
  5989. provided by the @code{icedtea} package to the set of inputs. Different
  5990. packages can be specified with the @code{#:ant} and @code{#:jdk}
  5991. parameters, respectively.
  5992. When the original package does not provide a suitable Ant build file,
  5993. the parameter @code{#:jar-name} can be used to generate a minimal Ant
  5994. build file @file{build.xml} with tasks to build the specified jar
  5995. archive. In this case the parameter @code{#:source-dir} can be used to
  5996. specify the source sub-directory, defaulting to ``src''.
  5997. The @code{#:main-class} parameter can be used with the minimal ant
  5998. buildfile to specify the main class of the resulting jar. This makes the
  5999. jar file executable. The @code{#:test-include} parameter can be used to
  6000. specify the list of junit tests to run. It defaults to
  6001. @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
  6002. disable some tests. It defaults to @code{(list "**/Abstract*.java")},
  6003. because abstract classes cannot be run as tests.
  6004. The parameter @code{#:build-target} can be used to specify the Ant task
  6005. that should be run during the @code{build} phase. By default the
  6006. ``jar'' task will be run.
  6007. @end defvr
  6008. @defvr {Scheme Variable} android-ndk-build-system
  6009. @cindex Android distribution
  6010. @cindex Android NDK build system
  6011. This variable is exported by @code{(guix build-system android-ndk)}. It
  6012. implements a build procedure for Android NDK (native development kit)
  6013. packages using a Guix-specific build process.
  6014. The build system assumes that packages install their public interface
  6015. (header) files to the subdirectory @file{include} of the @code{out} output and
  6016. their libraries to the subdirectory @file{lib} the @code{out} output.
  6017. It's also assumed that the union of all the dependencies of a package
  6018. has no conflicting files.
  6019. For the time being, cross-compilation is not supported - so right now
  6020. the libraries and header files are assumed to be host tools.
  6021. @end defvr
  6022. @defvr {Scheme Variable} asdf-build-system/source
  6023. @defvrx {Scheme Variable} asdf-build-system/sbcl
  6024. @defvrx {Scheme Variable} asdf-build-system/ecl
  6025. These variables, exported by @code{(guix build-system asdf)}, implement
  6026. build procedures for Common Lisp packages using
  6027. @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
  6028. definition facility for Common Lisp programs and libraries.
  6029. The @code{asdf-build-system/source} system installs the packages in
  6030. source form, and can be loaded using any common lisp implementation, via
  6031. ASDF@. The others, such as @code{asdf-build-system/sbcl}, install binary
  6032. systems in the format which a particular implementation understands.
  6033. These build systems can also be used to produce executable programs, or
  6034. lisp images which contain a set of packages pre-loaded.
  6035. The build system uses naming conventions. For binary packages, the
  6036. package name should be prefixed with the lisp implementation, such as
  6037. @code{sbcl-} for @code{asdf-build-system/sbcl}.
  6038. Additionally, the corresponding source package should be labeled using
  6039. the same convention as python packages (see @ref{Python Modules}), using
  6040. the @code{cl-} prefix.
  6041. In order to create executable programs and images, the build-side
  6042. procedures @code{build-program} and @code{build-image} can be used.
  6043. They should be called in a build phase after the
  6044. @code{create-asdf-configuration} phase, so that the system which was
  6045. just built can be used within the resulting image. @code{build-program}
  6046. requires a list of Common Lisp expressions to be passed as the
  6047. @code{#:entry-program} argument.
  6048. By default, all the @file{.asd} files present in the sources are read to
  6049. find system definitions. The @code{#:asd-files} parameter can be used
  6050. to specify the list of @file{.asd} files to read. Furthermore, if the
  6051. package defines a system for its tests in a separate file, it will be
  6052. loaded before the tests are run if it is specified by the
  6053. @code{#:test-asd-file} parameter. If it is not set, the files
  6054. @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
  6055. and @code{test.asd} will be tried if they exist.
  6056. If for some reason the package must be named in a different way than the
  6057. naming conventions suggest, or if several systems must be compiled, the
  6058. @code{#:asd-systems} parameter can be used to specify the list of system
  6059. names.
  6060. @end defvr
  6061. @defvr {Scheme Variable} cargo-build-system
  6062. @cindex Rust programming language
  6063. @cindex Cargo (Rust build system)
  6064. This variable is exported by @code{(guix build-system cargo)}. It
  6065. supports builds of packages using Cargo, the build tool of the
  6066. @uref{https://www.rust-lang.org, Rust programming language}.
  6067. It adds @code{rustc} and @code{cargo} to the set of inputs.
  6068. A different Rust package can be specified with the @code{#:rust} parameter.
  6069. Regular cargo dependencies should be added to the package definition via the
  6070. @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
  6071. spec can be a package or a source definition. Note that the spec must
  6072. evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
  6073. file at its root, or it will be ignored. Similarly, cargo dev-dependencies
  6074. should be added to the package definition via the
  6075. @code{#:cargo-development-inputs} parameter.
  6076. In its @code{configure} phase, this build system will make any source inputs
  6077. specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
  6078. parameters available to cargo. It will also remove an included
  6079. @code{Cargo.lock} file to be recreated by @code{cargo} during the
  6080. @code{build} phase. The @code{install} phase installs the binaries
  6081. defined by the crate.
  6082. @end defvr
  6083. @defvr {Scheme Variable} chicken-build-system
  6084. This variable is exported by @code{(guix build-system chicken)}. It
  6085. builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
  6086. ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
  6087. gets compiled by a C compiler, in this case GCC.
  6088. This build system adds @code{chicken} to the package inputs, as well as
  6089. the packages of @code{gnu-build-system}.
  6090. The build system can't (yet) deduce the egg's name automatically, so just like
  6091. with @code{go-build-system} and its @code{#:import-path}, you should define
  6092. @code{#:egg-name} in the package's @code{arguments} field.
  6093. For example, if you are packaging the @code{srfi-1} egg:
  6094. @lisp
  6095. (arguments '(#:egg-name "srfi-1"))
  6096. @end lisp
  6097. Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
  6098. because CHICKEN doesn't embed absolute references in compiled eggs.
  6099. Test dependencies should go to @code{native-inputs}, as usual.
  6100. @end defvr
  6101. @defvr {Scheme Variable} copy-build-system
  6102. This variable is exported by @code{(guix build-system copy)}. It
  6103. supports builds of simple packages that don't require much compiling,
  6104. mostly just moving files around.
  6105. It adds much of the @code{gnu-build-system} packages to the set of
  6106. inputs. Because of this, the @code{copy-build-system} does not require
  6107. all the boilerplate code often needed for the
  6108. @code{trivial-build-system}.
  6109. To further simplify the file installation process, an
  6110. @code{#:install-plan} argument is exposed to let the packager specify
  6111. which files go where. The install plan is a list of @code{(@var{source}
  6112. @var{target} [@var{filters}])}. @var{filters} are optional.
  6113. @itemize
  6114. @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
  6115. @itemize
  6116. @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
  6117. @item Otherwise install @var{source} as @var{target}.
  6118. @end itemize
  6119. @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
  6120. the trailing slash of @var{target} is implied with the same meaning
  6121. as above.
  6122. @itemize
  6123. @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
  6124. @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
  6125. @code{#:exclude-regexp}, only select files are installed depending on
  6126. the filters. Each filters is specified by a list of strings.
  6127. @itemize
  6128. @item With @code{#:include}, install all the files which the path suffix matches
  6129. at least one of the elements in the given list.
  6130. @item With @code{#:include-regexp}, install all the files which the
  6131. subpaths match at least one of the regular expressions in the given
  6132. list.
  6133. @item The @code{#:exclude} and @code{#:exclude-regexp} filters
  6134. are the complement of their inclusion counterpart. Without @code{#:include} flags,
  6135. install all files but those matching the exclusion filters.
  6136. If both inclusions and exclusions are specified, the exclusions are done
  6137. on top of the inclusions.
  6138. @end itemize
  6139. @end itemize
  6140. In all cases, the paths relative to @var{source} are preserved within
  6141. @var{target}.
  6142. @end itemize
  6143. Examples:
  6144. @itemize
  6145. @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
  6146. @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
  6147. @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
  6148. e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
  6149. @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
  6150. @file{share/my-app/sub/file}.
  6151. @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
  6152. @file{share/my-app/file}.
  6153. @end itemize
  6154. @end defvr
  6155. @cindex Clojure (programming language)
  6156. @cindex simple Clojure build system
  6157. @defvr {Scheme Variable} clojure-build-system
  6158. This variable is exported by @code{(guix build-system clojure)}. It implements
  6159. a simple build procedure for @uref{https://clojure.org/, Clojure} packages
  6160. using plain old @code{compile} in Clojure. Cross-compilation is not supported
  6161. yet.
  6162. It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
  6163. Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
  6164. @code{#:zip} parameters, respectively.
  6165. A list of source directories, test directories and jar names can be specified
  6166. with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
  6167. parameters, respectively. Compile directory and main class can be specified
  6168. with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
  6169. Other parameters are documented below.
  6170. This build system is an extension of @code{ant-build-system}, but with the
  6171. following phases changed:
  6172. @table @code
  6173. @item build
  6174. This phase calls @code{compile} in Clojure to compile source files and runs
  6175. @command{jar} to create jars from both source files and compiled files
  6176. according to the include list and exclude list specified in
  6177. @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
  6178. has priority over the include list. These lists consist of symbols
  6179. representing Clojure libraries or the special keyword @code{#:all} representing
  6180. all Clojure libraries found under the source directories. The parameter
  6181. @code{#:omit-source?} decides if source should be included into the jars.
  6182. @item check
  6183. This phase runs tests according to the include list and exclude list specified
  6184. in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
  6185. meanings are analogous to that of @code{#:aot-include} and
  6186. @code{#:aot-exclude}, except that the special keyword @code{#:all} now
  6187. stands for all Clojure libraries found under the test directories. The
  6188. parameter @code{#:tests?} decides if tests should be run.
  6189. @item install
  6190. This phase installs all jars built previously.
  6191. @end table
  6192. Apart from the above, this build system also contains an additional phase:
  6193. @table @code
  6194. @item install-doc
  6195. This phase installs all top-level files with base name matching
  6196. @code{%doc-regex}. A different regex can be specified with the
  6197. @code{#:doc-regex} parameter. All files (recursively) inside the documentation
  6198. directories specified in @code{#:doc-dirs} are installed as well.
  6199. @end table
  6200. @end defvr
  6201. @defvr {Scheme Variable} cmake-build-system
  6202. This variable is exported by @code{(guix build-system cmake)}. It
  6203. implements the build procedure for packages using the
  6204. @url{https://www.cmake.org, CMake build tool}.
  6205. It automatically adds the @code{cmake} package to the set of inputs.
  6206. Which package is used can be specified with the @code{#:cmake}
  6207. parameter.
  6208. The @code{#:configure-flags} parameter is taken as a list of flags
  6209. passed to the @command{cmake} command. The @code{#:build-type}
  6210. parameter specifies in abstract terms the flags passed to the compiler;
  6211. it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
  6212. debugging information''), which roughly means that code is compiled with
  6213. @code{-O2 -g}, as is the case for Autoconf-based packages by default.
  6214. @end defvr
  6215. @defvr {Scheme Variable} dune-build-system
  6216. This variable is exported by @code{(guix build-system dune)}. It
  6217. supports builds of packages using @uref{https://dune.build/, Dune}, a build
  6218. tool for the OCaml programming language. It is implemented as an extension
  6219. of the @code{ocaml-build-system} which is described below. As such, the
  6220. @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
  6221. system.
  6222. It automatically adds the @code{dune} package to the set of inputs.
  6223. Which package is used can be specified with the @code{#:dune}
  6224. parameter.
  6225. There is no @code{configure} phase because dune packages typically don't
  6226. need to be configured. The @code{#:build-flags} parameter is taken as a
  6227. list of flags passed to the @code{dune} command during the build.
  6228. The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
  6229. command instead of the more recent @code{dune} command while building
  6230. a package. Its default value is @code{#f}.
  6231. The @code{#:package} parameter can be passed to specify a package name, which
  6232. is useful when a package contains multiple packages and you want to build
  6233. only one of them. This is equivalent to passing the @code{-p} argument to
  6234. @code{dune}.
  6235. @end defvr
  6236. @defvr {Scheme Variable} go-build-system
  6237. This variable is exported by @code{(guix build-system go)}. It
  6238. implements a build procedure for Go packages using the standard
  6239. @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
  6240. Go build mechanisms}.
  6241. The user is expected to provide a value for the key @code{#:import-path}
  6242. and, in some cases, @code{#:unpack-path}. The
  6243. @url{https://golang.org/doc/code.html#ImportPaths, import path}
  6244. corresponds to the file system path expected by the package's build
  6245. scripts and any referring packages, and provides a unique way to
  6246. refer to a Go package. It is typically based on a combination of the
  6247. package source code's remote URI and file system hierarchy structure. In
  6248. some cases, you will need to unpack the package's source code to a
  6249. different directory structure than the one indicated by the import path,
  6250. and @code{#:unpack-path} should be used in such cases.
  6251. Packages that provide Go libraries should install their source code into
  6252. the built output. The key @code{#:install-source?}, which defaults to
  6253. @code{#t}, controls whether or not the source code is installed. It can
  6254. be set to @code{#f} for packages that only provide executable files.
  6255. @end defvr
  6256. @defvr {Scheme Variable} glib-or-gtk-build-system
  6257. This variable is exported by @code{(guix build-system glib-or-gtk)}. It
  6258. is intended for use with packages making use of GLib or GTK+.
  6259. This build system adds the following two phases to the ones defined by
  6260. @code{gnu-build-system}:
  6261. @table @code
  6262. @item glib-or-gtk-wrap
  6263. The phase @code{glib-or-gtk-wrap} ensures that programs in
  6264. @file{bin/} are able to find GLib ``schemas'' and
  6265. @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
  6266. modules}. This is achieved by wrapping the programs in launch scripts
  6267. that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
  6268. environment variables.
  6269. It is possible to exclude specific package outputs from that wrapping
  6270. process by listing their names in the
  6271. @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
  6272. when an output is known not to contain any GLib or GTK+ binaries, and
  6273. where wrapping would gratuitously add a dependency of that output on
  6274. GLib and GTK+.
  6275. @item glib-or-gtk-compile-schemas
  6276. The phase @code{glib-or-gtk-compile-schemas} makes sure that all
  6277. @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
  6278. GSettings schemas} of GLib are compiled. Compilation is performed by the
  6279. @command{glib-compile-schemas} program. It is provided by the package
  6280. @code{glib:bin} which is automatically imported by the build system.
  6281. The @code{glib} package providing @command{glib-compile-schemas} can be
  6282. specified with the @code{#:glib} parameter.
  6283. @end table
  6284. Both phases are executed after the @code{install} phase.
  6285. @end defvr
  6286. @defvr {Scheme Variable} guile-build-system
  6287. This build system is for Guile packages that consist exclusively of Scheme
  6288. code and that are so lean that they don't even have a makefile, let alone a
  6289. @file{configure} script. It compiles Scheme code using @command{guild
  6290. compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
  6291. installs the @file{.scm} and @file{.go} files in the right place. It also
  6292. installs documentation.
  6293. This build system supports cross-compilation by using the
  6294. @option{--target} option of @samp{guild compile}.
  6295. Packages built with @code{guile-build-system} must provide a Guile package in
  6296. their @code{native-inputs} field.
  6297. @end defvr
  6298. @defvr {Scheme Variable} julia-build-system
  6299. This variable is exported by @code{(guix build-system julia)}. It
  6300. implements the build procedure used by @uref{https://julialang.org/,
  6301. julia} packages, which essentially is similar to running @samp{julia -e
  6302. 'using Pkg; Pkg.add(package)'} in an environment where
  6303. @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
  6304. Tests are run by calling @code{/test/runtests.jl}.
  6305. The Julia package name is read from the file @file{Project.toml}. This
  6306. value can be overridden by passing the argument @code{#:julia-file-name}
  6307. (which must be correctly capitalized).
  6308. For packages requiring shared library dependencies, you may need to write the
  6309. @file{/deps/deps.jl} file manually. It's usually a line of @code{const
  6310. variable = /gnu/store/library.so} for each dependency, plus a void function
  6311. @code{check_deps() = nothing}.
  6312. Some older packages that aren't using @file{Package.toml} yet, will require
  6313. this file to be created, too. The function @code{julia-create-package-toml}
  6314. helps creating the file. You need to pass the outputs and the source of the
  6315. package, it's name (the same as the @code{file-name} parameter), the package
  6316. uuid, the package version, and a list of dependencies specified by their name
  6317. and their uuid.
  6318. @end defvr
  6319. @defvr {Scheme Variable} maven-build-system
  6320. This variable is exported by @code{(guix build-system maven)}. It implements
  6321. a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
  6322. is a dependency and lifecycle management tool for Java. A user of Maven
  6323. specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
  6324. When Maven does not have one of the dependencies or plugins in its repository,
  6325. it will download them and use them to build the package.
  6326. The maven build system ensures that maven will not try to download any
  6327. dependency by running in offline mode. Maven will fail if a dependency is
  6328. missing. Before running Maven, the @file{pom.xml} (and subprojects) are
  6329. modified to specify the version of dependencies and plugins that match the
  6330. versions available in the guix build environment. Dependencies and plugins
  6331. must be installed in the fake maven repository at @file{lib/m2}, and are
  6332. symlinked into a proper repository before maven is run. Maven is instructed
  6333. to use that repository for the build and installs built artifacts there.
  6334. Changed files are copied to the @file{lib/m2} directory of the package output.
  6335. You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
  6336. or let the build system use the default @file{pom.xml} file in the sources.
  6337. In case you need to specify a dependency's version manually, you can use the
  6338. @code{#:local-packages} argument. It takes an association list where the key
  6339. is the groupId of the package and its value is an association list where the
  6340. key is the artifactId of the package and its value is the version you want to
  6341. override in the @file{pom.xml}.
  6342. Some packages use dependencies or plugins that are not useful at runtime nor
  6343. at build time in Guix. You can alter the @file{pom.xml} file to remove them
  6344. using the @code{#:exclude} argument. Its value is an association list where
  6345. the key is the groupId of the plugin or dependency you want to remove, and
  6346. the value is a list of artifactId you want to remove.
  6347. You can override the default @code{jdk} and @code{maven} packages with the
  6348. corresponding argument, @code{#:jdk} and @code{#:maven}.
  6349. The @code{#:maven-plugins} argument is a list of maven plugins used during
  6350. the build, with the same format as the @code{inputs} fields of the package
  6351. declaration. Its default value is @code{(default-maven-plugins)} which is
  6352. also exported.
  6353. @end defvr
  6354. @defvr {Scheme Variable} minify-build-system
  6355. This variable is exported by @code{(guix build-system minify)}. It
  6356. implements a minification procedure for simple JavaScript packages.
  6357. It adds @code{uglify-js} to the set of inputs and uses it to compress
  6358. all JavaScript files in the @file{src} directory. A different minifier
  6359. package can be specified with the @code{#:uglify-js} parameter, but it
  6360. is expected that the package writes the minified code to the standard
  6361. output.
  6362. When the input JavaScript files are not all located in the @file{src}
  6363. directory, the parameter @code{#:javascript-files} can be used to
  6364. specify a list of file names to feed to the minifier.
  6365. @end defvr
  6366. @defvr {Scheme Variable} ocaml-build-system
  6367. This variable is exported by @code{(guix build-system ocaml)}. It implements
  6368. a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
  6369. of choosing the correct set of commands to run for each package. OCaml
  6370. packages can expect many different commands to be run. This build system will
  6371. try some of them.
  6372. When the package has a @file{setup.ml} file present at the top-level, it will
  6373. run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
  6374. @code{ocaml setup.ml -install}. The build system will assume that this file
  6375. was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
  6376. care of setting the prefix and enabling tests if they are not disabled. You
  6377. can pass configure and build flags with the @code{#:configure-flags} and
  6378. @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
  6379. set of flags used to enable tests. The @code{#:use-make?} key can be used to
  6380. bypass this system in the build and install phases.
  6381. When the package has a @file{configure} file, it is assumed that it is a
  6382. hand-made configure script that requires a different argument format than
  6383. in the @code{gnu-build-system}. You can add more flags with the
  6384. @code{#:configure-flags} key.
  6385. When the package has a @file{Makefile} file (or @code{#:use-make?} is
  6386. @code{#t}), it will be used and more flags can be passed to the build and
  6387. install phases with the @code{#:make-flags} key.
  6388. Finally, some packages do not have these files and use a somewhat standard
  6389. location for its build system. In that case, the build system will run
  6390. @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
  6391. providing the path to the required findlib module. Additional flags can
  6392. be passed via the @code{#:build-flags} key. Install is taken care of by
  6393. @command{opam-installer}. In this case, the @code{opam} package must
  6394. be added to the @code{native-inputs} field of the package definition.
  6395. Note that most OCaml packages assume they will be installed in the same
  6396. directory as OCaml, which is not what we want in guix. In particular, they
  6397. will install @file{.so} files in their module's directory, which is usually
  6398. fine because it is in the OCaml compiler directory. In guix though, these
  6399. libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
  6400. variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
  6401. @file{.so} libraries should be installed.
  6402. @end defvr
  6403. @defvr {Scheme Variable} python-build-system
  6404. This variable is exported by @code{(guix build-system python)}. It
  6405. implements the more or less standard build procedure used by Python
  6406. packages, which consists in running @code{python setup.py build} and
  6407. then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
  6408. For packages that install stand-alone Python programs under @code{bin/},
  6409. it takes care of wrapping these programs so that their @env{PYTHONPATH}
  6410. environment variable points to all the Python libraries they depend on.
  6411. Which Python package is used to perform the build can be specified with
  6412. the @code{#:python} parameter. This is a useful way to force a package
  6413. to be built for a specific version of the Python interpreter, which
  6414. might be necessary if the package is only compatible with a single
  6415. interpreter version.
  6416. By default guix calls @code{setup.py} under control of
  6417. @code{setuptools}, much like @command{pip} does. Some packages are not
  6418. compatible with setuptools (and pip), thus you can disable this by
  6419. setting the @code{#:use-setuptools?} parameter to @code{#f}.
  6420. @end defvr
  6421. @defvr {Scheme Variable} perl-build-system
  6422. This variable is exported by @code{(guix build-system perl)}. It
  6423. implements the standard build procedure for Perl packages, which either
  6424. consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
  6425. followed by @code{Build} and @code{Build install}; or in running
  6426. @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
  6427. @code{make} and @code{make install}, depending on which of
  6428. @code{Build.PL} or @code{Makefile.PL} is present in the package
  6429. distribution. Preference is given to the former if both @code{Build.PL}
  6430. and @code{Makefile.PL} exist in the package distribution. This
  6431. preference can be reversed by specifying @code{#t} for the
  6432. @code{#:make-maker?} parameter.
  6433. The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
  6434. passes flags specified by the @code{#:make-maker-flags} or
  6435. @code{#:module-build-flags} parameter, respectively.
  6436. Which Perl package is used can be specified with @code{#:perl}.
  6437. @end defvr
  6438. @defvr {Scheme Variable} renpy-build-system
  6439. This variable is exported by @code{(guix build-system renpy)}. It implements
  6440. the more or less standard build procedure used by Ren'py games, which consists
  6441. of loading @code{#:game} once, thereby creating bytecode for it.
  6442. It further creates a wrapper script in @code{bin/} and a desktop entry in
  6443. @code{share/applications}, both of which can be used to launch the game.
  6444. Which Ren'py package is used can be specified with @code{#:renpy}.
  6445. Games can also be installed in outputs other than ``out'' by using
  6446. @code{#:output}.
  6447. @end defvr
  6448. @defvr {Scheme Variable} qt-build-system
  6449. This variable is exported by @code{(guix build-system qt)}. It
  6450. is intended for use with applications using Qt or KDE.
  6451. This build system adds the following two phases to the ones defined by
  6452. @code{cmake-build-system}:
  6453. @table @code
  6454. @item check-setup
  6455. The phase @code{check-setup} prepares the environment for running
  6456. the checks as commonly used by Qt test programs.
  6457. For now this only sets some environment variables:
  6458. @code{QT_QPA_PLATFORM=offscreen},
  6459. @code{DBUS_FATAL_WARNINGS=0} and
  6460. @code{CTEST_OUTPUT_ON_FAILURE=1}.
  6461. This phase is added before the @code{check} phase.
  6462. It's a separate phase to ease adjusting if necessary.
  6463. @item qt-wrap
  6464. The phase @code{qt-wrap}
  6465. searches for Qt5 plugin paths, QML paths and some XDG in the inputs
  6466. and output. In case some path is found, all programs in the output's
  6467. @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
  6468. are wrapped in scripts defining the necessary environment variables.
  6469. It is possible to exclude specific package outputs from that wrapping process
  6470. by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
  6471. This is useful when an output is known not to contain any Qt binaries, and
  6472. where wrapping would gratuitously add a dependency of that output on Qt, KDE,
  6473. or such.
  6474. This phase is added after the @code{install} phase.
  6475. @end table
  6476. @end defvr
  6477. @defvr {Scheme Variable} r-build-system
  6478. This variable is exported by @code{(guix build-system r)}. It
  6479. implements the build procedure used by @uref{https://r-project.org, R}
  6480. packages, which essentially is little more than running @samp{R CMD
  6481. INSTALL --library=/gnu/store/@dots{}} in an environment where
  6482. @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
  6483. run after installation using the R function
  6484. @code{tools::testInstalledPackage}.
  6485. @end defvr
  6486. @defvr {Scheme Variable} rakudo-build-system
  6487. This variable is exported by @code{(guix build-system rakudo)}. It
  6488. implements the build procedure used by @uref{https://rakudo.org/,
  6489. Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
  6490. package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
  6491. installs the binaries, library files and the resources, as well as wrap
  6492. the files under the @code{bin/} directory. Tests can be skipped by
  6493. passing @code{#f} to the @code{tests?} parameter.
  6494. Which rakudo package is used can be specified with @code{rakudo}.
  6495. Which perl6-tap-harness package used for the tests can be specified with
  6496. @code{#:prove6} or removed by passing @code{#f} to the
  6497. @code{with-prove6?} parameter.
  6498. Which perl6-zef package used for tests and installing can be specified
  6499. with @code{#:zef} or removed by passing @code{#f} to the
  6500. @code{with-zef?} parameter.
  6501. @end defvr
  6502. @defvr {Scheme Variable} texlive-build-system
  6503. This variable is exported by @code{(guix build-system texlive)}. It is
  6504. used to build TeX packages in batch mode with a specified engine. The
  6505. build system sets the @env{TEXINPUTS} variable to find all TeX source
  6506. files in the inputs.
  6507. By default it runs @code{luatex} on all files ending on @code{ins}. A
  6508. different engine and format can be specified with the
  6509. @code{#:tex-format} argument. Different build targets can be specified
  6510. with the @code{#:build-targets} argument, which expects a list of file
  6511. names. The build system adds only @code{texlive-bin} and
  6512. @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
  6513. inputs. Both can be overridden with the arguments @code{#:texlive-bin}
  6514. and @code{#:texlive-latex-base}, respectively.
  6515. The @code{#:tex-directory} parameter tells the build system where to
  6516. install the built files under the texmf tree.
  6517. @end defvr
  6518. @defvr {Scheme Variable} ruby-build-system
  6519. This variable is exported by @code{(guix build-system ruby)}. It
  6520. implements the RubyGems build procedure used by Ruby packages, which
  6521. involves running @code{gem build} followed by @code{gem install}.
  6522. The @code{source} field of a package that uses this build system
  6523. typically references a gem archive, since this is the format that Ruby
  6524. developers use when releasing their software. The build system unpacks
  6525. the gem archive, potentially patches the source, runs the test suite,
  6526. repackages the gem, and installs it. Additionally, directories and
  6527. tarballs may be referenced to allow building unreleased gems from Git or
  6528. a traditional source release tarball.
  6529. Which Ruby package is used can be specified with the @code{#:ruby}
  6530. parameter. A list of additional flags to be passed to the @command{gem}
  6531. command can be specified with the @code{#:gem-flags} parameter.
  6532. @end defvr
  6533. @defvr {Scheme Variable} waf-build-system
  6534. This variable is exported by @code{(guix build-system waf)}. It
  6535. implements a build procedure around the @code{waf} script. The common
  6536. phases---@code{configure}, @code{build}, and @code{install}---are
  6537. implemented by passing their names as arguments to the @code{waf}
  6538. script.
  6539. The @code{waf} script is executed by the Python interpreter. Which
  6540. Python package is used to run the script can be specified with the
  6541. @code{#:python} parameter.
  6542. @end defvr
  6543. @defvr {Scheme Variable} scons-build-system
  6544. This variable is exported by @code{(guix build-system scons)}. It
  6545. implements the build procedure used by the SCons software construction
  6546. tool. This build system runs @code{scons} to build the package,
  6547. @code{scons test} to run tests, and then @code{scons install} to install
  6548. the package.
  6549. Additional flags to be passed to @code{scons} can be specified with the
  6550. @code{#:scons-flags} parameter. The default build and install targets
  6551. can be overridden with @code{#:build-targets} and
  6552. @code{#:install-targets} respectively. The version of Python used to
  6553. run SCons can be specified by selecting the appropriate SCons package
  6554. with the @code{#:scons} parameter.
  6555. @end defvr
  6556. @defvr {Scheme Variable} haskell-build-system
  6557. This variable is exported by @code{(guix build-system haskell)}. It
  6558. implements the Cabal build procedure used by Haskell packages, which
  6559. involves running @code{runhaskell Setup.hs configure
  6560. --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
  6561. Instead of installing the package by running @code{runhaskell Setup.hs
  6562. install}, to avoid trying to register libraries in the read-only
  6563. compiler store directory, the build system uses @code{runhaskell
  6564. Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
  6565. addition, the build system generates the package documentation by
  6566. running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
  6567. is passed. Optional Haddock parameters can be passed with the help of
  6568. the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
  6569. not found, the build system looks for @code{Setup.lhs} instead.
  6570. Which Haskell compiler is used can be specified with the @code{#:haskell}
  6571. parameter which defaults to @code{ghc}.
  6572. @end defvr
  6573. @defvr {Scheme Variable} dub-build-system
  6574. This variable is exported by @code{(guix build-system dub)}. It
  6575. implements the Dub build procedure used by D packages, which
  6576. involves running @code{dub build} and @code{dub run}.
  6577. Installation is done by copying the files manually.
  6578. Which D compiler is used can be specified with the @code{#:ldc}
  6579. parameter which defaults to @code{ldc}.
  6580. @end defvr
  6581. @anchor{emacs-build-system}
  6582. @defvr {Scheme Variable} emacs-build-system
  6583. This variable is exported by @code{(guix build-system emacs)}. It
  6584. implements an installation procedure similar to the packaging system
  6585. of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
  6586. It first creates the @code{@code{package}-autoloads.el} file, then it
  6587. byte compiles all Emacs Lisp files. Differently from the Emacs
  6588. packaging system, the Info documentation files are moved to the standard
  6589. documentation directory and the @file{dir} file is deleted. The Elisp
  6590. package files are installed directly under @file{share/emacs/site-lisp}.
  6591. @end defvr
  6592. @defvr {Scheme Variable} font-build-system
  6593. This variable is exported by @code{(guix build-system font)}. It
  6594. implements an installation procedure for font packages where upstream
  6595. provides pre-compiled TrueType, OpenType, etc.@: font files that merely
  6596. need to be copied into place. It copies font files to standard
  6597. locations in the output directory.
  6598. @end defvr
  6599. @defvr {Scheme Variable} meson-build-system
  6600. This variable is exported by @code{(guix build-system meson)}. It
  6601. implements the build procedure for packages that use
  6602. @url{https://mesonbuild.com, Meson} as their build system.
  6603. It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
  6604. of inputs, and they can be changed with the parameters @code{#:meson}
  6605. and @code{#:ninja} if needed. The default Meson is
  6606. @code{meson-for-build}, which is special because it doesn't clear the
  6607. @code{RUNPATH} of binaries and libraries when they are installed.
  6608. This build system is an extension of @code{gnu-build-system}, but with the
  6609. following phases changed to some specific for Meson:
  6610. @table @code
  6611. @item configure
  6612. The phase runs @code{meson} with the flags specified in
  6613. @code{#:configure-flags}. The flag @option{--buildtype} is always set to
  6614. @code{debugoptimized} unless something else is specified in
  6615. @code{#:build-type}.
  6616. @item build
  6617. The phase runs @code{ninja} to build the package in parallel by default, but
  6618. this can be changed with @code{#:parallel-build?}.
  6619. @item check
  6620. The phase runs @code{ninja} with the target specified in @code{#:test-target},
  6621. which is @code{"test"} by default.
  6622. @item install
  6623. The phase runs @code{ninja install} and can not be changed.
  6624. @end table
  6625. Apart from that, the build system also adds the following phases:
  6626. @table @code
  6627. @item fix-runpath
  6628. This phase ensures that all binaries can find the libraries they need.
  6629. It searches for required libraries in subdirectories of the package being
  6630. built, and adds those to @code{RUNPATH} where needed. It also removes
  6631. references to libraries left over from the build phase by
  6632. @code{meson-for-build}, such as test dependencies, that aren't actually
  6633. required for the program to run.
  6634. @item glib-or-gtk-wrap
  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. @item glib-or-gtk-compile-schemas
  6638. This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
  6639. is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
  6640. @end table
  6641. @end defvr
  6642. @defvr {Scheme Variable} linux-module-build-system
  6643. @code{linux-module-build-system} allows building Linux kernel modules.
  6644. @cindex build phases
  6645. This build system is an extension of @code{gnu-build-system}, but with the
  6646. following phases changed:
  6647. @table @code
  6648. @item configure
  6649. This phase configures the environment so that the Linux kernel's Makefile
  6650. can be used to build the external kernel module.
  6651. @item build
  6652. This phase uses the Linux kernel's Makefile in order to build the external
  6653. kernel module.
  6654. @item install
  6655. This phase uses the Linux kernel's Makefile in order to install the external
  6656. kernel module.
  6657. @end table
  6658. It is possible and useful to specify the Linux kernel to use for building
  6659. the module (in the @code{arguments} form of a package using the
  6660. @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
  6661. @end defvr
  6662. @defvr {Scheme Variable} node-build-system
  6663. This variable is exported by @code{(guix build-system node)}. It
  6664. implements the build procedure used by @uref{https://nodejs.org,
  6665. Node.js}, which implements an approximation of the @code{npm install}
  6666. command, followed by an @code{npm test} command.
  6667. Which Node.js package is used to interpret the @code{npm} commands can
  6668. be specified with the @code{#:node} parameter which defaults to
  6669. @code{node}.
  6670. @end defvr
  6671. Lastly, for packages that do not need anything as sophisticated, a
  6672. ``trivial'' build system is provided. It is trivial in the sense that
  6673. it provides basically no support: it does not pull any implicit inputs,
  6674. and does not have a notion of build phases.
  6675. @defvr {Scheme Variable} trivial-build-system
  6676. This variable is exported by @code{(guix build-system trivial)}.
  6677. This build system requires a @code{#:builder} argument. This argument
  6678. must be a Scheme expression that builds the package output(s)---as
  6679. with @code{build-expression->derivation} (@pxref{Derivations,
  6680. @code{build-expression->derivation}}).
  6681. @end defvr
  6682. @node Build Phases
  6683. @section Build Phases
  6684. @cindex build phases, for packages
  6685. Almost all package build systems implement a notion @dfn{build phases}:
  6686. a sequence of actions that the build system executes, when you build the
  6687. package, leading to the installed byproducts in the store. A notable
  6688. exception is the ``bare-bones'' @code{trivial-build-system}
  6689. (@pxref{Build Systems}).
  6690. As discussed in the previous section, those build systems provide a
  6691. standard list of phases. For @code{gnu-build-system}, the standard
  6692. phases include an @code{unpack} phase to unpack the source code tarball,
  6693. a @command{configure} phase to run @code{./configure}, a @code{build}
  6694. phase to run @command{make}, and (among others) an @code{install} phase
  6695. to run @command{make install}; @pxref{Build Systems}, for a more
  6696. detailed view of these phases. Likewise, @code{cmake-build-system}
  6697. inherits these phases, but its @code{configure} phase runs
  6698. @command{cmake} instead of @command{./configure}. Other build systems,
  6699. such as @code{python-build-system}, have a wholly different list of
  6700. standard phases. All this code runs on the @dfn{build side}: it is
  6701. evaluated when you actually build the package, in a dedicated build
  6702. process spawned by the build daemon (@pxref{Invoking guix-daemon}).
  6703. Build phases are represented as association lists or ``alists''
  6704. (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
  6705. each key is a symbol for the name of the phase and the associated value
  6706. is a procedure that accepts an arbitrary number of arguments. By
  6707. convention, those procedures receive information about the build in the
  6708. form of @dfn{keyword parameters}, which they can use or ignore.
  6709. For example, here is how @code{(guix build gnu-build-system)} defines
  6710. @code{%standard-phases}, the variable holding its alist of build
  6711. phases@footnote{We present a simplified view of those build phases, but
  6712. do take a look at @code{(guix build gnu-build-system)} to see all the
  6713. details!}:
  6714. @lisp
  6715. ;; The build phases of 'gnu-build-system'.
  6716. (define* (unpack #:key source #:allow-other-keys)
  6717. ;; Extract the source tarball.
  6718. (invoke "tar" "xvf" source))
  6719. (define* (configure #:key outputs #:allow-other-keys)
  6720. ;; Run the 'configure' script. Install to output "out".
  6721. (let ((out (assoc-ref outputs "out")))
  6722. (invoke "./configure"
  6723. (string-append "--prefix=" out))))
  6724. (define* (build #:allow-other-keys)
  6725. ;; Compile.
  6726. (invoke "make"))
  6727. (define* (check #:key (test-target "check") (tests? #true)
  6728. #:allow-other-keys)
  6729. ;; Run the test suite.
  6730. (if tests?
  6731. (invoke "make" test-target)
  6732. (display "test suite not run\n")))
  6733. (define* (install #:allow-other-keys)
  6734. ;; Install files to the prefix 'configure' specified.
  6735. (invoke "make" "install"))
  6736. (define %standard-phases
  6737. ;; The list of standard phases (quite a few are omitted
  6738. ;; for brevity). Each element is a symbol/procedure pair.
  6739. (list (cons 'unpack unpack)
  6740. (cons 'configure configure)
  6741. (cons 'build build)
  6742. (cons 'check check)
  6743. (cons 'install install)))
  6744. @end lisp
  6745. This shows how @code{%standard-phases} is defined as a list of
  6746. symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
  6747. Manual}). The first pair associates the @code{unpack} procedure with
  6748. the @code{unpack} symbol---a name; the second pair defines the
  6749. @code{configure} phase similarly, and so on. When building a package
  6750. that uses @code{gnu-build-system} with its default list of phases, those
  6751. phases are executed sequentially. You can see the name of each phase
  6752. started and completed in the build log of packages that you build.
  6753. Let's now look at the procedures themselves. Each one is defined with
  6754. @code{define*}: @code{#:key} lists keyword parameters the procedure
  6755. accepts, possibly with a default value, and @code{#:allow-other-keys}
  6756. specifies that other keyword parameters are ignored (@pxref{Optional
  6757. Arguments,,, guile, GNU Guile Reference Manual}).
  6758. The @code{unpack} procedure honors the @code{source} parameter, which
  6759. the build system uses to pass the file name of the source tarball (or
  6760. version control checkout), and it ignores other parameters. The
  6761. @code{configure} phase only cares about the @code{outputs} parameter, an
  6762. alist mapping package output names to their store file name
  6763. (@pxref{Packages with Multiple Outputs}). It extracts the file name of
  6764. for @code{out}, the default output, and passes it to
  6765. @command{./configure} as the installation prefix, meaning that
  6766. @command{make install} will eventually copy all the files in that
  6767. directory (@pxref{Configuration, configuration and makefile
  6768. conventions,, standards, GNU Coding Standards}). @code{build} and
  6769. @code{install} ignore all their arguments. @code{check} honors the
  6770. @code{test-target} argument, which specifies the name of the Makefile
  6771. target to run tests; it prints a message and skips tests when
  6772. @code{tests?} is false.
  6773. @cindex build phases, customizing
  6774. The list of phases used for a particular package can be changed with the
  6775. @code{#:phases} parameter of the build system. Changing the set of
  6776. build phases boils down to building a new alist of phases based on the
  6777. @code{%standard-phases} alist described above. This can be done with
  6778. standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
  6779. Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
  6780. more convenient to do so with @code{modify-phases} (@pxref{Build
  6781. Utilities, @code{modify-phases}}).
  6782. Here is an example of a package definition that removes the
  6783. @code{configure} phase of @code{%standard-phases} and inserts a new
  6784. phase before the @code{build} phase, called
  6785. @code{set-prefix-in-makefile}:
  6786. @lisp
  6787. (define-public example
  6788. (package
  6789. (name "example")
  6790. ;; other fields omitted
  6791. (build-system gnu-build-system)
  6792. (arguments
  6793. '(#:phases (modify-phases %standard-phases
  6794. (delete 'configure)
  6795. (add-before 'build 'set-prefix-in-makefile
  6796. (lambda* (#:key outputs #:allow-other-keys)
  6797. ;; Modify the makefile so that its
  6798. ;; 'PREFIX' variable points to "out".
  6799. (let ((out (assoc-ref outputs "out")))
  6800. (substitute* "Makefile"
  6801. (("PREFIX =.*")
  6802. (string-append "PREFIX = "
  6803. out "\n")))
  6804. #true))))))))
  6805. @end lisp
  6806. The new phase that is inserted is written as an anonymous procedure,
  6807. introduced with @code{lambda*}; it honors the @code{outputs} parameter
  6808. we have seen before. @xref{Build Utilities}, for more about the helpers
  6809. used by this phase, and for more examples of @code{modify-phases}.
  6810. @cindex code staging
  6811. @cindex staging, of code
  6812. Keep in mind that build phases are code evaluated at the time the
  6813. package is actually built. This explains why the whole
  6814. @code{modify-phases} expression above is quoted (it comes after the
  6815. @code{'} or apostrophe): it is @dfn{staged} for later execution.
  6816. @xref{G-Expressions}, for an explanation of code staging and the
  6817. @dfn{code strata} involved.
  6818. @node Build Utilities
  6819. @section Build Utilities
  6820. As soon as you start writing non-trivial package definitions
  6821. (@pxref{Defining Packages}) or other build actions
  6822. (@pxref{G-Expressions}), you will likely start looking for helpers for
  6823. ``shell-like'' actions---creating directories, copying and deleting
  6824. files recursively, manipulating build phases, and so on. The
  6825. @code{(guix build utils)} module provides such utility procedures.
  6826. Most build systems load @code{(guix build utils)} (@pxref{Build
  6827. Systems}). Thus, when writing custom build phases for your package
  6828. definitions, you can usually assume those procedures are in scope.
  6829. When writing G-expressions, you can import @code{(guix build utils)} on
  6830. the ``build side'' using @code{with-imported-modules} and then put it in
  6831. scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
  6832. guile, GNU Guile Reference Manual}):
  6833. @lisp
  6834. (with-imported-modules '((guix build utils)) ;import it
  6835. (computed-file "empty-tree"
  6836. #~(begin
  6837. ;; Put it in scope.
  6838. (use-modules (guix build utils))
  6839. ;; Happily use its 'mkdir-p' procedure.
  6840. (mkdir-p (string-append #$output "/a/b/c")))))
  6841. @end lisp
  6842. The remainder of this section is the reference for most of the utility
  6843. procedures provided by @code{(guix build utils)}.
  6844. @c TODO Document what's missing.
  6845. @subsection Dealing with Store File Names
  6846. This section documents procedures that deal with store file names.
  6847. @deffn {Scheme Procedure} %store-directory
  6848. Return the directory name of the store.
  6849. @end deffn
  6850. @deffn {Scheme Procedure} store-file-name? @var{file}
  6851. Return true if @var{file} is in the store.
  6852. @end deffn
  6853. @deffn {Scheme Procedure} strip-store-file-name @var{file}
  6854. Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
  6855. The result is typically a @code{"@var{package}-@var{version}"} string.
  6856. @end deffn
  6857. @deffn {Scheme Procedure} package-name->name+version @var{name}
  6858. Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
  6859. values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
  6860. unavailable, @var{name} and @code{#f} are returned. The first hyphen
  6861. followed by a digit is considered to introduce the version part.
  6862. @end deffn
  6863. @subsection File Types
  6864. The procedures below deal with files and file types.
  6865. @deffn {Scheme Procedure} directory-exists? @var{dir}
  6866. Return @code{#t} if @var{dir} exists and is a directory.
  6867. @end deffn
  6868. @deffn {Scheme Procedure} executable-file? @var{file}
  6869. Return @code{#t} if @var{file} exists and is executable.
  6870. @end deffn
  6871. @deffn {Scheme Procedure} symbolic-link? @var{file}
  6872. Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
  6873. @end deffn
  6874. @deffn {Scheme Procedure} elf-file? @var{file}
  6875. @deffnx {Scheme Procedure} ar-file? @var{file}
  6876. @deffnx {Scheme Procedure} gzip-file? @var{file}
  6877. Return @code{#t} if @var{file} is, respectively, an ELF file, an
  6878. @code{ar} archive (such as a @file{.a} static library), or a gzip file.
  6879. @end deffn
  6880. @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
  6881. If @var{file} is a gzip file, reset its embedded timestamp (as with
  6882. @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
  6883. When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
  6884. @end deffn
  6885. @subsection File Manipulation
  6886. The following procedures and macros help create, modify, and delete
  6887. files. They provide functionality comparable to common shell utilities
  6888. such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
  6889. @command{sed}. They complement Guile's extensive, but low-level, file
  6890. system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
  6891. @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
  6892. Run @var{body} with @var{directory} as the process's current directory.
  6893. Essentially, this macro changes the current directory to @var{directory}
  6894. before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
  6895. guile, GNU Guile Reference Manual}). It changes back to the initial
  6896. directory when the dynamic extent of @var{body} is left, be it @i{via}
  6897. normal procedure return or @i{via} a non-local exit such as an
  6898. exception.
  6899. @end deffn
  6900. @deffn {Scheme Procedure} mkdir-p @var{dir}
  6901. Create directory @var{dir} and all its ancestors.
  6902. @end deffn
  6903. @deffn {Scheme Procedure} install-file @var{file} @var{directory}
  6904. Create @var{directory} if it does not exist and copy @var{file} in there
  6905. under the same name.
  6906. @end deffn
  6907. @deffn {Scheme Procedure} make-file-writable @var{file}
  6908. Make @var{file} writable for its owner.
  6909. @end deffn
  6910. @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
  6911. [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
  6912. Copy @var{source} directory to @var{destination}. Follow symlinks if
  6913. @var{follow-symlinks?} is true; otherwise, just preserve them. When
  6914. @var{keep-mtime?} is true, keep the modification time of the files in
  6915. @var{source} on those of @var{destination}. Write verbose output to the
  6916. @var{log} port.
  6917. @end deffn
  6918. @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
  6919. [#:follow-mounts? #f]
  6920. Delete @var{dir} recursively, like @command{rm -rf}, without following
  6921. symlinks. Don't follow mount points either, unless @var{follow-mounts?}
  6922. is true. Report but ignore errors.
  6923. @end deffn
  6924. @deffn {Scheme Syntax} substitute* @var{file} @
  6925. ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
  6926. Substitute @var{regexp} in @var{file} by the string returned by
  6927. @var{body}. @var{body} is evaluated with each @var{match-var} bound to
  6928. the corresponding positional regexp sub-expression. For example:
  6929. @lisp
  6930. (substitute* file
  6931. (("hello")
  6932. "good morning\n")
  6933. (("foo([a-z]+)bar(.*)$" all letters end)
  6934. (string-append "baz" letter end)))
  6935. @end lisp
  6936. Here, anytime a line of @var{file} contains @code{hello}, it is replaced
  6937. by @code{good morning}. Anytime a line of @var{file} matches the second
  6938. regexp, @code{all} is bound to the complete match, @code{letters} is bound
  6939. to the first sub-expression, and @code{end} is bound to the last one.
  6940. When one of the @var{match-var} is @code{_}, no variable is bound to the
  6941. corresponding match substring.
  6942. Alternatively, @var{file} may be a list of file names, in which case
  6943. they are all subject to the substitutions.
  6944. Be careful about using @code{$} to match the end of a line; by itself it
  6945. won't match the terminating newline of a line.
  6946. @end deffn
  6947. @subsection File Search
  6948. @cindex file, searching
  6949. This section documents procedures to search and filter files.
  6950. @deffn {Scheme Procedure} file-name-predicate @var{regexp}
  6951. Return a predicate that returns true when passed a file name whose base
  6952. name matches @var{regexp}.
  6953. @end deffn
  6954. @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
  6955. [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
  6956. Return the lexicographically sorted list of files under @var{dir} for
  6957. which @var{pred} returns true. @var{pred} is passed two arguments: the
  6958. absolute file name, and its stat buffer; the default predicate always
  6959. returns true. @var{pred} can also be a regular expression, in which
  6960. case it is equivalent to @code{(file-name-predicate @var{pred})}.
  6961. @var{stat} is used to obtain file information; using @code{lstat} means
  6962. that symlinks are not followed. If @var{directories?} is true, then
  6963. directories will also be included. If @var{fail-on-error?} is true,
  6964. raise an exception upon error.
  6965. @end deffn
  6966. Here are a few examples where we assume that the current directory is
  6967. the root of the Guix source tree:
  6968. @lisp
  6969. ;; List all the regular files in the current directory.
  6970. (find-files ".")
  6971. @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
  6972. ;; List all the .scm files under gnu/services.
  6973. (find-files "gnu/services" "\\.scm$")
  6974. @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
  6975. ;; List ar files in the current directory.
  6976. (find-files "." (lambda (file stat) (ar-file? file)))
  6977. @result{} ("./libformat.a" "./libstore.a" @dots{})
  6978. @end lisp
  6979. @deffn {Scheme Procedure} which @var{program}
  6980. Return the complete file name for @var{program} as found in
  6981. @code{$PATH}, or @code{#f} if @var{program} could not be found.
  6982. @end deffn
  6983. @subsection Build Phases
  6984. @cindex build phases
  6985. The @code{(guix build utils)} also contains tools to manipulate build
  6986. phases as used by build systems (@pxref{Build Systems}). Build phases
  6987. are represented as association lists or ``alists'' (@pxref{Association
  6988. Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
  6989. naming the phase and the associated value is a procedure (@pxref{Build
  6990. Phases}).
  6991. Guile core and the @code{(srfi srfi-1)} module both provide tools to
  6992. manipulate alists. The @code{(guix build utils)} module complements
  6993. those with tools written with build phases in mind.
  6994. @cindex build phases, modifying
  6995. @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
  6996. Modify @var{phases} sequentially as per each @var{clause}, which may
  6997. have one of the following forms:
  6998. @lisp
  6999. (delete @var{old-phase-name})
  7000. (replace @var{old-phase-name} @var{new-phase})
  7001. (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
  7002. (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
  7003. @end lisp
  7004. Where every @var{phase-name} above is an expression evaluating to a
  7005. symbol, and @var{new-phase} an expression evaluating to a procedure.
  7006. @end deffn
  7007. The example below is taken from the definition of the @code{grep}
  7008. package. It adds a phase to run after the @code{install} phase, called
  7009. @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
  7010. is for anonymous procedures) that takes a @code{#:outputs} keyword
  7011. argument and ignores extra keyword arguments (@pxref{Optional
  7012. Arguments,,, guile, GNU Guile Reference Manual}, for more on
  7013. @code{lambda*} and optional and keyword arguments.) The phase uses
  7014. @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
  7015. scripts so that they refer to @code{grep} by its absolute file name:
  7016. @lisp
  7017. (modify-phases %standard-phases
  7018. (add-after 'install 'fix-egrep-and-fgrep
  7019. ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
  7020. ;; absolute file name instead of searching for it in $PATH.
  7021. (lambda* (#:key outputs #:allow-other-keys)
  7022. (let* ((out (assoc-ref outputs "out"))
  7023. (bin (string-append out "/bin")))
  7024. (substitute* (list (string-append bin "/egrep")
  7025. (string-append bin "/fgrep"))
  7026. (("^exec grep")
  7027. (string-append "exec " bin "/grep")))
  7028. #t))))
  7029. @end lisp
  7030. In the example below, phases are modified in two ways: the standard
  7031. @code{configure} phase is deleted, presumably because the package does
  7032. not have a @file{configure} script or anything similar, and the default
  7033. @code{install} phase is replaced by one that manually copies the
  7034. executable files to be installed:
  7035. @lisp
  7036. (modify-phases %standard-phases
  7037. (delete 'configure) ;no 'configure' script
  7038. (replace 'install
  7039. (lambda* (#:key outputs #:allow-other-keys)
  7040. ;; The package's Makefile doesn't provide an "install"
  7041. ;; rule so do it by ourselves.
  7042. (let ((bin (string-append (assoc-ref outputs "out")
  7043. "/bin")))
  7044. (install-file "footswitch" bin)
  7045. (install-file "scythe" bin)
  7046. #t))))
  7047. @end lisp
  7048. @c TODO: Add more examples.
  7049. @node The Store
  7050. @section The Store
  7051. @cindex store
  7052. @cindex store items
  7053. @cindex store paths
  7054. Conceptually, the @dfn{store} is the place where derivations that have
  7055. been built successfully are stored---by default, @file{/gnu/store}.
  7056. Sub-directories in the store are referred to as @dfn{store items} or
  7057. sometimes @dfn{store paths}. The store has an associated database that
  7058. contains information such as the store paths referred to by each store
  7059. path, and the list of @emph{valid} store items---results of successful
  7060. builds. This database resides in @file{@var{localstatedir}/guix/db},
  7061. where @var{localstatedir} is the state directory specified @i{via}
  7062. @option{--localstatedir} at configure time, usually @file{/var}.
  7063. The store is @emph{always} accessed by the daemon on behalf of its clients
  7064. (@pxref{Invoking guix-daemon}). To manipulate the store, clients
  7065. connect to the daemon over a Unix-domain socket, send requests to it,
  7066. and read the result---these are remote procedure calls, or RPCs.
  7067. @quotation Note
  7068. Users must @emph{never} modify files under @file{/gnu/store} directly.
  7069. This would lead to inconsistencies and break the immutability
  7070. assumptions of Guix's functional model (@pxref{Introduction}).
  7071. @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
  7072. how to check the integrity of the store and attempt recovery from
  7073. accidental modifications.
  7074. @end quotation
  7075. The @code{(guix store)} module provides procedures to connect to the
  7076. daemon, and to perform RPCs. These are described below. By default,
  7077. @code{open-connection}, and thus all the @command{guix} commands,
  7078. connect to the local daemon or to the URI specified by the
  7079. @env{GUIX_DAEMON_SOCKET} environment variable.
  7080. @defvr {Environment Variable} GUIX_DAEMON_SOCKET
  7081. When set, the value of this variable should be a file name or a URI
  7082. designating the daemon endpoint. When it is a file name, it denotes a
  7083. Unix-domain socket to connect to. In addition to file names, the
  7084. supported URI schemes are:
  7085. @table @code
  7086. @item file
  7087. @itemx unix
  7088. These are for Unix-domain sockets.
  7089. @code{file:///var/guix/daemon-socket/socket} is equivalent to
  7090. @file{/var/guix/daemon-socket/socket}.
  7091. @item guix
  7092. @cindex daemon, remote access
  7093. @cindex remote access to the daemon
  7094. @cindex daemon, cluster setup
  7095. @cindex clusters, daemon setup
  7096. These URIs denote connections over TCP/IP, without encryption nor
  7097. authentication of the remote host. The URI must specify the host name
  7098. and optionally a port number (by default port 44146 is used):
  7099. @example
  7100. guix://master.guix.example.org:1234
  7101. @end example
  7102. This setup is suitable on local networks, such as clusters, where only
  7103. trusted nodes may connect to the build daemon at
  7104. @code{master.guix.example.org}.
  7105. The @option{--listen} option of @command{guix-daemon} can be used to
  7106. instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
  7107. @option{--listen}}).
  7108. @item ssh
  7109. @cindex SSH access to build daemons
  7110. These URIs allow you to connect to a remote daemon over SSH@. This
  7111. feature requires Guile-SSH (@pxref{Requirements}) and a working
  7112. @command{guile} binary in @env{PATH} on the destination machine. It
  7113. supports public key and GSSAPI authentication. A typical URL might look
  7114. like this:
  7115. @example
  7116. ssh://charlie@@guix.example.org:22
  7117. @end example
  7118. As for @command{guix copy}, the usual OpenSSH client configuration files
  7119. are honored (@pxref{Invoking guix copy}).
  7120. @end table
  7121. Additional URI schemes may be supported in the future.
  7122. @c XXX: Remove this note when the protocol incurs fewer round trips
  7123. @c and when (guix derivations) no longer relies on file system access.
  7124. @quotation Note
  7125. The ability to connect to remote build daemons is considered
  7126. experimental as of @value{VERSION}. Please get in touch with us to
  7127. share any problems or suggestions you may have (@pxref{Contributing}).
  7128. @end quotation
  7129. @end defvr
  7130. @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
  7131. Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
  7132. @var{reserve-space?} is true, instruct it to reserve a little bit of
  7133. extra space on the file system so that the garbage collector can still
  7134. operate should the disk become full. Return a server object.
  7135. @var{file} defaults to @code{%default-socket-path}, which is the normal
  7136. location given the options that were passed to @command{configure}.
  7137. @end deffn
  7138. @deffn {Scheme Procedure} close-connection @var{server}
  7139. Close the connection to @var{server}.
  7140. @end deffn
  7141. @defvr {Scheme Variable} current-build-output-port
  7142. This variable is bound to a SRFI-39 parameter, which refers to the port
  7143. where build and error logs sent by the daemon should be written.
  7144. @end defvr
  7145. Procedures that make RPCs all take a server object as their first
  7146. argument.
  7147. @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
  7148. @cindex invalid store items
  7149. Return @code{#t} when @var{path} designates a valid store item and
  7150. @code{#f} otherwise (an invalid item may exist on disk but still be
  7151. invalid, for instance because it is the result of an aborted or failed
  7152. build).
  7153. A @code{&store-protocol-error} condition is raised if @var{path} is not
  7154. prefixed by the store directory (@file{/gnu/store}).
  7155. @end deffn
  7156. @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
  7157. Add @var{text} under file @var{name} in the store, and return its store
  7158. path. @var{references} is the list of store paths referred to by the
  7159. resulting store path.
  7160. @end deffn
  7161. @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
  7162. [@var{mode}]
  7163. Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
  7164. file names, or derivation/output pairs, using the specified
  7165. @var{mode}---@code{(build-mode normal)} by default.
  7166. @end deffn
  7167. Note that the @code{(guix monads)} module provides a monad as well as
  7168. monadic versions of the above procedures, with the goal of making it
  7169. more convenient to work with code that accesses the store (@pxref{The
  7170. Store Monad}).
  7171. @c FIXME
  7172. @i{This section is currently incomplete.}
  7173. @node Derivations
  7174. @section Derivations
  7175. @cindex derivations
  7176. Low-level build actions and the environment in which they are performed
  7177. are represented by @dfn{derivations}. A derivation contains the
  7178. following pieces of information:
  7179. @itemize
  7180. @item
  7181. The outputs of the derivation---derivations produce at least one file or
  7182. directory in the store, but may produce more.
  7183. @item
  7184. @cindex build-time dependencies
  7185. @cindex dependencies, build-time
  7186. The inputs of the derivations---i.e., its build-time dependencies---which may
  7187. be other derivations or plain files in the store (patches, build scripts,
  7188. etc.).
  7189. @item
  7190. The system type targeted by the derivation---e.g., @code{x86_64-linux}.
  7191. @item
  7192. The file name of a build script in the store, along with the arguments
  7193. to be passed.
  7194. @item
  7195. A list of environment variables to be defined.
  7196. @end itemize
  7197. @cindex derivation path
  7198. Derivations allow clients of the daemon to communicate build actions to
  7199. the store. They exist in two forms: as an in-memory representation,
  7200. both on the client- and daemon-side, and as files in the store whose
  7201. name end in @file{.drv}---these files are referred to as @dfn{derivation
  7202. paths}. Derivations paths can be passed to the @code{build-derivations}
  7203. procedure to perform the build actions they prescribe (@pxref{The
  7204. Store}).
  7205. @cindex fixed-output derivations
  7206. Operations such as file downloads and version-control checkouts for
  7207. which the expected content hash is known in advance are modeled as
  7208. @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
  7209. of a fixed-output derivation are independent of its inputs---e.g., a
  7210. source code download produces the same result regardless of the download
  7211. method and tools being used.
  7212. @cindex references
  7213. @cindex run-time dependencies
  7214. @cindex dependencies, run-time
  7215. The outputs of derivations---i.e., the build results---have a set of
  7216. @dfn{references}, as reported by the @code{references} RPC or the
  7217. @command{guix gc --references} command (@pxref{Invoking guix gc}). References
  7218. are the set of run-time dependencies of the build results. References are a
  7219. subset of the inputs of the derivation; this subset is automatically computed
  7220. by the build daemon by scanning all the files in the outputs.
  7221. The @code{(guix derivations)} module provides a representation of
  7222. derivations as Scheme objects, along with procedures to create and
  7223. otherwise manipulate derivations. The lowest-level primitive to create
  7224. a derivation is the @code{derivation} procedure:
  7225. @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
  7226. @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
  7227. [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
  7228. [#:system (%current-system)] [#:references-graphs #f] @
  7229. [#:allowed-references #f] [#:disallowed-references #f] @
  7230. [#:leaked-env-vars #f] [#:local-build? #f] @
  7231. [#:substitutable? #t] [#:properties '()]
  7232. Build a derivation with the given arguments, and return the resulting
  7233. @code{<derivation>} object.
  7234. When @var{hash} and @var{hash-algo} are given, a
  7235. @dfn{fixed-output derivation} is created---i.e., one whose result is
  7236. known in advance, such as a file download. If, in addition,
  7237. @var{recursive?} is true, then that fixed output may be an executable
  7238. file or a directory and @var{hash} must be the hash of an archive
  7239. containing this output.
  7240. When @var{references-graphs} is true, it must be a list of file
  7241. name/store path pairs. In that case, the reference graph of each store
  7242. path is exported in the build environment in the corresponding file, in
  7243. a simple text format.
  7244. When @var{allowed-references} is true, it must be a list of store items
  7245. or outputs that the derivation's output may refer to. Likewise,
  7246. @var{disallowed-references}, if true, must be a list of things the
  7247. outputs may @emph{not} refer to.
  7248. When @var{leaked-env-vars} is true, it must be a list of strings
  7249. denoting environment variables that are allowed to ``leak'' from the
  7250. daemon's environment to the build environment. This is only applicable
  7251. to fixed-output derivations---i.e., when @var{hash} is true. The main
  7252. use is to allow variables such as @code{http_proxy} to be passed to
  7253. derivations that download files.
  7254. When @var{local-build?} is true, declare that the derivation is not a
  7255. good candidate for offloading and should rather be built locally
  7256. (@pxref{Daemon Offload Setup}). This is the case for small derivations
  7257. where the costs of data transfers would outweigh the benefits.
  7258. When @var{substitutable?} is false, declare that substitutes of the
  7259. derivation's output should not be used (@pxref{Substitutes}). This is
  7260. useful, for instance, when building packages that capture details of the
  7261. host CPU instruction set.
  7262. @var{properties} must be an association list describing ``properties'' of the
  7263. derivation. It is kept as-is, uninterpreted, in the derivation.
  7264. @end deffn
  7265. @noindent
  7266. Here's an example with a shell script as its builder, assuming
  7267. @var{store} is an open connection to the daemon, and @var{bash} points
  7268. to a Bash executable in the store:
  7269. @lisp
  7270. (use-modules (guix utils)
  7271. (guix store)
  7272. (guix derivations))
  7273. (let ((builder ; add the Bash script to the store
  7274. (add-text-to-store store "my-builder.sh"
  7275. "echo hello world > $out\n" '())))
  7276. (derivation store "foo"
  7277. bash `("-e" ,builder)
  7278. #:inputs `((,bash) (,builder))
  7279. #:env-vars '(("HOME" . "/homeless"))))
  7280. @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
  7281. @end lisp
  7282. As can be guessed, this primitive is cumbersome to use directly. A
  7283. better approach is to write build scripts in Scheme, of course! The
  7284. best course of action for that is to write the build code as a
  7285. ``G-expression'', and to pass it to @code{gexp->derivation}. For more
  7286. information, @pxref{G-Expressions}.
  7287. Once upon a time, @code{gexp->derivation} did not exist and constructing
  7288. derivations with build code written in Scheme was achieved with
  7289. @code{build-expression->derivation}, documented below. This procedure
  7290. is now deprecated in favor of the much nicer @code{gexp->derivation}.
  7291. @deffn {Scheme Procedure} build-expression->derivation @var{store} @
  7292. @var{name} @var{exp} @
  7293. [#:system (%current-system)] [#:inputs '()] @
  7294. [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
  7295. [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
  7296. [#:references-graphs #f] [#:allowed-references #f] @
  7297. [#:disallowed-references #f] @
  7298. [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
  7299. Return a derivation that executes Scheme expression @var{exp} as a
  7300. builder for derivation @var{name}. @var{inputs} must be a list of
  7301. @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
  7302. @code{"out"} is assumed. @var{modules} is a list of names of Guile
  7303. modules from the current search path to be copied in the store,
  7304. compiled, and made available in the load path during the execution of
  7305. @var{exp}---e.g., @code{((guix build utils) (guix build
  7306. gnu-build-system))}.
  7307. @var{exp} is evaluated in an environment where @code{%outputs} is bound
  7308. to a list of output/path pairs, and where @code{%build-inputs} is bound
  7309. to a list of string/output-path pairs made from @var{inputs}.
  7310. Optionally, @var{env-vars} is a list of string pairs specifying the name
  7311. and value of environment variables visible to the builder. The builder
  7312. terminates by passing the result of @var{exp} to @code{exit}; thus, when
  7313. @var{exp} returns @code{#f}, the build is considered to have failed.
  7314. @var{exp} is built using @var{guile-for-build} (a derivation). When
  7315. @var{guile-for-build} is omitted or is @code{#f}, the value of the
  7316. @code{%guile-for-build} fluid is used instead.
  7317. See the @code{derivation} procedure for the meaning of
  7318. @var{references-graphs}, @var{allowed-references},
  7319. @var{disallowed-references}, @var{local-build?}, and
  7320. @var{substitutable?}.
  7321. @end deffn
  7322. @noindent
  7323. Here's an example of a single-output derivation that creates a directory
  7324. containing one file:
  7325. @lisp
  7326. (let ((builder '(let ((out (assoc-ref %outputs "out")))
  7327. (mkdir out) ; create /gnu/store/@dots{}-goo
  7328. (call-with-output-file (string-append out "/test")
  7329. (lambda (p)
  7330. (display '(hello guix) p))))))
  7331. (build-expression->derivation store "goo" builder))
  7332. @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
  7333. @end lisp
  7334. @node The Store Monad
  7335. @section The Store Monad
  7336. @cindex monad
  7337. The procedures that operate on the store described in the previous
  7338. sections all take an open connection to the build daemon as their first
  7339. argument. Although the underlying model is functional, they either have
  7340. side effects or depend on the current state of the store.
  7341. The former is inconvenient: the connection to the build daemon has to be
  7342. carried around in all those functions, making it impossible to compose
  7343. functions that do not take that parameter with functions that do. The
  7344. latter can be problematic: since store operations have side effects
  7345. and/or depend on external state, they have to be properly sequenced.
  7346. @cindex monadic values
  7347. @cindex monadic functions
  7348. This is where the @code{(guix monads)} module comes in. This module
  7349. provides a framework for working with @dfn{monads}, and a particularly
  7350. useful monad for our uses, the @dfn{store monad}. Monads are a
  7351. construct that allows two things: associating ``context'' with values
  7352. (in our case, the context is the store), and building sequences of
  7353. computations (here computations include accesses to the store). Values
  7354. in a monad---values that carry this additional context---are called
  7355. @dfn{monadic values}; procedures that return such values are called
  7356. @dfn{monadic procedures}.
  7357. Consider this ``normal'' procedure:
  7358. @lisp
  7359. (define (sh-symlink store)
  7360. ;; Return a derivation that symlinks the 'bash' executable.
  7361. (let* ((drv (package-derivation store bash))
  7362. (out (derivation->output-path drv))
  7363. (sh (string-append out "/bin/bash")))
  7364. (build-expression->derivation store "sh"
  7365. `(symlink ,sh %output))))
  7366. @end lisp
  7367. Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
  7368. as a monadic function:
  7369. @lisp
  7370. (define (sh-symlink)
  7371. ;; Same, but return a monadic value.
  7372. (mlet %store-monad ((drv (package->derivation bash)))
  7373. (gexp->derivation "sh"
  7374. #~(symlink (string-append #$drv "/bin/bash")
  7375. #$output))))
  7376. @end lisp
  7377. There are several things to note in the second version: the @code{store}
  7378. parameter is now implicit and is ``threaded'' in the calls to the
  7379. @code{package->derivation} and @code{gexp->derivation} monadic
  7380. procedures, and the monadic value returned by @code{package->derivation}
  7381. is @dfn{bound} using @code{mlet} instead of plain @code{let}.
  7382. As it turns out, the call to @code{package->derivation} can even be
  7383. omitted since it will take place implicitly, as we will see later
  7384. (@pxref{G-Expressions}):
  7385. @lisp
  7386. (define (sh-symlink)
  7387. (gexp->derivation "sh"
  7388. #~(symlink (string-append #$bash "/bin/bash")
  7389. #$output)))
  7390. @end lisp
  7391. @c See
  7392. @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
  7393. @c for the funny quote.
  7394. Calling the monadic @code{sh-symlink} has no effect. As someone once
  7395. said, ``you exit a monad like you exit a building on fire: by running''.
  7396. So, to exit the monad and get the desired effect, one must use
  7397. @code{run-with-store}:
  7398. @lisp
  7399. (run-with-store (open-connection) (sh-symlink))
  7400. @result{} /gnu/store/...-sh-symlink
  7401. @end lisp
  7402. Note that the @code{(guix monad-repl)} module extends the Guile REPL with
  7403. new ``meta-commands'' to make it easier to deal with monadic procedures:
  7404. @code{run-in-store}, and @code{enter-store-monad}. The former is used
  7405. to ``run'' a single monadic value through the store:
  7406. @example
  7407. scheme@@(guile-user)> ,run-in-store (package->derivation hello)
  7408. $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
  7409. @end example
  7410. The latter enters a recursive REPL, where all the return values are
  7411. automatically run through the store:
  7412. @example
  7413. scheme@@(guile-user)> ,enter-store-monad
  7414. store-monad@@(guile-user) [1]> (package->derivation hello)
  7415. $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
  7416. store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
  7417. $3 = "/gnu/store/@dots{}-foo"
  7418. store-monad@@(guile-user) [1]> ,q
  7419. scheme@@(guile-user)>
  7420. @end example
  7421. @noindent
  7422. Note that non-monadic values cannot be returned in the
  7423. @code{store-monad} REPL.
  7424. The main syntactic forms to deal with monads in general are provided by
  7425. the @code{(guix monads)} module and are described below.
  7426. @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
  7427. Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
  7428. in @var{monad}.
  7429. @end deffn
  7430. @deffn {Scheme Syntax} return @var{val}
  7431. Return a monadic value that encapsulates @var{val}.
  7432. @end deffn
  7433. @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
  7434. @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
  7435. procedures @var{mproc}@dots{}@footnote{This operation is commonly
  7436. referred to as ``bind'', but that name denotes an unrelated procedure in
  7437. Guile. Thus we use this somewhat cryptic symbol inherited from the
  7438. Haskell language.}. There can be one @var{mproc} or several of them, as
  7439. in this example:
  7440. @lisp
  7441. (run-with-state
  7442. (with-monad %state-monad
  7443. (>>= (return 1)
  7444. (lambda (x) (return (+ 1 x)))
  7445. (lambda (x) (return (* 2 x)))))
  7446. 'some-state)
  7447. @result{} 4
  7448. @result{} some-state
  7449. @end lisp
  7450. @end deffn
  7451. @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
  7452. @var{body} ...
  7453. @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
  7454. @var{body} ...
  7455. Bind the variables @var{var} to the monadic values @var{mval} in
  7456. @var{body}, which is a sequence of expressions. As with the bind
  7457. operator, this can be thought of as ``unpacking'' the raw, non-monadic
  7458. value ``contained'' in @var{mval} and making @var{var} refer to that
  7459. raw, non-monadic value within the scope of the @var{body}. The form
  7460. (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
  7461. @var{val}, as per @code{let}. The binding operations occur in sequence
  7462. from left to right. The last expression of @var{body} must be a monadic
  7463. expression, and its result will become the result of the @code{mlet} or
  7464. @code{mlet*} when run in the @var{monad}.
  7465. @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
  7466. (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
  7467. @end deffn
  7468. @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
  7469. Bind @var{mexp} and the following monadic expressions in sequence,
  7470. returning the result of the last expression. Every expression in the
  7471. sequence must be a monadic expression.
  7472. This is akin to @code{mlet}, except that the return values of the
  7473. monadic expressions are ignored. In that sense, it is analogous to
  7474. @code{begin}, but applied to monadic expressions.
  7475. @end deffn
  7476. @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
  7477. When @var{condition} is true, evaluate the sequence of monadic
  7478. expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
  7479. @var{condition} is false, return @code{*unspecified*} in the current
  7480. monad. Every expression in the sequence must be a monadic expression.
  7481. @end deffn
  7482. @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
  7483. When @var{condition} is false, evaluate the sequence of monadic
  7484. expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
  7485. @var{condition} is true, return @code{*unspecified*} in the current
  7486. monad. Every expression in the sequence must be a monadic expression.
  7487. @end deffn
  7488. @cindex state monad
  7489. The @code{(guix monads)} module provides the @dfn{state monad}, which
  7490. allows an additional value---the state---to be @emph{threaded} through
  7491. monadic procedure calls.
  7492. @defvr {Scheme Variable} %state-monad
  7493. The state monad. Procedures in the state monad can access and change
  7494. the state that is threaded.
  7495. Consider the example below. The @code{square} procedure returns a value
  7496. in the state monad. It returns the square of its argument, but also
  7497. increments the current state value:
  7498. @lisp
  7499. (define (square x)
  7500. (mlet %state-monad ((count (current-state)))
  7501. (mbegin %state-monad
  7502. (set-current-state (+ 1 count))
  7503. (return (* x x)))))
  7504. (run-with-state (sequence %state-monad (map square (iota 3))) 0)
  7505. @result{} (0 1 4)
  7506. @result{} 3
  7507. @end lisp
  7508. When ``run'' through @code{%state-monad}, we obtain that additional state
  7509. value, which is the number of @code{square} calls.
  7510. @end defvr
  7511. @deffn {Monadic Procedure} current-state
  7512. Return the current state as a monadic value.
  7513. @end deffn
  7514. @deffn {Monadic Procedure} set-current-state @var{value}
  7515. Set the current state to @var{value} and return the previous state as a
  7516. monadic value.
  7517. @end deffn
  7518. @deffn {Monadic Procedure} state-push @var{value}
  7519. Push @var{value} to the current state, which is assumed to be a list,
  7520. and return the previous state as a monadic value.
  7521. @end deffn
  7522. @deffn {Monadic Procedure} state-pop
  7523. Pop a value from the current state and return it as a monadic value.
  7524. The state is assumed to be a list.
  7525. @end deffn
  7526. @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
  7527. Run monadic value @var{mval} starting with @var{state} as the initial
  7528. state. Return two values: the resulting value, and the resulting state.
  7529. @end deffn
  7530. The main interface to the store monad, provided by the @code{(guix
  7531. store)} module, is as follows.
  7532. @defvr {Scheme Variable} %store-monad
  7533. The store monad---an alias for @code{%state-monad}.
  7534. Values in the store monad encapsulate accesses to the store. When its
  7535. effect is needed, a value of the store monad must be ``evaluated'' by
  7536. passing it to the @code{run-with-store} procedure (see below).
  7537. @end defvr
  7538. @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
  7539. Run @var{mval}, a monadic value in the store monad, in @var{store}, an
  7540. open store connection.
  7541. @end deffn
  7542. @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
  7543. Return as a monadic value the absolute file name in the store of the file
  7544. containing @var{text}, a string. @var{references} is a list of store items that the
  7545. resulting text file refers to; it defaults to the empty list.
  7546. @end deffn
  7547. @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
  7548. Return as a monadic value the absolute file name in the store of the file
  7549. containing @var{data}, a bytevector. @var{references} is a list of store
  7550. items that the resulting binary file refers to; it defaults to the empty list.
  7551. @end deffn
  7552. @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
  7553. [#:recursive? #t] [#:select? (const #t)]
  7554. Return the name of @var{file} once interned in the store. Use
  7555. @var{name} as its store name, or the basename of @var{file} if
  7556. @var{name} is omitted.
  7557. When @var{recursive?} is true, the contents of @var{file} are added
  7558. recursively; if @var{file} designates a flat file and @var{recursive?}
  7559. is true, its contents are added, and its permission bits are kept.
  7560. When @var{recursive?} is true, call @code{(@var{select?} @var{file}
  7561. @var{stat})} for each directory entry, where @var{file} is the entry's
  7562. absolute file name and @var{stat} is the result of @code{lstat}; exclude
  7563. entries for which @var{select?} does not return true.
  7564. The example below adds a file to the store, under two different names:
  7565. @lisp
  7566. (run-with-store (open-connection)
  7567. (mlet %store-monad ((a (interned-file "README"))
  7568. (b (interned-file "README" "LEGU-MIN")))
  7569. (return (list a b))))
  7570. @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
  7571. @end lisp
  7572. @end deffn
  7573. The @code{(guix packages)} module exports the following package-related
  7574. monadic procedures:
  7575. @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
  7576. [#:system (%current-system)] [#:target #f] @
  7577. [#:output "out"]
  7578. Return as a monadic
  7579. value in the absolute file name of @var{file} within the @var{output}
  7580. directory of @var{package}. When @var{file} is omitted, return the name
  7581. of the @var{output} directory of @var{package}. When @var{target} is
  7582. true, use it as a cross-compilation target triplet.
  7583. Note that this procedure does @emph{not} build @var{package}. Thus, the
  7584. result might or might not designate an existing file. We recommend not
  7585. using this procedure unless you know what you are doing.
  7586. @end deffn
  7587. @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
  7588. @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
  7589. @var{target} [@var{system}]
  7590. Monadic version of @code{package-derivation} and
  7591. @code{package-cross-derivation} (@pxref{Defining Packages}).
  7592. @end deffn
  7593. @node G-Expressions
  7594. @section G-Expressions
  7595. @cindex G-expression
  7596. @cindex build code quoting
  7597. So we have ``derivations'', which represent a sequence of build actions
  7598. to be performed to produce an item in the store (@pxref{Derivations}).
  7599. These build actions are performed when asking the daemon to actually
  7600. build the derivations; they are run by the daemon in a container
  7601. (@pxref{Invoking guix-daemon}).
  7602. @cindex code staging
  7603. @cindex staging, of code
  7604. @cindex strata of code
  7605. It should come as no surprise that we like to write these build actions
  7606. in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
  7607. code@footnote{The term @dfn{stratum} in this context was coined by
  7608. Manuel Serrano et al.@: in the context of their work on Hop. Oleg
  7609. Kiselyov, who has written insightful
  7610. @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
  7611. on this topic}, refers to this kind of code generation as
  7612. @dfn{staging}.}: the ``host code''---code that defines packages, talks
  7613. to the daemon, etc.---and the ``build code''---code that actually
  7614. performs build actions, such as making directories, invoking
  7615. @command{make}, and so on (@pxref{Build Phases}).
  7616. To describe a derivation and its build actions, one typically needs to
  7617. embed build code inside host code. It boils down to manipulating build
  7618. code as data, and the homoiconicity of Scheme---code has a direct
  7619. representation as data---comes in handy for that. But we need more than
  7620. the normal @code{quasiquote} mechanism in Scheme to construct build
  7621. expressions.
  7622. The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
  7623. S-expressions adapted to build expressions. G-expressions, or
  7624. @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
  7625. @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
  7626. @code{#$}, and @code{#$@@}), which are comparable to
  7627. @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
  7628. respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
  7629. GNU Guile Reference Manual}). However, there are major differences:
  7630. @itemize
  7631. @item
  7632. Gexps are meant to be written to a file and run or manipulated by other
  7633. processes.
  7634. @item
  7635. When a high-level object such as a package or derivation is unquoted
  7636. inside a gexp, the result is as if its output file name had been
  7637. introduced.
  7638. @item
  7639. Gexps carry information about the packages or derivations they refer to,
  7640. and these dependencies are automatically added as inputs to the build
  7641. processes that use them.
  7642. @end itemize
  7643. @cindex lowering, of high-level objects in gexps
  7644. This mechanism is not limited to package and derivation
  7645. objects: @dfn{compilers} able to ``lower'' other high-level objects to
  7646. derivations or files in the store can be defined,
  7647. such that these objects can also be inserted
  7648. into gexps. For example, a useful type of high-level objects that can be
  7649. inserted in a gexp is ``file-like objects'', which make it easy to
  7650. add files to the store and to refer to them in
  7651. derivations and such (see @code{local-file} and @code{plain-file}
  7652. below).
  7653. To illustrate the idea, here is an example of a gexp:
  7654. @lisp
  7655. (define build-exp
  7656. #~(begin
  7657. (mkdir #$output)
  7658. (chdir #$output)
  7659. (symlink (string-append #$coreutils "/bin/ls")
  7660. "list-files")))
  7661. @end lisp
  7662. This gexp can be passed to @code{gexp->derivation}; we obtain a
  7663. derivation that builds a directory containing exactly one symlink to
  7664. @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
  7665. @lisp
  7666. (gexp->derivation "the-thing" build-exp)
  7667. @end lisp
  7668. As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
  7669. substituted to the reference to the @var{coreutils} package in the
  7670. actual build code, and @var{coreutils} is automatically made an input to
  7671. the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
  7672. output)}) is replaced by a string containing the directory name of the
  7673. output of the derivation.
  7674. @cindex cross compilation
  7675. In a cross-compilation context, it is useful to distinguish between
  7676. references to the @emph{native} build of a package---that can run on the
  7677. host---versus references to cross builds of a package. To that end, the
  7678. @code{#+} plays the same role as @code{#$}, but is a reference to a
  7679. native package build:
  7680. @lisp
  7681. (gexp->derivation "vi"
  7682. #~(begin
  7683. (mkdir #$output)
  7684. (mkdir (string-append #$output "/bin"))
  7685. (system* (string-append #+coreutils "/bin/ln")
  7686. "-s"
  7687. (string-append #$emacs "/bin/emacs")
  7688. (string-append #$output "/bin/vi")))
  7689. #:target "aarch64-linux-gnu")
  7690. @end lisp
  7691. @noindent
  7692. In the example above, the native build of @var{coreutils} is used, so
  7693. that @command{ln} can actually run on the host; but then the
  7694. cross-compiled build of @var{emacs} is referenced.
  7695. @cindex imported modules, for gexps
  7696. @findex with-imported-modules
  7697. Another gexp feature is @dfn{imported modules}: sometimes you want to be
  7698. able to use certain Guile modules from the ``host environment'' in the
  7699. gexp, so those modules should be imported in the ``build environment''.
  7700. The @code{with-imported-modules} form allows you to express that:
  7701. @lisp
  7702. (let ((build (with-imported-modules '((guix build utils))
  7703. #~(begin
  7704. (use-modules (guix build utils))
  7705. (mkdir-p (string-append #$output "/bin"))))))
  7706. (gexp->derivation "empty-dir"
  7707. #~(begin
  7708. #$build
  7709. (display "success!\n")
  7710. #t)))
  7711. @end lisp
  7712. @noindent
  7713. In this example, the @code{(guix build utils)} module is automatically
  7714. pulled into the isolated build environment of our gexp, such that
  7715. @code{(use-modules (guix build utils))} works as expected.
  7716. @cindex module closure
  7717. @findex source-module-closure
  7718. Usually you want the @emph{closure} of the module to be imported---i.e.,
  7719. the module itself and all the modules it depends on---rather than just
  7720. the module; failing to do that, attempts to use the module will fail
  7721. because of missing dependent modules. The @code{source-module-closure}
  7722. procedure computes the closure of a module by looking at its source file
  7723. headers, which comes in handy in this case:
  7724. @lisp
  7725. (use-modules (guix modules)) ;for 'source-module-closure'
  7726. (with-imported-modules (source-module-closure
  7727. '((guix build utils)
  7728. (gnu build vm)))
  7729. (gexp->derivation "something-with-vms"
  7730. #~(begin
  7731. (use-modules (guix build utils)
  7732. (gnu build vm))
  7733. @dots{})))
  7734. @end lisp
  7735. @cindex extensions, for gexps
  7736. @findex with-extensions
  7737. In the same vein, sometimes you want to import not just pure-Scheme
  7738. modules, but also ``extensions'' such as Guile bindings to C libraries
  7739. or other ``full-blown'' packages. Say you need the @code{guile-json}
  7740. package available on the build side, here's how you would do it:
  7741. @lisp
  7742. (use-modules (gnu packages guile)) ;for 'guile-json'
  7743. (with-extensions (list guile-json)
  7744. (gexp->derivation "something-with-json"
  7745. #~(begin
  7746. (use-modules (json))
  7747. @dots{})))
  7748. @end lisp
  7749. The syntactic form to construct gexps is summarized below.
  7750. @deffn {Scheme Syntax} #~@var{exp}
  7751. @deffnx {Scheme Syntax} (gexp @var{exp})
  7752. Return a G-expression containing @var{exp}. @var{exp} may contain one
  7753. or more of the following forms:
  7754. @table @code
  7755. @item #$@var{obj}
  7756. @itemx (ungexp @var{obj})
  7757. Introduce a reference to @var{obj}. @var{obj} may have one of the
  7758. supported types, for example a package or a
  7759. derivation, in which case the @code{ungexp} form is replaced by its
  7760. output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
  7761. If @var{obj} is a list, it is traversed and references to supported
  7762. objects are substituted similarly.
  7763. If @var{obj} is another gexp, its contents are inserted and its
  7764. dependencies are added to those of the containing gexp.
  7765. If @var{obj} is another kind of object, it is inserted as is.
  7766. @item #$@var{obj}:@var{output}
  7767. @itemx (ungexp @var{obj} @var{output})
  7768. This is like the form above, but referring explicitly to the
  7769. @var{output} of @var{obj}---this is useful when @var{obj} produces
  7770. multiple outputs (@pxref{Packages with Multiple Outputs}).
  7771. @item #+@var{obj}
  7772. @itemx #+@var{obj}:output
  7773. @itemx (ungexp-native @var{obj})
  7774. @itemx (ungexp-native @var{obj} @var{output})
  7775. Same as @code{ungexp}, but produces a reference to the @emph{native}
  7776. build of @var{obj} when used in a cross compilation context.
  7777. @item #$output[:@var{output}]
  7778. @itemx (ungexp output [@var{output}])
  7779. Insert a reference to derivation output @var{output}, or to the main
  7780. output when @var{output} is omitted.
  7781. This only makes sense for gexps passed to @code{gexp->derivation}.
  7782. @item #$@@@var{lst}
  7783. @itemx (ungexp-splicing @var{lst})
  7784. Like the above, but splices the contents of @var{lst} inside the
  7785. containing list.
  7786. @item #+@@@var{lst}
  7787. @itemx (ungexp-native-splicing @var{lst})
  7788. Like the above, but refers to native builds of the objects listed in
  7789. @var{lst}.
  7790. @end table
  7791. G-expressions created by @code{gexp} or @code{#~} are run-time objects
  7792. of the @code{gexp?} type (see below).
  7793. @end deffn
  7794. @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
  7795. Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
  7796. in their execution environment.
  7797. Each item in @var{modules} can be the name of a module, such as
  7798. @code{(guix build utils)}, or it can be a module name, followed by an
  7799. arrow, followed by a file-like object:
  7800. @lisp
  7801. `((guix build utils)
  7802. (guix gcrypt)
  7803. ((guix config) => ,(scheme-file "config.scm"
  7804. #~(define-module @dots{}))))
  7805. @end lisp
  7806. @noindent
  7807. In the example above, the first two modules are taken from the search
  7808. path, and the last one is created from the given file-like object.
  7809. This form has @emph{lexical} scope: it has an effect on the gexps
  7810. directly defined in @var{body}@dots{}, but not on those defined, say, in
  7811. procedures called from @var{body}@dots{}.
  7812. @end deffn
  7813. @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
  7814. Mark the gexps defined in @var{body}@dots{} as requiring
  7815. @var{extensions} in their build and execution environment.
  7816. @var{extensions} is typically a list of package objects such as those
  7817. defined in the @code{(gnu packages guile)} module.
  7818. Concretely, the packages listed in @var{extensions} are added to the
  7819. load path while compiling imported modules in @var{body}@dots{}; they
  7820. are also added to the load path of the gexp returned by
  7821. @var{body}@dots{}.
  7822. @end deffn
  7823. @deffn {Scheme Procedure} gexp? @var{obj}
  7824. Return @code{#t} if @var{obj} is a G-expression.
  7825. @end deffn
  7826. G-expressions are meant to be written to disk, either as code building
  7827. some derivation, or as plain files in the store. The monadic procedures
  7828. below allow you to do that (@pxref{The Store Monad}, for more
  7829. information about monads).
  7830. @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
  7831. [#:system (%current-system)] [#:target #f] [#:graft? #t] @
  7832. [#:hash #f] [#:hash-algo #f] @
  7833. [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
  7834. [#:module-path @code{%load-path}] @
  7835. [#:effective-version "2.2"] @
  7836. [#:references-graphs #f] [#:allowed-references #f] @
  7837. [#:disallowed-references #f] @
  7838. [#:leaked-env-vars #f] @
  7839. [#:script-name (string-append @var{name} "-builder")] @
  7840. [#:deprecation-warnings #f] @
  7841. [#:local-build? #f] [#:substitutable? #t] @
  7842. [#:properties '()] [#:guile-for-build #f]
  7843. Return a derivation @var{name} that runs @var{exp} (a gexp) with
  7844. @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
  7845. stored in a file called @var{script-name}. When @var{target} is true,
  7846. it is used as the cross-compilation target triplet for packages referred
  7847. to by @var{exp}.
  7848. @var{modules} is deprecated in favor of @code{with-imported-modules}.
  7849. Its meaning is to
  7850. make @var{modules} available in the evaluation context of @var{exp};
  7851. @var{modules} is a list of names of Guile modules searched in
  7852. @var{module-path} to be copied in the store, compiled, and made available in
  7853. the load path during the execution of @var{exp}---e.g., @code{((guix
  7854. build utils) (guix build gnu-build-system))}.
  7855. @var{effective-version} determines the string to use when adding extensions of
  7856. @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
  7857. @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
  7858. applicable.
  7859. When @var{references-graphs} is true, it must be a list of tuples of one of the
  7860. following forms:
  7861. @example
  7862. (@var{file-name} @var{package})
  7863. (@var{file-name} @var{package} @var{output})
  7864. (@var{file-name} @var{derivation})
  7865. (@var{file-name} @var{derivation} @var{output})
  7866. (@var{file-name} @var{store-item})
  7867. @end example
  7868. The right-hand-side of each element of @var{references-graphs} is automatically made
  7869. an input of the build process of @var{exp}. In the build environment, each
  7870. @var{file-name} contains the reference graph of the corresponding item, in a simple
  7871. text format.
  7872. @var{allowed-references} must be either @code{#f} or a list of output names and packages.
  7873. In the latter case, the list denotes store items that the result is allowed to
  7874. refer to. Any reference to another store item will lead to a build error.
  7875. Similarly for @var{disallowed-references}, which can list items that must not be
  7876. referenced by the outputs.
  7877. @var{deprecation-warnings} determines whether to show deprecation warnings while
  7878. compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
  7879. The other arguments are as for @code{derivation} (@pxref{Derivations}).
  7880. @end deffn
  7881. @cindex file-like objects
  7882. The @code{local-file}, @code{plain-file}, @code{computed-file},
  7883. @code{program-file}, and @code{scheme-file} procedures below return
  7884. @dfn{file-like objects}. That is, when unquoted in a G-expression,
  7885. these objects lead to a file in the store. Consider this G-expression:
  7886. @lisp
  7887. #~(system* #$(file-append glibc "/sbin/nscd") "-f"
  7888. #$(local-file "/tmp/my-nscd.conf"))
  7889. @end lisp
  7890. The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
  7891. to the store. Once expanded, for instance @i{via}
  7892. @code{gexp->derivation}, the G-expression refers to that copy under
  7893. @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
  7894. does not have any effect on what the G-expression does.
  7895. @code{plain-file} can be used similarly; it differs in that the file
  7896. content is directly passed as a string.
  7897. @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
  7898. [#:recursive? #f] [#:select? (const #t)]
  7899. Return an object representing local file @var{file} to add to the store;
  7900. this object can be used in a gexp. If @var{file} is a literal string
  7901. denoting a relative file name, it is looked up relative to the source
  7902. file where it appears; if @var{file} is not a literal string, it is
  7903. looked up relative to the current working directory at run time.
  7904. @var{file} will be added to the store under @var{name}--by default the
  7905. base name of @var{file}.
  7906. When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
  7907. designates a flat file and @var{recursive?} is true, its contents are added, and its
  7908. permission bits are kept.
  7909. When @var{recursive?} is true, call @code{(@var{select?} @var{file}
  7910. @var{stat})} for each directory entry, where @var{file} is the entry's
  7911. absolute file name and @var{stat} is the result of @code{lstat}; exclude
  7912. entries for which @var{select?} does not return true.
  7913. This is the declarative counterpart of the @code{interned-file} monadic
  7914. procedure (@pxref{The Store Monad, @code{interned-file}}).
  7915. @end deffn
  7916. @deffn {Scheme Procedure} plain-file @var{name} @var{content}
  7917. Return an object representing a text file called @var{name} with the given
  7918. @var{content} (a string or a bytevector) to be added to the store.
  7919. This is the declarative counterpart of @code{text-file}.
  7920. @end deffn
  7921. @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
  7922. [#:local-build? #t]
  7923. [#:options '()]
  7924. Return an object representing the store item @var{name}, a file or
  7925. directory computed by @var{gexp}. When @var{local-build?} is true (the
  7926. default), the derivation is built locally. @var{options} is a list of
  7927. additional arguments to pass to @code{gexp->derivation}.
  7928. This is the declarative counterpart of @code{gexp->derivation}.
  7929. @end deffn
  7930. @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
  7931. [#:guile (default-guile)] [#:module-path %load-path] @
  7932. [#:system (%current-system)] [#:target #f]
  7933. Return an executable script @var{name} that runs @var{exp} using
  7934. @var{guile}, with @var{exp}'s imported modules in its search path.
  7935. Look up @var{exp}'s modules in @var{module-path}.
  7936. The example below builds a script that simply invokes the @command{ls}
  7937. command:
  7938. @lisp
  7939. (use-modules (guix gexp) (gnu packages base))
  7940. (gexp->script "list-files"
  7941. #~(execl #$(file-append coreutils "/bin/ls")
  7942. "ls"))
  7943. @end lisp
  7944. When ``running'' it through the store (@pxref{The Store Monad,
  7945. @code{run-with-store}}), we obtain a derivation that produces an
  7946. executable file @file{/gnu/store/@dots{}-list-files} along these lines:
  7947. @example
  7948. #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
  7949. !#
  7950. (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
  7951. @end example
  7952. @end deffn
  7953. @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
  7954. [#:guile #f] [#:module-path %load-path]
  7955. Return an object representing the executable store item @var{name} that
  7956. runs @var{gexp}. @var{guile} is the Guile package used to execute that
  7957. script. Imported modules of @var{gexp} are looked up in @var{module-path}.
  7958. This is the declarative counterpart of @code{gexp->script}.
  7959. @end deffn
  7960. @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
  7961. [#:set-load-path? #t] [#:module-path %load-path] @
  7962. [#:splice? #f] @
  7963. [#:guile (default-guile)]
  7964. Return a derivation that builds a file @var{name} containing @var{exp}.
  7965. When @var{splice?} is true, @var{exp} is considered to be a list of
  7966. expressions that will be spliced in the resulting file.
  7967. When @var{set-load-path?} is true, emit code in the resulting file to
  7968. set @code{%load-path} and @code{%load-compiled-path} to honor
  7969. @var{exp}'s imported modules. Look up @var{exp}'s modules in
  7970. @var{module-path}.
  7971. The resulting file holds references to all the dependencies of @var{exp}
  7972. or a subset thereof.
  7973. @end deffn
  7974. @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
  7975. [#:splice? #f] [#:set-load-path? #t]
  7976. Return an object representing the Scheme file @var{name} that contains
  7977. @var{exp}.
  7978. This is the declarative counterpart of @code{gexp->file}.
  7979. @end deffn
  7980. @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
  7981. Return as a monadic value a derivation that builds a text file
  7982. containing all of @var{text}. @var{text} may list, in addition to
  7983. strings, objects of any type that can be used in a gexp: packages,
  7984. derivations, local file objects, etc. The resulting store file holds
  7985. references to all these.
  7986. This variant should be preferred over @code{text-file} anytime the file
  7987. to create will reference items from the store. This is typically the
  7988. case when building a configuration file that embeds store file names,
  7989. like this:
  7990. @lisp
  7991. (define (profile.sh)
  7992. ;; Return the name of a shell script in the store that
  7993. ;; initializes the 'PATH' environment variable.
  7994. (text-file* "profile.sh"
  7995. "export PATH=" coreutils "/bin:"
  7996. grep "/bin:" sed "/bin\n"))
  7997. @end lisp
  7998. In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
  7999. will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
  8000. preventing them from being garbage-collected during its lifetime.
  8001. @end deffn
  8002. @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
  8003. Return an object representing store file @var{name} containing
  8004. @var{text}. @var{text} is a sequence of strings and file-like objects,
  8005. as in:
  8006. @lisp
  8007. (mixed-text-file "profile"
  8008. "export PATH=" coreutils "/bin:" grep "/bin")
  8009. @end lisp
  8010. This is the declarative counterpart of @code{text-file*}.
  8011. @end deffn
  8012. @deffn {Scheme Procedure} file-union @var{name} @var{files}
  8013. Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
  8014. Each item in @var{files} must be a two-element list where the first element is the
  8015. file name to use in the new directory, and the second element is a gexp
  8016. denoting the target file. Here's an example:
  8017. @lisp
  8018. (file-union "etc"
  8019. `(("hosts" ,(plain-file "hosts"
  8020. "127.0.0.1 localhost"))
  8021. ("bashrc" ,(plain-file "bashrc"
  8022. "alias ls='ls --color=auto'"))))
  8023. @end lisp
  8024. This yields an @code{etc} directory containing these two files.
  8025. @end deffn
  8026. @deffn {Scheme Procedure} directory-union @var{name} @var{things}
  8027. Return a directory that is the union of @var{things}, where @var{things} is a list of
  8028. file-like objects denoting directories. For example:
  8029. @lisp
  8030. (directory-union "guile+emacs" (list guile emacs))
  8031. @end lisp
  8032. yields a directory that is the union of the @code{guile} and @code{emacs} packages.
  8033. @end deffn
  8034. @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
  8035. Return a file-like object that expands to the concatenation of @var{obj}
  8036. and @var{suffix}, where @var{obj} is a lowerable object and each
  8037. @var{suffix} is a string.
  8038. As an example, consider this gexp:
  8039. @lisp
  8040. (gexp->script "run-uname"
  8041. #~(system* #$(file-append coreutils
  8042. "/bin/uname")))
  8043. @end lisp
  8044. The same effect could be achieved with:
  8045. @lisp
  8046. (gexp->script "run-uname"
  8047. #~(system* (string-append #$coreutils
  8048. "/bin/uname")))
  8049. @end lisp
  8050. There is one difference though: in the @code{file-append} case, the
  8051. resulting script contains the absolute file name as a string, whereas in
  8052. the second case, the resulting script contains a @code{(string-append
  8053. @dots{})} expression to construct the file name @emph{at run time}.
  8054. @end deffn
  8055. @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
  8056. @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
  8057. Bind @var{system} to the currently targeted system---e.g.,
  8058. @code{"x86_64-linux"}---within @var{body}.
  8059. In the second case, additionally bind @var{target} to the current
  8060. cross-compilation target---a GNU triplet such as
  8061. @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
  8062. cross-compiling.
  8063. @code{let-system} is useful in the occasional case where the object
  8064. spliced into the gexp depends on the target system, as in this example:
  8065. @lisp
  8066. #~(system*
  8067. #+(let-system system
  8068. (cond ((string-prefix? "armhf-" system)
  8069. (file-append qemu "/bin/qemu-system-arm"))
  8070. ((string-prefix? "x86_64-" system)
  8071. (file-append qemu "/bin/qemu-system-x86_64"))
  8072. (else
  8073. (error "dunno!"))))
  8074. "-net" "user" #$image)
  8075. @end lisp
  8076. @end deffn
  8077. @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
  8078. This macro is similar to the @code{parameterize} form for
  8079. dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
  8080. Guile Reference Manual}). The key difference is that it takes effect
  8081. when the file-like object returned by @var{exp} is lowered to a
  8082. derivation or store item.
  8083. A typical use of @code{with-parameters} is to force the system in effect
  8084. for a given object:
  8085. @lisp
  8086. (with-parameters ((%current-system "i686-linux"))
  8087. coreutils)
  8088. @end lisp
  8089. The example above returns an object that corresponds to the i686 build
  8090. of Coreutils, regardless of the current value of @code{%current-system}.
  8091. @end deffn
  8092. Of course, in addition to gexps embedded in ``host'' code, there are
  8093. also modules containing build tools. To make it clear that they are
  8094. meant to be used in the build stratum, these modules are kept in the
  8095. @code{(guix build @dots{})} name space.
  8096. @cindex lowering, of high-level objects in gexps
  8097. Internally, high-level objects are @dfn{lowered}, using their compiler,
  8098. to either derivations or store items. For instance, lowering a package
  8099. yields a derivation, and lowering a @code{plain-file} yields a store
  8100. item. This is achieved using the @code{lower-object} monadic procedure.
  8101. @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
  8102. [#:target #f]
  8103. Return as a value in @code{%store-monad} the derivation or store item
  8104. corresponding to @var{obj} for @var{system}, cross-compiling for
  8105. @var{target} if @var{target} is true. @var{obj} must be an object that
  8106. has an associated gexp compiler, such as a @code{<package>}.
  8107. @end deffn
  8108. @node Invoking guix repl
  8109. @section Invoking @command{guix repl}
  8110. @cindex REPL, read-eval-print loop, script
  8111. The @command{guix repl} command makes it easier to program Guix in Guile
  8112. by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
  8113. programming (@pxref{Using Guile Interactively,,, guile,
  8114. GNU Guile Reference Manual}), or by running Guile scripts
  8115. (@pxref{Running Guile Scripts,,, guile,
  8116. GNU Guile Reference Manual}).
  8117. Compared to just launching the @command{guile}
  8118. command, @command{guix repl} guarantees that all the Guix modules and all its
  8119. dependencies are available in the search path.
  8120. The general syntax is:
  8121. @example
  8122. guix repl @var{options} [@var{file} @var{args}]
  8123. @end example
  8124. When a @var{file} argument is provided, @var{file} is
  8125. executed as a Guile scripts:
  8126. @example
  8127. guix repl my-script.scm
  8128. @end example
  8129. To pass arguments to the script, use @code{--} to prevent them from
  8130. being interpreted as arguments to @command{guix repl} itself:
  8131. @example
  8132. guix repl -- my-script.scm --input=foo.txt
  8133. @end example
  8134. To make a script executable directly from the shell, using the guix
  8135. executable that is on the user's search path, add the following two
  8136. lines at the top of the script:
  8137. @example
  8138. @code{#!/usr/bin/env -S guix repl --}
  8139. @code{!#}
  8140. @end example
  8141. Without a file name argument, a Guile REPL is started:
  8142. @example
  8143. $ guix repl
  8144. scheme@@(guile-user)> ,use (gnu packages base)
  8145. scheme@@(guile-user)> coreutils
  8146. $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
  8147. @end example
  8148. @cindex inferiors
  8149. In addition, @command{guix repl} implements a simple machine-readable REPL
  8150. protocol for use by @code{(guix inferior)}, a facility to interact with
  8151. @dfn{inferiors}, separate processes running a potentially different revision
  8152. of Guix.
  8153. The available options are as follows:
  8154. @table @code
  8155. @item --type=@var{type}
  8156. @itemx -t @var{type}
  8157. Start a REPL of the given @var{TYPE}, which can be one of the following:
  8158. @table @code
  8159. @item guile
  8160. This is default, and it spawns a standard full-featured Guile REPL.
  8161. @item machine
  8162. Spawn a REPL that uses the machine-readable protocol. This is the protocol
  8163. that the @code{(guix inferior)} module speaks.
  8164. @end table
  8165. @item --listen=@var{endpoint}
  8166. By default, @command{guix repl} reads from standard input and writes to
  8167. standard output. When this option is passed, it will instead listen for
  8168. connections on @var{endpoint}. Here are examples of valid options:
  8169. @table @code
  8170. @item --listen=tcp:37146
  8171. Accept connections on localhost on port 37146.
  8172. @item --listen=unix:/tmp/socket
  8173. Accept connections on the Unix-domain socket @file{/tmp/socket}.
  8174. @end table
  8175. @item --load-path=@var{directory}
  8176. @itemx -L @var{directory}
  8177. Add @var{directory} to the front of the package module search path
  8178. (@pxref{Package Modules}).
  8179. This allows users to define their own packages and make them visible to
  8180. the script or REPL.
  8181. @item -q
  8182. Inhibit loading of the @file{~/.guile} file. By default, that
  8183. configuration file is loaded when spawning a @code{guile} REPL.
  8184. @end table
  8185. @include substituters.texi
  8186. @c *********************************************************************
  8187. @node Utilities
  8188. @chapter Utilities
  8189. This section describes Guix command-line utilities. Some of them are
  8190. primarily targeted at developers and users who write new package
  8191. definitions, while others are more generally useful. They complement
  8192. the Scheme programming interface of Guix in a convenient way.
  8193. @menu
  8194. * Invoking guix build:: Building packages from the command line.
  8195. * Invoking guix edit:: Editing package definitions.
  8196. * Invoking guix download:: Downloading a file and printing its hash.
  8197. * Invoking guix hash:: Computing the cryptographic hash of a file.
  8198. * Invoking guix import:: Importing package definitions.
  8199. * Invoking guix refresh:: Updating package definitions.
  8200. * Invoking guix lint:: Finding errors in package definitions.
  8201. * Invoking guix size:: Profiling disk usage.
  8202. * Invoking guix graph:: Visualizing the graph of packages.
  8203. * Invoking guix publish:: Sharing substitutes.
  8204. * Invoking guix challenge:: Challenging substitute servers.
  8205. * Invoking guix copy:: Copying to and from a remote store.
  8206. * Invoking guix container:: Process isolation.
  8207. * Invoking guix weather:: Assessing substitute availability.
  8208. * Invoking guix processes:: Listing client processes.
  8209. @end menu
  8210. @node Invoking guix build
  8211. @section Invoking @command{guix build}
  8212. @cindex package building
  8213. @cindex @command{guix build}
  8214. The @command{guix build} command builds packages or derivations and
  8215. their dependencies, and prints the resulting store paths. Note that it
  8216. does not modify the user's profile---this is the job of the
  8217. @command{guix package} command (@pxref{Invoking guix package}). Thus,
  8218. it is mainly useful for distribution developers.
  8219. The general syntax is:
  8220. @example
  8221. guix build @var{options} @var{package-or-derivation}@dots{}
  8222. @end example
  8223. As an example, the following command builds the latest versions of Emacs
  8224. and of Guile, displays their build logs, and finally displays the
  8225. resulting directories:
  8226. @example
  8227. guix build emacs guile
  8228. @end example
  8229. Similarly, the following command builds all the available packages:
  8230. @example
  8231. guix build --quiet --keep-going \
  8232. `guix package -A | cut -f1,2 --output-delimiter=@@`
  8233. @end example
  8234. @var{package-or-derivation} may be either the name of a package found in
  8235. the software distribution such as @code{coreutils} or
  8236. @code{coreutils@@8.20}, or a derivation such as
  8237. @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
  8238. package with the corresponding name (and optionally version) is searched
  8239. for among the GNU distribution modules (@pxref{Package Modules}).
  8240. Alternatively, the @option{--expression} option may be used to specify a
  8241. Scheme expression that evaluates to a package; this is useful when
  8242. disambiguating among several same-named packages or package variants is
  8243. needed.
  8244. There may be zero or more @var{options}. The available options are
  8245. described in the subsections below.
  8246. @menu
  8247. * Common Build Options:: Build options for most commands.
  8248. * Package Transformation Options:: Creating variants of packages.
  8249. * Additional Build Options:: Options specific to 'guix build'.
  8250. * Debugging Build Failures:: Real life packaging experience.
  8251. @end menu
  8252. @node Common Build Options
  8253. @subsection Common Build Options
  8254. A number of options that control the build process are common to
  8255. @command{guix build} and other commands that can spawn builds, such as
  8256. @command{guix package} or @command{guix archive}. These are the
  8257. following:
  8258. @table @code
  8259. @item --load-path=@var{directory}
  8260. @itemx -L @var{directory}
  8261. Add @var{directory} to the front of the package module search path
  8262. (@pxref{Package Modules}).
  8263. This allows users to define their own packages and make them visible to
  8264. the command-line tools.
  8265. @item --keep-failed
  8266. @itemx -K
  8267. Keep the build tree of failed builds. Thus, if a build fails, its build
  8268. tree is kept under @file{/tmp}, in a directory whose name is shown at
  8269. the end of the build log. This is useful when debugging build issues.
  8270. @xref{Debugging Build Failures}, for tips and tricks on how to debug
  8271. build issues.
  8272. This option implies @option{--no-offload}, and it has no effect when
  8273. connecting to a remote daemon with a @code{guix://} URI (@pxref{The
  8274. Store, the @env{GUIX_DAEMON_SOCKET} variable}).
  8275. @item --keep-going
  8276. @itemx -k
  8277. Keep going when some of the derivations fail to build; return only once
  8278. all the builds have either completed or failed.
  8279. The default behavior is to stop as soon as one of the specified
  8280. derivations has failed.
  8281. @item --dry-run
  8282. @itemx -n
  8283. Do not build the derivations.
  8284. @anchor{fallback-option}
  8285. @item --fallback
  8286. When substituting a pre-built binary fails, fall back to building
  8287. packages locally (@pxref{Substitution Failure}).
  8288. @item --substitute-urls=@var{urls}
  8289. @anchor{client-substitute-urls}
  8290. Consider @var{urls} the whitespace-separated list of substitute source
  8291. URLs, overriding the default list of URLs of @command{guix-daemon}
  8292. (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
  8293. This means that substitutes may be downloaded from @var{urls}, provided
  8294. they are signed by a key authorized by the system administrator
  8295. (@pxref{Substitutes}).
  8296. When @var{urls} is the empty string, substitutes are effectively
  8297. disabled.
  8298. @item --no-substitutes
  8299. Do not use substitutes for build products. That is, always build things
  8300. locally instead of allowing downloads of pre-built binaries
  8301. (@pxref{Substitutes}).
  8302. @item --no-grafts
  8303. Do not ``graft'' packages. In practice, this means that package updates
  8304. available as grafts are not applied. @xref{Security Updates}, for more
  8305. information on grafts.
  8306. @item --rounds=@var{n}
  8307. Build each derivation @var{n} times in a row, and raise an error if
  8308. consecutive build results are not bit-for-bit identical.
  8309. This is a useful way to detect non-deterministic builds processes.
  8310. Non-deterministic build processes are a problem because they make it
  8311. practically impossible for users to @emph{verify} whether third-party
  8312. binaries are genuine. @xref{Invoking guix challenge}, for more.
  8313. When used in conjunction with @option{--keep-failed}, the differing
  8314. output is kept in the store, under @file{/gnu/store/@dots{}-check}.
  8315. This makes it easy to look for differences between the two results.
  8316. @item --no-offload
  8317. Do not use offload builds to other machines (@pxref{Daemon Offload
  8318. Setup}). That is, always build things locally instead of offloading
  8319. builds to remote machines.
  8320. @item --max-silent-time=@var{seconds}
  8321. When the build or substitution process remains silent for more than
  8322. @var{seconds}, terminate it and report a build failure.
  8323. By default, the daemon's setting is honored (@pxref{Invoking
  8324. guix-daemon, @option{--max-silent-time}}).
  8325. @item --timeout=@var{seconds}
  8326. Likewise, when the build or substitution process lasts for more than
  8327. @var{seconds}, terminate it and report a build failure.
  8328. By default, the daemon's setting is honored (@pxref{Invoking
  8329. guix-daemon, @option{--timeout}}).
  8330. @c Note: This option is actually not part of %standard-build-options but
  8331. @c most programs honor it.
  8332. @cindex verbosity, of the command-line tools
  8333. @cindex build logs, verbosity
  8334. @item -v @var{level}
  8335. @itemx --verbosity=@var{level}
  8336. Use the given verbosity @var{level}, an integer. Choosing 0 means that no
  8337. output is produced, 1 is for quiet output, and 2 shows all the build log
  8338. output on standard error.
  8339. @item --cores=@var{n}
  8340. @itemx -c @var{n}
  8341. Allow the use of up to @var{n} CPU cores for the build. The special
  8342. value @code{0} means to use as many CPU cores as available.
  8343. @item --max-jobs=@var{n}
  8344. @itemx -M @var{n}
  8345. Allow at most @var{n} build jobs in parallel. @xref{Invoking
  8346. guix-daemon, @option{--max-jobs}}, for details about this option and the
  8347. equivalent @command{guix-daemon} option.
  8348. @item --debug=@var{level}
  8349. Produce debugging output coming from the build daemon. @var{level} must be an
  8350. integer between 0 and 5; higher means more verbose output. Setting a level of
  8351. 4 or more may be helpful when debugging setup issues with the build daemon.
  8352. @end table
  8353. Behind the scenes, @command{guix build} is essentially an interface to
  8354. the @code{package-derivation} procedure of the @code{(guix packages)}
  8355. module, and to the @code{build-derivations} procedure of the @code{(guix
  8356. derivations)} module.
  8357. In addition to options explicitly passed on the command line,
  8358. @command{guix build} and other @command{guix} commands that support
  8359. building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
  8360. @defvr {Environment Variable} GUIX_BUILD_OPTIONS
  8361. Users can define this variable to a list of command line options that
  8362. will automatically be used by @command{guix build} and other
  8363. @command{guix} commands that can perform builds, as in the example
  8364. below:
  8365. @example
  8366. $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
  8367. @end example
  8368. These options are parsed independently, and the result is appended to
  8369. the parsed command-line options.
  8370. @end defvr
  8371. @node Package Transformation Options
  8372. @subsection Package Transformation Options
  8373. @cindex package variants
  8374. Another set of command-line options supported by @command{guix build}
  8375. and also @command{guix package} are @dfn{package transformation
  8376. options}. These are options that make it possible to define @dfn{package
  8377. variants}---for instance, packages built from different source code.
  8378. This is a convenient way to create customized packages on the fly
  8379. without having to type in the definitions of package variants
  8380. (@pxref{Defining Packages}).
  8381. Package transformation options are preserved across upgrades:
  8382. @command{guix upgrade} attempts to apply transformation options
  8383. initially used when creating the profile to the upgraded packages.
  8384. The available options are listed below. Most commands support them and
  8385. also support a @option{--help-transform} option that lists all the
  8386. available options and a synopsis (these options are not shown in the
  8387. @option{--help} output for brevity).
  8388. @table @code
  8389. @item --with-source=@var{source}
  8390. @itemx --with-source=@var{package}=@var{source}
  8391. @itemx --with-source=@var{package}@@@var{version}=@var{source}
  8392. Use @var{source} as the source of @var{package}, and @var{version} as
  8393. its version number.
  8394. @var{source} must be a file name or a URL, as for @command{guix
  8395. download} (@pxref{Invoking guix download}).
  8396. When @var{package} is omitted,
  8397. it is taken to be the package name specified on the
  8398. command line that matches the base of @var{source}---e.g.,
  8399. if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
  8400. package is @code{guile}.
  8401. Likewise, when @var{version} is omitted, the version string is inferred from
  8402. @var{source}; in the previous example, it is @code{2.0.10}.
  8403. This option allows users to try out versions of packages other than the
  8404. one provided by the distribution. The example below downloads
  8405. @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
  8406. the @code{ed} package:
  8407. @example
  8408. guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
  8409. @end example
  8410. As a developer, @option{--with-source} makes it easy to test release
  8411. candidates:
  8412. @example
  8413. guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
  8414. @end example
  8415. @dots{} or to build from a checkout in a pristine environment:
  8416. @example
  8417. $ git clone git://git.sv.gnu.org/guix.git
  8418. $ guix build guix --with-source=guix@@1.0=./guix
  8419. @end example
  8420. @item --with-input=@var{package}=@var{replacement}
  8421. Replace dependency on @var{package} by a dependency on
  8422. @var{replacement}. @var{package} must be a package name, and
  8423. @var{replacement} must be a package specification such as @code{guile}
  8424. or @code{guile@@1.8}.
  8425. For instance, the following command builds Guix, but replaces its
  8426. dependency on the current stable version of Guile with a dependency on
  8427. the legacy version of Guile, @code{guile@@2.0}:
  8428. @example
  8429. guix build --with-input=guile=guile@@2.0 guix
  8430. @end example
  8431. This is a recursive, deep replacement. So in this example, both
  8432. @code{guix} and its dependency @code{guile-json} (which also depends on
  8433. @code{guile}) get rebuilt against @code{guile@@2.0}.
  8434. This is implemented using the @code{package-input-rewriting} Scheme
  8435. procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
  8436. @item --with-graft=@var{package}=@var{replacement}
  8437. This is similar to @option{--with-input} but with an important difference:
  8438. instead of rebuilding the whole dependency chain, @var{replacement} is
  8439. built and then @dfn{grafted} onto the binaries that were initially
  8440. referring to @var{package}. @xref{Security Updates}, for more
  8441. information on grafts.
  8442. For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
  8443. and all its dependencies, replacing references to the version of GnuTLS
  8444. they currently refer to:
  8445. @example
  8446. guix build --with-graft=gnutls=gnutls@@3.5.4 wget
  8447. @end example
  8448. This has the advantage of being much faster than rebuilding everything.
  8449. But there is a caveat: it works if and only if @var{package} and
  8450. @var{replacement} are strictly compatible---for example, if they provide
  8451. a library, the application binary interface (ABI) of those libraries
  8452. must be compatible. If @var{replacement} is somehow incompatible with
  8453. @var{package}, then the resulting package may be unusable. Use with
  8454. care!
  8455. @cindex debugging info, rebuilding
  8456. @item --with-debug-info=@var{package}
  8457. Build @var{package} in a way that preserves its debugging info and graft
  8458. it onto packages that depend on it. This is useful if @var{package}
  8459. does not already provide debugging info as a @code{debug} output
  8460. (@pxref{Installing Debugging Files}).
  8461. For example, suppose you're experiencing a crash in Inkscape and would
  8462. like to see what's up in GLib, a library deep down in Inkscape's
  8463. dependency graph. GLib lacks a @code{debug} output, so debugging is
  8464. tough. Fortunately, you rebuild GLib with debugging info and tack it on
  8465. Inkscape:
  8466. @example
  8467. guix install inkscape --with-debug-info=glib
  8468. @end example
  8469. Only GLib needs to be recompiled so this takes a reasonable amount of
  8470. time. @xref{Installing Debugging Files}, for more info.
  8471. @quotation Note
  8472. Under the hood, this option works by passing the @samp{#:strip-binaries?
  8473. #f} to the build system of the package of interest (@pxref{Build
  8474. Systems}). Most build systems support that option but some do not. In
  8475. that case, an error is raised.
  8476. Likewise, if a C/C++ package is built without @code{-g} (which is rarely
  8477. the case), debugging info will remain unavailable even when
  8478. @code{#:strip-binaries?} is false.
  8479. @end quotation
  8480. @cindex tool chain, changing the build tool chain of a package
  8481. @item --with-c-toolchain=@var{package}=@var{toolchain}
  8482. This option changes the compilation of @var{package} and everything that
  8483. depends on it so that they get built with @var{toolchain} instead of the
  8484. default GNU tool chain for C/C++.
  8485. Consider this example:
  8486. @example
  8487. guix build octave-cli \
  8488. --with-c-toolchain=fftw=gcc-toolchain@@10 \
  8489. --with-c-toolchain=fftwf=gcc-toolchain@@10
  8490. @end example
  8491. The command above builds a variant of the @code{fftw} and @code{fftwf}
  8492. packages using version 10 of @code{gcc-toolchain} instead of the default
  8493. tool chain, and then builds a variant of the GNU@tie{}Octave
  8494. command-line interface using them. GNU@tie{}Octave itself is also built
  8495. with @code{gcc-toolchain@@10}.
  8496. This other example builds the Hardware Locality (@code{hwloc}) library
  8497. and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
  8498. compiler:
  8499. @example
  8500. guix build --with-c-toolchain=hwloc=clang-toolchain \
  8501. intel-mpi-benchmarks
  8502. @end example
  8503. @quotation Note
  8504. There can be application binary interface (ABI) incompatibilities among
  8505. tool chains. This is particularly true of the C++ standard library and
  8506. run-time support libraries such as that of OpenMP@. By rebuilding all
  8507. dependents with the same tool chain, @option{--with-c-toolchain} minimizes
  8508. the risks of incompatibility but cannot entirely eliminate them. Choose
  8509. @var{package} wisely.
  8510. @end quotation
  8511. @item --with-git-url=@var{package}=@var{url}
  8512. @cindex Git, using the latest commit
  8513. @cindex latest commit, building
  8514. Build @var{package} from the latest commit of the @code{master} branch of the
  8515. Git repository at @var{url}. Git sub-modules of the repository are fetched,
  8516. recursively.
  8517. For example, the following command builds the NumPy Python library against the
  8518. latest commit of the master branch of Python itself:
  8519. @example
  8520. guix build python-numpy \
  8521. --with-git-url=python=https://github.com/python/cpython
  8522. @end example
  8523. This option can also be combined with @option{--with-branch} or
  8524. @option{--with-commit} (see below).
  8525. @cindex continuous integration
  8526. Obviously, since it uses the latest commit of the given branch, the result of
  8527. such a command varies over time. Nevertheless it is a convenient way to
  8528. rebuild entire software stacks against the latest commit of one or more
  8529. packages. This is particularly useful in the context of continuous
  8530. integration (CI).
  8531. Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
  8532. consecutive accesses to the same repository. You may want to clean it up once
  8533. in a while to save disk space.
  8534. @item --with-branch=@var{package}=@var{branch}
  8535. Build @var{package} from the latest commit of @var{branch}. If the
  8536. @code{source} field of @var{package} is an origin with the @code{git-fetch}
  8537. method (@pxref{origin Reference}) or a @code{git-checkout} object, the
  8538. repository URL is taken from that @code{source}. Otherwise you have to use
  8539. @option{--with-git-url} to specify the URL of the Git repository.
  8540. For instance, the following command builds @code{guile-sqlite3} from the
  8541. latest commit of its @code{master} branch, and then builds @code{guix} (which
  8542. depends on it) and @code{cuirass} (which depends on @code{guix}) against this
  8543. specific @code{guile-sqlite3} build:
  8544. @example
  8545. guix build --with-branch=guile-sqlite3=master cuirass
  8546. @end example
  8547. @item --with-commit=@var{package}=@var{commit}
  8548. This is similar to @option{--with-branch}, except that it builds from
  8549. @var{commit} rather than the tip of a branch. @var{commit} must be a valid
  8550. Git commit SHA1 identifier or a tag.
  8551. @item --with-patch=@var{package}=@var{file}
  8552. Add @var{file} to the list of patches applied to @var{package}, where
  8553. @var{package} is a spec such as @code{python@@3.8} or @code{glibc}.
  8554. @var{file} must contain a patch; it is applied with the flags specified
  8555. in the @code{origin} of @var{package} (@pxref{origin Reference}), which
  8556. by default includes @code{-p1} (@pxref{patch Directories,,, diffutils,
  8557. Comparing and Merging Files}).
  8558. As an example, the command below rebuilds Coreutils with the GNU C
  8559. Library (glibc) patched with the given patch:
  8560. @example
  8561. guix build coreutils --with-patch=glibc=./glibc-frob.patch
  8562. @end example
  8563. In this example, glibc itself as well as everything that leads to
  8564. Coreutils in the dependency graph is rebuilt.
  8565. @cindex upstream, latest version
  8566. @item --with-latest=@var{package}
  8567. So you like living on the bleeding edge? This option is for you! It
  8568. replaces occurrences of @var{package} in the dependency graph with its
  8569. latest upstream version, as reported by @command{guix refresh}
  8570. (@pxref{Invoking guix refresh}).
  8571. It does so by determining the latest upstream release of @var{package}
  8572. (if possible), downloading it, and authenticating it @emph{if} it comes
  8573. with an OpenPGP signature.
  8574. As an example, the command below builds Guix against the latest version
  8575. of Guile-JSON:
  8576. @example
  8577. guix build guix --with-latest=guile-json
  8578. @end example
  8579. There are limitations. First, in cases where the tool cannot or does
  8580. not know how to authenticate source code, you are at risk of running
  8581. malicious code; a warning is emitted in this case. Second, this option
  8582. simply changes the source used in the existing package definitions,
  8583. which is not always sufficient: there might be additional dependencies
  8584. that need to be added, patches to apply, and more generally the quality
  8585. assurance work that Guix developers normally do will be missing.
  8586. You've been warned! In all the other cases, it's a snappy way to stay
  8587. on top. We encourage you to submit patches updating the actual package
  8588. definitions once you have successfully tested an upgrade
  8589. (@pxref{Contributing}).
  8590. @cindex test suite, skipping
  8591. @item --without-tests=@var{package}
  8592. Build @var{package} without running its tests. This can be useful in
  8593. situations where you want to skip the lengthy test suite of a
  8594. intermediate package, or if a package's test suite fails in a
  8595. non-deterministic fashion. It should be used with care because running
  8596. the test suite is a good way to ensure a package is working as intended.
  8597. Turning off tests leads to a different store item. Consequently, when
  8598. using this option, anything that depends on @var{package} must be
  8599. rebuilt, as in this example:
  8600. @example
  8601. guix install --without-tests=python python-notebook
  8602. @end example
  8603. The command above installs @code{python-notebook} on top of
  8604. @code{python} built without running its test suite. To do so, it also
  8605. rebuilds everything that depends on @code{python}, including
  8606. @code{python-notebook} itself.
  8607. Internally, @option{--without-tests} relies on changing the
  8608. @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
  8609. Systems}). Note that some packages use a customized @code{check} phase
  8610. that does not respect a @code{#:tests? #f} setting. Therefore,
  8611. @option{--without-tests} has no effect on these packages.
  8612. @end table
  8613. Wondering how to achieve the same effect using Scheme code, for example
  8614. in your manifest, or how to write your own package transformation?
  8615. @xref{Defining Package Variants}, for an overview of the programming
  8616. interfaces available.
  8617. @node Additional Build Options
  8618. @subsection Additional Build Options
  8619. The command-line options presented below are specific to @command{guix
  8620. build}.
  8621. @table @code
  8622. @item --quiet
  8623. @itemx -q
  8624. Build quietly, without displaying the build log; this is equivalent to
  8625. @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
  8626. (or similar) and can always be retrieved using the @option{--log-file} option.
  8627. @item --file=@var{file}
  8628. @itemx -f @var{file}
  8629. Build the package, derivation, or other file-like object that the code within
  8630. @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
  8631. As an example, @var{file} might contain a package definition like this
  8632. (@pxref{Defining Packages}):
  8633. @lisp
  8634. @include package-hello.scm
  8635. @end lisp
  8636. The @var{file} may also contain a JSON representation of one or more
  8637. package definitions. Running @code{guix build -f} on @file{hello.json}
  8638. with the following contents would result in building the packages
  8639. @code{myhello} and @code{greeter}:
  8640. @example
  8641. @verbatiminclude package-hello.json
  8642. @end example
  8643. @item --manifest=@var{manifest}
  8644. @itemx -m @var{manifest}
  8645. Build all packages listed in the given @var{manifest}
  8646. (@pxref{profile-manifest, @option{--manifest}}).
  8647. @item --expression=@var{expr}
  8648. @itemx -e @var{expr}
  8649. Build the package or derivation @var{expr} evaluates to.
  8650. For example, @var{expr} may be @code{(@@ (gnu packages guile)
  8651. guile-1.8)}, which unambiguously designates this specific variant of
  8652. version 1.8 of Guile.
  8653. Alternatively, @var{expr} may be a G-expression, in which case it is used
  8654. as a build program passed to @code{gexp->derivation}
  8655. (@pxref{G-Expressions}).
  8656. Lastly, @var{expr} may refer to a zero-argument monadic procedure
  8657. (@pxref{The Store Monad}). The procedure must return a derivation as a
  8658. monadic value, which is then passed through @code{run-with-store}.
  8659. @item --source
  8660. @itemx -S
  8661. Build the source derivations of the packages, rather than the packages
  8662. themselves.
  8663. For instance, @code{guix build -S gcc} returns something like
  8664. @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
  8665. source tarball.
  8666. The returned source tarball is the result of applying any patches and
  8667. code snippets specified in the package @code{origin} (@pxref{Defining
  8668. Packages}).
  8669. @cindex source, verification
  8670. As with other derivations, the result of building a source derivation
  8671. can be verified using the @option{--check} option (@pxref{build-check}).
  8672. This is useful to validate that a (potentially already built or
  8673. substituted, thus cached) package source matches against its declared
  8674. hash.
  8675. Note that @command{guix build -S} compiles the sources only of the
  8676. specified packages. They do not include the sources of statically
  8677. linked dependencies and by themselves are insufficient for reproducing
  8678. the packages.
  8679. @item --sources
  8680. Fetch and return the source of @var{package-or-derivation} and all their
  8681. dependencies, recursively. This is a handy way to obtain a local copy
  8682. of all the source code needed to build @var{packages}, allowing you to
  8683. eventually build them even without network access. It is an extension
  8684. of the @option{--source} option and can accept one of the following
  8685. optional argument values:
  8686. @table @code
  8687. @item package
  8688. This value causes the @option{--sources} option to behave in the same way
  8689. as the @option{--source} option.
  8690. @item all
  8691. Build the source derivations of all packages, including any source that
  8692. might be listed as @code{inputs}. This is the default value.
  8693. @example
  8694. $ guix build --sources tzdata
  8695. The following derivations will be built:
  8696. /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
  8697. /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
  8698. @end example
  8699. @item transitive
  8700. Build the source derivations of all packages, as well of all transitive
  8701. inputs to the packages. This can be used e.g.@: to
  8702. prefetch package source for later offline building.
  8703. @example
  8704. $ guix build --sources=transitive tzdata
  8705. The following derivations will be built:
  8706. /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
  8707. /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
  8708. /gnu/store/@dots{}-grep-2.21.tar.xz.drv
  8709. /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
  8710. /gnu/store/@dots{}-make-4.1.tar.xz.drv
  8711. /gnu/store/@dots{}-bash-4.3.tar.xz.drv
  8712. @dots{}
  8713. @end example
  8714. @end table
  8715. @item --system=@var{system}
  8716. @itemx -s @var{system}
  8717. Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
  8718. the system type of the build host. The @command{guix build} command allows
  8719. you to repeat this option several times, in which case it builds for all the
  8720. specified systems; other commands ignore extraneous @option{-s} options.
  8721. @quotation Note
  8722. The @option{--system} flag is for @emph{native} compilation and must not
  8723. be confused with cross-compilation. See @option{--target} below for
  8724. information on cross-compilation.
  8725. @end quotation
  8726. An example use of this is on Linux-based systems, which can emulate
  8727. different personalities. For instance, passing
  8728. @option{--system=i686-linux} on an @code{x86_64-linux} system or
  8729. @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
  8730. you to build packages in a complete 32-bit environment.
  8731. @quotation Note
  8732. Building for an @code{armhf-linux} system is unconditionally enabled on
  8733. @code{aarch64-linux} machines, although certain aarch64 chipsets do not
  8734. allow for this functionality, notably the ThunderX.
  8735. @end quotation
  8736. Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
  8737. is enabled (@pxref{Virtualization Services,
  8738. @code{qemu-binfmt-service-type}}), you can build for any system for
  8739. which a QEMU @code{binfmt_misc} handler is installed.
  8740. Builds for a system other than that of the machine you are using can
  8741. also be offloaded to a remote machine of the right architecture.
  8742. @xref{Daemon Offload Setup}, for more information on offloading.
  8743. @item --target=@var{triplet}
  8744. @cindex cross-compilation
  8745. Cross-build for @var{triplet}, which must be a valid GNU triplet, such
  8746. as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
  8747. configuration triplets,, autoconf, Autoconf}).
  8748. @anchor{build-check}
  8749. @item --check
  8750. @cindex determinism, checking
  8751. @cindex reproducibility, checking
  8752. Rebuild @var{package-or-derivation}, which are already available in the
  8753. store, and raise an error if the build results are not bit-for-bit
  8754. identical.
  8755. This mechanism allows you to check whether previously installed
  8756. substitutes are genuine (@pxref{Substitutes}), or whether the build result
  8757. of a package is deterministic. @xref{Invoking guix challenge}, for more
  8758. background information and tools.
  8759. When used in conjunction with @option{--keep-failed}, the differing
  8760. output is kept in the store, under @file{/gnu/store/@dots{}-check}.
  8761. This makes it easy to look for differences between the two results.
  8762. @item --repair
  8763. @cindex repairing store items
  8764. @cindex corruption, recovering from
  8765. Attempt to repair the specified store items, if they are corrupt, by
  8766. re-downloading or rebuilding them.
  8767. This operation is not atomic and thus restricted to @code{root}.
  8768. @item --derivations
  8769. @itemx -d
  8770. Return the derivation paths, not the output paths, of the given
  8771. packages.
  8772. @item --root=@var{file}
  8773. @itemx -r @var{file}
  8774. @cindex GC roots, adding
  8775. @cindex garbage collector roots, adding
  8776. Make @var{file} a symlink to the result, and register it as a garbage
  8777. collector root.
  8778. Consequently, the results of this @command{guix build} invocation are
  8779. protected from garbage collection until @var{file} is removed. When
  8780. that option is omitted, build results are eligible for garbage
  8781. collection as soon as the build completes. @xref{Invoking guix gc}, for
  8782. more on GC roots.
  8783. @item --log-file
  8784. @cindex build logs, access
  8785. Return the build log file names or URLs for the given
  8786. @var{package-or-derivation}, or raise an error if build logs are
  8787. missing.
  8788. This works regardless of how packages or derivations are specified. For
  8789. instance, the following invocations are equivalent:
  8790. @example
  8791. guix build --log-file `guix build -d guile`
  8792. guix build --log-file `guix build guile`
  8793. guix build --log-file guile
  8794. guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
  8795. @end example
  8796. If a log is unavailable locally, and unless @option{--no-substitutes} is
  8797. passed, the command looks for a corresponding log on one of the
  8798. substitute servers (as specified with @option{--substitute-urls}).
  8799. So for instance, imagine you want to see the build log of GDB on MIPS,
  8800. but you are actually on an @code{x86_64} machine:
  8801. @example
  8802. $ guix build --log-file gdb -s aarch64-linux
  8803. https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
  8804. @end example
  8805. You can freely access a huge library of build logs!
  8806. @end table
  8807. @node Debugging Build Failures
  8808. @subsection Debugging Build Failures
  8809. @cindex build failures, debugging
  8810. When defining a new package (@pxref{Defining Packages}), you will
  8811. probably find yourself spending some time debugging and tweaking the
  8812. build until it succeeds. To do that, you need to operate the build
  8813. commands yourself in an environment as close as possible to the one the
  8814. build daemon uses.
  8815. To that end, the first thing to do is to use the @option{--keep-failed}
  8816. or @option{-K} option of @command{guix build}, which will keep the
  8817. failed build tree in @file{/tmp} or whatever directory you specified as
  8818. @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
  8819. From there on, you can @command{cd} to the failed build tree and source
  8820. the @file{environment-variables} file, which contains all the
  8821. environment variable definitions that were in place when the build
  8822. failed. So let's say you're debugging a build failure in package
  8823. @code{foo}; a typical session would look like this:
  8824. @example
  8825. $ guix build foo -K
  8826. @dots{} @i{build fails}
  8827. $ cd /tmp/guix-build-foo.drv-0
  8828. $ source ./environment-variables
  8829. $ cd foo-1.2
  8830. @end example
  8831. Now, you can invoke commands as if you were the daemon (almost) and
  8832. troubleshoot your build process.
  8833. Sometimes it happens that, for example, a package's tests pass when you
  8834. run them manually but they fail when the daemon runs them. This can
  8835. happen because the daemon runs builds in containers where, unlike in our
  8836. environment above, network access is missing, @file{/bin/sh} does not
  8837. exist, etc. (@pxref{Build Environment Setup}).
  8838. In such cases, you may need to run inspect the build process from within
  8839. a container similar to the one the build daemon creates:
  8840. @example
  8841. $ guix build -K foo
  8842. @dots{}
  8843. $ cd /tmp/guix-build-foo.drv-0
  8844. $ guix environment --no-grafts -C foo --ad-hoc strace gdb
  8845. [env]# source ./environment-variables
  8846. [env]# cd foo-1.2
  8847. @end example
  8848. Here, @command{guix environment -C} creates a container and spawns a new
  8849. shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
  8850. strace gdb} part adds the @command{strace} and @command{gdb} commands to
  8851. the container, which you may find handy while debugging. The
  8852. @option{--no-grafts} option makes sure we get the exact same
  8853. environment, with ungrafted packages (@pxref{Security Updates}, for more
  8854. info on grafts).
  8855. To get closer to a container like that used by the build daemon, we can
  8856. remove @file{/bin/sh}:
  8857. @example
  8858. [env]# rm /bin/sh
  8859. @end example
  8860. (Don't worry, this is harmless: this is all happening in the throw-away
  8861. container created by @command{guix environment}.)
  8862. The @command{strace} command is probably not in the search path, but we
  8863. can run:
  8864. @example
  8865. [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
  8866. @end example
  8867. In this way, not only you will have reproduced the environment variables
  8868. the daemon uses, you will also be running the build process in a container
  8869. similar to the one the daemon uses.
  8870. @node Invoking guix edit
  8871. @section Invoking @command{guix edit}
  8872. @cindex @command{guix edit}
  8873. @cindex package definition, editing
  8874. So many packages, so many source files! The @command{guix edit} command
  8875. facilitates the life of users and packagers by pointing their editor at
  8876. the source file containing the definition of the specified packages.
  8877. For instance:
  8878. @example
  8879. guix edit gcc@@4.9 vim
  8880. @end example
  8881. @noindent
  8882. launches the program specified in the @env{VISUAL} or in the
  8883. @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
  8884. and that of Vim.
  8885. If you are using a Guix Git checkout (@pxref{Building from Git}), or
  8886. have created your own packages on @env{GUIX_PACKAGE_PATH}
  8887. (@pxref{Package Modules}), you will be able to edit the package
  8888. recipes. In other cases, you will be able to examine the read-only recipes
  8889. for packages currently in the store.
  8890. Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
  8891. @option{--load-path=@var{directory}} (or in short @option{-L
  8892. @var{directory}}) allows you to add @var{directory} to the front of the
  8893. package module search path and so make your own packages visible.
  8894. @node Invoking guix download
  8895. @section Invoking @command{guix download}
  8896. @cindex @command{guix download}
  8897. @cindex downloading package sources
  8898. When writing a package definition, developers typically need to download
  8899. a source tarball, compute its SHA256 hash, and write that
  8900. hash in the package definition (@pxref{Defining Packages}). The
  8901. @command{guix download} tool helps with this task: it downloads a file
  8902. from the given URI, adds it to the store, and prints both its file name
  8903. in the store and its SHA256 hash.
  8904. The fact that the downloaded file is added to the store saves bandwidth:
  8905. when the developer eventually tries to build the newly defined package
  8906. with @command{guix build}, the source tarball will not have to be
  8907. downloaded again because it is already in the store. It is also a
  8908. convenient way to temporarily stash files, which may be deleted
  8909. eventually (@pxref{Invoking guix gc}).
  8910. The @command{guix download} command supports the same URIs as used in
  8911. package definitions. In particular, it supports @code{mirror://} URIs.
  8912. @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
  8913. Guile bindings for GnuTLS are available in the user's environment; when
  8914. they are not available, an error is raised. @xref{Guile Preparations,
  8915. how to install the GnuTLS bindings for Guile,, gnutls-guile,
  8916. GnuTLS-Guile}, for more information.
  8917. @command{guix download} verifies HTTPS server certificates by loading
  8918. the certificates of X.509 authorities from the directory pointed to by
  8919. the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
  8920. Certificates}), unless @option{--no-check-certificate} is used.
  8921. The following options are available:
  8922. @table @code
  8923. @item --hash=@var{algorithm}
  8924. @itemx -H @var{algorithm}
  8925. Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
  8926. hash}, for more information.
  8927. @item --format=@var{fmt}
  8928. @itemx -f @var{fmt}
  8929. Write the hash in the format specified by @var{fmt}. For more
  8930. information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
  8931. @item --no-check-certificate
  8932. Do not validate the X.509 certificates of HTTPS servers.
  8933. When using this option, you have @emph{absolutely no guarantee} that you
  8934. are communicating with the authentic server responsible for the given
  8935. URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
  8936. @item --output=@var{file}
  8937. @itemx -o @var{file}
  8938. Save the downloaded file to @var{file} instead of adding it to the
  8939. store.
  8940. @end table
  8941. @node Invoking guix hash
  8942. @section Invoking @command{guix hash}
  8943. @cindex @command{guix hash}
  8944. The @command{guix hash} command computes the hash of a file.
  8945. It is primarily a convenience tool for anyone contributing to the
  8946. distribution: it computes the cryptographic hash of a file, which can be
  8947. used in the definition of a package (@pxref{Defining Packages}).
  8948. The general syntax is:
  8949. @example
  8950. guix hash @var{option} @var{file}
  8951. @end example
  8952. When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
  8953. hash of data read from standard input. @command{guix hash} has the
  8954. following options:
  8955. @table @code
  8956. @item --hash=@var{algorithm}
  8957. @itemx -H @var{algorithm}
  8958. Compute a hash using the specified @var{algorithm}, @code{sha256} by
  8959. default.
  8960. @var{algorithm} must the name of a cryptographic hash algorithm
  8961. supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
  8962. @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
  8963. Reference Manual}).
  8964. @item --format=@var{fmt}
  8965. @itemx -f @var{fmt}
  8966. Write the hash in the format specified by @var{fmt}.
  8967. Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
  8968. (@code{hex} and @code{hexadecimal} can be used as well).
  8969. If the @option{--format} option is not specified, @command{guix hash}
  8970. will output the hash in @code{nix-base32}. This representation is used
  8971. in the definitions of packages.
  8972. @item --recursive
  8973. @itemx -r
  8974. Compute the hash on @var{file} recursively.
  8975. In this case, the hash is computed on an archive containing @var{file},
  8976. including its children if it is a directory. Some of the metadata of
  8977. @var{file} is part of the archive; for instance, when @var{file} is a
  8978. regular file, the hash is different depending on whether @var{file} is
  8979. executable or not. Metadata such as time stamps has no impact on the
  8980. hash (@pxref{Invoking guix archive}).
  8981. @c FIXME: Replace xref above with xref to an ``Archive'' section when
  8982. @c it exists.
  8983. @item --exclude-vcs
  8984. @itemx -x
  8985. When combined with @option{--recursive}, exclude version control system
  8986. directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
  8987. @vindex git-fetch
  8988. As an example, here is how you would compute the hash of a Git checkout,
  8989. which is useful when using the @code{git-fetch} method (@pxref{origin
  8990. Reference}):
  8991. @example
  8992. $ git clone http://example.org/foo.git
  8993. $ cd foo
  8994. $ guix hash -rx .
  8995. @end example
  8996. @end table
  8997. @node Invoking guix import
  8998. @section Invoking @command{guix import}
  8999. @cindex importing packages
  9000. @cindex package import
  9001. @cindex package conversion
  9002. @cindex Invoking @command{guix import}
  9003. The @command{guix import} command is useful for people who would like to
  9004. add a package to the distribution with as little work as
  9005. possible---a legitimate demand. The command knows of a few
  9006. repositories from which it can ``import'' package metadata. The result
  9007. is a package definition, or a template thereof, in the format we know
  9008. (@pxref{Defining Packages}).
  9009. The general syntax is:
  9010. @example
  9011. guix import @var{importer} @var{options}@dots{}
  9012. @end example
  9013. @var{importer} specifies the source from which to import package
  9014. metadata, and @var{options} specifies a package identifier and other
  9015. options specific to @var{importer}.
  9016. Some of the importers rely on the ability to run the @command{gpgv} command.
  9017. For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
  9018. gnupg} if needed.
  9019. Currently, the available ``importers'' are:
  9020. @table @code
  9021. @item gnu
  9022. Import metadata for the given GNU package. This provides a template
  9023. for the latest version of that GNU package, including the hash of its
  9024. source tarball, and its canonical synopsis and description.
  9025. Additional information such as the package dependencies and its
  9026. license needs to be figured out manually.
  9027. For example, the following command returns a package definition for
  9028. GNU@tie{}Hello:
  9029. @example
  9030. guix import gnu hello
  9031. @end example
  9032. Specific command-line options are:
  9033. @table @code
  9034. @item --key-download=@var{policy}
  9035. As for @command{guix refresh}, specify the policy to handle missing
  9036. OpenPGP keys when verifying the package signature. @xref{Invoking guix
  9037. refresh, @option{--key-download}}.
  9038. @end table
  9039. @item pypi
  9040. @cindex pypi
  9041. Import metadata from the @uref{https://pypi.python.org/, Python Package
  9042. Index}. Information is taken from the JSON-formatted description
  9043. available at @code{pypi.python.org} and usually includes all the relevant
  9044. information, including package dependencies. For maximum efficiency, it
  9045. is recommended to install the @command{unzip} utility, so that the
  9046. importer can unzip Python wheels and gather data from them.
  9047. The command below imports metadata for the @code{itsdangerous} Python
  9048. package:
  9049. @example
  9050. guix import pypi itsdangerous
  9051. @end example
  9052. @table @code
  9053. @item --recursive
  9054. @itemx -r
  9055. Traverse the dependency graph of the given upstream package recursively
  9056. and generate package expressions for all those packages that are not yet
  9057. in Guix.
  9058. @end table
  9059. @item gem
  9060. @cindex gem
  9061. Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
  9062. is taken from the JSON-formatted description available at
  9063. @code{rubygems.org} and includes most relevant information, including
  9064. runtime dependencies. There are some caveats, however. The metadata
  9065. doesn't distinguish between synopses and descriptions, so the same string
  9066. is used for both fields. Additionally, the details of non-Ruby
  9067. dependencies required to build native extensions is unavailable and left
  9068. as an exercise to the packager.
  9069. The command below imports metadata for the @code{rails} Ruby package:
  9070. @example
  9071. guix import gem rails
  9072. @end example
  9073. @table @code
  9074. @item --recursive
  9075. @itemx -r
  9076. Traverse the dependency graph of the given upstream package recursively
  9077. and generate package expressions for all those packages that are not yet
  9078. in Guix.
  9079. @end table
  9080. @item cpan
  9081. @cindex CPAN
  9082. Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
  9083. Information is taken from the JSON-formatted metadata provided through
  9084. @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
  9085. relevant information, such as module dependencies. License information
  9086. should be checked closely. If Perl is available in the store, then the
  9087. @code{corelist} utility will be used to filter core modules out of the
  9088. list of dependencies.
  9089. The command command below imports metadata for the Acme::Boolean Perl
  9090. module:
  9091. @example
  9092. guix import cpan Acme::Boolean
  9093. @end example
  9094. @item cran
  9095. @cindex CRAN
  9096. @cindex Bioconductor
  9097. Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
  9098. central repository for the @uref{https://r-project.org, GNU@tie{}R
  9099. statistical and graphical environment}.
  9100. Information is extracted from the @file{DESCRIPTION} file of the package.
  9101. The command command below imports metadata for the Cairo R package:
  9102. @example
  9103. guix import cran Cairo
  9104. @end example
  9105. When @option{--recursive} is added, the importer will traverse the
  9106. dependency graph of the given upstream package recursively and generate
  9107. package expressions for all those packages that are not yet in Guix.
  9108. When @option{--style=specification} is added, the importer will generate
  9109. package definitions whose inputs are package specifications instead of
  9110. references to package variables. This is useful when generated package
  9111. definitions are to be appended to existing user modules, as the list of
  9112. used package modules need not be changed. The default is
  9113. @option{--style=variable}.
  9114. When @option{--archive=bioconductor} is added, metadata is imported from
  9115. @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
  9116. packages for the analysis and comprehension of high-throughput
  9117. genomic data in bioinformatics.
  9118. Information is extracted from the @file{DESCRIPTION} file contained in the
  9119. package archive.
  9120. The command below imports metadata for the GenomicRanges R package:
  9121. @example
  9122. guix import cran --archive=bioconductor GenomicRanges
  9123. @end example
  9124. Finally, you can also import R packages that have not yet been published on
  9125. CRAN or Bioconductor as long as they are in a git repository. Use
  9126. @option{--archive=git} followed by the URL of the git repository:
  9127. @example
  9128. guix import cran --archive=git https://github.com/immunogenomics/harmony
  9129. @end example
  9130. @item texlive
  9131. @cindex TeX Live
  9132. @cindex CTAN
  9133. Import metadata from @uref{https://www.ctan.org/, CTAN}, the
  9134. comprehensive TeX archive network for TeX packages that are part of the
  9135. @uref{https://www.tug.org/texlive/, TeX Live distribution}.
  9136. Information about the package is obtained through the XML API provided
  9137. by CTAN, while the source code is downloaded from the SVN repository of
  9138. the Tex Live project. This is done because the CTAN does not keep
  9139. versioned archives.
  9140. The command command below imports metadata for the @code{fontspec}
  9141. TeX package:
  9142. @example
  9143. guix import texlive fontspec
  9144. @end example
  9145. When @option{--archive=@var{directory}} is added, the source code is
  9146. downloaded not from the @file{latex} sub-directory of the
  9147. @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
  9148. the specified sibling @var{directory} under the same root.
  9149. The command below imports metadata for the @code{ifxetex} package from
  9150. CTAN while fetching the sources from the directory
  9151. @file{texmf/source/generic}:
  9152. @example
  9153. guix import texlive --archive=generic ifxetex
  9154. @end example
  9155. @item json
  9156. @cindex JSON, import
  9157. Import package metadata from a local JSON file. Consider the following
  9158. example package definition in JSON format:
  9159. @example
  9160. @{
  9161. "name": "hello",
  9162. "version": "2.10",
  9163. "source": "mirror://gnu/hello/hello-2.10.tar.gz",
  9164. "build-system": "gnu",
  9165. "home-page": "https://www.gnu.org/software/hello/",
  9166. "synopsis": "Hello, GNU world: An example GNU package",
  9167. "description": "GNU Hello prints a greeting.",
  9168. "license": "GPL-3.0+",
  9169. "native-inputs": ["gettext"]
  9170. @}
  9171. @end example
  9172. The field names are the same as for the @code{<package>} record
  9173. (@xref{Defining Packages}). References to other packages are provided
  9174. as JSON lists of quoted package specification strings such as
  9175. @code{guile} or @code{guile@@2.0}.
  9176. The importer also supports a more explicit source definition using the
  9177. common fields for @code{<origin>} records:
  9178. @example
  9179. @{
  9180. @dots{}
  9181. "source": @{
  9182. "method": "url-fetch",
  9183. "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
  9184. "sha256": @{
  9185. "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
  9186. @}
  9187. @}
  9188. @dots{}
  9189. @}
  9190. @end example
  9191. The command below reads metadata from the JSON file @code{hello.json}
  9192. and outputs a package expression:
  9193. @example
  9194. guix import json hello.json
  9195. @end example
  9196. @item nix
  9197. Import metadata from a local copy of the source of the
  9198. @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
  9199. relies on the @command{nix-instantiate} command of
  9200. @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
  9201. typically written in a mixture of Nix-language and Bash code. This
  9202. command only imports the high-level package structure that is written in
  9203. the Nix language. It normally includes all the basic fields of a
  9204. package definition.
  9205. When importing a GNU package, the synopsis and descriptions are replaced
  9206. by their canonical upstream variant.
  9207. Usually, you will first need to do:
  9208. @example
  9209. export NIX_REMOTE=daemon
  9210. @end example
  9211. @noindent
  9212. so that @command{nix-instantiate} does not try to open the Nix database.
  9213. As an example, the command below imports the package definition of
  9214. LibreOffice (more precisely, it imports the definition of the package
  9215. bound to the @code{libreoffice} top-level attribute):
  9216. @example
  9217. guix import nix ~/path/to/nixpkgs libreoffice
  9218. @end example
  9219. @item hackage
  9220. @cindex hackage
  9221. Import metadata from the Haskell community's central package archive
  9222. @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
  9223. Cabal files and includes all the relevant information, including package
  9224. dependencies.
  9225. Specific command-line options are:
  9226. @table @code
  9227. @item --stdin
  9228. @itemx -s
  9229. Read a Cabal file from standard input.
  9230. @item --no-test-dependencies
  9231. @itemx -t
  9232. Do not include dependencies required only by the test suites.
  9233. @item --cabal-environment=@var{alist}
  9234. @itemx -e @var{alist}
  9235. @var{alist} is a Scheme alist defining the environment in which the
  9236. Cabal conditionals are evaluated. The accepted keys are: @code{os},
  9237. @code{arch}, @code{impl} and a string representing the name of a flag.
  9238. The value associated with a flag has to be either the symbol
  9239. @code{true} or @code{false}. The value associated with other keys
  9240. has to conform to the Cabal file format definition. The default value
  9241. associated with the keys @code{os}, @code{arch} and @code{impl} is
  9242. @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
  9243. @item --recursive
  9244. @itemx -r
  9245. Traverse the dependency graph of the given upstream package recursively
  9246. and generate package expressions for all those packages that are not yet
  9247. in Guix.
  9248. @end table
  9249. The command below imports metadata for the latest version of the
  9250. HTTP Haskell package without including test dependencies and
  9251. specifying the value of the flag @samp{network-uri} as @code{false}:
  9252. @example
  9253. guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
  9254. @end example
  9255. A specific package version may optionally be specified by following the
  9256. package name by an at-sign and a version number as in the following example:
  9257. @example
  9258. guix import hackage mtl@@2.1.3.1
  9259. @end example
  9260. @item stackage
  9261. @cindex stackage
  9262. The @code{stackage} importer is a wrapper around the @code{hackage} one.
  9263. It takes a package name, looks up the package version included in a
  9264. long-term support (LTS) @uref{https://www.stackage.org, Stackage}
  9265. release and uses the @code{hackage} importer to retrieve its metadata.
  9266. Note that it is up to you to select an LTS release compatible with the
  9267. GHC compiler used by Guix.
  9268. Specific command-line options are:
  9269. @table @code
  9270. @item --no-test-dependencies
  9271. @itemx -t
  9272. Do not include dependencies required only by the test suites.
  9273. @item --lts-version=@var{version}
  9274. @itemx -l @var{version}
  9275. @var{version} is the desired LTS release version. If omitted the latest
  9276. release is used.
  9277. @item --recursive
  9278. @itemx -r
  9279. Traverse the dependency graph of the given upstream package recursively
  9280. and generate package expressions for all those packages that are not yet
  9281. in Guix.
  9282. @end table
  9283. The command below imports metadata for the HTTP Haskell package
  9284. included in the LTS Stackage release version 7.18:
  9285. @example
  9286. guix import stackage --lts-version=7.18 HTTP
  9287. @end example
  9288. @item elpa
  9289. @cindex elpa
  9290. Import metadata from an Emacs Lisp Package Archive (ELPA) package
  9291. repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
  9292. Specific command-line options are:
  9293. @table @code
  9294. @item --archive=@var{repo}
  9295. @itemx -a @var{repo}
  9296. @var{repo} identifies the archive repository from which to retrieve the
  9297. information. Currently the supported repositories and their identifiers
  9298. are:
  9299. @itemize -
  9300. @item
  9301. @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
  9302. identifier. This is the default.
  9303. Packages from @code{elpa.gnu.org} are signed with one of the keys
  9304. contained in the GnuPG keyring at
  9305. @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
  9306. @code{emacs} package (@pxref{Package Installation, ELPA package
  9307. signatures,, emacs, The GNU Emacs Manual}).
  9308. @item
  9309. @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
  9310. @code{melpa-stable} identifier.
  9311. @item
  9312. @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
  9313. identifier.
  9314. @end itemize
  9315. @item --recursive
  9316. @itemx -r
  9317. Traverse the dependency graph of the given upstream package recursively
  9318. and generate package expressions for all those packages that are not yet
  9319. in Guix.
  9320. @end table
  9321. @item crate
  9322. @cindex crate
  9323. Import metadata from the crates.io Rust package repository
  9324. @uref{https://crates.io, crates.io}, as in this example:
  9325. @example
  9326. guix import crate blake2-rfc
  9327. @end example
  9328. The crate importer also allows you to specify a version string:
  9329. @example
  9330. guix import crate constant-time-eq@@0.1.0
  9331. @end example
  9332. Additional options include:
  9333. @table @code
  9334. @item --recursive
  9335. @itemx -r
  9336. Traverse the dependency graph of the given upstream package recursively
  9337. and generate package expressions for all those packages that are not yet
  9338. in Guix.
  9339. @end table
  9340. @item opam
  9341. @cindex OPAM
  9342. @cindex OCaml
  9343. Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
  9344. repository used by the OCaml community.
  9345. Additional options include:
  9346. @table @code
  9347. @item --recursive
  9348. @itemx -r
  9349. Traverse the dependency graph of the given upstream package recursively
  9350. and generate package expressions for all those packages that are not yet
  9351. in Guix.
  9352. @item --repo
  9353. Select the given repository (a repository name). Possible values include:
  9354. @itemize
  9355. @item @code{opam}, the default opam repository,
  9356. @item @code{coq} or @code{coq-released}, the stable repository for coq packages,
  9357. @item @code{coq-core-dev}, the repository that contains development versions of coq,
  9358. @item @code{coq-extra-dev}, the repository that contains development versions
  9359. of coq packages.
  9360. @end itemize
  9361. @end table
  9362. @end table
  9363. The structure of the @command{guix import} code is modular. It would be
  9364. useful to have more importers for other package formats, and your help
  9365. is welcome here (@pxref{Contributing}).
  9366. @node Invoking guix refresh
  9367. @section Invoking @command{guix refresh}
  9368. @cindex @command {guix refresh}
  9369. The primary audience of the @command{guix refresh} command is developers
  9370. of the GNU software distribution. By default, it reports any packages
  9371. provided by the distribution that are outdated compared to the latest
  9372. upstream version, like this:
  9373. @example
  9374. $ guix refresh
  9375. gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
  9376. gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
  9377. @end example
  9378. Alternatively, one can specify packages to consider, in which case a
  9379. warning is emitted for packages that lack an updater:
  9380. @example
  9381. $ guix refresh coreutils guile guile-ssh
  9382. gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
  9383. gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
  9384. @end example
  9385. @command{guix refresh} browses the upstream repository of each package and determines
  9386. the highest version number of the releases therein. The command
  9387. knows how to update specific types of packages: GNU packages, ELPA
  9388. packages, etc.---see the documentation for @option{--type} below. There
  9389. are many packages, though, for which it lacks a method to determine
  9390. whether a new upstream release is available. However, the mechanism is
  9391. extensible, so feel free to get in touch with us to add a new method!
  9392. @table @code
  9393. @item --recursive
  9394. Consider the packages specified, and all the packages upon which they depend.
  9395. @example
  9396. $ guix refresh --recursive coreutils
  9397. gnu/packages/acl.scm:35:2: warning: no updater for acl
  9398. gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
  9399. gnu/packages/xml.scm:68:2: warning: no updater for expat
  9400. gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
  9401. @dots{}
  9402. @end example
  9403. @end table
  9404. Sometimes the upstream name differs from the package name used in Guix,
  9405. and @command{guix refresh} needs a little help. Most updaters honor the
  9406. @code{upstream-name} property in package definitions, which can be used
  9407. to that effect:
  9408. @lisp
  9409. (define-public network-manager
  9410. (package
  9411. (name "network-manager")
  9412. ;; @dots{}
  9413. (properties '((upstream-name . "NetworkManager")))))
  9414. @end lisp
  9415. When passed @option{--update}, it modifies distribution source files to
  9416. update the version numbers and source tarball hashes of those package
  9417. recipes (@pxref{Defining Packages}). This is achieved by downloading
  9418. each package's latest source tarball and its associated OpenPGP
  9419. signature, authenticating the downloaded tarball against its signature
  9420. using @command{gpgv}, and finally computing its hash---note that GnuPG must be
  9421. installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
  9422. When the public
  9423. key used to sign the tarball is missing from the user's keyring, an
  9424. attempt is made to automatically retrieve it from a public key server;
  9425. when this is successful, the key is added to the user's keyring; otherwise,
  9426. @command{guix refresh} reports an error.
  9427. The following options are supported:
  9428. @table @code
  9429. @item --expression=@var{expr}
  9430. @itemx -e @var{expr}
  9431. Consider the package @var{expr} evaluates to.
  9432. This is useful to precisely refer to a package, as in this example:
  9433. @example
  9434. guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
  9435. @end example
  9436. This command lists the dependents of the ``final'' libc (essentially all
  9437. the packages).
  9438. @item --update
  9439. @itemx -u
  9440. Update distribution source files (package recipes) in place. This is
  9441. usually run from a checkout of the Guix source tree (@pxref{Running
  9442. Guix Before It Is Installed}):
  9443. @example
  9444. $ ./pre-inst-env guix refresh -s non-core -u
  9445. @end example
  9446. @xref{Defining Packages}, for more information on package definitions.
  9447. @item --select=[@var{subset}]
  9448. @itemx -s @var{subset}
  9449. Select all the packages in @var{subset}, one of @code{core} or
  9450. @code{non-core}.
  9451. The @code{core} subset refers to all the packages at the core of the
  9452. distribution---i.e., packages that are used to build ``everything
  9453. else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
  9454. changing one of these packages in the distribution entails a rebuild of
  9455. all the others. Thus, such updates are an inconvenience to users in
  9456. terms of build time or bandwidth used to achieve the upgrade.
  9457. The @code{non-core} subset refers to the remaining packages. It is
  9458. typically useful in cases where an update of the core packages would be
  9459. inconvenient.
  9460. @item --manifest=@var{file}
  9461. @itemx -m @var{file}
  9462. Select all the packages from the manifest in @var{file}. This is useful to
  9463. check if any packages of the user manifest can be updated.
  9464. @item --type=@var{updater}
  9465. @itemx -t @var{updater}
  9466. Select only packages handled by @var{updater} (may be a comma-separated
  9467. list of updaters). Currently, @var{updater} may be one of:
  9468. @table @code
  9469. @item gnu
  9470. the updater for GNU packages;
  9471. @item savannah
  9472. the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
  9473. @item gnome
  9474. the updater for GNOME packages;
  9475. @item kde
  9476. the updater for KDE packages;
  9477. @item xorg
  9478. the updater for X.org packages;
  9479. @item kernel.org
  9480. the updater for packages hosted on kernel.org;
  9481. @item elpa
  9482. the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
  9483. @item cran
  9484. the updater for @uref{https://cran.r-project.org/, CRAN} packages;
  9485. @item bioconductor
  9486. the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
  9487. @item cpan
  9488. the updater for @uref{https://www.cpan.org/, CPAN} packages;
  9489. @item pypi
  9490. the updater for @uref{https://pypi.python.org, PyPI} packages.
  9491. @item gem
  9492. the updater for @uref{https://rubygems.org, RubyGems} packages.
  9493. @item github
  9494. the updater for @uref{https://github.com, GitHub} packages.
  9495. @item hackage
  9496. the updater for @uref{https://hackage.haskell.org, Hackage} packages.
  9497. @item stackage
  9498. the updater for @uref{https://www.stackage.org, Stackage} packages.
  9499. @item crate
  9500. the updater for @uref{https://crates.io, Crates} packages.
  9501. @item launchpad
  9502. the updater for @uref{https://launchpad.net, Launchpad} packages.
  9503. @end table
  9504. For instance, the following command only checks for updates of Emacs
  9505. packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
  9506. @example
  9507. $ guix refresh --type=elpa,cran
  9508. gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
  9509. gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
  9510. @end example
  9511. @end table
  9512. In addition, @command{guix refresh} can be passed one or more package
  9513. names, as in this example:
  9514. @example
  9515. $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
  9516. @end example
  9517. @noindent
  9518. The command above specifically updates the @code{emacs} and
  9519. @code{idutils} packages. The @option{--select} option would have no
  9520. effect in this case.
  9521. When considering whether to upgrade a package, it is sometimes
  9522. convenient to know which packages would be affected by the upgrade and
  9523. should be checked for compatibility. For this the following option may
  9524. be used when passing @command{guix refresh} one or more package names:
  9525. @table @code
  9526. @item --list-updaters
  9527. @itemx -L
  9528. List available updaters and exit (see @option{--type} above).
  9529. For each updater, display the fraction of packages it covers; at the
  9530. end, display the fraction of packages covered by all these updaters.
  9531. @item --list-dependent
  9532. @itemx -l
  9533. List top-level dependent packages that would need to be rebuilt as a
  9534. result of upgrading one or more packages.
  9535. @xref{Invoking guix graph, the @code{reverse-package} type of
  9536. @command{guix graph}}, for information on how to visualize the list of
  9537. dependents of a package.
  9538. @end table
  9539. Be aware that the @option{--list-dependent} option only
  9540. @emph{approximates} the rebuilds that would be required as a result of
  9541. an upgrade. More rebuilds might be required under some circumstances.
  9542. @example
  9543. $ guix refresh --list-dependent flex
  9544. Building the following 120 packages would ensure 213 dependent packages are rebuilt:
  9545. hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
  9546. @end example
  9547. The command above lists a set of packages that could be built to check
  9548. for compatibility with an upgraded @code{flex} package.
  9549. @table @code
  9550. @item --list-transitive
  9551. List all the packages which one or more packages depend upon.
  9552. @example
  9553. $ guix refresh --list-transitive flex
  9554. flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
  9555. 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{}
  9556. @end example
  9557. @end table
  9558. The command above lists a set of packages which, when changed, would cause
  9559. @code{flex} to be rebuilt.
  9560. The following options can be used to customize GnuPG operation:
  9561. @table @code
  9562. @item --gpg=@var{command}
  9563. Use @var{command} as the GnuPG 2.x command. @var{command} is searched
  9564. for in @code{$PATH}.
  9565. @item --keyring=@var{file}
  9566. Use @var{file} as the keyring for upstream keys. @var{file} must be in the
  9567. @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
  9568. and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
  9569. (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
  9570. information on a tool to manipulate keybox files).
  9571. When this option is omitted, @command{guix refresh} uses
  9572. @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
  9573. signing keys. OpenPGP signatures are checked against keys from this keyring;
  9574. missing keys are downloaded to this keyring as well (see
  9575. @option{--key-download} below).
  9576. You can export keys from your default GPG keyring into a keybox file using
  9577. commands like this one:
  9578. @example
  9579. gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
  9580. @end example
  9581. Likewise, you can fetch keys to a specific keybox file like this:
  9582. @example
  9583. gpg --no-default-keyring --keyring mykeyring.kbx \
  9584. --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
  9585. @end example
  9586. @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
  9587. Privacy Guard}, for more information on GPG's @option{--keyring} option.
  9588. @item --key-download=@var{policy}
  9589. Handle missing OpenPGP keys according to @var{policy}, which may be one
  9590. of:
  9591. @table @code
  9592. @item always
  9593. Always download missing OpenPGP keys from the key server, and add them
  9594. to the user's GnuPG keyring.
  9595. @item never
  9596. Never try to download missing OpenPGP keys. Instead just bail out.
  9597. @item interactive
  9598. When a package signed with an unknown OpenPGP key is encountered, ask
  9599. the user whether to download it or not. This is the default behavior.
  9600. @end table
  9601. @item --key-server=@var{host}
  9602. Use @var{host} as the OpenPGP key server when importing a public key.
  9603. @item --load-path=@var{directory}
  9604. Add @var{directory} to the front of the package module search path
  9605. (@pxref{Package Modules}).
  9606. This allows users to define their own packages and make them visible to
  9607. the command-line tools.
  9608. @end table
  9609. The @code{github} updater uses the
  9610. @uref{https://developer.github.com/v3/, GitHub API} to query for new
  9611. releases. When used repeatedly e.g.@: when refreshing all packages,
  9612. GitHub will eventually refuse to answer any further API requests. By
  9613. default 60 API requests per hour are allowed, and a full refresh on all
  9614. GitHub packages in Guix requires more than this. Authentication with
  9615. GitHub through the use of an API token alleviates these limits. To use
  9616. an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
  9617. token procured from @uref{https://github.com/settings/tokens} or
  9618. otherwise.
  9619. @node Invoking guix lint
  9620. @section Invoking @command{guix lint}
  9621. @cindex @command{guix lint}
  9622. @cindex package, checking for errors
  9623. The @command{guix lint} command is meant to help package developers avoid
  9624. common errors and use a consistent style. It runs a number of checks on
  9625. a given set of packages in order to find common mistakes in their
  9626. definitions. Available @dfn{checkers} include (see
  9627. @option{--list-checkers} for a complete list):
  9628. @table @code
  9629. @item synopsis
  9630. @itemx description
  9631. Validate certain typographical and stylistic rules about package
  9632. descriptions and synopses.
  9633. @item inputs-should-be-native
  9634. Identify inputs that should most likely be native inputs.
  9635. @item source
  9636. @itemx home-page
  9637. @itemx mirror-url
  9638. @itemx github-url
  9639. @itemx source-file-name
  9640. Probe @code{home-page} and @code{source} URLs and report those that are
  9641. invalid. Suggest a @code{mirror://} URL when applicable. If the
  9642. @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
  9643. URL@. Check that the source file name is meaningful, e.g.@: is not just a
  9644. version number or ``git-checkout'', without a declared @code{file-name}
  9645. (@pxref{origin Reference}).
  9646. @item source-unstable-tarball
  9647. Parse the @code{source} URL to determine if a tarball from GitHub is
  9648. autogenerated or if it is a release tarball. Unfortunately GitHub's
  9649. autogenerated tarballs are sometimes regenerated.
  9650. @item derivation
  9651. Check that the derivation of the given packages can be successfully
  9652. computed for all the supported systems (@pxref{Derivations}).
  9653. @item profile-collisions
  9654. Check whether installing the given packages in a profile would lead to
  9655. collisions. Collisions occur when several packages with the same name
  9656. but a different version or a different store file name are propagated.
  9657. @xref{package Reference, @code{propagated-inputs}}, for more information
  9658. on propagated inputs.
  9659. @item archival
  9660. @cindex Software Heritage, source code archive
  9661. @cindex archival of source code, Software Heritage
  9662. Checks whether the package's source code is archived at
  9663. @uref{https://www.softwareheritage.org, Software Heritage}.
  9664. When the source code that is not archived comes from a version-control system
  9665. (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
  9666. ``save'' request so that it eventually archives it. This ensures that the
  9667. source will remain available in the long term, and that Guix can fall back to
  9668. Software Heritage should the source code disappear from its original host.
  9669. The status of recent ``save'' requests can be
  9670. @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
  9671. When source code is a tarball obtained with @code{url-fetch}, simply print a
  9672. message when it is not archived. As of this writing, Software Heritage does
  9673. not allow requests to save arbitrary tarballs; we are working on ways to
  9674. ensure that non-VCS source code is also archived.
  9675. Software Heritage
  9676. @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
  9677. request rate per IP address}. When the limit is reached, @command{guix lint}
  9678. prints a message and the @code{archival} checker stops doing anything until
  9679. that limit has been reset.
  9680. @item cve
  9681. @cindex security vulnerabilities
  9682. @cindex CVE, Common Vulnerabilities and Exposures
  9683. Report known vulnerabilities found in the Common Vulnerabilities and
  9684. Exposures (CVE) databases of the current and past year
  9685. @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
  9686. NIST}.
  9687. To view information about a particular vulnerability, visit pages such as:
  9688. @itemize
  9689. @item
  9690. @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
  9691. @item
  9692. @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
  9693. @end itemize
  9694. @noindent
  9695. where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
  9696. @code{CVE-2015-7554}.
  9697. Package developers can specify in package recipes the
  9698. @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
  9699. name and version of the package when they differ from the name or version
  9700. that Guix uses, as in this example:
  9701. @lisp
  9702. (package
  9703. (name "grub")
  9704. ;; @dots{}
  9705. ;; CPE calls this package "grub2".
  9706. (properties '((cpe-name . "grub2")
  9707. (cpe-version . "2.3"))))
  9708. @end lisp
  9709. @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
  9710. Some entries in the CVE database do not specify which version of a
  9711. package they apply to, and would thus ``stick around'' forever. Package
  9712. developers who found CVE alerts and verified they can be ignored can
  9713. declare them as in this example:
  9714. @lisp
  9715. (package
  9716. (name "t1lib")
  9717. ;; @dots{}
  9718. ;; These CVEs no longer apply and can be safely ignored.
  9719. (properties `((lint-hidden-cve . ("CVE-2011-0433"
  9720. "CVE-2011-1553"
  9721. "CVE-2011-1554"
  9722. "CVE-2011-5244")))))
  9723. @end lisp
  9724. @item formatting
  9725. Warn about obvious source code formatting issues: trailing white space,
  9726. use of tabulations, etc.
  9727. @end table
  9728. The general syntax is:
  9729. @example
  9730. guix lint @var{options} @var{package}@dots{}
  9731. @end example
  9732. If no package is given on the command line, then all packages are checked.
  9733. The @var{options} may be zero or more of the following:
  9734. @table @code
  9735. @item --list-checkers
  9736. @itemx -l
  9737. List and describe all the available checkers that will be run on packages
  9738. and exit.
  9739. @item --checkers
  9740. @itemx -c
  9741. Only enable the checkers specified in a comma-separated list using the
  9742. names returned by @option{--list-checkers}.
  9743. @item --exclude
  9744. @itemx -x
  9745. Only disable the checkers specified in a comma-separated list using the
  9746. names returned by @option{--list-checkers}.
  9747. @item --no-network
  9748. @itemx -n
  9749. Only enable the checkers that do not depend on Internet access.
  9750. @item --load-path=@var{directory}
  9751. @itemx -L @var{directory}
  9752. Add @var{directory} to the front of the package module search path
  9753. (@pxref{Package Modules}).
  9754. This allows users to define their own packages and make them visible to
  9755. the command-line tools.
  9756. @end table
  9757. @node Invoking guix size
  9758. @section Invoking @command{guix size}
  9759. @cindex size
  9760. @cindex package size
  9761. @cindex closure
  9762. @cindex @command{guix size}
  9763. The @command{guix size} command helps package developers profile the
  9764. disk usage of packages. It is easy to overlook the impact of an
  9765. additional dependency added to a package, or the impact of using a
  9766. single output for a package that could easily be split (@pxref{Packages
  9767. with Multiple Outputs}). Such are the typical issues that
  9768. @command{guix size} can highlight.
  9769. The command can be passed one or more package specifications
  9770. such as @code{gcc@@4.8}
  9771. or @code{guile:debug}, or a file name in the store. Consider this
  9772. example:
  9773. @example
  9774. $ guix size coreutils
  9775. store item total self
  9776. /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
  9777. /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
  9778. /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
  9779. /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
  9780. /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
  9781. /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
  9782. /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
  9783. /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
  9784. total: 78.9 MiB
  9785. @end example
  9786. @cindex closure
  9787. The store items listed here constitute the @dfn{transitive closure} of
  9788. Coreutils---i.e., Coreutils and all its dependencies, recursively---as
  9789. would be returned by:
  9790. @example
  9791. $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
  9792. @end example
  9793. Here the output shows three columns next to store items. The first column,
  9794. labeled ``total'', shows the size in mebibytes (MiB) of the closure of
  9795. the store item---that is, its own size plus the size of all its
  9796. dependencies. The next column, labeled ``self'', shows the size of the
  9797. item itself. The last column shows the ratio of the size of the item
  9798. itself to the space occupied by all the items listed here.
  9799. In this example, we see that the closure of Coreutils weighs in at
  9800. 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
  9801. libraries. (That libc and GCC's libraries represent a large fraction of
  9802. the closure is not a problem @i{per se} because they are always available
  9803. on the system anyway.)
  9804. Since the command also accepts store file names, assessing the size of
  9805. a build result is straightforward:
  9806. @example
  9807. guix size $(guix system build config.scm)
  9808. @end example
  9809. When the package(s) passed to @command{guix size} are available in the
  9810. store@footnote{More precisely, @command{guix size} looks for the
  9811. @emph{ungrafted} variant of the given package(s), as returned by
  9812. @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
  9813. for information on grafts.}, @command{guix size} queries the daemon to determine its
  9814. dependencies, and measures its size in the store, similar to @command{du
  9815. -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
  9816. Coreutils}).
  9817. When the given packages are @emph{not} in the store, @command{guix size}
  9818. reports information based on the available substitutes
  9819. (@pxref{Substitutes}). This makes it possible it to profile disk usage of
  9820. store items that are not even on disk, only available remotely.
  9821. You can also specify several package names:
  9822. @example
  9823. $ guix size coreutils grep sed bash
  9824. store item total self
  9825. /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
  9826. /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
  9827. /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
  9828. /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
  9829. @dots{}
  9830. total: 102.3 MiB
  9831. @end example
  9832. @noindent
  9833. In this example we see that the combination of the four packages takes
  9834. 102.3@tie{}MiB in total, which is much less than the sum of each closure
  9835. since they have a lot of dependencies in common.
  9836. When looking at the profile returned by @command{guix size}, you may
  9837. find yourself wondering why a given package shows up in the profile at
  9838. all. To understand it, you can use @command{guix graph --path -t
  9839. references} to display the shortest path between the two packages
  9840. (@pxref{Invoking guix graph}).
  9841. The available options are:
  9842. @table @option
  9843. @item --substitute-urls=@var{urls}
  9844. Use substitute information from @var{urls}.
  9845. @xref{client-substitute-urls, the same option for @code{guix build}}.
  9846. @item --sort=@var{key}
  9847. Sort lines according to @var{key}, one of the following options:
  9848. @table @code
  9849. @item self
  9850. the size of each item (the default);
  9851. @item closure
  9852. the total size of the item's closure.
  9853. @end table
  9854. @item --map-file=@var{file}
  9855. Write a graphical map of disk usage in PNG format to @var{file}.
  9856. For the example above, the map looks like this:
  9857. @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
  9858. produced by @command{guix size}}
  9859. This option requires that
  9860. @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
  9861. installed and visible in Guile's module search path. When that is not
  9862. the case, @command{guix size} fails as it tries to load it.
  9863. @item --system=@var{system}
  9864. @itemx -s @var{system}
  9865. Consider packages for @var{system}---e.g., @code{x86_64-linux}.
  9866. @item --load-path=@var{directory}
  9867. @itemx -L @var{directory}
  9868. Add @var{directory} to the front of the package module search path
  9869. (@pxref{Package Modules}).
  9870. This allows users to define their own packages and make them visible to
  9871. the command-line tools.
  9872. @end table
  9873. @node Invoking guix graph
  9874. @section Invoking @command{guix graph}
  9875. @cindex DAG
  9876. @cindex @command{guix graph}
  9877. @cindex package dependencies
  9878. Packages and their dependencies form a @dfn{graph}, specifically a
  9879. directed acyclic graph (DAG). It can quickly become difficult to have a
  9880. mental model of the package DAG, so the @command{guix graph} command
  9881. provides a visual representation of the DAG@. By default,
  9882. @command{guix graph} emits a DAG representation in the input format of
  9883. @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
  9884. directly to the @command{dot} command of Graphviz. It can also emit an
  9885. HTML page with embedded JavaScript code to display a ``chord diagram''
  9886. in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
  9887. emit Cypher queries to construct a graph in a graph database supporting
  9888. the @uref{https://www.opencypher.org/, openCypher} query language. With
  9889. @option{--path}, it simply displays the shortest path between two
  9890. packages. The general syntax is:
  9891. @example
  9892. guix graph @var{options} @var{package}@dots{}
  9893. @end example
  9894. For example, the following command generates a PDF file representing the
  9895. package DAG for the GNU@tie{}Core Utilities, showing its build-time
  9896. dependencies:
  9897. @example
  9898. guix graph coreutils | dot -Tpdf > dag.pdf
  9899. @end example
  9900. The output looks like this:
  9901. @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
  9902. Nice little graph, no?
  9903. You may find it more pleasant to navigate the graph interactively with
  9904. @command{xdot} (from the @code{xdot} package):
  9905. @example
  9906. guix graph coreutils | xdot -
  9907. @end example
  9908. But there is more than one graph! The one above is concise: it is the
  9909. graph of package objects, omitting implicit inputs such as GCC, libc,
  9910. grep, etc. It is often useful to have such a concise graph, but
  9911. sometimes one may want to see more details. @command{guix graph} supports
  9912. several types of graphs, allowing you to choose the level of detail:
  9913. @table @code
  9914. @item package
  9915. This is the default type used in the example above. It shows the DAG of
  9916. package objects, excluding implicit dependencies. It is concise, but
  9917. filters out many details.
  9918. @item reverse-package
  9919. This shows the @emph{reverse} DAG of packages. For example:
  9920. @example
  9921. guix graph --type=reverse-package ocaml
  9922. @end example
  9923. ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
  9924. you are also interested in cases where OCaml is an implicit dependency, see
  9925. @code{reverse-bag} below).
  9926. Note that for core packages this can yield huge graphs. If all you want
  9927. is to know the number of packages that depend on a given package, use
  9928. @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
  9929. @option{--list-dependent}}).
  9930. @item bag-emerged
  9931. This is the package DAG, @emph{including} implicit inputs.
  9932. For instance, the following command:
  9933. @example
  9934. guix graph --type=bag-emerged coreutils
  9935. @end example
  9936. ...@: yields this bigger graph:
  9937. @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
  9938. At the bottom of the graph, we see all the implicit inputs of
  9939. @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
  9940. Now, note that the dependencies of these implicit inputs---that is, the
  9941. @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
  9942. here, for conciseness.
  9943. @item bag
  9944. Similar to @code{bag-emerged}, but this time including all the bootstrap
  9945. dependencies.
  9946. @item bag-with-origins
  9947. Similar to @code{bag}, but also showing origins and their dependencies.
  9948. @item reverse-bag
  9949. This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
  9950. it also takes implicit dependencies into account. For example:
  9951. @example
  9952. guix graph -t reverse-bag dune
  9953. @end example
  9954. @noindent
  9955. ...@: yields the graph of all packages that depend on Dune, directly or
  9956. indirectly. Since Dune is an @emph{implicit} dependency of many packages
  9957. @i{via} @code{dune-build-system}, this shows a large number of packages,
  9958. whereas @code{reverse-package} would show very few if any.
  9959. @item derivation
  9960. This is the most detailed representation: It shows the DAG of
  9961. derivations (@pxref{Derivations}) and plain store items. Compared to
  9962. the above representation, many additional nodes are visible, including
  9963. build scripts, patches, Guile modules, etc.
  9964. For this type of graph, it is also possible to pass a @file{.drv} file
  9965. name instead of a package name, as in:
  9966. @example
  9967. guix graph -t derivation `guix system build -d my-config.scm`
  9968. @end example
  9969. @item module
  9970. This is the graph of @dfn{package modules} (@pxref{Package Modules}).
  9971. For example, the following command shows the graph for the package
  9972. module that defines the @code{guile} package:
  9973. @example
  9974. guix graph -t module guile | xdot -
  9975. @end example
  9976. @end table
  9977. All the types above correspond to @emph{build-time dependencies}. The
  9978. following graph type represents the @emph{run-time dependencies}:
  9979. @table @code
  9980. @item references
  9981. This is the graph of @dfn{references} of a package output, as returned
  9982. by @command{guix gc --references} (@pxref{Invoking guix gc}).
  9983. If the given package output is not available in the store, @command{guix
  9984. graph} attempts to obtain dependency information from substitutes.
  9985. Here you can also pass a store file name instead of a package name. For
  9986. example, the command below produces the reference graph of your profile
  9987. (which can be big!):
  9988. @example
  9989. guix graph -t references `readlink -f ~/.guix-profile`
  9990. @end example
  9991. @item referrers
  9992. This is the graph of the @dfn{referrers} of a store item, as returned by
  9993. @command{guix gc --referrers} (@pxref{Invoking guix gc}).
  9994. This relies exclusively on local information from your store. For
  9995. instance, let us suppose that the current Inkscape is available in 10
  9996. profiles on your machine; @command{guix graph -t referrers inkscape}
  9997. will show a graph rooted at Inkscape and with those 10 profiles linked
  9998. to it.
  9999. It can help determine what is preventing a store item from being garbage
  10000. collected.
  10001. @end table
  10002. @cindex shortest path, between packages
  10003. Often, the graph of the package you are interested in does not fit on
  10004. your screen, and anyway all you want to know is @emph{why} that package
  10005. actually depends on some seemingly unrelated package. The
  10006. @option{--path} option instructs @command{guix graph} to display the
  10007. shortest path between two packages (or derivations, or store items,
  10008. etc.):
  10009. @example
  10010. $ guix graph --path emacs libunistring
  10011. emacs@@26.3
  10012. mailutils@@3.9
  10013. libunistring@@0.9.10
  10014. $ guix graph --path -t derivation emacs libunistring
  10015. /gnu/store/@dots{}-emacs-26.3.drv
  10016. /gnu/store/@dots{}-mailutils-3.9.drv
  10017. /gnu/store/@dots{}-libunistring-0.9.10.drv
  10018. $ guix graph --path -t references emacs libunistring
  10019. /gnu/store/@dots{}-emacs-26.3
  10020. /gnu/store/@dots{}-libidn2-2.2.0
  10021. /gnu/store/@dots{}-libunistring-0.9.10
  10022. @end example
  10023. The available options are the following:
  10024. @table @option
  10025. @item --type=@var{type}
  10026. @itemx -t @var{type}
  10027. Produce a graph output of @var{type}, where @var{type} must be one of
  10028. the values listed above.
  10029. @item --list-types
  10030. List the supported graph types.
  10031. @item --backend=@var{backend}
  10032. @itemx -b @var{backend}
  10033. Produce a graph using the selected @var{backend}.
  10034. @item --list-backends
  10035. List the supported graph backends.
  10036. Currently, the available backends are Graphviz and d3.js.
  10037. @item --path
  10038. Display the shortest path between two nodes of the type specified by
  10039. @option{--type}. The example below shows the shortest path between
  10040. @code{libreoffice} and @code{llvm} according to the references of
  10041. @code{libreoffice}:
  10042. @example
  10043. $ guix graph --path -t references libreoffice llvm
  10044. /gnu/store/@dots{}-libreoffice-6.4.2.2
  10045. /gnu/store/@dots{}-libepoxy-1.5.4
  10046. /gnu/store/@dots{}-mesa-19.3.4
  10047. /gnu/store/@dots{}-llvm-9.0.1
  10048. @end example
  10049. @item --expression=@var{expr}
  10050. @itemx -e @var{expr}
  10051. Consider the package @var{expr} evaluates to.
  10052. This is useful to precisely refer to a package, as in this example:
  10053. @example
  10054. guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
  10055. @end example
  10056. @item --system=@var{system}
  10057. @itemx -s @var{system}
  10058. Display the graph for @var{system}---e.g., @code{i686-linux}.
  10059. The package dependency graph is largely architecture-independent, but there
  10060. are some architecture-dependent bits that this option allows you to visualize.
  10061. @item --load-path=@var{directory}
  10062. @itemx -L @var{directory}
  10063. Add @var{directory} to the front of the package module search path
  10064. (@pxref{Package Modules}).
  10065. This allows users to define their own packages and make them visible to
  10066. the command-line tools.
  10067. @end table
  10068. On top of that, @command{guix graph} supports all the usual package
  10069. transformation options (@pxref{Package Transformation Options}). This
  10070. makes it easy to view the effect of a graph-rewriting transformation
  10071. such as @option{--with-input}. For example, the command below outputs
  10072. the graph of @code{git} once @code{openssl} has been replaced by
  10073. @code{libressl} everywhere in the graph:
  10074. @example
  10075. guix graph git --with-input=openssl=libressl
  10076. @end example
  10077. So many possibilities, so much fun!
  10078. @node Invoking guix publish
  10079. @section Invoking @command{guix publish}
  10080. @cindex @command{guix publish}
  10081. The purpose of @command{guix publish} is to enable users to easily share
  10082. their store with others, who can then use it as a substitute server
  10083. (@pxref{Substitutes}).
  10084. When @command{guix publish} runs, it spawns an HTTP server which allows
  10085. anyone with network access to obtain substitutes from it. This means
  10086. that any machine running Guix can also act as if it were a build farm,
  10087. since the HTTP interface is compatible with Cuirass, the software behind
  10088. the @code{@value{SUBSTITUTE-SERVER}} build farm.
  10089. For security, each substitute is signed, allowing recipients to check
  10090. their authenticity and integrity (@pxref{Substitutes}). Because
  10091. @command{guix publish} uses the signing key of the system, which is only
  10092. readable by the system administrator, it must be started as root; the
  10093. @option{--user} option makes it drop root privileges early on.
  10094. The signing key pair must be generated before @command{guix publish} is
  10095. launched, using @command{guix archive --generate-key} (@pxref{Invoking
  10096. guix archive}).
  10097. When the @option{--advertise} option is passed, the server advertises
  10098. its availability on the local network using multicast DNS (mDNS) and DNS
  10099. service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
  10100. guile-avahi, Using Avahi in Guile Scheme Programs}).
  10101. The general syntax is:
  10102. @example
  10103. guix publish @var{options}@dots{}
  10104. @end example
  10105. Running @command{guix publish} without any additional arguments will
  10106. spawn an HTTP server on port 8080:
  10107. @example
  10108. guix publish
  10109. @end example
  10110. Once a publishing server has been authorized, the daemon may download
  10111. substitutes from it. @xref{Getting Substitutes from Other Servers}.
  10112. By default, @command{guix publish} compresses archives on the fly as it
  10113. serves them. This ``on-the-fly'' mode is convenient in that it requires
  10114. no setup and is immediately available. However, when serving lots of
  10115. clients, we recommend using the @option{--cache} option, which enables
  10116. caching of the archives before they are sent to clients---see below for
  10117. details. The @command{guix weather} command provides a handy way to
  10118. check what a server provides (@pxref{Invoking guix weather}).
  10119. As a bonus, @command{guix publish} also serves as a content-addressed
  10120. mirror for source files referenced in @code{origin} records
  10121. (@pxref{origin Reference}). For instance, assuming @command{guix
  10122. publish} is running on @code{example.org}, the following URL returns the
  10123. raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
  10124. (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
  10125. @example
  10126. http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
  10127. @end example
  10128. Obviously, these URLs only work for files that are in the store; in
  10129. other cases, they return 404 (``Not Found'').
  10130. @cindex build logs, publication
  10131. Build logs are available from @code{/log} URLs like:
  10132. @example
  10133. http://example.org/log/gwspk@dots{}-guile-2.2.3
  10134. @end example
  10135. @noindent
  10136. When @command{guix-daemon} is configured to save compressed build logs,
  10137. as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
  10138. URLs return the compressed log as-is, with an appropriate
  10139. @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
  10140. running @command{guix-daemon} with @option{--log-compression=gzip} since
  10141. Web browsers can automatically decompress it, which is not the case with
  10142. Bzip2 compression.
  10143. The following options are available:
  10144. @table @code
  10145. @item --port=@var{port}
  10146. @itemx -p @var{port}
  10147. Listen for HTTP requests on @var{port}.
  10148. @item --listen=@var{host}
  10149. Listen on the network interface for @var{host}. The default is to
  10150. accept connections from any interface.
  10151. @item --user=@var{user}
  10152. @itemx -u @var{user}
  10153. Change privileges to @var{user} as soon as possible---i.e., once the
  10154. server socket is open and the signing key has been read.
  10155. @item --compression[=@var{method}[:@var{level}]]
  10156. @itemx -C [@var{method}[:@var{level}]]
  10157. Compress data using the given @var{method} and @var{level}. @var{method} is
  10158. one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
  10159. omitted, @code{gzip} is used.
  10160. When @var{level} is zero, disable compression. The range 1 to 9 corresponds
  10161. to different compression levels: 1 is the fastest, and 9 is the best
  10162. (CPU-intensive). The default is 3.
  10163. Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
  10164. small increase in CPU usage; see
  10165. @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
  10166. Web page}. However, @code{lzip} achieves low decompression throughput
  10167. (on the order of 50@tie{}MiB/s on modern hardware), which can be a
  10168. bottleneck for someone who downloads over a fast network connection.
  10169. The compression ratio of @code{zstd} is between that of @code{lzip} and
  10170. that of @code{gzip}; its main advantage is a
  10171. @uref{https://facebook.github.io/zstd/,high decompression speed}.
  10172. Unless @option{--cache} is used, compression occurs on the fly and
  10173. the compressed streams are not
  10174. cached. Thus, to reduce load on the machine that runs @command{guix
  10175. publish}, it may be a good idea to choose a low compression level, to
  10176. run @command{guix publish} behind a caching proxy, or to use
  10177. @option{--cache}. Using @option{--cache} has the advantage that it
  10178. allows @command{guix publish} to add @code{Content-Length} HTTP header
  10179. to its responses.
  10180. This option can be repeated, in which case every substitute gets compressed
  10181. using all the selected methods, and all of them are advertised. This is
  10182. useful when users may not support all the compression methods: they can select
  10183. the one they support.
  10184. @item --cache=@var{directory}
  10185. @itemx -c @var{directory}
  10186. Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
  10187. and only serve archives that are in cache.
  10188. When this option is omitted, archives and meta-data are created
  10189. on-the-fly. This can reduce the available bandwidth, especially when
  10190. compression is enabled, since this may become CPU-bound. Another
  10191. drawback of the default mode is that the length of archives is not known
  10192. in advance, so @command{guix publish} does not add a
  10193. @code{Content-Length} HTTP header to its responses, which in turn
  10194. prevents clients from knowing the amount of data being downloaded.
  10195. Conversely, when @option{--cache} is used, the first request for a store
  10196. item (@i{via} a @code{.narinfo} URL) triggers a
  10197. background process to @dfn{bake} the archive---computing its
  10198. @code{.narinfo} and compressing the archive, if needed. Once the
  10199. archive is cached in @var{directory}, subsequent requests succeed and
  10200. are served directly from the cache, which guarantees that clients get
  10201. the best possible bandwidth.
  10202. That first @code{.narinfo} request nonetheless returns 200, provided the
  10203. requested store item is ``small enough'', below the cache bypass
  10204. threshold---see @option{--cache-bypass-threshold} below. That way,
  10205. clients do not have to wait until the archive is baked. For larger
  10206. store items, the first @code{.narinfo} request returns 404, meaning that
  10207. clients have to wait until the archive is baked.
  10208. The ``baking'' process is performed by worker threads. By default, one
  10209. thread per CPU core is created, but this can be customized. See
  10210. @option{--workers} below.
  10211. When @option{--ttl} is used, cached entries are automatically deleted
  10212. when they have expired.
  10213. @item --workers=@var{N}
  10214. When @option{--cache} is used, request the allocation of @var{N} worker
  10215. threads to ``bake'' archives.
  10216. @item --ttl=@var{ttl}
  10217. Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
  10218. (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
  10219. days, @code{1m} means 1 month, and so on.
  10220. This allows the user's Guix to keep substitute information in cache for
  10221. @var{ttl}. However, note that @code{guix publish} does not itself
  10222. guarantee that the store items it provides will indeed remain available
  10223. for as long as @var{ttl}.
  10224. Additionally, when @option{--cache} is used, cached entries that have
  10225. not been accessed for @var{ttl} and that no longer have a corresponding
  10226. item in the store, may be deleted.
  10227. @item --cache-bypass-threshold=@var{size}
  10228. When used in conjunction with @option{--cache}, store items smaller than
  10229. @var{size} are immediately available, even when they are not yet in
  10230. cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
  10231. for megabytes and so on. The default is @code{10M}.
  10232. ``Cache bypass'' allows you to reduce the publication delay for clients
  10233. at the expense of possibly additional I/O and CPU use on the server
  10234. side: depending on the client access patterns, those store items can end
  10235. up being baked several times until a copy is available in cache.
  10236. Increasing the threshold may be useful for sites that have few users, or
  10237. to guarantee that users get substitutes even for store items that are
  10238. not popular.
  10239. @item --nar-path=@var{path}
  10240. Use @var{path} as the prefix for the URLs of ``nar'' files
  10241. (@pxref{Invoking guix archive, normalized archives}).
  10242. By default, nars are served at a URL such as
  10243. @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
  10244. change the @code{/nar} part to @var{path}.
  10245. @item --public-key=@var{file}
  10246. @itemx --private-key=@var{file}
  10247. Use the specific @var{file}s as the public/private key pair used to sign
  10248. the store items being published.
  10249. The files must correspond to the same key pair (the private key is used
  10250. for signing and the public key is merely advertised in the signature
  10251. metadata). They must contain keys in the canonical s-expression format
  10252. as produced by @command{guix archive --generate-key} (@pxref{Invoking
  10253. guix archive}). By default, @file{/etc/guix/signing-key.pub} and
  10254. @file{/etc/guix/signing-key.sec} are used.
  10255. @item --repl[=@var{port}]
  10256. @itemx -r [@var{port}]
  10257. Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
  10258. Reference Manual}) on @var{port} (37146 by default). This is used
  10259. primarily for debugging a running @command{guix publish} server.
  10260. @end table
  10261. Enabling @command{guix publish} on Guix System is a one-liner: just
  10262. instantiate a @code{guix-publish-service-type} service in the @code{services} field
  10263. of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
  10264. @code{guix-publish-service-type}}).
  10265. If you are instead running Guix on a ``foreign distro'', follow these
  10266. instructions:
  10267. @itemize
  10268. @item
  10269. If your host distro uses the systemd init system:
  10270. @example
  10271. # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
  10272. /etc/systemd/system/
  10273. # systemctl start guix-publish && systemctl enable guix-publish
  10274. @end example
  10275. @item
  10276. If your host distro uses the Upstart init system:
  10277. @example
  10278. # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
  10279. # start guix-publish
  10280. @end example
  10281. @item
  10282. Otherwise, proceed similarly with your distro's init system.
  10283. @end itemize
  10284. @node Invoking guix challenge
  10285. @section Invoking @command{guix challenge}
  10286. @cindex reproducible builds
  10287. @cindex verifiable builds
  10288. @cindex @command{guix challenge}
  10289. @cindex challenge
  10290. Do the binaries provided by this server really correspond to the source
  10291. code it claims to build? Is a package build process deterministic?
  10292. These are the questions the @command{guix challenge} command attempts to
  10293. answer.
  10294. The former is obviously an important question: Before using a substitute
  10295. server (@pxref{Substitutes}), one had better @emph{verify} that it
  10296. provides the right binaries, and thus @emph{challenge} it. The latter
  10297. is what enables the former: If package builds are deterministic, then
  10298. independent builds of the package should yield the exact same result,
  10299. bit for bit; if a server provides a binary different from the one
  10300. obtained locally, it may be either corrupt or malicious.
  10301. We know that the hash that shows up in @file{/gnu/store} file names is
  10302. the hash of all the inputs of the process that built the file or
  10303. directory---compilers, libraries, build scripts,
  10304. etc. (@pxref{Introduction}). Assuming deterministic build processes,
  10305. one store file name should map to exactly one build output.
  10306. @command{guix challenge} checks whether there is, indeed, a single
  10307. mapping by comparing the build outputs of several independent builds of
  10308. any given store item.
  10309. The command output looks like this:
  10310. @smallexample
  10311. $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
  10312. updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
  10313. updating list of substitutes from 'https://guix.example.org'... 100.0%
  10314. /gnu/store/@dots{}-openssl-1.0.2d contents differ:
  10315. local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
  10316. https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
  10317. https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
  10318. differing files:
  10319. /lib/libcrypto.so.1.1
  10320. /lib/libssl.so.1.1
  10321. /gnu/store/@dots{}-git-2.5.0 contents differ:
  10322. local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
  10323. https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
  10324. https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
  10325. differing file:
  10326. /libexec/git-core/git-fsck
  10327. /gnu/store/@dots{}-pius-2.1.1 contents differ:
  10328. local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
  10329. https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
  10330. https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
  10331. differing file:
  10332. /share/man/man1/pius.1.gz
  10333. @dots{}
  10334. 6,406 store items were analyzed:
  10335. - 4,749 (74.1%) were identical
  10336. - 525 (8.2%) differed
  10337. - 1,132 (17.7%) were inconclusive
  10338. @end smallexample
  10339. @noindent
  10340. In this example, @command{guix challenge} first scans the store to
  10341. determine the set of locally-built derivations---as opposed to store
  10342. items that were downloaded from a substitute server---and then queries
  10343. all the substitute servers. It then reports those store items for which
  10344. the servers obtained a result different from the local build.
  10345. @cindex non-determinism, in package builds
  10346. As an example, @code{guix.example.org} always gets a different answer.
  10347. Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
  10348. case of Git. This might indicate that the build process of Git is
  10349. non-deterministic, meaning that its output varies as a function of
  10350. various things that Guix does not fully control, in spite of building
  10351. packages in isolated environments (@pxref{Features}). Most common
  10352. sources of non-determinism include the addition of timestamps in build
  10353. results, the inclusion of random numbers, and directory listings sorted
  10354. by inode number. See @uref{https://reproducible-builds.org/docs/}, for
  10355. more information.
  10356. To find out what is wrong with this Git binary, the easiest approach is
  10357. to run:
  10358. @example
  10359. guix challenge git \
  10360. --diff=diffoscope \
  10361. --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
  10362. @end example
  10363. This automatically invokes @command{diffoscope}, which displays detailed
  10364. information about files that differ.
  10365. Alternatively, we can do something along these lines (@pxref{Invoking guix
  10366. archive}):
  10367. @example
  10368. $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
  10369. | lzip -d | guix archive -x /tmp/git
  10370. $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
  10371. @end example
  10372. This command shows the difference between the files resulting from the
  10373. local build, and the files resulting from the build on
  10374. @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
  10375. diffutils, Comparing and Merging Files}). The @command{diff} command
  10376. works great for text files. When binary files differ, a better option
  10377. is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
  10378. visualize differences for all kinds of files.
  10379. Once you have done that work, you can tell whether the differences are due
  10380. to a non-deterministic build process or to a malicious server. We try
  10381. hard to remove sources of non-determinism in packages to make it easier
  10382. to verify substitutes, but of course, this is a process that
  10383. involves not just Guix, but a large part of the free software community.
  10384. In the meantime, @command{guix challenge} is one tool to help address
  10385. the problem.
  10386. If you are writing packages for Guix, you are encouraged to check
  10387. whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
  10388. same build result as you did with:
  10389. @example
  10390. $ guix challenge @var{package}
  10391. @end example
  10392. @noindent
  10393. where @var{package} is a package specification such as
  10394. @code{guile@@2.0} or @code{glibc:debug}.
  10395. The general syntax is:
  10396. @example
  10397. guix challenge @var{options} [@var{packages}@dots{}]
  10398. @end example
  10399. When a difference is found between the hash of a locally-built item and
  10400. that of a server-provided substitute, or among substitutes provided by
  10401. different servers, the command displays it as in the example above and
  10402. its exit code is 2 (other non-zero exit codes denote other kinds of
  10403. errors).
  10404. The one option that matters is:
  10405. @table @code
  10406. @item --substitute-urls=@var{urls}
  10407. Consider @var{urls} the whitespace-separated list of substitute source
  10408. URLs to compare to.
  10409. @item --diff=@var{mode}
  10410. Upon mismatches, show differences according to @var{mode}, one of:
  10411. @table @asis
  10412. @item @code{simple} (the default)
  10413. Show the list of files that differ.
  10414. @item @code{diffoscope}
  10415. @itemx @var{command}
  10416. Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
  10417. two directories whose contents do not match.
  10418. When @var{command} is an absolute file name, run @var{command} instead
  10419. of Diffoscope.
  10420. @item @code{none}
  10421. Do not show further details about the differences.
  10422. @end table
  10423. Thus, unless @option{--diff=none} is passed, @command{guix challenge}
  10424. downloads the store items from the given substitute servers so that it
  10425. can compare them.
  10426. @item --verbose
  10427. @itemx -v
  10428. Show details about matches (identical contents) in addition to
  10429. information about mismatches.
  10430. @end table
  10431. @node Invoking guix copy
  10432. @section Invoking @command{guix copy}
  10433. @cindex copy, of store items, over SSH
  10434. @cindex SSH, copy of store items
  10435. @cindex sharing store items across machines
  10436. @cindex transferring store items across machines
  10437. The @command{guix copy} command copies items from the store of one
  10438. machine to that of another machine over a secure shell (SSH)
  10439. connection@footnote{This command is available only when Guile-SSH was
  10440. found. @xref{Requirements}, for details.}. For example, the following
  10441. command copies the @code{coreutils} package, the user's profile, and all
  10442. their dependencies over to @var{host}, logged in as @var{user}:
  10443. @example
  10444. guix copy --to=@var{user}@@@var{host} \
  10445. coreutils `readlink -f ~/.guix-profile`
  10446. @end example
  10447. If some of the items to be copied are already present on @var{host},
  10448. they are not actually sent.
  10449. The command below retrieves @code{libreoffice} and @code{gimp} from
  10450. @var{host}, assuming they are available there:
  10451. @example
  10452. guix copy --from=@var{host} libreoffice gimp
  10453. @end example
  10454. The SSH connection is established using the Guile-SSH client, which is
  10455. compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
  10456. @file{~/.ssh/config}, and uses the SSH agent for authentication.
  10457. The key used to sign items that are sent must be accepted by the remote
  10458. machine. Likewise, the key used by the remote machine to sign items you
  10459. are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
  10460. own daemon. @xref{Invoking guix archive}, for more information about
  10461. store item authentication.
  10462. The general syntax is:
  10463. @example
  10464. guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
  10465. @end example
  10466. You must always specify one of the following options:
  10467. @table @code
  10468. @item --to=@var{spec}
  10469. @itemx --from=@var{spec}
  10470. Specify the host to send to or receive from. @var{spec} must be an SSH
  10471. spec such as @code{example.org}, @code{charlie@@example.org}, or
  10472. @code{charlie@@example.org:2222}.
  10473. @end table
  10474. The @var{items} can be either package names, such as @code{gimp}, or
  10475. store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
  10476. When specifying the name of a package to send, it is first built if
  10477. needed, unless @option{--dry-run} was specified. Common build options
  10478. are supported (@pxref{Common Build Options}).
  10479. @node Invoking guix container
  10480. @section Invoking @command{guix container}
  10481. @cindex container
  10482. @cindex @command{guix container}
  10483. @quotation Note
  10484. As of version @value{VERSION}, this tool is experimental. The interface
  10485. is subject to radical change in the future.
  10486. @end quotation
  10487. The purpose of @command{guix container} is to manipulate processes
  10488. running within an isolated environment, commonly known as a
  10489. ``container'', typically created by the @command{guix environment}
  10490. (@pxref{Invoking guix environment}) and @command{guix system container}
  10491. (@pxref{Invoking guix system}) commands.
  10492. The general syntax is:
  10493. @example
  10494. guix container @var{action} @var{options}@dots{}
  10495. @end example
  10496. @var{action} specifies the operation to perform with a container, and
  10497. @var{options} specifies the context-specific arguments for the action.
  10498. The following actions are available:
  10499. @table @code
  10500. @item exec
  10501. Execute a command within the context of a running container.
  10502. The syntax is:
  10503. @example
  10504. guix container exec @var{pid} @var{program} @var{arguments}@dots{}
  10505. @end example
  10506. @var{pid} specifies the process ID of the running container.
  10507. @var{program} specifies an executable file name within the root file
  10508. system of the container. @var{arguments} are the additional options that
  10509. will be passed to @var{program}.
  10510. The following command launches an interactive login shell inside a
  10511. Guix system container, started by @command{guix system container}, and whose
  10512. process ID is 9001:
  10513. @example
  10514. guix container exec 9001 /run/current-system/profile/bin/bash --login
  10515. @end example
  10516. Note that the @var{pid} cannot be the parent process of a container. It
  10517. must be PID 1 of the container or one of its child processes.
  10518. @end table
  10519. @node Invoking guix weather
  10520. @section Invoking @command{guix weather}
  10521. Occasionally you're grumpy because substitutes are lacking and you end
  10522. up building packages by yourself (@pxref{Substitutes}). The
  10523. @command{guix weather} command reports on substitute availability on the
  10524. specified servers so you can have an idea of whether you'll be grumpy
  10525. today. It can sometimes be useful info as a user, but it is primarily
  10526. useful to people running @command{guix publish} (@pxref{Invoking guix
  10527. publish}).
  10528. @cindex statistics, for substitutes
  10529. @cindex availability of substitutes
  10530. @cindex substitute availability
  10531. @cindex weather, substitute availability
  10532. Here's a sample run:
  10533. @example
  10534. $ guix weather --substitute-urls=https://guix.example.org
  10535. computing 5,872 package derivations for x86_64-linux...
  10536. looking for 6,128 store items on https://guix.example.org..
  10537. updating list of substitutes from 'https://guix.example.org'... 100.0%
  10538. https://guix.example.org
  10539. 43.4% substitutes available (2,658 out of 6,128)
  10540. 7,032.5 MiB of nars (compressed)
  10541. 19,824.2 MiB on disk (uncompressed)
  10542. 0.030 seconds per request (182.9 seconds in total)
  10543. 33.5 requests per second
  10544. 9.8% (342 out of 3,470) of the missing items are queued
  10545. 867 queued builds
  10546. x86_64-linux: 518 (59.7%)
  10547. i686-linux: 221 (25.5%)
  10548. aarch64-linux: 128 (14.8%)
  10549. build rate: 23.41 builds per hour
  10550. x86_64-linux: 11.16 builds per hour
  10551. i686-linux: 6.03 builds per hour
  10552. aarch64-linux: 6.41 builds per hour
  10553. @end example
  10554. @cindex continuous integration, statistics
  10555. As you can see, it reports the fraction of all the packages for which
  10556. substitutes are available on the server---regardless of whether
  10557. substitutes are enabled, and regardless of whether this server's signing
  10558. key is authorized. It also reports the size of the compressed archives
  10559. (``nars'') provided by the server, the size the corresponding store
  10560. items occupy in the store (assuming deduplication is turned off), and
  10561. the server's throughput. The second part gives continuous integration
  10562. (CI) statistics, if the server supports it. In addition, using the
  10563. @option{--coverage} option, @command{guix weather} can list ``important''
  10564. package substitutes missing on the server (see below).
  10565. To achieve that, @command{guix weather} queries over HTTP(S) meta-data
  10566. (@dfn{narinfos}) for all the relevant store items. Like @command{guix
  10567. challenge}, it ignores signatures on those substitutes, which is
  10568. innocuous since the command only gathers statistics and cannot install
  10569. those substitutes.
  10570. The general syntax is:
  10571. @example
  10572. guix weather @var{options}@dots{} [@var{packages}@dots{}]
  10573. @end example
  10574. When @var{packages} is omitted, @command{guix weather} checks the availability
  10575. of substitutes for @emph{all} the packages, or for those specified with
  10576. @option{--manifest}; otherwise it only considers the specified packages. It
  10577. is also possible to query specific system types with @option{--system}.
  10578. @command{guix weather} exits with a non-zero code when the fraction of
  10579. available substitutes is below 100%.
  10580. The available options are listed below.
  10581. @table @code
  10582. @item --substitute-urls=@var{urls}
  10583. @var{urls} is the space-separated list of substitute server URLs to
  10584. query. When this option is omitted, the default set of substitute
  10585. servers is queried.
  10586. @item --system=@var{system}
  10587. @itemx -s @var{system}
  10588. Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
  10589. option can be repeated, in which case @command{guix weather} will query
  10590. substitutes for several system types.
  10591. @item --manifest=@var{file}
  10592. Instead of querying substitutes for all the packages, only ask for those
  10593. specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
  10594. with the @code{-m} option of @command{guix package} (@pxref{Invoking
  10595. guix package}).
  10596. This option can be repeated several times, in which case the manifests
  10597. are concatenated.
  10598. @item --coverage[=@var{count}]
  10599. @itemx -c [@var{count}]
  10600. Report on substitute coverage for packages: list packages with at least
  10601. @var{count} dependents (zero by default) for which substitutes are
  10602. unavailable. Dependent packages themselves are not listed: if @var{b} depends
  10603. on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
  10604. @var{b} usually lacks substitutes as well. The result looks like this:
  10605. @example
  10606. $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
  10607. computing 8,983 package derivations for x86_64-linux...
  10608. looking for 9,343 store items on @value{SUBSTITUTE-URL}...
  10609. updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
  10610. @value{SUBSTITUTE-URL}
  10611. 64.7% substitutes available (6,047 out of 9,343)
  10612. @dots{}
  10613. 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
  10614. 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
  10615. 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
  10616. 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
  10617. @dots{}
  10618. @end example
  10619. What this example shows is that @code{kcoreaddons} and presumably the 58
  10620. packages that depend on it have no substitutes at
  10621. @code{@value{SUBSTITUTE-SERVER}}; likewise for @code{qgpgme} and the 46
  10622. packages that depend on it.
  10623. If you are a Guix developer, or if you are taking care of this build farm,
  10624. you'll probably want to have a closer look at these packages: they may simply
  10625. fail to build.
  10626. @item --display-missing
  10627. Display the list of store items for which substitutes are missing.
  10628. @end table
  10629. @node Invoking guix processes
  10630. @section Invoking @command{guix processes}
  10631. The @command{guix processes} command can be useful to developers and system
  10632. administrators, especially on multi-user machines and on build farms: it lists
  10633. the current sessions (connections to the daemon), as well as information about
  10634. the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
  10635. started with @option{--listen} specifying a TCP endpoint, are @emph{not}
  10636. listed.}. Here's an example of the information it returns:
  10637. @example
  10638. $ sudo guix processes
  10639. SessionPID: 19002
  10640. ClientPID: 19090
  10641. ClientCommand: guix environment --ad-hoc python
  10642. SessionPID: 19402
  10643. ClientPID: 19367
  10644. ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
  10645. SessionPID: 19444
  10646. ClientPID: 19419
  10647. ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
  10648. LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
  10649. LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
  10650. LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
  10651. ChildPID: 20495
  10652. ChildCommand: guix offload x86_64-linux 7200 1 28800
  10653. ChildPID: 27733
  10654. ChildCommand: guix offload x86_64-linux 7200 1 28800
  10655. ChildPID: 27793
  10656. ChildCommand: guix offload x86_64-linux 7200 1 28800
  10657. @end example
  10658. In this example we see that @command{guix-daemon} has three clients:
  10659. @command{guix environment}, @command{guix publish}, and the Cuirass continuous
  10660. integration tool; their process identifier (PID) is given by the
  10661. @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
  10662. @command{guix-daemon} sub-process of this particular session.
  10663. The @code{LockHeld} fields show which store items are currently locked
  10664. by this session, which corresponds to store items being built or
  10665. substituted (the @code{LockHeld} field is not displayed when
  10666. @command{guix processes} is not running as root). Last, by looking at
  10667. the @code{ChildPID} and @code{ChildCommand} fields, we understand that
  10668. these three builds are being offloaded (@pxref{Daemon Offload Setup}).
  10669. The output is in Recutils format so we can use the handy @command{recsel}
  10670. command to select sessions of interest (@pxref{Selection Expressions,,,
  10671. recutils, GNU recutils manual}). As an example, the command shows the command
  10672. line and PID of the client that triggered the build of a Perl package:
  10673. @example
  10674. $ sudo guix processes | \
  10675. recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
  10676. ClientPID: 19419
  10677. ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
  10678. @end example
  10679. Additional options are listed below.
  10680. @table @code
  10681. @item --format=@var{format}
  10682. @itemx -f @var{format}
  10683. Produce output in the specified @var{format}, one of:
  10684. @table @code
  10685. @item recutils
  10686. The default option. It outputs a set of Session recutils records
  10687. that include each @code{ChildProcess} as a field.
  10688. @item normalized
  10689. Normalize the output records into record sets (@pxref{Record Sets,,,
  10690. recutils, GNU recutils manual}). Normalizing into record sets allows
  10691. joins across record types. The example below lists the PID of each
  10692. @code{ChildProcess} and the associated PID for @code{Session} that
  10693. spawned the @code{ChildProcess} where the @code{Session} was started
  10694. using @command{guix build}.
  10695. @example
  10696. $ guix processes --format=normalized | \
  10697. recsel \
  10698. -j Session \
  10699. -t ChildProcess \
  10700. -p Session.PID,PID \
  10701. -e 'Session.ClientCommand ~ "guix build"'
  10702. PID: 4435
  10703. Session_PID: 4278
  10704. PID: 4554
  10705. Session_PID: 4278
  10706. PID: 4646
  10707. Session_PID: 4278
  10708. @end example
  10709. @end table
  10710. @end table
  10711. @node System Configuration
  10712. @chapter System Configuration
  10713. @cindex system configuration
  10714. Guix System supports a consistent whole-system configuration
  10715. mechanism. By that we mean that all aspects of the global system
  10716. configuration---such as the available system services, timezone and
  10717. locale settings, user accounts---are declared in a single place. Such
  10718. a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
  10719. One of the advantages of putting all the system configuration under the
  10720. control of Guix is that it supports transactional system upgrades, and
  10721. makes it possible to roll back to a previous system instantiation,
  10722. should something go wrong with the new one (@pxref{Features}). Another
  10723. advantage is that it makes it easy to replicate the exact same configuration
  10724. across different machines, or at different points in time, without
  10725. having to resort to additional administration tools layered on top of
  10726. the own tools of the system.
  10727. @c Yes, we're talking of Puppet, Chef, & co. here. ↑
  10728. This section describes this mechanism. First we focus on the system
  10729. administrator's viewpoint---explaining how the system is configured and
  10730. instantiated. Then we show how this mechanism can be extended, for
  10731. instance to support new system services.
  10732. @menu
  10733. * Using the Configuration System:: Customizing your GNU system.
  10734. * operating-system Reference:: Detail of operating-system declarations.
  10735. * File Systems:: Configuring file system mounts.
  10736. * Mapped Devices:: Block device extra processing.
  10737. * User Accounts:: Specifying user accounts.
  10738. * Keyboard Layout:: How the system interprets key strokes.
  10739. * Locales:: Language and cultural convention settings.
  10740. * Services:: Specifying system services.
  10741. * Setuid Programs:: Programs running with root privileges.
  10742. * X.509 Certificates:: Authenticating HTTPS servers.
  10743. * Name Service Switch:: Configuring libc's name service switch.
  10744. * Initial RAM Disk:: Linux-Libre bootstrapping.
  10745. * Bootloader Configuration:: Configuring the boot loader.
  10746. * Invoking guix system:: Instantiating a system configuration.
  10747. * Invoking guix deploy:: Deploying a system configuration to a remote host.
  10748. * Running Guix in a VM:: How to run Guix System in a virtual machine.
  10749. * Defining Services:: Adding new service definitions.
  10750. @end menu
  10751. @node Using the Configuration System
  10752. @section Using the Configuration System
  10753. The operating system is configured by providing an
  10754. @code{operating-system} declaration in a file that can then be passed to
  10755. the @command{guix system} command (@pxref{Invoking guix system}). A
  10756. simple setup, with the default system services, the default Linux-Libre
  10757. kernel, initial RAM disk, and boot loader looks like this:
  10758. @findex operating-system
  10759. @lisp
  10760. @include os-config-bare-bones.texi
  10761. @end lisp
  10762. This example should be self-describing. Some of the fields defined
  10763. above, such as @code{host-name} and @code{bootloader}, are mandatory.
  10764. Others, such as @code{packages} and @code{services}, can be omitted, in
  10765. which case they get a default value.
  10766. Below we discuss the effect of some of the most important fields
  10767. (@pxref{operating-system Reference}, for details about all the available
  10768. fields), and how to @dfn{instantiate} the operating system using
  10769. @command{guix system}.
  10770. @unnumberedsubsec Bootloader
  10771. @cindex legacy boot, on Intel machines
  10772. @cindex BIOS boot, on Intel machines
  10773. @cindex UEFI boot
  10774. @cindex EFI boot
  10775. The @code{bootloader} field describes the method that will be used to boot
  10776. your system. Machines based on Intel processors can boot in ``legacy'' BIOS
  10777. mode, as in the example above. However, more recent machines rely instead on
  10778. the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
  10779. the @code{bootloader} field should contain something along these lines:
  10780. @lisp
  10781. (bootloader-configuration
  10782. (bootloader grub-efi-bootloader)
  10783. (target "/boot/efi"))
  10784. @end lisp
  10785. @xref{Bootloader Configuration}, for more information on the available
  10786. configuration options.
  10787. @unnumberedsubsec Globally-Visible Packages
  10788. @vindex %base-packages
  10789. The @code{packages} field lists packages that will be globally visible
  10790. on the system, for all user accounts---i.e., in every user's @env{PATH}
  10791. environment variable---in addition to the per-user profiles
  10792. (@pxref{Invoking guix package}). The @code{%base-packages} variable
  10793. provides all the tools one would expect for basic user and administrator
  10794. tasks---including the GNU Core Utilities, the GNU Networking Utilities,
  10795. the GNU Zile lightweight text editor, @command{find}, @command{grep},
  10796. etc. The example above adds GNU@tie{}Screen to those,
  10797. taken from the @code{(gnu packages screen)}
  10798. module (@pxref{Package Modules}). The
  10799. @code{(list package output)} syntax can be used to add a specific output
  10800. of a package:
  10801. @lisp
  10802. (use-modules (gnu packages))
  10803. (use-modules (gnu packages dns))
  10804. (operating-system
  10805. ;; ...
  10806. (packages (cons (list bind "utils")
  10807. %base-packages)))
  10808. @end lisp
  10809. @findex specification->package
  10810. Referring to packages by variable name, like @code{bind} above, has
  10811. the advantage of being unambiguous; it also allows typos and such to be
  10812. diagnosed right away as ``unbound variables''. The downside is that one
  10813. needs to know which module defines which package, and to augment the
  10814. @code{use-package-modules} line accordingly. To avoid that, one can use
  10815. the @code{specification->package} procedure of the @code{(gnu packages)}
  10816. module, which returns the best package for a given name or name and
  10817. version:
  10818. @lisp
  10819. (use-modules (gnu packages))
  10820. (operating-system
  10821. ;; ...
  10822. (packages (append (map specification->package
  10823. '("tcpdump" "htop" "gnupg@@2.0"))
  10824. %base-packages)))
  10825. @end lisp
  10826. @unnumberedsubsec System Services
  10827. @cindex services
  10828. @vindex %base-services
  10829. The @code{services} field lists @dfn{system services} to be made
  10830. available when the system starts (@pxref{Services}).
  10831. The @code{operating-system} declaration above specifies that, in
  10832. addition to the basic services, we want the OpenSSH secure shell
  10833. daemon listening on port 2222 (@pxref{Networking Services,
  10834. @code{openssh-service-type}}). Under the hood,
  10835. @code{openssh-service-type} arranges so that @command{sshd} is started with the
  10836. right command-line options, possibly with supporting configuration files
  10837. generated as needed (@pxref{Defining Services}).
  10838. @cindex customization, of services
  10839. @findex modify-services
  10840. Occasionally, instead of using the base services as is, you will want to
  10841. customize them. To do this, use @code{modify-services} (@pxref{Service
  10842. Reference, @code{modify-services}}) to modify the list.
  10843. For example, suppose you want to modify @code{guix-daemon} and Mingetty
  10844. (the console log-in) in the @code{%base-services} list (@pxref{Base
  10845. Services, @code{%base-services}}). To do that, you can write the
  10846. following in your operating system declaration:
  10847. @lisp
  10848. (define %my-services
  10849. ;; My very own list of services.
  10850. (modify-services %base-services
  10851. (guix-service-type config =>
  10852. (guix-configuration
  10853. (inherit config)
  10854. ;; Fetch substitutes from example.org.
  10855. (substitute-urls
  10856. (list "https://example.org/guix"
  10857. "https://ci.guix.gnu.org"))))
  10858. (mingetty-service-type config =>
  10859. (mingetty-configuration
  10860. (inherit config)
  10861. ;; Automatially log in as "guest".
  10862. (auto-login "guest")))))
  10863. (operating-system
  10864. ;; @dots{}
  10865. (services %my-services))
  10866. @end lisp
  10867. This changes the configuration---i.e., the service parameters---of the
  10868. @code{guix-service-type} instance, and that of all the
  10869. @code{mingetty-service-type} instances in the @code{%base-services} list.
  10870. Observe how this is accomplished: first, we arrange for the original
  10871. configuration to be bound to the identifier @code{config} in the
  10872. @var{body}, and then we write the @var{body} so that it evaluates to the
  10873. desired configuration. In particular, notice how we use @code{inherit}
  10874. to create a new configuration which has the same values as the old
  10875. configuration, but with a few modifications.
  10876. @cindex encrypted disk
  10877. The configuration for a typical ``desktop'' usage, with an encrypted
  10878. root partition, the X11 display
  10879. server, GNOME and Xfce (users can choose which of these desktop
  10880. environments to use at the log-in screen by pressing @kbd{F1}), network
  10881. management, power management, and more, would look like this:
  10882. @lisp
  10883. @include os-config-desktop.texi
  10884. @end lisp
  10885. A graphical system with a choice of lightweight window managers
  10886. instead of full-blown desktop environments would look like this:
  10887. @lisp
  10888. @include os-config-lightweight-desktop.texi
  10889. @end lisp
  10890. This example refers to the @file{/boot/efi} file system by its UUID,
  10891. @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
  10892. as returned by the @command{blkid} command.
  10893. @xref{Desktop Services}, for the exact list of services provided by
  10894. @code{%desktop-services}. @xref{X.509 Certificates}, for background
  10895. information about the @code{nss-certs} package that is used here.
  10896. Again, @code{%desktop-services} is just a list of service objects. If
  10897. you want to remove services from there, you can do so using the
  10898. procedures for list filtering (@pxref{SRFI-1 Filtering and
  10899. Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
  10900. following expression returns a list that contains all the services in
  10901. @code{%desktop-services} minus the Avahi service:
  10902. @lisp
  10903. (remove (lambda (service)
  10904. (eq? (service-kind service) avahi-service-type))
  10905. %desktop-services)
  10906. @end lisp
  10907. @unnumberedsubsec Instantiating the System
  10908. Assuming the @code{operating-system} declaration
  10909. is stored in the @file{my-system-config.scm}
  10910. file, the @command{guix system reconfigure my-system-config.scm} command
  10911. instantiates that configuration, and makes it the default GRUB boot
  10912. entry (@pxref{Invoking guix system}).
  10913. The normal way to change the system configuration is by updating this
  10914. file and re-running @command{guix system reconfigure}. One should never
  10915. have to touch files in @file{/etc} or to run commands that modify the
  10916. system state such as @command{useradd} or @command{grub-install}. In
  10917. fact, you must avoid that since that would not only void your warranty
  10918. but also prevent you from rolling back to previous versions of your
  10919. system, should you ever need to.
  10920. @cindex roll-back, of the operating system
  10921. Speaking of roll-back, each time you run @command{guix system
  10922. reconfigure}, a new @dfn{generation} of the system is created---without
  10923. modifying or deleting previous generations. Old system generations get
  10924. an entry in the bootloader boot menu, allowing you to boot them in case
  10925. something went wrong with the latest generation. Reassuring, no? The
  10926. @command{guix system list-generations} command lists the system
  10927. generations available on disk. It is also possible to roll back the
  10928. system via the commands @command{guix system roll-back} and
  10929. @command{guix system switch-generation}.
  10930. Although the @command{guix system reconfigure} command will not modify
  10931. previous generations, you must take care when the current generation is not
  10932. the latest (e.g., after invoking @command{guix system roll-back}), since
  10933. the operation might overwrite a later generation (@pxref{Invoking guix
  10934. system}).
  10935. @unnumberedsubsec The Programming Interface
  10936. At the Scheme level, the bulk of an @code{operating-system} declaration
  10937. is instantiated with the following monadic procedure (@pxref{The Store
  10938. Monad}):
  10939. @deffn {Monadic Procedure} operating-system-derivation os
  10940. Return a derivation that builds @var{os}, an @code{operating-system}
  10941. object (@pxref{Derivations}).
  10942. The output of the derivation is a single directory that refers to all
  10943. the packages, configuration files, and other supporting files needed to
  10944. instantiate @var{os}.
  10945. @end deffn
  10946. This procedure is provided by the @code{(gnu system)} module. Along
  10947. with @code{(gnu services)} (@pxref{Services}), this module contains the
  10948. guts of Guix System. Make sure to visit it!
  10949. @node operating-system Reference
  10950. @section @code{operating-system} Reference
  10951. This section summarizes all the options available in
  10952. @code{operating-system} declarations (@pxref{Using the Configuration
  10953. System}).
  10954. @deftp {Data Type} operating-system
  10955. This is the data type representing an operating system configuration.
  10956. By that, we mean all the global system configuration, not per-user
  10957. configuration (@pxref{Using the Configuration System}).
  10958. @table @asis
  10959. @item @code{kernel} (default: @code{linux-libre})
  10960. The package object of the operating system kernel to
  10961. use@footnote{Currently only the Linux-libre kernel is fully supported.
  10962. Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
  10963. available when building a virtual machine disk image.}.
  10964. @cindex hurd
  10965. @item @code{hurd} (default: @code{#f})
  10966. The package object of the Hurd to be started by the kernel. When this
  10967. field is set, produce a GNU/Hurd operating system. In that case,
  10968. @code{kernel} must also be set to the @code{gnumach} package---the
  10969. microkernel the Hurd runs on.
  10970. @quotation Warning
  10971. This feature is experimental and only supported for disk images.
  10972. @end quotation
  10973. @item @code{kernel-loadable-modules} (default: '())
  10974. A list of objects (usually packages) to collect loadable kernel modules
  10975. from--e.g. @code{(list ddcci-driver-linux)}.
  10976. @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
  10977. List of strings or gexps representing additional arguments to pass on
  10978. the command-line of the kernel---e.g., @code{("console=ttyS0")}.
  10979. @item @code{bootloader}
  10980. The system bootloader configuration object. @xref{Bootloader Configuration}.
  10981. @item @code{label}
  10982. This is the label (a string) as it appears in the bootloader's menu entry.
  10983. The default label includes the kernel name and version.
  10984. @item @code{keyboard-layout} (default: @code{#f})
  10985. This field specifies the keyboard layout to use in the console. It can be
  10986. either @code{#f}, in which case the default keyboard layout is used (usually
  10987. US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
  10988. for more information.
  10989. This keyboard layout is in effect as soon as the kernel has booted. For
  10990. instance, it is the keyboard layout in effect when you type a passphrase if
  10991. your root file system is on a @code{luks-device-mapping} mapped device
  10992. (@pxref{Mapped Devices}).
  10993. @quotation Note
  10994. This does @emph{not} specify the keyboard layout used by the bootloader, nor
  10995. that used by the graphical display server. @xref{Bootloader Configuration},
  10996. for information on how to specify the bootloader's keyboard layout. @xref{X
  10997. Window}, for information on how to specify the keyboard layout used by the X
  10998. Window System.
  10999. @end quotation
  11000. @item @code{initrd-modules} (default: @code{%base-initrd-modules})
  11001. @cindex initrd
  11002. @cindex initial RAM disk
  11003. The list of Linux kernel modules that need to be available in the
  11004. initial RAM disk. @xref{Initial RAM Disk}.
  11005. @item @code{initrd} (default: @code{base-initrd})
  11006. A procedure that returns an initial RAM disk for the Linux
  11007. kernel. This field is provided to support low-level customization and
  11008. should rarely be needed for casual use. @xref{Initial RAM Disk}.
  11009. @item @code{firmware} (default: @code{%base-firmware})
  11010. @cindex firmware
  11011. List of firmware packages loadable by the operating system kernel.
  11012. The default includes firmware needed for Atheros- and Broadcom-based
  11013. WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
  11014. respectively). @xref{Hardware Considerations}, for more info on
  11015. supported hardware.
  11016. @item @code{host-name}
  11017. The host name.
  11018. @item @code{hosts-file}
  11019. @cindex hosts file
  11020. A file-like object (@pxref{G-Expressions, file-like objects}) for use as
  11021. @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
  11022. Reference Manual}). The default is a file with entries for
  11023. @code{localhost} and @var{host-name}.
  11024. @item @code{mapped-devices} (default: @code{'()})
  11025. A list of mapped devices. @xref{Mapped Devices}.
  11026. @item @code{file-systems}
  11027. A list of file systems. @xref{File Systems}.
  11028. @cindex swap devices
  11029. @cindex swap space
  11030. @item @code{swap-devices} (default: @code{'()})
  11031. A list of UUIDs, file system labels, or strings identifying devices or
  11032. files to be used for ``swap
  11033. space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
  11034. Manual}). Here are some examples:
  11035. @table @code
  11036. @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
  11037. Use the swap partition with the given UUID@. You can learn the UUID of a
  11038. Linux swap partition by running @command{swaplabel @var{device}}, where
  11039. @var{device} is the @file{/dev} file name of that partition.
  11040. @item (list (file-system-label "swap"))
  11041. Use the partition with label @code{swap}. Again, the
  11042. @command{swaplabel} command allows you to view and change the label of a
  11043. Linux swap partition.
  11044. @item (list "/swapfile")
  11045. Use the file @file{/swapfile} as swap space.
  11046. @item (list "/dev/sda3" "/dev/sdb2")
  11047. Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
  11048. We recommend referring to swap devices by UUIDs or labels as shown above
  11049. instead.
  11050. @end table
  11051. It is possible to specify a swap file in a file system on a mapped
  11052. device (under @file{/dev/mapper}), provided that the necessary device
  11053. mapping and file system are also specified. @xref{Mapped Devices} and
  11054. @ref{File Systems}.
  11055. @item @code{users} (default: @code{%base-user-accounts})
  11056. @itemx @code{groups} (default: @code{%base-groups})
  11057. List of user accounts and groups. @xref{User Accounts}.
  11058. If the @code{users} list lacks a user account with UID@tie{}0, a
  11059. ``root'' account with UID@tie{}0 is automatically added.
  11060. @item @code{skeletons} (default: @code{(default-skeletons)})
  11061. A list of target file name/file-like object tuples (@pxref{G-Expressions,
  11062. file-like objects}). These are the skeleton files that will be added to
  11063. the home directory of newly-created user accounts.
  11064. For instance, a valid value may look like this:
  11065. @lisp
  11066. `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
  11067. (".guile" ,(plain-file "guile"
  11068. "(use-modules (ice-9 readline))
  11069. (activate-readline)")))
  11070. @end lisp
  11071. @item @code{issue} (default: @code{%default-issue})
  11072. A string denoting the contents of the @file{/etc/issue} file, which is
  11073. displayed when users log in on a text console.
  11074. @item @code{packages} (default: @code{%base-packages})
  11075. A list of packages to be installed in the global profile, which is accessible
  11076. at @file{/run/current-system/profile}. Each element is either a package
  11077. variable or a package/output tuple. Here's a simple example of both:
  11078. @lisp
  11079. (cons* git ; the default "out" output
  11080. (list git "send-email") ; another output of git
  11081. %base-packages) ; the default set
  11082. @end lisp
  11083. The default set includes core utilities and it is good practice to
  11084. install non-core utilities in user profiles (@pxref{Invoking guix
  11085. package}).
  11086. @item @code{timezone}
  11087. A timezone identifying string---e.g., @code{"Europe/Paris"}.
  11088. You can run the @command{tzselect} command to find out which timezone
  11089. string corresponds to your region. Choosing an invalid timezone name
  11090. causes @command{guix system} to fail.
  11091. @item @code{locale} (default: @code{"en_US.utf8"})
  11092. The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
  11093. Library Reference Manual}). @xref{Locales}, for more information.
  11094. @item @code{locale-definitions} (default: @code{%default-locale-definitions})
  11095. The list of locale definitions to be compiled and that may be used at
  11096. run time. @xref{Locales}.
  11097. @item @code{locale-libcs} (default: @code{(list @var{glibc})})
  11098. The list of GNU@tie{}libc packages whose locale data and tools are used
  11099. to build the locale definitions. @xref{Locales}, for compatibility
  11100. considerations that justify this option.
  11101. @item @code{name-service-switch} (default: @code{%default-nss})
  11102. Configuration of the libc name service switch (NSS)---a
  11103. @code{<name-service-switch>} object. @xref{Name Service Switch}, for
  11104. details.
  11105. @item @code{services} (default: @code{%base-services})
  11106. A list of service objects denoting system services. @xref{Services}.
  11107. @cindex essential services
  11108. @item @code{essential-services} (default: ...)
  11109. The list of ``essential services''---i.e., things like instances of
  11110. @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
  11111. Reference}), which are derived from the operating system definition itself.
  11112. As a user you should @emph{never} need to touch this field.
  11113. @item @code{pam-services} (default: @code{(base-pam-services)})
  11114. @cindex PAM
  11115. @cindex pluggable authentication modules
  11116. Linux @dfn{pluggable authentication module} (PAM) services.
  11117. @c FIXME: Add xref to PAM services section.
  11118. @item @code{setuid-programs} (default: @code{%setuid-programs})
  11119. List of string-valued G-expressions denoting setuid programs.
  11120. @xref{Setuid Programs}.
  11121. @item @code{sudoers-file} (default: @code{%sudoers-specification})
  11122. @cindex sudoers file
  11123. The contents of the @file{/etc/sudoers} file as a file-like object
  11124. (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
  11125. This file specifies which users can use the @command{sudo} command, what
  11126. they are allowed to do, and what privileges they may gain. The default
  11127. is that only @code{root} and members of the @code{wheel} group may use
  11128. @code{sudo}.
  11129. @end table
  11130. @deffn {Scheme Syntax} this-operating-system
  11131. When used in the @emph{lexical scope} of an operating system field definition,
  11132. this identifier resolves to the operating system being defined.
  11133. The example below shows how to refer to the operating system being defined in
  11134. the definition of the @code{label} field:
  11135. @lisp
  11136. (use-modules (gnu) (guix))
  11137. (operating-system
  11138. ;; ...
  11139. (label (package-full-name
  11140. (operating-system-kernel this-operating-system))))
  11141. @end lisp
  11142. It is an error to refer to @code{this-operating-system} outside an operating
  11143. system definition.
  11144. @end deffn
  11145. @end deftp
  11146. @node File Systems
  11147. @section File Systems
  11148. The list of file systems to be mounted is specified in the
  11149. @code{file-systems} field of the operating system declaration
  11150. (@pxref{Using the Configuration System}). Each file system is declared
  11151. using the @code{file-system} form, like this:
  11152. @lisp
  11153. (file-system
  11154. (mount-point "/home")
  11155. (device "/dev/sda3")
  11156. (type "ext4"))
  11157. @end lisp
  11158. As usual, some of the fields are mandatory---those shown in the example
  11159. above---while others can be omitted. These are described below.
  11160. @deftp {Data Type} file-system
  11161. Objects of this type represent file systems to be mounted. They
  11162. contain the following members:
  11163. @table @asis
  11164. @item @code{type}
  11165. This is a string specifying the type of the file system---e.g.,
  11166. @code{"ext4"}.
  11167. @item @code{mount-point}
  11168. This designates the place where the file system is to be mounted.
  11169. @item @code{device}
  11170. This names the ``source'' of the file system. It can be one of three
  11171. things: a file system label, a file system UUID, or the name of a
  11172. @file{/dev} node. Labels and UUIDs offer a way to refer to file
  11173. systems without having to hard-code their actual device
  11174. name@footnote{Note that, while it is tempting to use
  11175. @file{/dev/disk/by-uuid} and similar device names to achieve the same
  11176. result, this is not recommended: These special device nodes are created
  11177. by the udev daemon and may be unavailable at the time the device is
  11178. mounted.}.
  11179. @findex file-system-label
  11180. File system labels are created using the @code{file-system-label}
  11181. procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
  11182. plain strings. Here's an example of a file system referred to by its
  11183. label, as shown by the @command{e2label} command:
  11184. @lisp
  11185. (file-system
  11186. (mount-point "/home")
  11187. (type "ext4")
  11188. (device (file-system-label "my-home")))
  11189. @end lisp
  11190. @findex uuid
  11191. UUIDs are converted from their string representation (as shown by the
  11192. @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
  11193. @code{uuid} form expects 16-byte UUIDs as defined in
  11194. @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
  11195. form of UUID used by the ext2 family of file systems and others, but it
  11196. is different from ``UUIDs'' found in FAT file systems, for instance.},
  11197. like this:
  11198. @lisp
  11199. (file-system
  11200. (mount-point "/home")
  11201. (type "ext4")
  11202. (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
  11203. @end lisp
  11204. When the source of a file system is a mapped device (@pxref{Mapped
  11205. Devices}), its @code{device} field @emph{must} refer to the mapped
  11206. device name---e.g., @file{"/dev/mapper/root-partition"}.
  11207. This is required so that
  11208. the system knows that mounting the file system depends on having the
  11209. corresponding device mapping established.
  11210. @item @code{flags} (default: @code{'()})
  11211. This is a list of symbols denoting mount flags. Recognized flags
  11212. include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
  11213. access to special files), @code{no-suid} (ignore setuid and setgid
  11214. bits), @code{no-atime} (do not update file access times),
  11215. @code{strict-atime} (update file access time), @code{lazy-time} (only
  11216. update time on the in-memory version of the file inode), and
  11217. @code{no-exec} (disallow program execution).
  11218. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
  11219. Manual}, for more information on these flags.
  11220. @item @code{options} (default: @code{#f})
  11221. This is either @code{#f}, or a string denoting mount options passed to
  11222. the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
  11223. Library Reference Manual}, for details and run @command{man 8 mount} for
  11224. options for various file systems. Note that the
  11225. @code{file-system-options->alist} and @code{alist->file-system-options}
  11226. procedures from @code{(gnu system file-systems)} can be used to convert
  11227. file system options given as an association list to the string
  11228. representation, and vice-versa.
  11229. @item @code{mount?} (default: @code{#t})
  11230. This value indicates whether to automatically mount the file system when
  11231. the system is brought up. When set to @code{#f}, the file system gets
  11232. an entry in @file{/etc/fstab} (read by the @command{mount} command) but
  11233. is not automatically mounted.
  11234. @item @code{needed-for-boot?} (default: @code{#f})
  11235. This Boolean value indicates whether the file system is needed when
  11236. booting. If that is true, then the file system is mounted when the
  11237. initial RAM disk (initrd) is loaded. This is always the case, for
  11238. instance, for the root file system.
  11239. @item @code{check?} (default: @code{#t})
  11240. This Boolean indicates whether the file system needs to be checked for
  11241. errors before being mounted.
  11242. @item @code{create-mount-point?} (default: @code{#f})
  11243. When true, the mount point is created if it does not exist yet.
  11244. @item @code{mount-may-fail?} (default: @code{#f})
  11245. When true, this indicates that mounting this file system can fail but
  11246. that should not be considered an error. This is useful in unusual
  11247. cases; an example of this is @code{efivarfs}, a file system that can
  11248. only be mounted on EFI/UEFI systems.
  11249. @item @code{dependencies} (default: @code{'()})
  11250. This is a list of @code{<file-system>} or @code{<mapped-device>} objects
  11251. representing file systems that must be mounted or mapped devices that
  11252. must be opened before (and unmounted or closed after) this one.
  11253. As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
  11254. a dependency of @file{/sys/fs/cgroup/cpu} and
  11255. @file{/sys/fs/cgroup/memory}.
  11256. Another example is a file system that depends on a mapped device, for
  11257. example for an encrypted partition (@pxref{Mapped Devices}).
  11258. @end table
  11259. @end deftp
  11260. @deffn {Scheme Procedure} file-system-label @var{str}
  11261. This procedure returns an opaque file system label from @var{str}, a
  11262. string:
  11263. @lisp
  11264. (file-system-label "home")
  11265. @result{} #<file-system-label "home">
  11266. @end lisp
  11267. File system labels are used to refer to file systems by label rather
  11268. than by device name. See above for examples.
  11269. @end deffn
  11270. The @code{(gnu system file-systems)} exports the following useful
  11271. variables.
  11272. @defvr {Scheme Variable} %base-file-systems
  11273. These are essential file systems that are required on normal systems,
  11274. such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
  11275. below). Operating system declarations should always contain at least
  11276. these.
  11277. @end defvr
  11278. @defvr {Scheme Variable} %pseudo-terminal-file-system
  11279. This is the file system to be mounted as @file{/dev/pts}. It supports
  11280. @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
  11281. functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
  11282. Manual}). Pseudo-terminals are used by terminal emulators such as
  11283. @command{xterm}.
  11284. @end defvr
  11285. @defvr {Scheme Variable} %shared-memory-file-system
  11286. This file system is mounted as @file{/dev/shm} and is used to support
  11287. memory sharing across processes (@pxref{Memory-mapped I/O,
  11288. @code{shm_open},, libc, The GNU C Library Reference Manual}).
  11289. @end defvr
  11290. @defvr {Scheme Variable} %immutable-store
  11291. This file system performs a read-only ``bind mount'' of
  11292. @file{/gnu/store}, making it read-only for all the users including
  11293. @code{root}. This prevents against accidental modification by software
  11294. running as @code{root} or by system administrators.
  11295. The daemon itself is still able to write to the store: it remounts it
  11296. read-write in its own ``name space.''
  11297. @end defvr
  11298. @defvr {Scheme Variable} %binary-format-file-system
  11299. The @code{binfmt_misc} file system, which allows handling of arbitrary
  11300. executable file types to be delegated to user space. This requires the
  11301. @code{binfmt.ko} kernel module to be loaded.
  11302. @end defvr
  11303. @defvr {Scheme Variable} %fuse-control-file-system
  11304. The @code{fusectl} file system, which allows unprivileged users to mount
  11305. and unmount user-space FUSE file systems. This requires the
  11306. @code{fuse.ko} kernel module to be loaded.
  11307. @end defvr
  11308. The @code{(gnu system uuid)} module provides tools to deal with file
  11309. system ``unique identifiers'' (UUIDs).
  11310. @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
  11311. Return an opaque UUID (unique identifier) object of the given @var{type}
  11312. (a symbol) by parsing @var{str} (a string):
  11313. @lisp
  11314. (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
  11315. @result{} #<<uuid> type: dce bv: @dots{}>
  11316. (uuid "1234-ABCD" 'fat)
  11317. @result{} #<<uuid> type: fat bv: @dots{}>
  11318. @end lisp
  11319. @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
  11320. @code{ntfs}, or one of the commonly found synonyms for these.
  11321. UUIDs are another way to unambiguously refer to file systems in
  11322. operating system configuration. See the examples above.
  11323. @end deffn
  11324. @node Btrfs file system
  11325. @subsection Btrfs file system
  11326. The Btrfs has special features, such as subvolumes, that merit being
  11327. explained in more details. The following section attempts to cover
  11328. basic as well as complex uses of a Btrfs file system with the Guix
  11329. System.
  11330. In its simplest usage, a Btrfs file system can be described, for
  11331. example, by:
  11332. @lisp
  11333. (file-system
  11334. (mount-point "/home")
  11335. (type "btrfs")
  11336. (device (file-system-label "my-home")))
  11337. @end lisp
  11338. The example below is more complex, as it makes use of a Btrfs
  11339. subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
  11340. @code{my-btrfs-pool}, and is located on an encrypted device (hence the
  11341. dependency on @code{mapped-devices}):
  11342. @lisp
  11343. (file-system
  11344. (device (file-system-label "my-btrfs-pool"))
  11345. (mount-point "/")
  11346. (type "btrfs")
  11347. (options "subvol=rootfs")
  11348. (dependencies mapped-devices))
  11349. @end lisp
  11350. Some bootloaders, for example GRUB, only mount a Btrfs partition at its
  11351. top level during the early boot, and rely on their configuration to
  11352. refer to the correct subvolume path within that top level. The
  11353. bootloaders operating in this way typically produce their configuration
  11354. on a running system where the Btrfs partitions are already mounted and
  11355. where the subvolume information is readily available. As an example,
  11356. @command{grub-mkconfig}, the configuration generator command shipped
  11357. with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
  11358. path of a subvolume.
  11359. The Guix System produces a bootloader configuration using the operating
  11360. system configuration as its sole input; it is therefore necessary to
  11361. extract the subvolume name on which @file{/gnu/store} lives (if any)
  11362. from that operating system configuration. To better illustrate,
  11363. consider a subvolume named 'rootfs' which contains the root file system
  11364. data. In such situation, the GRUB bootloader would only see the top
  11365. level of the root Btrfs partition, e.g.:
  11366. @example
  11367. / (top level)
  11368. ├── rootfs (subvolume directory)
  11369. ├── gnu (normal directory)
  11370. ├── store (normal directory)
  11371. [...]
  11372. @end example
  11373. Thus, the subvolume name must be prepended to the @file{/gnu/store} path
  11374. of the kernel, initrd binaries and any other files referred to in the
  11375. GRUB configuration that must be found during the early boot.
  11376. The next example shows a nested hierarchy of subvolumes and
  11377. directories:
  11378. @example
  11379. / (top level)
  11380. ├── rootfs (subvolume)
  11381. ├── gnu (normal directory)
  11382. ├── store (subvolume)
  11383. [...]
  11384. @end example
  11385. This scenario would work without mounting the 'store' subvolume.
  11386. Mounting 'rootfs' is sufficient, since the subvolume name matches its
  11387. intended mount point in the file system hierarchy. Alternatively, the
  11388. 'store' subvolume could be referred to by setting the @code{subvol}
  11389. option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
  11390. Finally, a more contrived example of nested subvolumes:
  11391. @example
  11392. / (top level)
  11393. ├── root-snapshots (subvolume)
  11394. ├── root-current (subvolume)
  11395. ├── guix-store (subvolume)
  11396. [...]
  11397. @end example
  11398. Here, the 'guix-store' subvolume doesn't match its intended mount point,
  11399. so it is necessary to mount it. The subvolume must be fully specified,
  11400. by passing its file name to the @code{subvol} option. To illustrate,
  11401. the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
  11402. a file system declaration such as:
  11403. @lisp
  11404. (file-system
  11405. (device (file-system-label "btrfs-pool-1"))
  11406. (mount-point "/gnu/store")
  11407. (type "btrfs")
  11408. (options "subvol=root-snapshots/root-current/guix-store,\
  11409. compress-force=zstd,space_cache=v2"))
  11410. @end lisp
  11411. @node Mapped Devices
  11412. @section Mapped Devices
  11413. @cindex device mapping
  11414. @cindex mapped devices
  11415. The Linux kernel has a notion of @dfn{device mapping}: a block device,
  11416. such as a hard disk partition, can be @dfn{mapped} into another device,
  11417. usually in @code{/dev/mapper/},
  11418. with additional processing over the data that flows through
  11419. it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
  11420. concept of a ``mapped device'' and that of a file system: both boil down
  11421. to @emph{translating} input/output operations made on a file to
  11422. operations on its backing store. Thus, the Hurd implements mapped
  11423. devices, like file systems, using the generic @dfn{translator} mechanism
  11424. (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
  11425. typical example is encryption device mapping: all writes to the mapped
  11426. device are encrypted, and all reads are deciphered, transparently.
  11427. Guix extends this notion by considering any device or set of devices that
  11428. are @dfn{transformed} in some way to create a new device; for instance,
  11429. RAID devices are obtained by @dfn{assembling} several other devices, such
  11430. as hard disks or partitions, into a new one that behaves as one partition.
  11431. Mapped devices are declared using the @code{mapped-device} form,
  11432. defined as follows; for examples, see below.
  11433. @deftp {Data Type} mapped-device
  11434. Objects of this type represent device mappings that will be made when
  11435. the system boots up.
  11436. @table @code
  11437. @item source
  11438. This is either a string specifying the name of the block device to be mapped,
  11439. such as @code{"/dev/sda3"}, or a list of such strings when several devices
  11440. need to be assembled for creating a new one. In case of LVM this is a
  11441. string specifying name of the volume group to be mapped.
  11442. @item target
  11443. This string specifies the name of the resulting mapped device. For
  11444. kernel mappers such as encrypted devices of type @code{luks-device-mapping},
  11445. specifying @code{"my-partition"} leads to the creation of
  11446. the @code{"/dev/mapper/my-partition"} device.
  11447. For RAID devices of type @code{raid-device-mapping}, the full device name
  11448. such as @code{"/dev/md0"} needs to be given.
  11449. LVM logical volumes of type @code{lvm-device-mapping} need to
  11450. be specified as @code{"VGNAME-LVNAME"}.
  11451. @item targets
  11452. This list of strings specifies names of the resulting mapped devices in case
  11453. there are several. The format is identical to @var{target}.
  11454. @item type
  11455. This must be a @code{mapped-device-kind} object, which specifies how
  11456. @var{source} is mapped to @var{target}.
  11457. @end table
  11458. @end deftp
  11459. @defvr {Scheme Variable} luks-device-mapping
  11460. This defines LUKS block device encryption using the @command{cryptsetup}
  11461. command from the package with the same name. It relies on the
  11462. @code{dm-crypt} Linux kernel module.
  11463. @end defvr
  11464. @defvr {Scheme Variable} raid-device-mapping
  11465. This defines a RAID device, which is assembled using the @code{mdadm}
  11466. command from the package with the same name. It requires a Linux kernel
  11467. module for the appropriate RAID level to be loaded, such as @code{raid456}
  11468. for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
  11469. @end defvr
  11470. @cindex LVM, logical volume manager
  11471. @defvr {Scheme Variable} lvm-device-mapping
  11472. This defines one or more logical volumes for the Linux
  11473. @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
  11474. The volume group is activated by the @command{vgchange} command from the
  11475. @code{lvm2} package.
  11476. @end defvr
  11477. @cindex disk encryption
  11478. @cindex LUKS
  11479. The following example specifies a mapping from @file{/dev/sda3} to
  11480. @file{/dev/mapper/home} using LUKS---the
  11481. @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
  11482. standard mechanism for disk encryption.
  11483. The @file{/dev/mapper/home}
  11484. device can then be used as the @code{device} of a @code{file-system}
  11485. declaration (@pxref{File Systems}).
  11486. @lisp
  11487. (mapped-device
  11488. (source "/dev/sda3")
  11489. (target "home")
  11490. (type luks-device-mapping))
  11491. @end lisp
  11492. Alternatively, to become independent of device numbering, one may obtain
  11493. the LUKS UUID (@dfn{unique identifier}) of the source device by a
  11494. command like:
  11495. @example
  11496. cryptsetup luksUUID /dev/sda3
  11497. @end example
  11498. and use it as follows:
  11499. @lisp
  11500. (mapped-device
  11501. (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
  11502. (target "home")
  11503. (type luks-device-mapping))
  11504. @end lisp
  11505. @cindex swap encryption
  11506. It is also desirable to encrypt swap space, since swap space may contain
  11507. sensitive data. One way to accomplish that is to use a swap file in a
  11508. file system on a device mapped via LUKS encryption. In this way, the
  11509. swap file is encrypted because the entire device is encrypted.
  11510. @xref{Preparing for Installation,,Disk Partitioning}, for an example.
  11511. A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
  11512. may be declared as follows:
  11513. @lisp
  11514. (mapped-device
  11515. (source (list "/dev/sda1" "/dev/sdb1"))
  11516. (target "/dev/md0")
  11517. (type raid-device-mapping))
  11518. @end lisp
  11519. The @file{/dev/md0} device can then be used as the @code{device} of a
  11520. @code{file-system} declaration (@pxref{File Systems}).
  11521. Note that the RAID level need not be given; it is chosen during the
  11522. initial creation and formatting of the RAID device and is determined
  11523. automatically later.
  11524. LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
  11525. be declared as follows:
  11526. @lisp
  11527. (mapped-device
  11528. (source "vg0")
  11529. (targets (list "vg0-alpha" "vg0-beta"))
  11530. (type lvm-device-mapping))
  11531. @end lisp
  11532. Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
  11533. then be used as the @code{device} of a @code{file-system} declaration
  11534. (@pxref{File Systems}).
  11535. @node User Accounts
  11536. @section User Accounts
  11537. @cindex users
  11538. @cindex accounts
  11539. @cindex user accounts
  11540. User accounts and groups are entirely managed through the
  11541. @code{operating-system} declaration. They are specified with the
  11542. @code{user-account} and @code{user-group} forms:
  11543. @lisp
  11544. (user-account
  11545. (name "alice")
  11546. (group "users")
  11547. (supplementary-groups '("wheel" ;allow use of sudo, etc.
  11548. "audio" ;sound card
  11549. "video" ;video devices such as webcams
  11550. "cdrom")) ;the good ol' CD-ROM
  11551. (comment "Bob's sister"))
  11552. @end lisp
  11553. Here's a user account that uses a different shell and a custom home
  11554. directory (the default would be @file{"/home/bob"}):
  11555. @lisp
  11556. (user-account
  11557. (name "bob")
  11558. (group "users")
  11559. (comment "Alice's bro")
  11560. (shell (file-append zsh "/bin/zsh"))
  11561. (home-directory "/home/robert"))
  11562. @end lisp
  11563. When booting or upon completion of @command{guix system reconfigure},
  11564. the system ensures that only the user accounts and groups specified in
  11565. the @code{operating-system} declaration exist, and with the specified
  11566. properties. Thus, account or group creations or modifications made by
  11567. directly invoking commands such as @command{useradd} are lost upon
  11568. reconfiguration or reboot. This ensures that the system remains exactly
  11569. as declared.
  11570. @deftp {Data Type} user-account
  11571. Objects of this type represent user accounts. The following members may
  11572. be specified:
  11573. @table @asis
  11574. @item @code{name}
  11575. The name of the user account.
  11576. @item @code{group}
  11577. @cindex groups
  11578. This is the name (a string) or identifier (a number) of the user group
  11579. this account belongs to.
  11580. @item @code{supplementary-groups} (default: @code{'()})
  11581. Optionally, this can be defined as a list of group names that this
  11582. account belongs to.
  11583. @item @code{uid} (default: @code{#f})
  11584. This is the user ID for this account (a number), or @code{#f}. In the
  11585. latter case, a number is automatically chosen by the system when the
  11586. account is created.
  11587. @item @code{comment} (default: @code{""})
  11588. A comment about the account, such as the account owner's full name.
  11589. @item @code{home-directory}
  11590. This is the name of the home directory for the account.
  11591. @item @code{create-home-directory?} (default: @code{#t})
  11592. Indicates whether the home directory of this account should be created
  11593. if it does not exist yet.
  11594. @item @code{shell} (default: Bash)
  11595. This is a G-expression denoting the file name of a program to be used as
  11596. the shell (@pxref{G-Expressions}). For example, you would refer to the
  11597. Bash executable like this:
  11598. @lisp
  11599. (file-append bash "/bin/bash")
  11600. @end lisp
  11601. @noindent
  11602. ... and to the Zsh executable like that:
  11603. @lisp
  11604. (file-append zsh "/bin/zsh")
  11605. @end lisp
  11606. @item @code{system?} (default: @code{#f})
  11607. This Boolean value indicates whether the account is a ``system''
  11608. account. System accounts are sometimes treated specially; for instance,
  11609. graphical login managers do not list them.
  11610. @anchor{user-account-password}
  11611. @cindex password, for user accounts
  11612. @item @code{password} (default: @code{#f})
  11613. You would normally leave this field to @code{#f}, initialize user
  11614. passwords as @code{root} with the @command{passwd} command, and then let
  11615. users change it with @command{passwd}. Passwords set with
  11616. @command{passwd} are of course preserved across reboot and
  11617. reconfiguration.
  11618. If you @emph{do} want to set an initial password for an account, then
  11619. this field must contain the encrypted password, as a string. You can use the
  11620. @code{crypt} procedure for this purpose:
  11621. @lisp
  11622. (user-account
  11623. (name "charlie")
  11624. (group "users")
  11625. ;; Specify a SHA-512-hashed initial password.
  11626. (password (crypt "InitialPassword!" "$6$abc")))
  11627. @end lisp
  11628. @quotation Note
  11629. The hash of this initial password will be available in a file in
  11630. @file{/gnu/store}, readable by all the users, so this method must be used with
  11631. care.
  11632. @end quotation
  11633. @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
  11634. more information on password encryption, and @ref{Encryption,,, guile, GNU
  11635. Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
  11636. @end table
  11637. @end deftp
  11638. @cindex groups
  11639. User group declarations are even simpler:
  11640. @lisp
  11641. (user-group (name "students"))
  11642. @end lisp
  11643. @deftp {Data Type} user-group
  11644. This type is for, well, user groups. There are just a few fields:
  11645. @table @asis
  11646. @item @code{name}
  11647. The name of the group.
  11648. @item @code{id} (default: @code{#f})
  11649. The group identifier (a number). If @code{#f}, a new number is
  11650. automatically allocated when the group is created.
  11651. @item @code{system?} (default: @code{#f})
  11652. This Boolean value indicates whether the group is a ``system'' group.
  11653. System groups have low numerical IDs.
  11654. @item @code{password} (default: @code{#f})
  11655. What, user groups can have a password? Well, apparently yes. Unless
  11656. @code{#f}, this field specifies the password of the group.
  11657. @end table
  11658. @end deftp
  11659. For convenience, a variable lists all the basic user groups one may
  11660. expect:
  11661. @defvr {Scheme Variable} %base-groups
  11662. This is the list of basic user groups that users and/or packages expect
  11663. to be present on the system. This includes groups such as ``root'',
  11664. ``wheel'', and ``users'', as well as groups used to control access to
  11665. specific devices such as ``audio'', ``disk'', and ``cdrom''.
  11666. @end defvr
  11667. @defvr {Scheme Variable} %base-user-accounts
  11668. This is the list of basic system accounts that programs may expect to
  11669. find on a GNU/Linux system, such as the ``nobody'' account.
  11670. Note that the ``root'' account is not included here. It is a
  11671. special-case and is automatically added whether or not it is specified.
  11672. @end defvr
  11673. @node Keyboard Layout
  11674. @section Keyboard Layout
  11675. @cindex keyboard layout
  11676. @cindex keymap
  11677. To specify what each key of your keyboard does, you need to tell the operating
  11678. system what @dfn{keyboard layout} you want to use. The default, when nothing
  11679. is specified, is the US English QWERTY layout for 105-key PC keyboards.
  11680. However, German speakers will usually prefer the German QWERTZ layout, French
  11681. speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
  11682. or bépo, and they might even want to further customize the effect of some of
  11683. the keys. This section explains how to get that done.
  11684. @cindex keyboard layout, definition
  11685. There are three components that will want to know about your keyboard layout:
  11686. @itemize
  11687. @item
  11688. The @emph{bootloader} may want to know what keyboard layout you want to use
  11689. (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
  11690. you want, for instance, to make sure that you can type the passphrase of your
  11691. encrypted root partition using the right layout.
  11692. @item
  11693. The @emph{operating system kernel}, Linux, will need that so that the console
  11694. is properly configured (@pxref{operating-system Reference,
  11695. @code{keyboard-layout}}).
  11696. @item
  11697. The @emph{graphical display server}, usually Xorg, also has its own idea of
  11698. the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
  11699. @end itemize
  11700. Guix allows you to configure all three separately but, fortunately, it allows
  11701. you to share the same keyboard layout for all three components.
  11702. @cindex XKB, keyboard layouts
  11703. Keyboard layouts are represented by records created by the
  11704. @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
  11705. the X Keyboard extension (XKB), each layout has four attributes: a name (often
  11706. a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
  11707. optional variant name, an optional keyboard model name, and a possibly empty
  11708. list of additional options. In most cases the layout name is all you care
  11709. about.
  11710. @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
  11711. [#:model] [#:options '()]
  11712. Return a new keyboard layout with the given @var{name} and @var{variant}.
  11713. @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
  11714. string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
  11715. @code{xkeyboard-config} package for valid options.
  11716. @end deffn
  11717. Here are a few examples:
  11718. @lisp
  11719. ;; The German QWERTZ layout. Here we assume a standard
  11720. ;; "pc105" keyboard model.
  11721. (keyboard-layout "de")
  11722. ;; The bépo variant of the French layout.
  11723. (keyboard-layout "fr" "bepo")
  11724. ;; The Catalan layout.
  11725. (keyboard-layout "es" "cat")
  11726. ;; Arabic layout with "Alt-Shift" to switch to US layout.
  11727. (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
  11728. ;; The Latin American Spanish layout. In addition, the
  11729. ;; "Caps Lock" key is used as an additional "Ctrl" key,
  11730. ;; and the "Menu" key is used as a "Compose" key to enter
  11731. ;; accented letters.
  11732. (keyboard-layout "latam"
  11733. #:options '("ctrl:nocaps" "compose:menu"))
  11734. ;; The Russian layout for a ThinkPad keyboard.
  11735. (keyboard-layout "ru" #:model "thinkpad")
  11736. ;; The "US international" layout, which is the US layout plus
  11737. ;; dead keys to enter accented characters. This is for an
  11738. ;; Apple MacBook keyboard.
  11739. (keyboard-layout "us" "intl" #:model "macbook78")
  11740. @end lisp
  11741. See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
  11742. for a complete list of supported layouts, variants, and models.
  11743. @cindex keyboard layout, configuration
  11744. Let's say you want your system to use the Turkish keyboard layout throughout
  11745. your system---bootloader, console, and Xorg. Here's what your system
  11746. configuration would look like:
  11747. @findex set-xorg-configuration
  11748. @lisp
  11749. ;; Using the Turkish layout for the bootloader, the console,
  11750. ;; and for Xorg.
  11751. (operating-system
  11752. ;; ...
  11753. (keyboard-layout (keyboard-layout "tr")) ;for the console
  11754. (bootloader (bootloader-configuration
  11755. (bootloader grub-efi-bootloader)
  11756. (target "/boot/efi")
  11757. (keyboard-layout keyboard-layout))) ;for GRUB
  11758. (services (cons (set-xorg-configuration
  11759. (xorg-configuration ;for Xorg
  11760. (keyboard-layout keyboard-layout)))
  11761. %desktop-services)))
  11762. @end lisp
  11763. In the example above, for GRUB and for Xorg, we just refer to the
  11764. @code{keyboard-layout} field defined above, but we could just as well refer to
  11765. a different layout. The @code{set-xorg-configuration} procedure communicates
  11766. the desired Xorg configuration to the graphical log-in manager, by default
  11767. GDM.
  11768. We've discussed how to specify the @emph{default} keyboard layout of your
  11769. system when it starts, but you can also adjust it at run time:
  11770. @itemize
  11771. @item
  11772. If you're using GNOME, its settings panel has a ``Region & Language'' entry
  11773. where you can select one or more keyboard layouts.
  11774. @item
  11775. Under Xorg, the @command{setxkbmap} command (from the same-named package)
  11776. allows you to change the current layout. For example, this is how you would
  11777. change the layout to US Dvorak:
  11778. @example
  11779. setxkbmap us dvorak
  11780. @end example
  11781. @item
  11782. The @code{loadkeys} command changes the keyboard layout in effect in the Linux
  11783. console. However, note that @code{loadkeys} does @emph{not} use the XKB
  11784. keyboard layout categorization described above. The command below loads the
  11785. French bépo layout:
  11786. @example
  11787. loadkeys fr-bepo
  11788. @end example
  11789. @end itemize
  11790. @node Locales
  11791. @section Locales
  11792. @cindex locale
  11793. A @dfn{locale} defines cultural conventions for a particular language
  11794. and region of the world (@pxref{Locales,,, libc, The GNU C Library
  11795. Reference Manual}). Each locale has a name that typically has the form
  11796. @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
  11797. @code{fr_LU.utf8} designates the locale for the French language, with
  11798. cultural conventions from Luxembourg, and using the UTF-8 encoding.
  11799. @cindex locale definition
  11800. Usually, you will want to specify the default locale for the machine
  11801. using the @code{locale} field of the @code{operating-system} declaration
  11802. (@pxref{operating-system Reference, @code{locale}}).
  11803. The selected locale is automatically added to the @dfn{locale
  11804. definitions} known to the system if needed, with its codeset inferred
  11805. from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
  11806. @code{UTF-8} codeset. Additional locale definitions can be specified in
  11807. the @code{locale-definitions} slot of @code{operating-system}---this is
  11808. useful, for instance, if the codeset could not be inferred from the
  11809. locale name. The default set of locale definitions includes some widely
  11810. used locales, but not all the available locales, in order to save space.
  11811. For instance, to add the North Frisian locale for Germany, the value of
  11812. that field may be:
  11813. @lisp
  11814. (cons (locale-definition
  11815. (name "fy_DE.utf8") (source "fy_DE"))
  11816. %default-locale-definitions)
  11817. @end lisp
  11818. Likewise, to save space, one might want @code{locale-definitions} to
  11819. list only the locales that are actually used, as in:
  11820. @lisp
  11821. (list (locale-definition
  11822. (name "ja_JP.eucjp") (source "ja_JP")
  11823. (charset "EUC-JP")))
  11824. @end lisp
  11825. @vindex LOCPATH
  11826. The compiled locale definitions are available at
  11827. @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
  11828. version, which is the default location where the GNU@tie{}libc provided
  11829. by Guix looks for locale data. This can be overridden using the
  11830. @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
  11831. @env{LOCPATH} and locale packages}).
  11832. The @code{locale-definition} form is provided by the @code{(gnu system
  11833. locale)} module. Details are given below.
  11834. @deftp {Data Type} locale-definition
  11835. This is the data type of a locale definition.
  11836. @table @asis
  11837. @item @code{name}
  11838. The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
  11839. Reference Manual}, for more information on locale names.
  11840. @item @code{source}
  11841. The name of the source for that locale. This is typically the
  11842. @code{@var{language}_@var{territory}} part of the locale name.
  11843. @item @code{charset} (default: @code{"UTF-8"})
  11844. The ``character set'' or ``code set'' for that locale,
  11845. @uref{https://www.iana.org/assignments/character-sets, as defined by
  11846. IANA}.
  11847. @end table
  11848. @end deftp
  11849. @defvr {Scheme Variable} %default-locale-definitions
  11850. A list of commonly used UTF-8 locales, used as the default
  11851. value of the @code{locale-definitions} field of @code{operating-system}
  11852. declarations.
  11853. @cindex locale name
  11854. @cindex normalized codeset in locale names
  11855. These locale definitions use the @dfn{normalized codeset} for the part
  11856. that follows the dot in the name (@pxref{Using gettextized software,
  11857. normalized codeset,, libc, The GNU C Library Reference Manual}). So for
  11858. instance it has @code{uk_UA.utf8} but @emph{not}, say,
  11859. @code{uk_UA.UTF-8}.
  11860. @end defvr
  11861. @subsection Locale Data Compatibility Considerations
  11862. @cindex incompatibility, of locale data
  11863. @code{operating-system} declarations provide a @code{locale-libcs} field
  11864. to specify the GNU@tie{}libc packages that are used to compile locale
  11865. declarations (@pxref{operating-system Reference}). ``Why would I
  11866. care?'', you may ask. Well, it turns out that the binary format of
  11867. locale data is occasionally incompatible from one libc version to
  11868. another.
  11869. @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
  11870. @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
  11871. For instance, a program linked against libc version 2.21 is unable to
  11872. read locale data produced with libc 2.22; worse, that program
  11873. @emph{aborts} instead of simply ignoring the incompatible locale
  11874. data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
  11875. the incompatible locale data, which is already an improvement.}.
  11876. Similarly, a program linked against libc 2.22 can read most, but not
  11877. all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
  11878. data is incompatible); thus calls to @code{setlocale} may fail, but
  11879. programs will not abort.
  11880. The ``problem'' with Guix is that users have a lot of freedom: They can
  11881. choose whether and when to upgrade software in their profiles, and might
  11882. be using a libc version different from the one the system administrator
  11883. used to build the system-wide locale data.
  11884. Fortunately, unprivileged users can also install their own locale data
  11885. and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
  11886. @env{GUIX_LOCPATH} and locale packages}).
  11887. Still, it is best if the system-wide locale data at
  11888. @file{/run/current-system/locale} is built for all the libc versions
  11889. actually in use on the system, so that all the programs can access
  11890. it---this is especially crucial on a multi-user system. To do that, the
  11891. administrator can specify several libc packages in the
  11892. @code{locale-libcs} field of @code{operating-system}:
  11893. @lisp
  11894. (use-package-modules base)
  11895. (operating-system
  11896. ;; @dots{}
  11897. (locale-libcs (list glibc-2.21 (canonical-package glibc))))
  11898. @end lisp
  11899. This example would lead to a system containing locale definitions for
  11900. both libc 2.21 and the current version of libc in
  11901. @file{/run/current-system/locale}.
  11902. @node Services
  11903. @section Services
  11904. @cindex system services
  11905. An important part of preparing an @code{operating-system} declaration is
  11906. listing @dfn{system services} and their configuration (@pxref{Using the
  11907. Configuration System}). System services are typically daemons launched
  11908. when the system boots, or other actions needed at that time---e.g.,
  11909. configuring network access.
  11910. Guix has a broad definition of ``service'' (@pxref{Service
  11911. Composition}), but many services are managed by the GNU@tie{}Shepherd
  11912. (@pxref{Shepherd Services}). On a running system, the @command{herd}
  11913. command allows you to list the available services, show their status,
  11914. start and stop them, or do other specific operations (@pxref{Jump
  11915. Start,,, shepherd, The GNU Shepherd Manual}). For example:
  11916. @example
  11917. # herd status
  11918. @end example
  11919. The above command, run as @code{root}, lists the currently defined
  11920. services. The @command{herd doc} command shows a synopsis of the given
  11921. service and its associated actions:
  11922. @example
  11923. # herd doc nscd
  11924. Run libc's name service cache daemon (nscd).
  11925. # herd doc nscd action invalidate
  11926. invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
  11927. @end example
  11928. The @command{start}, @command{stop}, and @command{restart} sub-commands
  11929. have the effect you would expect. For instance, the commands below stop
  11930. the nscd service and restart the Xorg display server:
  11931. @example
  11932. # herd stop nscd
  11933. Service nscd has been stopped.
  11934. # herd restart xorg-server
  11935. Service xorg-server has been stopped.
  11936. Service xorg-server has been started.
  11937. @end example
  11938. The following sections document the available services, starting with
  11939. the core services, that may be used in an @code{operating-system}
  11940. declaration.
  11941. @menu
  11942. * Base Services:: Essential system services.
  11943. * Scheduled Job Execution:: The mcron service.
  11944. * Log Rotation:: The rottlog service.
  11945. * Networking Services:: Network setup, SSH daemon, etc.
  11946. * Unattended Upgrades:: Automated system upgrades.
  11947. * X Window:: Graphical display.
  11948. * Printing Services:: Local and remote printer support.
  11949. * Desktop Services:: D-Bus and desktop services.
  11950. * Sound Services:: ALSA and Pulseaudio services.
  11951. * Database Services:: SQL databases, key-value stores, etc.
  11952. * Mail Services:: IMAP, POP3, SMTP, and all that.
  11953. * Messaging Services:: Messaging services.
  11954. * Telephony Services:: Telephony services.
  11955. * File-Sharing Services:: File-sharing services.
  11956. * Monitoring Services:: Monitoring services.
  11957. * Kerberos Services:: Kerberos services.
  11958. * LDAP Services:: LDAP services.
  11959. * Web Services:: Web servers.
  11960. * Certificate Services:: TLS certificates via Let's Encrypt.
  11961. * DNS Services:: DNS daemons.
  11962. * VPN Services:: VPN daemons.
  11963. * Network File System:: NFS related services.
  11964. * Continuous Integration:: The Cuirass service.
  11965. * Power Management Services:: Extending battery life.
  11966. * Audio Services:: The MPD.
  11967. * Virtualization Services:: Virtualization services.
  11968. * Version Control Services:: Providing remote access to Git repositories.
  11969. * Game Services:: Game servers.
  11970. * PAM Mount Service:: Service to mount volumes when logging in.
  11971. * Guix Services:: Services relating specifically to Guix.
  11972. * Linux Services:: Services tied to the Linux kernel.
  11973. * Hurd Services:: Services specific for a Hurd System.
  11974. * Miscellaneous Services:: Other services.
  11975. @end menu
  11976. @node Base Services
  11977. @subsection Base Services
  11978. The @code{(gnu services base)} module provides definitions for the basic
  11979. services that one expects from the system. The services exported by
  11980. this module are listed below.
  11981. @defvr {Scheme Variable} %base-services
  11982. This variable contains a list of basic services (@pxref{Service Types
  11983. and Services}, for more information on service objects) one would
  11984. expect from the system: a login service (mingetty) on each tty, syslogd,
  11985. the libc name service cache daemon (nscd), the udev device manager, and
  11986. more.
  11987. This is the default value of the @code{services} field of
  11988. @code{operating-system} declarations. Usually, when customizing a
  11989. system, you will want to append services to @code{%base-services}, like
  11990. this:
  11991. @lisp
  11992. (append (list (service avahi-service-type)
  11993. (service openssh-service-type))
  11994. %base-services)
  11995. @end lisp
  11996. @end defvr
  11997. @defvr {Scheme Variable} special-files-service-type
  11998. This is the service that sets up ``special files'' such as
  11999. @file{/bin/sh}; an instance of it is part of @code{%base-services}.
  12000. The value associated with @code{special-files-service-type} services
  12001. must be a list of tuples where the first element is the ``special file''
  12002. and the second element is its target. By default it is:
  12003. @cindex @file{/bin/sh}
  12004. @cindex @file{sh}, in @file{/bin}
  12005. @lisp
  12006. `(("/bin/sh" ,(file-append bash "/bin/sh")))
  12007. @end lisp
  12008. @cindex @file{/usr/bin/env}
  12009. @cindex @file{env}, in @file{/usr/bin}
  12010. If you want to add, say, @code{/usr/bin/env} to your system, you can
  12011. change it to:
  12012. @lisp
  12013. `(("/bin/sh" ,(file-append bash "/bin/sh"))
  12014. ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
  12015. @end lisp
  12016. Since this is part of @code{%base-services}, you can use
  12017. @code{modify-services} to customize the set of special files
  12018. (@pxref{Service Reference, @code{modify-services}}). But the simple way
  12019. to add a special file is @i{via} the @code{extra-special-file} procedure
  12020. (see below).
  12021. @end defvr
  12022. @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
  12023. Use @var{target} as the ``special file'' @var{file}.
  12024. For example, adding the following lines to the @code{services} field of
  12025. your operating system declaration leads to a @file{/usr/bin/env}
  12026. symlink:
  12027. @lisp
  12028. (extra-special-file "/usr/bin/env"
  12029. (file-append coreutils "/bin/env"))
  12030. @end lisp
  12031. @end deffn
  12032. @deffn {Scheme Procedure} host-name-service @var{name}
  12033. Return a service that sets the host name to @var{name}.
  12034. @end deffn
  12035. @defvr {Scheme Variable} console-font-service-type
  12036. Install the given fonts on the specified ttys (fonts are per
  12037. virtual console on the kernel Linux). The value of this service is a list of
  12038. tty/font pairs. The font can be the name of a font provided by the @code{kbd}
  12039. package or any valid argument to @command{setfont}, as in this example:
  12040. @lisp
  12041. `(("tty1" . "LatGrkCyr-8x16")
  12042. ("tty2" . ,(file-append
  12043. font-tamzen
  12044. "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
  12045. ("tty3" . ,(file-append
  12046. font-terminus
  12047. "/share/consolefonts/ter-132n"))) ; for HDPI
  12048. @end lisp
  12049. @end defvr
  12050. @deffn {Scheme Procedure} login-service @var{config}
  12051. Return a service to run login according to @var{config}, a
  12052. @code{<login-configuration>} object, which specifies the message of the day,
  12053. among other things.
  12054. @end deffn
  12055. @deftp {Data Type} login-configuration
  12056. This is the data type representing the configuration of login.
  12057. @table @asis
  12058. @item @code{motd}
  12059. @cindex message of the day
  12060. A file-like object containing the ``message of the day''.
  12061. @item @code{allow-empty-passwords?} (default: @code{#t})
  12062. Allow empty passwords by default so that first-time users can log in when
  12063. the 'root' account has just been created.
  12064. @end table
  12065. @end deftp
  12066. @deffn {Scheme Procedure} mingetty-service @var{config}
  12067. Return a service to run mingetty according to @var{config}, a
  12068. @code{<mingetty-configuration>} object, which specifies the tty to run, among
  12069. other things.
  12070. @end deffn
  12071. @deftp {Data Type} mingetty-configuration
  12072. This is the data type representing the configuration of Mingetty, which
  12073. provides the default implementation of virtual console log-in.
  12074. @table @asis
  12075. @item @code{tty}
  12076. The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
  12077. @item @code{auto-login} (default: @code{#f})
  12078. When true, this field must be a string denoting the user name under
  12079. which the system automatically logs in. When it is @code{#f}, a
  12080. user name and password must be entered to log in.
  12081. @item @code{login-program} (default: @code{#f})
  12082. This must be either @code{#f}, in which case the default log-in program
  12083. is used (@command{login} from the Shadow tool suite), or a gexp denoting
  12084. the name of the log-in program.
  12085. @item @code{login-pause?} (default: @code{#f})
  12086. When set to @code{#t} in conjunction with @var{auto-login}, the user
  12087. will have to press a key before the log-in shell is launched.
  12088. @item @code{clear-on-logout?} (default: @code{#t})
  12089. When set to @code{#t}, the screen will be cleared after logout.
  12090. @item @code{mingetty} (default: @var{mingetty})
  12091. The Mingetty package to use.
  12092. @end table
  12093. @end deftp
  12094. @deffn {Scheme Procedure} agetty-service @var{config}
  12095. Return a service to run agetty according to @var{config}, an
  12096. @code{<agetty-configuration>} object, which specifies the tty to run,
  12097. among other things.
  12098. @end deffn
  12099. @deftp {Data Type} agetty-configuration
  12100. This is the data type representing the configuration of agetty, which
  12101. implements virtual and serial console log-in. See the @code{agetty(8)}
  12102. man page for more information.
  12103. @table @asis
  12104. @item @code{tty}
  12105. The name of the console this agetty runs on, as a string---e.g.,
  12106. @code{"ttyS0"}. This argument is optional, it will default to
  12107. a reasonable default serial port used by the kernel Linux.
  12108. For this, if there is a value for an option @code{agetty.tty} in the kernel
  12109. command line, agetty will extract the device name of the serial port
  12110. from it and use that.
  12111. If not and if there is a value for an option @code{console} with a tty in
  12112. the Linux command line, agetty will extract the device name of the
  12113. serial port from it and use that.
  12114. In both cases, agetty will leave the other serial device settings
  12115. (baud rate etc.)@: alone---in the hope that Linux pinned them to the
  12116. correct values.
  12117. @item @code{baud-rate} (default: @code{#f})
  12118. A string containing a comma-separated list of one or more baud rates, in
  12119. descending order.
  12120. @item @code{term} (default: @code{#f})
  12121. A string containing the value used for the @env{TERM} environment
  12122. variable.
  12123. @item @code{eight-bits?} (default: @code{#f})
  12124. When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
  12125. disabled.
  12126. @item @code{auto-login} (default: @code{#f})
  12127. When passed a login name, as a string, the specified user will be logged
  12128. in automatically without prompting for their login name or password.
  12129. @item @code{no-reset?} (default: @code{#f})
  12130. When @code{#t}, don't reset terminal cflags (control modes).
  12131. @item @code{host} (default: @code{#f})
  12132. This accepts a string containing the ``login_host'', which will be written
  12133. into the @file{/var/run/utmpx} file.
  12134. @item @code{remote?} (default: @code{#f})
  12135. When set to @code{#t} in conjunction with @var{host}, this will add an
  12136. @code{-r} fakehost option to the command line of the login program
  12137. specified in @var{login-program}.
  12138. @item @code{flow-control?} (default: @code{#f})
  12139. When set to @code{#t}, enable hardware (RTS/CTS) flow control.
  12140. @item @code{no-issue?} (default: @code{#f})
  12141. When set to @code{#t}, the contents of the @file{/etc/issue} file will
  12142. not be displayed before presenting the login prompt.
  12143. @item @code{init-string} (default: @code{#f})
  12144. This accepts a string that will be sent to the tty or modem before
  12145. sending anything else. It can be used to initialize a modem.
  12146. @item @code{no-clear?} (default: @code{#f})
  12147. When set to @code{#t}, agetty will not clear the screen before showing
  12148. the login prompt.
  12149. @item @code{login-program} (default: (file-append shadow "/bin/login"))
  12150. This must be either a gexp denoting the name of a log-in program, or
  12151. unset, in which case the default value is the @command{login} from the
  12152. Shadow tool suite.
  12153. @item @code{local-line} (default: @code{#f})
  12154. Control the CLOCAL line flag. This accepts one of three symbols as
  12155. arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
  12156. the default value chosen by agetty is @code{'auto}.
  12157. @item @code{extract-baud?} (default: @code{#f})
  12158. When set to @code{#t}, instruct agetty to try to extract the baud rate
  12159. from the status messages produced by certain types of modems.
  12160. @item @code{skip-login?} (default: @code{#f})
  12161. When set to @code{#t}, do not prompt the user for a login name. This
  12162. can be used with @var{login-program} field to use non-standard login
  12163. systems.
  12164. @item @code{no-newline?} (default: @code{#f})
  12165. When set to @code{#t}, do not print a newline before printing the
  12166. @file{/etc/issue} file.
  12167. @c Is this dangerous only when used with login-program, or always?
  12168. @item @code{login-options} (default: @code{#f})
  12169. This option accepts a string containing options that are passed to the
  12170. login program. When used with the @var{login-program}, be aware that a
  12171. malicious user could try to enter a login name containing embedded
  12172. options that could be parsed by the login program.
  12173. @item @code{login-pause} (default: @code{#f})
  12174. When set to @code{#t}, wait for any key before showing the login prompt.
  12175. This can be used in conjunction with @var{auto-login} to save memory by
  12176. lazily spawning shells.
  12177. @item @code{chroot} (default: @code{#f})
  12178. Change root to the specified directory. This option accepts a directory
  12179. path as a string.
  12180. @item @code{hangup?} (default: @code{#f})
  12181. Use the Linux system call @code{vhangup} to do a virtual hangup of the
  12182. specified terminal.
  12183. @item @code{keep-baud?} (default: @code{#f})
  12184. When set to @code{#t}, try to keep the existing baud rate. The baud
  12185. rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
  12186. character.
  12187. @item @code{timeout} (default: @code{#f})
  12188. When set to an integer value, terminate if no user name could be read
  12189. within @var{timeout} seconds.
  12190. @item @code{detect-case?} (default: @code{#f})
  12191. When set to @code{#t}, turn on support for detecting an uppercase-only
  12192. terminal. This setting will detect a login name containing only
  12193. uppercase letters as indicating an uppercase-only terminal and turn on
  12194. some upper-to-lower case conversions. Note that this will not support
  12195. Unicode characters.
  12196. @item @code{wait-cr?} (default: @code{#f})
  12197. When set to @code{#t}, wait for the user or modem to send a
  12198. carriage-return or linefeed character before displaying
  12199. @file{/etc/issue} or login prompt. This is typically used with the
  12200. @var{init-string} option.
  12201. @item @code{no-hints?} (default: @code{#f})
  12202. When set to @code{#t}, do not print hints about Num, Caps, and Scroll
  12203. locks.
  12204. @item @code{no-hostname?} (default: @code{#f})
  12205. By default, the hostname is printed. When this option is set to
  12206. @code{#t}, no hostname will be shown at all.
  12207. @item @code{long-hostname?} (default: @code{#f})
  12208. By default, the hostname is only printed until the first dot. When this
  12209. option is set to @code{#t}, the fully qualified hostname by
  12210. @code{gethostname} or @code{getaddrinfo} is shown.
  12211. @item @code{erase-characters} (default: @code{#f})
  12212. This option accepts a string of additional characters that should be
  12213. interpreted as backspace when the user types their login name.
  12214. @item @code{kill-characters} (default: @code{#f})
  12215. This option accepts a string that should be interpreted to mean ``ignore
  12216. all previous characters'' (also called a ``kill'' character) when the user
  12217. types their login name.
  12218. @item @code{chdir} (default: @code{#f})
  12219. This option accepts, as a string, a directory path that will be changed
  12220. to before login.
  12221. @item @code{delay} (default: @code{#f})
  12222. This options accepts, as an integer, the number of seconds to sleep
  12223. before opening the tty and displaying the login prompt.
  12224. @item @code{nice} (default: @code{#f})
  12225. This option accepts, as an integer, the nice value with which to run the
  12226. @command{login} program.
  12227. @item @code{extra-options} (default: @code{'()})
  12228. This option provides an ``escape hatch'' for the user to provide arbitrary
  12229. command-line arguments to @command{agetty} as a list of strings.
  12230. @end table
  12231. @end deftp
  12232. @deffn {Scheme Procedure} kmscon-service-type @var{config}
  12233. Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
  12234. according to @var{config}, a @code{<kmscon-configuration>} object, which
  12235. specifies the tty to run, among other things.
  12236. @end deffn
  12237. @deftp {Data Type} kmscon-configuration
  12238. This is the data type representing the configuration of Kmscon, which
  12239. implements virtual console log-in.
  12240. @table @asis
  12241. @item @code{virtual-terminal}
  12242. The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
  12243. @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
  12244. A gexp denoting the name of the log-in program. The default log-in program is
  12245. @command{login} from the Shadow tool suite.
  12246. @item @code{login-arguments} (default: @code{'("-p")})
  12247. A list of arguments to pass to @command{login}.
  12248. @item @code{auto-login} (default: @code{#f})
  12249. When passed a login name, as a string, the specified user will be logged
  12250. in automatically without prompting for their login name or password.
  12251. @item @code{hardware-acceleration?} (default: #f)
  12252. Whether to use hardware acceleration.
  12253. @item @code{kmscon} (default: @var{kmscon})
  12254. The Kmscon package to use.
  12255. @end table
  12256. @end deftp
  12257. @cindex name service cache daemon
  12258. @cindex nscd
  12259. @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
  12260. [#:name-services '()]
  12261. Return a service that runs the libc name service cache daemon (nscd) with the
  12262. given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
  12263. Service Switch}, for an example.
  12264. For convenience, the Shepherd service for nscd provides the following actions:
  12265. @table @code
  12266. @item invalidate
  12267. @cindex cache invalidation, nscd
  12268. @cindex nscd, cache invalidation
  12269. This invalidate the given cache. For instance, running:
  12270. @example
  12271. herd invalidate nscd hosts
  12272. @end example
  12273. @noindent
  12274. invalidates the host name lookup cache of nscd.
  12275. @item statistics
  12276. Running @command{herd statistics nscd} displays information about nscd usage
  12277. and caches.
  12278. @end table
  12279. @end deffn
  12280. @defvr {Scheme Variable} %nscd-default-configuration
  12281. This is the default @code{<nscd-configuration>} value (see below) used
  12282. by @code{nscd-service}. It uses the caches defined by
  12283. @code{%nscd-default-caches}; see below.
  12284. @end defvr
  12285. @deftp {Data Type} nscd-configuration
  12286. This is the data type representing the name service cache daemon (nscd)
  12287. configuration.
  12288. @table @asis
  12289. @item @code{name-services} (default: @code{'()})
  12290. List of packages denoting @dfn{name services} that must be visible to
  12291. the nscd---e.g., @code{(list @var{nss-mdns})}.
  12292. @item @code{glibc} (default: @var{glibc})
  12293. Package object denoting the GNU C Library providing the @command{nscd}
  12294. command.
  12295. @item @code{log-file} (default: @code{"/var/log/nscd.log"})
  12296. Name of the nscd log file. This is where debugging output goes when
  12297. @code{debug-level} is strictly positive.
  12298. @item @code{debug-level} (default: @code{0})
  12299. Integer denoting the debugging levels. Higher numbers mean that more
  12300. debugging output is logged.
  12301. @item @code{caches} (default: @code{%nscd-default-caches})
  12302. List of @code{<nscd-cache>} objects denoting things to be cached; see
  12303. below.
  12304. @end table
  12305. @end deftp
  12306. @deftp {Data Type} nscd-cache
  12307. Data type representing a cache database of nscd and its parameters.
  12308. @table @asis
  12309. @item @code{database}
  12310. This is a symbol representing the name of the database to be cached.
  12311. Valid values are @code{passwd}, @code{group}, @code{hosts}, and
  12312. @code{services}, which designate the corresponding NSS database
  12313. (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
  12314. @item @code{positive-time-to-live}
  12315. @itemx @code{negative-time-to-live} (default: @code{20})
  12316. A number representing the number of seconds during which a positive or
  12317. negative lookup result remains in cache.
  12318. @item @code{check-files?} (default: @code{#t})
  12319. Whether to check for updates of the files corresponding to
  12320. @var{database}.
  12321. For instance, when @var{database} is @code{hosts}, setting this flag
  12322. instructs nscd to check for updates in @file{/etc/hosts} and to take
  12323. them into account.
  12324. @item @code{persistent?} (default: @code{#t})
  12325. Whether the cache should be stored persistently on disk.
  12326. @item @code{shared?} (default: @code{#t})
  12327. Whether the cache should be shared among users.
  12328. @item @code{max-database-size} (default: 32@tie{}MiB)
  12329. Maximum size in bytes of the database cache.
  12330. @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
  12331. @c settings, so leave them out.
  12332. @end table
  12333. @end deftp
  12334. @defvr {Scheme Variable} %nscd-default-caches
  12335. List of @code{<nscd-cache>} objects used by default by
  12336. @code{nscd-configuration} (see above).
  12337. It enables persistent and aggressive caching of service and host name
  12338. lookups. The latter provides better host name lookup performance,
  12339. resilience in the face of unreliable name servers, and also better
  12340. privacy---often the result of host name lookups is in local cache, so
  12341. external name servers do not even need to be queried.
  12342. @end defvr
  12343. @anchor{syslog-configuration-type}
  12344. @cindex syslog
  12345. @cindex logging
  12346. @deftp {Data Type} syslog-configuration
  12347. This data type represents the configuration of the syslog daemon.
  12348. @table @asis
  12349. @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
  12350. The syslog daemon to use.
  12351. @item @code{config-file} (default: @code{%default-syslog.conf})
  12352. The syslog configuration file to use.
  12353. @end table
  12354. @end deftp
  12355. @anchor{syslog-service}
  12356. @cindex syslog
  12357. @deffn {Scheme Procedure} syslog-service @var{config}
  12358. Return a service that runs a syslog daemon according to @var{config}.
  12359. @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
  12360. information on the configuration file syntax.
  12361. @end deffn
  12362. @defvr {Scheme Variable} guix-service-type
  12363. This is the type of the service that runs the build daemon,
  12364. @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
  12365. @code{guix-configuration} record as described below.
  12366. @end defvr
  12367. @anchor{guix-configuration-type}
  12368. @deftp {Data Type} guix-configuration
  12369. This data type represents the configuration of the Guix build daemon.
  12370. @xref{Invoking guix-daemon}, for more information.
  12371. @table @asis
  12372. @item @code{guix} (default: @var{guix})
  12373. The Guix package to use.
  12374. @item @code{build-group} (default: @code{"guixbuild"})
  12375. Name of the group for build user accounts.
  12376. @item @code{build-accounts} (default: @code{10})
  12377. Number of build user accounts to create.
  12378. @item @code{authorize-key?} (default: @code{#t})
  12379. @cindex substitutes, authorization thereof
  12380. Whether to authorize the substitute keys listed in
  12381. @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
  12382. (@pxref{Substitutes}).
  12383. When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
  12384. changed by invoking @command{guix archive --authorize}. You must
  12385. instead adjust @code{guix-configuration} as you wish and reconfigure the
  12386. system. This ensures that your operating system configuration file is
  12387. self-contained.
  12388. @quotation Note
  12389. When booting or reconfiguring to a system where @code{authorize-key?}
  12390. is true, the existing @file{/etc/guix/acl} file is backed up as
  12391. @file{/etc/guix/acl.bak} if it was determined to be a manually modified
  12392. file. This is to facilitate migration from earlier versions, which
  12393. allowed for in-place modifications to @file{/etc/guix/acl}.
  12394. @end quotation
  12395. @vindex %default-authorized-guix-keys
  12396. @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
  12397. The list of authorized key files for archive imports, as a list of
  12398. string-valued gexps (@pxref{Invoking guix archive}). By default, it
  12399. contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
  12400. See @code{substitute-urls} below for an example on how to change it.
  12401. @item @code{use-substitutes?} (default: @code{#t})
  12402. Whether to use substitutes.
  12403. @item @code{substitute-urls} (default: @code{%default-substitute-urls})
  12404. The list of URLs where to look for substitutes by default.
  12405. Suppose you would like to fetch substitutes from @code{guix.example.org}
  12406. in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
  12407. two things: (1) add @code{guix.example.org} to @code{substitute-urls},
  12408. and (2) authorize its signing key, having done appropriate checks
  12409. (@pxref{Substitute Server Authorization}). The configuration below does
  12410. exactly that:
  12411. @lisp
  12412. (guix-configuration
  12413. (substitute-urls
  12414. (append (list "https://guix.example.org")
  12415. %default-substitute-urls))
  12416. (authorized-keys
  12417. (append (list (local-file "./guix.example.org-key.pub"))
  12418. %default-authorized-guix-keys)))
  12419. @end lisp
  12420. This example assumes that the file @file{./guix.example.org-key.pub}
  12421. contains the public key that @code{guix.example.org} uses to sign
  12422. substitutes.
  12423. @item @code{max-silent-time} (default: @code{0})
  12424. @itemx @code{timeout} (default: @code{0})
  12425. The number of seconds of silence and the number of seconds of activity,
  12426. respectively, after which a build process times out. A value of zero
  12427. disables the timeout.
  12428. @item @code{log-compression} (default: @code{'bzip2})
  12429. The type of compression used for build logs---one of @code{gzip},
  12430. @code{bzip2}, or @code{none}.
  12431. @item @code{discover?} (default: @code{#f})
  12432. Whether to discover substitute servers on the local network using mDNS
  12433. and DNS-SD.
  12434. @item @code{extra-options} (default: @code{'()})
  12435. List of extra command-line options for @command{guix-daemon}.
  12436. @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
  12437. File where @command{guix-daemon}'s standard output and standard error
  12438. are written.
  12439. @cindex HTTP proxy, for @code{guix-daemon}
  12440. @cindex proxy, for @code{guix-daemon} HTTP access
  12441. @item @code{http-proxy} (default: @code{#f})
  12442. The URL of the HTTP and HTTPS proxy used for downloading fixed-output
  12443. derivations and substitutes.
  12444. It is also possible to change the daemon's proxy at run time through the
  12445. @code{set-http-proxy} action, which restarts it:
  12446. @example
  12447. herd set-http-proxy guix-daemon http://localhost:8118
  12448. @end example
  12449. To clear the proxy settings, run:
  12450. @example
  12451. herd set-http-proxy guix-daemon
  12452. @end example
  12453. @item @code{tmpdir} (default: @code{#f})
  12454. A directory path where the @command{guix-daemon} will perform builds.
  12455. @end table
  12456. @end deftp
  12457. @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
  12458. Run @var{udev}, which populates the @file{/dev} directory dynamically.
  12459. udev rules can be provided as a list of files through the @var{rules}
  12460. variable. The procedures @code{udev-rule}, @code{udev-rules-service}
  12461. and @code{file->udev-rule} from @code{(gnu services base)} simplify the
  12462. creation of such rule files.
  12463. The @command{herd rules udev} command, as root, returns the name of the
  12464. directory containing all the active udev rules.
  12465. @end deffn
  12466. @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
  12467. Return a udev-rule file named @var{file-name} containing the rules
  12468. defined by the @var{contents} literal.
  12469. In the following example, a rule for a USB device is defined to be
  12470. stored in the file @file{90-usb-thing.rules}. The rule runs a script
  12471. upon detecting a USB device with a given product identifier.
  12472. @lisp
  12473. (define %example-udev-rule
  12474. (udev-rule
  12475. "90-usb-thing.rules"
  12476. (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
  12477. "ATTR@{product@}==\"Example\", "
  12478. "RUN+=\"/path/to/script\"")))
  12479. @end lisp
  12480. @end deffn
  12481. @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
  12482. [#:groups @var{groups}]
  12483. Return a service that extends @code{udev-service-type } with @var{rules}
  12484. and @code{account-service-type} with @var{groups} as system groups.
  12485. This works by creating a singleton service type
  12486. @code{@var{name}-udev-rules}, of which the returned service is an
  12487. instance.
  12488. Here we show how it can be used to extend @code{udev-service-type} with the
  12489. previously defined rule @code{%example-udev-rule}.
  12490. @lisp
  12491. (operating-system
  12492. ;; @dots{}
  12493. (services
  12494. (cons (udev-rules-service 'usb-thing %example-udev-rule)
  12495. %desktop-services)))
  12496. @end lisp
  12497. @end deffn
  12498. @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
  12499. Return a udev file named @var{file-name} containing the rules defined
  12500. within @var{file}, a file-like object.
  12501. The following example showcases how we can use an existing rule file.
  12502. @lisp
  12503. (use-modules (guix download) ;for url-fetch
  12504. (guix packages) ;for origin
  12505. @dots{})
  12506. (define %android-udev-rules
  12507. (file->udev-rule
  12508. "51-android-udev.rules"
  12509. (let ((version "20170910"))
  12510. (origin
  12511. (method url-fetch)
  12512. (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
  12513. "android-udev-rules/" version "/51-android.rules"))
  12514. (sha256
  12515. (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
  12516. @end lisp
  12517. @end deffn
  12518. Additionally, Guix package definitions can be included in @var{rules} in
  12519. order to extend the udev rules with the definitions found under their
  12520. @file{lib/udev/rules.d} sub-directory. In lieu of the previous
  12521. @var{file->udev-rule} example, we could have used the
  12522. @var{android-udev-rules} package which exists in Guix in the @code{(gnu
  12523. packages android)} module.
  12524. The following example shows how to use the @var{android-udev-rules}
  12525. package so that the Android tool @command{adb} can detect devices
  12526. without root privileges. It also details how to create the
  12527. @code{adbusers} group, which is required for the proper functioning of
  12528. the rules defined within the @code{android-udev-rules} package. To
  12529. create such a group, we must define it both as part of the
  12530. @code{supplementary-groups} of our @code{user-account} declaration, as
  12531. well as in the @var{groups} of the @code{udev-rules-service} procedure.
  12532. @lisp
  12533. (use-modules (gnu packages android) ;for android-udev-rules
  12534. (gnu system shadow) ;for user-group
  12535. @dots{})
  12536. (operating-system
  12537. ;; @dots{}
  12538. (users (cons (user-account
  12539. ;; @dots{}
  12540. (supplementary-groups
  12541. '("adbusers" ;for adb
  12542. "wheel" "netdev" "audio" "video")))))
  12543. ;; @dots{}
  12544. (services
  12545. (cons (udev-rules-service 'android android-udev-rules
  12546. #:groups '("adbusers"))
  12547. %desktop-services)))
  12548. @end lisp
  12549. @defvr {Scheme Variable} urandom-seed-service-type
  12550. Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
  12551. when rebooting. It also tries to seed @file{/dev/urandom} from
  12552. @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
  12553. readable.
  12554. @end defvr
  12555. @defvr {Scheme Variable} %random-seed-file
  12556. This is the name of the file where some random bytes are saved by
  12557. @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
  12558. It defaults to @file{/var/lib/random-seed}.
  12559. @end defvr
  12560. @cindex mouse
  12561. @cindex gpm
  12562. @defvr {Scheme Variable} gpm-service-type
  12563. This is the type of the service that runs GPM, the @dfn{general-purpose
  12564. mouse daemon}, which provides mouse support to the Linux console. GPM
  12565. allows users to use the mouse in the console, notably to select, copy,
  12566. and paste text.
  12567. The value for services of this type must be a @code{gpm-configuration}
  12568. (see below). This service is not part of @code{%base-services}.
  12569. @end defvr
  12570. @deftp {Data Type} gpm-configuration
  12571. Data type representing the configuration of GPM.
  12572. @table @asis
  12573. @item @code{options} (default: @code{%default-gpm-options})
  12574. Command-line options passed to @command{gpm}. The default set of
  12575. options instruct @command{gpm} to listen to mouse events on
  12576. @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
  12577. more information.
  12578. @item @code{gpm} (default: @code{gpm})
  12579. The GPM package to use.
  12580. @end table
  12581. @end deftp
  12582. @anchor{guix-publish-service-type}
  12583. @deffn {Scheme Variable} guix-publish-service-type
  12584. This is the service type for @command{guix publish} (@pxref{Invoking
  12585. guix publish}). Its value must be a @code{guix-publish-configuration}
  12586. object, as described below.
  12587. This assumes that @file{/etc/guix} already contains a signing key pair as
  12588. created by @command{guix archive --generate-key} (@pxref{Invoking guix
  12589. archive}). If that is not the case, the service will fail to start.
  12590. @end deffn
  12591. @deftp {Data Type} guix-publish-configuration
  12592. Data type representing the configuration of the @code{guix publish}
  12593. service.
  12594. @table @asis
  12595. @item @code{guix} (default: @code{guix})
  12596. The Guix package to use.
  12597. @item @code{port} (default: @code{80})
  12598. The TCP port to listen for connections.
  12599. @item @code{host} (default: @code{"localhost"})
  12600. The host (and thus, network interface) to listen to. Use
  12601. @code{"0.0.0.0"} to listen on all the network interfaces.
  12602. @item @code{advertise?} (default: @code{#f})
  12603. When true, advertise the service on the local network @i{via} the DNS-SD
  12604. protocol, using Avahi.
  12605. This allows neighboring Guix devices with discovery on (see
  12606. @code{guix-configuration} above) to discover this @command{guix publish}
  12607. instance and to automatically download substitutes from it.
  12608. @item @code{compression} (default: @code{'(("gzip" 3))})
  12609. This is a list of compression method/level tuple used when compressing
  12610. substitutes. For example, to compress all substitutes with @emph{both} lzip
  12611. at level 7 and gzip at level 9, write:
  12612. @lisp
  12613. '(("lzip" 7) ("gzip" 9))
  12614. @end lisp
  12615. Level 9 achieves the best compression ratio at the expense of increased CPU
  12616. usage, whereas level 1 achieves fast compression. @xref{Invoking guix
  12617. publish}, for more information on the available compression methods and
  12618. the tradeoffs involved.
  12619. An empty list disables compression altogether.
  12620. @item @code{nar-path} (default: @code{"nar"})
  12621. The URL path at which ``nars'' can be fetched. @xref{Invoking guix
  12622. publish, @option{--nar-path}}, for details.
  12623. @item @code{cache} (default: @code{#f})
  12624. When it is @code{#f}, disable caching and instead generate archives on
  12625. demand. Otherwise, this should be the name of a directory---e.g.,
  12626. @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
  12627. archives and meta-data ready to be sent. @xref{Invoking guix publish,
  12628. @option{--cache}}, for more information on the tradeoffs involved.
  12629. @item @code{workers} (default: @code{#f})
  12630. When it is an integer, this is the number of worker threads used for
  12631. caching; when @code{#f}, the number of processors is used.
  12632. @xref{Invoking guix publish, @option{--workers}}, for more information.
  12633. @item @code{cache-bypass-threshold} (default: 10 MiB)
  12634. When @code{cache} is true, this is the maximum size in bytes of a store
  12635. item for which @command{guix publish} may bypass its cache in case of a
  12636. cache miss. @xref{Invoking guix publish,
  12637. @option{--cache-bypass-threshold}}, for more information.
  12638. @item @code{ttl} (default: @code{#f})
  12639. When it is an integer, this denotes the @dfn{time-to-live} in seconds
  12640. of the published archives. @xref{Invoking guix publish, @option{--ttl}},
  12641. for more information.
  12642. @end table
  12643. @end deftp
  12644. @anchor{rngd-service}
  12645. @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
  12646. [#:device "/dev/hwrng"]
  12647. Return a service that runs the @command{rngd} program from @var{rng-tools}
  12648. to add @var{device} to the kernel's entropy pool. The service will fail if
  12649. @var{device} does not exist.
  12650. @end deffn
  12651. @anchor{pam-limits-service}
  12652. @cindex session limits
  12653. @cindex ulimit
  12654. @cindex priority
  12655. @cindex realtime
  12656. @cindex jackd
  12657. @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
  12658. Return a service that installs a configuration file for the
  12659. @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
  12660. @code{pam_limits} module}. The procedure optionally takes a list of
  12661. @code{pam-limits-entry} values, which can be used to specify
  12662. @code{ulimit} limits and nice priority limits to user sessions.
  12663. The following limits definition sets two hard and soft limits for all
  12664. login sessions of users in the @code{realtime} group:
  12665. @lisp
  12666. (pam-limits-service
  12667. (list
  12668. (pam-limits-entry "@@realtime" 'both 'rtprio 99)
  12669. (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
  12670. @end lisp
  12671. The first entry increases the maximum realtime priority for
  12672. non-privileged processes; the second entry lifts any restriction of the
  12673. maximum address space that can be locked in memory. These settings are
  12674. commonly used for real-time audio systems.
  12675. @end deffn
  12676. @node Scheduled Job Execution
  12677. @subsection Scheduled Job Execution
  12678. @cindex cron
  12679. @cindex mcron
  12680. @cindex scheduling jobs
  12681. The @code{(gnu services mcron)} module provides an interface to
  12682. GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
  12683. mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
  12684. Unix @command{cron} daemon; the main difference is that it is
  12685. implemented in Guile Scheme, which provides a lot of flexibility when
  12686. specifying the scheduling of jobs and their actions.
  12687. The example below defines an operating system that runs the
  12688. @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
  12689. and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
  12690. well as the @command{mkid} command on behalf of an unprivileged user
  12691. (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
  12692. gexps to introduce job definitions that are passed to mcron
  12693. (@pxref{G-Expressions}).
  12694. @lisp
  12695. (use-modules (guix) (gnu) (gnu services mcron))
  12696. (use-package-modules base idutils)
  12697. (define updatedb-job
  12698. ;; Run 'updatedb' at 3AM every day. Here we write the
  12699. ;; job's action as a Scheme procedure.
  12700. #~(job '(next-hour '(3))
  12701. (lambda ()
  12702. (execl (string-append #$findutils "/bin/updatedb")
  12703. "updatedb"
  12704. "--prunepaths=/tmp /var/tmp /gnu/store"))))
  12705. (define garbage-collector-job
  12706. ;; Collect garbage 5 minutes after midnight every day.
  12707. ;; The job's action is a shell command.
  12708. #~(job "5 0 * * *" ;Vixie cron syntax
  12709. "guix gc -F 1G"))
  12710. (define idutils-job
  12711. ;; Update the index database as user "charlie" at 12:15PM
  12712. ;; and 19:15PM. This runs from the user's home directory.
  12713. #~(job '(next-minute-from (next-hour '(12 19)) '(15))
  12714. (string-append #$idutils "/bin/mkid src")
  12715. #:user "charlie"))
  12716. (operating-system
  12717. ;; @dots{}
  12718. ;; %BASE-SERVICES already includes an instance of
  12719. ;; 'mcron-service-type', which we extend with additional
  12720. ;; jobs using 'simple-service'.
  12721. (services (cons (simple-service 'my-cron-jobs
  12722. mcron-service-type
  12723. (list garbage-collector-job
  12724. updatedb-job
  12725. idutils-job))
  12726. %base-services)))
  12727. @end lisp
  12728. For more complex jobs defined in Scheme where you need control over the top
  12729. level, for instance to introduce a @code{use-modules} form, you can move your
  12730. code to a separate program using the @code{program-file} procedure of the
  12731. @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
  12732. illustrates that.
  12733. @lisp
  12734. (define %battery-alert-job
  12735. ;; Beep when the battery percentage falls below %MIN-LEVEL.
  12736. #~(job
  12737. '(next-minute (range 0 60 1))
  12738. #$(program-file
  12739. "battery-alert.scm"
  12740. (with-imported-modules (source-module-closure
  12741. '((guix build utils)))
  12742. #~(begin
  12743. (use-modules (guix build utils)
  12744. (ice-9 popen)
  12745. (ice-9 regex)
  12746. (ice-9 textual-ports)
  12747. (srfi srfi-2))
  12748. (define %min-level 20)
  12749. (setenv "LC_ALL" "C") ;ensure English output
  12750. (and-let* ((input-pipe (open-pipe*
  12751. OPEN_READ
  12752. #$(file-append acpi "/bin/acpi")))
  12753. (output (get-string-all input-pipe))
  12754. (m (string-match "Discharging, ([0-9]+)%" output))
  12755. (level (string->number (match:substring m 1)))
  12756. ((< level %min-level)))
  12757. (format #t "warning: Battery level is low (~a%)~%" level)
  12758. (invoke #$(file-append beep "/bin/beep") "-r5")))))))
  12759. @end lisp
  12760. @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
  12761. for more information on mcron job specifications. Below is the
  12762. reference of the mcron service.
  12763. On a running system, you can use the @code{schedule} action of the service to
  12764. visualize the mcron jobs that will be executed next:
  12765. @example
  12766. # herd schedule mcron
  12767. @end example
  12768. @noindent
  12769. The example above lists the next five tasks that will be executed, but you can
  12770. also specify the number of tasks to display:
  12771. @example
  12772. # herd schedule mcron 10
  12773. @end example
  12774. @defvr {Scheme Variable} mcron-service-type
  12775. This is the type of the @code{mcron} service, whose value is an
  12776. @code{mcron-configuration} object.
  12777. This service type can be the target of a service extension that provides
  12778. it additional job specifications (@pxref{Service Composition}). In
  12779. other words, it is possible to define services that provide additional
  12780. mcron jobs to run.
  12781. @end defvr
  12782. @deftp {Data Type} mcron-configuration
  12783. Data type representing the configuration of mcron.
  12784. @table @asis
  12785. @item @code{mcron} (default: @var{mcron})
  12786. The mcron package to use.
  12787. @item @code{jobs}
  12788. This is a list of gexps (@pxref{G-Expressions}), where each gexp
  12789. corresponds to an mcron job specification (@pxref{Syntax, mcron job
  12790. specifications,, mcron, GNU@tie{}mcron}).
  12791. @end table
  12792. @end deftp
  12793. @node Log Rotation
  12794. @subsection Log Rotation
  12795. @cindex rottlog
  12796. @cindex log rotation
  12797. @cindex logging
  12798. Log files such as those found in @file{/var/log} tend to grow endlessly,
  12799. so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
  12800. their contents in separate files, possibly compressed. The @code{(gnu
  12801. services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
  12802. log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
  12803. This service is part of @code{%base-services}, and thus enabled by
  12804. default, with the default settings, for commonly encountered log files.
  12805. The example below shows how to extend it with an additional
  12806. @dfn{rotation}, should you need to do that (usually, services that
  12807. produce log files already take care of that):
  12808. @lisp
  12809. (use-modules (guix) (gnu))
  12810. (use-service-modules admin)
  12811. (define my-log-files
  12812. ;; Log files that I want to rotate.
  12813. '("/var/log/something.log" "/var/log/another.log"))
  12814. (operating-system
  12815. ;; @dots{}
  12816. (services (cons (simple-service 'rotate-my-stuff
  12817. rottlog-service-type
  12818. (list (log-rotation
  12819. (frequency 'daily)
  12820. (files my-log-files))))
  12821. %base-services)))
  12822. @end lisp
  12823. @defvr {Scheme Variable} rottlog-service-type
  12824. This is the type of the Rottlog service, whose value is a
  12825. @code{rottlog-configuration} object.
  12826. Other services can extend this one with new @code{log-rotation} objects
  12827. (see below), thereby augmenting the set of files to be rotated.
  12828. This service type can define mcron jobs (@pxref{Scheduled Job
  12829. Execution}) to run the rottlog service.
  12830. @end defvr
  12831. @deftp {Data Type} rottlog-configuration
  12832. Data type representing the configuration of rottlog.
  12833. @table @asis
  12834. @item @code{rottlog} (default: @code{rottlog})
  12835. The Rottlog package to use.
  12836. @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
  12837. The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
  12838. rottlog, GNU Rot[t]log Manual}).
  12839. @item @code{rotations} (default: @code{%default-rotations})
  12840. A list of @code{log-rotation} objects as defined below.
  12841. @item @code{jobs}
  12842. This is a list of gexps where each gexp corresponds to an mcron job
  12843. specification (@pxref{Scheduled Job Execution}).
  12844. @end table
  12845. @end deftp
  12846. @deftp {Data Type} log-rotation
  12847. Data type representing the rotation of a group of log files.
  12848. Taking an example from the Rottlog manual (@pxref{Period Related File
  12849. Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
  12850. defined like this:
  12851. @lisp
  12852. (log-rotation
  12853. (frequency 'daily)
  12854. (files '("/var/log/apache/*"))
  12855. (options '("storedir apache-archives"
  12856. "rotate 6"
  12857. "notifempty"
  12858. "nocompress")))
  12859. @end lisp
  12860. The list of fields is as follows:
  12861. @table @asis
  12862. @item @code{frequency} (default: @code{'weekly})
  12863. The log rotation frequency, a symbol.
  12864. @item @code{files}
  12865. The list of files or file glob patterns to rotate.
  12866. @item @code{options} (default: @code{'()})
  12867. The list of rottlog options for this rotation (@pxref{Configuration
  12868. parameters,,, rottlog, GNU Rot[t]lg Manual}).
  12869. @item @code{post-rotate} (default: @code{#f})
  12870. Either @code{#f} or a gexp to execute once the rotation has completed.
  12871. @end table
  12872. @end deftp
  12873. @defvr {Scheme Variable} %default-rotations
  12874. Specifies weekly rotation of @code{%rotated-files} and of
  12875. @file{/var/log/guix-daemon.log}.
  12876. @end defvr
  12877. @defvr {Scheme Variable} %rotated-files
  12878. The list of syslog-controlled files to be rotated. By default it is:
  12879. @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
  12880. "/var/log/maillog")}.
  12881. @end defvr
  12882. @node Networking Services
  12883. @subsection Networking Services
  12884. The @code{(gnu services networking)} module provides services to configure
  12885. the network interface.
  12886. @cindex DHCP, networking service
  12887. @defvr {Scheme Variable} dhcp-client-service-type
  12888. This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
  12889. Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
  12890. is the DHCP client package to use, @code{isc-dhcp} by default.
  12891. @end defvr
  12892. @deffn {Scheme Procedure} dhcpd-service-type
  12893. This type defines a service that runs a DHCP daemon. To create a
  12894. service of this type, you must supply a @code{<dhcpd-configuration>}.
  12895. For example:
  12896. @lisp
  12897. (service dhcpd-service-type
  12898. (dhcpd-configuration
  12899. (config-file (local-file "my-dhcpd.conf"))
  12900. (interfaces '("enp0s25"))))
  12901. @end lisp
  12902. @end deffn
  12903. @deftp {Data Type} dhcpd-configuration
  12904. @table @asis
  12905. @item @code{package} (default: @code{isc-dhcp})
  12906. The package that provides the DHCP daemon. This package is expected to
  12907. provide the daemon at @file{sbin/dhcpd} relative to its output
  12908. directory. The default package is the
  12909. @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
  12910. @item @code{config-file} (default: @code{#f})
  12911. The configuration file to use. This is required. It will be passed to
  12912. @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
  12913. object (@pxref{G-Expressions, file-like objects}). See @code{man
  12914. dhcpd.conf} for details on the configuration file syntax.
  12915. @item @code{version} (default: @code{"4"})
  12916. The DHCP version to use. The ISC DHCP server supports the values ``4'',
  12917. ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
  12918. options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
  12919. details.
  12920. @item @code{run-directory} (default: @code{"/run/dhcpd"})
  12921. The run directory to use. At service activation time, this directory
  12922. will be created if it does not exist.
  12923. @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
  12924. The PID file to use. This corresponds to the @code{-pf} option of
  12925. @code{dhcpd}. See @code{man dhcpd} for details.
  12926. @item @code{interfaces} (default: @code{'()})
  12927. The names of the network interfaces on which dhcpd should listen for
  12928. broadcasts. If this list is not empty, then its elements (which must be
  12929. strings) will be appended to the @code{dhcpd} invocation when starting
  12930. the daemon. It may not be necessary to explicitly specify any
  12931. interfaces here; see @code{man dhcpd} for details.
  12932. @end table
  12933. @end deftp
  12934. @defvr {Scheme Variable} static-networking-service-type
  12935. This is the type for statically-configured network interfaces.
  12936. @c TODO Document <static-networking> data structures.
  12937. @end defvr
  12938. @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
  12939. [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
  12940. [#:requirement @code{'(udev)}]
  12941. Return a service that starts @var{interface} with address @var{ip}. If
  12942. @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
  12943. it must be a string specifying the default network gateway. @var{requirement}
  12944. can be used to declare a dependency on another service before configuring the
  12945. interface.
  12946. This procedure can be called several times, one for each network
  12947. interface of interest. Behind the scenes what it does is extend
  12948. @code{static-networking-service-type} with additional network interfaces
  12949. to handle.
  12950. For example:
  12951. @lisp
  12952. (static-networking-service "eno1" "192.168.1.82"
  12953. #:gateway "192.168.1.2"
  12954. #:name-servers '("192.168.1.2"))
  12955. @end lisp
  12956. @end deffn
  12957. @cindex wicd
  12958. @cindex wireless
  12959. @cindex WiFi
  12960. @cindex network management
  12961. @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
  12962. Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
  12963. management daemon that aims to simplify wired and wireless networking.
  12964. This service adds the @var{wicd} package to the global profile, providing
  12965. several commands to interact with the daemon and configure networking:
  12966. @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
  12967. and @command{wicd-curses} user interfaces.
  12968. @end deffn
  12969. @cindex ModemManager
  12970. @defvr {Scheme Variable} modem-manager-service-type
  12971. This is the service type for the
  12972. @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
  12973. service. The value for this service type is a
  12974. @code{modem-manager-configuration} record.
  12975. This service is part of @code{%desktop-services} (@pxref{Desktop
  12976. Services}).
  12977. @end defvr
  12978. @deftp {Data Type} modem-manager-configuration
  12979. Data type representing the configuration of ModemManager.
  12980. @table @asis
  12981. @item @code{modem-manager} (default: @code{modem-manager})
  12982. The ModemManager package to use.
  12983. @end table
  12984. @end deftp
  12985. @cindex USB_ModeSwitch
  12986. @cindex Modeswitching
  12987. @defvr {Scheme Variable} usb-modeswitch-service-type
  12988. This is the service type for the
  12989. @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
  12990. service. The value for this service type is
  12991. a @code{usb-modeswitch-configuration} record.
  12992. When plugged in, some USB modems (and other USB devices) initially present
  12993. themselves as a read-only storage medium and not as a modem. They need to be
  12994. @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
  12995. installs udev rules to automatically modeswitch these devices when they are
  12996. plugged in.
  12997. This service is part of @code{%desktop-services} (@pxref{Desktop
  12998. Services}).
  12999. @end defvr
  13000. @deftp {Data Type} usb-modeswitch-configuration
  13001. Data type representing the configuration of USB_ModeSwitch.
  13002. @table @asis
  13003. @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
  13004. The USB_ModeSwitch package providing the binaries for modeswitching.
  13005. @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
  13006. The package providing the device data and udev rules file used by
  13007. USB_ModeSwitch.
  13008. @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
  13009. Which config file to use for the USB_ModeSwitch dispatcher. By default the
  13010. config file shipped with USB_ModeSwitch is used which disables logging to
  13011. @file{/var/log} among other default settings. If set to @code{#f}, no config
  13012. file is used.
  13013. @end table
  13014. @end deftp
  13015. @cindex NetworkManager
  13016. @defvr {Scheme Variable} network-manager-service-type
  13017. This is the service type for the
  13018. @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
  13019. service. The value for this service type is a
  13020. @code{network-manager-configuration} record.
  13021. This service is part of @code{%desktop-services} (@pxref{Desktop
  13022. Services}).
  13023. @end defvr
  13024. @deftp {Data Type} network-manager-configuration
  13025. Data type representing the configuration of NetworkManager.
  13026. @table @asis
  13027. @item @code{network-manager} (default: @code{network-manager})
  13028. The NetworkManager package to use.
  13029. @item @code{dns} (default: @code{"default"})
  13030. Processing mode for DNS, which affects how NetworkManager uses the
  13031. @code{resolv.conf} configuration file.
  13032. @table @samp
  13033. @item default
  13034. NetworkManager will update @code{resolv.conf} to reflect the nameservers
  13035. provided by currently active connections.
  13036. @item dnsmasq
  13037. NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
  13038. @dfn{conditional forwarding} configuration if you are connected to a VPN, and
  13039. then update @code{resolv.conf} to point to the local nameserver.
  13040. With this setting, you can share your network connection. For example when
  13041. you want to share your network connection to another laptop @i{via} an
  13042. Ethernet cable, you can open @command{nm-connection-editor} and configure the
  13043. Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
  13044. and reestablish the connection (or reboot).
  13045. You can also set up a @dfn{host-to-guest connection} to QEMU VMs
  13046. (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
  13047. e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
  13048. browser on your host system, or connect to the VM @i{via} SSH
  13049. (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
  13050. host-to-guest connection, run this command once:
  13051. @example
  13052. nmcli connection add type tun \
  13053. connection.interface-name tap0 \
  13054. tun.mode tap tun.owner $(id -u) \
  13055. ipv4.method shared \
  13056. ipv4.addresses 172.28.112.1/24
  13057. @end example
  13058. Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
  13059. @option{-nic tap,ifname=tap0,script=no,downscript=no} to
  13060. @command{qemu-system-...}.
  13061. @item none
  13062. NetworkManager will not modify @code{resolv.conf}.
  13063. @end table
  13064. @item @code{vpn-plugins} (default: @code{'()})
  13065. This is the list of available plugins for virtual private networks
  13066. (VPNs). An example of this is the @code{network-manager-openvpn}
  13067. package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
  13068. @end table
  13069. @end deftp
  13070. @cindex Connman
  13071. @deffn {Scheme Variable} connman-service-type
  13072. This is the service type to run @url{https://01.org/connman,Connman},
  13073. a network connection manager.
  13074. Its value must be an
  13075. @code{connman-configuration} record as in this example:
  13076. @lisp
  13077. (service connman-service-type
  13078. (connman-configuration
  13079. (disable-vpn? #t)))
  13080. @end lisp
  13081. See below for details about @code{connman-configuration}.
  13082. @end deffn
  13083. @deftp {Data Type} connman-configuration
  13084. Data Type representing the configuration of connman.
  13085. @table @asis
  13086. @item @code{connman} (default: @var{connman})
  13087. The connman package to use.
  13088. @item @code{disable-vpn?} (default: @code{#f})
  13089. When true, disable connman's vpn plugin.
  13090. @end table
  13091. @end deftp
  13092. @cindex WPA Supplicant
  13093. @defvr {Scheme Variable} wpa-supplicant-service-type
  13094. This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
  13095. supplicant}, an authentication daemon required to authenticate against
  13096. encrypted WiFi or ethernet networks.
  13097. @end defvr
  13098. @deftp {Data Type} wpa-supplicant-configuration
  13099. Data type representing the configuration of WPA Supplicant.
  13100. It takes the following parameters:
  13101. @table @asis
  13102. @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
  13103. The WPA Supplicant package to use.
  13104. @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
  13105. List of services that should be started before WPA Supplicant starts.
  13106. @item @code{dbus?} (default: @code{#t})
  13107. Whether to listen for requests on D-Bus.
  13108. @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
  13109. Where to store the PID file.
  13110. @item @code{interface} (default: @code{#f})
  13111. If this is set, it must specify the name of a network interface that
  13112. WPA supplicant will control.
  13113. @item @code{config-file} (default: @code{#f})
  13114. Optional configuration file to use.
  13115. @item @code{extra-options} (default: @code{'()})
  13116. List of additional command-line arguments to pass to the daemon.
  13117. @end table
  13118. @end deftp
  13119. @cindex hostapd service, for Wi-Fi access points
  13120. @cindex Wi-Fi access points, hostapd service
  13121. @defvr {Scheme Variable} hostapd-service-type
  13122. This is the service type to run the @uref{https://w1.fi/hostapd/,
  13123. hostapd} daemon to set up WiFi (IEEE 802.11) access points and
  13124. authentication servers. Its associated value must be a
  13125. @code{hostapd-configuration} as shown below:
  13126. @lisp
  13127. ;; Use wlan1 to run the access point for "My Network".
  13128. (service hostapd-service-type
  13129. (hostapd-configuration
  13130. (interface "wlan1")
  13131. (ssid "My Network")
  13132. (channel 12)))
  13133. @end lisp
  13134. @end defvr
  13135. @deftp {Data Type} hostapd-configuration
  13136. This data type represents the configuration of the hostapd service, with
  13137. the following fields:
  13138. @table @asis
  13139. @item @code{package} (default: @code{hostapd})
  13140. The hostapd package to use.
  13141. @item @code{interface} (default: @code{"wlan0"})
  13142. The network interface to run the WiFi access point.
  13143. @item @code{ssid}
  13144. The SSID (@dfn{service set identifier}), a string that identifies this
  13145. network.
  13146. @item @code{broadcast-ssid?} (default: @code{#t})
  13147. Whether to broadcast this SSID.
  13148. @item @code{channel} (default: @code{1})
  13149. The WiFi channel to use.
  13150. @item @code{driver} (default: @code{"nl80211"})
  13151. The driver interface type. @code{"nl80211"} is used with all Linux
  13152. mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
  13153. RADIUS server that does # not control any wireless/wired driver.
  13154. @item @code{extra-settings} (default: @code{""})
  13155. Extra settings to append as-is to the hostapd configuration file. See
  13156. @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
  13157. configuration file reference.
  13158. @end table
  13159. @end deftp
  13160. @defvr {Scheme Variable} simulated-wifi-service-type
  13161. This is the type of a service to simulate WiFi networking, which can be
  13162. useful in virtual machines for testing purposes. The service loads the
  13163. Linux kernel
  13164. @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
  13165. @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
  13166. network that can be seen on @code{wlan0}, by default.
  13167. The service's value is a @code{hostapd-configuration} record.
  13168. @end defvr
  13169. @cindex iptables
  13170. @defvr {Scheme Variable} iptables-service-type
  13171. This is the service type to set up an iptables configuration. iptables is a
  13172. packet filtering framework supported by the Linux kernel. This service
  13173. supports configuring iptables for both IPv4 and IPv6. A simple example
  13174. configuration rejecting all incoming connections except those to the ssh port
  13175. 22 is shown below.
  13176. @lisp
  13177. (service iptables-service-type
  13178. (iptables-configuration
  13179. (ipv4-rules (plain-file "iptables.rules" "*filter
  13180. :INPUT ACCEPT
  13181. :FORWARD ACCEPT
  13182. :OUTPUT ACCEPT
  13183. -A INPUT -p tcp --dport 22 -j ACCEPT
  13184. -A INPUT -j REJECT --reject-with icmp-port-unreachable
  13185. COMMIT
  13186. "))
  13187. (ipv6-rules (plain-file "ip6tables.rules" "*filter
  13188. :INPUT ACCEPT
  13189. :FORWARD ACCEPT
  13190. :OUTPUT ACCEPT
  13191. -A INPUT -p tcp --dport 22 -j ACCEPT
  13192. -A INPUT -j REJECT --reject-with icmp6-port-unreachable
  13193. COMMIT
  13194. "))))
  13195. @end lisp
  13196. @end defvr
  13197. @deftp {Data Type} iptables-configuration
  13198. The data type representing the configuration of iptables.
  13199. @table @asis
  13200. @item @code{iptables} (default: @code{iptables})
  13201. The iptables package that provides @code{iptables-restore} and
  13202. @code{ip6tables-restore}.
  13203. @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
  13204. The iptables rules to use. It will be passed to @code{iptables-restore}.
  13205. This may be any ``file-like'' object (@pxref{G-Expressions, file-like
  13206. objects}).
  13207. @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
  13208. The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
  13209. This may be any ``file-like'' object (@pxref{G-Expressions, file-like
  13210. objects}).
  13211. @end table
  13212. @end deftp
  13213. @cindex nftables
  13214. @defvr {Scheme Variable} nftables-service-type
  13215. This is the service type to set up a nftables configuration. nftables is a
  13216. netfilter project that aims to replace the existing iptables, ip6tables,
  13217. arptables and ebtables framework. It provides a new packet filtering
  13218. framework, a new user-space utility @command{nft}, and a compatibility layer
  13219. for iptables. This service comes with a default ruleset
  13220. @code{%default-nftables-ruleset} that rejecting all incomming connections
  13221. except those to the ssh port 22. To use it, simply write:
  13222. @lisp
  13223. (service nftables-service-type)
  13224. @end lisp
  13225. @end defvr
  13226. @deftp {Data Type} nftables-configuration
  13227. The data type representing the configuration of nftables.
  13228. @table @asis
  13229. @item @code{package} (default: @code{nftables})
  13230. The nftables package that provides @command{nft}.
  13231. @item @code{ruleset} (default: @code{%default-nftables-ruleset})
  13232. The nftables ruleset to use. This may be any ``file-like'' object
  13233. (@pxref{G-Expressions, file-like objects}).
  13234. @end table
  13235. @end deftp
  13236. @cindex NTP (Network Time Protocol), service
  13237. @cindex ntpd, service for the Network Time Protocol daemon
  13238. @cindex real time clock
  13239. @defvr {Scheme Variable} ntp-service-type
  13240. This is the type of the service running the @uref{https://www.ntp.org,
  13241. Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
  13242. system clock synchronized with that of the specified NTP servers.
  13243. The value of this service is an @code{ntpd-configuration} object, as described
  13244. below.
  13245. @end defvr
  13246. @deftp {Data Type} ntp-configuration
  13247. This is the data type for the NTP service configuration.
  13248. @table @asis
  13249. @item @code{servers} (default: @code{%ntp-servers})
  13250. This is the list of servers (@code{<ntp-server>} records) with which
  13251. @command{ntpd} will be synchronized. See the @code{ntp-server} data type
  13252. definition below.
  13253. @item @code{allow-large-adjustment?} (default: @code{#t})
  13254. This determines whether @command{ntpd} is allowed to make an initial
  13255. adjustment of more than 1,000 seconds.
  13256. @item @code{ntp} (default: @code{ntp})
  13257. The NTP package to use.
  13258. @end table
  13259. @end deftp
  13260. @defvr {Scheme Variable} %ntp-servers
  13261. List of host names used as the default NTP servers. These are servers of the
  13262. @uref{https://www.ntppool.org/en/, NTP Pool Project}.
  13263. @end defvr
  13264. @deftp {Data Type} ntp-server
  13265. The data type representing the configuration of a NTP server.
  13266. @table @asis
  13267. @item @code{type} (default: @code{'server})
  13268. The type of the NTP server, given as a symbol. One of @code{'pool},
  13269. @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
  13270. @item @code{address}
  13271. The address of the server, as a string.
  13272. @item @code{options}
  13273. NTPD options to use with that specific server, given as a list of option names
  13274. and/or of option names and values tuples. The following example define a server
  13275. to use with the options @option{iburst} and @option{prefer}, as well as
  13276. @option{version} 3 and a @option{maxpoll} time of 16 seconds.
  13277. @example
  13278. (ntp-server
  13279. (type 'server)
  13280. (address "some.ntp.server.org")
  13281. (options `(iburst (version 3) (maxpoll 16) prefer))))
  13282. @end example
  13283. @end table
  13284. @end deftp
  13285. @cindex OpenNTPD
  13286. @deffn {Scheme Procedure} openntpd-service-type
  13287. Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
  13288. by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
  13289. clock synchronized with that of the given servers.
  13290. @lisp
  13291. (service
  13292. openntpd-service-type
  13293. (openntpd-configuration
  13294. (listen-on '("127.0.0.1" "::1"))
  13295. (sensor '("udcf0 correction 70000"))
  13296. (constraint-from '("www.gnu.org"))
  13297. (constraints-from '("https://www.google.com/"))))
  13298. @end lisp
  13299. @end deffn
  13300. @defvr {Scheme Variable} %openntpd-servers
  13301. This variable is a list of the server addresses defined in
  13302. @code{%ntp-servers}.
  13303. @end defvr
  13304. @deftp {Data Type} openntpd-configuration
  13305. @table @asis
  13306. @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
  13307. The openntpd executable to use.
  13308. @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
  13309. A list of local IP addresses or hostnames the ntpd daemon should listen on.
  13310. @item @code{query-from} (default: @code{'()})
  13311. A list of local IP address the ntpd daemon should use for outgoing queries.
  13312. @item @code{sensor} (default: @code{'()})
  13313. Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
  13314. will listen to each sensor that actually exists and ignore non-existent ones.
  13315. See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
  13316. information.
  13317. @item @code{server} (default: @code{'()})
  13318. Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
  13319. @item @code{servers} (default: @code{%openntp-servers})
  13320. Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
  13321. @item @code{constraint-from} (default: @code{'()})
  13322. @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
  13323. This time information is not used for precision but acts as an authenticated
  13324. constraint, thereby reducing the impact of unauthenticated NTP
  13325. man-in-the-middle attacks.
  13326. Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
  13327. a constraint.
  13328. @item @code{constraints-from} (default: @code{'()})
  13329. As with constraint from, specify a list of URLs, IP addresses or hostnames of
  13330. HTTPS servers to provide a constraint. Should the hostname resolve to multiple
  13331. IP addresses, @code{ntpd} will calculate a median constraint from all of them.
  13332. @end table
  13333. @end deftp
  13334. @cindex inetd
  13335. @deffn {Scheme variable} inetd-service-type
  13336. This service runs the @command{inetd} (@pxref{inetd invocation,,,
  13337. inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
  13338. connections on internet sockets, and lazily starts the specified server
  13339. program when a connection is made on one of these sockets.
  13340. The value of this service is an @code{inetd-configuration} object. The
  13341. following example configures the @command{inetd} daemon to provide the
  13342. built-in @command{echo} service, as well as an smtp service which
  13343. forwards smtp traffic over ssh to a server @code{smtp-server} behind a
  13344. gateway @code{hostname}:
  13345. @lisp
  13346. (service
  13347. inetd-service-type
  13348. (inetd-configuration
  13349. (entries (list
  13350. (inetd-entry
  13351. (name "echo")
  13352. (socket-type 'stream)
  13353. (protocol "tcp")
  13354. (wait? #f)
  13355. (user "root"))
  13356. (inetd-entry
  13357. (node "127.0.0.1")
  13358. (name "smtp")
  13359. (socket-type 'stream)
  13360. (protocol "tcp")
  13361. (wait? #f)
  13362. (user "root")
  13363. (program (file-append openssh "/bin/ssh"))
  13364. (arguments
  13365. '("ssh" "-qT" "-i" "/path/to/ssh_key"
  13366. "-W" "smtp-server:25" "user@@hostname")))))))
  13367. @end lisp
  13368. See below for more details about @code{inetd-configuration}.
  13369. @end deffn
  13370. @deftp {Data Type} inetd-configuration
  13371. Data type representing the configuration of @command{inetd}.
  13372. @table @asis
  13373. @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
  13374. The @command{inetd} executable to use.
  13375. @item @code{entries} (default: @code{'()})
  13376. A list of @command{inetd} service entries. Each entry should be created
  13377. by the @code{inetd-entry} constructor.
  13378. @end table
  13379. @end deftp
  13380. @deftp {Data Type} inetd-entry
  13381. Data type representing an entry in the @command{inetd} configuration.
  13382. Each entry corresponds to a socket where @command{inetd} will listen for
  13383. requests.
  13384. @table @asis
  13385. @item @code{node} (default: @code{#f})
  13386. Optional string, a comma-separated list of local addresses
  13387. @command{inetd} should use when listening for this service.
  13388. @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
  13389. description of all options.
  13390. @item @code{name}
  13391. A string, the name must correspond to an entry in @code{/etc/services}.
  13392. @item @code{socket-type}
  13393. One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
  13394. @code{'seqpacket}.
  13395. @item @code{protocol}
  13396. A string, must correspond to an entry in @code{/etc/protocols}.
  13397. @item @code{wait?} (default: @code{#t})
  13398. Whether @command{inetd} should wait for the server to exit before
  13399. listening to new service requests.
  13400. @item @code{user}
  13401. A string containing the user (and, optionally, group) name of the user
  13402. as whom the server should run. The group name can be specified in a
  13403. suffix, separated by a colon or period, i.e.@: @code{"user"},
  13404. @code{"user:group"} or @code{"user.group"}.
  13405. @item @code{program} (default: @code{"internal"})
  13406. The server program which will serve the requests, or @code{"internal"}
  13407. if @command{inetd} should use a built-in service.
  13408. @item @code{arguments} (default: @code{'()})
  13409. A list strings or file-like objects, which are the server program's
  13410. arguments, starting with the zeroth argument, i.e.@: the name of the
  13411. program itself. For @command{inetd}'s internal services, this entry
  13412. must be @code{'()} or @code{'("internal")}.
  13413. @end table
  13414. @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
  13415. detailed discussion of each configuration field.
  13416. @end deftp
  13417. @cindex Tor
  13418. @defvr {Scheme Variable} tor-service-type
  13419. This is the type for a service that runs the @uref{https://torproject.org,
  13420. Tor} anonymous networking daemon. The service is configured using a
  13421. @code{<tor-configuration>} record. By default, the Tor daemon runs as the
  13422. @code{tor} unprivileged user, which is a member of the @code{tor} group.
  13423. @end defvr
  13424. @deftp {Data Type} tor-configuration
  13425. @table @asis
  13426. @item @code{tor} (default: @code{tor})
  13427. The package that provides the Tor daemon. This package is expected to provide
  13428. the daemon at @file{bin/tor} relative to its output directory. The default
  13429. package is the @uref{https://www.torproject.org, Tor Project's}
  13430. implementation.
  13431. @item @code{config-file} (default: @code{(plain-file "empty" "")})
  13432. The configuration file to use. It will be appended to a default configuration
  13433. file, and the final configuration file will be passed to @code{tor} via its
  13434. @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
  13435. file-like objects}). See @code{man tor} for details on the configuration file
  13436. syntax.
  13437. @item @code{hidden-services} (default: @code{'()})
  13438. The list of @code{<hidden-service>} records to use. For any hidden service
  13439. you include in this list, appropriate configuration to enable the hidden
  13440. service will be automatically added to the default configuration file. You
  13441. may conveniently create @code{<hidden-service>} records using the
  13442. @code{tor-hidden-service} procedure described below.
  13443. @item @code{socks-socket-type} (default: @code{'tcp})
  13444. The default socket type that Tor should use for its SOCKS socket. This must
  13445. be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
  13446. Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
  13447. If it is @code{'unix}, then Tor will listen on the UNIX domain socket
  13448. @file{/var/run/tor/socks-sock}, which will be made writable by members of the
  13449. @code{tor} group.
  13450. If you want to customize the SOCKS socket in more detail, leave
  13451. @code{socks-socket-type} at its default value of @code{'tcp} and use
  13452. @code{config-file} to override the default by providing your own
  13453. @code{SocksPort} option.
  13454. @end table
  13455. @end deftp
  13456. @cindex hidden service
  13457. @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
  13458. Define a new Tor @dfn{hidden service} called @var{name} and implementing
  13459. @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
  13460. @example
  13461. '((22 "127.0.0.1:22")
  13462. (80 "127.0.0.1:8080"))
  13463. @end example
  13464. In this example, port 22 of the hidden service is mapped to local port 22, and
  13465. port 80 is mapped to local port 8080.
  13466. This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
  13467. the @file{hostname} file contains the @code{.onion} host name for the hidden
  13468. service.
  13469. See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
  13470. project's documentation} for more information.
  13471. @end deffn
  13472. The @code{(gnu services rsync)} module provides the following services:
  13473. You might want an rsync daemon if you have files that you want available
  13474. so anyone (or just yourself) can download existing files or upload new
  13475. files.
  13476. @deffn {Scheme Variable} rsync-service-type
  13477. This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
  13478. The value for this service type is a
  13479. @command{rsync-configuration} record as in this example:
  13480. @lisp
  13481. (service rsync-service-type)
  13482. @end lisp
  13483. See below for details about @code{rsync-configuration}.
  13484. @end deffn
  13485. @deftp {Data Type} rsync-configuration
  13486. Data type representing the configuration for @code{rsync-service}.
  13487. @table @asis
  13488. @item @code{package} (default: @var{rsync})
  13489. @code{rsync} package to use.
  13490. @item @code{port-number} (default: @code{873})
  13491. TCP port on which @command{rsync} listens for incoming connections. If port
  13492. is less than @code{1024} @command{rsync} needs to be started as the
  13493. @code{root} user and group.
  13494. @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
  13495. Name of the file where @command{rsync} writes its PID.
  13496. @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
  13497. Name of the file where @command{rsync} writes its lock file.
  13498. @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
  13499. Name of the file where @command{rsync} writes its log file.
  13500. @item @code{use-chroot?} (default: @var{#t})
  13501. Whether to use chroot for @command{rsync} shared directory.
  13502. @item @code{share-path} (default: @file{/srv/rsync})
  13503. Location of the @command{rsync} shared directory.
  13504. @item @code{share-comment} (default: @code{"Rsync share"})
  13505. Comment of the @command{rsync} shared directory.
  13506. @item @code{read-only?} (default: @var{#f})
  13507. Read-write permissions to shared directory.
  13508. @item @code{timeout} (default: @code{300})
  13509. I/O timeout in seconds.
  13510. @item @code{user} (default: @var{"root"})
  13511. Owner of the @code{rsync} process.
  13512. @item @code{group} (default: @var{"root"})
  13513. Group of the @code{rsync} process.
  13514. @item @code{uid} (default: @var{"rsyncd"})
  13515. User name or user ID that file transfers to and from that module should take
  13516. place as when the daemon was run as @code{root}.
  13517. @item @code{gid} (default: @var{"rsyncd"})
  13518. Group name or group ID that will be used when accessing the module.
  13519. @end table
  13520. @end deftp
  13521. The @code{(gnu services syncthing)} module provides the following services:
  13522. @cindex syncthing
  13523. You might want a syncthing daemon if you have files between two or more
  13524. computers and want to sync them in real time, safely protected from
  13525. prying eyes.
  13526. @deffn {Scheme Variable} syncthing-service-type
  13527. This is the service type for the @uref{https://syncthing.net/,
  13528. syncthing} daemon, The value for this service type is a
  13529. @command{syncthing-configuration} record as in this example:
  13530. @lisp
  13531. (service syncthing-service-type
  13532. (syncthing-configuration (user "alice")))
  13533. @end lisp
  13534. See below for details about @code{syncthing-configuration}.
  13535. @deftp {Data Type} syncthing-configuration
  13536. Data type representing the configuration for @code{syncthing-service-type}.
  13537. @table @asis
  13538. @item @code{syncthing} (default: @var{syncthing})
  13539. @code{syncthing} package to use.
  13540. @item @code{arguments} (default: @var{'()})
  13541. List of command-line arguments passing to @code{syncthing} binary.
  13542. @item @code{logflags} (default: @var{0})
  13543. Sum of loging flags, see
  13544. @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
  13545. @item @code{user} (default: @var{#f})
  13546. The user as which the Syncthing service is to be run.
  13547. This assumes that the specified user exists.
  13548. @item @code{group} (default: @var{"users"})
  13549. The group as which the Syncthing service is to be run.
  13550. This assumes that the specified group exists.
  13551. @item @code{home} (default: @var{#f})
  13552. Common configuration and data directory. The default configuration
  13553. directory is @file{$HOME} of the specified Syncthing @code{user}.
  13554. @end table
  13555. @end deftp
  13556. @end deffn
  13557. Furthermore, @code{(gnu services ssh)} provides the following services.
  13558. @cindex SSH
  13559. @cindex SSH server
  13560. @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
  13561. [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
  13562. [#:allow-empty-passwords? #f] [#:root-login? #f] @
  13563. [#:syslog-output? #t] [#:x11-forwarding? #t] @
  13564. [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
  13565. [#:public-key-authentication? #t] [#:initialize? #t]
  13566. Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
  13567. @var{host-key} must designate a file containing the host key, and readable
  13568. only by root.
  13569. When @var{daemonic?} is true, @command{lshd} will detach from the
  13570. controlling terminal and log its output to syslogd, unless one sets
  13571. @var{syslog-output?} to false. Obviously, it also makes lsh-service
  13572. depend on existence of syslogd service. When @var{pid-file?} is true,
  13573. @command{lshd} writes its PID to the file called @var{pid-file}.
  13574. When @var{initialize?} is true, automatically create the seed and host key
  13575. upon service activation if they do not exist yet. This may take long and
  13576. require interaction.
  13577. When @var{initialize?} is false, it is up to the user to initialize the
  13578. randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
  13579. a key pair with the private key stored in file @var{host-key} (@pxref{lshd
  13580. basics,,, lsh, LSH Manual}).
  13581. When @var{interfaces} is empty, lshd listens for connections on all the
  13582. network interfaces; otherwise, @var{interfaces} must be a list of host names
  13583. or addresses.
  13584. @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
  13585. passwords, and @var{root-login?} specifies whether to accept log-ins as
  13586. root.
  13587. The other options should be self-descriptive.
  13588. @end deffn
  13589. @cindex SSH
  13590. @cindex SSH server
  13591. @deffn {Scheme Variable} openssh-service-type
  13592. This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
  13593. shell daemon, @command{sshd}. Its value must be an
  13594. @code{openssh-configuration} record as in this example:
  13595. @lisp
  13596. (service openssh-service-type
  13597. (openssh-configuration
  13598. (x11-forwarding? #t)
  13599. (permit-root-login 'without-password)
  13600. (authorized-keys
  13601. `(("alice" ,(local-file "alice.pub"))
  13602. ("bob" ,(local-file "bob.pub"))))))
  13603. @end lisp
  13604. See below for details about @code{openssh-configuration}.
  13605. This service can be extended with extra authorized keys, as in this
  13606. example:
  13607. @lisp
  13608. (service-extension openssh-service-type
  13609. (const `(("charlie"
  13610. ,(local-file "charlie.pub")))))
  13611. @end lisp
  13612. @end deffn
  13613. @deftp {Data Type} openssh-configuration
  13614. This is the configuration record for OpenSSH's @command{sshd}.
  13615. @table @asis
  13616. @item @code{openssh} (default @var{openssh})
  13617. The Openssh package to use.
  13618. @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
  13619. Name of the file where @command{sshd} writes its PID.
  13620. @item @code{port-number} (default: @code{22})
  13621. TCP port on which @command{sshd} listens for incoming connections.
  13622. @item @code{permit-root-login} (default: @code{#f})
  13623. This field determines whether and when to allow logins as root. If
  13624. @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
  13625. If it's the symbol @code{'without-password}, then root logins are
  13626. permitted but not with password-based authentication.
  13627. @item @code{allow-empty-passwords?} (default: @code{#f})
  13628. When true, users with empty passwords may log in. When false, they may
  13629. not.
  13630. @item @code{password-authentication?} (default: @code{#t})
  13631. When true, users may log in with their password. When false, they have
  13632. other authentication methods.
  13633. @item @code{public-key-authentication?} (default: @code{#t})
  13634. When true, users may log in using public key authentication. When
  13635. false, users have to use other authentication method.
  13636. Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
  13637. This is used only by protocol version 2.
  13638. @item @code{x11-forwarding?} (default: @code{#f})
  13639. When true, forwarding of X11 graphical client connections is
  13640. enabled---in other words, @command{ssh} options @option{-X} and
  13641. @option{-Y} will work.
  13642. @item @code{allow-agent-forwarding?} (default: @code{#t})
  13643. Whether to allow agent forwarding.
  13644. @item @code{allow-tcp-forwarding?} (default: @code{#t})
  13645. Whether to allow TCP forwarding.
  13646. @item @code{gateway-ports?} (default: @code{#f})
  13647. Whether to allow gateway ports.
  13648. @item @code{challenge-response-authentication?} (default: @code{#f})
  13649. Specifies whether challenge response authentication is allowed (e.g.@: via
  13650. PAM).
  13651. @item @code{use-pam?} (default: @code{#t})
  13652. Enables the Pluggable Authentication Module interface. If set to
  13653. @code{#t}, this will enable PAM authentication using
  13654. @code{challenge-response-authentication?} and
  13655. @code{password-authentication?}, in addition to PAM account and session
  13656. module processing for all authentication types.
  13657. Because PAM challenge response authentication usually serves an
  13658. equivalent role to password authentication, you should disable either
  13659. @code{challenge-response-authentication?} or
  13660. @code{password-authentication?}.
  13661. @item @code{print-last-log?} (default: @code{#t})
  13662. Specifies whether @command{sshd} should print the date and time of the
  13663. last user login when a user logs in interactively.
  13664. @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
  13665. Configures external subsystems (e.g.@: file transfer daemon).
  13666. This is a list of two-element lists, each of which containing the
  13667. subsystem name and a command (with optional arguments) to execute upon
  13668. subsystem request.
  13669. The command @command{internal-sftp} implements an in-process SFTP
  13670. server. Alternatively, one can specify the @command{sftp-server} command:
  13671. @lisp
  13672. (service openssh-service-type
  13673. (openssh-configuration
  13674. (subsystems
  13675. `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
  13676. @end lisp
  13677. @item @code{accepted-environment} (default: @code{'()})
  13678. List of strings describing which environment variables may be exported.
  13679. Each string gets on its own line. See the @code{AcceptEnv} option in
  13680. @code{man sshd_config}.
  13681. This example allows ssh-clients to export the @env{COLORTERM} variable.
  13682. It is set by terminal emulators, which support colors. You can use it in
  13683. your shell's resource file to enable colors for the prompt and commands
  13684. if this variable is set.
  13685. @lisp
  13686. (service openssh-service-type
  13687. (openssh-configuration
  13688. (accepted-environment '("COLORTERM"))))
  13689. @end lisp
  13690. @item @code{authorized-keys} (default: @code{'()})
  13691. @cindex authorized keys, SSH
  13692. @cindex SSH authorized keys
  13693. This is the list of authorized keys. Each element of the list is a user
  13694. name followed by one or more file-like objects that represent SSH public
  13695. keys. For example:
  13696. @lisp
  13697. (openssh-configuration
  13698. (authorized-keys
  13699. `(("rekado" ,(local-file "rekado.pub"))
  13700. ("chris" ,(local-file "chris.pub"))
  13701. ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
  13702. @end lisp
  13703. @noindent
  13704. registers the specified public keys for user accounts @code{rekado},
  13705. @code{chris}, and @code{root}.
  13706. Additional authorized keys can be specified @i{via}
  13707. @code{service-extension}.
  13708. Note that this does @emph{not} interfere with the use of
  13709. @file{~/.ssh/authorized_keys}.
  13710. @item @code{log-level} (default: @code{'info})
  13711. This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
  13712. @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
  13713. page for @file{sshd_config} for the full list of level names.
  13714. @item @code{extra-content} (default: @code{""})
  13715. This field can be used to append arbitrary text to the configuration file. It
  13716. is especially useful for elaborate configurations that cannot be expressed
  13717. otherwise. This configuration, for example, would generally disable root
  13718. logins, but permit them from one specific IP address:
  13719. @lisp
  13720. (openssh-configuration
  13721. (extra-content "\
  13722. Match Address 192.168.0.1
  13723. PermitRootLogin yes"))
  13724. @end lisp
  13725. @end table
  13726. @end deftp
  13727. @deffn {Scheme Procedure} dropbear-service [@var{config}]
  13728. Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
  13729. daemon} with the given @var{config}, a @code{<dropbear-configuration>}
  13730. object.
  13731. For example, to specify a Dropbear service listening on port 1234, add
  13732. this call to the operating system's @code{services} field:
  13733. @lisp
  13734. (dropbear-service (dropbear-configuration
  13735. (port-number 1234)))
  13736. @end lisp
  13737. @end deffn
  13738. @deftp {Data Type} dropbear-configuration
  13739. This data type represents the configuration of a Dropbear SSH daemon.
  13740. @table @asis
  13741. @item @code{dropbear} (default: @var{dropbear})
  13742. The Dropbear package to use.
  13743. @item @code{port-number} (default: 22)
  13744. The TCP port where the daemon waits for incoming connections.
  13745. @item @code{syslog-output?} (default: @code{#t})
  13746. Whether to enable syslog output.
  13747. @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
  13748. File name of the daemon's PID file.
  13749. @item @code{root-login?} (default: @code{#f})
  13750. Whether to allow @code{root} logins.
  13751. @item @code{allow-empty-passwords?} (default: @code{#f})
  13752. Whether to allow empty passwords.
  13753. @item @code{password-authentication?} (default: @code{#t})
  13754. Whether to enable password-based authentication.
  13755. @end table
  13756. @end deftp
  13757. @cindex AutoSSH
  13758. @deffn {Scheme Variable} autossh-service-type
  13759. This is the type for the @uref{https://www.harding.motd.ca/autossh,
  13760. AutoSSH} program that runs a copy of @command{ssh} and monitors it,
  13761. restarting it as necessary should it die or stop passing traffic.
  13762. AutoSSH can be run manually from the command-line by passing arguments
  13763. to the binary @command{autossh} from the package @code{autossh}, but it
  13764. can also be run as a Guix service. This latter use case is documented
  13765. here.
  13766. AutoSSH can be used to forward local traffic to a remote machine using
  13767. an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
  13768. is run as.
  13769. For example, to specify a service running autossh as the user
  13770. @code{pino} and forwarding all local connections to port @code{8081} to
  13771. @code{remote:8081} using an SSH tunnel, add this call to the operating
  13772. system's @code{services} field:
  13773. @lisp
  13774. (service autossh-service-type
  13775. (autossh-configuration
  13776. (user "pino")
  13777. (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
  13778. @end lisp
  13779. @end deffn
  13780. @deftp {Data Type} autossh-configuration
  13781. This data type represents the configuration of an AutoSSH service.
  13782. @table @asis
  13783. @item @code{user} (default @code{"autossh"})
  13784. The user as which the AutoSSH service is to be run.
  13785. This assumes that the specified user exists.
  13786. @item @code{poll} (default @code{600})
  13787. Specifies the connection poll time in seconds.
  13788. @item @code{first-poll} (default @code{#f})
  13789. Specifies how many seconds AutoSSH waits before the first connection
  13790. test. After this first test, polling is resumed at the pace defined in
  13791. @code{poll}. When set to @code{#f}, the first poll is not treated
  13792. specially and will also use the connection poll specified in
  13793. @code{poll}.
  13794. @item @code{gate-time} (default @code{30})
  13795. Specifies how many seconds an SSH connection must be active before it is
  13796. considered successful.
  13797. @item @code{log-level} (default @code{1})
  13798. The log level, corresponding to the levels used by syslog---so @code{0}
  13799. is the most silent while @code{7} is the chattiest.
  13800. @item @code{max-start} (default @code{#f})
  13801. The maximum number of times SSH may be (re)started before AutoSSH exits.
  13802. When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
  13803. @item @code{message} (default @code{""})
  13804. The message to append to the echo message sent when testing connections.
  13805. @item @code{port} (default @code{"0"})
  13806. The ports used for monitoring the connection. When set to @code{"0"},
  13807. monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
  13808. a positive integer, ports @var{n} and @var{n}+1 are used for
  13809. monitoring the connection, such that port @var{n} is the base
  13810. monitoring port and @code{n+1} is the echo port. When set to
  13811. @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
  13812. integers, the ports @var{n} and @var{m} are used for monitoring the
  13813. connection, such that port @var{n} is the base monitoring port and
  13814. @var{m} is the echo port.
  13815. @item @code{ssh-options} (default @code{'()})
  13816. The list of command-line arguments to pass to @command{ssh} when it is
  13817. run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
  13818. may cause undefined behaviour.
  13819. @end table
  13820. @end deftp
  13821. @cindex WebSSH
  13822. @deffn {Scheme Variable} webssh-service-type
  13823. This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
  13824. program that runs a web SSH client. WebSSH can be run manually from the
  13825. command-line by passing arguments to the binary @command{wssh} from the
  13826. package @code{webssh}, but it can also be run as a Guix service. This
  13827. latter use case is documented here.
  13828. For example, to specify a service running WebSSH on loopback interface
  13829. on port @code{8888} with reject policy with a list of allowed to
  13830. connection hosts, and NGINX as a reverse-proxy to this service listening
  13831. for HTTPS connection, add this call to the operating system's
  13832. @code{services} field:
  13833. @lisp
  13834. (service webssh-service-type
  13835. (webssh-configuration (address "127.0.0.1")
  13836. (port 8888)
  13837. (policy 'reject)
  13838. (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
  13839. "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
  13840. (service nginx-service-type
  13841. (nginx-configuration
  13842. (server-blocks
  13843. (list
  13844. (nginx-server-configuration
  13845. (inherit %webssh-configuration-nginx)
  13846. (server-name '("webssh.example.com"))
  13847. (listen '("443 ssl"))
  13848. (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
  13849. (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
  13850. (locations
  13851. (cons (nginx-location-configuration
  13852. (uri "/.well-known")
  13853. (body '("root /var/www;")))
  13854. (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
  13855. @end lisp
  13856. @end deffn
  13857. @deftp {Data Type} webssh-configuration
  13858. Data type representing the configuration for @code{webssh-service}.
  13859. @table @asis
  13860. @item @code{package} (default: @var{webssh})
  13861. @code{webssh} package to use.
  13862. @item @code{user-name} (default: @var{"webssh"})
  13863. User name or user ID that file transfers to and from that module should take
  13864. place.
  13865. @item @code{group-name} (default: @var{"webssh"})
  13866. Group name or group ID that will be used when accessing the module.
  13867. @item @code{address} (default: @var{#f})
  13868. IP address on which @command{webssh} listens for incoming connections.
  13869. @item @code{port} (default: @var{8888})
  13870. TCP port on which @command{webssh} listens for incoming connections.
  13871. @item @code{policy} (default: @var{#f})
  13872. Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
  13873. @item @code{known-hosts} (default: @var{'()})
  13874. List of hosts which allowed for SSH connection from @command{webssh}.
  13875. @item @code{log-file} (default: @file{"/var/log/webssh.log"})
  13876. Name of the file where @command{webssh} writes its log file.
  13877. @item @code{log-level} (default: @var{#f})
  13878. Logging level.
  13879. @end table
  13880. @end deftp
  13881. @defvr {Scheme Variable} %facebook-host-aliases
  13882. This variable contains a string for use in @file{/etc/hosts}
  13883. (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
  13884. line contains a entry that maps a known server name of the Facebook
  13885. on-line service---e.g., @code{www.facebook.com}---to the local
  13886. host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
  13887. This variable is typically used in the @code{hosts-file} field of an
  13888. @code{operating-system} declaration (@pxref{operating-system Reference,
  13889. @file{/etc/hosts}}):
  13890. @lisp
  13891. (use-modules (gnu) (guix))
  13892. (operating-system
  13893. (host-name "mymachine")
  13894. ;; ...
  13895. (hosts-file
  13896. ;; Create a /etc/hosts file with aliases for "localhost"
  13897. ;; and "mymachine", as well as for Facebook servers.
  13898. (plain-file "hosts"
  13899. (string-append (local-host-aliases host-name)
  13900. %facebook-host-aliases))))
  13901. @end lisp
  13902. This mechanism can prevent programs running locally, such as Web
  13903. browsers, from accessing Facebook.
  13904. @end defvr
  13905. The @code{(gnu services avahi)} provides the following definition.
  13906. @defvr {Scheme Variable} avahi-service-type
  13907. This is the service that runs @command{avahi-daemon}, a system-wide
  13908. mDNS/DNS-SD responder that allows for service discovery and
  13909. ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
  13910. Its value must be an @code{avahi-configuration} record---see below.
  13911. This service extends the name service cache daemon (nscd) so that it can
  13912. resolve @code{.local} host names using
  13913. @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
  13914. Service Switch}, for information on host name resolution.
  13915. Additionally, add the @var{avahi} package to the system profile so that
  13916. commands such as @command{avahi-browse} are directly usable.
  13917. @end defvr
  13918. @deftp {Data Type} avahi-configuration
  13919. Data type representation the configuration for Avahi.
  13920. @table @asis
  13921. @item @code{host-name} (default: @code{#f})
  13922. If different from @code{#f}, use that as the host name to
  13923. publish for this machine; otherwise, use the machine's actual host name.
  13924. @item @code{publish?} (default: @code{#t})
  13925. When true, allow host names and services to be published (broadcast) over the
  13926. network.
  13927. @item @code{publish-workstation?} (default: @code{#t})
  13928. When true, @command{avahi-daemon} publishes the machine's host name and IP
  13929. address via mDNS on the local network. To view the host names published on
  13930. your local network, you can run:
  13931. @example
  13932. avahi-browse _workstation._tcp
  13933. @end example
  13934. @item @code{wide-area?} (default: @code{#f})
  13935. When true, DNS-SD over unicast DNS is enabled.
  13936. @item @code{ipv4?} (default: @code{#t})
  13937. @itemx @code{ipv6?} (default: @code{#t})
  13938. These fields determine whether to use IPv4/IPv6 sockets.
  13939. @item @code{domains-to-browse} (default: @code{'()})
  13940. This is a list of domains to browse.
  13941. @end table
  13942. @end deftp
  13943. @deffn {Scheme Variable} openvswitch-service-type
  13944. This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
  13945. service, whose value should be an @code{openvswitch-configuration}
  13946. object.
  13947. @end deffn
  13948. @deftp {Data Type} openvswitch-configuration
  13949. Data type representing the configuration of Open vSwitch, a multilayer
  13950. virtual switch which is designed to enable massive network automation
  13951. through programmatic extension.
  13952. @table @asis
  13953. @item @code{package} (default: @var{openvswitch})
  13954. Package object of the Open vSwitch.
  13955. @end table
  13956. @end deftp
  13957. @defvr {Scheme Variable} pagekite-service-type
  13958. This is the service type for the @uref{https://pagekite.net, PageKite} service,
  13959. a tunneling solution for making localhost servers publicly visible, even from
  13960. behind restrictive firewalls or NAT without forwarded ports. The value for
  13961. this service type is a @code{pagekite-configuration} record.
  13962. Here's an example exposing the local HTTP and SSH daemons:
  13963. @lisp
  13964. (service pagekite-service-type
  13965. (pagekite-configuration
  13966. (kites '("http:@@kitename:localhost:80:@@kitesecret"
  13967. "raw/22:@@kitename:localhost:22:@@kitesecret"))
  13968. (extra-file "/etc/pagekite.rc")))
  13969. @end lisp
  13970. @end defvr
  13971. @deftp {Data Type} pagekite-configuration
  13972. Data type representing the configuration of PageKite.
  13973. @table @asis
  13974. @item @code{package} (default: @var{pagekite})
  13975. Package object of PageKite.
  13976. @item @code{kitename} (default: @code{#f})
  13977. PageKite name for authenticating to the frontend server.
  13978. @item @code{kitesecret} (default: @code{#f})
  13979. Shared secret for authenticating to the frontend server. You should probably
  13980. put this inside @code{extra-file} instead.
  13981. @item @code{frontend} (default: @code{#f})
  13982. Connect to the named PageKite frontend server instead of the
  13983. @uref{https://pagekite.net,,pagekite.net} service.
  13984. @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
  13985. List of service kites to use. Exposes HTTP on port 80 by default. The format
  13986. is @code{proto:kitename:host:port:secret}.
  13987. @item @code{extra-file} (default: @code{#f})
  13988. Extra configuration file to read, which you are expected to create manually.
  13989. Use this to add additional options and manage shared secrets out-of-band.
  13990. @end table
  13991. @end deftp
  13992. @defvr {Scheme Variable} yggdrasil-service-type
  13993. The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
  13994. Yggdrasil network}, an early-stage implementation of a fully end-to-end
  13995. encrypted IPv6 network.
  13996. @quotation
  13997. Yggdrasil provides name-independent routing with cryptographically generated
  13998. addresses. Static addressing means you can keep the same address as long as
  13999. you want, even if you move to a new location, or generate a new address (by
  14000. generating new keys) whenever you want.
  14001. @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
  14002. @end quotation
  14003. Pass it a value of @code{yggdrasil-configuration} to connect it to public
  14004. peers and/or local peers.
  14005. Here is an example using public peers and a static address. The static
  14006. signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
  14007. (the default value for @code{config-file}).
  14008. @lisp
  14009. ;; part of the operating-system declaration
  14010. (service yggdrasil-service-type
  14011. (yggdrasil-configuration
  14012. (autoconf? #f) ;; use only the public peers
  14013. (json-config
  14014. ;; choose one from
  14015. ;; https://github.com/yggdrasil-network/public-peers
  14016. '((peers . #("tcp://1.2.3.4:1337"))))
  14017. ;; /etc/yggdrasil-private.conf is the default value for config-file
  14018. ))
  14019. @end lisp
  14020. @example
  14021. # sample content for /etc/yggdrasil-private.conf
  14022. @{
  14023. # Your public encryption key. Your peers may ask you for this to put
  14024. # into their AllowedEncryptionPublicKeys configuration.
  14025. EncryptionPublicKey: 378dc5...
  14026. # Your private encryption key. DO NOT share this with anyone!
  14027. EncryptionPrivateKey: 0777...
  14028. # Your public signing key. You should not ordinarily need to share
  14029. # this with anyone.
  14030. SigningPublicKey: e1664...
  14031. # Your private signing key. DO NOT share this with anyone!
  14032. SigningPrivateKey: 0589d...
  14033. @}
  14034. @end example
  14035. @end defvr
  14036. @deftp {Data Type} yggdrasil-configuration
  14037. Data type representing the configuration of Yggdrasil.
  14038. @table @asis
  14039. @item @code{package} (default: @code{yggdrasil})
  14040. Package object of Yggdrasil.
  14041. @item @code{json-config} (default: @code{'()})
  14042. Contents of @file{/etc/yggdrasil.conf}. Will be merged with
  14043. @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
  14044. the Guix store, which is readable to all users. @strong{Do not store your
  14045. private keys in it}. See the output of @code{yggdrasil -genconf} for a
  14046. quick overview of valid keys and their default values.
  14047. @item @code{autoconf?} (default: @code{#f})
  14048. Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
  14049. and peer with IPv6 neighbors.
  14050. @item @code{log-level} (default: @code{'info})
  14051. How much detail to include in logs. Use @code{'debug} for more detail.
  14052. @item @code{log-to} (default: @code{'stdout})
  14053. Where to send logs. By default, the service logs standard output to
  14054. @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
  14055. sends output to the running syslog service.
  14056. @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
  14057. What HJSON file to load sensitive data from. This is where private keys
  14058. should be stored, which are necessary to specify if you don't want a
  14059. randomized address after each restart. Use @code{#f} to disable. Options
  14060. defined in this file take precedence over @code{json-config}. Use the output
  14061. of @code{yggdrasil -genconf} as a starting point. To configure a static
  14062. address, delete everything except these options:
  14063. @itemize
  14064. @item @code{EncryptionPublicKey}
  14065. @item @code{EncryptionPrivateKey}
  14066. @item @code{SigningPublicKey}
  14067. @item @code{SigningPrivateKey}
  14068. @end itemize
  14069. @end table
  14070. @end deftp
  14071. @cindex keepalived
  14072. @deffn {Scheme Variable} keepalived-service-type
  14073. This is the type for the @uref{https://www.keepalived.org/, Keepalived}
  14074. routing software, @command{keepalived}. Its value must be an
  14075. @code{keepalived-configuration} record as in this example for master
  14076. machine:
  14077. @lisp
  14078. (service keepalived-service-type
  14079. (keepalived-configuration
  14080. (config-file (local-file "keepalived-master.conf"))))
  14081. @end lisp
  14082. where @file{keepalived-master.conf}:
  14083. @example
  14084. vrrp_instance my-group @{
  14085. state MASTER
  14086. interface enp9s0
  14087. virtual_router_id 100
  14088. priority 100
  14089. unicast_peer @{ 10.0.0.2 @}
  14090. virtual_ipaddress @{
  14091. 10.0.0.4/24
  14092. @}
  14093. @}
  14094. @end example
  14095. and for backup machine:
  14096. @lisp
  14097. (service keepalived-service-type
  14098. (keepalived-configuration
  14099. (config-file (local-file "keepalived-backup.conf"))))
  14100. @end lisp
  14101. where @file{keepalived-backup.conf}:
  14102. @example
  14103. vrrp_instance my-group @{
  14104. state BACKUP
  14105. interface enp9s0
  14106. virtual_router_id 100
  14107. priority 99
  14108. unicast_peer @{ 10.0.0.3 @}
  14109. virtual_ipaddress @{
  14110. 10.0.0.4/24
  14111. @}
  14112. @}
  14113. @end example
  14114. @end deffn
  14115. @node Unattended Upgrades
  14116. @subsection Unattended Upgrades
  14117. @cindex unattended upgrades
  14118. @cindex upgrades, unattended
  14119. Guix provides a service to perform @emph{unattended upgrades}:
  14120. periodically, the system automatically reconfigures itself from the
  14121. latest Guix. Guix System has several properties that make unattended
  14122. upgrades safe:
  14123. @itemize
  14124. @item
  14125. upgrades are transactional (either the upgrade succeeds or it fails, but
  14126. you cannot end up with an ``in-between'' system state);
  14127. @item
  14128. the upgrade log is kept---you can view it with @command{guix system
  14129. list-generations}---and you can roll back to any previous generation,
  14130. should the upgraded system fail to behave as intended;
  14131. @item
  14132. channel code is authenticated so you know you can only run genuine code
  14133. (@pxref{Channels});
  14134. @item
  14135. @command{guix system reconfigure} prevents downgrades, which makes it
  14136. immune to @dfn{downgrade attacks}.
  14137. @end itemize
  14138. To set up unattended upgrades, add an instance of
  14139. @code{unattended-upgrade-service-type} like the one below to the list of
  14140. your operating system services:
  14141. @lisp
  14142. (service unattended-upgrade-service-type)
  14143. @end lisp
  14144. The defaults above set up weekly upgrades: every Sunday at midnight.
  14145. You do not need to provide the operating system configuration file: it
  14146. uses @file{/run/current-system/configuration.scm}, which ensures it
  14147. always uses your latest configuration---@pxref{provenance-service-type},
  14148. for more information about this file.
  14149. There are several things that can be configured, in particular the
  14150. periodicity and services (daemons) to be restarted upon completion.
  14151. When the upgrade is successful, the service takes care of deleting
  14152. system generations older that some threshold, as per @command{guix
  14153. system delete-generations}. See the reference below for details.
  14154. To ensure that upgrades are actually happening, you can run
  14155. @command{guix system describe}. To investigate upgrade failures, visit
  14156. the unattended upgrade log file (see below).
  14157. @defvr {Scheme Variable} unattended-upgrade-service-type
  14158. This is the service type for unattended upgrades. It sets up an mcron
  14159. job (@pxref{Scheduled Job Execution}) that runs @command{guix system
  14160. reconfigure} from the latest version of the specified channels.
  14161. Its value must be a @code{unattended-upgrade-configuration} record (see
  14162. below).
  14163. @end defvr
  14164. @deftp {Data Type} unattended-upgrade-configuration
  14165. This data type represents the configuration of the unattended upgrade
  14166. service. The following fields are available:
  14167. @table @asis
  14168. @item @code{schedule} (default: @code{"30 01 * * 0"})
  14169. This is the schedule of upgrades, expressed as a gexp containing an
  14170. mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
  14171. mcron, GNU@tie{}mcron}).
  14172. @item @code{channels} (default: @code{#~%default-channels})
  14173. This gexp specifies the channels to use for the upgrade
  14174. (@pxref{Channels}). By default, the tip of the official @code{guix}
  14175. channel is used.
  14176. @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
  14177. This field specifies the operating system configuration file to use.
  14178. The default is to reuse the config file of the current configuration.
  14179. There are cases, though, where referring to
  14180. @file{/run/current-system/configuration.scm} is not enough, for instance
  14181. because that file refers to extra files (SSH public keys, extra
  14182. configuration files, etc.) @i{via} @code{local-file} and similar
  14183. constructs. For those cases, we recommend something along these lines:
  14184. @lisp
  14185. (unattended-upgrade-configuration
  14186. (operating-system-file
  14187. (file-append (local-file "." "config-dir" #:recursive? #t)
  14188. "/config.scm")))
  14189. @end lisp
  14190. The effect here is to import all of the current directory into the
  14191. store, and to refer to @file{config.scm} within that directory.
  14192. Therefore, uses of @code{local-file} within @file{config.scm} will work
  14193. as expected. @xref{G-Expressions}, for information about
  14194. @code{local-file} and @code{file-append}.
  14195. @item @code{services-to-restart} (default: @code{'(mcron)})
  14196. This field specifies the Shepherd services to restart when the upgrade
  14197. completes.
  14198. Those services are restarted right away upon completion, as with
  14199. @command{herd restart}, which ensures that the latest version is
  14200. running---remember that by default @command{guix system reconfigure}
  14201. only restarts services that are not currently running, which is
  14202. conservative: it minimizes disruption but leaves outdated services
  14203. running.
  14204. Use @command{herd status} to find out candidates for restarting.
  14205. @xref{Services}, for general information about services. Common
  14206. services to restart would include @code{ntpd} and @code{ssh-daemon}.
  14207. By default, the @code{mcron} service is restarted. This ensures that
  14208. the latest version of the unattended upgrade job will be used next time.
  14209. @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
  14210. This is the expiration time in seconds for system generations. System
  14211. generations older that this amount of time are deleted with
  14212. @command{guix system delete-generations} when an upgrade completes.
  14213. @quotation Note
  14214. The unattended upgrade service does not run the garbage collector. You
  14215. will probably want to set up your own mcron job to run @command{guix gc}
  14216. periodically.
  14217. @end quotation
  14218. @item @code{maximum-duration} (default: @code{3600})
  14219. Maximum duration in seconds for the upgrade; past that time, the upgrade
  14220. aborts.
  14221. This is primarily useful to ensure the upgrade does not end up
  14222. rebuilding or re-downloading ``the world''.
  14223. @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
  14224. File where unattended upgrades are logged.
  14225. @end table
  14226. @end deftp
  14227. @node X Window
  14228. @subsection X Window
  14229. @cindex X11
  14230. @cindex X Window System
  14231. @cindex login manager
  14232. Support for the X Window graphical display system---specifically
  14233. Xorg---is provided by the @code{(gnu services xorg)} module. Note that
  14234. there is no @code{xorg-service} procedure. Instead, the X server is
  14235. started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
  14236. @cindex GDM
  14237. @cindex GNOME, login manager
  14238. GDM of course allows users to log in into window managers and desktop
  14239. environments other than GNOME; for those using GNOME, GDM is required for
  14240. features such as automatic screen locking.
  14241. @cindex window manager
  14242. To use X11, you must install at least one @dfn{window manager}---for
  14243. example the @code{windowmaker} or @code{openbox} packages---preferably
  14244. by adding it to the @code{packages} field of your operating system
  14245. definition (@pxref{operating-system Reference, system-wide packages}).
  14246. @defvr {Scheme Variable} gdm-service-type
  14247. This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
  14248. Desktop Manager} (GDM), a program that manages graphical display servers and
  14249. handles graphical user logins. Its value must be a @code{gdm-configuration}
  14250. (see below).
  14251. @cindex session types (X11)
  14252. @cindex X11 session types
  14253. GDM looks for @dfn{session types} described by the @file{.desktop} files in
  14254. @file{/run/current-system/profile/share/xsessions} and allows users to choose
  14255. a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
  14256. and @code{i3} provide @file{.desktop} files; adding them to the system-wide
  14257. set of packages automatically makes them available at the log-in screen.
  14258. In addition, @file{~/.xsession} files are honored. When available,
  14259. @file{~/.xsession} must be an executable that starts a window manager
  14260. and/or other X clients.
  14261. @end defvr
  14262. @deftp {Data Type} gdm-configuration
  14263. @table @asis
  14264. @item @code{auto-login?} (default: @code{#f})
  14265. @itemx @code{default-user} (default: @code{#f})
  14266. When @code{auto-login?} is false, GDM presents a log-in screen.
  14267. When @code{auto-login?} is true, GDM logs in directly as
  14268. @code{default-user}.
  14269. @item @code{debug?} (default: @code{#f})
  14270. When true, GDM writes debug messages to its log.
  14271. @item @code{gnome-shell-assets} (default: ...)
  14272. List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
  14273. @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
  14274. Configuration of the Xorg graphical server.
  14275. @item @code{xsession} (default: @code{(xinitrc)})
  14276. Script to run before starting a X session.
  14277. @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
  14278. File name of the @code{dbus-daemon} executable.
  14279. @item @code{gdm} (default: @code{gdm})
  14280. The GDM package to use.
  14281. @end table
  14282. @end deftp
  14283. @defvr {Scheme Variable} slim-service-type
  14284. This is the type for the SLiM graphical login manager for X11.
  14285. Like GDM, SLiM looks for session types described by @file{.desktop} files and
  14286. allows users to choose a session from the log-in screen using @kbd{F1}. It
  14287. also honors @file{~/.xsession} files.
  14288. Unlike GDM, SLiM does not spawn the user session on a different VT after
  14289. logging in, which means that you can only start one graphical session. If you
  14290. want to be able to run multiple graphical sessions at the same time you have
  14291. to add multiple SLiM services to your system services. The following example
  14292. shows how to replace the default GDM service with two SLiM services on tty7
  14293. and tty8.
  14294. @lisp
  14295. (use-modules (gnu services)
  14296. (gnu services desktop)
  14297. (gnu services xorg)
  14298. (srfi srfi-1)) ;for 'remove'
  14299. (operating-system
  14300. ;; ...
  14301. (services (cons* (service slim-service-type (slim-configuration
  14302. (display ":0")
  14303. (vt "vt7")))
  14304. (service slim-service-type (slim-configuration
  14305. (display ":1")
  14306. (vt "vt8")))
  14307. (remove (lambda (service)
  14308. (eq? (service-kind service) gdm-service-type))
  14309. %desktop-services))))
  14310. @end lisp
  14311. @end defvr
  14312. @deftp {Data Type} slim-configuration
  14313. Data type representing the configuration of @code{slim-service-type}.
  14314. @table @asis
  14315. @item @code{allow-empty-passwords?} (default: @code{#t})
  14316. Whether to allow logins with empty passwords.
  14317. @item @code{auto-login?} (default: @code{#f})
  14318. @itemx @code{default-user} (default: @code{""})
  14319. When @code{auto-login?} is false, SLiM presents a log-in screen.
  14320. When @code{auto-login?} is true, SLiM logs in directly as
  14321. @code{default-user}.
  14322. @item @code{theme} (default: @code{%default-slim-theme})
  14323. @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
  14324. The graphical theme to use and its name.
  14325. @item @code{auto-login-session} (default: @code{#f})
  14326. If true, this must be the name of the executable to start as the default
  14327. session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
  14328. If false, a session described by one of the available @file{.desktop}
  14329. files in @code{/run/current-system/profile} and @code{~/.guix-profile}
  14330. will be used.
  14331. @quotation Note
  14332. You must install at least one window manager in the system profile or in
  14333. your user profile. Failing to do that, if @code{auto-login-session} is
  14334. false, you will be unable to log in.
  14335. @end quotation
  14336. @item @code{xorg-configuration} (default @code{(xorg-configuration)})
  14337. Configuration of the Xorg graphical server.
  14338. @item @code{display} (default @code{":0"})
  14339. The display on which to start the Xorg graphical server.
  14340. @item @code{vt} (default @code{"vt7"})
  14341. The VT on which to start the Xorg graphical server.
  14342. @item @code{xauth} (default: @code{xauth})
  14343. The XAuth package to use.
  14344. @item @code{shepherd} (default: @code{shepherd})
  14345. The Shepherd package used when invoking @command{halt} and
  14346. @command{reboot}.
  14347. @item @code{sessreg} (default: @code{sessreg})
  14348. The sessreg package used in order to register the session.
  14349. @item @code{slim} (default: @code{slim})
  14350. The SLiM package to use.
  14351. @end table
  14352. @end deftp
  14353. @defvr {Scheme Variable} %default-theme
  14354. @defvrx {Scheme Variable} %default-theme-name
  14355. The default SLiM theme and its name.
  14356. @end defvr
  14357. @deftp {Data Type} sddm-configuration
  14358. This is the data type representing the SDDM service configuration.
  14359. @table @asis
  14360. @item @code{display-server} (default: "x11")
  14361. Select display server to use for the greeter. Valid values are
  14362. @samp{"x11"} or @samp{"wayland"}.
  14363. @item @code{numlock} (default: "on")
  14364. Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
  14365. @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
  14366. Command to run when halting.
  14367. @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
  14368. Command to run when rebooting.
  14369. @item @code{theme} (default "maldives")
  14370. Theme to use. Default themes provided by SDDM are @samp{"elarun"},
  14371. @samp{"maldives"} or @samp{"maya"}.
  14372. @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
  14373. Directory to look for themes.
  14374. @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
  14375. Directory to look for faces.
  14376. @item @code{default-path} (default "/run/current-system/profile/bin")
  14377. Default PATH to use.
  14378. @item @code{minimum-uid} (default: 1000)
  14379. Minimum UID displayed in SDDM and allowed for log-in.
  14380. @item @code{maximum-uid} (default: 2000)
  14381. Maximum UID to display in SDDM.
  14382. @item @code{remember-last-user?} (default #t)
  14383. Remember last user.
  14384. @item @code{remember-last-session?} (default #t)
  14385. Remember last session.
  14386. @item @code{hide-users} (default "")
  14387. Usernames to hide from SDDM greeter.
  14388. @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
  14389. Users with shells listed will be hidden from the SDDM greeter.
  14390. @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
  14391. Script to run before starting a wayland session.
  14392. @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
  14393. Directory to look for desktop files starting wayland sessions.
  14394. @item @code{xorg-configuration} (default @code{(xorg-configuration)})
  14395. Configuration of the Xorg graphical server.
  14396. @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
  14397. Path to xauth.
  14398. @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
  14399. Path to Xephyr.
  14400. @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
  14401. Script to run after starting xorg-server.
  14402. @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
  14403. Script to run before stopping xorg-server.
  14404. @item @code{xsession-command} (default: @code{xinitrc})
  14405. Script to run before starting a X session.
  14406. @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
  14407. Directory to look for desktop files starting X sessions.
  14408. @item @code{minimum-vt} (default: 7)
  14409. Minimum VT to use.
  14410. @item @code{auto-login-user} (default "")
  14411. User to use for auto-login.
  14412. @item @code{auto-login-session} (default "")
  14413. Desktop file to use for auto-login.
  14414. @item @code{relogin?} (default #f)
  14415. Relogin after logout.
  14416. @end table
  14417. @end deftp
  14418. @cindex login manager
  14419. @cindex X11 login
  14420. @defvr {Scheme Variable} sddm-service-type
  14421. This is the type of the service to run the
  14422. @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
  14423. must be a @code{sddm-configuration} record (see below).
  14424. Here's an example use:
  14425. @lisp
  14426. (service sddm-service-type
  14427. (sddm-configuration
  14428. (auto-login-user "alice")
  14429. (auto-login-session "xfce.desktop")))
  14430. @end lisp
  14431. @end defvr
  14432. @deftp {Data Type} sddm-configuration
  14433. This data type represents the configuration of the SDDM login manager.
  14434. The available fields are:
  14435. @table @asis
  14436. @item @code{sddm} (default: @code{sddm})
  14437. The SDDM package to use.
  14438. @item @code{display-server} (default: @code{"x11"})
  14439. This must be either @code{"x11"} or @code{"wayland"}.
  14440. @c FIXME: Add more fields.
  14441. @item @code{auto-login-user} (default: @code{""})
  14442. If non-empty, this is the user account under which to log in
  14443. automatically.
  14444. @item @code{auto-login-session} (default: @code{""})
  14445. If non-empty, this is the @file{.desktop} file name to use as the
  14446. auto-login session.
  14447. @end table
  14448. @end deftp
  14449. @cindex Xorg, configuration
  14450. @deftp {Data Type} xorg-configuration
  14451. This data type represents the configuration of the Xorg graphical display
  14452. server. Note that there is no Xorg service; instead, the X server is started
  14453. by a ``display manager'' such as GDM, SDDM, and SLiM@. Thus, the configuration
  14454. of these display managers aggregates an @code{xorg-configuration} record.
  14455. @table @asis
  14456. @item @code{modules} (default: @code{%default-xorg-modules})
  14457. This is a list of @dfn{module packages} loaded by the Xorg
  14458. server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
  14459. @item @code{fonts} (default: @code{%default-xorg-fonts})
  14460. This is a list of font directories to add to the server's @dfn{font path}.
  14461. @item @code{drivers} (default: @code{'()})
  14462. This must be either the empty list, in which case Xorg chooses a graphics
  14463. driver automatically, or a list of driver names that will be tried in this
  14464. order---e.g., @code{("modesetting" "vesa")}.
  14465. @item @code{resolutions} (default: @code{'()})
  14466. When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
  14467. resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
  14468. 768) (640 480))}.
  14469. @cindex keyboard layout, for Xorg
  14470. @cindex keymap, for Xorg
  14471. @item @code{keyboard-layout} (default: @code{#f})
  14472. If this is @code{#f}, Xorg uses the default keyboard layout---usually US
  14473. English (``qwerty'') for a 105-key PC keyboard.
  14474. Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
  14475. layout in use when Xorg is running. @xref{Keyboard Layout}, for more
  14476. information on how to specify the keyboard layout.
  14477. @item @code{extra-config} (default: @code{'()})
  14478. This is a list of strings or objects appended to the configuration file. It
  14479. is used to pass extra text to be added verbatim to the configuration file.
  14480. @item @code{server} (default: @code{xorg-server})
  14481. This is the package providing the Xorg server.
  14482. @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
  14483. This is the list of command-line arguments to pass to the X server. The
  14484. default is @code{-nolisten tcp}.
  14485. @end table
  14486. @end deftp
  14487. @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
  14488. [@var{login-manager-service-type}]
  14489. Tell the log-in manager (of type @var{login-manager-service-type}) to use
  14490. @var{config}, an @code{<xorg-configuration>} record.
  14491. Since the Xorg configuration is embedded in the log-in manager's
  14492. configuration---e.g., @code{gdm-configuration}---this procedure provides a
  14493. shorthand to set the Xorg configuration.
  14494. @end deffn
  14495. @deffn {Scheme Procedure} xorg-start-command [@var{config}]
  14496. Return a @code{startx} script in which the modules, fonts, etc. specified
  14497. in @var{config}, are available. The result should be used in place of
  14498. @code{startx}.
  14499. Usually the X server is started by a login manager.
  14500. @end deffn
  14501. @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
  14502. Add @var{package}, a package for a screen locker or screen saver whose
  14503. command is @var{program}, to the set of setuid programs and add a PAM entry
  14504. for it. For example:
  14505. @lisp
  14506. (screen-locker-service xlockmore "xlock")
  14507. @end lisp
  14508. makes the good ol' XlockMore usable.
  14509. @end deffn
  14510. @node Printing Services
  14511. @subsection Printing Services
  14512. @cindex printer support with CUPS
  14513. The @code{(gnu services cups)} module provides a Guix service definition
  14514. for the CUPS printing service. To add printer support to a Guix
  14515. system, add a @code{cups-service} to the operating system definition:
  14516. @deffn {Scheme Variable} cups-service-type
  14517. The service type for the CUPS print server. Its value should be a valid
  14518. CUPS configuration (see below). To use the default settings, simply
  14519. write:
  14520. @lisp
  14521. (service cups-service-type)
  14522. @end lisp
  14523. @end deffn
  14524. The CUPS configuration controls the basic things about your CUPS
  14525. installation: what interfaces it listens on, what to do if a print job
  14526. fails, how much logging to do, and so on. To actually add a printer,
  14527. you have to visit the @url{http://localhost:631} URL, or use a tool such
  14528. as GNOME's printer configuration services. By default, configuring a
  14529. CUPS service will generate a self-signed certificate if needed, for
  14530. secure connections to the print server.
  14531. Suppose you want to enable the Web interface of CUPS and also add
  14532. support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
  14533. package and for HP printers @i{via} the @code{hplip-minimal} package.
  14534. You can do that directly, like this (you need to use the
  14535. @code{(gnu packages cups)} module):
  14536. @lisp
  14537. (service cups-service-type
  14538. (cups-configuration
  14539. (web-interface? #t)
  14540. (extensions
  14541. (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
  14542. @end lisp
  14543. Note: If you wish to use the Qt5 based GUI which comes with the hplip
  14544. package then it is suggested that you install the @code{hplip} package,
  14545. either in your OS configuration file or as your user.
  14546. The available configuration parameters follow. Each parameter
  14547. definition is preceded by its type; for example, @samp{string-list foo}
  14548. indicates that the @code{foo} parameter should be specified as a list of
  14549. strings. There is also a way to specify the configuration as a string,
  14550. if you have an old @code{cupsd.conf} file that you want to port over
  14551. from some other system; see the end for more details.
  14552. @c The following documentation was initially generated by
  14553. @c (generate-documentation) in (gnu services cups). Manually maintained
  14554. @c documentation is better, so we shouldn't hesitate to edit below as
  14555. @c needed. However if the change you want to make to this documentation
  14556. @c can be done in an automated way, it's probably easier to change
  14557. @c (generate-documentation) than to make it below and have to deal with
  14558. @c the churn as CUPS updates.
  14559. Available @code{cups-configuration} fields are:
  14560. @deftypevr {@code{cups-configuration} parameter} package cups
  14561. The CUPS package.
  14562. @end deftypevr
  14563. @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
  14564. Drivers and other extensions to the CUPS package.
  14565. @end deftypevr
  14566. @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
  14567. Configuration of where to write logs, what directories to use for print
  14568. spools, and related privileged configuration parameters.
  14569. Available @code{files-configuration} fields are:
  14570. @deftypevr {@code{files-configuration} parameter} log-location access-log
  14571. Defines the access log filename. Specifying a blank filename disables
  14572. access log generation. The value @code{stderr} causes log entries to be
  14573. sent to the standard error file when the scheduler is running in the
  14574. foreground, or to the system log daemon when run in the background. The
  14575. value @code{syslog} causes log entries to be sent to the system log
  14576. daemon. The server name may be included in filenames using the string
  14577. @code{%s}, as in @code{/var/log/cups/%s-access_log}.
  14578. Defaults to @samp{"/var/log/cups/access_log"}.
  14579. @end deftypevr
  14580. @deftypevr {@code{files-configuration} parameter} file-name cache-dir
  14581. Where CUPS should cache data.
  14582. Defaults to @samp{"/var/cache/cups"}.
  14583. @end deftypevr
  14584. @deftypevr {@code{files-configuration} parameter} string config-file-perm
  14585. Specifies the permissions for all configuration files that the scheduler
  14586. writes.
  14587. Note that the permissions for the printers.conf file are currently
  14588. masked to only allow access from the scheduler user (typically root).
  14589. This is done because printer device URIs sometimes contain sensitive
  14590. authentication information that should not be generally known on the
  14591. system. There is no way to disable this security feature.
  14592. Defaults to @samp{"0640"}.
  14593. @end deftypevr
  14594. @deftypevr {@code{files-configuration} parameter} log-location error-log
  14595. Defines the error log filename. Specifying a blank filename disables
  14596. error log generation. The value @code{stderr} causes log entries to be
  14597. sent to the standard error file when the scheduler is running in the
  14598. foreground, or to the system log daemon when run in the background. The
  14599. value @code{syslog} causes log entries to be sent to the system log
  14600. daemon. The server name may be included in filenames using the string
  14601. @code{%s}, as in @code{/var/log/cups/%s-error_log}.
  14602. Defaults to @samp{"/var/log/cups/error_log"}.
  14603. @end deftypevr
  14604. @deftypevr {@code{files-configuration} parameter} string fatal-errors
  14605. Specifies which errors are fatal, causing the scheduler to exit. The
  14606. kind strings are:
  14607. @table @code
  14608. @item none
  14609. No errors are fatal.
  14610. @item all
  14611. All of the errors below are fatal.
  14612. @item browse
  14613. Browsing initialization errors are fatal, for example failed connections
  14614. to the DNS-SD daemon.
  14615. @item config
  14616. Configuration file syntax errors are fatal.
  14617. @item listen
  14618. Listen or Port errors are fatal, except for IPv6 failures on the
  14619. loopback or @code{any} addresses.
  14620. @item log
  14621. Log file creation or write errors are fatal.
  14622. @item permissions
  14623. Bad startup file permissions are fatal, for example shared TLS
  14624. certificate and key files with world-read permissions.
  14625. @end table
  14626. Defaults to @samp{"all -browse"}.
  14627. @end deftypevr
  14628. @deftypevr {@code{files-configuration} parameter} boolean file-device?
  14629. Specifies whether the file pseudo-device can be used for new printer
  14630. queues. The URI @uref{file:///dev/null} is always allowed.
  14631. Defaults to @samp{#f}.
  14632. @end deftypevr
  14633. @deftypevr {@code{files-configuration} parameter} string group
  14634. Specifies the group name or ID that will be used when executing external
  14635. programs.
  14636. Defaults to @samp{"lp"}.
  14637. @end deftypevr
  14638. @deftypevr {@code{files-configuration} parameter} string log-file-perm
  14639. Specifies the permissions for all log files that the scheduler writes.
  14640. Defaults to @samp{"0644"}.
  14641. @end deftypevr
  14642. @deftypevr {@code{files-configuration} parameter} log-location page-log
  14643. Defines the page log filename. Specifying a blank filename disables
  14644. page log generation. The value @code{stderr} causes log entries to be
  14645. sent to the standard error file when the scheduler is running in the
  14646. foreground, or to the system log daemon when run in the background. The
  14647. value @code{syslog} causes log entries to be sent to the system log
  14648. daemon. The server name may be included in filenames using the string
  14649. @code{%s}, as in @code{/var/log/cups/%s-page_log}.
  14650. Defaults to @samp{"/var/log/cups/page_log"}.
  14651. @end deftypevr
  14652. @deftypevr {@code{files-configuration} parameter} string remote-root
  14653. Specifies the username that is associated with unauthenticated accesses
  14654. by clients claiming to be the root user. The default is @code{remroot}.
  14655. Defaults to @samp{"remroot"}.
  14656. @end deftypevr
  14657. @deftypevr {@code{files-configuration} parameter} file-name request-root
  14658. Specifies the directory that contains print jobs and other HTTP request
  14659. data.
  14660. Defaults to @samp{"/var/spool/cups"}.
  14661. @end deftypevr
  14662. @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
  14663. Specifies the level of security sandboxing that is applied to print
  14664. filters, backends, and other child processes of the scheduler; either
  14665. @code{relaxed} or @code{strict}. This directive is currently only
  14666. used/supported on macOS.
  14667. Defaults to @samp{strict}.
  14668. @end deftypevr
  14669. @deftypevr {@code{files-configuration} parameter} file-name server-keychain
  14670. Specifies the location of TLS certificates and private keys. CUPS will
  14671. look for public and private keys in this directory: @file{.crt} files
  14672. for PEM-encoded certificates and corresponding @file{.key} files for
  14673. PEM-encoded private keys.
  14674. Defaults to @samp{"/etc/cups/ssl"}.
  14675. @end deftypevr
  14676. @deftypevr {@code{files-configuration} parameter} file-name server-root
  14677. Specifies the directory containing the server configuration files.
  14678. Defaults to @samp{"/etc/cups"}.
  14679. @end deftypevr
  14680. @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
  14681. Specifies whether the scheduler calls fsync(2) after writing
  14682. configuration or state files.
  14683. Defaults to @samp{#f}.
  14684. @end deftypevr
  14685. @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
  14686. Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
  14687. @end deftypevr
  14688. @deftypevr {@code{files-configuration} parameter} file-name temp-dir
  14689. Specifies the directory where temporary files are stored.
  14690. Defaults to @samp{"/var/spool/cups/tmp"}.
  14691. @end deftypevr
  14692. @deftypevr {@code{files-configuration} parameter} string user
  14693. Specifies the user name or ID that is used when running external
  14694. programs.
  14695. Defaults to @samp{"lp"}.
  14696. @end deftypevr
  14697. @deftypevr {@code{files-configuration} parameter} string set-env
  14698. Set the specified environment variable to be passed to child processes.
  14699. Defaults to @samp{"variable value"}.
  14700. @end deftypevr
  14701. @end deftypevr
  14702. @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
  14703. Specifies the logging level for the AccessLog file. The @code{config}
  14704. level logs when printers and classes are added, deleted, or modified and
  14705. when configuration files are accessed or updated. The @code{actions}
  14706. level logs when print jobs are submitted, held, released, modified, or
  14707. canceled, and any of the conditions for @code{config}. The @code{all}
  14708. level logs all requests.
  14709. Defaults to @samp{actions}.
  14710. @end deftypevr
  14711. @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
  14712. Specifies whether to purge job history data automatically when it is no
  14713. longer required for quotas.
  14714. Defaults to @samp{#f}.
  14715. @end deftypevr
  14716. @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
  14717. Specifies a list of DNS-SD sub-types to advertise for each shared printer.
  14718. For example, @samp{"_cups" "_print"} will tell network clients that both
  14719. CUPS sharing and IPP Everywhere are supported.
  14720. Defaults to @samp{"_cups"}.
  14721. @end deftypevr
  14722. @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
  14723. Specifies which protocols to use for local printer sharing.
  14724. Defaults to @samp{dnssd}.
  14725. @end deftypevr
  14726. @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
  14727. Specifies whether the CUPS web interface is advertised.
  14728. Defaults to @samp{#f}.
  14729. @end deftypevr
  14730. @deftypevr {@code{cups-configuration} parameter} boolean browsing?
  14731. Specifies whether shared printers are advertised.
  14732. Defaults to @samp{#f}.
  14733. @end deftypevr
  14734. @deftypevr {@code{cups-configuration} parameter} string classification
  14735. Specifies the security classification of the server. Any valid banner
  14736. name can be used, including @samp{"classified"}, @samp{"confidential"},
  14737. @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
  14738. banner can be omitted to disable secure printing functions.
  14739. Defaults to @samp{""}.
  14740. @end deftypevr
  14741. @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
  14742. Specifies whether users may override the classification (cover page) of
  14743. individual print jobs using the @code{job-sheets} option.
  14744. Defaults to @samp{#f}.
  14745. @end deftypevr
  14746. @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
  14747. Specifies the default type of authentication to use.
  14748. Defaults to @samp{Basic}.
  14749. @end deftypevr
  14750. @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
  14751. Specifies whether encryption will be used for authenticated requests.
  14752. Defaults to @samp{Required}.
  14753. @end deftypevr
  14754. @deftypevr {@code{cups-configuration} parameter} string default-language
  14755. Specifies the default language to use for text and web content.
  14756. Defaults to @samp{"en"}.
  14757. @end deftypevr
  14758. @deftypevr {@code{cups-configuration} parameter} string default-paper-size
  14759. Specifies the default paper size for new print queues. @samp{"Auto"}
  14760. uses a locale-specific default, while @samp{"None"} specifies there is
  14761. no default paper size. Specific size names are typically
  14762. @samp{"Letter"} or @samp{"A4"}.
  14763. Defaults to @samp{"Auto"}.
  14764. @end deftypevr
  14765. @deftypevr {@code{cups-configuration} parameter} string default-policy
  14766. Specifies the default access policy to use.
  14767. Defaults to @samp{"default"}.
  14768. @end deftypevr
  14769. @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
  14770. Specifies whether local printers are shared by default.
  14771. Defaults to @samp{#t}.
  14772. @end deftypevr
  14773. @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
  14774. Specifies the delay for updating of configuration and state files, in
  14775. seconds. A value of 0 causes the update to happen as soon as possible,
  14776. typically within a few milliseconds.
  14777. Defaults to @samp{30}.
  14778. @end deftypevr
  14779. @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
  14780. Specifies what to do when an error occurs. Possible values are
  14781. @code{abort-job}, which will discard the failed print job;
  14782. @code{retry-job}, which will retry the job at a later time;
  14783. @code{retry-current-job}, which retries the failed job immediately; and
  14784. @code{stop-printer}, which stops the printer.
  14785. Defaults to @samp{stop-printer}.
  14786. @end deftypevr
  14787. @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
  14788. Specifies the maximum cost of filters that are run concurrently, which
  14789. can be used to minimize disk, memory, and CPU resource problems. A
  14790. limit of 0 disables filter limiting. An average print to a
  14791. non-PostScript printer needs a filter limit of about 200. A PostScript
  14792. printer needs about half that (100). Setting the limit below these
  14793. thresholds will effectively limit the scheduler to printing a single job
  14794. at any time.
  14795. Defaults to @samp{0}.
  14796. @end deftypevr
  14797. @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
  14798. Specifies the scheduling priority of filters that are run to print a
  14799. job. The nice value ranges from 0, the highest priority, to 19, the
  14800. lowest priority.
  14801. Defaults to @samp{0}.
  14802. @end deftypevr
  14803. @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
  14804. Specifies whether to do reverse lookups on connecting clients. The
  14805. @code{double} setting causes @code{cupsd} to verify that the hostname
  14806. resolved from the address matches one of the addresses returned for that
  14807. hostname. Double lookups also prevent clients with unregistered
  14808. addresses from connecting to your server. Only set this option to
  14809. @code{#t} or @code{double} if absolutely required.
  14810. Defaults to @samp{#f}.
  14811. @end deftypevr
  14812. @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
  14813. Specifies the number of seconds to wait before killing the filters and
  14814. backend associated with a canceled or held job.
  14815. Defaults to @samp{30}.
  14816. @end deftypevr
  14817. @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
  14818. Specifies the interval between retries of jobs in seconds. This is
  14819. typically used for fax queues but can also be used with normal print
  14820. queues whose error policy is @code{retry-job} or
  14821. @code{retry-current-job}.
  14822. Defaults to @samp{30}.
  14823. @end deftypevr
  14824. @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
  14825. Specifies the number of retries that are done for jobs. This is
  14826. typically used for fax queues but can also be used with normal print
  14827. queues whose error policy is @code{retry-job} or
  14828. @code{retry-current-job}.
  14829. Defaults to @samp{5}.
  14830. @end deftypevr
  14831. @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
  14832. Specifies whether to support HTTP keep-alive connections.
  14833. Defaults to @samp{#t}.
  14834. @end deftypevr
  14835. @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
  14836. Specifies how long an idle client connection remains open, in seconds.
  14837. Defaults to @samp{30}.
  14838. @end deftypevr
  14839. @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
  14840. Specifies the maximum size of print files, IPP requests, and HTML form
  14841. data. A limit of 0 disables the limit check.
  14842. Defaults to @samp{0}.
  14843. @end deftypevr
  14844. @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
  14845. Listens on the specified interfaces for connections. Valid values are
  14846. of the form @var{address}:@var{port}, where @var{address} is either an
  14847. IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
  14848. indicate all addresses. Values can also be file names of local UNIX
  14849. domain sockets. The Listen directive is similar to the Port directive
  14850. but allows you to restrict access to specific interfaces or networks.
  14851. @end deftypevr
  14852. @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
  14853. Specifies the number of pending connections that will be allowed. This
  14854. normally only affects very busy servers that have reached the MaxClients
  14855. limit, but can also be triggered by large numbers of simultaneous
  14856. connections. When the limit is reached, the operating system will
  14857. refuse additional connections until the scheduler can accept the pending
  14858. ones.
  14859. Defaults to @samp{128}.
  14860. @end deftypevr
  14861. @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
  14862. Specifies a set of additional access controls.
  14863. Available @code{location-access-controls} fields are:
  14864. @deftypevr {@code{location-access-controls} parameter} file-name path
  14865. Specifies the URI path to which the access control applies.
  14866. @end deftypevr
  14867. @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
  14868. Access controls for all access to this path, in the same format as the
  14869. @code{access-controls} of @code{operation-access-control}.
  14870. Defaults to @samp{()}.
  14871. @end deftypevr
  14872. @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
  14873. Access controls for method-specific access to this path.
  14874. Defaults to @samp{()}.
  14875. Available @code{method-access-controls} fields are:
  14876. @deftypevr {@code{method-access-controls} parameter} boolean reverse?
  14877. If @code{#t}, apply access controls to all methods except the listed
  14878. methods. Otherwise apply to only the listed methods.
  14879. Defaults to @samp{#f}.
  14880. @end deftypevr
  14881. @deftypevr {@code{method-access-controls} parameter} method-list methods
  14882. Methods to which this access control applies.
  14883. Defaults to @samp{()}.
  14884. @end deftypevr
  14885. @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
  14886. Access control directives, as a list of strings. Each string should be
  14887. one directive, such as @samp{"Order allow,deny"}.
  14888. Defaults to @samp{()}.
  14889. @end deftypevr
  14890. @end deftypevr
  14891. @end deftypevr
  14892. @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
  14893. Specifies the number of debugging messages that are retained for logging
  14894. if an error occurs in a print job. Debug messages are logged regardless
  14895. of the LogLevel setting.
  14896. Defaults to @samp{100}.
  14897. @end deftypevr
  14898. @deftypevr {@code{cups-configuration} parameter} log-level log-level
  14899. Specifies the level of logging for the ErrorLog file. The value
  14900. @code{none} stops all logging while @code{debug2} logs everything.
  14901. Defaults to @samp{info}.
  14902. @end deftypevr
  14903. @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
  14904. Specifies the format of the date and time in the log files. The value
  14905. @code{standard} logs whole seconds while @code{usecs} logs microseconds.
  14906. Defaults to @samp{standard}.
  14907. @end deftypevr
  14908. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
  14909. Specifies the maximum number of simultaneous clients that are allowed by
  14910. the scheduler.
  14911. Defaults to @samp{100}.
  14912. @end deftypevr
  14913. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
  14914. Specifies the maximum number of simultaneous clients that are allowed
  14915. from a single address.
  14916. Defaults to @samp{100}.
  14917. @end deftypevr
  14918. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
  14919. Specifies the maximum number of copies that a user can print of each
  14920. job.
  14921. Defaults to @samp{9999}.
  14922. @end deftypevr
  14923. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
  14924. Specifies the maximum time a job may remain in the @code{indefinite}
  14925. hold state before it is canceled. A value of 0 disables cancellation of
  14926. held jobs.
  14927. Defaults to @samp{0}.
  14928. @end deftypevr
  14929. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
  14930. Specifies the maximum number of simultaneous jobs that are allowed. Set
  14931. to 0 to allow an unlimited number of jobs.
  14932. Defaults to @samp{500}.
  14933. @end deftypevr
  14934. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
  14935. Specifies the maximum number of simultaneous jobs that are allowed per
  14936. printer. A value of 0 allows up to MaxJobs jobs per printer.
  14937. Defaults to @samp{0}.
  14938. @end deftypevr
  14939. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
  14940. Specifies the maximum number of simultaneous jobs that are allowed per
  14941. user. A value of 0 allows up to MaxJobs jobs per user.
  14942. Defaults to @samp{0}.
  14943. @end deftypevr
  14944. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
  14945. Specifies the maximum time a job may take to print before it is
  14946. canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
  14947. Defaults to @samp{10800}.
  14948. @end deftypevr
  14949. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
  14950. Specifies the maximum size of the log files before they are rotated, in
  14951. bytes. The value 0 disables log rotation.
  14952. Defaults to @samp{1048576}.
  14953. @end deftypevr
  14954. @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
  14955. Specifies the maximum amount of time to allow between files in a
  14956. multiple file print job, in seconds.
  14957. Defaults to @samp{300}.
  14958. @end deftypevr
  14959. @deftypevr {@code{cups-configuration} parameter} string page-log-format
  14960. Specifies the format of PageLog lines. Sequences beginning with percent
  14961. (@samp{%}) characters are replaced with the corresponding information,
  14962. while all other characters are copied literally. The following percent
  14963. sequences are recognized:
  14964. @table @samp
  14965. @item %%
  14966. insert a single percent character
  14967. @item %@{name@}
  14968. insert the value of the specified IPP attribute
  14969. @item %C
  14970. insert the number of copies for the current page
  14971. @item %P
  14972. insert the current page number
  14973. @item %T
  14974. insert the current date and time in common log format
  14975. @item %j
  14976. insert the job ID
  14977. @item %p
  14978. insert the printer name
  14979. @item %u
  14980. insert the username
  14981. @end table
  14982. A value of the empty string disables page logging. The string @code{%p
  14983. %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
  14984. %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
  14985. standard items.
  14986. Defaults to @samp{""}.
  14987. @end deftypevr
  14988. @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
  14989. Passes the specified environment variable(s) to child processes; a list
  14990. of strings.
  14991. Defaults to @samp{()}.
  14992. @end deftypevr
  14993. @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
  14994. Specifies named access control policies.
  14995. Available @code{policy-configuration} fields are:
  14996. @deftypevr {@code{policy-configuration} parameter} string name
  14997. Name of the policy.
  14998. @end deftypevr
  14999. @deftypevr {@code{policy-configuration} parameter} string job-private-access
  15000. Specifies an access list for a job's private values. @code{@@ACL} maps
  15001. to the printer's requesting-user-name-allowed or
  15002. requesting-user-name-denied values. @code{@@OWNER} maps to the job's
  15003. owner. @code{@@SYSTEM} maps to the groups listed for the
  15004. @code{system-group} field of the @code{files-config} configuration,
  15005. which is reified into the @code{cups-files.conf(5)} file. Other
  15006. possible elements of the access list include specific user names, and
  15007. @code{@@@var{group}} to indicate members of a specific group. The
  15008. access list may also be simply @code{all} or @code{default}.
  15009. Defaults to @samp{"@@OWNER @@SYSTEM"}.
  15010. @end deftypevr
  15011. @deftypevr {@code{policy-configuration} parameter} string job-private-values
  15012. Specifies the list of job values to make private, or @code{all},
  15013. @code{default}, or @code{none}.
  15014. Defaults to @samp{"job-name job-originating-host-name
  15015. job-originating-user-name phone"}.
  15016. @end deftypevr
  15017. @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
  15018. Specifies an access list for a subscription's private values.
  15019. @code{@@ACL} maps to the printer's requesting-user-name-allowed or
  15020. requesting-user-name-denied values. @code{@@OWNER} maps to the job's
  15021. owner. @code{@@SYSTEM} maps to the groups listed for the
  15022. @code{system-group} field of the @code{files-config} configuration,
  15023. which is reified into the @code{cups-files.conf(5)} file. Other
  15024. possible elements of the access list include specific user names, and
  15025. @code{@@@var{group}} to indicate members of a specific group. The
  15026. access list may also be simply @code{all} or @code{default}.
  15027. Defaults to @samp{"@@OWNER @@SYSTEM"}.
  15028. @end deftypevr
  15029. @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
  15030. Specifies the list of job values to make private, or @code{all},
  15031. @code{default}, or @code{none}.
  15032. Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
  15033. notify-subscriber-user-name notify-user-data"}.
  15034. @end deftypevr
  15035. @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
  15036. Access control by IPP operation.
  15037. Defaults to @samp{()}.
  15038. @end deftypevr
  15039. @end deftypevr
  15040. @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
  15041. Specifies whether job files (documents) are preserved after a job is
  15042. printed. If a numeric value is specified, job files are preserved for
  15043. the indicated number of seconds after printing. Otherwise a boolean
  15044. value applies indefinitely.
  15045. Defaults to @samp{86400}.
  15046. @end deftypevr
  15047. @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
  15048. Specifies whether the job history is preserved after a job is printed.
  15049. If a numeric value is specified, the job history is preserved for the
  15050. indicated number of seconds after printing. If @code{#t}, the job
  15051. history is preserved until the MaxJobs limit is reached.
  15052. Defaults to @samp{#t}.
  15053. @end deftypevr
  15054. @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
  15055. Specifies the amount of time to wait for job completion before
  15056. restarting the scheduler.
  15057. Defaults to @samp{30}.
  15058. @end deftypevr
  15059. @deftypevr {@code{cups-configuration} parameter} string rip-cache
  15060. Specifies the maximum amount of memory to use when converting documents
  15061. into bitmaps for a printer.
  15062. Defaults to @samp{"128m"}.
  15063. @end deftypevr
  15064. @deftypevr {@code{cups-configuration} parameter} string server-admin
  15065. Specifies the email address of the server administrator.
  15066. Defaults to @samp{"root@@localhost.localdomain"}.
  15067. @end deftypevr
  15068. @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
  15069. The ServerAlias directive is used for HTTP Host header validation when
  15070. clients connect to the scheduler from external interfaces. Using the
  15071. special name @code{*} can expose your system to known browser-based DNS
  15072. rebinding attacks, even when accessing sites through a firewall. If the
  15073. auto-discovery of alternate names does not work, we recommend listing
  15074. each alternate name with a ServerAlias directive instead of using
  15075. @code{*}.
  15076. Defaults to @samp{*}.
  15077. @end deftypevr
  15078. @deftypevr {@code{cups-configuration} parameter} string server-name
  15079. Specifies the fully-qualified host name of the server.
  15080. Defaults to @samp{"localhost"}.
  15081. @end deftypevr
  15082. @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
  15083. Specifies what information is included in the Server header of HTTP
  15084. responses. @code{None} disables the Server header. @code{ProductOnly}
  15085. reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
  15086. reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
  15087. @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
  15088. the output of the @code{uname} command. @code{Full} reports @code{CUPS
  15089. 2.0.0 (@var{uname}) IPP/2.0}.
  15090. Defaults to @samp{Minimal}.
  15091. @end deftypevr
  15092. @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
  15093. Listens on the specified interfaces for encrypted connections. Valid
  15094. values are of the form @var{address}:@var{port}, where @var{address} is
  15095. either an IPv6 address enclosed in brackets, an IPv4 address, or
  15096. @code{*} to indicate all addresses.
  15097. Defaults to @samp{()}.
  15098. @end deftypevr
  15099. @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
  15100. Sets encryption options. By default, CUPS only supports encryption
  15101. using TLS v1.0 or higher using known secure cipher suites. Security is
  15102. reduced when @code{Allow} options are used, and enhanced when @code{Deny}
  15103. options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
  15104. suites, which are required for some older clients. The @code{AllowSSL3} option
  15105. enables SSL v3.0, which is required for some older clients that do not support
  15106. TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
  15107. @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
  15108. protocol version to TLS v1.1.
  15109. Defaults to @samp{()}.
  15110. @end deftypevr
  15111. @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
  15112. Specifies whether the scheduler requires clients to strictly adhere to
  15113. the IPP specifications.
  15114. Defaults to @samp{#f}.
  15115. @end deftypevr
  15116. @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
  15117. Specifies the HTTP request timeout, in seconds.
  15118. Defaults to @samp{300}.
  15119. @end deftypevr
  15120. @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
  15121. Specifies whether the web interface is enabled.
  15122. Defaults to @samp{#f}.
  15123. @end deftypevr
  15124. At this point you're probably thinking ``oh dear, Guix manual, I like
  15125. you but you can stop already with the configuration options''. Indeed.
  15126. However, one more point: it could be that you have an existing
  15127. @code{cupsd.conf} that you want to use. In that case, you can pass an
  15128. @code{opaque-cups-configuration} as the configuration of a
  15129. @code{cups-service-type}.
  15130. Available @code{opaque-cups-configuration} fields are:
  15131. @deftypevr {@code{opaque-cups-configuration} parameter} package cups
  15132. The CUPS package.
  15133. @end deftypevr
  15134. @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
  15135. The contents of the @code{cupsd.conf}, as a string.
  15136. @end deftypevr
  15137. @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
  15138. The contents of the @code{cups-files.conf} file, as a string.
  15139. @end deftypevr
  15140. For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
  15141. strings of the same name, you could instantiate a CUPS service like
  15142. this:
  15143. @lisp
  15144. (service cups-service-type
  15145. (opaque-cups-configuration
  15146. (cupsd.conf cupsd.conf)
  15147. (cups-files.conf cups-files.conf)))
  15148. @end lisp
  15149. @node Desktop Services
  15150. @subsection Desktop Services
  15151. The @code{(gnu services desktop)} module provides services that are
  15152. usually useful in the context of a ``desktop'' setup---that is, on a
  15153. machine running a graphical display server, possibly with graphical user
  15154. interfaces, etc. It also defines services that provide specific desktop
  15155. environments like GNOME, Xfce or MATE.
  15156. To simplify things, the module defines a variable containing the set of
  15157. services that users typically expect on a machine with a graphical
  15158. environment and networking:
  15159. @defvr {Scheme Variable} %desktop-services
  15160. This is a list of services that builds upon @code{%base-services} and
  15161. adds or adjusts services for a typical ``desktop'' setup.
  15162. In particular, it adds a graphical login manager (@pxref{X Window,
  15163. @code{gdm-service-type}}), screen lockers, a network management tool
  15164. (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
  15165. support (@pxref{Networking Services, @code{modem-manager-service-type}}),
  15166. energy and color management services, the @code{elogind} login and seat
  15167. manager, the Polkit privilege service, the GeoClue location service, the
  15168. AccountsService daemon that allows authorized users change system passwords,
  15169. an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
  15170. name service switch service configured to be able to use @code{nss-mdns}
  15171. (@pxref{Name Service Switch, mDNS}).
  15172. @end defvr
  15173. The @code{%desktop-services} variable can be used as the @code{services}
  15174. field of an @code{operating-system} declaration (@pxref{operating-system
  15175. Reference, @code{services}}).
  15176. Additionally, the @code{gnome-desktop-service-type},
  15177. @code{xfce-desktop-service}, @code{mate-desktop-service-type},
  15178. @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
  15179. procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
  15180. ``add GNOME'' means that system-level services like the backlight adjustment
  15181. helpers and the power management utilities are added to the system, extending
  15182. @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
  15183. elevated privileges on a limited number of special-purpose system interfaces.
  15184. Additionally, adding a service made by @code{gnome-desktop-service-type} adds
  15185. the GNOME metapackage to the system profile. Likewise, adding the Xfce
  15186. service not only adds the @code{xfce} metapackage to the system profile, but
  15187. it also gives the Thunar file manager the ability to open a ``root-mode'' file
  15188. management window, if the user authenticates using the administrator's
  15189. password via the standard polkit graphical interface. To ``add MATE'' means
  15190. that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
  15191. to operate with elevated privileges on a limited number of special-purpose
  15192. system interfaces. Additionally, adding a service of type
  15193. @code{mate-desktop-service-type} adds the MATE metapackage to the system
  15194. profile. ``Adding Enlightenment'' means that @code{dbus} is extended
  15195. appropriately, and several of Enlightenment's binaries are set as setuid,
  15196. allowing Enlightenment's screen locker and other functionality to work as
  15197. expected.
  15198. The desktop environments in Guix use the Xorg display server by
  15199. default. If you'd like to use the newer display server protocol
  15200. called Wayland, you need to use the @code{sddm-service} instead of
  15201. GDM as the graphical login manager. You should then
  15202. select the ``GNOME (Wayland)'' session in SDDM@. Alternatively you can
  15203. also try starting GNOME on Wayland manually from a TTY with the
  15204. command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
  15205. gnome-session``. Currently only GNOME has support for Wayland.
  15206. @defvr {Scheme Variable} gnome-desktop-service-type
  15207. This is the type of the service that adds the @uref{https://www.gnome.org,
  15208. GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
  15209. object (see below).
  15210. This service adds the @code{gnome} package to the system profile, and extends
  15211. polkit with the actions from @code{gnome-settings-daemon}.
  15212. @end defvr
  15213. @deftp {Data Type} gnome-desktop-configuration
  15214. Configuration record for the GNOME desktop environment.
  15215. @table @asis
  15216. @item @code{gnome} (default: @code{gnome})
  15217. The GNOME package to use.
  15218. @end table
  15219. @end deftp
  15220. @defvr {Scheme Variable} xfce-desktop-service-type
  15221. This is the type of a service to run the @uref{Xfce, https://xfce.org/}
  15222. desktop environment. Its value is an @code{xfce-desktop-configuration} object
  15223. (see below).
  15224. This service adds the @code{xfce} package to the system profile, and
  15225. extends polkit with the ability for @code{thunar} to manipulate the file
  15226. system as root from within a user session, after the user has authenticated
  15227. with the administrator's password.
  15228. Note that @code{xfce4-panel} and its plugin packages should be installed in
  15229. the same profile to ensure compatibility. When using this service, you should
  15230. add extra plugins (@code{xfce4-whiskermenu-plugin},
  15231. @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
  15232. @code{operating-system}.
  15233. @end defvr
  15234. @deftp {Data Type} xfce-desktop-configuration
  15235. Configuration record for the Xfce desktop environment.
  15236. @table @asis
  15237. @item @code{xfce} (default: @code{xfce})
  15238. The Xfce package to use.
  15239. @end table
  15240. @end deftp
  15241. @deffn {Scheme Variable} mate-desktop-service-type
  15242. This is the type of the service that runs the @uref{https://mate-desktop.org/,
  15243. MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
  15244. object (see below).
  15245. This service adds the @code{mate} package to the system
  15246. profile, and extends polkit with the actions from
  15247. @code{mate-settings-daemon}.
  15248. @end deffn
  15249. @deftp {Data Type} mate-desktop-configuration
  15250. Configuration record for the MATE desktop environment.
  15251. @table @asis
  15252. @item @code{mate} (default: @code{mate})
  15253. The MATE package to use.
  15254. @end table
  15255. @end deftp
  15256. @deffn {Scheme Variable} lxqt-desktop-service-type
  15257. This is the type of the service that runs the @uref{https://lxqt.github.io,
  15258. LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
  15259. object (see below).
  15260. This service adds the @code{lxqt} package to the system
  15261. profile.
  15262. @end deffn
  15263. @deftp {Data Type} lxqt-desktop-configuration
  15264. Configuration record for the LXQt desktop environment.
  15265. @table @asis
  15266. @item @code{lxqt} (default: @code{lxqt})
  15267. The LXQT package to use.
  15268. @end table
  15269. @end deftp
  15270. @deffn {Scheme Variable} enlightenment-desktop-service-type
  15271. Return a service that adds the @code{enlightenment} package to the system
  15272. profile, and extends dbus with actions from @code{efl}.
  15273. @end deffn
  15274. @deftp {Data Type} enlightenment-desktop-service-configuration
  15275. @table @asis
  15276. @item @code{enlightenment} (default: @code{enlightenment})
  15277. The enlightenment package to use.
  15278. @end table
  15279. @end deftp
  15280. Because the GNOME, Xfce and MATE desktop services pull in so many packages,
  15281. the default @code{%desktop-services} variable doesn't include any of
  15282. them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
  15283. @code{%desktop-services} in the @code{services} field of your
  15284. @code{operating-system}:
  15285. @lisp
  15286. (use-modules (gnu))
  15287. (use-service-modules desktop)
  15288. (operating-system
  15289. ...
  15290. ;; cons* adds items to the list given as its last argument.
  15291. (services (cons* (service gnome-desktop-service-type)
  15292. (service xfce-desktop-service)
  15293. %desktop-services))
  15294. ...)
  15295. @end lisp
  15296. These desktop environments will then be available as options in the
  15297. graphical login window.
  15298. The actual service definitions included in @code{%desktop-services} and
  15299. provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
  15300. are described below.
  15301. @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
  15302. Return a service that runs the ``system bus'', using @var{dbus}, with
  15303. support for @var{services}.
  15304. @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
  15305. facility. Its system bus is used to allow system services to communicate
  15306. and to be notified of system-wide events.
  15307. @var{services} must be a list of packages that provide an
  15308. @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
  15309. and policy files. For example, to allow avahi-daemon to use the system bus,
  15310. @var{services} must be equal to @code{(list avahi)}.
  15311. @end deffn
  15312. @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
  15313. Return a service that runs the @code{elogind} login and
  15314. seat management daemon. @uref{https://github.com/elogind/elogind,
  15315. Elogind} exposes a D-Bus interface that can be used to know which users
  15316. are logged in, know what kind of sessions they have open, suspend the
  15317. system, inhibit system suspend, reboot the system, and other tasks.
  15318. Elogind handles most system-level power events for a computer, for
  15319. example suspending the system when a lid is closed, or shutting it down
  15320. when the power button is pressed.
  15321. The @var{config} keyword argument specifies the configuration for
  15322. elogind, and should be the result of an @code{(elogind-configuration
  15323. (@var{parameter} @var{value})...)} invocation. Available parameters and
  15324. their default values are:
  15325. @table @code
  15326. @item kill-user-processes?
  15327. @code{#f}
  15328. @item kill-only-users
  15329. @code{()}
  15330. @item kill-exclude-users
  15331. @code{("root")}
  15332. @item inhibit-delay-max-seconds
  15333. @code{5}
  15334. @item handle-power-key
  15335. @code{poweroff}
  15336. @item handle-suspend-key
  15337. @code{suspend}
  15338. @item handle-hibernate-key
  15339. @code{hibernate}
  15340. @item handle-lid-switch
  15341. @code{suspend}
  15342. @item handle-lid-switch-docked
  15343. @code{ignore}
  15344. @item handle-lid-switch-external-power
  15345. @code{ignore}
  15346. @item power-key-ignore-inhibited?
  15347. @code{#f}
  15348. @item suspend-key-ignore-inhibited?
  15349. @code{#f}
  15350. @item hibernate-key-ignore-inhibited?
  15351. @code{#f}
  15352. @item lid-switch-ignore-inhibited?
  15353. @code{#t}
  15354. @item holdoff-timeout-seconds
  15355. @code{30}
  15356. @item idle-action
  15357. @code{ignore}
  15358. @item idle-action-seconds
  15359. @code{(* 30 60)}
  15360. @item runtime-directory-size-percent
  15361. @code{10}
  15362. @item runtime-directory-size
  15363. @code{#f}
  15364. @item remove-ipc?
  15365. @code{#t}
  15366. @item suspend-state
  15367. @code{("mem" "standby" "freeze")}
  15368. @item suspend-mode
  15369. @code{()}
  15370. @item hibernate-state
  15371. @code{("disk")}
  15372. @item hibernate-mode
  15373. @code{("platform" "shutdown")}
  15374. @item hybrid-sleep-state
  15375. @code{("disk")}
  15376. @item hybrid-sleep-mode
  15377. @code{("suspend" "platform" "shutdown")}
  15378. @end table
  15379. @end deffn
  15380. @deffn {Scheme Procedure} accountsservice-service @
  15381. [#:accountsservice @var{accountsservice}]
  15382. Return a service that runs AccountsService, a system service that can
  15383. list available accounts, change their passwords, and so on.
  15384. AccountsService integrates with PolicyKit to enable unprivileged users
  15385. to acquire the capability to modify their system configuration.
  15386. @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
  15387. accountsservice web site} for more information.
  15388. The @var{accountsservice} keyword argument is the @code{accountsservice}
  15389. package to expose as a service.
  15390. @end deffn
  15391. @deffn {Scheme Procedure} polkit-service @
  15392. [#:polkit @var{polkit}]
  15393. Return a service that runs the
  15394. @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
  15395. management service}, which allows system administrators to grant access to
  15396. privileged operations in a structured way. By querying the Polkit service, a
  15397. privileged system component can know when it should grant additional
  15398. capabilities to ordinary users. For example, an ordinary user can be granted
  15399. the capability to suspend the system if the user is logged in locally.
  15400. @end deffn
  15401. @defvr {Scheme Variable} polkit-wheel-service
  15402. Service that adds the @code{wheel} group as admins to the Polkit
  15403. service. This makes it so that users in the @code{wheel} group are queried
  15404. for their own passwords when performing administrative actions instead of
  15405. @code{root}'s, similar to the behaviour used by @code{sudo}.
  15406. @end defvr
  15407. @defvr {Scheme Variable} upower-service-type
  15408. Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
  15409. system-wide monitor for power consumption and battery levels, with the given
  15410. configuration settings.
  15411. It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
  15412. notably used by GNOME.
  15413. @end defvr
  15414. @deftp {Data Type} upower-configuration
  15415. Data type representation the configuration for UPower.
  15416. @table @asis
  15417. @item @code{upower} (default: @var{upower})
  15418. Package to use for @code{upower}.
  15419. @item @code{watts-up-pro?} (default: @code{#f})
  15420. Enable the Watts Up Pro device.
  15421. @item @code{poll-batteries?} (default: @code{#t})
  15422. Enable polling the kernel for battery level changes.
  15423. @item @code{ignore-lid?} (default: @code{#f})
  15424. Ignore the lid state, this can be useful if it's incorrect on a device.
  15425. @item @code{use-percentage-for-policy?} (default: @code{#f})
  15426. Whether battery percentage based policy should be used. The default is to use
  15427. the time left, change to @code{#t} to use the percentage.
  15428. @item @code{percentage-low} (default: @code{10})
  15429. When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
  15430. at which the battery is considered low.
  15431. @item @code{percentage-critical} (default: @code{3})
  15432. When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
  15433. at which the battery is considered critical.
  15434. @item @code{percentage-action} (default: @code{2})
  15435. When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
  15436. at which action will be taken.
  15437. @item @code{time-low} (default: @code{1200})
  15438. When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
  15439. seconds at which the battery is considered low.
  15440. @item @code{time-critical} (default: @code{300})
  15441. When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
  15442. seconds at which the battery is considered critical.
  15443. @item @code{time-action} (default: @code{120})
  15444. When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
  15445. seconds at which action will be taken.
  15446. @item @code{critical-power-action} (default: @code{'hybrid-sleep})
  15447. The action taken when @code{percentage-action} or @code{time-action} is
  15448. reached (depending on the configuration of @code{use-percentage-for-policy?}).
  15449. Possible values are:
  15450. @itemize @bullet
  15451. @item
  15452. @code{'power-off}
  15453. @item
  15454. @code{'hibernate}
  15455. @item
  15456. @code{'hybrid-sleep}.
  15457. @end itemize
  15458. @end table
  15459. @end deftp
  15460. @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
  15461. Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
  15462. UDisks}, a @dfn{disk management} daemon that provides user interfaces
  15463. with notifications and ways to mount/unmount disks. Programs that talk
  15464. to UDisks include the @command{udisksctl} command, part of UDisks, and
  15465. GNOME Disks. Note that Udisks relies on the @command{mount} command, so
  15466. it will only be able to use the file-system utilities installed in the
  15467. system profile. For example if you want to be able to mount NTFS
  15468. file-systems in read and write fashion, you'll need to have
  15469. @code{ntfs-3g} installed system-wide.
  15470. @end deffn
  15471. @deffn {Scheme Variable} colord-service-type
  15472. This is the type of the service that runs @command{colord}, a system
  15473. service with a D-Bus
  15474. interface to manage the color profiles of input and output devices such as
  15475. screens and scanners. It is notably used by the GNOME Color Manager graphical
  15476. tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
  15477. site} for more information.
  15478. @end deffn
  15479. @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
  15480. Return a configuration allowing an application to access GeoClue
  15481. location data. @var{name} is the Desktop ID of the application, without
  15482. the @code{.desktop} part. If @var{allowed?} is true, the application
  15483. will have access to location information by default. The boolean
  15484. @var{system?} value indicates whether an application is a system component
  15485. or not. Finally @var{users} is a list of UIDs of all users for which
  15486. this application is allowed location info access. An empty users list
  15487. means that all users are allowed.
  15488. @end deffn
  15489. @cindex scanner access
  15490. @deffn {Scheme Procedure} sane-service-type
  15491. This service provides access to scanners @i{via}
  15492. @uref{http://www.sane-project.org, SANE} by installing the necessary udev
  15493. rules.
  15494. @end deffn
  15495. @defvr {Scheme Variable} %standard-geoclue-applications
  15496. The standard list of well-known GeoClue application configurations,
  15497. granting authority to the GNOME date-and-time utility to ask for the
  15498. current location in order to set the time zone, and allowing the
  15499. IceCat and Epiphany web browsers to request location information.
  15500. IceCat and Epiphany both query the user before allowing a web page to
  15501. know the user's location.
  15502. @end defvr
  15503. @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
  15504. [#:whitelist '()] @
  15505. [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
  15506. [#:submit-data? #f]
  15507. [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
  15508. [#:submission-nick "geoclue"] @
  15509. [#:applications %standard-geoclue-applications]
  15510. Return a service that runs the GeoClue location service. This service
  15511. provides a D-Bus interface to allow applications to request access to a
  15512. user's physical location, and optionally to add information to online
  15513. location databases. See
  15514. @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
  15515. web site} for more information.
  15516. @end deffn
  15517. @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
  15518. [@w{#:auto-enable? #f}]
  15519. Return a service that runs the @command{bluetoothd} daemon, which
  15520. manages all the Bluetooth devices and provides a number of D-Bus
  15521. interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
  15522. powered automatically at boot, which can be useful when using a
  15523. bluetooth keyboard or mouse.
  15524. Users need to be in the @code{lp} group to access the D-Bus service.
  15525. @end deffn
  15526. @defvr {Scheme Variable} gnome-keyring-service-type
  15527. This is the type of the service that adds the
  15528. @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
  15529. value is a @code{gnome-keyring-configuration} object (see below).
  15530. This service adds the @code{gnome-keyring} package to the system profile
  15531. and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
  15532. a user's login keyring when they log in or setting its password with passwd.
  15533. @end defvr
  15534. @deftp {Data Type} gnome-keyring-configuration
  15535. Configuration record for the GNOME Keyring service.
  15536. @table @asis
  15537. @item @code{keyring} (default: @code{gnome-keyring})
  15538. The GNOME keyring package to use.
  15539. @item @code{pam-services}
  15540. A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
  15541. services to extend, where @var{service} is the name of an existing
  15542. service to extend and @var{kind} is one of @code{login} or
  15543. @code{passwd}.
  15544. If @code{login} is given, it adds an optional
  15545. @code{pam_gnome_keyring.so} to the auth block without arguments and to
  15546. the session block with @code{auto_start}. If @code{passwd} is given, it
  15547. adds an optional @code{pam_gnome_keyring.so} to the password block
  15548. without arguments.
  15549. By default, this field contains ``gdm-password'' with the value @code{login}
  15550. and ``passwd'' is with the value @code{passwd}.
  15551. @end table
  15552. @end deftp
  15553. @node Sound Services
  15554. @subsection Sound Services
  15555. @cindex sound support
  15556. @cindex ALSA
  15557. @cindex PulseAudio, sound support
  15558. The @code{(gnu services sound)} module provides a service to configure the
  15559. Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
  15560. preferred ALSA output driver.
  15561. @deffn {Scheme Variable} alsa-service-type
  15562. This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
  15563. Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
  15564. configuration file. The value for this type is a @command{alsa-configuration}
  15565. record as in this example:
  15566. @lisp
  15567. (service alsa-service-type)
  15568. @end lisp
  15569. See below for details about @code{alsa-configuration}.
  15570. @end deffn
  15571. @deftp {Data Type} alsa-configuration
  15572. Data type representing the configuration for @code{alsa-service}.
  15573. @table @asis
  15574. @item @code{alsa-plugins} (default: @var{alsa-plugins})
  15575. @code{alsa-plugins} package to use.
  15576. @item @code{pulseaudio?} (default: @var{#t})
  15577. Whether ALSA applications should transparently be made to use the
  15578. @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
  15579. Using PulseAudio allows you to run several sound-producing applications
  15580. at the same time and to individual control them @i{via}
  15581. @command{pavucontrol}, among other things.
  15582. @item @code{extra-options} (default: @var{""})
  15583. String to append to the @file{/etc/asound.conf} file.
  15584. @end table
  15585. @end deftp
  15586. Individual users who want to override the system configuration of ALSA can do
  15587. it with the @file{~/.asoundrc} file:
  15588. @example
  15589. # In guix, we have to specify the absolute path for plugins.
  15590. pcm_type.jack @{
  15591. lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
  15592. @}
  15593. # Routing ALSA to jack:
  15594. # <http://jackaudio.org/faq/routing_alsa.html>.
  15595. pcm.rawjack @{
  15596. type jack
  15597. playback_ports @{
  15598. 0 system:playback_1
  15599. 1 system:playback_2
  15600. @}
  15601. capture_ports @{
  15602. 0 system:capture_1
  15603. 1 system:capture_2
  15604. @}
  15605. @}
  15606. pcm.!default @{
  15607. type plug
  15608. slave @{
  15609. pcm "rawjack"
  15610. @}
  15611. @}
  15612. @end example
  15613. See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
  15614. details.
  15615. @deffn {Scheme Variable} pulseaudio-service-type
  15616. This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
  15617. sound server. It exists to allow system overrides of the default settings
  15618. via @code{pulseaudio-configuration}, see below.
  15619. @quotation Warning
  15620. This service overrides per-user configuration files. If you want
  15621. PulseAudio to honor configuration files in @file{~/.config/pulse} you
  15622. have to unset the environment variables @env{PULSE_CONFIG} and
  15623. @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
  15624. @end quotation
  15625. @quotation Warning
  15626. This service on its own does not ensure, that the @code{pulseaudio} package
  15627. exists on your machine. It merely adds configuration files for it, as
  15628. detailed below. In the (admittedly unlikely) case, that you find yourself
  15629. without a @code{pulseaudio} package, consider enabling it through the
  15630. @code{alsa-service-type} above.
  15631. @end quotation
  15632. @end deffn
  15633. @deftp {Data Type} pulseaudio-configuration
  15634. Data type representing the configuration for @code{pulseaudio-service}.
  15635. @table @asis
  15636. @item @code{client-conf} (default: @code{'()})
  15637. List of settings to set in @file{client.conf}.
  15638. Accepts a list of strings or a symbol-value pairs. A string will be
  15639. inserted as-is with a newline added. A pair will be formatted as
  15640. ``key = value'', again with a newline added.
  15641. @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
  15642. List of settings to set in @file{daemon.conf}, formatted just like
  15643. @var{client-conf}.
  15644. @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
  15645. Script file to use as @file{default.pa}.
  15646. @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
  15647. Script file to use as @file{system.pa}.
  15648. @end table
  15649. @end deftp
  15650. @deffn {Scheme Variable} ladspa-service-type
  15651. This service sets the @var{LADSPA_PATH} variable, so that programs, which
  15652. respect it, e.g. PulseAudio, can load LADSPA plugins.
  15653. The following example will setup the service to enable modules from the
  15654. @code{swh-plugins} package:
  15655. @lisp
  15656. (service ladspa-service-type
  15657. (ladspa-configuration (plugins (list swh-plugins))))
  15658. @end lisp
  15659. See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
  15660. details.
  15661. @end deffn
  15662. @node Database Services
  15663. @subsection Database Services
  15664. @cindex database
  15665. @cindex SQL
  15666. The @code{(gnu services databases)} module provides the following services.
  15667. @subsubheading PostgreSQL
  15668. The following example describes a PostgreSQL service with the default
  15669. configuration.
  15670. @lisp
  15671. (service postgresql-service-type
  15672. (postgresql-configuration
  15673. (postgresql postgresql-10)))
  15674. @end lisp
  15675. If the services fails to start, it may be due to an incompatible
  15676. cluster already present in @var{data-directory}. Adjust it (or, if you
  15677. don't need the cluster anymore, delete @var{data-directory}), then
  15678. restart the service.
  15679. Peer authentication is used by default and the @code{postgres} user
  15680. account has no shell, which prevents the direct execution of @code{psql}
  15681. commands as this user. To use @code{psql}, you can temporarily log in
  15682. as @code{postgres} using a shell, create a PostgreSQL superuser with the
  15683. same name as one of the system users and then create the associated
  15684. database.
  15685. @example
  15686. sudo -u postgres -s /bin/sh
  15687. createuser --interactive
  15688. createdb $MY_USER_LOGIN # Replace appropriately.
  15689. @end example
  15690. @deftp {Data Type} postgresql-configuration
  15691. Data type representing the configuration for the
  15692. @code{postgresql-service-type}.
  15693. @table @asis
  15694. @item @code{postgresql}
  15695. PostgreSQL package to use for the service.
  15696. @item @code{port} (default: @code{5432})
  15697. Port on which PostgreSQL should listen.
  15698. @item @code{locale} (default: @code{"en_US.utf8"})
  15699. Locale to use as the default when creating the database cluster.
  15700. @item @code{config-file} (default: @code{(postgresql-config-file)})
  15701. The configuration file to use when running PostgreSQL@. The default
  15702. behaviour uses the postgresql-config-file record with the default values
  15703. for the fields.
  15704. @item @code{log-directory} (default: @code{"/var/log/postgresql"})
  15705. The directory where @command{pg_ctl} output will be written in a file
  15706. named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
  15707. configuration errors for instance.
  15708. @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
  15709. Directory in which to store the data.
  15710. @item @code{extension-packages} (default: @code{'()})
  15711. @cindex postgresql extension-packages
  15712. Additional extensions are loaded from packages listed in
  15713. @var{extension-packages}. Extensions are available at runtime. For instance,
  15714. to create a geographic database using the @code{postgis} extension, a user can
  15715. configure the postgresql-service as in this example:
  15716. @cindex postgis
  15717. @lisp
  15718. (use-package-modules databases geo)
  15719. (operating-system
  15720. ...
  15721. ;; postgresql is required to run `psql' but postgis is not required for
  15722. ;; proper operation.
  15723. (packages (cons* postgresql %base-packages))
  15724. (services
  15725. (cons*
  15726. (service postgresql-service-type
  15727. (postgresql-configuration
  15728. (postgresql postgresql-10)
  15729. (extension-packages (list postgis))))
  15730. %base-services)))
  15731. @end lisp
  15732. Then the extension becomes visible and you can initialise an empty geographic
  15733. database in this way:
  15734. @example
  15735. psql -U postgres
  15736. > create database postgistest;
  15737. > \connect postgistest;
  15738. > create extension postgis;
  15739. > create extension postgis_topology;
  15740. @end example
  15741. There is no need to add this field for contrib extensions such as hstore or
  15742. dblink as they are already loadable by postgresql. This field is only
  15743. required to add extensions provided by other packages.
  15744. @end table
  15745. @end deftp
  15746. @deftp {Data Type} postgresql-config-file
  15747. Data type representing the PostgreSQL configuration file. As shown in
  15748. the following example, this can be used to customize the configuration
  15749. of PostgreSQL@. Note that you can use any G-expression or filename in
  15750. place of this record, if you already have a configuration file you'd
  15751. like to use for example.
  15752. @lisp
  15753. (service postgresql-service-type
  15754. (postgresql-configuration
  15755. (config-file
  15756. (postgresql-config-file
  15757. (log-destination "stderr")
  15758. (hba-file
  15759. (plain-file "pg_hba.conf"
  15760. "
  15761. local all all trust
  15762. host all all 127.0.0.1/32 md5
  15763. host all all ::1/128 md5"))
  15764. (extra-config
  15765. '(("session_preload_libraries" "auto_explain")
  15766. ("random_page_cost" 2)
  15767. ("auto_explain.log_min_duration" "100 ms")
  15768. ("work_mem" "500 MB")
  15769. ("logging_collector" #t)
  15770. ("log_directory" "/var/log/postgresql")))))))
  15771. @end lisp
  15772. @table @asis
  15773. @item @code{log-destination} (default: @code{"syslog"})
  15774. The logging method to use for PostgreSQL@. Multiple values are accepted,
  15775. separated by commas.
  15776. @item @code{hba-file} (default: @code{%default-postgres-hba})
  15777. Filename or G-expression for the host-based authentication
  15778. configuration.
  15779. @item @code{ident-file} (default: @code{%default-postgres-ident})
  15780. Filename or G-expression for the user name mapping configuration.
  15781. @item @code{socket-directory} (default: @code{"/var/run/postgresql"})
  15782. Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
  15783. is to listen for connections from client applications. If set to
  15784. @code{#false} PostgreSQL does not listen on any Unix-domain sockets, in
  15785. which case only TCP/IP sockets can be used to connect to the server.
  15786. @item @code{extra-config} (default: @code{'()})
  15787. List of additional keys and values to include in the PostgreSQL config
  15788. file. Each entry in the list should be a list where the first element
  15789. is the key, and the remaining elements are the values.
  15790. The values can be numbers, booleans or strings and will be mapped to
  15791. PostgreSQL parameters types @code{Boolean}, @code{String},
  15792. @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
  15793. @uref{https://www.postgresql.org/docs/current/config-setting.html,
  15794. here}.
  15795. @end table
  15796. @end deftp
  15797. @deffn {Scheme Variable} postgresql-role-service-type
  15798. This service allows to create PostgreSQL roles and databases after
  15799. PostgreSQL service start. Here is an example of its use.
  15800. @lisp
  15801. (service postgresql-role-service-type
  15802. (postgresql-role-configuration
  15803. (roles
  15804. (list (postgresql-role
  15805. (name "test")
  15806. (create-database? #t))))))
  15807. @end lisp
  15808. This service can be extended with extra roles, as in this
  15809. example:
  15810. @lisp
  15811. (service-extension postgresql-role-service-type
  15812. (const (postgresql-role
  15813. (name "alice")
  15814. (create-database? #t))))
  15815. @end lisp
  15816. @end deffn
  15817. @deftp {Data Type} postgresql-role
  15818. PostgreSQL manages database access permissions using the concept of
  15819. roles. A role can be thought of as either a database user, or a group
  15820. of database users, depending on how the role is set up. Roles can own
  15821. database objects (for example, tables) and can assign privileges on
  15822. those objects to other roles to control who has access to which objects.
  15823. @table @asis
  15824. @item @code{name}
  15825. The role name.
  15826. @item @code{permissions} (default: @code{'(createdb login)})
  15827. The role permissions list. Supported permissions are @code{bypassrls},
  15828. @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
  15829. @code{superuser}.
  15830. @item @code{create-database?} (default: @code{#f})
  15831. Whether to create a database with the same name as the role.
  15832. @end table
  15833. @end deftp
  15834. @deftp {Data Type} postgresql-role-configuration
  15835. Data type representing the configuration of
  15836. @var{postgresql-role-service-type}.
  15837. @table @asis
  15838. @item @code{host} (default: @code{"/var/run/postgresql"})
  15839. The PostgreSQL host to connect to.
  15840. @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
  15841. File name of the log file.
  15842. @item @code{roles} (default: @code{'()})
  15843. The initial PostgreSQL roles to create.
  15844. @end table
  15845. @end deftp
  15846. @subsubheading MariaDB/MySQL
  15847. @defvr {Scheme Variable} mysql-service-type
  15848. This is the service type for a MySQL or MariaDB database server. Its value
  15849. is a @code{mysql-configuration} object that specifies which package to use,
  15850. as well as various settings for the @command{mysqld} daemon.
  15851. @end defvr
  15852. @deftp {Data Type} mysql-configuration
  15853. Data type representing the configuration of @var{mysql-service-type}.
  15854. @table @asis
  15855. @item @code{mysql} (default: @var{mariadb})
  15856. Package object of the MySQL database server, can be either @var{mariadb}
  15857. or @var{mysql}.
  15858. For MySQL, a temporary root password will be displayed at activation time.
  15859. For MariaDB, the root password is empty.
  15860. @item @code{bind-address} (default: @code{"127.0.0.1"})
  15861. The IP on which to listen for network connections. Use @code{"0.0.0.0"}
  15862. to bind to all available network interfaces.
  15863. @item @code{port} (default: @code{3306})
  15864. TCP port on which the database server listens for incoming connections.
  15865. @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
  15866. Socket file to use for local (non-network) connections.
  15867. @item @code{extra-content} (default: @code{""})
  15868. Additional settings for the @file{my.cnf} configuration file.
  15869. @item @code{auto-upgrade?} (default: @code{#t})
  15870. Whether to automatically run @command{mysql_upgrade} after starting the
  15871. service. This is necessary to upgrade the @dfn{system schema} after
  15872. ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
  15873. be disabled if you would rather do that manually.
  15874. @end table
  15875. @end deftp
  15876. @subsubheading Memcached
  15877. @defvr {Scheme Variable} memcached-service-type
  15878. This is the service type for the @uref{https://memcached.org/,
  15879. Memcached} service, which provides a distributed in memory cache. The
  15880. value for the service type is a @code{memcached-configuration} object.
  15881. @end defvr
  15882. @lisp
  15883. (service memcached-service-type)
  15884. @end lisp
  15885. @deftp {Data Type} memcached-configuration
  15886. Data type representing the configuration of memcached.
  15887. @table @asis
  15888. @item @code{memcached} (default: @code{memcached})
  15889. The Memcached package to use.
  15890. @item @code{interfaces} (default: @code{'("0.0.0.0")})
  15891. Network interfaces on which to listen.
  15892. @item @code{tcp-port} (default: @code{11211})
  15893. Port on which to accept connections.
  15894. @item @code{udp-port} (default: @code{11211})
  15895. Port on which to accept UDP connections on, a value of 0 will disable
  15896. listening on a UDP socket.
  15897. @item @code{additional-options} (default: @code{'()})
  15898. Additional command line options to pass to @code{memcached}.
  15899. @end table
  15900. @end deftp
  15901. @subsubheading MongoDB
  15902. @defvr {Scheme Variable} mongodb-service-type
  15903. This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
  15904. The value for the service type is a @code{mongodb-configuration} object.
  15905. @end defvr
  15906. @lisp
  15907. (service mongodb-service-type)
  15908. @end lisp
  15909. @deftp {Data Type} mongodb-configuration
  15910. Data type representing the configuration of mongodb.
  15911. @table @asis
  15912. @item @code{mongodb} (default: @code{mongodb})
  15913. The MongoDB package to use.
  15914. @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
  15915. The configuration file for MongoDB.
  15916. @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
  15917. This value is used to create the directory, so that it exists and is
  15918. owned by the mongodb user. It should match the data-directory which
  15919. MongoDB is configured to use through the configuration file.
  15920. @end table
  15921. @end deftp
  15922. @subsubheading Redis
  15923. @defvr {Scheme Variable} redis-service-type
  15924. This is the service type for the @uref{https://redis.io/, Redis}
  15925. key/value store, whose value is a @code{redis-configuration} object.
  15926. @end defvr
  15927. @deftp {Data Type} redis-configuration
  15928. Data type representing the configuration of redis.
  15929. @table @asis
  15930. @item @code{redis} (default: @code{redis})
  15931. The Redis package to use.
  15932. @item @code{bind} (default: @code{"127.0.0.1"})
  15933. Network interface on which to listen.
  15934. @item @code{port} (default: @code{6379})
  15935. Port on which to accept connections on, a value of 0 will disable
  15936. listening on a TCP socket.
  15937. @item @code{working-directory} (default: @code{"/var/lib/redis"})
  15938. Directory in which to store the database and related files.
  15939. @end table
  15940. @end deftp
  15941. @node Mail Services
  15942. @subsection Mail Services
  15943. @cindex mail
  15944. @cindex email
  15945. The @code{(gnu services mail)} module provides Guix service definitions
  15946. for email services: IMAP, POP3, and LMTP servers, as well as mail
  15947. transport agents (MTAs). Lots of acronyms! These services are detailed
  15948. in the subsections below.
  15949. @subsubheading Dovecot Service
  15950. @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
  15951. Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
  15952. @end deffn
  15953. By default, Dovecot does not need much configuration; the default
  15954. configuration object created by @code{(dovecot-configuration)} will
  15955. suffice if your mail is delivered to @code{~/Maildir}. A self-signed
  15956. certificate will be generated for TLS-protected connections, though
  15957. Dovecot will also listen on cleartext ports by default. There are a
  15958. number of options, though, which mail administrators might need to change,
  15959. and as is the case with other services, Guix allows the system
  15960. administrator to specify these parameters via a uniform Scheme interface.
  15961. For example, to specify that mail is located at @code{maildir~/.mail},
  15962. one would instantiate the Dovecot service like this:
  15963. @lisp
  15964. (dovecot-service #:config
  15965. (dovecot-configuration
  15966. (mail-location "maildir:~/.mail")))
  15967. @end lisp
  15968. The available configuration parameters follow. Each parameter
  15969. definition is preceded by its type; for example, @samp{string-list foo}
  15970. indicates that the @code{foo} parameter should be specified as a list of
  15971. strings. There is also a way to specify the configuration as a string,
  15972. if you have an old @code{dovecot.conf} file that you want to port over
  15973. from some other system; see the end for more details.
  15974. @c The following documentation was initially generated by
  15975. @c (generate-documentation) in (gnu services mail). Manually maintained
  15976. @c documentation is better, so we shouldn't hesitate to edit below as
  15977. @c needed. However if the change you want to make to this documentation
  15978. @c can be done in an automated way, it's probably easier to change
  15979. @c (generate-documentation) than to make it below and have to deal with
  15980. @c the churn as dovecot updates.
  15981. Available @code{dovecot-configuration} fields are:
  15982. @deftypevr {@code{dovecot-configuration} parameter} package dovecot
  15983. The dovecot package.
  15984. @end deftypevr
  15985. @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
  15986. A list of IPs or hosts where to listen for connections. @samp{*}
  15987. listens on all IPv4 interfaces, @samp{::} listens on all IPv6
  15988. interfaces. If you want to specify non-default ports or anything more
  15989. complex, customize the address and port fields of the
  15990. @samp{inet-listener} of the specific services you are interested in.
  15991. @end deftypevr
  15992. @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
  15993. List of protocols we want to serve. Available protocols include
  15994. @samp{imap}, @samp{pop3}, and @samp{lmtp}.
  15995. Available @code{protocol-configuration} fields are:
  15996. @deftypevr {@code{protocol-configuration} parameter} string name
  15997. The name of the protocol.
  15998. @end deftypevr
  15999. @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
  16000. UNIX socket path to the master authentication server to find users.
  16001. This is used by imap (for shared users) and lda.
  16002. It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
  16003. @end deftypevr
  16004. @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
  16005. Space separated list of plugins to load.
  16006. @end deftypevr
  16007. @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
  16008. Maximum number of IMAP connections allowed for a user from each IP
  16009. address. NOTE: The username is compared case-sensitively.
  16010. Defaults to @samp{10}.
  16011. @end deftypevr
  16012. @end deftypevr
  16013. @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
  16014. List of services to enable. Available services include @samp{imap},
  16015. @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
  16016. @samp{lmtp}.
  16017. Available @code{service-configuration} fields are:
  16018. @deftypevr {@code{service-configuration} parameter} string kind
  16019. The service kind. Valid values include @code{director},
  16020. @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
  16021. @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
  16022. @code{tcpwrap}, @code{quota-warning}, or anything else.
  16023. @end deftypevr
  16024. @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
  16025. Listeners for the service. A listener is either a
  16026. @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
  16027. an @code{inet-listener-configuration}.
  16028. Defaults to @samp{()}.
  16029. Available @code{unix-listener-configuration} fields are:
  16030. @deftypevr {@code{unix-listener-configuration} parameter} string path
  16031. Path to the file, relative to @code{base-dir} field. This is also used as
  16032. the section name.
  16033. @end deftypevr
  16034. @deftypevr {@code{unix-listener-configuration} parameter} string mode
  16035. The access mode for the socket.
  16036. Defaults to @samp{"0600"}.
  16037. @end deftypevr
  16038. @deftypevr {@code{unix-listener-configuration} parameter} string user
  16039. The user to own the socket.
  16040. Defaults to @samp{""}.
  16041. @end deftypevr
  16042. @deftypevr {@code{unix-listener-configuration} parameter} string group
  16043. The group to own the socket.
  16044. Defaults to @samp{""}.
  16045. @end deftypevr
  16046. Available @code{fifo-listener-configuration} fields are:
  16047. @deftypevr {@code{fifo-listener-configuration} parameter} string path
  16048. Path to the file, relative to @code{base-dir} field. This is also used as
  16049. the section name.
  16050. @end deftypevr
  16051. @deftypevr {@code{fifo-listener-configuration} parameter} string mode
  16052. The access mode for the socket.
  16053. Defaults to @samp{"0600"}.
  16054. @end deftypevr
  16055. @deftypevr {@code{fifo-listener-configuration} parameter} string user
  16056. The user to own the socket.
  16057. Defaults to @samp{""}.
  16058. @end deftypevr
  16059. @deftypevr {@code{fifo-listener-configuration} parameter} string group
  16060. The group to own the socket.
  16061. Defaults to @samp{""}.
  16062. @end deftypevr
  16063. Available @code{inet-listener-configuration} fields are:
  16064. @deftypevr {@code{inet-listener-configuration} parameter} string protocol
  16065. The protocol to listen for.
  16066. @end deftypevr
  16067. @deftypevr {@code{inet-listener-configuration} parameter} string address
  16068. The address on which to listen, or empty for all addresses.
  16069. Defaults to @samp{""}.
  16070. @end deftypevr
  16071. @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
  16072. The port on which to listen.
  16073. @end deftypevr
  16074. @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
  16075. Whether to use SSL for this service; @samp{yes}, @samp{no}, or
  16076. @samp{required}.
  16077. Defaults to @samp{#t}.
  16078. @end deftypevr
  16079. @end deftypevr
  16080. @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
  16081. Maximum number of simultaneous client connections per process. Once
  16082. this number of connections is received, the next incoming connection
  16083. will prompt Dovecot to spawn another process. If set to 0,
  16084. @code{default-client-limit} is used instead.
  16085. Defaults to @samp{0}.
  16086. @end deftypevr
  16087. @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
  16088. Number of connections to handle before starting a new process.
  16089. Typically the only useful values are 0 (unlimited) or 1. 1 is more
  16090. secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
  16091. Defaults to @samp{1}.
  16092. @end deftypevr
  16093. @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
  16094. Maximum number of processes that can exist for this service. If set to
  16095. 0, @code{default-process-limit} is used instead.
  16096. Defaults to @samp{0}.
  16097. @end deftypevr
  16098. @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
  16099. Number of processes to always keep waiting for more connections.
  16100. Defaults to @samp{0}.
  16101. @end deftypevr
  16102. @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
  16103. If you set @samp{service-count 0}, you probably need to grow
  16104. this.
  16105. Defaults to @samp{256000000}.
  16106. @end deftypevr
  16107. @end deftypevr
  16108. @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
  16109. Dict configuration, as created by the @code{dict-configuration}
  16110. constructor.
  16111. Available @code{dict-configuration} fields are:
  16112. @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
  16113. A list of key-value pairs that this dict should hold.
  16114. Defaults to @samp{()}.
  16115. @end deftypevr
  16116. @end deftypevr
  16117. @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
  16118. A list of passdb configurations, each one created by the
  16119. @code{passdb-configuration} constructor.
  16120. Available @code{passdb-configuration} fields are:
  16121. @deftypevr {@code{passdb-configuration} parameter} string driver
  16122. The driver that the passdb should use. Valid values include
  16123. @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
  16124. @samp{static}.
  16125. Defaults to @samp{"pam"}.
  16126. @end deftypevr
  16127. @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
  16128. Space separated list of arguments to the passdb driver.
  16129. Defaults to @samp{""}.
  16130. @end deftypevr
  16131. @end deftypevr
  16132. @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
  16133. List of userdb configurations, each one created by the
  16134. @code{userdb-configuration} constructor.
  16135. Available @code{userdb-configuration} fields are:
  16136. @deftypevr {@code{userdb-configuration} parameter} string driver
  16137. The driver that the userdb should use. Valid values include
  16138. @samp{passwd} and @samp{static}.
  16139. Defaults to @samp{"passwd"}.
  16140. @end deftypevr
  16141. @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
  16142. Space separated list of arguments to the userdb driver.
  16143. Defaults to @samp{""}.
  16144. @end deftypevr
  16145. @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
  16146. Override fields from passwd.
  16147. Defaults to @samp{()}.
  16148. @end deftypevr
  16149. @end deftypevr
  16150. @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
  16151. Plug-in configuration, created by the @code{plugin-configuration}
  16152. constructor.
  16153. @end deftypevr
  16154. @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
  16155. List of namespaces. Each item in the list is created by the
  16156. @code{namespace-configuration} constructor.
  16157. Available @code{namespace-configuration} fields are:
  16158. @deftypevr {@code{namespace-configuration} parameter} string name
  16159. Name for this namespace.
  16160. @end deftypevr
  16161. @deftypevr {@code{namespace-configuration} parameter} string type
  16162. Namespace type: @samp{private}, @samp{shared} or @samp{public}.
  16163. Defaults to @samp{"private"}.
  16164. @end deftypevr
  16165. @deftypevr {@code{namespace-configuration} parameter} string separator
  16166. Hierarchy separator to use. You should use the same separator for
  16167. all namespaces or some clients get confused. @samp{/} is usually a good
  16168. one. The default however depends on the underlying mail storage
  16169. format.
  16170. Defaults to @samp{""}.
  16171. @end deftypevr
  16172. @deftypevr {@code{namespace-configuration} parameter} string prefix
  16173. Prefix required to access this namespace. This needs to be
  16174. different for all namespaces. For example @samp{Public/}.
  16175. Defaults to @samp{""}.
  16176. @end deftypevr
  16177. @deftypevr {@code{namespace-configuration} parameter} string location
  16178. Physical location of the mailbox. This is in the same format as
  16179. mail_location, which is also the default for it.
  16180. Defaults to @samp{""}.
  16181. @end deftypevr
  16182. @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
  16183. There can be only one INBOX, and this setting defines which
  16184. namespace has it.
  16185. Defaults to @samp{#f}.
  16186. @end deftypevr
  16187. @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
  16188. If namespace is hidden, it's not advertised to clients via NAMESPACE
  16189. extension. You'll most likely also want to set @samp{list? #f}. This is mostly
  16190. useful when converting from another server with different namespaces
  16191. which you want to deprecate but still keep working. For example you can
  16192. create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
  16193. and @samp{mail/}.
  16194. Defaults to @samp{#f}.
  16195. @end deftypevr
  16196. @deftypevr {@code{namespace-configuration} parameter} boolean list?
  16197. Show the mailboxes under this namespace with the LIST command. This
  16198. makes the namespace visible for clients that do not support the NAMESPACE
  16199. extension. The special @code{children} value lists child mailboxes, but
  16200. hides the namespace prefix.
  16201. Defaults to @samp{#t}.
  16202. @end deftypevr
  16203. @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
  16204. Namespace handles its own subscriptions. If set to @code{#f}, the
  16205. parent namespace handles them. The empty prefix should always have this
  16206. as @code{#t}).
  16207. Defaults to @samp{#t}.
  16208. @end deftypevr
  16209. @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
  16210. List of predefined mailboxes in this namespace.
  16211. Defaults to @samp{()}.
  16212. Available @code{mailbox-configuration} fields are:
  16213. @deftypevr {@code{mailbox-configuration} parameter} string name
  16214. Name for this mailbox.
  16215. @end deftypevr
  16216. @deftypevr {@code{mailbox-configuration} parameter} string auto
  16217. @samp{create} will automatically create this mailbox.
  16218. @samp{subscribe} will both create and subscribe to the mailbox.
  16219. Defaults to @samp{"no"}.
  16220. @end deftypevr
  16221. @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
  16222. List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
  16223. Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
  16224. @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
  16225. Defaults to @samp{()}.
  16226. @end deftypevr
  16227. @end deftypevr
  16228. @end deftypevr
  16229. @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
  16230. Base directory where to store runtime data.
  16231. Defaults to @samp{"/var/run/dovecot/"}.
  16232. @end deftypevr
  16233. @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
  16234. Greeting message for clients.
  16235. Defaults to @samp{"Dovecot ready."}.
  16236. @end deftypevr
  16237. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
  16238. List of trusted network ranges. Connections from these IPs are
  16239. allowed to override their IP addresses and ports (for logging and for
  16240. authentication checks). @samp{disable-plaintext-auth} is also ignored
  16241. for these networks. Typically you would specify your IMAP proxy servers
  16242. here.
  16243. Defaults to @samp{()}.
  16244. @end deftypevr
  16245. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
  16246. List of login access check sockets (e.g.@: tcpwrap).
  16247. Defaults to @samp{()}.
  16248. @end deftypevr
  16249. @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
  16250. Show more verbose process titles (in ps). Currently shows user name
  16251. and IP address. Useful for seeing who is actually using the IMAP
  16252. processes (e.g.@: shared mailboxes or if the same uid is used for multiple
  16253. accounts).
  16254. Defaults to @samp{#f}.
  16255. @end deftypevr
  16256. @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
  16257. Should all processes be killed when Dovecot master process shuts down.
  16258. Setting this to @code{#f} means that Dovecot can be upgraded without
  16259. forcing existing client connections to close (although that could also
  16260. be a problem if the upgrade is e.g.@: due to a security fix).
  16261. Defaults to @samp{#t}.
  16262. @end deftypevr
  16263. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
  16264. If non-zero, run mail commands via this many connections to doveadm
  16265. server, instead of running them directly in the same process.
  16266. Defaults to @samp{0}.
  16267. @end deftypevr
  16268. @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
  16269. UNIX socket or host:port used for connecting to doveadm server.
  16270. Defaults to @samp{"doveadm-server"}.
  16271. @end deftypevr
  16272. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
  16273. List of environment variables that are preserved on Dovecot startup
  16274. and passed down to all of its child processes. You can also give
  16275. key=value pairs to always set specific settings.
  16276. @end deftypevr
  16277. @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
  16278. Disable LOGIN command and all other plaintext authentications unless
  16279. SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
  16280. matches the local IP (i.e.@: you're connecting from the same computer),
  16281. the connection is considered secure and plaintext authentication is
  16282. allowed. See also ssl=required setting.
  16283. Defaults to @samp{#t}.
  16284. @end deftypevr
  16285. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
  16286. Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
  16287. Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
  16288. for caching to be used.
  16289. Defaults to @samp{0}.
  16290. @end deftypevr
  16291. @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
  16292. Time to live for cached data. After TTL expires the cached record
  16293. is no longer used, *except* if the main database lookup returns internal
  16294. failure. We also try to handle password changes automatically: If
  16295. user's previous authentication was successful, but this one wasn't, the
  16296. cache isn't used. For now this works only with plaintext
  16297. authentication.
  16298. Defaults to @samp{"1 hour"}.
  16299. @end deftypevr
  16300. @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
  16301. TTL for negative hits (user not found, password mismatch).
  16302. 0 disables caching them completely.
  16303. Defaults to @samp{"1 hour"}.
  16304. @end deftypevr
  16305. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
  16306. List of realms for SASL authentication mechanisms that need them.
  16307. You can leave it empty if you don't want to support multiple realms.
  16308. Many clients simply use the first one listed here, so keep the default
  16309. realm first.
  16310. Defaults to @samp{()}.
  16311. @end deftypevr
  16312. @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
  16313. Default realm/domain to use if none was specified. This is used for
  16314. both SASL realms and appending @@domain to username in plaintext
  16315. logins.
  16316. Defaults to @samp{""}.
  16317. @end deftypevr
  16318. @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
  16319. List of allowed characters in username. If the user-given username
  16320. contains a character not listed in here, the login automatically fails.
  16321. This is just an extra check to make sure user can't exploit any
  16322. potential quote escaping vulnerabilities with SQL/LDAP databases. If
  16323. you want to allow all characters, set this value to empty.
  16324. Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
  16325. @end deftypevr
  16326. @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
  16327. Username character translations before it's looked up from
  16328. databases. The value contains series of from -> to characters. For
  16329. example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
  16330. translated to @samp{@@}.
  16331. Defaults to @samp{""}.
  16332. @end deftypevr
  16333. @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
  16334. Username formatting before it's looked up from databases. You can
  16335. use the standard variables here, e.g.@: %Lu would lowercase the username,
  16336. %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
  16337. change the @samp{@@} into @samp{-AT-}. This translation is done after
  16338. @samp{auth-username-translation} changes.
  16339. Defaults to @samp{"%Lu"}.
  16340. @end deftypevr
  16341. @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
  16342. If you want to allow master users to log in by specifying the master
  16343. username within the normal username string (i.e.@: not using SASL
  16344. mechanism's support for it), you can specify the separator character
  16345. here. The format is then <username><separator><master username>.
  16346. UW-IMAP uses @samp{*} as the separator, so that could be a good
  16347. choice.
  16348. Defaults to @samp{""}.
  16349. @end deftypevr
  16350. @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
  16351. Username to use for users logging in with ANONYMOUS SASL
  16352. mechanism.
  16353. Defaults to @samp{"anonymous"}.
  16354. @end deftypevr
  16355. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
  16356. Maximum number of dovecot-auth worker processes. They're used to
  16357. execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
  16358. They're automatically created and destroyed as needed.
  16359. Defaults to @samp{30}.
  16360. @end deftypevr
  16361. @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
  16362. Host name to use in GSSAPI principal names. The default is to use
  16363. the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
  16364. allow all keytab entries.
  16365. Defaults to @samp{""}.
  16366. @end deftypevr
  16367. @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
  16368. Kerberos keytab to use for the GSSAPI mechanism. Will use the
  16369. system default (usually @file{/etc/krb5.keytab}) if not specified. You may
  16370. need to change the auth service to run as root to be able to read this
  16371. file.
  16372. Defaults to @samp{""}.
  16373. @end deftypevr
  16374. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
  16375. Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
  16376. and @samp{ntlm-auth} helper.
  16377. <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
  16378. Defaults to @samp{#f}.
  16379. @end deftypevr
  16380. @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
  16381. Path for Samba's @samp{ntlm-auth} helper binary.
  16382. Defaults to @samp{"/usr/bin/ntlm_auth"}.
  16383. @end deftypevr
  16384. @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
  16385. Time to delay before replying to failed authentications.
  16386. Defaults to @samp{"2 secs"}.
  16387. @end deftypevr
  16388. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
  16389. Require a valid SSL client certificate or the authentication
  16390. fails.
  16391. Defaults to @samp{#f}.
  16392. @end deftypevr
  16393. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
  16394. Take the username from client's SSL certificate, using
  16395. @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
  16396. CommonName.
  16397. Defaults to @samp{#f}.
  16398. @end deftypevr
  16399. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
  16400. List of wanted authentication mechanisms. Supported mechanisms are:
  16401. @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
  16402. @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
  16403. @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
  16404. @samp{disable-plaintext-auth} setting.
  16405. @end deftypevr
  16406. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
  16407. List of IPs or hostnames to all director servers, including ourself.
  16408. Ports can be specified as ip:port. The default port is the same as what
  16409. director service's @samp{inet-listener} is using.
  16410. Defaults to @samp{()}.
  16411. @end deftypevr
  16412. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
  16413. List of IPs or hostnames to all backend mail servers. Ranges are
  16414. allowed too, like 10.0.0.10-10.0.0.30.
  16415. Defaults to @samp{()}.
  16416. @end deftypevr
  16417. @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
  16418. How long to redirect users to a specific server after it no longer
  16419. has any connections.
  16420. Defaults to @samp{"15 min"}.
  16421. @end deftypevr
  16422. @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
  16423. How the username is translated before being hashed. Useful values
  16424. include %Ln if user can log in with or without @@domain, %Ld if mailboxes
  16425. are shared within domain.
  16426. Defaults to @samp{"%Lu"}.
  16427. @end deftypevr
  16428. @deftypevr {@code{dovecot-configuration} parameter} string log-path
  16429. Log file to use for error messages. @samp{syslog} logs to syslog,
  16430. @samp{/dev/stderr} logs to stderr.
  16431. Defaults to @samp{"syslog"}.
  16432. @end deftypevr
  16433. @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
  16434. Log file to use for informational messages. Defaults to
  16435. @samp{log-path}.
  16436. Defaults to @samp{""}.
  16437. @end deftypevr
  16438. @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
  16439. Log file to use for debug messages. Defaults to
  16440. @samp{info-log-path}.
  16441. Defaults to @samp{""}.
  16442. @end deftypevr
  16443. @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
  16444. Syslog facility to use if you're logging to syslog. Usually if you
  16445. don't want to use @samp{mail}, you'll use local0..local7. Also other
  16446. standard facilities are supported.
  16447. Defaults to @samp{"mail"}.
  16448. @end deftypevr
  16449. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
  16450. Log unsuccessful authentication attempts and the reasons why they
  16451. failed.
  16452. Defaults to @samp{#f}.
  16453. @end deftypevr
  16454. @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
  16455. In case of password mismatches, log the attempted password. Valid
  16456. values are no, plain and sha1. sha1 can be useful for detecting brute
  16457. force password attempts vs. user simply trying the same password over
  16458. and over again. You can also truncate the value to n chars by appending
  16459. ":n" (e.g.@: sha1:6).
  16460. Defaults to @samp{"no"}.
  16461. @end deftypevr
  16462. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
  16463. Even more verbose logging for debugging purposes. Shows for example
  16464. SQL queries.
  16465. Defaults to @samp{#f}.
  16466. @end deftypevr
  16467. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
  16468. In case of password mismatches, log the passwords and used scheme so
  16469. the problem can be debugged. Enabling this also enables
  16470. @samp{auth-debug}.
  16471. Defaults to @samp{#f}.
  16472. @end deftypevr
  16473. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
  16474. Enable mail process debugging. This can help you figure out why
  16475. Dovecot isn't finding your mails.
  16476. Defaults to @samp{#f}.
  16477. @end deftypevr
  16478. @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
  16479. Show protocol level SSL errors.
  16480. Defaults to @samp{#f}.
  16481. @end deftypevr
  16482. @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
  16483. Prefix for each line written to log file. % codes are in
  16484. strftime(3) format.
  16485. Defaults to @samp{"\"%b %d %H:%M:%S \""}.
  16486. @end deftypevr
  16487. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
  16488. List of elements we want to log. The elements which have a
  16489. non-empty variable value are joined together to form a comma-separated
  16490. string.
  16491. @end deftypevr
  16492. @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
  16493. Login log format. %s contains @samp{login-log-format-elements}
  16494. string, %$ contains the data we want to log.
  16495. Defaults to @samp{"%$: %s"}.
  16496. @end deftypevr
  16497. @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
  16498. Log prefix for mail processes. See doc/wiki/Variables.txt for list
  16499. of possible variables you can use.
  16500. Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
  16501. @end deftypevr
  16502. @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
  16503. Format to use for logging mail deliveries. You can use variables:
  16504. @table @code
  16505. @item %$
  16506. Delivery status message (e.g.@: @samp{saved to INBOX})
  16507. @item %m
  16508. Message-ID
  16509. @item %s
  16510. Subject
  16511. @item %f
  16512. From address
  16513. @item %p
  16514. Physical size
  16515. @item %w
  16516. Virtual size.
  16517. @end table
  16518. Defaults to @samp{"msgid=%m: %$"}.
  16519. @end deftypevr
  16520. @deftypevr {@code{dovecot-configuration} parameter} string mail-location
  16521. Location for users' mailboxes. The default is empty, which means
  16522. that Dovecot tries to find the mailboxes automatically. This won't work
  16523. if the user doesn't yet have any mail, so you should explicitly tell
  16524. Dovecot the full location.
  16525. If you're using mbox, giving a path to the INBOX
  16526. file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
  16527. where the other mailboxes are kept. This is called the @emph{root mail
  16528. directory}, and it must be the first path given in the
  16529. @samp{mail-location} setting.
  16530. There are a few special variables you can use, e.g.:
  16531. @table @samp
  16532. @item %u
  16533. username
  16534. @item %n
  16535. user part in user@@domain, same as %u if there's no domain
  16536. @item %d
  16537. domain part in user@@domain, empty if there's no domain
  16538. @item %h
  16539. home director
  16540. @end table
  16541. See doc/wiki/Variables.txt for full list. Some examples:
  16542. @table @samp
  16543. @item maildir:~/Maildir
  16544. @item mbox:~/mail:INBOX=/var/mail/%u
  16545. @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
  16546. @end table
  16547. Defaults to @samp{""}.
  16548. @end deftypevr
  16549. @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
  16550. System user and group used to access mails. If you use multiple,
  16551. userdb can override these by returning uid or gid fields. You can use
  16552. either numbers or names. <doc/wiki/UserIds.txt>.
  16553. Defaults to @samp{""}.
  16554. @end deftypevr
  16555. @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
  16556. Defaults to @samp{""}.
  16557. @end deftypevr
  16558. @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
  16559. Group to enable temporarily for privileged operations. Currently
  16560. this is used only with INBOX when either its initial creation or
  16561. dotlocking fails. Typically this is set to @samp{"mail"} to give access to
  16562. @file{/var/mail}.
  16563. Defaults to @samp{""}.
  16564. @end deftypevr
  16565. @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
  16566. Grant access to these supplementary groups for mail processes.
  16567. Typically these are used to set up access to shared mailboxes. Note
  16568. that it may be dangerous to set these if users can create symlinks
  16569. (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
  16570. could allow a user to delete others' mailboxes, or @code{ln -s
  16571. /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
  16572. @samp{""}.
  16573. @end deftypevr
  16574. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
  16575. Allow full file system access to clients. There's no access checks
  16576. other than what the operating system does for the active UID/GID@. It
  16577. works with both maildir and mboxes, allowing you to prefix mailboxes
  16578. names with e.g.@: @file{/path/} or @file{~user/}.
  16579. Defaults to @samp{#f}.
  16580. @end deftypevr
  16581. @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
  16582. Don't use @code{mmap()} at all. This is required if you store indexes to
  16583. shared file systems (NFS or clustered file system).
  16584. Defaults to @samp{#f}.
  16585. @end deftypevr
  16586. @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
  16587. Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
  16588. supports @samp{O_EXCL} since version 3, so this should be safe to use
  16589. nowadays by default.
  16590. Defaults to @samp{#t}.
  16591. @end deftypevr
  16592. @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
  16593. When to use fsync() or fdatasync() calls:
  16594. @table @code
  16595. @item optimized
  16596. Whenever necessary to avoid losing important data
  16597. @item always
  16598. Useful with e.g.@: NFS when @code{write()}s are delayed
  16599. @item never
  16600. Never use it (best performance, but crashes can lose data).
  16601. @end table
  16602. Defaults to @samp{"optimized"}.
  16603. @end deftypevr
  16604. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
  16605. Mail storage exists in NFS@. Set this to yes to make Dovecot flush
  16606. NFS caches whenever needed. If you're using only a single mail server
  16607. this isn't needed.
  16608. Defaults to @samp{#f}.
  16609. @end deftypevr
  16610. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
  16611. Mail index files also exist in NFS@. Setting this to yes requires
  16612. @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
  16613. Defaults to @samp{#f}.
  16614. @end deftypevr
  16615. @deftypevr {@code{dovecot-configuration} parameter} string lock-method
  16616. Locking method for index files. Alternatives are fcntl, flock and
  16617. dotlock. Dotlocking uses some tricks which may create more disk I/O
  16618. than other locking methods. NFS users: flock doesn't work, remember to
  16619. change @samp{mmap-disable}.
  16620. Defaults to @samp{"fcntl"}.
  16621. @end deftypevr
  16622. @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
  16623. Directory in which LDA/LMTP temporarily stores incoming mails >128
  16624. kB.
  16625. Defaults to @samp{"/tmp"}.
  16626. @end deftypevr
  16627. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
  16628. Valid UID range for users. This is mostly to make sure that users can't
  16629. log in as daemons or other system users. Note that denying root logins is
  16630. hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
  16631. is set to 0.
  16632. Defaults to @samp{500}.
  16633. @end deftypevr
  16634. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
  16635. Defaults to @samp{0}.
  16636. @end deftypevr
  16637. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
  16638. Valid GID range for users. Users having non-valid GID as primary group ID
  16639. aren't allowed to log in. If user belongs to supplementary groups with
  16640. non-valid GIDs, those groups are not set.
  16641. Defaults to @samp{1}.
  16642. @end deftypevr
  16643. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
  16644. Defaults to @samp{0}.
  16645. @end deftypevr
  16646. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
  16647. Maximum allowed length for mail keyword name. It's only forced when
  16648. trying to create new keywords.
  16649. Defaults to @samp{50}.
  16650. @end deftypevr
  16651. @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
  16652. List of directories under which chrooting is allowed for mail
  16653. processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
  16654. too). This setting doesn't affect @samp{login-chroot}
  16655. @samp{mail-chroot} or auth chroot settings. If this setting is empty,
  16656. @samp{/./} in home dirs are ignored. WARNING: Never add directories here
  16657. which local users can modify, that may lead to root exploit. Usually
  16658. this should be done only if you don't allow shell access for users.
  16659. <doc/wiki/Chrooting.txt>.
  16660. Defaults to @samp{()}.
  16661. @end deftypevr
  16662. @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
  16663. Default chroot directory for mail processes. This can be overridden
  16664. for specific users in user database by giving @samp{/./} in user's home
  16665. directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
  16666. there is no real need to do chrooting, Dovecot doesn't allow users to
  16667. access files outside their mail directory anyway. If your home
  16668. directories are prefixed with the chroot directory, append @samp{/.} to
  16669. @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
  16670. Defaults to @samp{""}.
  16671. @end deftypevr
  16672. @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
  16673. UNIX socket path to master authentication server to find users.
  16674. This is used by imap (for shared users) and lda.
  16675. Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
  16676. @end deftypevr
  16677. @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
  16678. Directory where to look up mail plugins.
  16679. Defaults to @samp{"/usr/lib/dovecot"}.
  16680. @end deftypevr
  16681. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
  16682. List of plugins to load for all services. Plugins specific to IMAP,
  16683. LDA, etc.@: are added to this list in their own .conf files.
  16684. Defaults to @samp{()}.
  16685. @end deftypevr
  16686. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
  16687. The minimum number of mails in a mailbox before updates are done to
  16688. cache file. This allows optimizing Dovecot's behavior to do less disk
  16689. writes at the cost of more disk reads.
  16690. Defaults to @samp{0}.
  16691. @end deftypevr
  16692. @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
  16693. When IDLE command is running, mailbox is checked once in a while to
  16694. see if there are any new mails or other changes. This setting defines
  16695. the minimum time to wait between those checks. Dovecot can also use
  16696. dnotify, inotify and kqueue to find out immediately when changes
  16697. occur.
  16698. Defaults to @samp{"30 secs"}.
  16699. @end deftypevr
  16700. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
  16701. Save mails with CR+LF instead of plain LF@. This makes sending those
  16702. mails take less CPU, especially with sendfile() syscall with Linux and
  16703. FreeBSD@. But it also creates a bit more disk I/O which may just make it
  16704. slower. Also note that if other software reads the mboxes/maildirs,
  16705. they may handle the extra CRs wrong and cause problems.
  16706. Defaults to @samp{#f}.
  16707. @end deftypevr
  16708. @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
  16709. By default LIST command returns all entries in maildir beginning
  16710. with a dot. Enabling this option makes Dovecot return only entries
  16711. which are directories. This is done by stat()ing each entry, so it
  16712. causes more disk I/O.
  16713. (For systems setting struct @samp{dirent->d_type} this check is free
  16714. and it's done always regardless of this setting).
  16715. Defaults to @samp{#f}.
  16716. @end deftypevr
  16717. @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
  16718. When copying a message, do it with hard links whenever possible.
  16719. This makes the performance much better, and it's unlikely to have any
  16720. side effects.
  16721. Defaults to @samp{#t}.
  16722. @end deftypevr
  16723. @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
  16724. Assume Dovecot is the only MUA accessing Maildir: Scan cur/
  16725. directory only when its mtime changes unexpectedly or when we can't find
  16726. the mail otherwise.
  16727. Defaults to @samp{#f}.
  16728. @end deftypevr
  16729. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
  16730. Which locking methods to use for locking mbox. There are four
  16731. available:
  16732. @table @code
  16733. @item dotlock
  16734. Create <mailbox>.lock file. This is the oldest and most NFS-safe
  16735. solution. If you want to use /var/mail/ like directory, the users will
  16736. need write access to that directory.
  16737. @item dotlock-try
  16738. Same as dotlock, but if it fails because of permissions or because there
  16739. isn't enough disk space, just skip it.
  16740. @item fcntl
  16741. Use this if possible. Works with NFS too if lockd is used.
  16742. @item flock
  16743. May not exist in all systems. Doesn't work with NFS.
  16744. @item lockf
  16745. May not exist in all systems. Doesn't work with NFS.
  16746. @end table
  16747. You can use multiple locking methods; if you do the order they're declared
  16748. in is important to avoid deadlocks if other MTAs/MUAs are using multiple
  16749. locking methods as well. Some operating systems don't allow using some of
  16750. them simultaneously.
  16751. @end deftypevr
  16752. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
  16753. @end deftypevr
  16754. @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
  16755. Maximum time to wait for lock (all of them) before aborting.
  16756. Defaults to @samp{"5 mins"}.
  16757. @end deftypevr
  16758. @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
  16759. If dotlock exists but the mailbox isn't modified in any way,
  16760. override the lock file after this much time.
  16761. Defaults to @samp{"2 mins"}.
  16762. @end deftypevr
  16763. @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
  16764. When mbox changes unexpectedly we have to fully read it to find out
  16765. what changed. If the mbox is large this can take a long time. Since
  16766. the change is usually just a newly appended mail, it'd be faster to
  16767. simply read the new mails. If this setting is enabled, Dovecot does
  16768. this but still safely fallbacks to re-reading the whole mbox file
  16769. whenever something in mbox isn't how it's expected to be. The only real
  16770. downside to this setting is that if some other MUA changes message
  16771. flags, Dovecot doesn't notice it immediately. Note that a full sync is
  16772. done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
  16773. Defaults to @samp{#t}.
  16774. @end deftypevr
  16775. @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
  16776. Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
  16777. EXAMINE, EXPUNGE or CHECK commands. If this is set,
  16778. @samp{mbox-dirty-syncs} is ignored.
  16779. Defaults to @samp{#f}.
  16780. @end deftypevr
  16781. @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
  16782. Delay writing mbox headers until doing a full write sync (EXPUNGE
  16783. and CHECK commands and when closing the mailbox). This is especially
  16784. useful for POP3 where clients often delete all mails. The downside is
  16785. that our changes aren't immediately visible to other MUAs.
  16786. Defaults to @samp{#t}.
  16787. @end deftypevr
  16788. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
  16789. If mbox size is smaller than this (e.g.@: 100k), don't write index
  16790. files. If an index file already exists it's still read, just not
  16791. updated.
  16792. Defaults to @samp{0}.
  16793. @end deftypevr
  16794. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
  16795. Maximum dbox file size until it's rotated.
  16796. Defaults to @samp{10000000}.
  16797. @end deftypevr
  16798. @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
  16799. Maximum dbox file age until it's rotated. Typically in days. Day
  16800. begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
  16801. disabled.
  16802. Defaults to @samp{"1d"}.
  16803. @end deftypevr
  16804. @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
  16805. When creating new mdbox files, immediately preallocate their size to
  16806. @samp{mdbox-rotate-size}. This setting currently works only in Linux
  16807. with some file systems (ext4, xfs).
  16808. Defaults to @samp{#f}.
  16809. @end deftypevr
  16810. @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
  16811. sdbox and mdbox support saving mail attachments to external files,
  16812. which also allows single instance storage for them. Other backends
  16813. don't support this for now.
  16814. WARNING: This feature hasn't been tested much yet. Use at your own risk.
  16815. Directory root where to store mail attachments. Disabled, if empty.
  16816. Defaults to @samp{""}.
  16817. @end deftypevr
  16818. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
  16819. Attachments smaller than this aren't saved externally. It's also
  16820. possible to write a plugin to disable saving specific attachments
  16821. externally.
  16822. Defaults to @samp{128000}.
  16823. @end deftypevr
  16824. @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
  16825. File system backend to use for saving attachments:
  16826. @table @code
  16827. @item posix
  16828. No SiS done by Dovecot (but this might help FS's own deduplication)
  16829. @item sis posix
  16830. SiS with immediate byte-by-byte comparison during saving
  16831. @item sis-queue posix
  16832. SiS with delayed comparison and deduplication.
  16833. @end table
  16834. Defaults to @samp{"sis posix"}.
  16835. @end deftypevr
  16836. @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
  16837. Hash format to use in attachment filenames. You can add any text and
  16838. variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
  16839. @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
  16840. truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
  16841. Defaults to @samp{"%@{sha1@}"}.
  16842. @end deftypevr
  16843. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
  16844. Defaults to @samp{100}.
  16845. @end deftypevr
  16846. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
  16847. Defaults to @samp{1000}.
  16848. @end deftypevr
  16849. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
  16850. Default VSZ (virtual memory size) limit for service processes.
  16851. This is mainly intended to catch and kill processes that leak memory
  16852. before they eat up everything.
  16853. Defaults to @samp{256000000}.
  16854. @end deftypevr
  16855. @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
  16856. Login user is internally used by login processes. This is the most
  16857. untrusted user in Dovecot system. It shouldn't have access to anything
  16858. at all.
  16859. Defaults to @samp{"dovenull"}.
  16860. @end deftypevr
  16861. @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
  16862. Internal user is used by unprivileged processes. It should be
  16863. separate from login user, so that login processes can't disturb other
  16864. processes.
  16865. Defaults to @samp{"dovecot"}.
  16866. @end deftypevr
  16867. @deftypevr {@code{dovecot-configuration} parameter} string ssl?
  16868. SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
  16869. Defaults to @samp{"required"}.
  16870. @end deftypevr
  16871. @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
  16872. PEM encoded X.509 SSL/TLS certificate (public key).
  16873. Defaults to @samp{"</etc/dovecot/default.pem"}.
  16874. @end deftypevr
  16875. @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
  16876. PEM encoded SSL/TLS private key. The key is opened before
  16877. dropping root privileges, so keep the key file unreadable by anyone but
  16878. root.
  16879. Defaults to @samp{"</etc/dovecot/private/default.pem"}.
  16880. @end deftypevr
  16881. @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
  16882. If key file is password protected, give the password here.
  16883. Alternatively give it when starting dovecot with -p parameter. Since
  16884. this file is often world-readable, you may want to place this setting
  16885. instead to a different.
  16886. Defaults to @samp{""}.
  16887. @end deftypevr
  16888. @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
  16889. PEM encoded trusted certificate authority. Set this only if you
  16890. intend to use @samp{ssl-verify-client-cert? #t}. The file should
  16891. contain the CA certificate(s) followed by the matching
  16892. CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
  16893. Defaults to @samp{""}.
  16894. @end deftypevr
  16895. @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
  16896. Require that CRL check succeeds for client certificates.
  16897. Defaults to @samp{#t}.
  16898. @end deftypevr
  16899. @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
  16900. Request client to send a certificate. If you also want to require
  16901. it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
  16902. Defaults to @samp{#f}.
  16903. @end deftypevr
  16904. @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
  16905. Which field from certificate to use for username. commonName and
  16906. x500UniqueIdentifier are the usual choices. You'll also need to set
  16907. @samp{auth-ssl-username-from-cert? #t}.
  16908. Defaults to @samp{"commonName"}.
  16909. @end deftypevr
  16910. @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
  16911. Minimum SSL protocol version to accept.
  16912. Defaults to @samp{"TLSv1"}.
  16913. @end deftypevr
  16914. @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
  16915. SSL ciphers to use.
  16916. Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
  16917. @end deftypevr
  16918. @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
  16919. SSL crypto device to use, for valid values run "openssl engine".
  16920. Defaults to @samp{""}.
  16921. @end deftypevr
  16922. @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
  16923. Address to use when sending rejection mails.
  16924. %d expands to recipient domain.
  16925. Defaults to @samp{"postmaster@@%d"}.
  16926. @end deftypevr
  16927. @deftypevr {@code{dovecot-configuration} parameter} string hostname
  16928. Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
  16929. and in LMTP replies. Default is the system's real hostname@@domain.
  16930. Defaults to @samp{""}.
  16931. @end deftypevr
  16932. @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
  16933. If user is over quota, return with temporary failure instead of
  16934. bouncing the mail.
  16935. Defaults to @samp{#f}.
  16936. @end deftypevr
  16937. @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
  16938. Binary to use for sending mails.
  16939. Defaults to @samp{"/usr/sbin/sendmail"}.
  16940. @end deftypevr
  16941. @deftypevr {@code{dovecot-configuration} parameter} string submission-host
  16942. If non-empty, send mails via this SMTP host[:port] instead of
  16943. sendmail.
  16944. Defaults to @samp{""}.
  16945. @end deftypevr
  16946. @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
  16947. Subject: header to use for rejection mails. You can use the same
  16948. variables as for @samp{rejection-reason} below.
  16949. Defaults to @samp{"Rejected: %s"}.
  16950. @end deftypevr
  16951. @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
  16952. Human readable error message for rejection mails. You can use
  16953. variables:
  16954. @table @code
  16955. @item %n
  16956. CRLF
  16957. @item %r
  16958. reason
  16959. @item %s
  16960. original subject
  16961. @item %t
  16962. recipient
  16963. @end table
  16964. Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
  16965. @end deftypevr
  16966. @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
  16967. Delimiter character between local-part and detail in email
  16968. address.
  16969. Defaults to @samp{"+"}.
  16970. @end deftypevr
  16971. @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
  16972. Header where the original recipient address (SMTP's RCPT TO:
  16973. address) is taken from if not available elsewhere. With dovecot-lda -a
  16974. parameter overrides this. A commonly used header for this is
  16975. X-Original-To.
  16976. Defaults to @samp{""}.
  16977. @end deftypevr
  16978. @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
  16979. Should saving a mail to a nonexistent mailbox automatically create
  16980. it?.
  16981. Defaults to @samp{#f}.
  16982. @end deftypevr
  16983. @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
  16984. Should automatically created mailboxes be also automatically
  16985. subscribed?.
  16986. Defaults to @samp{#f}.
  16987. @end deftypevr
  16988. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
  16989. Maximum IMAP command line length. Some clients generate very long
  16990. command lines with huge mailboxes, so you may need to raise this if you
  16991. get "Too long argument" or "IMAP command line too large" errors
  16992. often.
  16993. Defaults to @samp{64000}.
  16994. @end deftypevr
  16995. @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
  16996. IMAP logout format string:
  16997. @table @code
  16998. @item %i
  16999. total number of bytes read from client
  17000. @item %o
  17001. total number of bytes sent to client.
  17002. @end table
  17003. See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
  17004. 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@}"}.
  17005. @end deftypevr
  17006. @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
  17007. Override the IMAP CAPABILITY response. If the value begins with '+',
  17008. add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
  17009. Defaults to @samp{""}.
  17010. @end deftypevr
  17011. @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
  17012. How long to wait between "OK Still here" notifications when client
  17013. is IDLEing.
  17014. Defaults to @samp{"2 mins"}.
  17015. @end deftypevr
  17016. @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
  17017. ID field names and values to send to clients. Using * as the value
  17018. makes Dovecot use the default value. The following fields have default
  17019. values currently: name, version, os, os-version, support-url,
  17020. support-email.
  17021. Defaults to @samp{""}.
  17022. @end deftypevr
  17023. @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
  17024. ID fields sent by client to log. * means everything.
  17025. Defaults to @samp{""}.
  17026. @end deftypevr
  17027. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
  17028. Workarounds for various client bugs:
  17029. @table @code
  17030. @item delay-newmail
  17031. Send EXISTS/RECENT new mail notifications only when replying to NOOP and
  17032. CHECK commands. Some clients ignore them otherwise, for example OSX
  17033. Mail (<v2.1). Outlook Express breaks more badly though, without this it
  17034. may show user "Message no longer in server" errors. Note that OE6
  17035. still breaks even with this workaround if synchronization is set to
  17036. "Headers Only".
  17037. @item tb-extra-mailbox-sep
  17038. Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
  17039. adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
  17040. ignore the extra @samp{/} instead of treating it as invalid mailbox name.
  17041. @item tb-lsub-flags
  17042. Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
  17043. This makes Thunderbird realize they aren't selectable and show them
  17044. greyed out, instead of only later giving "not selectable" popup error.
  17045. @end table
  17046. Defaults to @samp{()}.
  17047. @end deftypevr
  17048. @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
  17049. Host allowed in URLAUTH URLs sent by client. "*" allows all.
  17050. Defaults to @samp{""}.
  17051. @end deftypevr
  17052. Whew! Lots of configuration options. The nice thing about it though is
  17053. that Guix has a complete interface to Dovecot's configuration
  17054. language. This allows not only a nice way to declare configurations,
  17055. but also offers reflective capabilities as well: users can write code to
  17056. inspect and transform configurations from within Scheme.
  17057. However, it could be that you just want to get a @code{dovecot.conf} up
  17058. and running. In that case, you can pass an
  17059. @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
  17060. @code{dovecot-service}. As its name indicates, an opaque configuration
  17061. does not have easy reflective capabilities.
  17062. Available @code{opaque-dovecot-configuration} fields are:
  17063. @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
  17064. The dovecot package.
  17065. @end deftypevr
  17066. @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
  17067. The contents of the @code{dovecot.conf}, as a string.
  17068. @end deftypevr
  17069. For example, if your @code{dovecot.conf} is just the empty string, you
  17070. could instantiate a dovecot service like this:
  17071. @lisp
  17072. (dovecot-service #:config
  17073. (opaque-dovecot-configuration
  17074. (string "")))
  17075. @end lisp
  17076. @subsubheading OpenSMTPD Service
  17077. @deffn {Scheme Variable} opensmtpd-service-type
  17078. This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
  17079. service, whose value should be an @code{opensmtpd-configuration} object
  17080. as in this example:
  17081. @lisp
  17082. (service opensmtpd-service-type
  17083. (opensmtpd-configuration
  17084. (config-file (local-file "./my-smtpd.conf"))))
  17085. @end lisp
  17086. @end deffn
  17087. @deftp {Data Type} opensmtpd-configuration
  17088. Data type representing the configuration of opensmtpd.
  17089. @table @asis
  17090. @item @code{package} (default: @var{opensmtpd})
  17091. Package object of the OpenSMTPD SMTP server.
  17092. @item @code{config-file} (default: @code{%default-opensmtpd-file})
  17093. File-like object of the OpenSMTPD configuration file to use. By default
  17094. it listens on the loopback network interface, and allows for mail from
  17095. users and daemons on the local machine, as well as permitting email to
  17096. remote servers. Run @command{man smtpd.conf} for more information.
  17097. @end table
  17098. @end deftp
  17099. @subsubheading Exim Service
  17100. @cindex mail transfer agent (MTA)
  17101. @cindex MTA (mail transfer agent)
  17102. @cindex SMTP
  17103. @deffn {Scheme Variable} exim-service-type
  17104. This is the type of the @uref{https://exim.org, Exim} mail transfer
  17105. agent (MTA), whose value should be an @code{exim-configuration} object
  17106. as in this example:
  17107. @lisp
  17108. (service exim-service-type
  17109. (exim-configuration
  17110. (config-file (local-file "./my-exim.conf"))))
  17111. @end lisp
  17112. @end deffn
  17113. In order to use an @code{exim-service-type} service you must also have a
  17114. @code{mail-aliases-service-type} service present in your
  17115. @code{operating-system} (even if it has no aliases).
  17116. @deftp {Data Type} exim-configuration
  17117. Data type representing the configuration of exim.
  17118. @table @asis
  17119. @item @code{package} (default: @var{exim})
  17120. Package object of the Exim server.
  17121. @item @code{config-file} (default: @code{#f})
  17122. File-like object of the Exim configuration file to use. If its value is
  17123. @code{#f} then use the default configuration file from the package
  17124. provided in @code{package}. The resulting configuration file is loaded
  17125. after setting the @code{exim_user} and @code{exim_group} configuration
  17126. variables.
  17127. @end table
  17128. @end deftp
  17129. @subsubheading Getmail service
  17130. @cindex IMAP
  17131. @cindex POP
  17132. @deffn {Scheme Variable} getmail-service-type
  17133. This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
  17134. mail retriever, whose value should be an @code{getmail-configuration}.
  17135. @end deffn
  17136. Available @code{getmail-configuration} fields are:
  17137. @deftypevr {@code{getmail-configuration} parameter} symbol name
  17138. A symbol to identify the getmail service.
  17139. Defaults to @samp{"unset"}.
  17140. @end deftypevr
  17141. @deftypevr {@code{getmail-configuration} parameter} package package
  17142. The getmail package to use.
  17143. @end deftypevr
  17144. @deftypevr {@code{getmail-configuration} parameter} string user
  17145. The user to run getmail as.
  17146. Defaults to @samp{"getmail"}.
  17147. @end deftypevr
  17148. @deftypevr {@code{getmail-configuration} parameter} string group
  17149. The group to run getmail as.
  17150. Defaults to @samp{"getmail"}.
  17151. @end deftypevr
  17152. @deftypevr {@code{getmail-configuration} parameter} string directory
  17153. The getmail directory to use.
  17154. Defaults to @samp{"/var/lib/getmail/default"}.
  17155. @end deftypevr
  17156. @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
  17157. The getmail configuration file to use.
  17158. Available @code{getmail-configuration-file} fields are:
  17159. @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
  17160. What mail account to retrieve mail from, and how to access that account.
  17161. Available @code{getmail-retriever-configuration} fields are:
  17162. @deftypevr {@code{getmail-retriever-configuration} parameter} string type
  17163. The type of mail retriever to use. Valid values include @samp{passwd}
  17164. and @samp{static}.
  17165. Defaults to @samp{"SimpleIMAPSSLRetriever"}.
  17166. @end deftypevr
  17167. @deftypevr {@code{getmail-retriever-configuration} parameter} string server
  17168. Username to login to the mail server with.
  17169. Defaults to @samp{unset}.
  17170. @end deftypevr
  17171. @deftypevr {@code{getmail-retriever-configuration} parameter} string username
  17172. Username to login to the mail server with.
  17173. Defaults to @samp{unset}.
  17174. @end deftypevr
  17175. @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
  17176. Port number to connect to.
  17177. Defaults to @samp{#f}.
  17178. @end deftypevr
  17179. @deftypevr {@code{getmail-retriever-configuration} parameter} string password
  17180. Override fields from passwd.
  17181. Defaults to @samp{""}.
  17182. @end deftypevr
  17183. @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
  17184. Override fields from passwd.
  17185. Defaults to @samp{()}.
  17186. @end deftypevr
  17187. @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
  17188. PEM-formatted key file to use for the TLS negotiation.
  17189. Defaults to @samp{""}.
  17190. @end deftypevr
  17191. @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
  17192. PEM-formatted certificate file to use for the TLS negotiation.
  17193. Defaults to @samp{""}.
  17194. @end deftypevr
  17195. @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
  17196. CA certificates to use.
  17197. Defaults to @samp{""}.
  17198. @end deftypevr
  17199. @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
  17200. Extra retriever parameters.
  17201. Defaults to @samp{()}.
  17202. @end deftypevr
  17203. @end deftypevr
  17204. @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
  17205. What to do with retrieved messages.
  17206. Available @code{getmail-destination-configuration} fields are:
  17207. @deftypevr {@code{getmail-destination-configuration} parameter} string type
  17208. The type of mail destination. Valid values include @samp{Maildir},
  17209. @samp{Mboxrd} and @samp{MDA_external}.
  17210. Defaults to @samp{unset}.
  17211. @end deftypevr
  17212. @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
  17213. The path option for the mail destination. The behaviour depends on the
  17214. chosen type.
  17215. Defaults to @samp{""}.
  17216. @end deftypevr
  17217. @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
  17218. Extra destination parameters
  17219. Defaults to @samp{()}.
  17220. @end deftypevr
  17221. @end deftypevr
  17222. @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
  17223. Configure getmail.
  17224. Available @code{getmail-options-configuration} fields are:
  17225. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
  17226. If set to @samp{0}, getmail will only print warnings and errors. A
  17227. value of @samp{1} means that messages will be printed about retrieving
  17228. and deleting messages. If set to @samp{2}, getmail will print messages
  17229. about each of it's actions.
  17230. Defaults to @samp{1}.
  17231. @end deftypevr
  17232. @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
  17233. If true, getmail will retrieve all available messages. Otherwise it
  17234. will only retrieve messages it hasn't seen previously.
  17235. Defaults to @samp{#t}.
  17236. @end deftypevr
  17237. @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
  17238. If set to true, messages will be deleted from the server after
  17239. retrieving and successfully delivering them. Otherwise, messages will
  17240. be left on the server.
  17241. Defaults to @samp{#f}.
  17242. @end deftypevr
  17243. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
  17244. Getmail will delete messages this number of days after seeing them, if
  17245. they have been delivered. This means messages will be left on the
  17246. server this number of days after delivering them. A value of @samp{0}
  17247. disabled this feature.
  17248. Defaults to @samp{0}.
  17249. @end deftypevr
  17250. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
  17251. Delete messages larger than this of bytes after retrieving them, even if
  17252. the delete and delete-after options are disabled. A value of @samp{0}
  17253. disables this feature.
  17254. Defaults to @samp{0}.
  17255. @end deftypevr
  17256. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
  17257. Retrieve messages totalling up to this number of bytes before closing
  17258. the session with the server. A value of @samp{0} disables this feature.
  17259. Defaults to @samp{0}.
  17260. @end deftypevr
  17261. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
  17262. Don't retrieve messages larger than this number of bytes. A value of
  17263. @samp{0} disables this feature.
  17264. Defaults to @samp{0}.
  17265. @end deftypevr
  17266. @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
  17267. If true, getmail will add a Delivered-To header to messages.
  17268. Defaults to @samp{#t}.
  17269. @end deftypevr
  17270. @deftypevr {@code{getmail-options-configuration} parameter} boolean received
  17271. If set, getmail adds a Received header to the messages.
  17272. Defaults to @samp{#t}.
  17273. @end deftypevr
  17274. @deftypevr {@code{getmail-options-configuration} parameter} string message-log
  17275. Getmail will record a log of its actions to the named file. A value of
  17276. @samp{""} disables this feature.
  17277. Defaults to @samp{""}.
  17278. @end deftypevr
  17279. @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
  17280. If true, getmail will record a log of its actions using the system
  17281. logger.
  17282. Defaults to @samp{#f}.
  17283. @end deftypevr
  17284. @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
  17285. If true, getmail will log information about messages not retrieved and
  17286. the reason for not retrieving them, as well as starting and ending
  17287. information lines.
  17288. Defaults to @samp{#f}.
  17289. @end deftypevr
  17290. @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
  17291. Extra options to include.
  17292. Defaults to @samp{()}.
  17293. @end deftypevr
  17294. @end deftypevr
  17295. @end deftypevr
  17296. @deftypevr {@code{getmail-configuration} parameter} list idle
  17297. A list of mailboxes that getmail should wait on the server for new mail
  17298. notifications. This depends on the server supporting the IDLE
  17299. extension.
  17300. Defaults to @samp{()}.
  17301. @end deftypevr
  17302. @deftypevr {@code{getmail-configuration} parameter} list environment-variables
  17303. Environment variables to set for getmail.
  17304. Defaults to @samp{()}.
  17305. @end deftypevr
  17306. @subsubheading Mail Aliases Service
  17307. @cindex email aliases
  17308. @cindex aliases, for email addresses
  17309. @deffn {Scheme Variable} mail-aliases-service-type
  17310. This is the type of the service which provides @code{/etc/aliases},
  17311. specifying how to deliver mail to users on this system.
  17312. @lisp
  17313. (service mail-aliases-service-type
  17314. '(("postmaster" "bob")
  17315. ("bob" "bob@@example.com" "bob@@example2.com")))
  17316. @end lisp
  17317. @end deffn
  17318. The configuration for a @code{mail-aliases-service-type} service is an
  17319. association list denoting how to deliver mail that comes to this
  17320. system. Each entry is of the form @code{(alias addresses ...)}, with
  17321. @code{alias} specifying the local alias and @code{addresses} specifying
  17322. where to deliver this user's mail.
  17323. The aliases aren't required to exist as users on the local system. In
  17324. the above example, there doesn't need to be a @code{postmaster} entry in
  17325. the @code{operating-system}'s @code{user-accounts} in order to deliver
  17326. the @code{postmaster} mail to @code{bob} (which subsequently would
  17327. deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
  17328. @subsubheading GNU Mailutils IMAP4 Daemon
  17329. @cindex GNU Mailutils IMAP4 Daemon
  17330. @deffn {Scheme Variable} imap4d-service-type
  17331. This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
  17332. mailutils, GNU Mailutils Manual}), whose value should be an
  17333. @code{imap4d-configuration} object as in this example:
  17334. @lisp
  17335. (service imap4d-service-type
  17336. (imap4d-configuration
  17337. (config-file (local-file "imap4d.conf"))))
  17338. @end lisp
  17339. @end deffn
  17340. @deftp {Data Type} imap4d-configuration
  17341. Data type representing the configuration of @command{imap4d}.
  17342. @table @asis
  17343. @item @code{package} (default: @code{mailutils})
  17344. The package that provides @command{imap4d}.
  17345. @item @code{config-file} (default: @code{%default-imap4d-config-file})
  17346. File-like object of the configuration file to use, by default it will listen
  17347. on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
  17348. Mailutils Manual}, for details.
  17349. @end table
  17350. @end deftp
  17351. @subsubheading Radicale Service
  17352. @cindex CalDAV
  17353. @cindex CardDAV
  17354. @deffn {Scheme Variable} radicale-service-type
  17355. This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
  17356. server whose value should be a @code{radicale-configuration}.
  17357. @end deffn
  17358. @deftp {Data Type} radicale-configuration
  17359. Data type representing the configuration of @command{radicale}.
  17360. @table @asis
  17361. @item @code{package} (default: @code{radicale})
  17362. The package that provides @command{radicale}.
  17363. @item @code{config-file} (default: @code{%default-radicale-config-file})
  17364. File-like object of the configuration file to use, by default it will listen
  17365. on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
  17366. @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
  17367. @end table
  17368. @end deftp
  17369. @node Messaging Services
  17370. @subsection Messaging Services
  17371. @cindex messaging
  17372. @cindex jabber
  17373. @cindex XMPP
  17374. The @code{(gnu services messaging)} module provides Guix service
  17375. definitions for messaging services. Currently it provides the following
  17376. services:
  17377. @subsubheading Prosody Service
  17378. @deffn {Scheme Variable} prosody-service-type
  17379. This is the type for the @uref{https://prosody.im, Prosody XMPP
  17380. communication server}. Its value must be a @code{prosody-configuration}
  17381. record as in this example:
  17382. @lisp
  17383. (service prosody-service-type
  17384. (prosody-configuration
  17385. (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
  17386. (int-components
  17387. (list
  17388. (int-component-configuration
  17389. (hostname "conference.example.net")
  17390. (plugin "muc")
  17391. (mod-muc (mod-muc-configuration)))))
  17392. (virtualhosts
  17393. (list
  17394. (virtualhost-configuration
  17395. (domain "example.net"))))))
  17396. @end lisp
  17397. See below for details about @code{prosody-configuration}.
  17398. @end deffn
  17399. By default, Prosody does not need much configuration. Only one
  17400. @code{virtualhosts} field is needed: it specifies the domain you wish
  17401. Prosody to serve.
  17402. You can perform various sanity checks on the generated configuration
  17403. with the @code{prosodyctl check} command.
  17404. Prosodyctl will also help you to import certificates from the
  17405. @code{letsencrypt} directory so that the @code{prosody} user can access
  17406. them. See @url{https://prosody.im/doc/letsencrypt}.
  17407. @example
  17408. prosodyctl --root cert import /etc/letsencrypt/live
  17409. @end example
  17410. The available configuration parameters follow. Each parameter
  17411. definition is preceded by its type; for example, @samp{string-list foo}
  17412. indicates that the @code{foo} parameter should be specified as a list of
  17413. strings. Types starting with @code{maybe-} denote parameters that won't
  17414. show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
  17415. There is also a way to specify the configuration as a string, if you
  17416. have an old @code{prosody.cfg.lua} file that you want to port over from
  17417. some other system; see the end for more details.
  17418. The @code{file-object} type designates either a file-like object
  17419. (@pxref{G-Expressions, file-like objects}) or a file name.
  17420. @c The following documentation was initially generated by
  17421. @c (generate-documentation) in (gnu services messaging). Manually maintained
  17422. @c documentation is better, so we shouldn't hesitate to edit below as
  17423. @c needed. However if the change you want to make to this documentation
  17424. @c can be done in an automated way, it's probably easier to change
  17425. @c (generate-documentation) than to make it below and have to deal with
  17426. @c the churn as Prosody updates.
  17427. Available @code{prosody-configuration} fields are:
  17428. @deftypevr {@code{prosody-configuration} parameter} package prosody
  17429. The Prosody package.
  17430. @end deftypevr
  17431. @deftypevr {@code{prosody-configuration} parameter} file-name data-path
  17432. Location of the Prosody data storage directory. See
  17433. @url{https://prosody.im/doc/configure}.
  17434. Defaults to @samp{"/var/lib/prosody"}.
  17435. @end deftypevr
  17436. @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
  17437. Additional plugin directories. They are searched in all the specified
  17438. paths in order. See @url{https://prosody.im/doc/plugins_directory}.
  17439. Defaults to @samp{()}.
  17440. @end deftypevr
  17441. @deftypevr {@code{prosody-configuration} parameter} file-name certificates
  17442. Every virtual host and component needs a certificate so that clients and
  17443. servers can securely verify its identity. Prosody will automatically load
  17444. certificates/keys from the directory specified here.
  17445. Defaults to @samp{"/etc/prosody/certs"}.
  17446. @end deftypevr
  17447. @deftypevr {@code{prosody-configuration} parameter} string-list admins
  17448. This is a list of accounts that are admins for the server. Note that you
  17449. must create the accounts separately. See @url{https://prosody.im/doc/admins} and
  17450. @url{https://prosody.im/doc/creating_accounts}.
  17451. Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
  17452. Defaults to @samp{()}.
  17453. @end deftypevr
  17454. @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
  17455. Enable use of libevent for better performance under high load. See
  17456. @url{https://prosody.im/doc/libevent}.
  17457. Defaults to @samp{#f}.
  17458. @end deftypevr
  17459. @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
  17460. This is the list of modules Prosody will load on startup. It looks for
  17461. @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
  17462. Documentation on modules can be found at:
  17463. @url{https://prosody.im/doc/modules}.
  17464. Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
  17465. @end deftypevr
  17466. @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
  17467. @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
  17468. should you want to disable them then add them to this list.
  17469. Defaults to @samp{()}.
  17470. @end deftypevr
  17471. @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
  17472. Path to a text file where the shared groups are defined. If this path is
  17473. empty then @samp{mod_groups} does nothing. See
  17474. @url{https://prosody.im/doc/modules/mod_groups}.
  17475. Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
  17476. @end deftypevr
  17477. @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
  17478. Disable account creation by default, for security. See
  17479. @url{https://prosody.im/doc/creating_accounts}.
  17480. Defaults to @samp{#f}.
  17481. @end deftypevr
  17482. @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
  17483. These are the SSL/TLS-related settings. Most of them are disabled so to
  17484. use Prosody's defaults. If you do not completely understand these options, do
  17485. not add them to your config, it is easy to lower the security of your server
  17486. using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
  17487. Available @code{ssl-configuration} fields are:
  17488. @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
  17489. This determines what handshake to use.
  17490. @end deftypevr
  17491. @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
  17492. Path to your private key file.
  17493. @end deftypevr
  17494. @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
  17495. Path to your certificate file.
  17496. @end deftypevr
  17497. @deftypevr {@code{ssl-configuration} parameter} file-object capath
  17498. Path to directory containing root certificates that you wish Prosody to
  17499. trust when verifying the certificates of remote servers.
  17500. Defaults to @samp{"/etc/ssl/certs"}.
  17501. @end deftypevr
  17502. @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
  17503. Path to a file containing root certificates that you wish Prosody to trust.
  17504. Similar to @code{capath} but with all certificates concatenated together.
  17505. @end deftypevr
  17506. @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
  17507. A list of verification options (these mostly map to OpenSSL's
  17508. @code{set_verify()} flags).
  17509. @end deftypevr
  17510. @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
  17511. A list of general options relating to SSL/TLS@. These map to OpenSSL's
  17512. @code{set_options()}. For a full list of options available in LuaSec, see the
  17513. LuaSec source.
  17514. @end deftypevr
  17515. @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
  17516. How long a chain of certificate authorities to check when looking for a
  17517. trusted root certificate.
  17518. @end deftypevr
  17519. @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
  17520. An OpenSSL cipher string. This selects what ciphers Prosody will offer to
  17521. clients, and in what order.
  17522. @end deftypevr
  17523. @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
  17524. A path to a file containing parameters for Diffie-Hellman key exchange. You
  17525. can create such a file with:
  17526. @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
  17527. @end deftypevr
  17528. @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
  17529. Curve for Elliptic curve Diffie-Hellman. Prosody's default is
  17530. @samp{"secp384r1"}.
  17531. @end deftypevr
  17532. @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
  17533. A list of ``extra'' verification options.
  17534. @end deftypevr
  17535. @deftypevr {@code{ssl-configuration} parameter} maybe-string password
  17536. Password for encrypted private keys.
  17537. @end deftypevr
  17538. @end deftypevr
  17539. @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
  17540. Whether to force all client-to-server connections to be encrypted or not.
  17541. See @url{https://prosody.im/doc/modules/mod_tls}.
  17542. Defaults to @samp{#f}.
  17543. @end deftypevr
  17544. @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
  17545. Set of mechanisms that will never be offered. See
  17546. @url{https://prosody.im/doc/modules/mod_saslauth}.
  17547. Defaults to @samp{("DIGEST-MD5")}.
  17548. @end deftypevr
  17549. @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
  17550. Whether to force all server-to-server connections to be encrypted or not.
  17551. See @url{https://prosody.im/doc/modules/mod_tls}.
  17552. Defaults to @samp{#f}.
  17553. @end deftypevr
  17554. @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
  17555. Whether to require encryption and certificate authentication. This
  17556. provides ideal security, but requires servers you communicate with to support
  17557. encryption AND present valid, trusted certificates. See
  17558. @url{https://prosody.im/doc/s2s#security}.
  17559. Defaults to @samp{#f}.
  17560. @end deftypevr
  17561. @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
  17562. Many servers don't support encryption or have invalid or self-signed
  17563. certificates. You can list domains here that will not be required to
  17564. authenticate using certificates. They will be authenticated using DNS@. See
  17565. @url{https://prosody.im/doc/s2s#security}.
  17566. Defaults to @samp{()}.
  17567. @end deftypevr
  17568. @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
  17569. Even if you leave @code{s2s-secure-auth?} disabled, you can still require
  17570. valid certificates for some domains by specifying a list here. See
  17571. @url{https://prosody.im/doc/s2s#security}.
  17572. Defaults to @samp{()}.
  17573. @end deftypevr
  17574. @deftypevr {@code{prosody-configuration} parameter} string authentication
  17575. Select the authentication backend to use. The default provider stores
  17576. passwords in plaintext and uses Prosody's configured data storage to store the
  17577. authentication data. If you do not trust your server please see
  17578. @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
  17579. about using the hashed backend. See also
  17580. @url{https://prosody.im/doc/authentication}
  17581. Defaults to @samp{"internal_plain"}.
  17582. @end deftypevr
  17583. @deftypevr {@code{prosody-configuration} parameter} maybe-string log
  17584. Set logging options. Advanced logging configuration is not yet supported
  17585. by the Prosody service. See @url{https://prosody.im/doc/logging}.
  17586. Defaults to @samp{"*syslog"}.
  17587. @end deftypevr
  17588. @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
  17589. File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
  17590. Defaults to @samp{"/var/run/prosody/prosody.pid"}.
  17591. @end deftypevr
  17592. @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
  17593. Maximum allowed size of the HTTP body (in bytes).
  17594. @end deftypevr
  17595. @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
  17596. Some modules expose their own URL in various ways. This URL is built
  17597. from the protocol, host and port used. If Prosody sits behind a proxy, the
  17598. public URL will be @code{http-external-url} instead. See
  17599. @url{https://prosody.im/doc/http#external_url}.
  17600. @end deftypevr
  17601. @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
  17602. A host in Prosody is a domain on which user accounts can be created. For
  17603. example if you want your users to have addresses like
  17604. @samp{"john.smith@@example.com"} then you need to add a host
  17605. @samp{"example.com"}. All options in this list will apply only to this host.
  17606. Note: the name @emph{virtual} host is used in configuration to avoid confusion with
  17607. the actual physical host that Prosody is installed on. A single Prosody
  17608. instance can serve many domains, each one defined as a VirtualHost entry in
  17609. Prosody's configuration. Conversely a server that hosts a single domain would
  17610. have just one VirtualHost entry.
  17611. See @url{https://prosody.im/doc/configure#virtual_host_settings}.
  17612. Available @code{virtualhost-configuration} fields are:
  17613. 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:
  17614. @deftypevr {@code{virtualhost-configuration} parameter} string domain
  17615. Domain you wish Prosody to serve.
  17616. @end deftypevr
  17617. @end deftypevr
  17618. @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
  17619. Components are extra services on a server which are available to clients,
  17620. usually on a subdomain of the main server (such as
  17621. @samp{"mycomponent.example.com"}). Example components might be chatroom
  17622. servers, user directories, or gateways to other protocols.
  17623. Internal components are implemented with Prosody-specific plugins. To add an
  17624. internal component, you simply fill the hostname field, and the plugin you wish
  17625. to use for the component.
  17626. See @url{https://prosody.im/doc/components}.
  17627. Defaults to @samp{()}.
  17628. Available @code{int-component-configuration} fields are:
  17629. 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:
  17630. @deftypevr {@code{int-component-configuration} parameter} string hostname
  17631. Hostname of the component.
  17632. @end deftypevr
  17633. @deftypevr {@code{int-component-configuration} parameter} string plugin
  17634. Plugin you wish to use for the component.
  17635. @end deftypevr
  17636. @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
  17637. Multi-user chat (MUC) is Prosody's module for allowing you to create
  17638. hosted chatrooms/conferences for XMPP users.
  17639. General information on setting up and using multi-user chatrooms can be found
  17640. in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
  17641. which you should read if you are new to XMPP chatrooms.
  17642. See also @url{https://prosody.im/doc/modules/mod_muc}.
  17643. Available @code{mod-muc-configuration} fields are:
  17644. @deftypevr {@code{mod-muc-configuration} parameter} string name
  17645. The name to return in service discovery responses.
  17646. Defaults to @samp{"Prosody Chatrooms"}.
  17647. @end deftypevr
  17648. @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
  17649. If @samp{#t}, this will only allow admins to create new chatrooms.
  17650. Otherwise anyone can create a room. The value @samp{"local"} restricts room
  17651. creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
  17652. can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
  17653. restricts to service administrators only.
  17654. Defaults to @samp{#f}.
  17655. @end deftypevr
  17656. @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
  17657. Maximum number of history messages that will be sent to the member that has
  17658. just joined the room.
  17659. Defaults to @samp{20}.
  17660. @end deftypevr
  17661. @end deftypevr
  17662. @end deftypevr
  17663. @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
  17664. External components use XEP-0114, which most standalone components
  17665. support. To add an external component, you simply fill the hostname field. See
  17666. @url{https://prosody.im/doc/components}.
  17667. Defaults to @samp{()}.
  17668. Available @code{ext-component-configuration} fields are:
  17669. 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:
  17670. @deftypevr {@code{ext-component-configuration} parameter} string component-secret
  17671. Password which the component will use to log in.
  17672. @end deftypevr
  17673. @deftypevr {@code{ext-component-configuration} parameter} string hostname
  17674. Hostname of the component.
  17675. @end deftypevr
  17676. @end deftypevr
  17677. @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
  17678. Port(s) Prosody listens on for component connections.
  17679. Defaults to @samp{(5347)}.
  17680. @end deftypevr
  17681. @deftypevr {@code{prosody-configuration} parameter} string component-interface
  17682. Interface Prosody listens on for component connections.
  17683. Defaults to @samp{"127.0.0.1"}.
  17684. @end deftypevr
  17685. @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
  17686. Raw content that will be added to the configuration file.
  17687. @end deftypevr
  17688. It could be that you just want to get a @code{prosody.cfg.lua}
  17689. up and running. In that case, you can pass an
  17690. @code{opaque-prosody-configuration} record as the value of
  17691. @code{prosody-service-type}. As its name indicates, an opaque configuration
  17692. does not have easy reflective capabilities.
  17693. Available @code{opaque-prosody-configuration} fields are:
  17694. @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
  17695. The prosody package.
  17696. @end deftypevr
  17697. @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
  17698. The contents of the @code{prosody.cfg.lua} to use.
  17699. @end deftypevr
  17700. For example, if your @code{prosody.cfg.lua} is just the empty
  17701. string, you could instantiate a prosody service like this:
  17702. @lisp
  17703. (service prosody-service-type
  17704. (opaque-prosody-configuration
  17705. (prosody.cfg.lua "")))
  17706. @end lisp
  17707. @c end of Prosody auto-generated documentation
  17708. @subsubheading BitlBee Service
  17709. @cindex IRC (Internet Relay Chat)
  17710. @cindex IRC gateway
  17711. @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
  17712. interface to a variety of messaging protocols such as XMPP.
  17713. @defvr {Scheme Variable} bitlbee-service-type
  17714. This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
  17715. gateway daemon. Its value is a @code{bitlbee-configuration} (see
  17716. below).
  17717. To have BitlBee listen on port 6667 on localhost, add this line to your
  17718. services:
  17719. @lisp
  17720. (service bitlbee-service-type)
  17721. @end lisp
  17722. @end defvr
  17723. @deftp {Data Type} bitlbee-configuration
  17724. This is the configuration for BitlBee, with the following fields:
  17725. @table @asis
  17726. @item @code{interface} (default: @code{"127.0.0.1"})
  17727. @itemx @code{port} (default: @code{6667})
  17728. Listen on the network interface corresponding to the IP address
  17729. specified in @var{interface}, on @var{port}.
  17730. When @var{interface} is @code{127.0.0.1}, only local clients can
  17731. connect; when it is @code{0.0.0.0}, connections can come from any
  17732. networking interface.
  17733. @item @code{bitlbee} (default: @code{bitlbee})
  17734. The BitlBee package to use.
  17735. @item @code{plugins} (default: @code{'()})
  17736. List of plugin packages to use---e.g., @code{bitlbee-discord}.
  17737. @item @code{extra-settings} (default: @code{""})
  17738. Configuration snippet added as-is to the BitlBee configuration file.
  17739. @end table
  17740. @end deftp
  17741. @subsubheading Quassel Service
  17742. @cindex IRC (Internet Relay Chat)
  17743. @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
  17744. meaning that one or more clients can attach to and detach from the
  17745. central core.
  17746. @defvr {Scheme Variable} quassel-service-type
  17747. This is the service type for the @url{https://quassel-irc.org/,Quassel}
  17748. IRC backend daemon. Its value is a @code{quassel-configuration}
  17749. (see below).
  17750. @end defvr
  17751. @deftp {Data Type} quassel-configuration
  17752. This is the configuration for Quassel, with the following fields:
  17753. @table @asis
  17754. @item @code{quassel} (default: @code{quassel})
  17755. The Quassel package to use.
  17756. @item @code{interface} (default: @code{"::,0.0.0.0"})
  17757. @item @code{port} (default: @code{4242})
  17758. Listen on the network interface(s) corresponding to the IPv4 or IPv6
  17759. interfaces specified in the comma delimited @var{interface}, on
  17760. @var{port}.
  17761. @item @code{loglevel} (default: @code{"Info"})
  17762. The level of logging desired. Accepted values are Debug, Info, Warning
  17763. and Error.
  17764. @end table
  17765. @end deftp
  17766. @node Telephony Services
  17767. @subsection Telephony Services
  17768. @cindex Murmur (VoIP server)
  17769. @cindex VoIP server
  17770. This section describes how to set up and run a Murmur server. Murmur is
  17771. the server of the @uref{https://mumble.info, Mumble} voice-over-IP
  17772. (VoIP) suite.
  17773. @deftp {Data Type} murmur-configuration
  17774. The service type for the Murmur server. An example configuration can
  17775. look like this:
  17776. @lisp
  17777. (service murmur-service-type
  17778. (murmur-configuration
  17779. (welcome-text
  17780. "Welcome to this Mumble server running on Guix!")
  17781. (cert-required? #t) ;disallow text password logins
  17782. (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
  17783. (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
  17784. @end lisp
  17785. After reconfiguring your system, you can manually set the murmur @code{SuperUser}
  17786. password with the command that is printed during the activation phase.
  17787. It is recommended to register a normal Mumble user account
  17788. and grant it admin or moderator rights.
  17789. You can use the @code{mumble} client to
  17790. login as new normal user, register yourself, and log out.
  17791. For the next step login with the name @code{SuperUser} use
  17792. the @code{SuperUser} password that you set previously,
  17793. and grant your newly registered mumble user administrator or moderator
  17794. rights and create some channels.
  17795. Available @code{murmur-configuration} fields are:
  17796. @table @asis
  17797. @item @code{package} (default: @code{mumble})
  17798. Package that contains @code{bin/murmurd}.
  17799. @item @code{user} (default: @code{"murmur"})
  17800. User who will run the Murmur server.
  17801. @item @code{group} (default: @code{"murmur"})
  17802. Group of the user who will run the murmur server.
  17803. @item @code{port} (default: @code{64738})
  17804. Port on which the server will listen.
  17805. @item @code{welcome-text} (default: @code{""})
  17806. Welcome text sent to clients when they connect.
  17807. @item @code{server-password} (default: @code{""})
  17808. Password the clients have to enter in order to connect.
  17809. @item @code{max-users} (default: @code{100})
  17810. Maximum of users that can be connected to the server at once.
  17811. @item @code{max-user-bandwidth} (default: @code{#f})
  17812. Maximum voice traffic a user can send per second.
  17813. @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
  17814. File name of the sqlite database.
  17815. The service's user will become the owner of the directory.
  17816. @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
  17817. File name of the log file.
  17818. The service's user will become the owner of the directory.
  17819. @item @code{autoban-attempts} (default: @code{10})
  17820. Maximum number of logins a user can make in @code{autoban-timeframe}
  17821. without getting auto banned for @code{autoban-time}.
  17822. @item @code{autoban-timeframe} (default: @code{120})
  17823. Timeframe for autoban in seconds.
  17824. @item @code{autoban-time} (default: @code{300})
  17825. Amount of time in seconds for which a client gets banned
  17826. when violating the autoban limits.
  17827. @item @code{opus-threshold} (default: @code{100})
  17828. Percentage of clients that need to support opus
  17829. before switching over to opus audio codec.
  17830. @item @code{channel-nesting-limit} (default: @code{10})
  17831. How deep channels can be nested at maximum.
  17832. @item @code{channelname-regex} (default: @code{#f})
  17833. A string in form of a Qt regular expression that channel names must conform to.
  17834. @item @code{username-regex} (default: @code{#f})
  17835. A string in form of a Qt regular expression that user names must conform to.
  17836. @item @code{text-message-length} (default: @code{5000})
  17837. Maximum size in bytes that a user can send in one text chat message.
  17838. @item @code{image-message-length} (default: @code{(* 128 1024)})
  17839. Maximum size in bytes that a user can send in one image message.
  17840. @item @code{cert-required?} (default: @code{#f})
  17841. If it is set to @code{#t} clients that use weak password authentication
  17842. will not be accepted. Users must have completed the certificate wizard to join.
  17843. @item @code{remember-channel?} (default: @code{#f})
  17844. Should murmur remember the last channel each user was in when they disconnected
  17845. and put them into the remembered channel when they rejoin.
  17846. @item @code{allow-html?} (default: @code{#f})
  17847. Should html be allowed in text messages, user comments, and channel descriptions.
  17848. @item @code{allow-ping?} (default: @code{#f})
  17849. Setting to true exposes the current user count, the maximum user count, and
  17850. the server's maximum bandwidth per client to unauthenticated users. In the
  17851. Mumble client, this information is shown in the Connect dialog.
  17852. Disabling this setting will prevent public listing of the server.
  17853. @item @code{bonjour?} (default: @code{#f})
  17854. Should the server advertise itself in the local network through the bonjour protocol.
  17855. @item @code{send-version?} (default: @code{#f})
  17856. Should the murmur server version be exposed in ping requests.
  17857. @item @code{log-days} (default: @code{31})
  17858. Murmur also stores logs in the database, which are accessible via RPC.
  17859. The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
  17860. or -1 to disable logging to the database.
  17861. @item @code{obfuscate-ips?} (default: @code{#t})
  17862. Should logged ips be obfuscated to protect the privacy of users.
  17863. @item @code{ssl-cert} (default: @code{#f})
  17864. File name of the SSL/TLS certificate used for encrypted connections.
  17865. @lisp
  17866. (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
  17867. @end lisp
  17868. @item @code{ssl-key} (default: @code{#f})
  17869. Filepath to the ssl private key used for encrypted connections.
  17870. @lisp
  17871. (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
  17872. @end lisp
  17873. @item @code{ssl-dh-params} (default: @code{#f})
  17874. File name of a PEM-encoded file with Diffie-Hellman parameters
  17875. for the SSL/TLS encryption. Alternatively you set it to
  17876. @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
  17877. or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
  17878. @item @code{ssl-ciphers} (default: @code{#f})
  17879. The @code{ssl-ciphers} option chooses the cipher suites to make available for use
  17880. in SSL/TLS.
  17881. This option is specified using
  17882. @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
  17883. OpenSSL cipher list notation}.
  17884. It is recommended that you try your cipher string using 'openssl ciphers <string>'
  17885. before setting it here, to get a feel for which cipher suites you will get.
  17886. After setting this option, it is recommend that you inspect your Murmur log
  17887. to ensure that Murmur is using the cipher suites that you expected it to.
  17888. Note: Changing this option may impact the backwards compatibility of your
  17889. Murmur server, and can remove the ability for older Mumble clients to be able
  17890. to connect to it.
  17891. @item @code{public-registration} (default: @code{#f})
  17892. Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
  17893. You can optionally register your server in the public server list that the
  17894. @code{mumble} client shows on startup.
  17895. You cannot register your server if you have set a @code{server-password},
  17896. or set @code{allow-ping} to @code{#f}.
  17897. It might take a few hours until it shows up in the public list.
  17898. @item @code{file} (default: @code{#f})
  17899. Optional alternative override for this configuration.
  17900. @end table
  17901. @end deftp
  17902. @deftp {Data Type} murmur-public-registration-configuration
  17903. Configuration for public registration of a murmur service.
  17904. @table @asis
  17905. @item @code{name}
  17906. This is a display name for your server. Not to be confused with the hostname.
  17907. @item @code{password}
  17908. A password to identify your registration.
  17909. Subsequent updates will need the same password. Don't lose your password.
  17910. @item @code{url}
  17911. This should be a @code{http://} or @code{https://} link to your web
  17912. site.
  17913. @item @code{hostname} (default: @code{#f})
  17914. By default your server will be listed by its IP address.
  17915. If it is set your server will be linked by this host name instead.
  17916. @end table
  17917. @end deftp
  17918. @node File-Sharing Services
  17919. @subsection File-Sharing Services
  17920. The @code{(gnu services file-sharing)} module provides services that
  17921. assist with transferring files over peer-to-peer file-sharing networks.
  17922. @subsubheading Transmission Daemon Service
  17923. @uref{https://transmissionbt.com/, Transmission} is a flexible
  17924. BitTorrent client that offers a variety of graphical and command-line
  17925. interfaces. A @code{transmission-daemon-service-type} service provides
  17926. Transmission's headless variant, @command{transmission-daemon}, as a
  17927. system service, allowing users to share files via BitTorrent even when
  17928. they are not logged in.
  17929. @deffn {Scheme Variable} transmission-daemon-service-type
  17930. The service type for the Transmission Daemon BitTorrent client. Its
  17931. value must be a @code{transmission-daemon-configuration} object as in
  17932. this example:
  17933. @lisp
  17934. (service transmission-daemon-service-type
  17935. (transmission-daemon-configuration
  17936. ;; Restrict access to the RPC ("control") interface
  17937. (rpc-authentication-required? #t)
  17938. (rpc-username "transmission")
  17939. (rpc-password
  17940. (transmission-password-hash
  17941. "transmission" ; desired password
  17942. "uKd1uMs9")) ; arbitrary salt value
  17943. ;; Accept requests from this and other hosts on the
  17944. ;; local network
  17945. (rpc-whitelist-enabled? #t)
  17946. (rpc-whitelist '("::1" "127.0.0.1" "192.168.0.*"))
  17947. ;; Limit bandwidth use during work hours
  17948. (alt-speed-down (* 1024 2)) ; 2 MB/s
  17949. (alt-speed-up 512) ; 512 kB/s
  17950. (alt-speed-time-enabled? #t)
  17951. (alt-speed-time-day 'weekdays)
  17952. (alt-speed-time-begin
  17953. (+ (* 60 8) 30)) ; 8:30 am
  17954. (alt-speed-time-end
  17955. (+ (* 60 (+ 12 5)) 30)))) ; 5:30 pm
  17956. @end lisp
  17957. @end deffn
  17958. Once the service is started, users can interact with the daemon through
  17959. its Web interface (at @code{http://localhost:9091/}) or by using the
  17960. @command{transmission-remote} command-line tool, available in the
  17961. @code{transmission} package. (Emacs users may want to also consider the
  17962. @code{emacs-transmission} package.) Both communicate with the daemon
  17963. through its remote procedure call (RPC) interface, which by default is
  17964. available to all users on the system; you may wish to change this by
  17965. assigning values to the @code{rpc-authentication-required?},
  17966. @code{rpc-username} and @code{rpc-password} settings, as shown in the
  17967. example above and documented further below.
  17968. The value for @code{rpc-password} must be a password hash of the type
  17969. generated and used by Transmission clients. This can be copied verbatim
  17970. from an existing @file{settings.json} file, if another Transmission
  17971. client is already being used. Otherwise, the
  17972. @code{transmission-password-hash} and @code{transmission-random-salt}
  17973. procedures provided by this module can be used to obtain a suitable hash
  17974. value.
  17975. @deffn {Scheme Procedure} transmission-password-hash @var{password} @var{salt}
  17976. Returns a string containing the result of hashing @var{password}
  17977. together with @var{salt}, in the format recognized by Transmission
  17978. clients for their @code{rpc-password} configuration setting.
  17979. @var{salt} must be an eight-character string. The
  17980. @code{transmission-random-salt} procedure can be used to generate a
  17981. suitable salt value at random.
  17982. @end deffn
  17983. @deffn {Scheme Procedure} transmission-random-salt
  17984. Returns a string containing a random, eight-character salt value of the
  17985. type generated and used by Transmission clients, suitable for passing to
  17986. the @code{transmission-password-hash} procedure.
  17987. @end deffn
  17988. These procedures are accessible from within a Guile REPL started with
  17989. the @command{guix repl} command (@pxref{Invoking guix repl}). This is
  17990. useful for obtaining a random salt value to provide as the second
  17991. parameter to `transmission-password-hash`, as in this example session:
  17992. @example
  17993. $ guix repl
  17994. scheme@@(guix-user)> ,use (gnu services file-sharing)
  17995. scheme@@(guix-user)> (transmission-random-salt)
  17996. $1 = "uKd1uMs9"
  17997. @end example
  17998. Alternatively, a complete password hash can generated in a single step:
  17999. @example
  18000. scheme@@(guix-user)> (transmission-password-hash "transmission"
  18001. (transmission-random-salt))
  18002. $2 = "@{c8bbc6d1740cd8dc819a6e25563b67812c1c19c9VtFPfdsX"
  18003. @end example
  18004. The resulting string can be used as-is for the value of
  18005. @code{rpc-password}, allowing the password to be kept hidden even in the
  18006. operating-system configuration.
  18007. Torrent files downloaded by the daemon are directly accessible only to
  18008. users in the ``transmission'' user group, who receive read-only access
  18009. to the directory specified by the @code{download-dir} configuration
  18010. setting (and also the directory specified by @code{incomplete-dir}, if
  18011. @code{incomplete-dir-enabled?} is @code{#t}). Downloaded files can be
  18012. moved to another directory or deleted altogether using
  18013. @command{transmission-remote} with its @code{--move} and
  18014. @code{--remove-and-delete} options.
  18015. If the @code{watch-dir-enabled?} setting is set to @code{#t}, users in
  18016. the ``transmission'' group are able also to place @file{.torrent} files
  18017. in the directory specified by @code{watch-dir} to have the corresponding
  18018. torrents added by the daemon. (The @code{trash-original-torrent-files?}
  18019. setting controls whether the daemon deletes these files after processing
  18020. them.)
  18021. Some of the daemon's configuration settings can be changed temporarily
  18022. by @command{transmission-remote} and similar tools. To undo these
  18023. changes, use the service's @code{reload} action to have the daemon
  18024. reload its settings from disk:
  18025. @example
  18026. # herd reload transmission-daemon
  18027. @end example
  18028. The full set of available configuration settings is defined by the
  18029. @code{transmission-daemon-configuration} data type.
  18030. @deftp {Data Type} transmission-daemon-configuration
  18031. The data type representing configuration settings for Transmission
  18032. Daemon. These correspond directly to the settings recognized by
  18033. Transmission clients in their @file{settings.json} file.
  18034. @end deftp
  18035. @c The following documentation was initially generated by
  18036. @c (generate-transmission-daemon-documentation) in (gnu services
  18037. @c file-sharing). Manually maintained documentation is better, so we
  18038. @c shouldn't hesitate to edit below as needed. However if the change
  18039. @c you want to make to this documentation can be done in an automated
  18040. @c way, it's probably easier to change (generate-documentation) than to
  18041. @c make it below and have to deal with the churn as Transmission Daemon
  18042. @c updates.
  18043. @c %start of fragment
  18044. Available @code{transmission-daemon-configuration} fields are:
  18045. @deftypevr {@code{transmission-daemon-configuration} parameter} package transmission
  18046. The Transmission package to use.
  18047. @end deftypevr
  18048. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer stop-wait-period
  18049. The period, in seconds, to wait when stopping the service for
  18050. @command{transmission-daemon} to exit before killing its process. This
  18051. allows the daemon time to complete its housekeeping and send a final
  18052. update to trackers as it shuts down. On slow hosts, or hosts with a
  18053. slow network connection, this value may need to be increased.
  18054. Defaults to @samp{10}.
  18055. @end deftypevr
  18056. @deftypevr {@code{transmission-daemon-configuration} parameter} string download-dir
  18057. The directory to which torrent files are downloaded.
  18058. Defaults to @samp{"/var/lib/transmission-daemon/downloads"}.
  18059. @end deftypevr
  18060. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean incomplete-dir-enabled?
  18061. If @code{#t}, files will be held in @code{incomplete-dir} while their
  18062. torrent is being downloaded, then moved to @code{download-dir} once the
  18063. torrent is complete. Otherwise, files for all torrents (including those
  18064. still being downloaded) will be placed in @code{download-dir}.
  18065. Defaults to @samp{#f}.
  18066. @end deftypevr
  18067. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string incomplete-dir
  18068. The directory in which files from incompletely downloaded torrents will
  18069. be held when @code{incomplete-dir-enabled?} is @code{#t}.
  18070. Defaults to @samp{disabled}.
  18071. @end deftypevr
  18072. @deftypevr {@code{transmission-daemon-configuration} parameter} umask umask
  18073. The file mode creation mask used for downloaded files. (See the
  18074. @command{umask} man page for more information.)
  18075. Defaults to @samp{18}.
  18076. @end deftypevr
  18077. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rename-partial-files?
  18078. When @code{#t}, ``.part'' is appended to the name of partially
  18079. downloaded files.
  18080. Defaults to @samp{#t}.
  18081. @end deftypevr
  18082. @deftypevr {@code{transmission-daemon-configuration} parameter} preallocation-mode preallocation
  18083. The mode by which space should be preallocated for downloaded files, one
  18084. of @code{none}, @code{fast} (or @code{sparse}) and @code{full}.
  18085. Specifying @code{full} will minimize disk fragmentation at a cost to
  18086. file-creation speed.
  18087. Defaults to @samp{fast}.
  18088. @end deftypevr
  18089. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean watch-dir-enabled?
  18090. If @code{#t}, the directory specified by @code{watch-dir} will be
  18091. watched for new @file{.torrent} files and the torrents they describe
  18092. added automatically (and the original files removed, if
  18093. @code{trash-original-torrent-files?} is @code{#t}).
  18094. Defaults to @samp{#f}.
  18095. @end deftypevr
  18096. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string watch-dir
  18097. The directory to be watched for @file{.torrent} files indicating new
  18098. torrents to be added, when @code{watch-dir-enabled} is @code{#t}.
  18099. Defaults to @samp{disabled}.
  18100. @end deftypevr
  18101. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean trash-original-torrent-files?
  18102. When @code{#t}, @file{.torrent} files will be deleted from the watch
  18103. directory once their torrent has been added (see
  18104. @code{watch-directory-enabled?}).
  18105. Defaults to @samp{#f}.
  18106. @end deftypevr
  18107. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-down-enabled?
  18108. When @code{#t}, the daemon's download speed will be limited to the rate
  18109. specified by @code{speed-limit-down}.
  18110. Defaults to @samp{#f}.
  18111. @end deftypevr
  18112. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-down
  18113. The default global-maximum download speed, in kilobytes per second.
  18114. Defaults to @samp{100}.
  18115. @end deftypevr
  18116. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-up-enabled?
  18117. When @code{#t}, the daemon's upload speed will be limited to the rate
  18118. specified by @code{speed-limit-up}.
  18119. Defaults to @samp{#f}.
  18120. @end deftypevr
  18121. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-up
  18122. The default global-maximum upload speed, in kilobytes per second.
  18123. Defaults to @samp{100}.
  18124. @end deftypevr
  18125. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-enabled?
  18126. When @code{#t}, the alternate speed limits @code{alt-speed-down} and
  18127. @code{alt-speed-up} are used (in place of @code{speed-limit-down} and
  18128. @code{speed-limit-up}, if they are enabled) to constrain the daemon's
  18129. bandwidth usage. This can be scheduled to occur automatically at
  18130. certain times during the week; see @code{alt-speed-time-enabled?}.
  18131. Defaults to @samp{#f}.
  18132. @end deftypevr
  18133. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-down
  18134. The alternate global-maximum download speed, in kilobytes per second.
  18135. Defaults to @samp{50}.
  18136. @end deftypevr
  18137. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-up
  18138. The alternate global-maximum upload speed, in kilobytes per second.
  18139. Defaults to @samp{50}.
  18140. @end deftypevr
  18141. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-time-enabled?
  18142. When @code{#t}, the alternate speed limits @code{alt-speed-down} and
  18143. @code{alt-speed-up} will be enabled automatically during the periods
  18144. specified by @code{alt-speed-time-day}, @code{alt-speed-time-begin} and
  18145. @code{alt-time-speed-end}.
  18146. Defaults to @samp{#f}.
  18147. @end deftypevr
  18148. @deftypevr {@code{transmission-daemon-configuration} parameter} day-list alt-speed-time-day
  18149. The days of the week on which the alternate-speed schedule should be
  18150. used, specified either as a list of days (@code{sunday}, @code{monday},
  18151. and so on) or using one of the symbols @code{weekdays}, @code{weekends}
  18152. or @code{all}.
  18153. Defaults to @samp{all}.
  18154. @end deftypevr
  18155. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-begin
  18156. The time of day at which to enable the alternate speed limits, expressed
  18157. as a number of minutes since midnight.
  18158. Defaults to @samp{540}.
  18159. @end deftypevr
  18160. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-end
  18161. The time of day at which to disable the alternate speed limits,
  18162. expressed as a number of minutes since midnight.
  18163. Defaults to @samp{1020}.
  18164. @end deftypevr
  18165. @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv4
  18166. The IP address at which to listen for peer connections, or ``0.0.0.0''
  18167. to listen at all available IP addresses.
  18168. Defaults to @samp{"0.0.0.0"}.
  18169. @end deftypevr
  18170. @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv6
  18171. The IPv6 address at which to listen for peer connections, or ``::'' to
  18172. listen at all available IPv6 addresses.
  18173. Defaults to @samp{"::"}.
  18174. @end deftypevr
  18175. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean peer-port-random-on-start?
  18176. If @code{#t}, when the daemon starts it will select a port at random on
  18177. which to listen for peer connections, from the range specified
  18178. (inclusively) by @code{peer-port-random-low} and
  18179. @code{peer-port-random-high}. Otherwise, it listens on the port
  18180. specified by @code{peer-port}.
  18181. Defaults to @samp{#f}.
  18182. @end deftypevr
  18183. @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-low
  18184. The lowest selectable port number when @code{peer-port-random-on-start?}
  18185. is @code{#t}.
  18186. Defaults to @samp{49152}.
  18187. @end deftypevr
  18188. @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-high
  18189. The highest selectable port number when @code{peer-port-random-on-start}
  18190. is @code{#t}.
  18191. Defaults to @samp{65535}.
  18192. @end deftypevr
  18193. @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port
  18194. The port on which to listen for peer connections when
  18195. @code{peer-port-random-on-start?} is @code{#f}.
  18196. Defaults to @samp{51413}.
  18197. @end deftypevr
  18198. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean port-forwarding-enabled?
  18199. If @code{#t}, the daemon will attempt to configure port-forwarding on an
  18200. upstream gateway automatically using @acronym{UPnP} and
  18201. @acronym{NAT-PMP}.
  18202. Defaults to @samp{#t}.
  18203. @end deftypevr
  18204. @deftypevr {@code{transmission-daemon-configuration} parameter} encryption-mode encryption
  18205. The encryption preference for peer connections, one of
  18206. @code{prefer-unencrypted-connections},
  18207. @code{prefer-encrypted-connections} or
  18208. @code{require-encrypted-connections}.
  18209. Defaults to @samp{prefer-encrypted-connections}.
  18210. @end deftypevr
  18211. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string peer-congestion-algorithm
  18212. The TCP congestion-control algorithm to use for peer connections,
  18213. specified using a string recognized by the operating system in calls to
  18214. @code{setsockopt} (or set to @code{disabled}, in which case the
  18215. operating-system default is used).
  18216. Note that on GNU/Linux systems, the kernel must be configured to allow
  18217. processes to use a congestion-control algorithm not in the default set;
  18218. otherwise, it will deny these requests with ``Operation not permitted''.
  18219. To see which algorithms are available on your system and which are
  18220. currently permitted for use, look at the contents of the files
  18221. @file{tcp_available_congestion_control} and
  18222. @file{tcp_allowed_congestion_control} in the @file{/proc/sys/net/ipv4}
  18223. directory.
  18224. As an example, to have Transmission Daemon use
  18225. @uref{http://www-ece.rice.edu/networks/TCP-LP/,the TCP Low Priority
  18226. congestion-control algorithm}, you'll need to modify your kernel
  18227. configuration to build in support for the algorithm, then update your
  18228. operating-system configuration to allow its use by adding a
  18229. @code{sysctl-service-type} service (or updating the existing one's
  18230. configuration) with lines like the following:
  18231. @lisp
  18232. (service sysctl-service-type
  18233. (sysctl-configuration
  18234. (settings
  18235. ("net.ipv4.tcp_allowed_congestion_control" .
  18236. "reno cubic lp"))))
  18237. @end lisp
  18238. The Transmission Daemon configuration can then be updated with
  18239. @lisp
  18240. (peer-congestion-algorithm "lp")
  18241. @end lisp
  18242. and the system reconfigured to have the changes take effect.
  18243. Defaults to @samp{disabled}.
  18244. @end deftypevr
  18245. @deftypevr {@code{transmission-daemon-configuration} parameter} tcp-type-of-service peer-socket-tos
  18246. The type of service to request in outgoing @acronym{TCP} packets, one of
  18247. @code{default}, @code{low-cost}, @code{throughput}, @code{low-delay} and
  18248. @code{reliability}.
  18249. Defaults to @samp{default}.
  18250. @end deftypevr
  18251. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-global
  18252. The global limit on the number of connected peers.
  18253. Defaults to @samp{200}.
  18254. @end deftypevr
  18255. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-per-torrent
  18256. The per-torrent limit on the number of connected peers.
  18257. Defaults to @samp{50}.
  18258. @end deftypevr
  18259. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer upload-slots-per-torrent
  18260. The maximum number of peers to which the daemon will upload data
  18261. simultaneously for each torrent.
  18262. Defaults to @samp{14}.
  18263. @end deftypevr
  18264. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-id-ttl-hours
  18265. The maximum lifespan, in hours, of the peer ID associated with each
  18266. public torrent before it is regenerated.
  18267. Defaults to @samp{6}.
  18268. @end deftypevr
  18269. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean blocklist-enabled?
  18270. When @code{#t}, the daemon will ignore peers mentioned in the blocklist
  18271. it has most recently downloaded from @code{blocklist-url}.
  18272. Defaults to @samp{#f}.
  18273. @end deftypevr
  18274. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string blocklist-url
  18275. The URL of a peer blocklist (in @acronym{P2P}-plaintext or eMule
  18276. @file{.dat} format) to be periodically downloaded and applied when
  18277. @code{blocklist-enabled?} is @code{#t}.
  18278. Defaults to @samp{disabled}.
  18279. @end deftypevr
  18280. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean download-queue-enabled?
  18281. If @code{#t}, the daemon will be limited to downloading at most
  18282. @code{download-queue-size} non-stalled torrents simultaneously.
  18283. Defaults to @samp{#t}.
  18284. @end deftypevr
  18285. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer download-queue-size
  18286. The size of the daemon's download queue, which limits the number of
  18287. non-stalled torrents it will download at any one time when
  18288. @code{download-queue-enabled?} is @code{#t}.
  18289. Defaults to @samp{5}.
  18290. @end deftypevr
  18291. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean seed-queue-enabled?
  18292. If @code{#t}, the daemon will be limited to seeding at most
  18293. @code{seed-queue-size} non-stalled torrents simultaneously.
  18294. Defaults to @samp{#f}.
  18295. @end deftypevr
  18296. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer seed-queue-size
  18297. The size of the daemon's seed queue, which limits the number of
  18298. non-stalled torrents it will seed at any one time when
  18299. @code{seed-queue-enabled?} is @code{#t}.
  18300. Defaults to @samp{10}.
  18301. @end deftypevr
  18302. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean queue-stalled-enabled?
  18303. When @code{#t}, the daemon will consider torrents for which it has not
  18304. shared data in the past @code{queue-stalled-minutes} minutes to be
  18305. stalled and not count them against its @code{download-queue-size} and
  18306. @code{seed-queue-size} limits.
  18307. Defaults to @samp{#t}.
  18308. @end deftypevr
  18309. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer queue-stalled-minutes
  18310. The maximum period, in minutes, a torrent may be idle before it is
  18311. considered to be stalled, when @code{queue-stalled-enabled?} is
  18312. @code{#t}.
  18313. Defaults to @samp{30}.
  18314. @end deftypevr
  18315. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean ratio-limit-enabled?
  18316. When @code{#t}, a torrent being seeded will automatically be paused once
  18317. it reaches the ratio specified by @code{ratio-limit}.
  18318. Defaults to @samp{#f}.
  18319. @end deftypevr
  18320. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-rational ratio-limit
  18321. The ratio at which a torrent being seeded will be paused, when
  18322. @code{ratio-limit-enabled?} is @code{#t}.
  18323. Defaults to @samp{2.0}.
  18324. @end deftypevr
  18325. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean idle-seeding-limit-enabled?
  18326. When @code{#t}, a torrent being seeded will automatically be paused once
  18327. it has been idle for @code{idle-seeding-limit} minutes.
  18328. Defaults to @samp{#f}.
  18329. @end deftypevr
  18330. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer idle-seeding-limit
  18331. The maximum period, in minutes, a torrent being seeded may be idle
  18332. before it is paused, when @code{idle-seeding-limit-enabled?} is
  18333. @code{#t}.
  18334. Defaults to @samp{30}.
  18335. @end deftypevr
  18336. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean dht-enabled?
  18337. Enable @uref{http://bittorrent.org/beps/bep_0005.html,the distributed
  18338. hash table (@acronym{DHT}) protocol}, which supports the use of
  18339. trackerless torrents.
  18340. Defaults to @samp{#t}.
  18341. @end deftypevr
  18342. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean lpd-enabled?
  18343. Enable @uref{https://en.wikipedia.org/wiki/Local_Peer_Discovery,local
  18344. peer discovery} (@acronym{LPD}), which allows the discovery of peers on
  18345. the local network and may reduce the amount of data sent over the public
  18346. Internet.
  18347. Defaults to @samp{#f}.
  18348. @end deftypevr
  18349. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean pex-enabled?
  18350. Enable @uref{https://en.wikipedia.org/wiki/Peer_exchange,peer exchange}
  18351. (@acronym{PEX}), which reduces the daemon's reliance on external
  18352. trackers and may improve its performance.
  18353. Defaults to @samp{#t}.
  18354. @end deftypevr
  18355. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean utp-enabled?
  18356. Enable @uref{http://bittorrent.org/beps/bep_0029.html,the micro
  18357. transport protocol} (@acronym{uTP}), which aims to reduce the impact of
  18358. BitTorrent traffic on other users of the local network while maintaining
  18359. full utilization of the available bandwidth.
  18360. Defaults to @samp{#t}.
  18361. @end deftypevr
  18362. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-enabled?
  18363. If @code{#t}, enable the remote procedure call (@acronym{RPC})
  18364. interface, which allows remote control of the daemon via its Web
  18365. interface, the @command{transmission-remote} command-line client, and
  18366. similar tools.
  18367. Defaults to @samp{#t}.
  18368. @end deftypevr
  18369. @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-bind-address
  18370. The IP address at which to listen for @acronym{RPC} connections, or
  18371. ``0.0.0.0'' to listen at all available IP addresses.
  18372. Defaults to @samp{"0.0.0.0"}.
  18373. @end deftypevr
  18374. @deftypevr {@code{transmission-daemon-configuration} parameter} port-number rpc-port
  18375. The port on which to listen for @acronym{RPC} connections.
  18376. Defaults to @samp{9091}.
  18377. @end deftypevr
  18378. @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-url
  18379. The path prefix to use in the @acronym{RPC}-endpoint @acronym{URL}.
  18380. Defaults to @samp{"/transmission/"}.
  18381. @end deftypevr
  18382. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-authentication-required?
  18383. When @code{#t}, clients must authenticate (see @code{rpc-username} and
  18384. @code{rpc-password}) when using the @acronym{RPC} interface. Note this
  18385. has the side effect of disabling host-name whitelisting (see
  18386. @code{rpc-host-whitelist-enabled?}.
  18387. Defaults to @samp{#f}.
  18388. @end deftypevr
  18389. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string rpc-username
  18390. The username required by clients to access the @acronym{RPC} interface
  18391. when @code{rpc-authentication-required?} is @code{#t}.
  18392. Defaults to @samp{disabled}.
  18393. @end deftypevr
  18394. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-transmission-password-hash rpc-password
  18395. The password required by clients to access the @acronym{RPC} interface
  18396. when @code{rpc-authentication-required?} is @code{#t}. This must be
  18397. specified using a password hash in the format recognized by Transmission
  18398. clients, either copied from an existing @file{settings.json} file or
  18399. generated using the @code{transmission-password-hash} procedure.
  18400. Defaults to @samp{disabled}.
  18401. @end deftypevr
  18402. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-whitelist-enabled?
  18403. When @code{#t}, @acronym{RPC} requests will be accepted only when they
  18404. originate from an address specified in @code{rpc-whitelist}.
  18405. Defaults to @samp{#t}.
  18406. @end deftypevr
  18407. @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-whitelist
  18408. The list of IP and IPv6 addresses from which @acronym{RPC} requests will
  18409. be accepted when @code{rpc-whitelist-enabled?} is @code{#t}. Wildcards
  18410. may be specified using @samp{*}.
  18411. Defaults to @samp{("127.0.0.1" "::1")}.
  18412. @end deftypevr
  18413. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-host-whitelist-enabled?
  18414. When @code{#t}, @acronym{RPC} requests will be accepted only when they
  18415. are addressed to a host named in @code{rpc-host-whitelist}. Note that
  18416. requests to ``localhost'' or ``localhost.'', or to a numeric address,
  18417. are always accepted regardless of these settings.
  18418. Note also this functionality is disabled when
  18419. @code{rpc-authentication-required?} is @code{#t}.
  18420. Defaults to @samp{#t}.
  18421. @end deftypevr
  18422. @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-host-whitelist
  18423. The list of host names recognized by the @acronym{RPC} server when
  18424. @code{rpc-host-whitelist-enabled?} is @code{#t}.
  18425. Defaults to @samp{()}.
  18426. @end deftypevr
  18427. @deftypevr {@code{transmission-daemon-configuration} parameter} message-level message-level
  18428. The minimum severity level of messages to be logged (to
  18429. @file{/var/log/transmission.log}) by the daemon, one of @code{none} (no
  18430. logging), @code{error}, @code{info} and @code{debug}.
  18431. Defaults to @samp{info}.
  18432. @end deftypevr
  18433. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean start-added-torrents?
  18434. When @code{#t}, torrents are started as soon as they are added;
  18435. otherwise, they are added in ``paused'' state.
  18436. Defaults to @samp{#t}.
  18437. @end deftypevr
  18438. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean script-torrent-done-enabled?
  18439. When @code{#t}, the script specified by
  18440. @code{script-torrent-done-filename} will be invoked each time a torrent
  18441. completes.
  18442. Defaults to @samp{#f}.
  18443. @end deftypevr
  18444. @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-file-object script-torrent-done-filename
  18445. A file name or file-like object specifying a script to run each time a
  18446. torrent completes, when @code{script-torrent-done-enabled?} is
  18447. @code{#t}.
  18448. Defaults to @samp{disabled}.
  18449. @end deftypevr
  18450. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean scrape-paused-torrents-enabled?
  18451. When @code{#t}, the daemon will scrape trackers for a torrent even when
  18452. the torrent is paused.
  18453. Defaults to @samp{#t}.
  18454. @end deftypevr
  18455. @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer cache-size-mb
  18456. The amount of memory, in megabytes, to allocate for the daemon's
  18457. in-memory cache. A larger value may increase performance by reducing
  18458. the frequency of disk I/O.
  18459. Defaults to @samp{4}.
  18460. @end deftypevr
  18461. @deftypevr {@code{transmission-daemon-configuration} parameter} boolean prefetch-enabled?
  18462. When @code{#t}, the daemon will try to improve I/O performance by
  18463. hinting to the operating system which data is likely to be read next
  18464. from disk to satisfy requests from peers.
  18465. Defaults to @samp{#t}.
  18466. @end deftypevr
  18467. @c %end of fragment
  18468. @node Monitoring Services
  18469. @subsection Monitoring Services
  18470. @subsubheading Tailon Service
  18471. @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
  18472. viewing and searching log files.
  18473. The following example will configure the service with default values.
  18474. By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
  18475. @lisp
  18476. (service tailon-service-type)
  18477. @end lisp
  18478. The following example customises more of the Tailon configuration,
  18479. adding @command{sed} to the list of allowed commands.
  18480. @lisp
  18481. (service tailon-service-type
  18482. (tailon-configuration
  18483. (config-file
  18484. (tailon-configuration-file
  18485. (allowed-commands '("tail" "grep" "awk" "sed"))))))
  18486. @end lisp
  18487. @deftp {Data Type} tailon-configuration
  18488. Data type representing the configuration of Tailon.
  18489. This type has the following parameters:
  18490. @table @asis
  18491. @item @code{config-file} (default: @code{(tailon-configuration-file)})
  18492. The configuration file to use for Tailon. This can be set to a
  18493. @dfn{tailon-configuration-file} record value, or any gexp
  18494. (@pxref{G-Expressions}).
  18495. For example, to instead use a local file, the @code{local-file} function
  18496. can be used:
  18497. @lisp
  18498. (service tailon-service-type
  18499. (tailon-configuration
  18500. (config-file (local-file "./my-tailon.conf"))))
  18501. @end lisp
  18502. @item @code{package} (default: @code{tailon})
  18503. The tailon package to use.
  18504. @end table
  18505. @end deftp
  18506. @deftp {Data Type} tailon-configuration-file
  18507. Data type representing the configuration options for Tailon.
  18508. This type has the following parameters:
  18509. @table @asis
  18510. @item @code{files} (default: @code{(list "/var/log")})
  18511. List of files to display. The list can include strings for a single file
  18512. or directory, or a list, where the first item is the name of a
  18513. subsection, and the remaining items are the files or directories in that
  18514. subsection.
  18515. @item @code{bind} (default: @code{"localhost:8080"})
  18516. Address and port to which Tailon should bind on.
  18517. @item @code{relative-root} (default: @code{#f})
  18518. URL path to use for Tailon, set to @code{#f} to not use a path.
  18519. @item @code{allow-transfers?} (default: @code{#t})
  18520. Allow downloading the log files in the web interface.
  18521. @item @code{follow-names?} (default: @code{#t})
  18522. Allow tailing of not-yet existent files.
  18523. @item @code{tail-lines} (default: @code{200})
  18524. Number of lines to read initially from each file.
  18525. @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
  18526. Commands to allow running. By default, @code{sed} is disabled.
  18527. @item @code{debug?} (default: @code{#f})
  18528. Set @code{debug?} to @code{#t} to show debug messages.
  18529. @item @code{wrap-lines} (default: @code{#t})
  18530. Initial line wrapping state in the web interface. Set to @code{#t} to
  18531. initially wrap lines (the default), or to @code{#f} to initially not
  18532. wrap lines.
  18533. @item @code{http-auth} (default: @code{#f})
  18534. HTTP authentication type to use. Set to @code{#f} to disable
  18535. authentication (the default). Supported values are @code{"digest"} or
  18536. @code{"basic"}.
  18537. @item @code{users} (default: @code{#f})
  18538. If HTTP authentication is enabled (see @code{http-auth}), access will be
  18539. restricted to the credentials provided here. To configure users, use a
  18540. list of pairs, where the first element of the pair is the username, and
  18541. the 2nd element of the pair is the password.
  18542. @lisp
  18543. (tailon-configuration-file
  18544. (http-auth "basic")
  18545. (users '(("user1" . "password1")
  18546. ("user2" . "password2"))))
  18547. @end lisp
  18548. @end table
  18549. @end deftp
  18550. @subsubheading Darkstat Service
  18551. @cindex darkstat
  18552. Darkstat is a packet sniffer that captures network traffic, calculates
  18553. statistics about usage, and serves reports over HTTP.
  18554. @defvar {Scheme Variable} darkstat-service-type
  18555. This is the service type for the
  18556. @uref{https://unix4lyfe.org/darkstat/, darkstat}
  18557. service, its value must be a @code{darkstat-configuration} record as in
  18558. this example:
  18559. @lisp
  18560. (service darkstat-service-type
  18561. (darkstat-configuration
  18562. (interface "eno1")))
  18563. @end lisp
  18564. @end defvar
  18565. @deftp {Data Type} darkstat-configuration
  18566. Data type representing the configuration of @command{darkstat}.
  18567. @table @asis
  18568. @item @code{package} (default: @code{darkstat})
  18569. The darkstat package to use.
  18570. @item @code{interface}
  18571. Capture traffic on the specified network interface.
  18572. @item @code{port} (default: @code{"667"})
  18573. Bind the web interface to the specified port.
  18574. @item @code{bind-address} (default: @code{"127.0.0.1"})
  18575. Bind the web interface to the specified address.
  18576. @item @code{base} (default: @code{"/"})
  18577. Specify the path of the base URL@. This can be useful if
  18578. @command{darkstat} is accessed via a reverse proxy.
  18579. @end table
  18580. @end deftp
  18581. @subsubheading Prometheus Node Exporter Service
  18582. @cindex prometheus-node-exporter
  18583. The Prometheus ``node exporter'' makes hardware and operating system statistics
  18584. provided by the Linux kernel available for the Prometheus monitoring system.
  18585. This service should be deployed on all physical nodes and virtual machines,
  18586. where monitoring these statistics is desirable.
  18587. @defvar {Scheme variable} prometheus-node-exporter-service-type
  18588. This is the service type for the
  18589. @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
  18590. service, its value must be a @code{prometheus-node-exporter-configuration}.
  18591. @lisp
  18592. (service prometheus-node-exporter-service-type)
  18593. @end lisp
  18594. @end defvar
  18595. @deftp {Data Type} prometheus-node-exporter-configuration
  18596. Data type representing the configuration of @command{node_exporter}.
  18597. @table @asis
  18598. @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
  18599. The prometheus-node-exporter package to use.
  18600. @item @code{web-listen-address} (default: @code{":9100"})
  18601. Bind the web interface to the specified address.
  18602. @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
  18603. This directory can be used to export metrics specific to this machine.
  18604. Files containing metrics in the text format, with the filename ending in
  18605. @code{.prom} should be placed in this directory.
  18606. @item @code{extra-options} (default: @code{'()})
  18607. Extra options to pass to the Prometheus node exporter.
  18608. @end table
  18609. @end deftp
  18610. @subsubheading Zabbix server
  18611. @cindex zabbix zabbix-server
  18612. Zabbix provides monitoring metrics, among others network utilization, CPU load
  18613. and disk space consumption:
  18614. @itemize
  18615. @item High performance, high capacity (able to monitor hundreds of thousands of devices).
  18616. @item Auto-discovery of servers and network devices and interfaces.
  18617. @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
  18618. @item Distributed monitoring with centralized web administration.
  18619. @item Native high performance agents.
  18620. @item SLA, and ITIL KPI metrics on reporting.
  18621. @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
  18622. @item Remote command execution through Zabbix proxies.
  18623. @end itemize
  18624. @c %start of fragment
  18625. Available @code{zabbix-server-configuration} fields are:
  18626. @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
  18627. The zabbix-server package.
  18628. @end deftypevr
  18629. @deftypevr {@code{zabbix-server-configuration} parameter} string user
  18630. User who will run the Zabbix server.
  18631. Defaults to @samp{"zabbix"}.
  18632. @end deftypevr
  18633. @deftypevr {@code{zabbix-server-configuration} parameter} group group
  18634. Group who will run the Zabbix server.
  18635. Defaults to @samp{"zabbix"}.
  18636. @end deftypevr
  18637. @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
  18638. Database host name.
  18639. Defaults to @samp{"127.0.0.1"}.
  18640. @end deftypevr
  18641. @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
  18642. Database name.
  18643. Defaults to @samp{"zabbix"}.
  18644. @end deftypevr
  18645. @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
  18646. Database user.
  18647. Defaults to @samp{"zabbix"}.
  18648. @end deftypevr
  18649. @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
  18650. Database password. Please, use @code{include-files} with
  18651. @code{DBPassword=SECRET} inside a specified file instead.
  18652. Defaults to @samp{""}.
  18653. @end deftypevr
  18654. @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
  18655. Database port.
  18656. Defaults to @samp{5432}.
  18657. @end deftypevr
  18658. @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
  18659. Specifies where log messages are written to:
  18660. @itemize @bullet
  18661. @item
  18662. @code{system} - syslog.
  18663. @item
  18664. @code{file} - file specified with @code{log-file} parameter.
  18665. @item
  18666. @code{console} - standard output.
  18667. @end itemize
  18668. Defaults to @samp{""}.
  18669. @end deftypevr
  18670. @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
  18671. Log file name for @code{log-type} @code{file} parameter.
  18672. Defaults to @samp{"/var/log/zabbix/server.log"}.
  18673. @end deftypevr
  18674. @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
  18675. Name of PID file.
  18676. Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
  18677. @end deftypevr
  18678. @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
  18679. The location of certificate authority (CA) files for SSL server
  18680. certificate verification.
  18681. Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
  18682. @end deftypevr
  18683. @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
  18684. Location of SSL client certificates.
  18685. Defaults to @samp{"/etc/ssl/certs"}.
  18686. @end deftypevr
  18687. @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
  18688. Extra options will be appended to Zabbix server configuration file.
  18689. Defaults to @samp{""}.
  18690. @end deftypevr
  18691. @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
  18692. You may include individual files or all files in a directory in the
  18693. configuration file.
  18694. Defaults to @samp{()}.
  18695. @end deftypevr
  18696. @c %end of fragment
  18697. @subsubheading Zabbix agent
  18698. @cindex zabbix zabbix-agent
  18699. Zabbix agent gathers information for Zabbix server.
  18700. @c %start of fragment
  18701. Available @code{zabbix-agent-configuration} fields are:
  18702. @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
  18703. The zabbix-agent package.
  18704. @end deftypevr
  18705. @deftypevr {@code{zabbix-agent-configuration} parameter} string user
  18706. User who will run the Zabbix agent.
  18707. Defaults to @samp{"zabbix"}.
  18708. @end deftypevr
  18709. @deftypevr {@code{zabbix-agent-configuration} parameter} group group
  18710. Group who will run the Zabbix agent.
  18711. Defaults to @samp{"zabbix"}.
  18712. @end deftypevr
  18713. @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
  18714. Unique, case sensitive hostname which is required for active checks and
  18715. must match hostname as configured on the server.
  18716. Defaults to @samp{""}.
  18717. @end deftypevr
  18718. @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
  18719. Specifies where log messages are written to:
  18720. @itemize @bullet
  18721. @item
  18722. @code{system} - syslog.
  18723. @item
  18724. @code{file} - file specified with @code{log-file} parameter.
  18725. @item
  18726. @code{console} - standard output.
  18727. @end itemize
  18728. Defaults to @samp{""}.
  18729. @end deftypevr
  18730. @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
  18731. Log file name for @code{log-type} @code{file} parameter.
  18732. Defaults to @samp{"/var/log/zabbix/agent.log"}.
  18733. @end deftypevr
  18734. @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
  18735. Name of PID file.
  18736. Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
  18737. @end deftypevr
  18738. @deftypevr {@code{zabbix-agent-configuration} parameter} list server
  18739. List of IP addresses, optionally in CIDR notation, or hostnames of
  18740. Zabbix servers and Zabbix proxies. Incoming connections will be
  18741. accepted only from the hosts listed here.
  18742. Defaults to @samp{("127.0.0.1")}.
  18743. @end deftypevr
  18744. @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
  18745. List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
  18746. proxies for active checks. If port is not specified, default port is
  18747. used. If this parameter is not specified, active checks are disabled.
  18748. Defaults to @samp{("127.0.0.1")}.
  18749. @end deftypevr
  18750. @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
  18751. Extra options will be appended to Zabbix server configuration file.
  18752. Defaults to @samp{""}.
  18753. @end deftypevr
  18754. @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
  18755. You may include individual files or all files in a directory in the
  18756. configuration file.
  18757. Defaults to @samp{()}.
  18758. @end deftypevr
  18759. @c %end of fragment
  18760. @subsubheading Zabbix front-end
  18761. @cindex zabbix zabbix-front-end
  18762. This service provides a WEB interface to Zabbix server.
  18763. @c %start of fragment
  18764. Available @code{zabbix-front-end-configuration} fields are:
  18765. @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
  18766. NGINX configuration.
  18767. @end deftypevr
  18768. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
  18769. Database host name.
  18770. Defaults to @samp{"localhost"}.
  18771. @end deftypevr
  18772. @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
  18773. Database port.
  18774. Defaults to @samp{5432}.
  18775. @end deftypevr
  18776. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
  18777. Database name.
  18778. Defaults to @samp{"zabbix"}.
  18779. @end deftypevr
  18780. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
  18781. Database user.
  18782. Defaults to @samp{"zabbix"}.
  18783. @end deftypevr
  18784. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
  18785. Database password. Please, use @code{db-secret-file} instead.
  18786. Defaults to @samp{""}.
  18787. @end deftypevr
  18788. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
  18789. Secret file containing the credentials for the Zabbix front-end. The value
  18790. must be a local file name, not a G-expression. You are expected to create
  18791. this file manually. Its contents will be copied into @file{zabbix.conf.php}
  18792. as the value of @code{$DB['PASSWORD']}.
  18793. Defaults to @samp{""}.
  18794. @end deftypevr
  18795. @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
  18796. Zabbix server hostname.
  18797. Defaults to @samp{"localhost"}.
  18798. @end deftypevr
  18799. @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
  18800. Zabbix server port.
  18801. Defaults to @samp{10051}.
  18802. @end deftypevr
  18803. @c %end of fragment
  18804. @node Kerberos Services
  18805. @subsection Kerberos Services
  18806. @cindex Kerberos
  18807. The @code{(gnu services kerberos)} module provides services relating to
  18808. the authentication protocol @dfn{Kerberos}.
  18809. @subsubheading Krb5 Service
  18810. Programs using a Kerberos client library normally
  18811. expect a configuration file in @file{/etc/krb5.conf}.
  18812. This service generates such a file from a definition provided in the
  18813. operating system declaration.
  18814. It does not cause any daemon to be started.
  18815. No ``keytab'' files are provided by this service---you must explicitly create them.
  18816. This service is known to work with the MIT client library, @code{mit-krb5}.
  18817. Other implementations have not been tested.
  18818. @defvr {Scheme Variable} krb5-service-type
  18819. A service type for Kerberos 5 clients.
  18820. @end defvr
  18821. @noindent
  18822. Here is an example of its use:
  18823. @lisp
  18824. (service krb5-service-type
  18825. (krb5-configuration
  18826. (default-realm "EXAMPLE.COM")
  18827. (allow-weak-crypto? #t)
  18828. (realms (list
  18829. (krb5-realm
  18830. (name "EXAMPLE.COM")
  18831. (admin-server "groucho.example.com")
  18832. (kdc "karl.example.com"))
  18833. (krb5-realm
  18834. (name "ARGRX.EDU")
  18835. (admin-server "kerb-admin.argrx.edu")
  18836. (kdc "keys.argrx.edu"))))))
  18837. @end lisp
  18838. @noindent
  18839. This example provides a Kerberos@tie{}5 client configuration which:
  18840. @itemize
  18841. @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
  18842. of which have distinct administration servers and key distribution centers;
  18843. @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
  18844. specified by clients;
  18845. @item Accepts services which only support encryption types known to be weak.
  18846. @end itemize
  18847. The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
  18848. Only the most commonly used ones are described here.
  18849. For a full list, and more detailed explanation of each, see the MIT
  18850. @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
  18851. documentation.
  18852. @deftp {Data Type} krb5-realm
  18853. @cindex realm, kerberos
  18854. @table @asis
  18855. @item @code{name}
  18856. This field is a string identifying the name of the realm.
  18857. A common convention is to use the fully qualified DNS name of your organization,
  18858. converted to upper case.
  18859. @item @code{admin-server}
  18860. This field is a string identifying the host where the administration server is
  18861. running.
  18862. @item @code{kdc}
  18863. This field is a string identifying the key distribution center
  18864. for the realm.
  18865. @end table
  18866. @end deftp
  18867. @deftp {Data Type} krb5-configuration
  18868. @table @asis
  18869. @item @code{allow-weak-crypto?} (default: @code{#f})
  18870. If this flag is @code{#t} then services which only offer encryption algorithms
  18871. known to be weak will be accepted.
  18872. @item @code{default-realm} (default: @code{#f})
  18873. This field should be a string identifying the default Kerberos
  18874. realm for the client.
  18875. You should set this field to the name of your Kerberos realm.
  18876. If this value is @code{#f}
  18877. then a realm must be specified with every Kerberos principal when invoking programs
  18878. such as @command{kinit}.
  18879. @item @code{realms}
  18880. This should be a non-empty list of @code{krb5-realm} objects, which clients may
  18881. access.
  18882. Normally, one of them will have a @code{name} field matching the @code{default-realm}
  18883. field.
  18884. @end table
  18885. @end deftp
  18886. @subsubheading PAM krb5 Service
  18887. @cindex pam-krb5
  18888. The @code{pam-krb5} service allows for login authentication and password
  18889. management via Kerberos.
  18890. You will need this service if you want PAM enabled applications to authenticate
  18891. users using Kerberos.
  18892. @defvr {Scheme Variable} pam-krb5-service-type
  18893. A service type for the Kerberos 5 PAM module.
  18894. @end defvr
  18895. @deftp {Data Type} pam-krb5-configuration
  18896. Data type representing the configuration of the Kerberos 5 PAM module.
  18897. This type has the following parameters:
  18898. @table @asis
  18899. @item @code{pam-krb5} (default: @code{pam-krb5})
  18900. The pam-krb5 package to use.
  18901. @item @code{minimum-uid} (default: @code{1000})
  18902. The smallest user ID for which Kerberos authentications should be attempted.
  18903. Local accounts with lower values will silently fail to authenticate.
  18904. @end table
  18905. @end deftp
  18906. @node LDAP Services
  18907. @subsection LDAP Services
  18908. @cindex LDAP
  18909. @cindex nslcd, LDAP service
  18910. The @code{(gnu services authentication)} module provides the
  18911. @code{nslcd-service-type}, which can be used to authenticate against an LDAP
  18912. server. In addition to configuring the service itself, you may want to add
  18913. @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
  18914. Switch} for detailed information.
  18915. Here is a simple operating system declaration with a default configuration of
  18916. the @code{nslcd-service-type} and a Name Service Switch configuration that
  18917. consults the @code{ldap} name service last:
  18918. @lisp
  18919. (use-service-modules authentication)
  18920. (use-modules (gnu system nss))
  18921. ...
  18922. (operating-system
  18923. ...
  18924. (services
  18925. (cons*
  18926. (service nslcd-service-type)
  18927. (service dhcp-client-service-type)
  18928. %base-services))
  18929. (name-service-switch
  18930. (let ((services (list (name-service (name "db"))
  18931. (name-service (name "files"))
  18932. (name-service (name "ldap")))))
  18933. (name-service-switch
  18934. (inherit %mdns-host-lookup-nss)
  18935. (password services)
  18936. (shadow services)
  18937. (group services)
  18938. (netgroup services)
  18939. (gshadow services)))))
  18940. @end lisp
  18941. @c %start of generated documentation for nslcd-configuration
  18942. Available @code{nslcd-configuration} fields are:
  18943. @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
  18944. The @code{nss-pam-ldapd} package to use.
  18945. @end deftypevr
  18946. @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
  18947. The number of threads to start that can handle requests and perform LDAP
  18948. queries. Each thread opens a separate connection to the LDAP server.
  18949. The default is to start 5 threads.
  18950. Defaults to @samp{disabled}.
  18951. @end deftypevr
  18952. @deftypevr {@code{nslcd-configuration} parameter} string uid
  18953. This specifies the user id with which the daemon should be run.
  18954. Defaults to @samp{"nslcd"}.
  18955. @end deftypevr
  18956. @deftypevr {@code{nslcd-configuration} parameter} string gid
  18957. This specifies the group id with which the daemon should be run.
  18958. Defaults to @samp{"nslcd"}.
  18959. @end deftypevr
  18960. @deftypevr {@code{nslcd-configuration} parameter} log-option log
  18961. This option controls the way logging is done via a list containing
  18962. SCHEME and LEVEL@. The SCHEME argument may either be the symbols
  18963. @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
  18964. argument is optional and specifies the log level. The log level may be
  18965. one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
  18966. @samp{notice}, @samp{info} or @samp{debug}. All messages with the
  18967. specified log level or higher are logged.
  18968. Defaults to @samp{("/var/log/nslcd" info)}.
  18969. @end deftypevr
  18970. @deftypevr {@code{nslcd-configuration} parameter} list uri
  18971. The list of LDAP server URIs. Normally, only the first server will be
  18972. used with the following servers as fall-back.
  18973. Defaults to @samp{("ldap://localhost:389/")}.
  18974. @end deftypevr
  18975. @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
  18976. The version of the LDAP protocol to use. The default is to use the
  18977. maximum version supported by the LDAP library.
  18978. Defaults to @samp{disabled}.
  18979. @end deftypevr
  18980. @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
  18981. Specifies the distinguished name with which to bind to the directory
  18982. server for lookups. The default is to bind anonymously.
  18983. Defaults to @samp{disabled}.
  18984. @end deftypevr
  18985. @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
  18986. Specifies the credentials with which to bind. This option is only
  18987. applicable when used with binddn.
  18988. Defaults to @samp{disabled}.
  18989. @end deftypevr
  18990. @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
  18991. Specifies the distinguished name to use when the root user tries to
  18992. modify a user's password using the PAM module.
  18993. Defaults to @samp{disabled}.
  18994. @end deftypevr
  18995. @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
  18996. Specifies the credentials with which to bind if the root user tries to
  18997. change a user's password. This option is only applicable when used with
  18998. rootpwmoddn
  18999. Defaults to @samp{disabled}.
  19000. @end deftypevr
  19001. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
  19002. Specifies the SASL mechanism to be used when performing SASL
  19003. authentication.
  19004. Defaults to @samp{disabled}.
  19005. @end deftypevr
  19006. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
  19007. Specifies the SASL realm to be used when performing SASL authentication.
  19008. Defaults to @samp{disabled}.
  19009. @end deftypevr
  19010. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
  19011. Specifies the authentication identity to be used when performing SASL
  19012. authentication.
  19013. Defaults to @samp{disabled}.
  19014. @end deftypevr
  19015. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
  19016. Specifies the authorization identity to be used when performing SASL
  19017. authentication.
  19018. Defaults to @samp{disabled}.
  19019. @end deftypevr
  19020. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
  19021. Determines whether the LDAP server host name should be canonicalised. If
  19022. this is enabled the LDAP library will do a reverse host name lookup. By
  19023. default, it is left up to the LDAP library whether this check is
  19024. performed or not.
  19025. Defaults to @samp{disabled}.
  19026. @end deftypevr
  19027. @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
  19028. Set the name for the GSS-API Kerberos credentials cache.
  19029. Defaults to @samp{disabled}.
  19030. @end deftypevr
  19031. @deftypevr {@code{nslcd-configuration} parameter} string base
  19032. The directory search base.
  19033. Defaults to @samp{"dc=example,dc=com"}.
  19034. @end deftypevr
  19035. @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
  19036. Specifies the search scope (subtree, onelevel, base or children). The
  19037. default scope is subtree; base scope is almost never useful for name
  19038. service lookups; children scope is not supported on all servers.
  19039. Defaults to @samp{(subtree)}.
  19040. @end deftypevr
  19041. @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
  19042. Specifies the policy for dereferencing aliases. The default policy is
  19043. to never dereference aliases.
  19044. Defaults to @samp{disabled}.
  19045. @end deftypevr
  19046. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
  19047. Specifies whether automatic referral chasing should be enabled. The
  19048. default behaviour is to chase referrals.
  19049. Defaults to @samp{disabled}.
  19050. @end deftypevr
  19051. @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
  19052. This option allows for custom attributes to be looked up instead of the
  19053. default RFC 2307 attributes. It is a list of maps, each consisting of
  19054. the name of a map, the RFC 2307 attribute to match and the query
  19055. expression for the attribute as it is available in the directory.
  19056. Defaults to @samp{()}.
  19057. @end deftypevr
  19058. @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
  19059. A list of filters consisting of the name of a map to which the filter
  19060. applies and an LDAP search filter expression.
  19061. Defaults to @samp{()}.
  19062. @end deftypevr
  19063. @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
  19064. Specifies the time limit in seconds to use when connecting to the
  19065. directory server. The default value is 10 seconds.
  19066. Defaults to @samp{disabled}.
  19067. @end deftypevr
  19068. @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
  19069. Specifies the time limit (in seconds) to wait for a response from the
  19070. LDAP server. A value of zero, which is the default, is to wait
  19071. indefinitely for searches to be completed.
  19072. Defaults to @samp{disabled}.
  19073. @end deftypevr
  19074. @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
  19075. Specifies the period if inactivity (in seconds) after which the con‐
  19076. nection to the LDAP server will be closed. The default is not to time
  19077. out connections.
  19078. Defaults to @samp{disabled}.
  19079. @end deftypevr
  19080. @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
  19081. Specifies the number of seconds to sleep when connecting to all LDAP
  19082. servers fails. By default one second is waited between the first
  19083. failure and the first retry.
  19084. Defaults to @samp{disabled}.
  19085. @end deftypevr
  19086. @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
  19087. Specifies the time after which the LDAP server is considered to be
  19088. permanently unavailable. Once this time is reached retries will be done
  19089. only once per this time period. The default value is 10 seconds.
  19090. Defaults to @samp{disabled}.
  19091. @end deftypevr
  19092. @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
  19093. Specifies whether to use SSL/TLS or not (the default is not to). If
  19094. 'start-tls is specified then StartTLS is used rather than raw LDAP over
  19095. SSL.
  19096. Defaults to @samp{disabled}.
  19097. @end deftypevr
  19098. @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
  19099. Specifies what checks to perform on a server-supplied certificate. The
  19100. meaning of the values is described in the ldap.conf(5) manual page.
  19101. Defaults to @samp{disabled}.
  19102. @end deftypevr
  19103. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
  19104. Specifies the directory containing X.509 certificates for peer authen‐
  19105. tication. This parameter is ignored when using GnuTLS.
  19106. Defaults to @samp{disabled}.
  19107. @end deftypevr
  19108. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
  19109. Specifies the path to the X.509 certificate for peer authentication.
  19110. Defaults to @samp{disabled}.
  19111. @end deftypevr
  19112. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
  19113. Specifies the path to an entropy source. This parameter is ignored when
  19114. using GnuTLS.
  19115. Defaults to @samp{disabled}.
  19116. @end deftypevr
  19117. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
  19118. Specifies the ciphers to use for TLS as a string.
  19119. Defaults to @samp{disabled}.
  19120. @end deftypevr
  19121. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
  19122. Specifies the path to the file containing the local certificate for
  19123. client TLS authentication.
  19124. Defaults to @samp{disabled}.
  19125. @end deftypevr
  19126. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
  19127. Specifies the path to the file containing the private key for client TLS
  19128. authentication.
  19129. Defaults to @samp{disabled}.
  19130. @end deftypevr
  19131. @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
  19132. Set this to a number greater than 0 to request paged results from the
  19133. LDAP server in accordance with RFC2696. The default (0) is to not
  19134. request paged results.
  19135. Defaults to @samp{disabled}.
  19136. @end deftypevr
  19137. @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
  19138. This option prevents group membership lookups through LDAP for the
  19139. specified users. Alternatively, the value 'all-local may be used. With
  19140. that value nslcd builds a full list of non-LDAP users on startup.
  19141. Defaults to @samp{disabled}.
  19142. @end deftypevr
  19143. @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
  19144. This option ensures that LDAP users with a numeric user id lower than
  19145. the specified value are ignored.
  19146. Defaults to @samp{disabled}.
  19147. @end deftypevr
  19148. @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
  19149. This option specifies an offset that is added to all LDAP numeric user
  19150. ids. This can be used to avoid user id collisions with local users.
  19151. Defaults to @samp{disabled}.
  19152. @end deftypevr
  19153. @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
  19154. This option specifies an offset that is added to all LDAP numeric group
  19155. ids. This can be used to avoid user id collisions with local groups.
  19156. Defaults to @samp{disabled}.
  19157. @end deftypevr
  19158. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
  19159. If this option is set, the member attribute of a group may point to
  19160. another group. Members of nested groups are also returned in the higher
  19161. level group and parent groups are returned when finding groups for a
  19162. specific user. The default is not to perform extra searches for nested
  19163. groups.
  19164. Defaults to @samp{disabled}.
  19165. @end deftypevr
  19166. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
  19167. If this option is set, the group member list is not retrieved when
  19168. looking up groups. Lookups for finding which groups a user belongs to
  19169. will remain functional so the user will likely still get the correct
  19170. groups assigned on login.
  19171. Defaults to @samp{disabled}.
  19172. @end deftypevr
  19173. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
  19174. If this option is set, functions which cause all user/group entries to
  19175. be loaded from the directory will not succeed in doing so. This can
  19176. dramatically reduce LDAP server load in situations where there are a
  19177. great number of users and/or groups. This option is not recommended for
  19178. most configurations.
  19179. Defaults to @samp{disabled}.
  19180. @end deftypevr
  19181. @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
  19182. This option can be used to specify how user and group names are verified
  19183. within the system. This pattern is used to check all user and group
  19184. names that are requested and returned from LDAP.
  19185. Defaults to @samp{disabled}.
  19186. @end deftypevr
  19187. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
  19188. This specifies whether or not to perform searches using case-insensitive
  19189. matching. Enabling this could open up the system to authorization
  19190. bypass vulnerabilities and introduce nscd cache poisoning
  19191. vulnerabilities which allow denial of service.
  19192. Defaults to @samp{disabled}.
  19193. @end deftypevr
  19194. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
  19195. This option specifies whether password policy controls are requested and
  19196. handled from the LDAP server when performing user authentication.
  19197. Defaults to @samp{disabled}.
  19198. @end deftypevr
  19199. @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
  19200. By default nslcd performs an LDAP search with the user's credentials
  19201. after BIND (authentication) to ensure that the BIND operation was
  19202. successful. The default search is a simple check to see if the user's
  19203. DN exists. A search filter can be specified that will be used instead.
  19204. It should return at least one entry.
  19205. Defaults to @samp{disabled}.
  19206. @end deftypevr
  19207. @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
  19208. This option allows flexible fine tuning of the authorisation check that
  19209. should be performed. The search filter specified is executed and if any
  19210. entries match, access is granted, otherwise access is denied.
  19211. Defaults to @samp{disabled}.
  19212. @end deftypevr
  19213. @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
  19214. If this option is set password modification using pam_ldap will be
  19215. denied and the specified message will be presented to the user instead.
  19216. The message can be used to direct the user to an alternative means of
  19217. changing their password.
  19218. Defaults to @samp{disabled}.
  19219. @end deftypevr
  19220. @deftypevr {@code{nslcd-configuration} parameter} list pam-services
  19221. List of pam service names for which LDAP authentication should suffice.
  19222. Defaults to @samp{()}.
  19223. @end deftypevr
  19224. @c %end of generated documentation for nslcd-configuration
  19225. @node Web Services
  19226. @subsection Web Services
  19227. @cindex web
  19228. @cindex www
  19229. @cindex HTTP
  19230. The @code{(gnu services web)} module provides the Apache HTTP Server,
  19231. the nginx web server, and also a fastcgi wrapper daemon.
  19232. @subsubheading Apache HTTP Server
  19233. @deffn {Scheme Variable} httpd-service-type
  19234. Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
  19235. (@dfn{httpd}). The value for this service type is a
  19236. @code{httpd-configuration} record.
  19237. A simple example configuration is given below.
  19238. @lisp
  19239. (service httpd-service-type
  19240. (httpd-configuration
  19241. (config
  19242. (httpd-config-file
  19243. (server-name "www.example.com")
  19244. (document-root "/srv/http/www.example.com")))))
  19245. @end lisp
  19246. Other services can also extend the @code{httpd-service-type} to add to
  19247. the configuration.
  19248. @lisp
  19249. (simple-service 'www.example.com-server httpd-service-type
  19250. (list
  19251. (httpd-virtualhost
  19252. "*:80"
  19253. (list (string-join '("ServerName www.example.com"
  19254. "DocumentRoot /srv/http/www.example.com")
  19255. "\n")))))
  19256. @end lisp
  19257. @end deffn
  19258. The details for the @code{httpd-configuration}, @code{httpd-module},
  19259. @code{httpd-config-file} and @code{httpd-virtualhost} record types are
  19260. given below.
  19261. @deffn {Data Type} httpd-configuration
  19262. This data type represents the configuration for the httpd service.
  19263. @table @asis
  19264. @item @code{package} (default: @code{httpd})
  19265. The httpd package to use.
  19266. @item @code{pid-file} (default: @code{"/var/run/httpd"})
  19267. The pid file used by the shepherd-service.
  19268. @item @code{config} (default: @code{(httpd-config-file)})
  19269. The configuration file to use with the httpd service. The default value
  19270. is a @code{httpd-config-file} record, but this can also be a different
  19271. G-expression that generates a file, for example a @code{plain-file}. A
  19272. file outside of the store can also be specified through a string.
  19273. @end table
  19274. @end deffn
  19275. @deffn {Data Type} httpd-module
  19276. This data type represents a module for the httpd service.
  19277. @table @asis
  19278. @item @code{name}
  19279. The name of the module.
  19280. @item @code{file}
  19281. The file for the module. This can be relative to the httpd package being
  19282. used, the absolute location of a file, or a G-expression for a file
  19283. within the store, for example @code{(file-append mod-wsgi
  19284. "/modules/mod_wsgi.so")}.
  19285. @end table
  19286. @end deffn
  19287. @defvr {Scheme Variable} %default-httpd-modules
  19288. A default list of @code{httpd-module} objects.
  19289. @end defvr
  19290. @deffn {Data Type} httpd-config-file
  19291. This data type represents a configuration file for the httpd service.
  19292. @table @asis
  19293. @item @code{modules} (default: @code{%default-httpd-modules})
  19294. The modules to load. Additional modules can be added here, or loaded by
  19295. additional configuration.
  19296. For example, in order to handle requests for PHP files, you can use Apache’s
  19297. @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
  19298. @lisp
  19299. (service httpd-service-type
  19300. (httpd-configuration
  19301. (config
  19302. (httpd-config-file
  19303. (modules (cons*
  19304. (httpd-module
  19305. (name "proxy_module")
  19306. (file "modules/mod_proxy.so"))
  19307. (httpd-module
  19308. (name "proxy_fcgi_module")
  19309. (file "modules/mod_proxy_fcgi.so"))
  19310. %default-httpd-modules))
  19311. (extra-config (list "\
  19312. <FilesMatch \\.php$>
  19313. SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
  19314. </FilesMatch>"))))))
  19315. (service php-fpm-service-type
  19316. (php-fpm-configuration
  19317. (socket "/var/run/php-fpm.sock")
  19318. (socket-group "httpd")))
  19319. @end lisp
  19320. @item @code{server-root} (default: @code{httpd})
  19321. The @code{ServerRoot} in the configuration file, defaults to the httpd
  19322. package. Directives including @code{Include} and @code{LoadModule} are
  19323. taken as relative to the server root.
  19324. @item @code{server-name} (default: @code{#f})
  19325. The @code{ServerName} in the configuration file, used to specify the
  19326. request scheme, hostname and port that the server uses to identify
  19327. itself.
  19328. This doesn't need to be set in the server config, and can be specified
  19329. in virtual hosts. The default is @code{#f} to not specify a
  19330. @code{ServerName}.
  19331. @item @code{document-root} (default: @code{"/srv/http"})
  19332. The @code{DocumentRoot} from which files will be served.
  19333. @item @code{listen} (default: @code{'("80")})
  19334. The list of values for the @code{Listen} directives in the config
  19335. file. The value should be a list of strings, when each string can
  19336. specify the port number to listen on, and optionally the IP address and
  19337. protocol to use.
  19338. @item @code{pid-file} (default: @code{"/var/run/httpd"})
  19339. The @code{PidFile} to use. This should match the @code{pid-file} set in
  19340. the @code{httpd-configuration} so that the Shepherd service is
  19341. configured correctly.
  19342. @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
  19343. The @code{ErrorLog} to which the server will log errors.
  19344. @item @code{user} (default: @code{"httpd"})
  19345. The @code{User} which the server will answer requests as.
  19346. @item @code{group} (default: @code{"httpd"})
  19347. The @code{Group} which the server will answer requests as.
  19348. @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
  19349. A flat list of strings and G-expressions which will be added to the end
  19350. of the configuration file.
  19351. Any values which the service is extended with will be appended to this
  19352. list.
  19353. @end table
  19354. @end deffn
  19355. @deffn {Data Type} httpd-virtualhost
  19356. This data type represents a virtualhost configuration block for the httpd service.
  19357. These should be added to the extra-config for the httpd-service.
  19358. @lisp
  19359. (simple-service 'www.example.com-server httpd-service-type
  19360. (list
  19361. (httpd-virtualhost
  19362. "*:80"
  19363. (list (string-join '("ServerName www.example.com"
  19364. "DocumentRoot /srv/http/www.example.com")
  19365. "\n")))))
  19366. @end lisp
  19367. @table @asis
  19368. @item @code{addresses-and-ports}
  19369. The addresses and ports for the @code{VirtualHost} directive.
  19370. @item @code{contents}
  19371. The contents of the @code{VirtualHost} directive, this should be a list
  19372. of strings and G-expressions.
  19373. @end table
  19374. @end deffn
  19375. @subsubheading NGINX
  19376. @deffn {Scheme Variable} nginx-service-type
  19377. Service type for the @uref{https://nginx.org/,NGinx} web server. The
  19378. value for this service type is a @code{<nginx-configuration>} record.
  19379. A simple example configuration is given below.
  19380. @lisp
  19381. (service nginx-service-type
  19382. (nginx-configuration
  19383. (server-blocks
  19384. (list (nginx-server-configuration
  19385. (server-name '("www.example.com"))
  19386. (root "/srv/http/www.example.com"))))))
  19387. @end lisp
  19388. In addition to adding server blocks to the service configuration
  19389. directly, this service can be extended by other services to add server
  19390. blocks, as in this example:
  19391. @lisp
  19392. (simple-service 'my-extra-server nginx-service-type
  19393. (list (nginx-server-configuration
  19394. (root "/srv/http/extra-website")
  19395. (try-files (list "$uri" "$uri/index.html")))))
  19396. @end lisp
  19397. @end deffn
  19398. At startup, @command{nginx} has not yet read its configuration file, so
  19399. it uses a default file to log error messages. If it fails to load its
  19400. configuration file, that is where error messages are logged. After the
  19401. configuration file is loaded, the default error log file changes as per
  19402. configuration. In our case, startup error messages can be found in
  19403. @file{/var/run/nginx/logs/error.log}, and after configuration in
  19404. @file{/var/log/nginx/error.log}. The second location can be changed
  19405. with the @var{log-directory} configuration option.
  19406. @deffn {Data Type} nginx-configuration
  19407. This data type represents the configuration for NGinx. Some
  19408. configuration can be done through this and the other provided record
  19409. types, or alternatively, a config file can be provided.
  19410. @table @asis
  19411. @item @code{nginx} (default: @code{nginx})
  19412. The nginx package to use.
  19413. @item @code{log-directory} (default: @code{"/var/log/nginx"})
  19414. The directory to which NGinx will write log files.
  19415. @item @code{run-directory} (default: @code{"/var/run/nginx"})
  19416. The directory in which NGinx will create a pid file, and write temporary
  19417. files.
  19418. @item @code{server-blocks} (default: @code{'()})
  19419. A list of @dfn{server blocks} to create in the generated configuration
  19420. file, the elements should be of type
  19421. @code{<nginx-server-configuration>}.
  19422. The following example would setup NGinx to serve @code{www.example.com}
  19423. from the @code{/srv/http/www.example.com} directory, without using
  19424. HTTPS.
  19425. @lisp
  19426. (service nginx-service-type
  19427. (nginx-configuration
  19428. (server-blocks
  19429. (list (nginx-server-configuration
  19430. (server-name '("www.example.com"))
  19431. (root "/srv/http/www.example.com"))))))
  19432. @end lisp
  19433. @item @code{upstream-blocks} (default: @code{'()})
  19434. A list of @dfn{upstream blocks} to create in the generated configuration
  19435. file, the elements should be of type
  19436. @code{<nginx-upstream-configuration>}.
  19437. Configuring upstreams through the @code{upstream-blocks} can be useful
  19438. when combined with @code{locations} in the
  19439. @code{<nginx-server-configuration>} records. The following example
  19440. creates a server configuration with one location configuration, that
  19441. will proxy requests to a upstream configuration, which will handle
  19442. requests with two servers.
  19443. @lisp
  19444. (service
  19445. nginx-service-type
  19446. (nginx-configuration
  19447. (server-blocks
  19448. (list (nginx-server-configuration
  19449. (server-name '("www.example.com"))
  19450. (root "/srv/http/www.example.com")
  19451. (locations
  19452. (list
  19453. (nginx-location-configuration
  19454. (uri "/path1")
  19455. (body '("proxy_pass http://server-proxy;"))))))))
  19456. (upstream-blocks
  19457. (list (nginx-upstream-configuration
  19458. (name "server-proxy")
  19459. (servers (list "server1.example.com"
  19460. "server2.example.com")))))))
  19461. @end lisp
  19462. @item @code{file} (default: @code{#f})
  19463. If a configuration @var{file} is provided, this will be used, rather than
  19464. generating a configuration file from the provided @code{log-directory},
  19465. @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
  19466. proper operation, these arguments should match what is in @var{file} to ensure
  19467. that the directories are created when the service is activated.
  19468. This can be useful if you have an existing configuration file, or it's
  19469. not possible to do what is required through the other parts of the
  19470. nginx-configuration record.
  19471. @item @code{server-names-hash-bucket-size} (default: @code{#f})
  19472. Bucket size for the server names hash tables, defaults to @code{#f} to
  19473. use the size of the processors cache line.
  19474. @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
  19475. Maximum bucket size for the server names hash tables.
  19476. @item @code{modules} (default: @code{'()})
  19477. List of nginx dynamic modules to load. This should be a list of file
  19478. names of loadable modules, as in this example:
  19479. @lisp
  19480. (modules
  19481. (list
  19482. (file-append nginx-accept-language-module "\
  19483. /etc/nginx/modules/ngx_http_accept_language_module.so")
  19484. (file-append nginx-lua-module "\
  19485. /etc/nginx/modules/ngx_http_lua_module.so")))
  19486. @end lisp
  19487. @item @code{lua-package-path} (default: @code{'()})
  19488. List of nginx lua packages to load. This should be a list of package
  19489. names of loadable lua modules, as in this example:
  19490. @lisp
  19491. (lua-package-path (list lua-resty-core
  19492. lua-resty-lrucache
  19493. lua-resty-signal
  19494. lua-tablepool
  19495. lua-resty-shell))
  19496. @end lisp
  19497. @item @code{lua-package-cpath} (default: @code{'()})
  19498. List of nginx lua C packages to load. This should be a list of package
  19499. names of loadable lua C modules, as in this example:
  19500. @lisp
  19501. (lua-package-cpath (list lua-resty-signal))
  19502. @end lisp
  19503. @item @code{global-directives} (default: @code{'((events . ()))})
  19504. Association list of global directives for the top level of the nginx
  19505. configuration. Values may themselves be association lists.
  19506. @lisp
  19507. (global-directives
  19508. `((worker_processes . 16)
  19509. (pcre_jit . on)
  19510. (events . ((worker_connections . 1024)))))
  19511. @end lisp
  19512. @item @code{extra-content} (default: @code{""})
  19513. Extra content for the @code{http} block. Should be string or a string
  19514. valued G-expression.
  19515. @end table
  19516. @end deffn
  19517. @deftp {Data Type} nginx-server-configuration
  19518. Data type representing the configuration of an nginx server block.
  19519. This type has the following parameters:
  19520. @table @asis
  19521. @item @code{listen} (default: @code{'("80" "443 ssl")})
  19522. Each @code{listen} directive sets the address and port for IP, or the
  19523. path for a UNIX-domain socket on which the server will accept requests.
  19524. Both address and port, or only address or only port can be specified.
  19525. An address may also be a hostname, for example:
  19526. @lisp
  19527. '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
  19528. @end lisp
  19529. @item @code{server-name} (default: @code{(list 'default)})
  19530. A list of server names this server represents. @code{'default} represents the
  19531. default server for connections matching no other server.
  19532. @item @code{root} (default: @code{"/srv/http"})
  19533. Root of the website nginx will serve.
  19534. @item @code{locations} (default: @code{'()})
  19535. A list of @dfn{nginx-location-configuration} or
  19536. @dfn{nginx-named-location-configuration} records to use within this
  19537. server block.
  19538. @item @code{index} (default: @code{(list "index.html")})
  19539. Index files to look for when clients ask for a directory. If it cannot be found,
  19540. Nginx will send the list of files in the directory.
  19541. @item @code{try-files} (default: @code{'()})
  19542. A list of files whose existence is checked in the specified order.
  19543. @code{nginx} will use the first file it finds to process the request.
  19544. @item @code{ssl-certificate} (default: @code{#f})
  19545. Where to find the certificate for secure connections. Set it to @code{#f} if
  19546. you don't have a certificate or you don't want to use HTTPS.
  19547. @item @code{ssl-certificate-key} (default: @code{#f})
  19548. Where to find the private key for secure connections. Set it to @code{#f} if
  19549. you don't have a key or you don't want to use HTTPS.
  19550. @item @code{server-tokens?} (default: @code{#f})
  19551. Whether the server should add its configuration to response.
  19552. @item @code{raw-content} (default: @code{'()})
  19553. A list of raw lines added to the server block.
  19554. @end table
  19555. @end deftp
  19556. @deftp {Data Type} nginx-upstream-configuration
  19557. Data type representing the configuration of an nginx @code{upstream}
  19558. block. This type has the following parameters:
  19559. @table @asis
  19560. @item @code{name}
  19561. Name for this group of servers.
  19562. @item @code{servers}
  19563. Specify the addresses of the servers in the group. The address can be
  19564. specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
  19565. (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
  19566. prefix @samp{unix:}. For addresses using an IP address or domain name,
  19567. the default port is 80, and a different port can be specified
  19568. explicitly.
  19569. @end table
  19570. @end deftp
  19571. @deftp {Data Type} nginx-location-configuration
  19572. Data type representing the configuration of an nginx @code{location}
  19573. block. This type has the following parameters:
  19574. @table @asis
  19575. @item @code{uri}
  19576. URI which this location block matches.
  19577. @anchor{nginx-location-configuration body}
  19578. @item @code{body}
  19579. Body of the location block, specified as a list of strings. This can contain
  19580. many
  19581. configuration directives. For example, to pass requests to a upstream
  19582. server group defined using an @code{nginx-upstream-configuration} block,
  19583. the following directive would be specified in the body @samp{(list "proxy_pass
  19584. http://upstream-name;")}.
  19585. @end table
  19586. @end deftp
  19587. @deftp {Data Type} nginx-named-location-configuration
  19588. Data type representing the configuration of an nginx named location
  19589. block. Named location blocks are used for request redirection, and not
  19590. used for regular request processing. This type has the following
  19591. parameters:
  19592. @table @asis
  19593. @item @code{name}
  19594. Name to identify this location block.
  19595. @item @code{body}
  19596. @xref{nginx-location-configuration body}, as the body for named location
  19597. blocks can be used in a similar way to the
  19598. @code{nginx-location-configuration body}. One restriction is that the
  19599. body of a named location block cannot contain location blocks.
  19600. @end table
  19601. @end deftp
  19602. @subsubheading Varnish Cache
  19603. @cindex Varnish
  19604. Varnish is a fast cache server that sits in between web applications
  19605. and end users. It proxies requests from clients and caches the
  19606. accessed URLs such that multiple requests for the same resource only
  19607. creates one request to the back-end.
  19608. @defvr {Scheme Variable} varnish-service-type
  19609. Service type for the Varnish daemon.
  19610. @end defvr
  19611. @deftp {Data Type} varnish-configuration
  19612. Data type representing the @code{varnish} service configuration.
  19613. This type has the following parameters:
  19614. @table @asis
  19615. @item @code{package} (default: @code{varnish})
  19616. The Varnish package to use.
  19617. @item @code{name} (default: @code{"default"})
  19618. A name for this Varnish instance. Varnish will create a directory in
  19619. @file{/var/varnish/} with this name and keep temporary files there. If
  19620. the name starts with a forward slash, it is interpreted as an absolute
  19621. directory name.
  19622. Pass the @code{-n} argument to other Varnish programs to connect to the
  19623. named instance, e.g.@: @command{varnishncsa -n default}.
  19624. @item @code{backend} (default: @code{"localhost:8080"})
  19625. The backend to use. This option has no effect if @code{vcl} is set.
  19626. @item @code{vcl} (default: #f)
  19627. The @dfn{VCL} (Varnish Configuration Language) program to run. If this
  19628. is @code{#f}, Varnish will proxy @code{backend} using the default
  19629. configuration. Otherwise this must be a file-like object with valid
  19630. VCL syntax.
  19631. @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
  19632. For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
  19633. can do something along these lines:
  19634. @lisp
  19635. (define %gnu-mirror
  19636. (plain-file "gnu.vcl"
  19637. "vcl 4.1;
  19638. backend gnu @{ .host = \"www.gnu.org\"; @}"))
  19639. (operating-system
  19640. ;; @dots{}
  19641. (services (cons (service varnish-service-type
  19642. (varnish-configuration
  19643. (listen '(":80"))
  19644. (vcl %gnu-mirror)))
  19645. %base-services)))
  19646. @end lisp
  19647. The configuration of an already running Varnish instance can be inspected
  19648. and changed using the @command{varnishadm} program.
  19649. Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
  19650. @url{https://book.varnish-software.com/4.0/,Varnish Book} for
  19651. comprehensive documentation on Varnish and its configuration language.
  19652. @item @code{listen} (default: @code{'("localhost:80")})
  19653. List of addresses Varnish will listen on.
  19654. @item @code{storage} (default: @code{'("malloc,128m")})
  19655. List of storage backends that will be available in VCL.
  19656. @item @code{parameters} (default: @code{'()})
  19657. List of run-time parameters in the form @code{'(("parameter" . "value"))}.
  19658. @item @code{extra-options} (default: @code{'()})
  19659. Additional arguments to pass to the @command{varnishd} process.
  19660. @end table
  19661. @end deftp
  19662. @subsubheading Patchwork
  19663. @cindex Patchwork
  19664. Patchwork is a patch tracking system. It can collect patches sent to a
  19665. mailing list, and display them in a web interface.
  19666. @defvr {Scheme Variable} patchwork-service-type
  19667. Service type for Patchwork.
  19668. @end defvr
  19669. The following example is an example of a minimal service for Patchwork, for
  19670. the @code{patchwork.example.com} domain.
  19671. @lisp
  19672. (service patchwork-service-type
  19673. (patchwork-configuration
  19674. (domain "patchwork.example.com")
  19675. (settings-module
  19676. (patchwork-settings-module
  19677. (allowed-hosts (list domain))
  19678. (default-from-email "patchwork@@patchwork.example.com")))
  19679. (getmail-retriever-config
  19680. (getmail-retriever-configuration
  19681. (type "SimpleIMAPSSLRetriever")
  19682. (server "imap.example.com")
  19683. (port 993)
  19684. (username "patchwork")
  19685. (password-command
  19686. (list (file-append coreutils "/bin/cat")
  19687. "/etc/getmail-patchwork-imap-password"))
  19688. (extra-parameters
  19689. '((mailboxes . ("Patches"))))))))
  19690. @end lisp
  19691. There are three records for configuring the Patchwork service. The
  19692. @code{<patchwork-configuration>} relates to the configuration for Patchwork
  19693. within the HTTPD service.
  19694. The @code{settings-module} field within the @code{<patchwork-configuration>}
  19695. record can be populated with the @code{<patchwork-settings-module>} record,
  19696. which describes a settings module that is generated within the Guix store.
  19697. For the @code{database-configuration} field within the
  19698. @code{<patchwork-settings-module>}, the
  19699. @code{<patchwork-database-configuration>} must be used.
  19700. @deftp {Data Type} patchwork-configuration
  19701. Data type representing the Patchwork service configuration. This type has the
  19702. following parameters:
  19703. @table @asis
  19704. @item @code{patchwork} (default: @code{patchwork})
  19705. The Patchwork package to use.
  19706. @item @code{domain}
  19707. The domain to use for Patchwork, this is used in the HTTPD service virtual
  19708. host.
  19709. @item @code{settings-module}
  19710. The settings module to use for Patchwork. As a Django application, Patchwork
  19711. is configured with a Python module containing the settings. This can either be
  19712. an instance of the @code{<patchwork-settings-module>} record, any other record
  19713. that represents the settings in the store, or a directory outside of the
  19714. store.
  19715. @item @code{static-path} (default: @code{"/static/"})
  19716. The path under which the HTTPD service should serve the static files.
  19717. @item @code{getmail-retriever-config}
  19718. The getmail-retriever-configuration record value to use with
  19719. Patchwork. Getmail will be configured with this value, the messages will be
  19720. delivered to Patchwork.
  19721. @end table
  19722. @end deftp
  19723. @deftp {Data Type} patchwork-settings-module
  19724. Data type representing a settings module for Patchwork. Some of these
  19725. settings relate directly to Patchwork, but others relate to Django, the web
  19726. framework used by Patchwork, or the Django Rest Framework library. This type
  19727. has the following parameters:
  19728. @table @asis
  19729. @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
  19730. The database connection settings used for Patchwork. See the
  19731. @code{<patchwork-database-configuration>} record type for more information.
  19732. @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
  19733. Patchwork, as a Django web application uses a secret key for cryptographically
  19734. signing values. This file should contain a unique unpredictable value.
  19735. If this file does not exist, it will be created and populated with a random
  19736. value by the patchwork-setup shepherd service.
  19737. This setting relates to Django.
  19738. @item @code{allowed-hosts}
  19739. A list of valid hosts for this Patchwork service. This should at least include
  19740. the domain specified in the @code{<patchwork-configuration>} record.
  19741. This is a Django setting.
  19742. @item @code{default-from-email}
  19743. The email address from which Patchwork should send email by default.
  19744. This is a Patchwork setting.
  19745. @item @code{static-url} (default: @code{#f})
  19746. The URL to use when serving static assets. It can be part of a URL, or a full
  19747. URL, but must end in a @code{/}.
  19748. If the default value is used, the @code{static-path} value from the
  19749. @code{<patchwork-configuration>} record will be used.
  19750. This is a Django setting.
  19751. @item @code{admins} (default: @code{'()})
  19752. Email addresses to send the details of errors that occur. Each value should
  19753. be a list containing two elements, the name and then the email address.
  19754. This is a Django setting.
  19755. @item @code{debug?} (default: @code{#f})
  19756. Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
  19757. messages will be shown.
  19758. This is a Django setting.
  19759. @item @code{enable-rest-api?} (default: @code{#t})
  19760. Whether to enable the Patchwork REST API.
  19761. This is a Patchwork setting.
  19762. @item @code{enable-xmlrpc?} (default: @code{#t})
  19763. Whether to enable the XML RPC API.
  19764. This is a Patchwork setting.
  19765. @item @code{force-https-links?} (default: @code{#t})
  19766. Whether to use HTTPS links on Patchwork pages.
  19767. This is a Patchwork setting.
  19768. @item @code{extra-settings} (default: @code{""})
  19769. Extra code to place at the end of the Patchwork settings module.
  19770. @end table
  19771. @end deftp
  19772. @deftp {Data Type} patchwork-database-configuration
  19773. Data type representing the database configuration for Patchwork.
  19774. @table @asis
  19775. @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
  19776. The database engine to use.
  19777. @item @code{name} (default: @code{"patchwork"})
  19778. The name of the database to use.
  19779. @item @code{user} (default: @code{"httpd"})
  19780. The user to connect to the database as.
  19781. @item @code{password} (default: @code{""})
  19782. The password to use when connecting to the database.
  19783. @item @code{host} (default: @code{""})
  19784. The host to make the database connection to.
  19785. @item @code{port} (default: @code{""})
  19786. The port on which to connect to the database.
  19787. @end table
  19788. @end deftp
  19789. @subsubheading Mumi
  19790. @cindex Mumi, Debbugs Web interface
  19791. @cindex Debbugs, Mumi Web interface
  19792. @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
  19793. Web interface to the Debbugs bug tracker, by default for
  19794. @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
  19795. but it also fetches and indexes mail retrieved from Debbugs.
  19796. @defvr {Scheme Variable} mumi-service-type
  19797. This is the service type for Mumi.
  19798. @end defvr
  19799. @deftp {Data Type} mumi-configuration
  19800. Data type representing the Mumi service configuration. This type has the
  19801. following fields:
  19802. @table @asis
  19803. @item @code{mumi} (default: @code{mumi})
  19804. The Mumi package to use.
  19805. @item @code{mailer?} (default: @code{#true})
  19806. Whether to enable or disable the mailer component.
  19807. @item @code{mumi-configuration-sender}
  19808. The email address used as the sender for comments.
  19809. @item @code{mumi-configuration-smtp}
  19810. A URI to configure the SMTP settings for Mailutils. This could be
  19811. something like @code{sendmail:///path/to/bin/msmtp} or any other URI
  19812. supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
  19813. mailutils, GNU@tie{}Mailutils}.
  19814. @end table
  19815. @end deftp
  19816. @subsubheading FastCGI
  19817. @cindex fastcgi
  19818. @cindex fcgiwrap
  19819. FastCGI is an interface between the front-end and the back-end of a web
  19820. service. It is a somewhat legacy facility; new web services should
  19821. generally just talk HTTP between the front-end and the back-end.
  19822. However there are a number of back-end services such as PHP or the
  19823. optimized HTTP Git repository access that use FastCGI, so we have
  19824. support for it in Guix.
  19825. To use FastCGI, you configure the front-end web server (e.g., nginx) to
  19826. dispatch some subset of its requests to the fastcgi backend, which
  19827. listens on a local TCP or UNIX socket. There is an intermediary
  19828. @code{fcgiwrap} program that sits between the actual backend process and
  19829. the web server. The front-end indicates which backend program to run,
  19830. passing that information to the @code{fcgiwrap} process.
  19831. @defvr {Scheme Variable} fcgiwrap-service-type
  19832. A service type for the @code{fcgiwrap} FastCGI proxy.
  19833. @end defvr
  19834. @deftp {Data Type} fcgiwrap-configuration
  19835. Data type representing the configuration of the @code{fcgiwrap} service.
  19836. This type has the following parameters:
  19837. @table @asis
  19838. @item @code{package} (default: @code{fcgiwrap})
  19839. The fcgiwrap package to use.
  19840. @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
  19841. The socket on which the @code{fcgiwrap} process should listen, as a
  19842. string. Valid @var{socket} values include
  19843. @code{unix:@var{/path/to/unix/socket}},
  19844. @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
  19845. @code{tcp6:[@var{ipv6_addr}]:port}.
  19846. @item @code{user} (default: @code{fcgiwrap})
  19847. @itemx @code{group} (default: @code{fcgiwrap})
  19848. The user and group names, as strings, under which to run the
  19849. @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
  19850. the user asks for the specific user or group names @code{fcgiwrap} that
  19851. the corresponding user and/or group is present on the system.
  19852. It is possible to configure a FastCGI-backed web service to pass HTTP
  19853. authentication information from the front-end to the back-end, and to
  19854. allow @code{fcgiwrap} to run the back-end process as a corresponding
  19855. local user. To enable this capability on the back-end, run
  19856. @code{fcgiwrap} as the @code{root} user and group. Note that this
  19857. capability also has to be configured on the front-end as well.
  19858. @end table
  19859. @end deftp
  19860. @cindex php-fpm
  19861. PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
  19862. with some additional features useful for sites of any size.
  19863. These features include:
  19864. @itemize @bullet
  19865. @item Adaptive process spawning
  19866. @item Basic statistics (similar to Apache's mod_status)
  19867. @item Advanced process management with graceful stop/start
  19868. @item Ability to start workers with different uid/gid/chroot/environment
  19869. and different php.ini (replaces safe_mode)
  19870. @item Stdout & stderr logging
  19871. @item Emergency restart in case of accidental opcode cache destruction
  19872. @item Accelerated upload support
  19873. @item Support for a "slowlog"
  19874. @item Enhancements to FastCGI, such as fastcgi_finish_request() -
  19875. a special function to finish request & flush all data while continuing to do
  19876. something time-consuming (video converting, stats processing, etc.)
  19877. @end itemize
  19878. ...@: and much more.
  19879. @defvr {Scheme Variable} php-fpm-service-type
  19880. A Service type for @code{php-fpm}.
  19881. @end defvr
  19882. @deftp {Data Type} php-fpm-configuration
  19883. Data Type for php-fpm service configuration.
  19884. @table @asis
  19885. @item @code{php} (default: @code{php})
  19886. The php package to use.
  19887. @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
  19888. The address on which to accept FastCGI requests. Valid syntaxes are:
  19889. @table @asis
  19890. @item @code{"ip.add.re.ss:port"}
  19891. Listen on a TCP socket to a specific address on a specific port.
  19892. @item @code{"port"}
  19893. Listen on a TCP socket to all addresses on a specific port.
  19894. @item @code{"/path/to/unix/socket"}
  19895. Listen on a unix socket.
  19896. @end table
  19897. @item @code{user} (default: @code{php-fpm})
  19898. User who will own the php worker processes.
  19899. @item @code{group} (default: @code{php-fpm})
  19900. Group of the worker processes.
  19901. @item @code{socket-user} (default: @code{php-fpm})
  19902. User who can speak to the php-fpm socket.
  19903. @item @code{socket-group} (default: @code{nginx})
  19904. Group that can speak to the php-fpm socket.
  19905. @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
  19906. The process id of the php-fpm process is written to this file
  19907. once the service has started.
  19908. @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
  19909. Log for the php-fpm master process.
  19910. @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
  19911. Detailed settings for the php-fpm process manager.
  19912. Must be one of:
  19913. @table @asis
  19914. @item @code{<php-fpm-dynamic-process-manager-configuration>}
  19915. @item @code{<php-fpm-static-process-manager-configuration>}
  19916. @item @code{<php-fpm-on-demand-process-manager-configuration>}
  19917. @end table
  19918. @item @code{display-errors} (default @code{#f})
  19919. Determines whether php errors and warning should be sent to clients
  19920. and displayed in their browsers.
  19921. This is useful for local php development, but a security risk for public sites,
  19922. as error messages can reveal passwords and personal data.
  19923. @item @code{timezone} (default @code{#f})
  19924. Specifies @code{php_admin_value[date.timezone]} parameter.
  19925. @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
  19926. This file will log the @code{stderr} outputs of php worker processes.
  19927. Can be set to @code{#f} to disable logging.
  19928. @item @code{file} (default @code{#f})
  19929. An optional override of the whole configuration.
  19930. You can use the @code{mixed-text-file} function or an absolute filepath for it.
  19931. @item @code{php-ini-file} (default @code{#f})
  19932. An optional override of the default php settings.
  19933. It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
  19934. You can use the @code{mixed-text-file} function or an absolute filepath for it.
  19935. For local development it is useful to set a higher timeout and memory
  19936. limit for spawned php processes. This be accomplished with the
  19937. following operating system configuration snippet:
  19938. @lisp
  19939. (define %local-php-ini
  19940. (plain-file "php.ini"
  19941. "memory_limit = 2G
  19942. max_execution_time = 1800"))
  19943. (operating-system
  19944. ;; @dots{}
  19945. (services (cons (service php-fpm-service-type
  19946. (php-fpm-configuration
  19947. (php-ini-file %local-php-ini)))
  19948. %base-services)))
  19949. @end lisp
  19950. Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
  19951. directives} for comprehensive documentation on the acceptable
  19952. @file{php.ini} directives.
  19953. @end table
  19954. @end deftp
  19955. @deftp {Data type} php-fpm-dynamic-process-manager-configuration
  19956. Data Type for the @code{dynamic} php-fpm process manager. With the
  19957. @code{dynamic} process manager, spare worker processes are kept around
  19958. based on it's configured limits.
  19959. @table @asis
  19960. @item @code{max-children} (default: @code{5})
  19961. Maximum of worker processes.
  19962. @item @code{start-servers} (default: @code{2})
  19963. How many worker processes should be started on start-up.
  19964. @item @code{min-spare-servers} (default: @code{1})
  19965. How many spare worker processes should be kept around at minimum.
  19966. @item @code{max-spare-servers} (default: @code{3})
  19967. How many spare worker processes should be kept around at maximum.
  19968. @end table
  19969. @end deftp
  19970. @deftp {Data type} php-fpm-static-process-manager-configuration
  19971. Data Type for the @code{static} php-fpm process manager. With the
  19972. @code{static} process manager, an unchanging number of worker processes
  19973. are created.
  19974. @table @asis
  19975. @item @code{max-children} (default: @code{5})
  19976. Maximum of worker processes.
  19977. @end table
  19978. @end deftp
  19979. @deftp {Data type} php-fpm-on-demand-process-manager-configuration
  19980. Data Type for the @code{on-demand} php-fpm process manager. With the
  19981. @code{on-demand} process manager, worker processes are only created as
  19982. requests arrive.
  19983. @table @asis
  19984. @item @code{max-children} (default: @code{5})
  19985. Maximum of worker processes.
  19986. @item @code{process-idle-timeout} (default: @code{10})
  19987. The time in seconds after which a process with no requests is killed.
  19988. @end table
  19989. @end deftp
  19990. @deffn {Scheme Procedure} nginx-php-location @
  19991. [#:nginx-package nginx] @
  19992. [socket (string-append "/var/run/php" @
  19993. (version-major (package-version php)) @
  19994. "-fpm.sock")]
  19995. A helper function to quickly add php to an @code{nginx-server-configuration}.
  19996. @end deffn
  19997. A simple services setup for nginx with php can look like this:
  19998. @lisp
  19999. (services (cons* (service dhcp-client-service-type)
  20000. (service php-fpm-service-type)
  20001. (service nginx-service-type
  20002. (nginx-server-configuration
  20003. (server-name '("example.com"))
  20004. (root "/srv/http/")
  20005. (locations
  20006. (list (nginx-php-location)))
  20007. (listen '("80"))
  20008. (ssl-certificate #f)
  20009. (ssl-certificate-key #f)))
  20010. %base-services))
  20011. @end lisp
  20012. @cindex cat-avatar-generator
  20013. The cat avatar generator is a simple service to demonstrate the use of php-fpm
  20014. in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
  20015. the hash of a user's email address.
  20016. @deffn {Scheme Procedure} cat-avatar-generator-service @
  20017. [#:cache-dir "/var/cache/cat-avatar-generator"] @
  20018. [#:package cat-avatar-generator] @
  20019. [#:configuration (nginx-server-configuration)]
  20020. Returns an nginx-server-configuration that inherits @code{configuration}. It
  20021. extends the nginx configuration to add a server block that serves @code{package},
  20022. a version of cat-avatar-generator. During execution, cat-avatar-generator will
  20023. be able to use @code{cache-dir} as its cache directory.
  20024. @end deffn
  20025. A simple setup for cat-avatar-generator can look like this:
  20026. @lisp
  20027. (services (cons* (cat-avatar-generator-service
  20028. #:configuration
  20029. (nginx-server-configuration
  20030. (server-name '("example.com"))))
  20031. ...
  20032. %base-services))
  20033. @end lisp
  20034. @subsubheading Hpcguix-web
  20035. @cindex hpcguix-web
  20036. The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
  20037. program is a customizable web interface to browse Guix packages,
  20038. initially designed for users of high-performance computing (HPC)
  20039. clusters.
  20040. @defvr {Scheme Variable} hpcguix-web-service-type
  20041. The service type for @code{hpcguix-web}.
  20042. @end defvr
  20043. @deftp {Data Type} hpcguix-web-configuration
  20044. Data type for the hpcguix-web service configuration.
  20045. @table @asis
  20046. @item @code{specs}
  20047. A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
  20048. configuration. The main items available in this spec are:
  20049. @table @asis
  20050. @item @code{title-prefix} (default: @code{"hpcguix | "})
  20051. The page title prefix.
  20052. @item @code{guix-command} (default: @code{"guix"})
  20053. The @command{guix} command.
  20054. @item @code{package-filter-proc} (default: @code{(const #t)})
  20055. A procedure specifying how to filter packages that are displayed.
  20056. @item @code{package-page-extension-proc} (default: @code{(const '())})
  20057. Extension package for @code{hpcguix-web}.
  20058. @item @code{menu} (default: @code{'()})
  20059. Additional entry in page @code{menu}.
  20060. @item @code{channels} (default: @code{%default-channels})
  20061. List of channels from which the package list is built (@pxref{Channels}).
  20062. @item @code{package-list-expiration} (default: @code{(* 12 3600)})
  20063. The expiration time, in seconds, after which the package list is rebuilt from
  20064. the latest instances of the given channels.
  20065. @end table
  20066. See the hpcguix-web repository for a
  20067. @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
  20068. complete example}.
  20069. @item @code{package} (default: @code{hpcguix-web})
  20070. The hpcguix-web package to use.
  20071. @end table
  20072. @end deftp
  20073. A typical hpcguix-web service declaration looks like this:
  20074. @lisp
  20075. (service hpcguix-web-service-type
  20076. (hpcguix-web-configuration
  20077. (specs
  20078. #~(define site-config
  20079. (hpcweb-configuration
  20080. (title-prefix "Guix-HPC - ")
  20081. (menu '(("/about" "ABOUT"))))))))
  20082. @end lisp
  20083. @quotation Note
  20084. The hpcguix-web service periodically updates the package list it publishes by
  20085. pulling channels from Git. To that end, it needs to access X.509 certificates
  20086. so that it can authenticate Git servers when communicating over HTTPS, and it
  20087. assumes that @file{/etc/ssl/certs} contains those certificates.
  20088. Thus, make sure to add @code{nss-certs} or another certificate package to the
  20089. @code{packages} field of your configuration. @ref{X.509 Certificates}, for
  20090. more information on X.509 certificates.
  20091. @end quotation
  20092. @subsubheading gmnisrv
  20093. @cindex gmnisrv
  20094. The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
  20095. simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
  20096. @deffn {Scheme Variable} gmnisrv-service-type
  20097. This is the type of the gmnisrv service, whose value should be a
  20098. @code{gmnisrv-configuration} object, as in this example:
  20099. @lisp
  20100. (service gmnisrv-service-type
  20101. (gmnisrv-configuration
  20102. (config-file (local-file "./my-gmnisrv.ini"))))
  20103. @end lisp
  20104. @end deffn
  20105. @deftp {Data Type} gmnisrv-configuration
  20106. Data type representing the configuration of gmnisrv.
  20107. @table @asis
  20108. @item @code{package} (default: @var{gmnisrv})
  20109. Package object of the gmnisrv server.
  20110. @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
  20111. File-like object of the gmnisrv configuration file to use. The default
  20112. configuration listens on port 1965 and serves files from
  20113. @file{/srv/gemini}. Certificates are stored in
  20114. @file{/var/lib/gemini/certs}. For more information, run @command{man
  20115. gmnisrv} and @command{man gmnisrv.ini}.
  20116. @end table
  20117. @end deftp
  20118. @subsubheading Agate
  20119. @cindex agate
  20120. The @uref{gemini://qwertqwefsday.eu/agate.gmi, Agate}
  20121. (@uref{https://github.com/mbrubeck/agate, GitHub page over HTTPS})
  20122. program is a simple @uref{https://gemini.circumlunar.space/, Gemini}
  20123. protocol server written in Rust.
  20124. @deffn {Scheme Variable} agate-service-type
  20125. This is the type of the agate service, whose value should be an
  20126. @code{agate-service-type} object, as in this example:
  20127. @lisp
  20128. (service agate-service-type
  20129. (agate-configuration
  20130. (content "/srv/gemini")
  20131. (cert "/srv/cert.pem")
  20132. (key "/srv/key.rsa")))
  20133. @end lisp
  20134. The example above represents the minimal tweaking necessary to get Agate
  20135. up and running. Specifying the path to the certificate and key is
  20136. always necessary, as the Gemini protocol requires TLS by default.
  20137. To obtain a certificate and a key, you could, for example, use OpenSSL,
  20138. running a command similar to the following example:
  20139. @example
  20140. openssl req -x509 -newkey rsa:4096 -keyout key.rsa -out cert.pem \
  20141. -days 3650 -nodes -subj "/CN=example.com"
  20142. @end example
  20143. Of course, you'll have to replace @i{example.com} with your own domain
  20144. name, and then point the Agate configuration towards the path of the
  20145. generated key and certificate.
  20146. @end deffn
  20147. @deftp {Data Type} agate-configuration
  20148. Data type representing the configuration of Agate.
  20149. @table @asis
  20150. @item @code{package} (default: @code{agate})
  20151. The package object of the Agate server.
  20152. @item @code{content} (default: @file{"/srv/gemini"})
  20153. The directory from which Agate will serve files.
  20154. @item @code{cert} (default: @code{#f})
  20155. The path to the TLS certificate PEM file to be used for encrypted
  20156. connections. Must be filled in with a value from the user.
  20157. @item @code{key} (default: @code{#f})
  20158. The path to the PKCS8 private key file to be used for encrypted
  20159. connections. Must be filled in with a value from the user.
  20160. @item @code{addr} (default: @code{'("0.0.0.0:1965" "[::]:1965")})
  20161. A list of the addresses to listen on.
  20162. @item @code{hostname} (default: @code{#f})
  20163. The domain name of this Gemini server. Optional.
  20164. @item @code{lang} (default: @code{#f})
  20165. RFC 4646 language code(s) for text/gemini documents. Optional.
  20166. @item @code{silent?} (default: @code{#f})
  20167. Set to @code{#t} to disable logging output.
  20168. @item @code{serve-secret?} (default: @code{#f})
  20169. Set to @code{#t} to serve secret files (files/directories starting with
  20170. a dot).
  20171. @item @code{log-ip?} (default: @code{#t})
  20172. Whether or not to output IP addresses when logging.
  20173. @item @code{user} (default: @code{"agate"})
  20174. Owner of the @code{agate} process.
  20175. @item @code{group} (default: @code{"agate"})
  20176. Owner's group of the @code{agate} process.
  20177. @item @code{log-file} (default: @file{"/var/log/agate.log"})
  20178. The file which should store the logging output of Agate.
  20179. @end table
  20180. @end deftp
  20181. @node Certificate Services
  20182. @subsection Certificate Services
  20183. @cindex Web
  20184. @cindex HTTP, HTTPS
  20185. @cindex Let's Encrypt
  20186. @cindex TLS certificates
  20187. The @code{(gnu services certbot)} module provides a service to
  20188. automatically obtain a valid TLS certificate from the Let's Encrypt
  20189. certificate authority. These certificates can then be used to serve
  20190. content securely over HTTPS or other TLS-based protocols, with the
  20191. knowledge that the client will be able to verify the server's
  20192. authenticity.
  20193. @url{https://letsencrypt.org/, Let's Encrypt} provides the
  20194. @code{certbot} tool to automate the certification process. This tool
  20195. first securely generates a key on the server. It then makes a request
  20196. to the Let's Encrypt certificate authority (CA) to sign the key. The CA
  20197. checks that the request originates from the host in question by using a
  20198. challenge-response protocol, requiring the server to provide its
  20199. response over HTTP@. If that protocol completes successfully, the CA
  20200. signs the key, resulting in a certificate. That certificate is valid
  20201. for a limited period of time, and therefore to continue to provide TLS
  20202. services, the server needs to periodically ask the CA to renew its
  20203. signature.
  20204. The certbot service automates this process: the initial key
  20205. generation, the initial certification request to the Let's Encrypt
  20206. service, the web server challenge/response integration, writing the
  20207. certificate to disk, the automated periodic renewals, and the deployment
  20208. tasks associated with the renewal (e.g.@: reloading services, copying keys
  20209. with different permissions).
  20210. Certbot is run twice a day, at a random minute within the hour. It
  20211. won't do anything until your certificates are due for renewal or
  20212. revoked, but running it regularly would give your service a chance of
  20213. staying online in case a Let's Encrypt-initiated revocation happened for
  20214. some reason.
  20215. By using this service, you agree to the ACME Subscriber Agreement, which
  20216. can be found there:
  20217. @url{https://acme-v01.api.letsencrypt.org/directory}.
  20218. @defvr {Scheme Variable} certbot-service-type
  20219. A service type for the @code{certbot} Let's Encrypt client. Its value
  20220. must be a @code{certbot-configuration} record as in this example:
  20221. @lisp
  20222. (define %nginx-deploy-hook
  20223. (program-file
  20224. "nginx-deploy-hook"
  20225. #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
  20226. (kill pid SIGHUP))))
  20227. (service certbot-service-type
  20228. (certbot-configuration
  20229. (email "foo@@example.net")
  20230. (certificates
  20231. (list
  20232. (certificate-configuration
  20233. (domains '("example.net" "www.example.net"))
  20234. (deploy-hook %nginx-deploy-hook))
  20235. (certificate-configuration
  20236. (domains '("bar.example.net")))))))
  20237. @end lisp
  20238. See below for details about @code{certbot-configuration}.
  20239. @end defvr
  20240. @deftp {Data Type} certbot-configuration
  20241. Data type representing the configuration of the @code{certbot} service.
  20242. This type has the following parameters:
  20243. @table @asis
  20244. @item @code{package} (default: @code{certbot})
  20245. The certbot package to use.
  20246. @item @code{webroot} (default: @code{/var/www})
  20247. The directory from which to serve the Let's Encrypt challenge/response
  20248. files.
  20249. @item @code{certificates} (default: @code{()})
  20250. A list of @code{certificates-configuration}s for which to generate
  20251. certificates and request signatures. Each certificate has a @code{name}
  20252. and several @code{domains}.
  20253. @item @code{email} (default: @code{#f})
  20254. Optional email address used for registration and recovery contact.
  20255. Setting this is encouraged as it allows you to receive important
  20256. notifications about the account and issued certificates.
  20257. @item @code{server} (default: @code{#f})
  20258. Optional URL of ACME server. Setting this overrides certbot's default,
  20259. which is the Let's Encrypt server.
  20260. @item @code{rsa-key-size} (default: @code{2048})
  20261. Size of the RSA key.
  20262. @item @code{default-location} (default: @i{see below})
  20263. The default @code{nginx-location-configuration}. Because @code{certbot}
  20264. needs to be able to serve challenges and responses, it needs to be able
  20265. to run a web server. It does so by extending the @code{nginx} web
  20266. service with an @code{nginx-server-configuration} listening on the
  20267. @var{domains} on port 80, and which has a
  20268. @code{nginx-location-configuration} for the @code{/.well-known/} URI
  20269. path subspace used by Let's Encrypt. @xref{Web Services}, for more on
  20270. these nginx configuration data types.
  20271. Requests to other URL paths will be matched by the
  20272. @code{default-location}, which if present is added to all
  20273. @code{nginx-server-configuration}s.
  20274. By default, the @code{default-location} will issue a redirect from
  20275. @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
  20276. you to define what to serve on your site via @code{https}.
  20277. Pass @code{#f} to not issue a default location.
  20278. @end table
  20279. @end deftp
  20280. @deftp {Data Type} certificate-configuration
  20281. Data type representing the configuration of a certificate.
  20282. This type has the following parameters:
  20283. @table @asis
  20284. @item @code{name} (default: @i{see below})
  20285. This name is used by Certbot for housekeeping and in file paths; it
  20286. doesn't affect the content of the certificate itself. To see
  20287. certificate names, run @code{certbot certificates}.
  20288. Its default is the first provided domain.
  20289. @item @code{domains} (default: @code{()})
  20290. The first domain provided will be the subject CN of the certificate, and
  20291. all domains will be Subject Alternative Names on the certificate.
  20292. @item @code{challenge} (default: @code{#f})
  20293. The challenge type that has to be run by certbot. If @code{#f} is specified,
  20294. default to the HTTP challenge. If a value is specified, defaults to the
  20295. manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
  20296. the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
  20297. and gives Let's Encrypt permission to log the public IP address of the
  20298. requesting machine.
  20299. @item @code{authentication-hook} (default: @code{#f})
  20300. Command to be run in a shell once for each certificate challenge to be
  20301. answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
  20302. will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
  20303. contains the validation string and @code{$CERTBOT_TOKEN} contains the
  20304. file name of the resource requested when performing an HTTP-01 challenge.
  20305. @item @code{cleanup-hook} (default: @code{#f})
  20306. Command to be run in a shell once for each certificate challenge that
  20307. have been answered by the @code{auth-hook}. For this command, the shell
  20308. variables available in the @code{auth-hook} script are still available, and
  20309. additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
  20310. of the @code{auth-hook} script.
  20311. @item @code{deploy-hook} (default: @code{#f})
  20312. Command to be run in a shell once for each successfully issued
  20313. certificate. For this command, the shell variable
  20314. @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
  20315. example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
  20316. certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
  20317. contain a space-delimited list of renewed certificate domains (for
  20318. example, @samp{"example.com www.example.com"}.
  20319. @end table
  20320. @end deftp
  20321. For each @code{certificate-configuration}, the certificate is saved to
  20322. @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
  20323. saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
  20324. @node DNS Services
  20325. @subsection DNS Services
  20326. @cindex DNS (domain name system)
  20327. @cindex domain name system (DNS)
  20328. The @code{(gnu services dns)} module provides services related to the
  20329. @dfn{domain name system} (DNS). It provides a server service for hosting
  20330. an @emph{authoritative} DNS server for multiple zones, slave or master.
  20331. This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
  20332. caching and forwarding DNS server for the LAN, which uses
  20333. @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
  20334. @subsubheading Knot Service
  20335. An example configuration of an authoritative server for two zones, one master
  20336. and one slave, is:
  20337. @lisp
  20338. (define-zone-entries example.org.zone
  20339. ;; Name TTL Class Type Data
  20340. ("@@" "" "IN" "A" "127.0.0.1")
  20341. ("@@" "" "IN" "NS" "ns")
  20342. ("ns" "" "IN" "A" "127.0.0.1"))
  20343. (define master-zone
  20344. (knot-zone-configuration
  20345. (domain "example.org")
  20346. (zone (zone-file
  20347. (origin "example.org")
  20348. (entries example.org.zone)))))
  20349. (define slave-zone
  20350. (knot-zone-configuration
  20351. (domain "plop.org")
  20352. (dnssec-policy "default")
  20353. (master (list "plop-master"))))
  20354. (define plop-master
  20355. (knot-remote-configuration
  20356. (id "plop-master")
  20357. (address (list "208.76.58.171"))))
  20358. (operating-system
  20359. ;; ...
  20360. (services (cons* (service knot-service-type
  20361. (knot-configuration
  20362. (remotes (list plop-master))
  20363. (zones (list master-zone slave-zone))))
  20364. ;; ...
  20365. %base-services)))
  20366. @end lisp
  20367. @deffn {Scheme Variable} knot-service-type
  20368. This is the type for the Knot DNS server.
  20369. Knot DNS is an authoritative DNS server, meaning that it can serve multiple
  20370. zones, that is to say domain names you would buy from a registrar. This server
  20371. is not a resolver, meaning that it can only resolve names for which it is
  20372. authoritative. This server can be configured to serve zones as a master server
  20373. or a slave server as a per-zone basis. Slave zones will get their data from
  20374. masters, and will serve it as an authoritative server. From the point of view
  20375. of a resolver, there is no difference between master and slave.
  20376. The following data types are used to configure the Knot DNS server:
  20377. @end deffn
  20378. @deftp {Data Type} knot-key-configuration
  20379. Data type representing a key.
  20380. This type has the following parameters:
  20381. @table @asis
  20382. @item @code{id} (default: @code{""})
  20383. An identifier for other configuration fields to refer to this key. IDs must
  20384. be unique and must not be empty.
  20385. @item @code{algorithm} (default: @code{#f})
  20386. The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
  20387. @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
  20388. and @code{'hmac-sha512}.
  20389. @item @code{secret} (default: @code{""})
  20390. The secret key itself.
  20391. @end table
  20392. @end deftp
  20393. @deftp {Data Type} knot-acl-configuration
  20394. Data type representing an Access Control List (ACL) configuration.
  20395. This type has the following parameters:
  20396. @table @asis
  20397. @item @code{id} (default: @code{""})
  20398. An identifier for other configuration fields to refer to this key. IDs must be
  20399. unique and must not be empty.
  20400. @item @code{address} (default: @code{'()})
  20401. An ordered list of IP addresses, network subnets, or network ranges represented
  20402. with strings. The query must match one of them. Empty value means that
  20403. address match is not required.
  20404. @item @code{key} (default: @code{'()})
  20405. An ordered list of references to keys represented with strings. The string
  20406. must match a key ID defined in a @code{knot-key-configuration}. No key means
  20407. that a key is not require to match that ACL.
  20408. @item @code{action} (default: @code{'()})
  20409. An ordered list of actions that are permitted or forbidden by this ACL@. Possible
  20410. values are lists of zero or more elements from @code{'transfer}, @code{'notify}
  20411. and @code{'update}.
  20412. @item @code{deny?} (default: @code{#f})
  20413. When true, the ACL defines restrictions. Listed actions are forbidden. When
  20414. false, listed actions are allowed.
  20415. @end table
  20416. @end deftp
  20417. @deftp {Data Type} zone-entry
  20418. Data type representing a record entry in a zone file.
  20419. This type has the following parameters:
  20420. @table @asis
  20421. @item @code{name} (default: @code{"@@"})
  20422. The name of the record. @code{"@@"} refers to the origin of the zone. Names
  20423. are relative to the origin of the zone. For example, in the @code{example.org}
  20424. zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
  20425. Names ending with a dot are absolute, which means that @code{"ns.example.org."}
  20426. refers to @code{ns.example.org}.
  20427. @item @code{ttl} (default: @code{""})
  20428. The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
  20429. @item @code{class} (default: @code{"IN"})
  20430. The class of the record. Knot currently supports only @code{"IN"} and
  20431. partially @code{"CH"}.
  20432. @item @code{type} (default: @code{"A"})
  20433. The type of the record. Common types include A (IPv4 address), AAAA (IPv6
  20434. address), NS (Name Server) and MX (Mail eXchange). Many other types are
  20435. defined.
  20436. @item @code{data} (default: @code{""})
  20437. The data contained in the record. For instance an IP address associated with
  20438. an A record, or a domain name associated with an NS record. Remember that
  20439. domain names are relative to the origin unless they end with a dot.
  20440. @end table
  20441. @end deftp
  20442. @deftp {Data Type} zone-file
  20443. Data type representing the content of a zone file.
  20444. This type has the following parameters:
  20445. @table @asis
  20446. @item @code{entries} (default: @code{'()})
  20447. The list of entries. The SOA record is taken care of, so you don't need to
  20448. put it in the list of entries. This list should probably contain an entry
  20449. for your primary authoritative DNS server. Other than using a list of entries
  20450. directly, you can use @code{define-zone-entries} to define a object containing
  20451. the list of entries more easily, that you can later pass to the @code{entries}
  20452. field of the @code{zone-file}.
  20453. @item @code{origin} (default: @code{""})
  20454. The name of your zone. This parameter cannot be empty.
  20455. @item @code{ns} (default: @code{"ns"})
  20456. The domain of your primary authoritative DNS server. The name is relative to
  20457. the origin, unless it ends with a dot. It is mandatory that this primary
  20458. DNS server corresponds to an NS record in the zone and that it is associated
  20459. to an IP address in the list of entries.
  20460. @item @code{mail} (default: @code{"hostmaster"})
  20461. An email address people can contact you at, as the owner of the zone. This
  20462. is translated as @code{<mail>@@<origin>}.
  20463. @item @code{serial} (default: @code{1})
  20464. The serial number of the zone. As this is used to keep track of changes by
  20465. both slaves and resolvers, it is mandatory that it @emph{never} decreases.
  20466. Always increment it when you make a change in your zone.
  20467. @item @code{refresh} (default: @code{(* 2 24 3600)})
  20468. The frequency at which slaves will do a zone transfer. This value is a number
  20469. of seconds. It can be computed by multiplications or with
  20470. @code{(string->duration)}.
  20471. @item @code{retry} (default: @code{(* 15 60)})
  20472. The period after which a slave will retry to contact its master when it fails
  20473. to do so a first time.
  20474. @item @code{expiry} (default: @code{(* 14 24 3600)})
  20475. Default TTL of records. Existing records are considered correct for at most
  20476. this amount of time. After this period, resolvers will invalidate their cache
  20477. and check again that it still exists.
  20478. @item @code{nx} (default: @code{3600})
  20479. Default TTL of inexistant records. This delay is usually short because you want
  20480. your new domains to reach everyone quickly.
  20481. @end table
  20482. @end deftp
  20483. @deftp {Data Type} knot-remote-configuration
  20484. Data type representing a remote configuration.
  20485. This type has the following parameters:
  20486. @table @asis
  20487. @item @code{id} (default: @code{""})
  20488. An identifier for other configuration fields to refer to this remote. IDs must
  20489. be unique and must not be empty.
  20490. @item @code{address} (default: @code{'()})
  20491. An ordered list of destination IP addresses. Addresses are tried in sequence.
  20492. An optional port can be given with the @@ separator. For instance:
  20493. @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
  20494. @item @code{via} (default: @code{'()})
  20495. An ordered list of source IP addresses. An empty list will have Knot choose
  20496. an appropriate source IP@. An optional port can be given with the @@ separator.
  20497. The default is to choose at random.
  20498. @item @code{key} (default: @code{#f})
  20499. A reference to a key, that is a string containing the identifier of a key
  20500. defined in a @code{knot-key-configuration} field.
  20501. @end table
  20502. @end deftp
  20503. @deftp {Data Type} knot-keystore-configuration
  20504. Data type representing a keystore to hold dnssec keys.
  20505. This type has the following parameters:
  20506. @table @asis
  20507. @item @code{id} (default: @code{""})
  20508. The id of the keystore. It must not be empty.
  20509. @item @code{backend} (default: @code{'pem})
  20510. The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
  20511. @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
  20512. The configuration string of the backend. An example for the PKCS#11 is:
  20513. @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
  20514. For the pem backend, the string represents a path in the file system.
  20515. @end table
  20516. @end deftp
  20517. @deftp {Data Type} knot-policy-configuration
  20518. Data type representing a dnssec policy. Knot DNS is able to automatically
  20519. sign your zones. It can either generate and manage your keys automatically or
  20520. use keys that you generate.
  20521. Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
  20522. used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
  20523. zone. In order to be trusted, the KSK needs to be present in the parent zone
  20524. (usually a top-level domain). If your registrar supports dnssec, you will
  20525. have to send them your KSK's hash so they can add a DS record in their zone.
  20526. This is not automated and need to be done each time you change your KSK.
  20527. The policy also defines the lifetime of keys. Usually, ZSK can be changed
  20528. easily and use weaker cryptographic functions (they use lower parameters) in
  20529. order to sign records quickly, so they are changed often. The KSK however
  20530. requires manual interaction with the registrar, so they are changed less often
  20531. and use stronger parameters because they sign only one record.
  20532. This type has the following parameters:
  20533. @table @asis
  20534. @item @code{id} (default: @code{""})
  20535. The id of the policy. It must not be empty.
  20536. @item @code{keystore} (default: @code{"default"})
  20537. A reference to a keystore, that is a string containing the identifier of a
  20538. keystore defined in a @code{knot-keystore-configuration} field. The
  20539. @code{"default"} identifier means the default keystore (a kasp database that
  20540. was setup by this service).
  20541. @item @code{manual?} (default: @code{#f})
  20542. Whether the key management is manual or automatic.
  20543. @item @code{single-type-signing?} (default: @code{#f})
  20544. When @code{#t}, use the Single-Type Signing Scheme.
  20545. @item @code{algorithm} (default: @code{"ecdsap256sha256"})
  20546. An algorithm of signing keys and issued signatures.
  20547. @item @code{ksk-size} (default: @code{256})
  20548. The length of the KSK@. Note that this value is correct for the default
  20549. algorithm, but would be unsecure for other algorithms.
  20550. @item @code{zsk-size} (default: @code{256})
  20551. The length of the ZSK@. Note that this value is correct for the default
  20552. algorithm, but would be unsecure for other algorithms.
  20553. @item @code{dnskey-ttl} (default: @code{'default})
  20554. The TTL value for DNSKEY records added into zone apex. The special
  20555. @code{'default} value means same as the zone SOA TTL.
  20556. @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
  20557. The period between ZSK publication and the next rollover initiation.
  20558. @item @code{propagation-delay} (default: @code{(* 24 3600)})
  20559. An extra delay added for each key rollover step. This value should be high
  20560. enough to cover propagation of data from the master server to all slaves.
  20561. @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
  20562. A validity period of newly issued signatures.
  20563. @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
  20564. A period how long before a signature expiration the signature will be refreshed.
  20565. @item @code{nsec3?} (default: @code{#f})
  20566. When @code{#t}, NSEC3 will be used instead of NSEC.
  20567. @item @code{nsec3-iterations} (default: @code{5})
  20568. The number of additional times the hashing is performed.
  20569. @item @code{nsec3-salt-length} (default: @code{8})
  20570. The length of a salt field in octets, which is appended to the original owner
  20571. name before hashing.
  20572. @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
  20573. The validity period of newly issued salt field.
  20574. @end table
  20575. @end deftp
  20576. @deftp {Data Type} knot-zone-configuration
  20577. Data type representing a zone served by Knot.
  20578. This type has the following parameters:
  20579. @table @asis
  20580. @item @code{domain} (default: @code{""})
  20581. The domain served by this configuration. It must not be empty.
  20582. @item @code{file} (default: @code{""})
  20583. The file where this zone is saved. This parameter is ignored by master zones.
  20584. Empty means default location that depends on the domain name.
  20585. @item @code{zone} (default: @code{(zone-file)})
  20586. The content of the zone file. This parameter is ignored by slave zones. It
  20587. must contain a zone-file record.
  20588. @item @code{master} (default: @code{'()})
  20589. A list of master remotes. When empty, this zone is a master. When set, this
  20590. zone is a slave. This is a list of remotes identifiers.
  20591. @item @code{ddns-master} (default: @code{#f})
  20592. The main master. When empty, it defaults to the first master in the list of
  20593. masters.
  20594. @item @code{notify} (default: @code{'()})
  20595. A list of slave remote identifiers.
  20596. @item @code{acl} (default: @code{'()})
  20597. A list of acl identifiers.
  20598. @item @code{semantic-checks?} (default: @code{#f})
  20599. When set, this adds more semantic checks to the zone.
  20600. @item @code{disable-any?} (default: @code{#f})
  20601. When set, this forbids queries of the ANY type.
  20602. @item @code{zonefile-sync} (default: @code{0})
  20603. The delay between a modification in memory and on disk. 0 means immediate
  20604. synchronization.
  20605. @item @code{zonefile-load} (default: @code{#f})
  20606. The way the zone file contents are applied during zone load. Possible values
  20607. are:
  20608. @itemize
  20609. @item @code{#f} for using the default value from Knot,
  20610. @item @code{'none} for not using the zone file at all,
  20611. @item @code{'difference} for computing the difference between already available
  20612. contents and zone contents and applying it to the current zone contents,
  20613. @item @code{'difference-no-serial} for the same as @code{'difference}, but
  20614. ignoring the SOA serial in the zone file, while the server takes care of it
  20615. automatically.
  20616. @item @code{'whole} for loading zone contents from the zone file.
  20617. @end itemize
  20618. @item @code{journal-content} (default: @code{#f})
  20619. The way the journal is used to store zone and its changes. Possible values
  20620. are @code{'none} to not use it at all, @code{'changes} to store changes and
  20621. @code{'all} to store contents. @code{#f} does not set this option, so the
  20622. default value from Knot is used.
  20623. @item @code{max-journal-usage} (default: @code{#f})
  20624. The maximum size for the journal on disk. @code{#f} does not set this option,
  20625. so the default value from Knot is used.
  20626. @item @code{max-journal-depth} (default: @code{#f})
  20627. The maximum size of the history. @code{#f} does not set this option, so the
  20628. default value from Knot is used.
  20629. @item @code{max-zone-size} (default: @code{#f})
  20630. The maximum size of the zone file. This limit is enforced for incoming
  20631. transfer and updates. @code{#f} does not set this option, so the default
  20632. value from Knot is used.
  20633. @item @code{dnssec-policy} (default: @code{#f})
  20634. A reference to a @code{knot-policy-configuration} record, or the special
  20635. name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
  20636. on this zone.
  20637. @item @code{serial-policy} (default: @code{'increment})
  20638. A policy between @code{'increment} and @code{'unixtime}.
  20639. @end table
  20640. @end deftp
  20641. @deftp {Data Type} knot-configuration
  20642. Data type representing the Knot configuration.
  20643. This type has the following parameters:
  20644. @table @asis
  20645. @item @code{knot} (default: @code{knot})
  20646. The Knot package.
  20647. @item @code{run-directory} (default: @code{"/var/run/knot"})
  20648. The run directory. This directory will be used for pid file and sockets.
  20649. @item @code{includes} (default: @code{'()})
  20650. A list of strings or file-like objects denoting other files that must be
  20651. included at the top of the configuration file.
  20652. @cindex secrets, Knot service
  20653. This can be used to manage secrets out-of-band. For example, secret
  20654. keys may be stored in an out-of-band file not managed by Guix, and
  20655. thus not visible in @file{/gnu/store}---e.g., you could store secret
  20656. key configuration in @file{/etc/knot/secrets.conf} and add this file
  20657. to the @code{includes} list.
  20658. One can generate a secret tsig key (for nsupdate and zone transfers with the
  20659. keymgr command from the knot package. Note that the package is not automatically
  20660. installed by the service. The following example shows how to generate a new
  20661. tsig key:
  20662. @example
  20663. keymgr -t mysecret > /etc/knot/secrets.conf
  20664. chmod 600 /etc/knot/secrets.conf
  20665. @end example
  20666. Also note that the generated key will be named @var{mysecret}, so it is the
  20667. name that needs to be used in the @var{key} field of the
  20668. @code{knot-acl-configuration} record and in other places that need to refer
  20669. to that key.
  20670. It can also be used to add configuration not supported by this interface.
  20671. @item @code{listen-v4} (default: @code{"0.0.0.0"})
  20672. An ip address on which to listen.
  20673. @item @code{listen-v6} (default: @code{"::"})
  20674. An ip address on which to listen.
  20675. @item @code{listen-port} (default: @code{53})
  20676. A port on which to listen.
  20677. @item @code{keys} (default: @code{'()})
  20678. The list of knot-key-configuration used by this configuration.
  20679. @item @code{acls} (default: @code{'()})
  20680. The list of knot-acl-configuration used by this configuration.
  20681. @item @code{remotes} (default: @code{'()})
  20682. The list of knot-remote-configuration used by this configuration.
  20683. @item @code{zones} (default: @code{'()})
  20684. The list of knot-zone-configuration used by this configuration.
  20685. @end table
  20686. @end deftp
  20687. @subsubheading Knot Resolver Service
  20688. @deffn {Scheme Variable} knot-resolver-service-type
  20689. This is the type of the knot resolver service, whose value should be
  20690. an @code{knot-resolver-configuration} object as in this example:
  20691. @lisp
  20692. (service knot-resolver-service-type
  20693. (knot-resolver-configuration
  20694. (kresd-config-file (plain-file "kresd.conf" "
  20695. net.listen('192.168.0.1', 5353)
  20696. user('knot-resolver', 'knot-resolver')
  20697. modules = @{ 'hints > iterate', 'stats', 'predict' @}
  20698. cache.size = 100 * MB
  20699. "))))
  20700. @end lisp
  20701. For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
  20702. @end deffn
  20703. @deftp {Data Type} knot-resolver-configuration
  20704. Data type representing the configuration of knot-resolver.
  20705. @table @asis
  20706. @item @code{package} (default: @var{knot-resolver})
  20707. Package object of the knot DNS resolver.
  20708. @item @code{kresd-config-file} (default: %kresd.conf)
  20709. File-like object of the kresd configuration file to use, by default it
  20710. will listen on @code{127.0.0.1} and @code{::1}.
  20711. @item @code{garbage-collection-interval} (default: 1000)
  20712. Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
  20713. @end table
  20714. @end deftp
  20715. @subsubheading Dnsmasq Service
  20716. @deffn {Scheme Variable} dnsmasq-service-type
  20717. This is the type of the dnsmasq service, whose value should be an
  20718. @code{dnsmasq-configuration} object as in this example:
  20719. @lisp
  20720. (service dnsmasq-service-type
  20721. (dnsmasq-configuration
  20722. (no-resolv? #t)
  20723. (servers '("192.168.1.1"))))
  20724. @end lisp
  20725. @end deffn
  20726. @deftp {Data Type} dnsmasq-configuration
  20727. Data type representing the configuration of dnsmasq.
  20728. @table @asis
  20729. @item @code{package} (default: @var{dnsmasq})
  20730. Package object of the dnsmasq server.
  20731. @item @code{no-hosts?} (default: @code{#f})
  20732. When true, don't read the hostnames in /etc/hosts.
  20733. @item @code{port} (default: @code{53})
  20734. The port to listen on. Setting this to zero completely disables DNS
  20735. responses, leaving only DHCP and/or TFTP functions.
  20736. @item @code{local-service?} (default: @code{#t})
  20737. Accept DNS queries only from hosts whose address is on a local subnet,
  20738. ie a subnet for which an interface exists on the server.
  20739. @item @code{listen-addresses} (default: @code{'()})
  20740. Listen on the given IP addresses.
  20741. @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
  20742. The file to read the IP address of the upstream nameservers from.
  20743. @item @code{no-resolv?} (default: @code{#f})
  20744. When true, don't read @var{resolv-file}.
  20745. @item @code{servers} (default: @code{'()})
  20746. Specify IP address of upstream servers directly.
  20747. @item @code{addresses} (default: @code{'()})
  20748. For each entry, specify an IP address to return for any host in the
  20749. given domains. Queries in the domains are never forwarded and always
  20750. replied to with the specified IP address.
  20751. This is useful for redirecting hosts locally, for example:
  20752. @lisp
  20753. (service dnsmasq-service-type
  20754. (dnsmasq-configuration
  20755. (addresses
  20756. '(; Redirect to a local web-server.
  20757. "/example.org/127.0.0.1"
  20758. ; Redirect subdomain to a specific IP.
  20759. "/subdomain.example.org/192.168.1.42"))))
  20760. @end lisp
  20761. Note that rules in @file{/etc/hosts} take precedence over this.
  20762. @item @code{cache-size} (default: @code{150})
  20763. Set the size of dnsmasq's cache. Setting the cache size to zero
  20764. disables caching.
  20765. @item @code{negative-cache?} (default: @code{#t})
  20766. When false, disable negative caching.
  20767. @item @code{tftp-enable?} (default: @code{#f})
  20768. Whether to enable the built-in TFTP server.
  20769. @item @code{tftp-no-fail?} (default: @code{#f})
  20770. If true, does not fail dnsmasq if the TFTP server could not start up.
  20771. @item @code{tftp-single-port?} (default: @code{#f})
  20772. Whether to use only one single port for TFTP.
  20773. @item @code{tftp-secure?} (default: @code{#f})
  20774. If true, only files owned by the user running the dnsmasq process are accessible.
  20775. If dnsmasq is being run as root, different rules apply:
  20776. @code{tftp-secure?} has no effect, but only files which have the
  20777. world-readable bit set are accessible.
  20778. @item @code{tftp-max} (default: @code{#f})
  20779. If set, sets the maximal number of concurrent connections allowed.
  20780. @item @code{tftp-mtu} (default: @code{#f})
  20781. If set, sets the MTU for TFTP packets to that value.
  20782. @item @code{tftp-no-blocksize?} (default: @code{#f})
  20783. If true, stops the TFTP server from negotiating the blocksize with a client.
  20784. @item @code{tftp-lowercase?} (default: @code{#f})
  20785. Whether to convert all filenames in TFTP requests to lowercase.
  20786. @item @code{tftp-port-range} (default: @code{#f})
  20787. If set, fixes the dynamical ports (one per client) to the given range
  20788. (@code{"<start>,<end>"}).
  20789. @item @code{tftp-root} (default: @code{/var/empty,lo})
  20790. Look for files to transfer using TFTP relative to the given directory.
  20791. When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
  20792. getting outside the specified root. Absolute paths (starting with @samp{/}) are
  20793. allowed, but they must be within the TFTP-root. If the optional interface
  20794. argument is given, the directory is only used for TFTP requests via that
  20795. interface.
  20796. @item @code{tftp-unique-root} (default: @code{#f})
  20797. If set, add the IP or hardware address of the TFTP client as a path component
  20798. on the end of the TFTP-root. Only valid if a TFTP root is set and the
  20799. directory exists. Defaults to adding IP address (in standard dotted-quad
  20800. format).
  20801. For instance, if @option{--tftp-root} is @samp{/tftp} and client
  20802. @samp{1.2.3.4} requests file @file{myfile} then the effective path will
  20803. be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
  20804. @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
  20805. append the MAC address instead, using lowercase zero padded digits
  20806. separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
  20807. resolving MAC addresses is only possible if the client is in the local
  20808. network or obtained a DHCP lease from dnsmasq.
  20809. @end table
  20810. @end deftp
  20811. @subsubheading ddclient Service
  20812. @cindex ddclient
  20813. The ddclient service described below runs the ddclient daemon, which takes
  20814. care of automatically updating DNS entries for service providers such as
  20815. @uref{https://dyn.com/dns/, Dyn}.
  20816. The following example show instantiates the service with its default
  20817. configuration:
  20818. @lisp
  20819. (service ddclient-service-type)
  20820. @end lisp
  20821. Note that ddclient needs to access credentials that are stored in a
  20822. @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
  20823. @code{secret-file} below). You are expected to create this file manually, in
  20824. an ``out-of-band'' fashion (you @emph{could} make this file part of the
  20825. service configuration, for instance by using @code{plain-file}, but it will be
  20826. world-readable @i{via} @file{/gnu/store}). See the examples in the
  20827. @file{share/ddclient} directory of the @code{ddclient} package.
  20828. @c %start of fragment
  20829. Available @code{ddclient-configuration} fields are:
  20830. @deftypevr {@code{ddclient-configuration} parameter} package ddclient
  20831. The ddclient package.
  20832. @end deftypevr
  20833. @deftypevr {@code{ddclient-configuration} parameter} integer daemon
  20834. The period after which ddclient will retry to check IP and domain name.
  20835. Defaults to @samp{300}.
  20836. @end deftypevr
  20837. @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
  20838. Use syslog for the output.
  20839. Defaults to @samp{#t}.
  20840. @end deftypevr
  20841. @deftypevr {@code{ddclient-configuration} parameter} string mail
  20842. Mail to user.
  20843. Defaults to @samp{"root"}.
  20844. @end deftypevr
  20845. @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
  20846. Mail failed update to user.
  20847. Defaults to @samp{"root"}.
  20848. @end deftypevr
  20849. @deftypevr {@code{ddclient-configuration} parameter} string pid
  20850. The ddclient PID file.
  20851. Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
  20852. @end deftypevr
  20853. @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
  20854. Enable SSL support.
  20855. Defaults to @samp{#t}.
  20856. @end deftypevr
  20857. @deftypevr {@code{ddclient-configuration} parameter} string user
  20858. Specifies the user name or ID that is used when running ddclient
  20859. program.
  20860. Defaults to @samp{"ddclient"}.
  20861. @end deftypevr
  20862. @deftypevr {@code{ddclient-configuration} parameter} string group
  20863. Group of the user who will run the ddclient program.
  20864. Defaults to @samp{"ddclient"}.
  20865. @end deftypevr
  20866. @deftypevr {@code{ddclient-configuration} parameter} string secret-file
  20867. Secret file which will be appended to @file{ddclient.conf} file. This
  20868. file contains credentials for use by ddclient. You are expected to
  20869. create it manually.
  20870. Defaults to @samp{"/etc/ddclient/secrets.conf"}.
  20871. @end deftypevr
  20872. @deftypevr {@code{ddclient-configuration} parameter} list extra-options
  20873. Extra options will be appended to @file{ddclient.conf} file.
  20874. Defaults to @samp{()}.
  20875. @end deftypevr
  20876. @c %end of fragment
  20877. @node VPN Services
  20878. @subsection VPN Services
  20879. @cindex VPN (virtual private network)
  20880. @cindex virtual private network (VPN)
  20881. The @code{(gnu services vpn)} module provides services related to
  20882. @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
  20883. your machine to connect to a VPN, and a @emph{server} service for your machine
  20884. to host a VPN@. Both services use @uref{https://openvpn.net/, OpenVPN}.
  20885. @deffn {Scheme Procedure} openvpn-client-service @
  20886. [#:config (openvpn-client-configuration)]
  20887. Return a service that runs @command{openvpn}, a VPN daemon, as a client.
  20888. @end deffn
  20889. @deffn {Scheme Procedure} openvpn-server-service @
  20890. [#:config (openvpn-server-configuration)]
  20891. Return a service that runs @command{openvpn}, a VPN daemon, as a server.
  20892. Both can be run simultaneously.
  20893. @end deffn
  20894. @c %automatically generated documentation
  20895. Available @code{openvpn-client-configuration} fields are:
  20896. @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
  20897. The OpenVPN package.
  20898. @end deftypevr
  20899. @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
  20900. The OpenVPN pid file.
  20901. Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
  20902. @end deftypevr
  20903. @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
  20904. The protocol (UDP or TCP) used to open a channel between clients and
  20905. servers.
  20906. Defaults to @samp{udp}.
  20907. @end deftypevr
  20908. @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
  20909. The device type used to represent the VPN connection.
  20910. Defaults to @samp{tun}.
  20911. @end deftypevr
  20912. If you do not have some of these files (eg.@: you use a username and
  20913. password), you can disable any of the following three fields by setting
  20914. it to @code{'disabled}.
  20915. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
  20916. The certificate authority to check connections against.
  20917. Defaults to @samp{"/etc/openvpn/ca.crt"}.
  20918. @end deftypevr
  20919. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
  20920. The certificate of the machine the daemon is running on. It should be
  20921. signed by the authority given in @code{ca}.
  20922. Defaults to @samp{"/etc/openvpn/client.crt"}.
  20923. @end deftypevr
  20924. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
  20925. The key of the machine the daemon is running on. It must be the key whose
  20926. certificate is @code{cert}.
  20927. Defaults to @samp{"/etc/openvpn/client.key"}.
  20928. @end deftypevr
  20929. @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
  20930. Whether to use the lzo compression algorithm.
  20931. Defaults to @samp{#t}.
  20932. @end deftypevr
  20933. @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
  20934. Don't re-read key files across SIGUSR1 or --ping-restart.
  20935. Defaults to @samp{#t}.
  20936. @end deftypevr
  20937. @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
  20938. Don't close and reopen TUN/TAP device or run up/down scripts across
  20939. SIGUSR1 or --ping-restart restarts.
  20940. Defaults to @samp{#t}.
  20941. @end deftypevr
  20942. @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
  20943. (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
  20944. poll/epoll/select prior to the write operation.
  20945. Defaults to @samp{#f}.
  20946. @end deftypevr
  20947. @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
  20948. Verbosity level.
  20949. Defaults to @samp{3}.
  20950. @end deftypevr
  20951. @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
  20952. Add an additional layer of HMAC authentication on top of the TLS control
  20953. channel to protect against DoS attacks.
  20954. Defaults to @samp{#f}.
  20955. @end deftypevr
  20956. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
  20957. Authenticate with server using username/password. The option is a file
  20958. containing username/password on 2 lines. Do not use a file-like object as it
  20959. would be added to the store and readable by any user.
  20960. Defaults to @samp{'disabled}.
  20961. @end deftypevr
  20962. @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
  20963. Whether to check the server certificate has server usage extension.
  20964. Defaults to @samp{#t}.
  20965. @end deftypevr
  20966. @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
  20967. Bind to a specific local port number.
  20968. Defaults to @samp{#f}.
  20969. @end deftypevr
  20970. @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
  20971. Retry resolving server address.
  20972. Defaults to @samp{#t}.
  20973. @end deftypevr
  20974. @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
  20975. A list of remote servers to connect to.
  20976. Defaults to @samp{()}.
  20977. Available @code{openvpn-remote-configuration} fields are:
  20978. @deftypevr {@code{openvpn-remote-configuration} parameter} string name
  20979. Server name.
  20980. Defaults to @samp{"my-server"}.
  20981. @end deftypevr
  20982. @deftypevr {@code{openvpn-remote-configuration} parameter} number port
  20983. Port number the server listens to.
  20984. Defaults to @samp{1194}.
  20985. @end deftypevr
  20986. @end deftypevr
  20987. @c %end of automatic openvpn-client documentation
  20988. @c %automatically generated documentation
  20989. Available @code{openvpn-server-configuration} fields are:
  20990. @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
  20991. The OpenVPN package.
  20992. @end deftypevr
  20993. @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
  20994. The OpenVPN pid file.
  20995. Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
  20996. @end deftypevr
  20997. @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
  20998. The protocol (UDP or TCP) used to open a channel between clients and
  20999. servers.
  21000. Defaults to @samp{udp}.
  21001. @end deftypevr
  21002. @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
  21003. The device type used to represent the VPN connection.
  21004. Defaults to @samp{tun}.
  21005. @end deftypevr
  21006. If you do not have some of these files (eg.@: you use a username and
  21007. password), you can disable any of the following three fields by setting
  21008. it to @code{'disabled}.
  21009. @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
  21010. The certificate authority to check connections against.
  21011. Defaults to @samp{"/etc/openvpn/ca.crt"}.
  21012. @end deftypevr
  21013. @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
  21014. The certificate of the machine the daemon is running on. It should be
  21015. signed by the authority given in @code{ca}.
  21016. Defaults to @samp{"/etc/openvpn/client.crt"}.
  21017. @end deftypevr
  21018. @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
  21019. The key of the machine the daemon is running on. It must be the key whose
  21020. certificate is @code{cert}.
  21021. Defaults to @samp{"/etc/openvpn/client.key"}.
  21022. @end deftypevr
  21023. @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
  21024. Whether to use the lzo compression algorithm.
  21025. Defaults to @samp{#t}.
  21026. @end deftypevr
  21027. @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
  21028. Don't re-read key files across SIGUSR1 or --ping-restart.
  21029. Defaults to @samp{#t}.
  21030. @end deftypevr
  21031. @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
  21032. Don't close and reopen TUN/TAP device or run up/down scripts across
  21033. SIGUSR1 or --ping-restart restarts.
  21034. Defaults to @samp{#t}.
  21035. @end deftypevr
  21036. @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
  21037. (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
  21038. poll/epoll/select prior to the write operation.
  21039. Defaults to @samp{#f}.
  21040. @end deftypevr
  21041. @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
  21042. Verbosity level.
  21043. Defaults to @samp{3}.
  21044. @end deftypevr
  21045. @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
  21046. Add an additional layer of HMAC authentication on top of the TLS control
  21047. channel to protect against DoS attacks.
  21048. Defaults to @samp{#f}.
  21049. @end deftypevr
  21050. @deftypevr {@code{openvpn-server-configuration} parameter} number port
  21051. Specifies the port number on which the server listens.
  21052. Defaults to @samp{1194}.
  21053. @end deftypevr
  21054. @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
  21055. An ip and mask specifying the subnet inside the virtual network.
  21056. Defaults to @samp{"10.8.0.0 255.255.255.0"}.
  21057. @end deftypevr
  21058. @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
  21059. A CIDR notation specifying the IPv6 subnet inside the virtual network.
  21060. Defaults to @samp{#f}.
  21061. @end deftypevr
  21062. @deftypevr {@code{openvpn-server-configuration} parameter} string dh
  21063. The Diffie-Hellman parameters file.
  21064. Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
  21065. @end deftypevr
  21066. @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
  21067. The file that records client IPs.
  21068. Defaults to @samp{"/etc/openvpn/ipp.txt"}.
  21069. @end deftypevr
  21070. @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
  21071. When true, the server will act as a gateway for its clients.
  21072. Defaults to @samp{#f}.
  21073. @end deftypevr
  21074. @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
  21075. When true, clients are allowed to talk to each other inside the VPN.
  21076. Defaults to @samp{#f}.
  21077. @end deftypevr
  21078. @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
  21079. Causes ping-like messages to be sent back and forth over the link so
  21080. that each side knows when the other side has gone down. @code{keepalive}
  21081. requires a pair. The first element is the period of the ping sending,
  21082. and the second element is the timeout before considering the other side
  21083. down.
  21084. @end deftypevr
  21085. @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
  21086. The maximum number of clients.
  21087. Defaults to @samp{100}.
  21088. @end deftypevr
  21089. @deftypevr {@code{openvpn-server-configuration} parameter} string status
  21090. The status file. This file shows a small report on current connection.
  21091. It is truncated and rewritten every minute.
  21092. Defaults to @samp{"/var/run/openvpn/status"}.
  21093. @end deftypevr
  21094. @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
  21095. The list of configuration for some clients.
  21096. Defaults to @samp{()}.
  21097. Available @code{openvpn-ccd-configuration} fields are:
  21098. @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
  21099. Client name.
  21100. Defaults to @samp{"client"}.
  21101. @end deftypevr
  21102. @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
  21103. Client own network
  21104. Defaults to @samp{#f}.
  21105. @end deftypevr
  21106. @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
  21107. Client VPN IP.
  21108. Defaults to @samp{#f}.
  21109. @end deftypevr
  21110. @end deftypevr
  21111. @c %end of automatic openvpn-server documentation
  21112. @node Network File System
  21113. @subsection Network File System
  21114. @cindex NFS
  21115. The @code{(gnu services nfs)} module provides the following services,
  21116. which are most commonly used in relation to mounting or exporting
  21117. directory trees as @dfn{network file systems} (NFS).
  21118. While it is possible to use the individual components that together make
  21119. up a Network File System service, we recommended to configure an NFS
  21120. server with the @code{nfs-service-type}.
  21121. @subsubheading NFS Service
  21122. @cindex NFS, server
  21123. The NFS service takes care of setting up all NFS component services,
  21124. kernel configuration file systems, and installs configuration files in
  21125. the locations that NFS expects.
  21126. @defvr {Scheme Variable} nfs-service-type
  21127. A service type for a complete NFS server.
  21128. @end defvr
  21129. @deftp {Data Type} nfs-configuration
  21130. This data type represents the configuration of the NFS service and all
  21131. of its subsystems.
  21132. It has the following parameters:
  21133. @table @asis
  21134. @item @code{nfs-utils} (default: @code{nfs-utils})
  21135. The nfs-utils package to use.
  21136. @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
  21137. If a list of string values is provided, the @command{rpc.nfsd} daemon
  21138. will be limited to supporting the given versions of the NFS protocol.
  21139. @item @code{exports} (default: @code{'()})
  21140. This is a list of directories the NFS server should export. Each entry
  21141. is a list consisting of two elements: a directory name and a string
  21142. containing all options. This is an example in which the directory
  21143. @file{/export} is served to all NFS clients as a read-only share:
  21144. @lisp
  21145. (nfs-configuration
  21146. (exports
  21147. '(("/export"
  21148. "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
  21149. @end lisp
  21150. @item @code{rpcmountd-port} (default: @code{#f})
  21151. The network port that the @command{rpc.mountd} daemon should use.
  21152. @item @code{rpcstatd-port} (default: @code{#f})
  21153. The network port that the @command{rpc.statd} daemon should use.
  21154. @item @code{rpcbind} (default: @code{rpcbind})
  21155. The rpcbind package to use.
  21156. @item @code{idmap-domain} (default: @code{"localdomain"})
  21157. The local NFSv4 domain name.
  21158. @item @code{nfsd-port} (default: @code{2049})
  21159. The network port that the @command{nfsd} daemon should use.
  21160. @item @code{nfsd-threads} (default: @code{8})
  21161. The number of threads used by the @command{nfsd} daemon.
  21162. @item @code{nfsd-tcp?} (default: @code{#t})
  21163. Whether the @command{nfsd} daemon should listen on a TCP socket.
  21164. @item @code{nfsd-udp?} (default: @code{#f})
  21165. Whether the @command{nfsd} daemon should listen on a UDP socket.
  21166. @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  21167. The directory where the pipefs file system is mounted.
  21168. @item @code{debug} (default: @code{'()"})
  21169. A list of subsystems for which debugging output should be enabled. This
  21170. is a list of symbols. Any of these symbols are valid: @code{nfsd},
  21171. @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
  21172. @end table
  21173. @end deftp
  21174. If you don't need a complete NFS service or prefer to build it yourself
  21175. you can use the individual component services that are documented below.
  21176. @subsubheading RPC Bind Service
  21177. @cindex rpcbind
  21178. The RPC Bind service provides a facility to map program numbers into
  21179. universal addresses.
  21180. Many NFS related services use this facility. Hence it is automatically
  21181. started when a dependent service starts.
  21182. @defvr {Scheme Variable} rpcbind-service-type
  21183. A service type for the RPC portmapper daemon.
  21184. @end defvr
  21185. @deftp {Data Type} rpcbind-configuration
  21186. Data type representing the configuration of the RPC Bind Service.
  21187. This type has the following parameters:
  21188. @table @asis
  21189. @item @code{rpcbind} (default: @code{rpcbind})
  21190. The rpcbind package to use.
  21191. @item @code{warm-start?} (default: @code{#t})
  21192. If this parameter is @code{#t}, then the daemon will read a
  21193. state file on startup thus reloading state information saved by a previous
  21194. instance.
  21195. @end table
  21196. @end deftp
  21197. @subsubheading Pipefs Pseudo File System
  21198. @cindex pipefs
  21199. @cindex rpc_pipefs
  21200. The pipefs file system is used to transfer NFS related data
  21201. between the kernel and user space programs.
  21202. @defvr {Scheme Variable} pipefs-service-type
  21203. A service type for the pipefs pseudo file system.
  21204. @end defvr
  21205. @deftp {Data Type} pipefs-configuration
  21206. Data type representing the configuration of the pipefs pseudo file system service.
  21207. This type has the following parameters:
  21208. @table @asis
  21209. @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  21210. The directory to which the file system is to be attached.
  21211. @end table
  21212. @end deftp
  21213. @subsubheading GSS Daemon Service
  21214. @cindex GSSD
  21215. @cindex GSS
  21216. @cindex global security system
  21217. The @dfn{global security system} (GSS) daemon provides strong security for RPC
  21218. based protocols.
  21219. Before exchanging RPC requests an RPC client must establish a security
  21220. context. Typically this is done using the Kerberos command @command{kinit}
  21221. or automatically at login time using PAM services (@pxref{Kerberos Services}).
  21222. @defvr {Scheme Variable} gss-service-type
  21223. A service type for the Global Security System (GSS) daemon.
  21224. @end defvr
  21225. @deftp {Data Type} gss-configuration
  21226. Data type representing the configuration of the GSS daemon service.
  21227. This type has the following parameters:
  21228. @table @asis
  21229. @item @code{nfs-utils} (default: @code{nfs-utils})
  21230. The package in which the @command{rpc.gssd} command is to be found.
  21231. @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  21232. The directory where the pipefs file system is mounted.
  21233. @end table
  21234. @end deftp
  21235. @subsubheading IDMAP Daemon Service
  21236. @cindex idmapd
  21237. @cindex name mapper
  21238. The idmap daemon service provides mapping between user IDs and user names.
  21239. Typically it is required in order to access file systems mounted via NFSv4.
  21240. @defvr {Scheme Variable} idmap-service-type
  21241. A service type for the Identity Mapper (IDMAP) daemon.
  21242. @end defvr
  21243. @deftp {Data Type} idmap-configuration
  21244. Data type representing the configuration of the IDMAP daemon service.
  21245. This type has the following parameters:
  21246. @table @asis
  21247. @item @code{nfs-utils} (default: @code{nfs-utils})
  21248. The package in which the @command{rpc.idmapd} command is to be found.
  21249. @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  21250. The directory where the pipefs file system is mounted.
  21251. @item @code{domain} (default: @code{#f})
  21252. The local NFSv4 domain name.
  21253. This must be a string or @code{#f}.
  21254. If it is @code{#f} then the daemon will use the host's fully qualified domain name.
  21255. @item @code{verbosity} (default: @code{0})
  21256. The verbosity level of the daemon.
  21257. @end table
  21258. @end deftp
  21259. @node Continuous Integration
  21260. @subsection Continuous Integration
  21261. @cindex continuous integration
  21262. @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
  21263. continuous integration tool for Guix. It can be used both for development and
  21264. for providing substitutes to others (@pxref{Substitutes}).
  21265. The @code{(gnu services cuirass)} module provides the following service.
  21266. @defvr {Scheme Procedure} cuirass-service-type
  21267. The type of the Cuirass service. Its value must be a
  21268. @code{cuirass-configuration} object, as described below.
  21269. @end defvr
  21270. To add build jobs, you have to set the @code{specifications} field of the
  21271. configuration. Here is an example of a service that polls the Guix repository
  21272. and builds the packages from a manifest. Some of the packages are defined in
  21273. the @code{"custom-packages"} input, which is the equivalent of
  21274. @env{GUIX_PACKAGE_PATH}.
  21275. @lisp
  21276. (define %cuirass-specs
  21277. #~(list
  21278. '((#:name . "my-manifest")
  21279. (#:load-path-inputs . ("guix"))
  21280. (#:package-path-inputs . ("custom-packages"))
  21281. (#:proc-input . "guix")
  21282. (#:proc-file . "build-aux/cuirass/gnu-system.scm")
  21283. (#:proc . cuirass-jobs)
  21284. (#:proc-args . ((subset . "manifests")
  21285. (systems . ("x86_64-linux"))
  21286. (manifests . (("config" . "guix/manifest.scm")))))
  21287. (#:inputs . (((#:name . "guix")
  21288. (#:url . "git://git.savannah.gnu.org/guix.git")
  21289. (#:load-path . ".")
  21290. (#:branch . "master")
  21291. (#:no-compile? . #t))
  21292. ((#:name . "config")
  21293. (#:url . "https://git.example.org/config.git")
  21294. (#:load-path . ".")
  21295. (#:branch . "master")
  21296. (#:no-compile? . #t))
  21297. ((#:name . "custom-packages")
  21298. (#:url . "https://git.example.org/custom-packages.git")
  21299. (#:load-path . ".")
  21300. (#:branch . "master")
  21301. (#:no-compile? . #t)))))))
  21302. (service cuirass-service-type
  21303. (cuirass-configuration
  21304. (specifications %cuirass-specs)))
  21305. @end lisp
  21306. While information related to build jobs is located directly in the
  21307. specifications, global settings for the @command{cuirass} process are
  21308. accessible in other @code{cuirass-configuration} fields.
  21309. @deftp {Data Type} cuirass-configuration
  21310. Data type representing the configuration of Cuirass.
  21311. @table @asis
  21312. @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
  21313. Location of the log file.
  21314. @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
  21315. Location of the log file used by the web interface.
  21316. @item @code{queries-log-file} (default: @code{#f})
  21317. Location of the SQL queries log file. By default, SQL queries logging is
  21318. disabled.
  21319. @item @code{web-queries-log-file} (default: @code{#f})
  21320. Location of the web SQL queries log file. By default, web SQL queries
  21321. logging is disabled.
  21322. @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
  21323. Location of the repository cache.
  21324. @item @code{user} (default: @code{"cuirass"})
  21325. Owner of the @code{cuirass} process.
  21326. @item @code{group} (default: @code{"cuirass"})
  21327. Owner's group of the @code{cuirass} process.
  21328. @item @code{interval} (default: @code{60})
  21329. Number of seconds between the poll of the repositories followed by the
  21330. Cuirass jobs.
  21331. @item @code{queue-size} (default: @code{1})
  21332. Size of the database writer queue.
  21333. @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
  21334. Location of sqlite database which contains the build results and previously
  21335. added specifications.
  21336. @item @code{ttl} (default: @code{(* 30 24 3600)})
  21337. Specifies the time-to-live (TTL) in seconds of garbage collector roots that
  21338. are registered for build results. This means that build results are protected
  21339. from garbage collection for at least @var{ttl} seconds.
  21340. @item @code{port} (default: @code{8081})
  21341. Port number used by the HTTP server.
  21342. @item @code{host} (default: @code{"localhost"})
  21343. Listen on the network interface for @var{host}. The default is to
  21344. accept connections from localhost.
  21345. @item @code{specifications} (default: @code{#~'()})
  21346. A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
  21347. where a specification is an association list
  21348. (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
  21349. keys are keywords (@code{#:keyword-example}) as shown in the example
  21350. above.
  21351. @item @code{use-substitutes?} (default: @code{#f})
  21352. This allows using substitutes to avoid building every dependencies of a job
  21353. from source.
  21354. @item @code{one-shot?} (default: @code{#f})
  21355. Only evaluate specifications and build derivations once.
  21356. @item @code{fallback?} (default: @code{#f})
  21357. When substituting a pre-built binary fails, fall back to building
  21358. packages locally.
  21359. @item @code{extra-options} (default: @code{'()})
  21360. Extra options to pass when running the Cuirass processes.
  21361. @item @code{cuirass} (default: @code{cuirass})
  21362. The Cuirass package to use.
  21363. @end table
  21364. @end deftp
  21365. @node Power Management Services
  21366. @subsection Power Management Services
  21367. @cindex tlp
  21368. @cindex power management with TLP
  21369. @subsubheading TLP daemon
  21370. The @code{(gnu services pm)} module provides a Guix service definition
  21371. for the Linux power management tool TLP.
  21372. TLP enables various powersaving modes in userspace and kernel.
  21373. Contrary to @code{upower-service}, it is not a passive,
  21374. monitoring tool, as it will apply custom settings each time a new power
  21375. source is detected. More information can be found at
  21376. @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
  21377. @deffn {Scheme Variable} tlp-service-type
  21378. The service type for the TLP tool. The default settings are optimised
  21379. for battery life on most systems, but you can tweak them to your heart's
  21380. content by adding a valid @code{tlp-configuration}:
  21381. @lisp
  21382. (service tlp-service-type
  21383. (tlp-configuration
  21384. (cpu-scaling-governor-on-ac (list "performance"))
  21385. (sched-powersave-on-bat? #t)))
  21386. @end lisp
  21387. @end deffn
  21388. Each parameter definition is preceded by its type; for example,
  21389. @samp{boolean foo} indicates that the @code{foo} parameter
  21390. should be specified as a boolean. Types starting with
  21391. @code{maybe-} denote parameters that won't show up in TLP config file
  21392. when their value is @code{'disabled}.
  21393. @c The following documentation was initially generated by
  21394. @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
  21395. @c documentation is better, so we shouldn't hesitate to edit below as
  21396. @c needed. However if the change you want to make to this documentation
  21397. @c can be done in an automated way, it's probably easier to change
  21398. @c (generate-documentation) than to make it below and have to deal with
  21399. @c the churn as TLP updates.
  21400. Available @code{tlp-configuration} fields are:
  21401. @deftypevr {@code{tlp-configuration} parameter} package tlp
  21402. The TLP package.
  21403. @end deftypevr
  21404. @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
  21405. Set to true if you wish to enable TLP.
  21406. Defaults to @samp{#t}.
  21407. @end deftypevr
  21408. @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
  21409. Default mode when no power supply can be detected. Alternatives are AC
  21410. and BAT.
  21411. Defaults to @samp{"AC"}.
  21412. @end deftypevr
  21413. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
  21414. Number of seconds Linux kernel has to wait after the disk goes idle,
  21415. before syncing on AC.
  21416. Defaults to @samp{0}.
  21417. @end deftypevr
  21418. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
  21419. Same as @code{disk-idle-ac} but on BAT mode.
  21420. Defaults to @samp{2}.
  21421. @end deftypevr
  21422. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
  21423. Dirty pages flushing periodicity, expressed in seconds.
  21424. Defaults to @samp{15}.
  21425. @end deftypevr
  21426. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
  21427. Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
  21428. Defaults to @samp{60}.
  21429. @end deftypevr
  21430. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
  21431. CPU frequency scaling governor on AC mode. With intel_pstate driver,
  21432. alternatives are powersave and performance. With acpi-cpufreq driver,
  21433. alternatives are ondemand, powersave, performance and conservative.
  21434. Defaults to @samp{disabled}.
  21435. @end deftypevr
  21436. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
  21437. Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
  21438. Defaults to @samp{disabled}.
  21439. @end deftypevr
  21440. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
  21441. Set the min available frequency for the scaling governor on AC.
  21442. Defaults to @samp{disabled}.
  21443. @end deftypevr
  21444. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
  21445. Set the max available frequency for the scaling governor on AC.
  21446. Defaults to @samp{disabled}.
  21447. @end deftypevr
  21448. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
  21449. Set the min available frequency for the scaling governor on BAT.
  21450. Defaults to @samp{disabled}.
  21451. @end deftypevr
  21452. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
  21453. Set the max available frequency for the scaling governor on BAT.
  21454. Defaults to @samp{disabled}.
  21455. @end deftypevr
  21456. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
  21457. Limit the min P-state to control the power dissipation of the CPU, in AC
  21458. mode. Values are stated as a percentage of the available performance.
  21459. Defaults to @samp{disabled}.
  21460. @end deftypevr
  21461. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
  21462. Limit the max P-state to control the power dissipation of the CPU, in AC
  21463. mode. Values are stated as a percentage of the available performance.
  21464. Defaults to @samp{disabled}.
  21465. @end deftypevr
  21466. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
  21467. Same as @code{cpu-min-perf-on-ac} on BAT mode.
  21468. Defaults to @samp{disabled}.
  21469. @end deftypevr
  21470. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
  21471. Same as @code{cpu-max-perf-on-ac} on BAT mode.
  21472. Defaults to @samp{disabled}.
  21473. @end deftypevr
  21474. @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
  21475. Enable CPU turbo boost feature on AC mode.
  21476. Defaults to @samp{disabled}.
  21477. @end deftypevr
  21478. @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
  21479. Same as @code{cpu-boost-on-ac?} on BAT mode.
  21480. Defaults to @samp{disabled}.
  21481. @end deftypevr
  21482. @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
  21483. Allow Linux kernel to minimize the number of CPU cores/hyper-threads
  21484. used under light load conditions.
  21485. Defaults to @samp{#f}.
  21486. @end deftypevr
  21487. @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
  21488. Same as @code{sched-powersave-on-ac?} but on BAT mode.
  21489. Defaults to @samp{#t}.
  21490. @end deftypevr
  21491. @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
  21492. Enable Linux kernel NMI watchdog.
  21493. Defaults to @samp{#f}.
  21494. @end deftypevr
  21495. @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
  21496. For Linux kernels with PHC patch applied, change CPU voltages. An
  21497. example value would be @samp{"F:V F:V F:V F:V"}.
  21498. Defaults to @samp{disabled}.
  21499. @end deftypevr
  21500. @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
  21501. Set CPU performance versus energy saving policy on AC@. Alternatives are
  21502. performance, normal, powersave.
  21503. Defaults to @samp{"performance"}.
  21504. @end deftypevr
  21505. @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
  21506. Same as @code{energy-perf-policy-ac} but on BAT mode.
  21507. Defaults to @samp{"powersave"}.
  21508. @end deftypevr
  21509. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
  21510. Hard disk devices.
  21511. @end deftypevr
  21512. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
  21513. Hard disk advanced power management level.
  21514. @end deftypevr
  21515. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
  21516. Same as @code{disk-apm-bat} but on BAT mode.
  21517. @end deftypevr
  21518. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
  21519. Hard disk spin down timeout. One value has to be specified for each
  21520. declared hard disk.
  21521. Defaults to @samp{disabled}.
  21522. @end deftypevr
  21523. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
  21524. Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
  21525. Defaults to @samp{disabled}.
  21526. @end deftypevr
  21527. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
  21528. Select IO scheduler for disk devices. One value has to be specified for
  21529. each declared hard disk. Example alternatives are cfq, deadline and
  21530. noop.
  21531. Defaults to @samp{disabled}.
  21532. @end deftypevr
  21533. @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
  21534. SATA aggressive link power management (ALPM) level. Alternatives are
  21535. min_power, medium_power, max_performance.
  21536. Defaults to @samp{"max_performance"}.
  21537. @end deftypevr
  21538. @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
  21539. Same as @code{sata-linkpwr-ac} but on BAT mode.
  21540. Defaults to @samp{"min_power"}.
  21541. @end deftypevr
  21542. @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
  21543. Exclude specified SATA host devices for link power management.
  21544. Defaults to @samp{disabled}.
  21545. @end deftypevr
  21546. @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
  21547. Enable Runtime Power Management for AHCI controller and disks on AC
  21548. mode.
  21549. Defaults to @samp{disabled}.
  21550. @end deftypevr
  21551. @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
  21552. Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
  21553. Defaults to @samp{disabled}.
  21554. @end deftypevr
  21555. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
  21556. Seconds of inactivity before disk is suspended.
  21557. Defaults to @samp{15}.
  21558. @end deftypevr
  21559. @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
  21560. PCI Express Active State Power Management level. Alternatives are
  21561. default, performance, powersave.
  21562. Defaults to @samp{"performance"}.
  21563. @end deftypevr
  21564. @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
  21565. Same as @code{pcie-aspm-ac} but on BAT mode.
  21566. Defaults to @samp{"powersave"}.
  21567. @end deftypevr
  21568. @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
  21569. Radeon graphics clock speed level. Alternatives are low, mid, high,
  21570. auto, default.
  21571. Defaults to @samp{"high"}.
  21572. @end deftypevr
  21573. @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
  21574. Same as @code{radeon-power-ac} but on BAT mode.
  21575. Defaults to @samp{"low"}.
  21576. @end deftypevr
  21577. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
  21578. Radeon dynamic power management method (DPM). Alternatives are battery,
  21579. performance.
  21580. Defaults to @samp{"performance"}.
  21581. @end deftypevr
  21582. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
  21583. Same as @code{radeon-dpm-state-ac} but on BAT mode.
  21584. Defaults to @samp{"battery"}.
  21585. @end deftypevr
  21586. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
  21587. Radeon DPM performance level. Alternatives are auto, low, high.
  21588. Defaults to @samp{"auto"}.
  21589. @end deftypevr
  21590. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
  21591. Same as @code{radeon-dpm-perf-ac} but on BAT mode.
  21592. Defaults to @samp{"auto"}.
  21593. @end deftypevr
  21594. @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
  21595. Wifi power saving mode.
  21596. Defaults to @samp{#f}.
  21597. @end deftypevr
  21598. @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
  21599. Same as @code{wifi-power-ac?} but on BAT mode.
  21600. Defaults to @samp{#t}.
  21601. @end deftypevr
  21602. @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
  21603. Disable wake on LAN.
  21604. Defaults to @samp{#t}.
  21605. @end deftypevr
  21606. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
  21607. Timeout duration in seconds before activating audio power saving on
  21608. Intel HDA and AC97 devices. A value of 0 disables power saving.
  21609. Defaults to @samp{0}.
  21610. @end deftypevr
  21611. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
  21612. Same as @code{sound-powersave-ac} but on BAT mode.
  21613. Defaults to @samp{1}.
  21614. @end deftypevr
  21615. @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
  21616. Disable controller in powersaving mode on Intel HDA devices.
  21617. Defaults to @samp{#t}.
  21618. @end deftypevr
  21619. @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
  21620. Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
  21621. powered on again by releasing (and reinserting) the eject lever or by
  21622. pressing the disc eject button on newer models.
  21623. Defaults to @samp{#f}.
  21624. @end deftypevr
  21625. @deftypevr {@code{tlp-configuration} parameter} string bay-device
  21626. Name of the optical drive device to power off.
  21627. Defaults to @samp{"sr0"}.
  21628. @end deftypevr
  21629. @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
  21630. Runtime Power Management for PCI(e) bus devices. Alternatives are on
  21631. and auto.
  21632. Defaults to @samp{"on"}.
  21633. @end deftypevr
  21634. @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
  21635. Same as @code{runtime-pm-ac} but on BAT mode.
  21636. Defaults to @samp{"auto"}.
  21637. @end deftypevr
  21638. @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
  21639. Runtime Power Management for all PCI(e) bus devices, except blacklisted
  21640. ones.
  21641. Defaults to @samp{#t}.
  21642. @end deftypevr
  21643. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
  21644. Exclude specified PCI(e) device addresses from Runtime Power Management.
  21645. Defaults to @samp{disabled}.
  21646. @end deftypevr
  21647. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
  21648. Exclude PCI(e) devices assigned to the specified drivers from Runtime
  21649. Power Management.
  21650. @end deftypevr
  21651. @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
  21652. Enable USB autosuspend feature.
  21653. Defaults to @samp{#t}.
  21654. @end deftypevr
  21655. @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
  21656. Exclude specified devices from USB autosuspend.
  21657. Defaults to @samp{disabled}.
  21658. @end deftypevr
  21659. @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
  21660. Exclude WWAN devices from USB autosuspend.
  21661. Defaults to @samp{#t}.
  21662. @end deftypevr
  21663. @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
  21664. Include specified devices into USB autosuspend, even if they are already
  21665. excluded by the driver or via @code{usb-blacklist-wwan?}.
  21666. Defaults to @samp{disabled}.
  21667. @end deftypevr
  21668. @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
  21669. Enable USB autosuspend before shutdown.
  21670. Defaults to @samp{disabled}.
  21671. @end deftypevr
  21672. @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
  21673. Restore radio device state (bluetooth, wifi, wwan) from previous
  21674. shutdown on system startup.
  21675. Defaults to @samp{#f}.
  21676. @end deftypevr
  21677. @cindex thermald
  21678. @cindex CPU frequency scaling with thermald
  21679. @subsubheading Thermald daemon
  21680. The @code{(gnu services pm)} module provides an interface to
  21681. thermald, a CPU frequency scaling service which helps prevent overheating.
  21682. @defvr {Scheme Variable} thermald-service-type
  21683. This is the service type for
  21684. @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
  21685. Thermal Daemon, which is responsible for controlling the thermal state
  21686. of processors and preventing overheating.
  21687. @end defvr
  21688. @deftp {Data Type} thermald-configuration
  21689. Data type representing the configuration of @code{thermald-service-type}.
  21690. @table @asis
  21691. @item @code{ignore-cpuid-check?} (default: @code{#f})
  21692. Ignore cpuid check for supported CPU models.
  21693. @item @code{thermald} (default: @var{thermald})
  21694. Package object of thermald.
  21695. @end table
  21696. @end deftp
  21697. @node Audio Services
  21698. @subsection Audio Services
  21699. The @code{(gnu services audio)} module provides a service to start MPD
  21700. (the Music Player Daemon).
  21701. @cindex mpd
  21702. @subsubheading Music Player Daemon
  21703. The Music Player Daemon (MPD) is a service that can play music while
  21704. being controlled from the local machine or over the network by a variety
  21705. of clients.
  21706. The following example shows how one might run @code{mpd} as user
  21707. @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
  21708. @lisp
  21709. (service mpd-service-type
  21710. (mpd-configuration
  21711. (user "bob")
  21712. (port "6666")))
  21713. @end lisp
  21714. @defvr {Scheme Variable} mpd-service-type
  21715. The service type for @command{mpd}
  21716. @end defvr
  21717. @deftp {Data Type} mpd-configuration
  21718. Data type representing the configuration of @command{mpd}.
  21719. @table @asis
  21720. @item @code{user} (default: @code{"mpd"})
  21721. The user to run mpd as.
  21722. @item @code{music-dir} (default: @code{"~/Music"})
  21723. The directory to scan for music files.
  21724. @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
  21725. The directory to store playlists.
  21726. @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
  21727. The location of the music database.
  21728. @item @code{state-file} (default: @code{"~/.mpd/state"})
  21729. The location of the file that stores current MPD's state.
  21730. @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
  21731. The location of the sticker database.
  21732. @item @code{port} (default: @code{"6600"})
  21733. The port to run mpd on.
  21734. @item @code{address} (default: @code{"any"})
  21735. The address that mpd will bind to. To use a Unix domain socket,
  21736. an absolute path can be specified here.
  21737. @item @code{outputs} (default: @code{"(list (mpd-output))"})
  21738. The audio outputs that MPD can use. By default this is a single output using pulseaudio.
  21739. @end table
  21740. @end deftp
  21741. @deftp {Data Type} mpd-output
  21742. Data type representing an @command{mpd} audio output.
  21743. @table @asis
  21744. @item @code{name} (default: @code{"MPD"})
  21745. The name of the audio output.
  21746. @item @code{type} (default: @code{"pulse"})
  21747. The type of audio output.
  21748. @item @code{enabled?} (default: @code{#t})
  21749. Specifies whether this audio output is enabled when MPD is started. By
  21750. default, all audio outputs are enabled. This is just the default
  21751. setting when there is no state file; with a state file, the previous
  21752. state is restored.
  21753. @item @code{tags?} (default: @code{#t})
  21754. If set to @code{#f}, then MPD will not send tags to this output. This
  21755. is only useful for output plugins that can receive tags, for example the
  21756. @code{httpd} output plugin.
  21757. @item @code{always-on?} (default: @code{#f})
  21758. If set to @code{#t}, then MPD attempts to keep this audio output always
  21759. open. This may be useful for streaming servers, when you don’t want to
  21760. disconnect all listeners even when playback is accidentally stopped.
  21761. @item @code{mixer-type}
  21762. This field accepts a symbol that specifies which mixer should be used
  21763. for this audio output: the @code{hardware} mixer, the @code{software}
  21764. mixer, the @code{null} mixer (allows setting the volume, but with no
  21765. effect; this can be used as a trick to implement an external mixer
  21766. External Mixer) or no mixer (@code{none}).
  21767. @item @code{extra-options} (default: @code{'()})
  21768. An association list of option symbols to string values to be appended to
  21769. the audio output configuration.
  21770. @end table
  21771. @end deftp
  21772. The following example shows a configuration of @code{mpd} that provides
  21773. an HTTP audio streaming output.
  21774. @lisp
  21775. (service mpd-service-type
  21776. (mpd-configuration
  21777. (outputs
  21778. (list (mpd-output
  21779. (name "streaming")
  21780. (type "httpd")
  21781. (mixer-type 'null)
  21782. (extra-options
  21783. `((encoder . "vorbis")
  21784. (port . "8080"))))))))
  21785. @end lisp
  21786. @node Virtualization Services
  21787. @subsection Virtualization Services
  21788. The @code{(gnu services virtualization)} module provides services for
  21789. the libvirt and virtlog daemons, as well as other virtualization-related
  21790. services.
  21791. @subsubheading Libvirt daemon
  21792. @code{libvirtd} is the server side daemon component of the libvirt
  21793. virtualization management system. This daemon runs on host servers
  21794. and performs required management tasks for virtualized guests.
  21795. @deffn {Scheme Variable} libvirt-service-type
  21796. This is the type of the @uref{https://libvirt.org, libvirt daemon}.
  21797. Its value must be a @code{libvirt-configuration}.
  21798. @lisp
  21799. (service libvirt-service-type
  21800. (libvirt-configuration
  21801. (unix-sock-group "libvirt")
  21802. (tls-port "16555")))
  21803. @end lisp
  21804. @end deffn
  21805. @c Auto-generated with (generate-libvirt-documentation)
  21806. Available @code{libvirt-configuration} fields are:
  21807. @deftypevr {@code{libvirt-configuration} parameter} package libvirt
  21808. Libvirt package.
  21809. @end deftypevr
  21810. @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
  21811. Flag listening for secure TLS connections on the public TCP/IP port.
  21812. You must set @code{listen} for this to have any effect.
  21813. It is necessary to setup a CA and issue server certificates before using
  21814. this capability.
  21815. Defaults to @samp{#t}.
  21816. @end deftypevr
  21817. @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
  21818. Listen for unencrypted TCP connections on the public TCP/IP port. You must
  21819. set @code{listen} for this to have any effect.
  21820. Using the TCP socket requires SASL authentication by default. Only SASL
  21821. mechanisms which support data encryption are allowed. This is
  21822. DIGEST_MD5 and GSSAPI (Kerberos5).
  21823. Defaults to @samp{#f}.
  21824. @end deftypevr
  21825. @deftypevr {@code{libvirt-configuration} parameter} string tls-port
  21826. Port for accepting secure TLS connections. This can be a port number,
  21827. or service name.
  21828. Defaults to @samp{"16514"}.
  21829. @end deftypevr
  21830. @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
  21831. Port for accepting insecure TCP connections. This can be a port number,
  21832. or service name.
  21833. Defaults to @samp{"16509"}.
  21834. @end deftypevr
  21835. @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
  21836. IP address or hostname used for client connections.
  21837. Defaults to @samp{"0.0.0.0"}.
  21838. @end deftypevr
  21839. @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
  21840. Flag toggling mDNS advertisement of the libvirt service.
  21841. Alternatively can disable for all services on a host by stopping the
  21842. Avahi daemon.
  21843. Defaults to @samp{#f}.
  21844. @end deftypevr
  21845. @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
  21846. Default mDNS advertisement name. This must be unique on the immediate
  21847. broadcast network.
  21848. Defaults to @samp{"Virtualization Host <hostname>"}.
  21849. @end deftypevr
  21850. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
  21851. UNIX domain socket group ownership. This can be used to allow a
  21852. 'trusted' set of users access to management capabilities without
  21853. becoming root.
  21854. Defaults to @samp{"root"}.
  21855. @end deftypevr
  21856. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
  21857. UNIX socket permissions for the R/O socket. This is used for monitoring
  21858. VM status only.
  21859. Defaults to @samp{"0777"}.
  21860. @end deftypevr
  21861. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
  21862. UNIX socket permissions for the R/W socket. Default allows only root.
  21863. If PolicyKit is enabled on the socket, the default will change to allow
  21864. everyone (eg, 0777)
  21865. Defaults to @samp{"0770"}.
  21866. @end deftypevr
  21867. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
  21868. UNIX socket permissions for the admin socket. Default allows only owner
  21869. (root), do not change it unless you are sure to whom you are exposing
  21870. the access to.
  21871. Defaults to @samp{"0777"}.
  21872. @end deftypevr
  21873. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
  21874. The directory in which sockets will be found/created.
  21875. Defaults to @samp{"/var/run/libvirt"}.
  21876. @end deftypevr
  21877. @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
  21878. Authentication scheme for UNIX read-only sockets. By default socket
  21879. permissions allow anyone to connect
  21880. Defaults to @samp{"polkit"}.
  21881. @end deftypevr
  21882. @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
  21883. Authentication scheme for UNIX read-write sockets. By default socket
  21884. permissions only allow root. If PolicyKit support was compiled into
  21885. libvirt, the default will be to use 'polkit' auth.
  21886. Defaults to @samp{"polkit"}.
  21887. @end deftypevr
  21888. @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
  21889. Authentication scheme for TCP sockets. If you don't enable SASL, then
  21890. all TCP traffic is cleartext. Don't do this outside of a dev/test
  21891. scenario.
  21892. Defaults to @samp{"sasl"}.
  21893. @end deftypevr
  21894. @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
  21895. Authentication scheme for TLS sockets. TLS sockets already have
  21896. encryption provided by the TLS layer, and limited authentication is done
  21897. by certificates.
  21898. It is possible to make use of any SASL authentication mechanism as well,
  21899. by using 'sasl' for this option
  21900. Defaults to @samp{"none"}.
  21901. @end deftypevr
  21902. @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
  21903. API access control scheme.
  21904. By default an authenticated user is allowed access to all APIs. Access
  21905. drivers can place restrictions on this.
  21906. Defaults to @samp{()}.
  21907. @end deftypevr
  21908. @deftypevr {@code{libvirt-configuration} parameter} string key-file
  21909. Server key file path. If set to an empty string, then no private key is
  21910. loaded.
  21911. Defaults to @samp{""}.
  21912. @end deftypevr
  21913. @deftypevr {@code{libvirt-configuration} parameter} string cert-file
  21914. Server key file path. If set to an empty string, then no certificate is
  21915. loaded.
  21916. Defaults to @samp{""}.
  21917. @end deftypevr
  21918. @deftypevr {@code{libvirt-configuration} parameter} string ca-file
  21919. Server key file path. If set to an empty string, then no CA certificate
  21920. is loaded.
  21921. Defaults to @samp{""}.
  21922. @end deftypevr
  21923. @deftypevr {@code{libvirt-configuration} parameter} string crl-file
  21924. Certificate revocation list path. If set to an empty string, then no
  21925. CRL is loaded.
  21926. Defaults to @samp{""}.
  21927. @end deftypevr
  21928. @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
  21929. Disable verification of our own server certificates.
  21930. When libvirtd starts it performs some sanity checks against its own
  21931. certificates.
  21932. Defaults to @samp{#f}.
  21933. @end deftypevr
  21934. @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
  21935. Disable verification of client certificates.
  21936. Client certificate verification is the primary authentication mechanism.
  21937. Any client which does not present a certificate signed by the CA will be
  21938. rejected.
  21939. Defaults to @samp{#f}.
  21940. @end deftypevr
  21941. @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
  21942. Whitelist of allowed x509 Distinguished Name.
  21943. Defaults to @samp{()}.
  21944. @end deftypevr
  21945. @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
  21946. Whitelist of allowed SASL usernames. The format for username depends on
  21947. the SASL authentication mechanism.
  21948. Defaults to @samp{()}.
  21949. @end deftypevr
  21950. @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
  21951. Override the compile time default TLS priority string. The default is
  21952. usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
  21953. is desired for libvirt to deviate from the global default settings.
  21954. Defaults to @samp{"NORMAL"}.
  21955. @end deftypevr
  21956. @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
  21957. Maximum number of concurrent client connections to allow over all
  21958. sockets combined.
  21959. Defaults to @samp{5000}.
  21960. @end deftypevr
  21961. @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
  21962. Maximum length of queue of connections waiting to be accepted by the
  21963. daemon. Note, that some protocols supporting retransmission may obey
  21964. this so that a later reattempt at connection succeeds.
  21965. Defaults to @samp{1000}.
  21966. @end deftypevr
  21967. @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
  21968. Maximum length of queue of accepted but not yet authenticated clients.
  21969. Set this to zero to turn this feature off
  21970. Defaults to @samp{20}.
  21971. @end deftypevr
  21972. @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
  21973. Number of workers to start up initially.
  21974. Defaults to @samp{5}.
  21975. @end deftypevr
  21976. @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
  21977. Maximum number of worker threads.
  21978. If the number of active clients exceeds @code{min-workers}, then more
  21979. threads are spawned, up to max_workers limit. Typically you'd want
  21980. max_workers to equal maximum number of clients allowed.
  21981. Defaults to @samp{20}.
  21982. @end deftypevr
  21983. @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
  21984. Number of priority workers. If all workers from above pool are stuck,
  21985. some calls marked as high priority (notably domainDestroy) can be
  21986. executed in this pool.
  21987. Defaults to @samp{5}.
  21988. @end deftypevr
  21989. @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
  21990. Total global limit on concurrent RPC calls.
  21991. Defaults to @samp{20}.
  21992. @end deftypevr
  21993. @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
  21994. Limit on concurrent requests from a single client connection. To avoid
  21995. one client monopolizing the server this should be a small fraction of
  21996. the global max_requests and max_workers parameter.
  21997. Defaults to @samp{5}.
  21998. @end deftypevr
  21999. @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
  22000. Same as @code{min-workers} but for the admin interface.
  22001. Defaults to @samp{1}.
  22002. @end deftypevr
  22003. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
  22004. Same as @code{max-workers} but for the admin interface.
  22005. Defaults to @samp{5}.
  22006. @end deftypevr
  22007. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
  22008. Same as @code{max-clients} but for the admin interface.
  22009. Defaults to @samp{5}.
  22010. @end deftypevr
  22011. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
  22012. Same as @code{max-queued-clients} but for the admin interface.
  22013. Defaults to @samp{5}.
  22014. @end deftypevr
  22015. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
  22016. Same as @code{max-client-requests} but for the admin interface.
  22017. Defaults to @samp{5}.
  22018. @end deftypevr
  22019. @deftypevr {@code{libvirt-configuration} parameter} integer log-level
  22020. Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
  22021. Defaults to @samp{3}.
  22022. @end deftypevr
  22023. @deftypevr {@code{libvirt-configuration} parameter} string log-filters
  22024. Logging filters.
  22025. A filter allows to select a different logging level for a given category
  22026. of logs. The format for a filter is one of:
  22027. @itemize @bullet
  22028. @item
  22029. x:name
  22030. @item
  22031. x:+name
  22032. @end itemize
  22033. where @code{name} is a string which is matched against the category
  22034. given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
  22035. file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
  22036. name in the filter can be a substring of the full category name, in
  22037. order to match multiple similar categories), the optional @samp{"+"}
  22038. prefix tells libvirt to log stack trace for each message matching name,
  22039. and @code{x} is the minimal level where matching messages should be
  22040. logged:
  22041. @itemize @bullet
  22042. @item
  22043. 1: DEBUG
  22044. @item
  22045. 2: INFO
  22046. @item
  22047. 3: WARNING
  22048. @item
  22049. 4: ERROR
  22050. @end itemize
  22051. Multiple filters can be defined in a single filters statement, they just
  22052. need to be separated by spaces.
  22053. Defaults to @samp{"3:remote 4:event"}.
  22054. @end deftypevr
  22055. @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
  22056. Logging outputs.
  22057. An output is one of the places to save logging information. The format
  22058. for an output can be:
  22059. @table @code
  22060. @item x:stderr
  22061. output goes to stderr
  22062. @item x:syslog:name
  22063. use syslog for the output and use the given name as the ident
  22064. @item x:file:file_path
  22065. output to a file, with the given filepath
  22066. @item x:journald
  22067. output to journald logging system
  22068. @end table
  22069. In all case the x prefix is the minimal level, acting as a filter
  22070. @itemize @bullet
  22071. @item
  22072. 1: DEBUG
  22073. @item
  22074. 2: INFO
  22075. @item
  22076. 3: WARNING
  22077. @item
  22078. 4: ERROR
  22079. @end itemize
  22080. Multiple outputs can be defined, they just need to be separated by
  22081. spaces.
  22082. Defaults to @samp{"3:stderr"}.
  22083. @end deftypevr
  22084. @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
  22085. Allows usage of the auditing subsystem to be altered
  22086. @itemize @bullet
  22087. @item
  22088. 0: disable all auditing
  22089. @item
  22090. 1: enable auditing, only if enabled on host
  22091. @item
  22092. 2: enable auditing, and exit if disabled on host.
  22093. @end itemize
  22094. Defaults to @samp{1}.
  22095. @end deftypevr
  22096. @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
  22097. Send audit messages via libvirt logging infrastructure.
  22098. Defaults to @samp{#f}.
  22099. @end deftypevr
  22100. @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
  22101. Host UUID@. UUID must not have all digits be the same.
  22102. Defaults to @samp{""}.
  22103. @end deftypevr
  22104. @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
  22105. Source to read host UUID.
  22106. @itemize @bullet
  22107. @item
  22108. @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
  22109. @item
  22110. @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
  22111. @end itemize
  22112. If @code{dmidecode} does not provide a valid UUID a temporary UUID will
  22113. be generated.
  22114. Defaults to @samp{"smbios"}.
  22115. @end deftypevr
  22116. @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
  22117. A keepalive message is sent to a client after @code{keepalive_interval}
  22118. seconds of inactivity to check if the client is still responding. If
  22119. set to -1, libvirtd will never send keepalive requests; however clients
  22120. can still send them and the daemon will send responses.
  22121. Defaults to @samp{5}.
  22122. @end deftypevr
  22123. @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
  22124. Maximum number of keepalive messages that are allowed to be sent to the
  22125. client without getting any response before the connection is considered
  22126. broken.
  22127. In other words, the connection is automatically closed approximately
  22128. after @code{keepalive_interval * (keepalive_count + 1)} seconds since
  22129. the last message received from the client. When @code{keepalive-count}
  22130. is set to 0, connections will be automatically closed after
  22131. @code{keepalive-interval} seconds of inactivity without sending any
  22132. keepalive messages.
  22133. Defaults to @samp{5}.
  22134. @end deftypevr
  22135. @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
  22136. Same as above but for admin interface.
  22137. Defaults to @samp{5}.
  22138. @end deftypevr
  22139. @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
  22140. Same as above but for admin interface.
  22141. Defaults to @samp{5}.
  22142. @end deftypevr
  22143. @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
  22144. Timeout for Open vSwitch calls.
  22145. The @code{ovs-vsctl} utility is used for the configuration and its
  22146. timeout option is set by default to 5 seconds to avoid potential
  22147. infinite waits blocking libvirt.
  22148. Defaults to @samp{5}.
  22149. @end deftypevr
  22150. @c %end of autogenerated docs
  22151. @subsubheading Virtlog daemon
  22152. The virtlogd service is a server side daemon component of libvirt that is
  22153. used to manage logs from virtual machine consoles.
  22154. This daemon is not used directly by libvirt client applications, rather it
  22155. is called on their behalf by @code{libvirtd}. By maintaining the logs in a
  22156. standalone daemon, the main @code{libvirtd} daemon can be restarted without
  22157. risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
  22158. itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
  22159. @deffn {Scheme Variable} virtlog-service-type
  22160. This is the type of the virtlog daemon.
  22161. Its value must be a @code{virtlog-configuration}.
  22162. @lisp
  22163. (service virtlog-service-type
  22164. (virtlog-configuration
  22165. (max-clients 1000)))
  22166. @end lisp
  22167. @end deffn
  22168. @deftypevr {@code{virtlog-configuration} parameter} integer log-level
  22169. Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
  22170. Defaults to @samp{3}.
  22171. @end deftypevr
  22172. @deftypevr {@code{virtlog-configuration} parameter} string log-filters
  22173. Logging filters.
  22174. A filter allows to select a different logging level for a given category
  22175. of logs The format for a filter is one of:
  22176. @itemize @bullet
  22177. @item
  22178. x:name
  22179. @item
  22180. x:+name
  22181. @end itemize
  22182. where @code{name} is a string which is matched against the category
  22183. given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
  22184. file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
  22185. be a substring of the full category name, in order to match multiple
  22186. similar categories), the optional "+" prefix tells libvirt to log stack
  22187. trace for each message matching name, and @code{x} is the minimal level
  22188. where matching messages should be logged:
  22189. @itemize @bullet
  22190. @item
  22191. 1: DEBUG
  22192. @item
  22193. 2: INFO
  22194. @item
  22195. 3: WARNING
  22196. @item
  22197. 4: ERROR
  22198. @end itemize
  22199. Multiple filters can be defined in a single filters statement, they just
  22200. need to be separated by spaces.
  22201. Defaults to @samp{"3:remote 4:event"}.
  22202. @end deftypevr
  22203. @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
  22204. Logging outputs.
  22205. An output is one of the places to save logging information The format
  22206. for an output can be:
  22207. @table @code
  22208. @item x:stderr
  22209. output goes to stderr
  22210. @item x:syslog:name
  22211. use syslog for the output and use the given name as the ident
  22212. @item x:file:file_path
  22213. output to a file, with the given filepath
  22214. @item x:journald
  22215. output to journald logging system
  22216. @end table
  22217. In all case the x prefix is the minimal level, acting as a filter
  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 outputs can be defined, they just need to be separated by
  22229. spaces.
  22230. Defaults to @samp{"3:stderr"}.
  22231. @end deftypevr
  22232. @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
  22233. Maximum number of concurrent client connections to allow over all
  22234. sockets combined.
  22235. Defaults to @samp{1024}.
  22236. @end deftypevr
  22237. @deftypevr {@code{virtlog-configuration} parameter} integer max-size
  22238. Maximum file size before rolling over.
  22239. Defaults to @samp{2MB}
  22240. @end deftypevr
  22241. @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
  22242. Maximum number of backup files to keep.
  22243. Defaults to @samp{3}
  22244. @end deftypevr
  22245. @anchor{transparent-emulation-qemu}
  22246. @subsubheading Transparent Emulation with QEMU
  22247. @cindex emulation
  22248. @cindex @code{binfmt_misc}
  22249. @code{qemu-binfmt-service-type} provides support for transparent
  22250. emulation of program binaries built for different architectures---e.g.,
  22251. it allows you to transparently execute an ARMv7 program on an x86_64
  22252. machine. It achieves this by combining the @uref{https://www.qemu.org,
  22253. QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
  22254. This feature only allows you to emulate GNU/Linux on a different
  22255. architecture, but see below for GNU/Hurd support.
  22256. @defvr {Scheme Variable} qemu-binfmt-service-type
  22257. This is the type of the QEMU/binfmt service for transparent emulation.
  22258. Its value must be a @code{qemu-binfmt-configuration} object, which
  22259. specifies the QEMU package to use as well as the architecture we want to
  22260. emulated:
  22261. @lisp
  22262. (service qemu-binfmt-service-type
  22263. (qemu-binfmt-configuration
  22264. (platforms (lookup-qemu-platforms "arm" "aarch64"))))
  22265. @end lisp
  22266. In this example, we enable transparent emulation for the ARM and aarch64
  22267. platforms. Running @code{herd stop qemu-binfmt} turns it off, and
  22268. running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
  22269. herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
  22270. @end defvr
  22271. @deftp {Data Type} qemu-binfmt-configuration
  22272. This is the configuration for the @code{qemu-binfmt} service.
  22273. @table @asis
  22274. @item @code{platforms} (default: @code{'()})
  22275. The list of emulated QEMU platforms. Each item must be a @dfn{platform
  22276. object} as returned by @code{lookup-qemu-platforms} (see below).
  22277. @item @code{guix-support?} (default: @code{#t})
  22278. When it is true, QEMU and all its dependencies are added to the build
  22279. environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
  22280. @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
  22281. handlers to be used within the build environment, which in turn means
  22282. that you can transparently build programs for another architecture.
  22283. For example, let's suppose you're on an x86_64 machine and you have this
  22284. service:
  22285. @lisp
  22286. (service qemu-binfmt-service-type
  22287. (qemu-binfmt-configuration
  22288. (platforms (lookup-qemu-platforms "arm"))
  22289. (guix-support? #t)))
  22290. @end lisp
  22291. You can run:
  22292. @example
  22293. guix build -s armhf-linux inkscape
  22294. @end example
  22295. @noindent
  22296. and it will build Inkscape for ARMv7 @emph{as if it were a native
  22297. build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
  22298. if you'd like to test a package build for an architecture you don't have
  22299. access to!
  22300. When @code{guix-support?} is set to @code{#f}, programs for other
  22301. architectures can still be executed transparently, but invoking commands
  22302. like @command{guix build -s armhf-linux @dots{}} will fail.
  22303. @item @code{qemu} (default: @code{qemu})
  22304. The QEMU package to use.
  22305. @end table
  22306. @end deftp
  22307. @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
  22308. Return the list of QEMU platform objects corresponding to
  22309. @var{platforms}@dots{}. @var{platforms} must be a list of strings
  22310. corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
  22311. @code{"mips64el"}, and so on.
  22312. @end deffn
  22313. @deffn {Scheme Procedure} qemu-platform? @var{obj}
  22314. Return true if @var{obj} is a platform object.
  22315. @end deffn
  22316. @deffn {Scheme Procedure} qemu-platform-name @var{platform}
  22317. Return the name of @var{platform}---a string such as @code{"arm"}.
  22318. @end deffn
  22319. @subsubheading The Hurd in a Virtual Machine
  22320. @cindex @code{hurd}
  22321. @cindex the Hurd
  22322. @cindex childhurd
  22323. Service @code{hurd-vm} provides support for running GNU/Hurd in a
  22324. virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
  22325. to be used on GNU/Linux and the given GNU/Hurd operating system
  22326. configuration is cross-compiled. The virtual machine is a Shepherd
  22327. service that can be referred to by the names @code{hurd-vm} and
  22328. @code{childhurd} and be controlled with commands such as:
  22329. @example
  22330. herd start hurd-vm
  22331. herd stop childhurd
  22332. @end example
  22333. When the service is running, you can view its console by connecting to
  22334. it with a VNC client, for example with:
  22335. @example
  22336. guix environment --ad-hoc tigervnc-client -- \
  22337. vncviewer localhost:5900
  22338. @end example
  22339. The default configuration (see @code{hurd-vm-configuration} below)
  22340. spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
  22341. (the virtual machine emulator) redirects to port 10222 on the host.
  22342. Thus, you can connect over SSH to the childhurd with:
  22343. @example
  22344. ssh root@@localhost -p 10022
  22345. @end example
  22346. The childhurd is volatile and stateless: it starts with a fresh root
  22347. file system every time you restart it. By default though, all the files
  22348. under @file{/etc/childhurd} on the host are copied as is to the root
  22349. file system of the childhurd when it boots. This allows you to
  22350. initialize ``secrets'' inside the VM: SSH host keys, authorized
  22351. substitute keys, and so on---see the explanation of @code{secret-root}
  22352. below.
  22353. @defvr {Scheme Variable} hurd-vm-service-type
  22354. This is the type of the Hurd in a Virtual Machine service. Its value
  22355. must be a @code{hurd-vm-configuration} object, which specifies the
  22356. operating system (@pxref{operating-system Reference}) and the disk size
  22357. for the Hurd Virtual Machine, the QEMU package to use as well as the
  22358. options for running it.
  22359. For example:
  22360. @lisp
  22361. (service hurd-vm-service-type
  22362. (hurd-vm-configuration
  22363. (disk-size (* 5000 (expt 2 20))) ;5G
  22364. (memory-size 1024))) ;1024MiB
  22365. @end lisp
  22366. would create a disk image big enough to build GNU@tie{}Hello, with some
  22367. extra memory.
  22368. @end defvr
  22369. @deftp {Data Type} hurd-vm-configuration
  22370. The data type representing the configuration for
  22371. @code{hurd-vm-service-type}.
  22372. @table @asis
  22373. @item @code{os} (default: @var{%hurd-vm-operating-system})
  22374. The operating system to instantiate. This default is bare-bones with a
  22375. permissive OpenSSH secure shell daemon listening on port 2222
  22376. (@pxref{Networking Services, @code{openssh-service-type}}).
  22377. @item @code{qemu} (default: @code{qemu-minimal})
  22378. The QEMU package to use.
  22379. @item @code{image} (default: @var{hurd-vm-disk-image})
  22380. The procedure used to build the disk-image built from this
  22381. configuration.
  22382. @item @code{disk-size} (default: @code{'guess})
  22383. The size of the disk image.
  22384. @item @code{memory-size} (default: @code{512})
  22385. The memory size of the Virtual Machine in mebibytes.
  22386. @item @code{options} (default: @code{'("--snapshot")})
  22387. The extra options for running QEMU.
  22388. @item @code{id} (default: @code{#f})
  22389. If set, a non-zero positive integer used to parameterize Childhurd
  22390. instances. It is appended to the service's name,
  22391. e.g. @code{childhurd1}.
  22392. @item @code{net-options} (default: @var{hurd-vm-net-options})
  22393. The procedure used to produce the list of QEMU networking options.
  22394. By default, it produces
  22395. @lisp
  22396. '("--device" "rtl8139,netdev=net0"
  22397. "--netdev" "user,id=net0\
  22398. ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
  22399. ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
  22400. ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
  22401. @end lisp
  22402. with forwarded ports:
  22403. @example
  22404. @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
  22405. @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
  22406. @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
  22407. @end example
  22408. @item @code{secret-root} (default: @file{/etc/childhurd})
  22409. The root directory with out-of-band secrets to be installed into the
  22410. childhurd once it runs. Childhurds are volatile which means that on
  22411. every startup, secrets such as the SSH host keys and Guix signing key
  22412. are recreated.
  22413. If the @file{/etc/childhurd} directory does not exist, the
  22414. @code{secret-service} running in the Childhurd will be sent an empty
  22415. list of secrets.
  22416. By default, the service automatically populates @file{/etc/childhurd}
  22417. with the following non-volatile secrets, unless they already exist:
  22418. @example
  22419. /etc/childhurd/etc/guix/acl
  22420. /etc/childhurd/etc/guix/signing-key.pub
  22421. /etc/childhurd/etc/guix/signing-key.sec
  22422. /etc/childhurd/etc/ssh/ssh_host_ed25519_key
  22423. /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
  22424. /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
  22425. /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
  22426. @end example
  22427. These files are automatically sent to the guest Hurd VM when it boots,
  22428. including permissions.
  22429. @cindex childhurd, offloading
  22430. @cindex Hurd, offloading
  22431. Having these files in place means that only a couple of things are
  22432. missing to allow the host to offload @code{i586-gnu} builds to the
  22433. childhurd:
  22434. @enumerate
  22435. @item
  22436. Authorizing the childhurd's key on the host so that the host accepts
  22437. build results coming from the childhurd, which can be done like so:
  22438. @example
  22439. guix archive --authorize < \
  22440. /etc/childhurd/etc/guix/signing-key.pub
  22441. @end example
  22442. @item
  22443. Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
  22444. Offload Setup}).
  22445. @end enumerate
  22446. We're working towards making that happen automatically---get in touch
  22447. with us at @email{guix-devel@@gnu.org} to discuss it!
  22448. @end table
  22449. @end deftp
  22450. Note that by default the VM image is volatile, i.e., once stopped the
  22451. contents are lost. If you want a stateful image instead, override the
  22452. configuration's @code{image} and @code{options} without
  22453. the @code{--snapshot} flag using something along these lines:
  22454. @lisp
  22455. (service hurd-vm-service-type
  22456. (hurd-vm-configuration
  22457. (image (const "/out/of/store/writable/hurd.img"))
  22458. (options '())))
  22459. @end lisp
  22460. @subsubheading Ganeti
  22461. @cindex ganeti
  22462. @quotation Note
  22463. This service is considered experimental. Configuration options may be changed
  22464. in a backwards-incompatible manner, and not all features have been thorougly
  22465. tested. Users of this service are encouraged to share their experience at
  22466. @email{guix-devel@@gnu.org}.
  22467. @end quotation
  22468. Ganeti is a virtual machine management system. It is designed to keep virtual
  22469. machines running on a cluster of servers even in the event of hardware failures,
  22470. and to make maintenance and recovery tasks easy. It consists of multiple
  22471. services which are described later in this section. In addition to the Ganeti
  22472. service, you will need the OpenSSH service (@pxref{Networking Services,
  22473. @code{openssh-service-type}}), and update the @file{/etc/hosts} file
  22474. (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
  22475. and address (or use a DNS server).
  22476. All nodes participating in a Ganeti cluster should have the same Ganeti and
  22477. @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
  22478. cluster node that supports multiple storage backends, and installs the
  22479. @code{debootstrap} and @code{guix} @dfn{OS providers}:
  22480. @lisp
  22481. (use-package-modules virtualization)
  22482. (use-service-modules base ganeti networking ssh)
  22483. (operating-system
  22484. ;; @dots{}
  22485. (host-name "node1")
  22486. (hosts-file (plain-file "hosts" (format #f "
  22487. 127.0.0.1 localhost
  22488. ::1 localhost
  22489. 192.168.1.200 ganeti.example.com
  22490. 192.168.1.201 node1.example.com node1
  22491. 192.168.1.202 node2.example.com node2
  22492. ")))
  22493. ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
  22494. ;; in order to use the "plain", "drbd" and "rbd" storage backends.
  22495. (packages (append (map specification->package
  22496. '("qemu" "lvm2" "drbd-utils" "ceph"
  22497. ;; Add the debootstrap and guix OS providers.
  22498. "ganeti-instance-guix" "ganeti-instance-debootstrap"))
  22499. %base-packages))
  22500. (services
  22501. (append (list (static-networking-service "eth0" "192.168.1.201"
  22502. #:netmask "255.255.255.0"
  22503. #:gateway "192.168.1.254"
  22504. #:name-servers '("192.168.1.252"
  22505. "192.168.1.253"))
  22506. ;; Ganeti uses SSH to communicate between nodes.
  22507. (service openssh-service-type
  22508. (openssh-configuration
  22509. (permit-root-login 'without-password)))
  22510. (service ganeti-service-type
  22511. (ganeti-configuration
  22512. ;; This list specifies allowed file system paths
  22513. ;; for storing virtual machine images.
  22514. (file-storage-paths '("/srv/ganeti/file-storage"))
  22515. ;; This variable configures a single "variant" for
  22516. ;; both Debootstrap and Guix that works with KVM.
  22517. (os %default-ganeti-os))))
  22518. %base-services)))
  22519. @end lisp
  22520. Users are advised to read the
  22521. @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
  22522. administrators guide} to learn about the various cluster options and
  22523. day-to-day operations. There is also a
  22524. @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
  22525. describing how to configure and initialize a small cluster.
  22526. @defvr {Scheme Variable} ganeti-service-type
  22527. This is a service type that includes all the various services that Ganeti
  22528. nodes should run.
  22529. Its value is a @code{ganeti-configuration} object that defines the package
  22530. to use for CLI operations, as well as configuration for the various daemons.
  22531. Allowed file storage paths and available guest operating systems are also
  22532. configured through this data type.
  22533. @end defvr
  22534. @deftp {Data Type} ganeti-configuration
  22535. The @code{ganeti} service takes the following configuration options:
  22536. @table @asis
  22537. @item @code{ganeti} (default: @code{ganeti})
  22538. The @code{ganeti} package to use. It will be installed to the system profile
  22539. and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
  22540. that the value specified here does not affect the other services as each refer
  22541. to a specific @code{ganeti} package (see below).
  22542. @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
  22543. @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
  22544. @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
  22545. @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
  22546. @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
  22547. @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
  22548. @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
  22549. @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
  22550. @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
  22551. @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
  22552. These options control the various daemons and cron jobs that are distributed
  22553. with Ganeti. The possible values for these are described in detail below.
  22554. To override a setting, you must use the configuration type for that service:
  22555. @lisp
  22556. (service ganeti-service-type
  22557. (ganeti-configuration
  22558. (rapi-configuration
  22559. (ganeti-rapi-configuration
  22560. (interface "eth1"))))
  22561. (watcher-configuration
  22562. (ganeti-watcher-configuration
  22563. (rapi-ip "10.0.0.1"))))
  22564. @end lisp
  22565. @item @code{file-storage-paths} (default: @code{'()})
  22566. List of allowed directories for file storage backend.
  22567. @item @code{os} (default: @code{%default-ganeti-os})
  22568. List of @code{<ganeti-os>} records.
  22569. @end table
  22570. In essence @code{ganeti-service-type} is shorthand for declaring each service
  22571. individually:
  22572. @lisp
  22573. (service ganeti-noded-service-type)
  22574. (service ganeti-confd-service-type)
  22575. (service ganeti-wconfd-service-type)
  22576. (service ganeti-luxid-service-type)
  22577. (service ganeti-kvmd-service-type)
  22578. (service ganeti-mond-service-type)
  22579. (service ganeti-metad-service-type)
  22580. (service ganeti-watcher-service-type)
  22581. (service ganeti-cleaner-service-type)
  22582. @end lisp
  22583. Plus a service extension for @code{etc-service-type} that configures the file
  22584. storage backend and OS variants.
  22585. @end deftp
  22586. @deftp {Data Type} ganeti-os
  22587. This data type is suitable for passing to the @code{os} parameter of
  22588. @code{ganeti-configuration}. It takes the following parameters:
  22589. @table @asis
  22590. @item @code{name}
  22591. The name for this OS provider. It is only used to specify where the
  22592. configuration ends up. Setting it to ``debootstrap'' will create
  22593. @file{/etc/ganeti/instance-debootstrap}.
  22594. @item @code{extension}
  22595. The file extension for variants of this OS type. For example
  22596. @file{.conf} or @file{.scm}.
  22597. @item @code{variants} (default: @code{'()})
  22598. List of @code{ganeti-os-variant} objects for this OS.
  22599. @end table
  22600. @end deftp
  22601. @deftp {Data Type} ganeti-os-variant
  22602. This is the data type for a Ganeti OS variant. It takes the following
  22603. parameters:
  22604. @table @asis
  22605. @item @code{name}
  22606. The name of this variant.
  22607. @item @code{configuration}
  22608. A configuration file for this variant.
  22609. @end table
  22610. @end deftp
  22611. @defvr {Scheme Variable} %default-debootstrap-hooks
  22612. This variable contains hooks to configure networking and the GRUB bootloader.
  22613. @end defvr
  22614. @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
  22615. This variable contains a list of packages suitable for a fully-virtualized guest.
  22616. @end defvr
  22617. @deftp {Data Type} debootstrap-configuration
  22618. This data type creates configuration files suitable for the debootstrap OS provider.
  22619. @table @asis
  22620. @item @code{hooks} (default: @code{%default-debootstrap-hooks})
  22621. When not @code{#f}, this must be a G-expression that specifies a directory with
  22622. scripts that will run when the OS is installed. It can also be a list of
  22623. @code{(name . file-like)} pairs. For example:
  22624. @lisp
  22625. `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
  22626. @end lisp
  22627. That will create a directory with one executable named @code{99-hello-world}
  22628. and run it every time this variant is installed. If set to @code{#f}, hooks
  22629. in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
  22630. @item @code{proxy} (default: @code{#f})
  22631. Optional HTTP proxy to use.
  22632. @item @code{mirror} (default: @code{#f})
  22633. The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
  22634. The default varies depending on the distribution.
  22635. @item @code{arch} (default: @code{#f})
  22636. The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
  22637. on an AArch64 host. Default is to use the current system architecture.
  22638. @item @code{suite} (default: @code{"stable"})
  22639. When set, this must be a Debian distribution ``suite'' such as @code{buster}
  22640. or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
  22641. @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
  22642. List of extra packages that will get installed by dpkg in addition
  22643. to the minimal system.
  22644. @item @code{components} (default: @code{#f})
  22645. When set, must be a list of Debian repository ``components''. For example
  22646. @code{'("main" "contrib")}.
  22647. @item @code{generate-cache?} (default: @code{#t})
  22648. Whether to automatically cache the generated debootstrap archive.
  22649. @item @code{clean-cache} (default: @code{14})
  22650. Discard the cache after this amount of days. Use @code{#f} to never
  22651. clear the cache.
  22652. @item @code{partition-style} (default: @code{'msdos})
  22653. The type of partition to create. When set, it must be one of
  22654. @code{'msdos}, @code{'none} or a string.
  22655. @item @code{partition-alignment} (default: @code{2048})
  22656. Alignment of the partition in sectors.
  22657. @end table
  22658. @end deftp
  22659. @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
  22660. This is a helper procedure that creates a @code{ganeti-os-variant} record. It
  22661. takes two parameters: a name and a @code{debootstrap-configuration} object.
  22662. @end deffn
  22663. @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
  22664. This is a helper procedure that creates a @code{ganeti-os} record. It takes
  22665. a list of variants created with @code{debootstrap-variant}.
  22666. @end deffn
  22667. @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
  22668. This is a helper procedure that creates a @code{ganeti-os-variant} record for
  22669. use with the Guix OS provider. It takes a name and a G-expression that returns
  22670. a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
  22671. Guix System configuration.
  22672. @end deffn
  22673. @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
  22674. This is a helper procedure that creates a @code{ganeti-os} record. It
  22675. takes a list of variants produced by @code{guix-variant}.
  22676. @end deffn
  22677. @defvr {Scheme Variable} %default-debootstrap-variants
  22678. This is a convenience variable to make the debootstrap provider work
  22679. ``out of the box'' without users having to declare variants manually. It
  22680. contains a single debootstrap variant with the default configuration:
  22681. @lisp
  22682. (list (debootstrap-variant
  22683. "default"
  22684. (debootstrap-configuration)))
  22685. @end lisp
  22686. @end defvr
  22687. @defvr {Scheme Variable} %default-guix-variants
  22688. This is a convenience variable to make the Guix OS provider work without
  22689. additional configuration. It creates a virtual machine that has an SSH
  22690. server, a serial console, and authorizes the Ganeti hosts SSH keys.
  22691. @lisp
  22692. (list (guix-variant
  22693. "default"
  22694. (file-append ganeti-instance-guix
  22695. "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
  22696. @end lisp
  22697. @end defvr
  22698. Users can implement support for OS providers unbeknownst to Guix by extending
  22699. the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
  22700. For example:
  22701. @lisp
  22702. (ganeti-os
  22703. (name "custom")
  22704. (extension ".conf")
  22705. (variants
  22706. (list (ganeti-os-variant
  22707. (name "foo")
  22708. (configuration (plain-file "bar" "this is fine"))))))
  22709. @end lisp
  22710. That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
  22711. to a file in the store with contents @code{this is fine}. It also creates
  22712. @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
  22713. Obviously this may not work for all OS providers out there. If you find the
  22714. interface limiting, please reach out to @email{guix-devel@@gnu.org}.
  22715. The rest of this section documents the various services that are included by
  22716. @code{ganeti-service-type}.
  22717. @defvr {Scheme Variable} ganeti-noded-service-type
  22718. @command{ganeti-noded} is the daemon responsible for node-specific functions
  22719. within the Ganeti system. The value of this service must be a
  22720. @code{ganeti-noded-configuration} object.
  22721. @end defvr
  22722. @deftp {Data Type} ganeti-noded-configuration
  22723. This is the configuration for the @code{ganeti-noded} service.
  22724. @table @asis
  22725. @item @code{ganeti} (default: @code{ganeti})
  22726. The @code{ganeti} package to use for this service.
  22727. @item @code{port} (default: @code{1811})
  22728. The TCP port on which the node daemon listens for network requests.
  22729. @item @code{address} (default: @code{"0.0.0.0"})
  22730. The network address that the daemon will bind to. The default address means
  22731. bind to all available addresses.
  22732. @item @code{interface} (default: @code{#f})
  22733. When this is set, it must be a specific network interface (e.g.@: @code{eth0})
  22734. that the daemon will bind to.
  22735. @item @code{max-clients} (default: @code{20})
  22736. This sets a limit on the maximum number of simultaneous client connections
  22737. that the daemon will handle. Connections above this count are accepted, but
  22738. no responses will be sent until enough connections have closed.
  22739. @item @code{ssl?} (default: @code{#t})
  22740. Whether to use SSL/TLS to encrypt network communications. The certificate
  22741. is automatically provisioned by the cluster and can be rotated with
  22742. @command{gnt-cluster renew-crypto}.
  22743. @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
  22744. This can be used to provide a specific encryption key for TLS communications.
  22745. @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
  22746. This can be used to provide a specific certificate for TLS communications.
  22747. @item @code{debug?} (default: @code{#f})
  22748. When true, the daemon performs additional logging for debugging purposes.
  22749. Note that this will leak encryption details to the log files, use with caution.
  22750. @end table
  22751. @end deftp
  22752. @defvr {Scheme Variable} ganeti-confd-service-type
  22753. @command{ganeti-confd} answers queries related to the configuration of a
  22754. Ganeti cluster. The purpose of this daemon is to have a highly available
  22755. and fast way to query cluster configuration values. It is automatically
  22756. active on all @dfn{master candidates}. The value of this service must be a
  22757. @code{ganeti-confd-configuration} object.
  22758. @end defvr
  22759. @deftp {Data Type} ganeti-confd-configuration
  22760. This is the configuration for the @code{ganeti-confd} service.
  22761. @table @asis
  22762. @item @code{ganeti} (default: @code{ganeti})
  22763. The @code{ganeti} package to use for this service.
  22764. @item @code{port} (default: @code{1814})
  22765. The UDP port on which to listen for network requests.
  22766. @item @code{address} (default: @code{"0.0.0.0"})
  22767. Network address that the daemon will bind to.
  22768. @item @code{debug?} (default: @code{#f})
  22769. When true, the daemon performs additional logging for debugging purposes.
  22770. @end table
  22771. @end deftp
  22772. @defvr {Scheme Variable} ganeti-wconfd-service-type
  22773. @command{ganeti-wconfd} is the daemon that has authoritative knowledge
  22774. about the cluster configuration and is the only entity that can accept
  22775. changes to it. All jobs that need to modify the configuration will do so
  22776. by sending appropriate requests to this daemon. It only runs on the
  22777. @dfn{master node} and will automatically disable itself on other nodes.
  22778. The value of this service must be a
  22779. @code{ganeti-wconfd-configuration} object.
  22780. @end defvr
  22781. @deftp {Data Type} ganeti-wconfd-configuration
  22782. This is the configuration for the @code{ganeti-wconfd} service.
  22783. @table @asis
  22784. @item @code{ganeti} (default: @code{ganeti})
  22785. The @code{ganeti} package to use for this service.
  22786. @item @code{no-voting?} (default: @code{#f})
  22787. The daemon will refuse to start if the majority of cluster nodes does not
  22788. agree that it is running on the master node. Set to @code{#t} to start
  22789. even if a quorum can not be reached (dangerous, use with caution).
  22790. @item @code{debug?} (default: @code{#f})
  22791. When true, the daemon performs additional logging for debugging purposes.
  22792. @end table
  22793. @end deftp
  22794. @defvr {Scheme Variable} ganeti-luxid-service-type
  22795. @command{ganeti-luxid} is a daemon used to answer queries related to the
  22796. configuration and the current live state of a Ganeti cluster. Additionally,
  22797. it is the authoritative daemon for the Ganeti job queue. Jobs can be
  22798. submitted via this daemon and it schedules and starts them.
  22799. It takes a @code{ganeti-luxid-configuration} object.
  22800. @end defvr
  22801. @deftp {Data Type} ganeti-luxid-configuration
  22802. This is the configuration for the @code{ganeti-wconfd} service.
  22803. @table @asis
  22804. @item @code{ganeti} (default: @code{ganeti})
  22805. The @code{ganeti} package to use for this service.
  22806. @item @code{no-voting?} (default: @code{#f})
  22807. The daemon will refuse to start if it cannot verify that the majority of
  22808. cluster nodes believes that it is running on the master node. Set to
  22809. @code{#t} to ignore such checks and start anyway (this can be dangerous).
  22810. @item @code{debug?} (default: @code{#f})
  22811. When true, the daemon performs additional logging for debugging purposes.
  22812. @end table
  22813. @end deftp
  22814. @defvr {Scheme Variable} ganeti-rapi-service-type
  22815. @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
  22816. the master node and can be used to perform cluster actions programmatically
  22817. via a JSON-based RPC protocol.
  22818. Most query operations are allowed without authentication (unless
  22819. @var{require-authentication?} is set), whereas write operations require
  22820. explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
  22821. the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
  22822. API documentation} for more information.
  22823. The value of this service must be a @code{ganeti-rapi-configuration} object.
  22824. @end defvr
  22825. @deftp {Data Type} ganeti-rapi-configuration
  22826. This is the configuration for the @code{ganeti-rapi} service.
  22827. @table @asis
  22828. @item @code{ganeti} (default: @code{ganeti})
  22829. The @code{ganeti} package to use for this service.
  22830. @item @code{require-authentication?} (default: @code{#f})
  22831. Whether to require authentication even for read-only operations.
  22832. @item @code{port} (default: @code{5080})
  22833. The TCP port on which to listen to API requests.
  22834. @item @code{address} (default: @code{"0.0.0.0"})
  22835. The network address that the service will bind to. By default it listens
  22836. on all configured addresses.
  22837. @item @code{interface} (default: @code{#f})
  22838. When set, it must specify a specific network interface such as @code{eth0}
  22839. that the daemon will bind to.
  22840. @item @code{max-clients} (default: @code{20})
  22841. The maximum number of simultaneous client requests to handle. Further
  22842. connections are allowed, but no responses are sent until enough connections
  22843. have closed.
  22844. @item @code{ssl?} (default: @code{#t})
  22845. Whether to use SSL/TLS encryption on the RAPI port.
  22846. @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
  22847. This can be used to provide a specific encryption key for TLS communications.
  22848. @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
  22849. This can be used to provide a specific certificate for TLS communications.
  22850. @item @code{debug?} (default: @code{#f})
  22851. When true, the daemon performs additional logging for debugging purposes.
  22852. Note that this will leak encryption details to the log files, use with caution.
  22853. @end table
  22854. @end deftp
  22855. @defvr {Scheme Variable} ganeti-kvmd-service-type
  22856. @command{ganeti-kvmd} is responsible for determining whether a given KVM
  22857. instance was shut down by an administrator or a user. Normally Ganeti will
  22858. restart an instance that was not stopped through Ganeti itself. If the
  22859. cluster option @code{user_shutdown} is true, this daemon monitors the
  22860. @code{QMP} socket provided by QEMU and listens for shutdown events, and
  22861. marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
  22862. it shuts down gracefully by itself.
  22863. It takes a @code{ganeti-kvmd-configuration} object.
  22864. @end defvr
  22865. @deftp {Data Type} ganeti-kvmd-configuration
  22866. @table @asis
  22867. @item @code{ganeti} (default: @code{ganeti})
  22868. The @code{ganeti} package to use for this service.
  22869. @item @code{debug?} (default: @code{#f})
  22870. When true, the daemon performs additional logging for debugging purposes.
  22871. @end table
  22872. @end deftp
  22873. @defvr {Scheme Variable} ganeti-mond-service-type
  22874. @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
  22875. functionality. It is responsible for running data collectors and publish the
  22876. collected information through a HTTP interface.
  22877. It takes a @code{ganeti-mond-configuration} object.
  22878. @end defvr
  22879. @deftp {Data Type} ganeti-mond-configuration
  22880. @table @asis
  22881. @item @code{ganeti} (default: @code{ganeti})
  22882. The @code{ganeti} package to use for this service.
  22883. @item @code{port} (default: @code{1815})
  22884. The port on which the daemon will listen.
  22885. @item @code{address} (default: @code{"0.0.0.0"})
  22886. The network address that the daemon will bind to. By default it binds to all
  22887. available interfaces.
  22888. @item @code{debug?} (default: @code{#f})
  22889. When true, the daemon performs additional logging for debugging purposes.
  22890. @end table
  22891. @end deftp
  22892. @defvr {Scheme Variable} ganeti-metad-service-type
  22893. @command{ganeti-metad} is an optional daemon that can be used to provide
  22894. information about the cluster to instances or OS install scripts.
  22895. It takes a @code{ganeti-metad-configuration} object.
  22896. @end defvr
  22897. @deftp {Data Type} ganeti-metad-configuration
  22898. @table @asis
  22899. @item @code{ganeti} (default: @code{ganeti})
  22900. The @code{ganeti} package to use for this service.
  22901. @item @code{port} (default: @code{80})
  22902. The port on which the daemon will listen.
  22903. @item @code{address} (default: @code{#f})
  22904. If set, the daemon will bind to this address only. If left unset, the behavior
  22905. depends on the cluster configuration.
  22906. @item @code{debug?} (default: @code{#f})
  22907. When true, the daemon performs additional logging for debugging purposes.
  22908. @end table
  22909. @end deftp
  22910. @defvr {Scheme Variable} ganeti-watcher-service-type
  22911. @command{ganeti-watcher} is a script designed to run periodically and ensure
  22912. the health of a cluster. It will automatically restart instances that have
  22913. stopped without Ganeti's consent, and repairs DRBD links in case a node has
  22914. rebooted. It also archives old cluster jobs and restarts Ganeti daemons
  22915. that are not running. If the cluster parameter @code{ensure_node_health}
  22916. is set, the watcher will also shutdown instances and DRBD devices if the
  22917. node it is running on is declared offline by known master candidates.
  22918. It can be paused on all nodes with @command{gnt-cluster watcher pause}.
  22919. The service takes a @code{ganeti-watcher-configuration} object.
  22920. @end defvr
  22921. @deftp {Data Type} ganeti-watcher-configuration
  22922. @table @asis
  22923. @item @code{ganeti} (default: @code{ganeti})
  22924. The @code{ganeti} package to use for this service.
  22925. @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
  22926. How often to run the script. The default is every five minutes.
  22927. @item @code{rapi-ip} (default: @code{#f})
  22928. This option needs to be specified only if the RAPI daemon is configured to use
  22929. a particular interface or address. By default the cluster address is used.
  22930. @item @code{job-age} (default: @code{(* 6 3600)})
  22931. Archive cluster jobs older than this age, specified in seconds. The default
  22932. is 6 hours. This keeps @command{gnt-job list} manageable.
  22933. @item @code{verify-disks?} (default: @code{#t})
  22934. If this is @code{#f}, the watcher will not try to repair broken DRBD links
  22935. automatically. Administrators will need to use @command{gnt-cluster verify-disks}
  22936. manually instead.
  22937. @item @code{debug?} (default: @code{#f})
  22938. When @code{#t}, the script performs additional logging for debugging purposes.
  22939. @end table
  22940. @end deftp
  22941. @defvr {Scheme Variable} ganeti-cleaner-service-type
  22942. @command{ganeti-cleaner} is a script designed to run periodically and remove
  22943. old files from the cluster. This service type controls two @dfn{cron jobs}:
  22944. one intended for the master node that permanently purges old cluster jobs,
  22945. and one intended for every node that removes expired X509 certificates, keys,
  22946. and outdated @command{ganeti-watcher} information. Like all Ganeti services,
  22947. it is safe to include even on non-master nodes as it will disable itself as
  22948. necessary.
  22949. It takes a @code{ganeti-cleaner-configuration} object.
  22950. @end defvr
  22951. @deftp {Data Type} ganeti-cleaner-configuration
  22952. @table @asis
  22953. @item @code{ganeti} (default: @code{ganeti})
  22954. The @code{ganeti} package to use for the @command{gnt-cleaner} command.
  22955. @item @code{master-schedule} (default: @code{"45 1 * * *"})
  22956. How often to run the master cleaning job. The default is once per day, at
  22957. 01:45:00.
  22958. @item @code{node-schedule} (default: @code{"45 2 * * *"})
  22959. How often to run the node cleaning job. The default is once per day, at
  22960. 02:45:00.
  22961. @end table
  22962. @end deftp
  22963. @node Version Control Services
  22964. @subsection Version Control Services
  22965. The @code{(gnu services version-control)} module provides a service to
  22966. allow remote access to local Git repositories. There are three options:
  22967. the @code{git-daemon-service}, which provides access to repositories via
  22968. the @code{git://} unsecured TCP-based protocol, extending the
  22969. @code{nginx} web server to proxy some requests to
  22970. @code{git-http-backend}, or providing a web interface with
  22971. @code{cgit-service-type}.
  22972. @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
  22973. Return a service that runs @command{git daemon}, a simple TCP server to
  22974. expose repositories over the Git protocol for anonymous access.
  22975. The optional @var{config} argument should be a
  22976. @code{<git-daemon-configuration>} object, by default it allows read-only
  22977. access to exported@footnote{By creating the magic file
  22978. @file{git-daemon-export-ok} in the repository directory.} repositories under
  22979. @file{/srv/git}.
  22980. @end deffn
  22981. @deftp {Data Type} git-daemon-configuration
  22982. Data type representing the configuration for @code{git-daemon-service}.
  22983. @table @asis
  22984. @item @code{package} (default: @code{git})
  22985. Package object of the Git distributed version control system.
  22986. @item @code{export-all?} (default: @code{#f})
  22987. Whether to allow access for all Git repositories, even if they do not
  22988. have the @file{git-daemon-export-ok} file.
  22989. @item @code{base-path} (default: @file{/srv/git})
  22990. Whether to remap all the path requests as relative to the given path.
  22991. If you run @command{git daemon} with @code{(base-path "/srv/git")} on
  22992. @samp{example.com}, then if you later try to pull
  22993. @indicateurl{git://example.com/hello.git}, git daemon will interpret the
  22994. path as @file{/srv/git/hello.git}.
  22995. @item @code{user-path} (default: @code{#f})
  22996. Whether to allow @code{~user} notation to be used in requests. When
  22997. specified with empty string, requests to
  22998. @indicateurl{git://host/~alice/foo} is taken as a request to access
  22999. @code{foo} repository in the home directory of user @code{alice}. If
  23000. @code{(user-path "@var{path}")} is specified, the same request is taken
  23001. as a request to access @file{@var{path}/foo} repository in the home
  23002. directory of user @code{alice}.
  23003. @item @code{listen} (default: @code{'()})
  23004. Whether to listen on specific IP addresses or hostnames, defaults to
  23005. all.
  23006. @item @code{port} (default: @code{#f})
  23007. Whether to listen on an alternative port, which defaults to 9418.
  23008. @item @code{whitelist} (default: @code{'()})
  23009. If not empty, only allow access to this list of directories.
  23010. @item @code{extra-options} (default: @code{'()})
  23011. Extra options will be passed to @command{git daemon}, please run
  23012. @command{man git-daemon} for more information.
  23013. @end table
  23014. @end deftp
  23015. The @code{git://} protocol lacks authentication. When you pull from a
  23016. repository fetched via @code{git://}, you don't know whether the data you
  23017. receive was modified or is even coming from the specified host, and your
  23018. connection is subject to eavesdropping. It's better to use an authenticated
  23019. and encrypted transport, such as @code{https}. Although Git allows you
  23020. to serve repositories using unsophisticated file-based web servers,
  23021. there is a faster protocol implemented by the @code{git-http-backend}
  23022. program. This program is the back-end of a proper Git web service. It
  23023. is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
  23024. on running the necessary @code{fcgiwrap} daemon.
  23025. Guix has a separate configuration data type for serving Git repositories
  23026. over HTTP.
  23027. @deftp {Data Type} git-http-configuration
  23028. Data type representing the configuration for a future
  23029. @code{git-http-service-type}; can currently be used to configure Nginx
  23030. through @code{git-http-nginx-location-configuration}.
  23031. @table @asis
  23032. @item @code{package} (default: @var{git})
  23033. Package object of the Git distributed version control system.
  23034. @item @code{git-root} (default: @file{/srv/git})
  23035. Directory containing the Git repositories to expose to the world.
  23036. @item @code{export-all?} (default: @code{#f})
  23037. Whether to expose access for all Git repositories in @var{git-root},
  23038. even if they do not have the @file{git-daemon-export-ok} file.
  23039. @item @code{uri-path} (default: @samp{/git/})
  23040. Path prefix for Git access. With the default @samp{/git/} prefix, this
  23041. will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
  23042. @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
  23043. with this prefix are not passed on to this Git instance.
  23044. @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
  23045. The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
  23046. Services}.
  23047. @end table
  23048. @end deftp
  23049. There is no @code{git-http-service-type}, currently; instead you can
  23050. create an @code{nginx-location-configuration} from a
  23051. @code{git-http-configuration} and then add that location to a web
  23052. server.
  23053. @deffn {Scheme Procedure} git-http-nginx-location-configuration @
  23054. [config=(git-http-configuration)]
  23055. Compute an @code{nginx-location-configuration} that corresponds to the
  23056. given Git http configuration. An example nginx service definition to
  23057. serve the default @file{/srv/git} over HTTPS might be:
  23058. @lisp
  23059. (service nginx-service-type
  23060. (nginx-configuration
  23061. (server-blocks
  23062. (list
  23063. (nginx-server-configuration
  23064. (listen '("443 ssl"))
  23065. (server-name "git.my-host.org")
  23066. (ssl-certificate
  23067. "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
  23068. (ssl-certificate-key
  23069. "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
  23070. (locations
  23071. (list
  23072. (git-http-nginx-location-configuration
  23073. (git-http-configuration (uri-path "/"))))))))))
  23074. @end lisp
  23075. This example assumes that you are using Let's Encrypt to get your TLS
  23076. certificate. @xref{Certificate Services}. The default @code{certbot}
  23077. service will redirect all HTTP traffic on @code{git.my-host.org} to
  23078. HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
  23079. system services. @xref{Web Services}.
  23080. @end deffn
  23081. @subsubheading Cgit Service
  23082. @cindex Cgit service
  23083. @cindex Git, web interface
  23084. @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
  23085. repositories written in C.
  23086. The following example will configure the service with default values.
  23087. By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
  23088. @lisp
  23089. (service cgit-service-type)
  23090. @end lisp
  23091. The @code{file-object} type designates either a file-like object
  23092. (@pxref{G-Expressions, file-like objects}) or a string.
  23093. @c %start of fragment
  23094. Available @code{cgit-configuration} fields are:
  23095. @deftypevr {@code{cgit-configuration} parameter} package package
  23096. The CGIT package.
  23097. @end deftypevr
  23098. @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
  23099. NGINX configuration.
  23100. @end deftypevr
  23101. @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
  23102. Specifies a command which will be invoked to format the content of about
  23103. pages (both top-level and for each repository).
  23104. Defaults to @samp{""}.
  23105. @end deftypevr
  23106. @deftypevr {@code{cgit-configuration} parameter} string agefile
  23107. Specifies a path, relative to each repository path, which can be used to
  23108. specify the date and time of the youngest commit in the repository.
  23109. Defaults to @samp{""}.
  23110. @end deftypevr
  23111. @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
  23112. Specifies a command that will be invoked for authenticating repository
  23113. access.
  23114. Defaults to @samp{""}.
  23115. @end deftypevr
  23116. @deftypevr {@code{cgit-configuration} parameter} string branch-sort
  23117. Flag which, when set to @samp{age}, enables date ordering in the branch
  23118. ref list, and when set @samp{name} enables ordering by branch name.
  23119. Defaults to @samp{"name"}.
  23120. @end deftypevr
  23121. @deftypevr {@code{cgit-configuration} parameter} string cache-root
  23122. Path used to store the cgit cache entries.
  23123. Defaults to @samp{"/var/cache/cgit"}.
  23124. @end deftypevr
  23125. @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
  23126. Number which specifies the time-to-live, in minutes, for the cached
  23127. version of repository pages accessed with a fixed SHA1.
  23128. Defaults to @samp{-1}.
  23129. @end deftypevr
  23130. @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
  23131. Number which specifies the time-to-live, in minutes, for the cached
  23132. version of repository pages accessed without a fixed SHA1.
  23133. Defaults to @samp{5}.
  23134. @end deftypevr
  23135. @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
  23136. Number which specifies the time-to-live, in minutes, for the cached
  23137. version of the repository summary page.
  23138. Defaults to @samp{5}.
  23139. @end deftypevr
  23140. @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
  23141. Number which specifies the time-to-live, in minutes, for the cached
  23142. version of the repository index page.
  23143. Defaults to @samp{5}.
  23144. @end deftypevr
  23145. @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
  23146. Number which specifies the time-to-live, in minutes, for the result of
  23147. scanning a path for Git repositories.
  23148. Defaults to @samp{15}.
  23149. @end deftypevr
  23150. @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
  23151. Number which specifies the time-to-live, in minutes, for the cached
  23152. version of the repository about page.
  23153. Defaults to @samp{15}.
  23154. @end deftypevr
  23155. @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
  23156. Number which specifies the time-to-live, in minutes, for the cached
  23157. version of snapshots.
  23158. Defaults to @samp{5}.
  23159. @end deftypevr
  23160. @deftypevr {@code{cgit-configuration} parameter} integer cache-size
  23161. The maximum number of entries in the cgit cache. When set to @samp{0},
  23162. caching is disabled.
  23163. Defaults to @samp{0}.
  23164. @end deftypevr
  23165. @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
  23166. Sort items in the repo list case sensitively.
  23167. Defaults to @samp{#t}.
  23168. @end deftypevr
  23169. @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
  23170. List of common prefixes which, when combined with a repository URL,
  23171. generates valid clone URLs for the repository.
  23172. Defaults to @samp{()}.
  23173. @end deftypevr
  23174. @deftypevr {@code{cgit-configuration} parameter} list clone-url
  23175. List of @code{clone-url} templates.
  23176. Defaults to @samp{()}.
  23177. @end deftypevr
  23178. @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
  23179. Command which will be invoked to format commit messages.
  23180. Defaults to @samp{""}.
  23181. @end deftypevr
  23182. @deftypevr {@code{cgit-configuration} parameter} string commit-sort
  23183. Flag which, when set to @samp{date}, enables strict date ordering in the
  23184. commit log, and when set to @samp{topo} enables strict topological
  23185. ordering.
  23186. Defaults to @samp{"git log"}.
  23187. @end deftypevr
  23188. @deftypevr {@code{cgit-configuration} parameter} file-object css
  23189. URL which specifies the css document to include in all cgit pages.
  23190. Defaults to @samp{"/share/cgit/cgit.css"}.
  23191. @end deftypevr
  23192. @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
  23193. Specifies a command which will be invoked to format names and email
  23194. address of committers, authors, and taggers, as represented in various
  23195. places throughout the cgit interface.
  23196. Defaults to @samp{""}.
  23197. @end deftypevr
  23198. @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
  23199. Flag which, when set to @samp{#t}, will make cgit generate a HTML
  23200. fragment suitable for embedding in other HTML pages.
  23201. Defaults to @samp{#f}.
  23202. @end deftypevr
  23203. @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
  23204. Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
  23205. commit history graph to the left of the commit messages in the
  23206. repository log page.
  23207. Defaults to @samp{#f}.
  23208. @end deftypevr
  23209. @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
  23210. Flag which, when set to @samp{#t}, allows all filter settings to be
  23211. overridden in repository-specific cgitrc files.
  23212. Defaults to @samp{#f}.
  23213. @end deftypevr
  23214. @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
  23215. Flag which, when set to @samp{#t}, allows users to follow a file in the
  23216. log view.
  23217. Defaults to @samp{#f}.
  23218. @end deftypevr
  23219. @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
  23220. If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
  23221. clones.
  23222. Defaults to @samp{#t}.
  23223. @end deftypevr
  23224. @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
  23225. Flag which, when set to @samp{#t}, will make cgit generate extra links
  23226. "summary", "commit", "tree" for each repo in the repository index.
  23227. Defaults to @samp{#f}.
  23228. @end deftypevr
  23229. @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
  23230. Flag which, when set to @samp{#t}, will make cgit display the owner of
  23231. each repo in the repository index.
  23232. Defaults to @samp{#t}.
  23233. @end deftypevr
  23234. @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
  23235. Flag which, when set to @samp{#t}, will make cgit print the number of
  23236. modified files for each commit on the repository log page.
  23237. Defaults to @samp{#f}.
  23238. @end deftypevr
  23239. @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
  23240. Flag which, when set to @samp{#t}, will make cgit print the number of
  23241. added and removed lines for each commit on the repository log page.
  23242. Defaults to @samp{#f}.
  23243. @end deftypevr
  23244. @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
  23245. Flag which, when set to @code{#t}, will make cgit display remote
  23246. branches in the summary and refs views.
  23247. Defaults to @samp{#f}.
  23248. @end deftypevr
  23249. @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
  23250. Flag which, when set to @code{1}, will make cgit use the subject of the
  23251. parent commit as link text when generating links to parent commits in
  23252. commit view.
  23253. Defaults to @samp{#f}.
  23254. @end deftypevr
  23255. @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
  23256. Flag which, when set to @samp{#t}, will make cgit use the subject of the
  23257. parent commit as link text when generating links to parent commits in
  23258. commit view.
  23259. Defaults to @samp{#f}.
  23260. @end deftypevr
  23261. @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
  23262. Flag which, when set to @samp{#t}, will make cgit generate linenumber
  23263. links for plaintext blobs printed in the tree view.
  23264. Defaults to @samp{#t}.
  23265. @end deftypevr
  23266. @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
  23267. Flag which, when set to @samp{#f}, will allow cgit to use Git config to
  23268. set any repo specific settings.
  23269. Defaults to @samp{#f}.
  23270. @end deftypevr
  23271. @deftypevr {@code{cgit-configuration} parameter} file-object favicon
  23272. URL used as link to a shortcut icon for cgit.
  23273. Defaults to @samp{"/favicon.ico"}.
  23274. @end deftypevr
  23275. @deftypevr {@code{cgit-configuration} parameter} string footer
  23276. The content of the file specified with this option will be included
  23277. verbatim at the bottom of all pages (i.e.@: it replaces the standard
  23278. "generated by..."@: message).
  23279. Defaults to @samp{""}.
  23280. @end deftypevr
  23281. @deftypevr {@code{cgit-configuration} parameter} string head-include
  23282. The content of the file specified with this option will be included
  23283. verbatim in the HTML HEAD section on all pages.
  23284. Defaults to @samp{""}.
  23285. @end deftypevr
  23286. @deftypevr {@code{cgit-configuration} parameter} string header
  23287. The content of the file specified with this option will be included
  23288. verbatim at the top of all pages.
  23289. Defaults to @samp{""}.
  23290. @end deftypevr
  23291. @deftypevr {@code{cgit-configuration} parameter} file-object include
  23292. Name of a configfile to include before the rest of the current config-
  23293. file is parsed.
  23294. Defaults to @samp{""}.
  23295. @end deftypevr
  23296. @deftypevr {@code{cgit-configuration} parameter} string index-header
  23297. The content of the file specified with this option will be included
  23298. verbatim above the repository index.
  23299. Defaults to @samp{""}.
  23300. @end deftypevr
  23301. @deftypevr {@code{cgit-configuration} parameter} string index-info
  23302. The content of the file specified with this option will be included
  23303. verbatim below the heading on the repository index page.
  23304. Defaults to @samp{""}.
  23305. @end deftypevr
  23306. @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
  23307. Flag which, if set to @samp{#t}, makes cgit print commit and tag times
  23308. in the servers timezone.
  23309. Defaults to @samp{#f}.
  23310. @end deftypevr
  23311. @deftypevr {@code{cgit-configuration} parameter} file-object logo
  23312. URL which specifies the source of an image which will be used as a logo
  23313. on all cgit pages.
  23314. Defaults to @samp{"/share/cgit/cgit.png"}.
  23315. @end deftypevr
  23316. @deftypevr {@code{cgit-configuration} parameter} string logo-link
  23317. URL loaded when clicking on the cgit logo image.
  23318. Defaults to @samp{""}.
  23319. @end deftypevr
  23320. @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
  23321. Command which will be invoked to format the Owner column of the main
  23322. page.
  23323. Defaults to @samp{""}.
  23324. @end deftypevr
  23325. @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
  23326. Number of items to display in atom feeds view.
  23327. Defaults to @samp{10}.
  23328. @end deftypevr
  23329. @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
  23330. Number of entries to list per page in "log" view.
  23331. Defaults to @samp{50}.
  23332. @end deftypevr
  23333. @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
  23334. Number of commit message characters to display in "log" view.
  23335. Defaults to @samp{80}.
  23336. @end deftypevr
  23337. @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
  23338. Specifies the number of entries to list per page on the repository index
  23339. page.
  23340. Defaults to @samp{50}.
  23341. @end deftypevr
  23342. @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
  23343. Specifies the maximum number of repo description characters to display
  23344. on the repository index page.
  23345. Defaults to @samp{80}.
  23346. @end deftypevr
  23347. @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
  23348. Specifies the maximum size of a blob to display HTML for in KBytes.
  23349. Defaults to @samp{0}.
  23350. @end deftypevr
  23351. @deftypevr {@code{cgit-configuration} parameter} string max-stats
  23352. Maximum statistics period. Valid values are @samp{week},@samp{month},
  23353. @samp{quarter} and @samp{year}.
  23354. Defaults to @samp{""}.
  23355. @end deftypevr
  23356. @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
  23357. Mimetype for the specified filename extension.
  23358. Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
  23359. "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
  23360. "image/png") (svg "image/svg+xml"))}.
  23361. @end deftypevr
  23362. @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
  23363. Specifies the file to use for automatic mimetype lookup.
  23364. Defaults to @samp{""}.
  23365. @end deftypevr
  23366. @deftypevr {@code{cgit-configuration} parameter} string module-link
  23367. Text which will be used as the formatstring for a hyperlink when a
  23368. submodule is printed in a directory listing.
  23369. Defaults to @samp{""}.
  23370. @end deftypevr
  23371. @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
  23372. If set to the value @samp{#t} caching will be disabled.
  23373. Defaults to @samp{#f}.
  23374. @end deftypevr
  23375. @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
  23376. If set to @samp{#t} showing full author email addresses will be
  23377. disabled.
  23378. Defaults to @samp{#f}.
  23379. @end deftypevr
  23380. @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
  23381. Flag which, when set to @samp{#t}, will make cgit omit the standard
  23382. header on all pages.
  23383. Defaults to @samp{#f}.
  23384. @end deftypevr
  23385. @deftypevr {@code{cgit-configuration} parameter} project-list project-list
  23386. A list of subdirectories inside of @code{repository-directory}, relative
  23387. to it, that should loaded as Git repositories. An empty list means that
  23388. all subdirectories will be loaded.
  23389. Defaults to @samp{()}.
  23390. @end deftypevr
  23391. @deftypevr {@code{cgit-configuration} parameter} file-object readme
  23392. Text which will be used as default value for @code{cgit-repo-readme}.
  23393. Defaults to @samp{""}.
  23394. @end deftypevr
  23395. @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
  23396. If set to @code{#t} and @code{repository-directory} is enabled, if any
  23397. repositories are found with a suffix of @code{.git}, this suffix will be
  23398. removed for the URL and name.
  23399. Defaults to @samp{#f}.
  23400. @end deftypevr
  23401. @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
  23402. Maximum number of files to consider when detecting renames.
  23403. Defaults to @samp{-1}.
  23404. @end deftypevr
  23405. @deftypevr {@code{cgit-configuration} parameter} string repository-sort
  23406. The way in which repositories in each section are sorted.
  23407. Defaults to @samp{""}.
  23408. @end deftypevr
  23409. @deftypevr {@code{cgit-configuration} parameter} robots-list robots
  23410. Text used as content for the @code{robots} meta-tag.
  23411. Defaults to @samp{("noindex" "nofollow")}.
  23412. @end deftypevr
  23413. @deftypevr {@code{cgit-configuration} parameter} string root-desc
  23414. Text printed below the heading on the repository index page.
  23415. Defaults to @samp{"a fast webinterface for the git dscm"}.
  23416. @end deftypevr
  23417. @deftypevr {@code{cgit-configuration} parameter} string root-readme
  23418. The content of the file specified with this option will be included
  23419. verbatim below the ``about'' link on the repository index page.
  23420. Defaults to @samp{""}.
  23421. @end deftypevr
  23422. @deftypevr {@code{cgit-configuration} parameter} string root-title
  23423. Text printed as heading on the repository index page.
  23424. Defaults to @samp{""}.
  23425. @end deftypevr
  23426. @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
  23427. If set to @samp{#t} and repository-directory is enabled,
  23428. repository-directory will recurse into directories whose name starts
  23429. with a period. Otherwise, repository-directory will stay away from such
  23430. directories, considered as ``hidden''. Note that this does not apply to
  23431. the @file{.git} directory in non-bare repos.
  23432. Defaults to @samp{#f}.
  23433. @end deftypevr
  23434. @deftypevr {@code{cgit-configuration} parameter} list snapshots
  23435. Text which specifies the default set of snapshot formats that cgit
  23436. generates links for.
  23437. Defaults to @samp{()}.
  23438. @end deftypevr
  23439. @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
  23440. Name of the directory to scan for repositories (represents
  23441. @code{scan-path}).
  23442. Defaults to @samp{"/srv/git"}.
  23443. @end deftypevr
  23444. @deftypevr {@code{cgit-configuration} parameter} string section
  23445. The name of the current repository section - all repositories defined
  23446. after this option will inherit the current section name.
  23447. Defaults to @samp{""}.
  23448. @end deftypevr
  23449. @deftypevr {@code{cgit-configuration} parameter} string section-sort
  23450. Flag which, when set to @samp{1}, will sort the sections on the
  23451. repository listing by name.
  23452. Defaults to @samp{""}.
  23453. @end deftypevr
  23454. @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
  23455. A number which, if defined prior to repository-directory, specifies how
  23456. many path elements from each repo path to use as a default section name.
  23457. Defaults to @samp{0}.
  23458. @end deftypevr
  23459. @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
  23460. If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
  23461. default.
  23462. Defaults to @samp{#f}.
  23463. @end deftypevr
  23464. @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
  23465. Specifies a command which will be invoked to format plaintext blobs in
  23466. the tree view.
  23467. Defaults to @samp{""}.
  23468. @end deftypevr
  23469. @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
  23470. Specifies the number of branches to display in the repository ``summary''
  23471. view.
  23472. Defaults to @samp{10}.
  23473. @end deftypevr
  23474. @deftypevr {@code{cgit-configuration} parameter} integer summary-log
  23475. Specifies the number of log entries to display in the repository
  23476. ``summary'' view.
  23477. Defaults to @samp{10}.
  23478. @end deftypevr
  23479. @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
  23480. Specifies the number of tags to display in the repository ``summary''
  23481. view.
  23482. Defaults to @samp{10}.
  23483. @end deftypevr
  23484. @deftypevr {@code{cgit-configuration} parameter} string strict-export
  23485. Filename which, if specified, needs to be present within the repository
  23486. for cgit to allow access to that repository.
  23487. Defaults to @samp{""}.
  23488. @end deftypevr
  23489. @deftypevr {@code{cgit-configuration} parameter} string virtual-root
  23490. URL which, if specified, will be used as root for all cgit links.
  23491. Defaults to @samp{"/"}.
  23492. @end deftypevr
  23493. @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
  23494. A list of @dfn{cgit-repo} records to use with config.
  23495. Defaults to @samp{()}.
  23496. Available @code{repository-cgit-configuration} fields are:
  23497. @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
  23498. A mask of snapshot formats for this repo that cgit generates links for,
  23499. restricted by the global @code{snapshots} setting.
  23500. Defaults to @samp{()}.
  23501. @end deftypevr
  23502. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
  23503. Override the default @code{source-filter}.
  23504. Defaults to @samp{""}.
  23505. @end deftypevr
  23506. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
  23507. The relative URL used to access the repository.
  23508. Defaults to @samp{""}.
  23509. @end deftypevr
  23510. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
  23511. Override the default @code{about-filter}.
  23512. Defaults to @samp{""}.
  23513. @end deftypevr
  23514. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
  23515. Flag which, when set to @samp{age}, enables date ordering in the branch
  23516. ref list, and when set to @samp{name} enables ordering by branch name.
  23517. Defaults to @samp{""}.
  23518. @end deftypevr
  23519. @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
  23520. A list of URLs which can be used to clone repo.
  23521. Defaults to @samp{()}.
  23522. @end deftypevr
  23523. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
  23524. Override the default @code{commit-filter}.
  23525. Defaults to @samp{""}.
  23526. @end deftypevr
  23527. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
  23528. Flag which, when set to @samp{date}, enables strict date ordering in the
  23529. commit log, and when set to @samp{topo} enables strict topological
  23530. ordering.
  23531. Defaults to @samp{""}.
  23532. @end deftypevr
  23533. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
  23534. The name of the default branch for this repository. If no such branch
  23535. exists in the repository, the first branch name (when sorted) is used as
  23536. default instead. By default branch pointed to by HEAD, or ``master'' if
  23537. there is no suitable HEAD.
  23538. Defaults to @samp{""}.
  23539. @end deftypevr
  23540. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
  23541. The value to show as repository description.
  23542. Defaults to @samp{""}.
  23543. @end deftypevr
  23544. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
  23545. The value to show as repository homepage.
  23546. Defaults to @samp{""}.
  23547. @end deftypevr
  23548. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
  23549. Override the default @code{email-filter}.
  23550. Defaults to @samp{""}.
  23551. @end deftypevr
  23552. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
  23553. A flag which can be used to disable the global setting
  23554. @code{enable-commit-graph?}.
  23555. Defaults to @samp{disabled}.
  23556. @end deftypevr
  23557. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
  23558. A flag which can be used to disable the global setting
  23559. @code{enable-log-filecount?}.
  23560. Defaults to @samp{disabled}.
  23561. @end deftypevr
  23562. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
  23563. A flag which can be used to disable the global setting
  23564. @code{enable-log-linecount?}.
  23565. Defaults to @samp{disabled}.
  23566. @end deftypevr
  23567. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
  23568. Flag which, when set to @code{#t}, will make cgit display remote
  23569. branches in the summary and refs views.
  23570. Defaults to @samp{disabled}.
  23571. @end deftypevr
  23572. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
  23573. A flag which can be used to override the global setting
  23574. @code{enable-subject-links?}.
  23575. Defaults to @samp{disabled}.
  23576. @end deftypevr
  23577. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
  23578. A flag which can be used to override the global setting
  23579. @code{enable-html-serving?}.
  23580. Defaults to @samp{disabled}.
  23581. @end deftypevr
  23582. @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
  23583. Flag which, when set to @code{#t}, hides the repository from the
  23584. repository index.
  23585. Defaults to @samp{#f}.
  23586. @end deftypevr
  23587. @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
  23588. Flag which, when set to @samp{#t}, ignores the repository.
  23589. Defaults to @samp{#f}.
  23590. @end deftypevr
  23591. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
  23592. URL which specifies the source of an image which will be used as a logo
  23593. on this repo’s pages.
  23594. Defaults to @samp{""}.
  23595. @end deftypevr
  23596. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
  23597. URL loaded when clicking on the cgit logo image.
  23598. Defaults to @samp{""}.
  23599. @end deftypevr
  23600. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
  23601. Override the default @code{owner-filter}.
  23602. Defaults to @samp{""}.
  23603. @end deftypevr
  23604. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
  23605. Text which will be used as the formatstring for a hyperlink when a
  23606. submodule is printed in a directory listing. The arguments for the
  23607. formatstring are the path and SHA1 of the submodule commit.
  23608. Defaults to @samp{""}.
  23609. @end deftypevr
  23610. @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
  23611. Text which will be used as the formatstring for a hyperlink when a
  23612. submodule with the specified subdirectory path is printed in a directory
  23613. listing.
  23614. Defaults to @samp{()}.
  23615. @end deftypevr
  23616. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
  23617. Override the default maximum statistics period.
  23618. Defaults to @samp{""}.
  23619. @end deftypevr
  23620. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
  23621. The value to show as repository name.
  23622. Defaults to @samp{""}.
  23623. @end deftypevr
  23624. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
  23625. A value used to identify the owner of the repository.
  23626. Defaults to @samp{""}.
  23627. @end deftypevr
  23628. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
  23629. An absolute path to the repository directory.
  23630. Defaults to @samp{""}.
  23631. @end deftypevr
  23632. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
  23633. A path (relative to repo) which specifies a file to include verbatim as
  23634. the ``About'' page for this repo.
  23635. Defaults to @samp{""}.
  23636. @end deftypevr
  23637. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
  23638. The name of the current repository section - all repositories defined
  23639. after this option will inherit the current section name.
  23640. Defaults to @samp{""}.
  23641. @end deftypevr
  23642. @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
  23643. Extra options will be appended to cgitrc file.
  23644. Defaults to @samp{()}.
  23645. @end deftypevr
  23646. @end deftypevr
  23647. @deftypevr {@code{cgit-configuration} parameter} list extra-options
  23648. Extra options will be appended to cgitrc file.
  23649. Defaults to @samp{()}.
  23650. @end deftypevr
  23651. @c %end of fragment
  23652. However, it could be that you just want to get a @code{cgitrc} up and
  23653. running. In that case, you can pass an @code{opaque-cgit-configuration}
  23654. as a record to @code{cgit-service-type}. As its name indicates, an
  23655. opaque configuration does not have easy reflective capabilities.
  23656. Available @code{opaque-cgit-configuration} fields are:
  23657. @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
  23658. The cgit package.
  23659. @end deftypevr
  23660. @deftypevr {@code{opaque-cgit-configuration} parameter} string string
  23661. The contents of the @code{cgitrc}, as a string.
  23662. @end deftypevr
  23663. For example, if your @code{cgitrc} is just the empty string, you
  23664. could instantiate a cgit service like this:
  23665. @lisp
  23666. (service cgit-service-type
  23667. (opaque-cgit-configuration
  23668. (cgitrc "")))
  23669. @end lisp
  23670. @subsubheading Gitolite Service
  23671. @cindex Gitolite service
  23672. @cindex Git, hosting
  23673. @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
  23674. repositories on a central server.
  23675. Gitolite can handle multiple repositories and users, and supports flexible
  23676. configuration of the permissions for the users on the repositories.
  23677. The following example will configure Gitolite using the default @code{git}
  23678. user, and the provided SSH public key.
  23679. @lisp
  23680. (service gitolite-service-type
  23681. (gitolite-configuration
  23682. (admin-pubkey (plain-file
  23683. "yourname.pub"
  23684. "ssh-rsa AAAA... guix@@example.com"))))
  23685. @end lisp
  23686. Gitolite is configured through a special admin repository which you can clone,
  23687. for example, if you setup Gitolite on @code{example.com}, you would run the
  23688. following command to clone the admin repository.
  23689. @example
  23690. git clone git@@example.com:gitolite-admin
  23691. @end example
  23692. When the Gitolite service is activated, the provided @code{admin-pubkey} will
  23693. be inserted in to the @file{keydir} directory in the gitolite-admin
  23694. repository. If this results in a change in the repository, it will be
  23695. committed using the message ``gitolite setup by GNU Guix''.
  23696. @deftp {Data Type} gitolite-configuration
  23697. Data type representing the configuration for @code{gitolite-service-type}.
  23698. @table @asis
  23699. @item @code{package} (default: @var{gitolite})
  23700. Gitolite package to use.
  23701. @item @code{user} (default: @var{git})
  23702. User to use for Gitolite. This will be user that you use when accessing
  23703. Gitolite over SSH.
  23704. @item @code{group} (default: @var{git})
  23705. Group to use for Gitolite.
  23706. @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
  23707. Directory in which to store the Gitolite configuration and repositories.
  23708. @item @code{rc-file} (default: @var{(gitolite-rc-file)})
  23709. A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
  23710. representing the configuration for Gitolite.
  23711. @item @code{admin-pubkey} (default: @var{#f})
  23712. A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
  23713. setup Gitolite. This will be inserted in to the @file{keydir} directory
  23714. within the gitolite-admin repository.
  23715. To specify the SSH key as a string, use the @code{plain-file} function.
  23716. @lisp
  23717. (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
  23718. @end lisp
  23719. @end table
  23720. @end deftp
  23721. @deftp {Data Type} gitolite-rc-file
  23722. Data type representing the Gitolite RC file.
  23723. @table @asis
  23724. @item @code{umask} (default: @code{#o0077})
  23725. This controls the permissions Gitolite sets on the repositories and their
  23726. contents.
  23727. A value like @code{#o0027} will give read access to the group used by Gitolite
  23728. (by default: @code{git}). This is necessary when using Gitolite with software
  23729. like cgit or gitweb.
  23730. @item @code{git-config-keys} (default: @code{""})
  23731. Gitolite allows you to set git config values using the @samp{config}
  23732. keyword. This setting allows control over the config keys to accept.
  23733. @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
  23734. Set the role names allowed to be used by users running the perms command.
  23735. @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
  23736. This setting controls the commands and features to enable within Gitolite.
  23737. @end table
  23738. @end deftp
  23739. @node Game Services
  23740. @subsection Game Services
  23741. @subsubheading The Battle for Wesnoth Service
  23742. @cindex wesnothd
  23743. @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
  23744. based tactical strategy game, with several single player campaigns, and
  23745. multiplayer games (both networked and local).
  23746. @defvar {Scheme Variable} wesnothd-service-type
  23747. Service type for the wesnothd service. Its value must be a
  23748. @code{wesnothd-configuration} object. To run wesnothd in the default
  23749. configuration, instantiate it as:
  23750. @lisp
  23751. (service wesnothd-service-type)
  23752. @end lisp
  23753. @end defvar
  23754. @deftp {Data Type} wesnothd-configuration
  23755. Data type representing the configuration of @command{wesnothd}.
  23756. @table @asis
  23757. @item @code{package} (default: @code{wesnoth-server})
  23758. The wesnoth server package to use.
  23759. @item @code{port} (default: @code{15000})
  23760. The port to bind the server to.
  23761. @end table
  23762. @end deftp
  23763. @node PAM Mount Service
  23764. @subsection PAM Mount Service
  23765. @cindex pam-mount
  23766. The @code{(gnu services pam-mount)} module provides a service allowing
  23767. users to mount volumes when they log in. It should be able to mount any
  23768. volume format supported by the system.
  23769. @defvar {Scheme Variable} pam-mount-service-type
  23770. Service type for PAM Mount support.
  23771. @end defvar
  23772. @deftp {Data Type} pam-mount-configuration
  23773. Data type representing the configuration of PAM Mount.
  23774. It takes the following parameters:
  23775. @table @asis
  23776. @item @code{rules}
  23777. The configuration rules that will be used to generate
  23778. @file{/etc/security/pam_mount.conf.xml}.
  23779. The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
  23780. Guile Reference Manual}), and the default ones don't mount anything for
  23781. anyone at login:
  23782. @lisp
  23783. `((debug (@@ (enable "0")))
  23784. (mntoptions (@@ (allow ,(string-join
  23785. '("nosuid" "nodev" "loop"
  23786. "encryption" "fsck" "nonempty"
  23787. "allow_root" "allow_other")
  23788. ","))))
  23789. (mntoptions (@@ (require "nosuid,nodev")))
  23790. (logout (@@ (wait "0")
  23791. (hup "0")
  23792. (term "no")
  23793. (kill "no")))
  23794. (mkmountpoint (@@ (enable "1")
  23795. (remove "true"))))
  23796. @end lisp
  23797. Some @code{volume} elements must be added to automatically mount volumes
  23798. at login. Here's an example allowing the user @code{alice} to mount her
  23799. encrypted @env{HOME} directory and allowing the user @code{bob} to mount
  23800. the partition where he stores his data:
  23801. @lisp
  23802. (define pam-mount-rules
  23803. `((debug (@@ (enable "0")))
  23804. (volume (@@ (user "alice")
  23805. (fstype "crypt")
  23806. (path "/dev/sda2")
  23807. (mountpoint "/home/alice")))
  23808. (volume (@@ (user "bob")
  23809. (fstype "auto")
  23810. (path "/dev/sdb3")
  23811. (mountpoint "/home/bob/data")
  23812. (options "defaults,autodefrag,compress")))
  23813. (mntoptions (@@ (allow ,(string-join
  23814. '("nosuid" "nodev" "loop"
  23815. "encryption" "fsck" "nonempty"
  23816. "allow_root" "allow_other")
  23817. ","))))
  23818. (mntoptions (@@ (require "nosuid,nodev")))
  23819. (logout (@@ (wait "0")
  23820. (hup "0")
  23821. (term "no")
  23822. (kill "no")))
  23823. (mkmountpoint (@@ (enable "1")
  23824. (remove "true")))))
  23825. (service pam-mount-service-type
  23826. (pam-mount-configuration
  23827. (rules pam-mount-rules)))
  23828. @end lisp
  23829. The complete list of possible options can be found in the man page for
  23830. @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
  23831. @end table
  23832. @end deftp
  23833. @node Guix Services
  23834. @subsection Guix Services
  23835. @subsubheading Guix Build Coordinator
  23836. The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
  23837. Coordinator} aids in distributing derivation builds among machines
  23838. running an @dfn{agent}. The build daemon is still used to build the
  23839. derivations, but the Guix Build Coordinator manages allocating builds
  23840. and working with the results.
  23841. @quotation Note
  23842. This service is considered experimental. Configuration options may be
  23843. changed in a backwards-incompatible manner, and not all features have
  23844. been thorougly tested.
  23845. @end quotation
  23846. The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
  23847. more connected @dfn{agent} processes. The coordinator process handles
  23848. clients submitting builds, and allocating builds to agents. The agent
  23849. processes talk to a build daemon to actually perform the builds, then
  23850. send the results back to the coordinator.
  23851. There is a script to run the coordinator component of the Guix Build
  23852. Coordinator, but the Guix service uses a custom Guile script instead, to
  23853. provide better integration with G-expressions used in the configuration.
  23854. @defvar {Scheme Variable} guix-build-coordinator-service-type
  23855. Service type for the Guix Build Coordinator. Its value must be a
  23856. @code{guix-build-coordinator-configuration} object.
  23857. @end defvar
  23858. @deftp {Data Type} guix-build-coordinator-configuration
  23859. Data type representing the configuration of the Guix Build Coordinator.
  23860. @table @asis
  23861. @item @code{package} (default: @code{guix-build-coordinator})
  23862. The Guix Build Coordinator package to use.
  23863. @item @code{user} (default: @code{"guix-build-coordinator"})
  23864. The system user to run the service as.
  23865. @item @code{group} (default: @code{"guix-build-coordinator"})
  23866. The system group to run the service as.
  23867. @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
  23868. The URI to use for the database.
  23869. @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
  23870. The URI describing how to listen to requests from agent processes.
  23871. @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
  23872. The URI describing how to listen to requests from clients. The client
  23873. API allows submitting builds and currently isn't authenticated, so take
  23874. care when configuring this value.
  23875. @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
  23876. A G-expression for the allocation strategy to be used. This is a
  23877. procedure that takes the datastore as an argument and populates the
  23878. allocation plan in the database.
  23879. @item @code{hooks} (default: @var{'()})
  23880. An association list of hooks. These provide a way to execute arbitrary
  23881. code upon certain events, like a build result being processed.
  23882. @item @code{guile} (default: @code{guile-3.0-latest})
  23883. The Guile package with which to run the Guix Build Coordinator.
  23884. @end table
  23885. @end deftp
  23886. @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
  23887. Service type for a Guix Build Coordinator agent. Its value must be a
  23888. @code{guix-build-coordinator-agent-configuration} object.
  23889. @end defvar
  23890. @deftp {Data Type} guix-build-coordinator-agent-configuration
  23891. Data type representing the configuration a Guix Build Coordinator agent.
  23892. @table @asis
  23893. @item @code{package} (default: @code{guix-build-coordinator})
  23894. The Guix Build Coordinator package to use.
  23895. @item @code{user} (default: @code{"guix-build-coordinator-agent"})
  23896. The system user to run the service as.
  23897. @item @code{coordinator} (default: @code{"http://localhost:8745"})
  23898. The URI to use when connecting to the coordinator.
  23899. @item @code{uuid}
  23900. The UUID of the agent. This should be generated by the coordinator
  23901. process, stored in the coordinator database, and used by the intended
  23902. agent.
  23903. @item @code{password} (default: @code{#f})
  23904. The password to use when connecting to the coordinator. A file to read
  23905. the password from can also be specified, and this is more secure.
  23906. @item @code{password-file} (default: @code{#f})
  23907. A file containing the password to use when connecting to the
  23908. coordinator.
  23909. @item @code{systems} (default: @code{#f})
  23910. The systems for which this agent should fetch builds. The agent process
  23911. will use the current system it's running on as the default.
  23912. @item @code{max-parallel-builds} (default: @code{1})
  23913. The number of builds to perform in parallel.
  23914. @item @code{derivation-substitute-urls} (default: @code{#f})
  23915. URLs from which to attempt to fetch substitutes for derivations, if the
  23916. derivations aren't already available.
  23917. @item @code{non-derivation-substitute-urls} (default: @code{#f})
  23918. URLs from which to attempt to fetch substitutes for build inputs, if the
  23919. input store items aren't already available.
  23920. @end table
  23921. @end deftp
  23922. The Guix Build Coordinator package contains a script to query an
  23923. instance of the Guix Data Service for derivations to build, and then
  23924. submit builds for those derivations to the coordinator. The service
  23925. type below assists in running this script. This is an additional tool
  23926. that may be useful when building derivations contained within an
  23927. instance of the Guix Data Service.
  23928. @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
  23929. Service type for the
  23930. guix-build-coordinator-queue-builds-from-guix-data-service script. Its
  23931. value must be a @code{guix-build-coordinator-queue-builds-configuration}
  23932. object.
  23933. @end defvar
  23934. @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
  23935. Data type representing the options to the queue builds from guix data
  23936. service script.
  23937. @table @asis
  23938. @item @code{package} (default: @code{guix-build-coordinator})
  23939. The Guix Build Coordinator package to use.
  23940. @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
  23941. The system user to run the service as.
  23942. @item @code{coordinator} (default: @code{"http://localhost:8745"})
  23943. The URI to use when connecting to the coordinator.
  23944. @item @code{systems} (default: @code{#f})
  23945. The systems for which to fetch derivations to build.
  23946. @item @code{systems-and-targets} (default: @code{#f})
  23947. An association list of system and target pairs for which to fetch
  23948. derivations to build.
  23949. @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
  23950. The Guix Data Service instance from which to query to find out about
  23951. derivations to build.
  23952. @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
  23953. A file to record which commits have been processed, to avoid needlessly
  23954. processing them again if the service is restarted.
  23955. @end table
  23956. @end deftp
  23957. @subsubheading Guix Data Service
  23958. The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
  23959. and provides data about GNU Guix. This includes information about
  23960. packages, derivations and lint warnings.
  23961. The data is stored in a PostgreSQL database, and available through a web
  23962. interface.
  23963. @defvar {Scheme Variable} guix-data-service-type
  23964. Service type for the Guix Data Service. Its value must be a
  23965. @code{guix-data-service-configuration} object. The service optionally
  23966. extends the getmail service, as the guix-commits mailing list is used to
  23967. find out about changes in the Guix git repository.
  23968. @end defvar
  23969. @deftp {Data Type} guix-data-service-configuration
  23970. Data type representing the configuration of the Guix Data Service.
  23971. @table @asis
  23972. @item @code{package} (default: @code{guix-data-service})
  23973. The Guix Data Service package to use.
  23974. @item @code{user} (default: @code{"guix-data-service"})
  23975. The system user to run the service as.
  23976. @item @code{group} (default: @code{"guix-data-service"})
  23977. The system group to run the service as.
  23978. @item @code{port} (default: @code{8765})
  23979. The port to bind the web service to.
  23980. @item @code{host} (default: @code{"127.0.0.1"})
  23981. The host to bind the web service to.
  23982. @item @code{getmail-idle-mailboxes} (default: @code{#f})
  23983. If set, this is the list of mailboxes that the getmail service will be
  23984. configured to listen to.
  23985. @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
  23986. If set, this is the @code{getmail-retriever-configuration} object with
  23987. which to configure getmail to fetch mail from the guix-commits mailing
  23988. list.
  23989. @item @code{extra-options} (default: @var{'()})
  23990. Extra command line options for @code{guix-data-service}.
  23991. @item @code{extra-process-jobs-options} (default: @var{'()})
  23992. Extra command line options for @code{guix-data-service-process-jobs}.
  23993. @end table
  23994. @end deftp
  23995. @node Linux Services
  23996. @subsection Linux Services
  23997. @cindex oom
  23998. @cindex out of memory killer
  23999. @cindex earlyoom
  24000. @cindex early out of memory daemon
  24001. @subsubheading Early OOM Service
  24002. @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
  24003. Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
  24004. space and provides a more responsive and configurable alternative to the
  24005. in-kernel OOM killer. It is useful to prevent the system from becoming
  24006. unresponsive when it runs out of memory.
  24007. @deffn {Scheme Variable} earlyoom-service-type
  24008. The service type for running @command{earlyoom}, the Early OOM daemon.
  24009. Its value must be a @code{earlyoom-configuration} object, described
  24010. below. The service can be instantiated in its default configuration
  24011. with:
  24012. @lisp
  24013. (service earlyoom-service-type)
  24014. @end lisp
  24015. @end deffn
  24016. @deftp {Data Type} earlyoom-configuration
  24017. This is the configuration record for the @code{earlyoom-service-type}.
  24018. @table @asis
  24019. @item @code{earlyoom} (default: @var{earlyoom})
  24020. The Earlyoom package to use.
  24021. @item @code{minimum-available-memory} (default: @code{10})
  24022. The threshold for the minimum @emph{available} memory, in percentages.
  24023. @item @code{minimum-free-swap} (default: @code{10})
  24024. The threshold for the minimum free swap memory, in percentages.
  24025. @item @code{prefer-regexp} (default: @code{#f})
  24026. A regular expression (as a string) to match the names of the processes
  24027. that should be preferably killed.
  24028. @item @code{avoid-regexp} (default: @code{#f})
  24029. A regular expression (as a string) to match the names of the processes
  24030. that should @emph{not} be killed.
  24031. @item @code{memory-report-interval} (default: @code{0})
  24032. The interval in seconds at which a memory report is printed. It is
  24033. disabled by default.
  24034. @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
  24035. A boolean indicating whether the positive adjustments set in
  24036. @file{/proc/*/oom_score_adj} should be ignored.
  24037. @item @code{show-debug-messages?} (default: @code{#f})
  24038. A boolean indicating whether debug messages should be printed. The logs
  24039. are saved at @file{/var/log/earlyoom.log}.
  24040. @item @code{send-notification-command} (default: @code{#f})
  24041. This can be used to provide a custom command used for sending
  24042. notifications.
  24043. @end table
  24044. @end deftp
  24045. @cindex modprobe
  24046. @cindex kernel module loader
  24047. @subsubheading Kernel Module Loader Service
  24048. The kernel module loader service allows one to load loadable kernel
  24049. modules at boot. This is especially useful for modules that don't
  24050. autoload and need to be manually loaded, as it's the case with
  24051. @code{ddcci}.
  24052. @deffn {Scheme Variable} kernel-module-loader-service-type
  24053. The service type for loading loadable kernel modules at boot with
  24054. @command{modprobe}. Its value must be a list of strings representing
  24055. module names. For example loading the drivers provided by
  24056. @code{ddcci-driver-linux}, in debugging mode by passing some module
  24057. parameters, can be done as follow:
  24058. @lisp
  24059. (use-modules (gnu) (gnu services))
  24060. (use-package-modules linux)
  24061. (use-service-modules linux)
  24062. (define ddcci-config
  24063. (plain-file "ddcci.conf"
  24064. "options ddcci dyndbg delay=120"))
  24065. (operating-system
  24066. ...
  24067. (services (cons* (service kernel-module-loader-service-type
  24068. '("ddcci" "ddcci_backlight"))
  24069. (simple-service 'ddcci-config etc-service-type
  24070. (list `("modprobe.d/ddcci.conf"
  24071. ,ddcci-config)))
  24072. %base-services))
  24073. (kernel-loadable-modules (list ddcci-driver-linux)))
  24074. @end lisp
  24075. @end deffn
  24076. @cindex zram
  24077. @cindex compressed swap
  24078. @cindex Compressed RAM-based block devices
  24079. @subsubheading Zram Device Service
  24080. The Zram device service provides a compressed swap device in system
  24081. memory. The Linux Kernel documentation has more information about
  24082. @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
  24083. devices.
  24084. @deffn {Scheme Variable} zram-device-service-type
  24085. This service creates the zram block device, formats it as swap and
  24086. enables it as a swap device. The service's value is a
  24087. @code{zram-device-configuration} record.
  24088. @deftp {Data Type} zram-device-configuration
  24089. This is the data type representing the configuration for the zram-device
  24090. service.
  24091. @table @asis
  24092. @item @code{size} (default @code{"1G"})
  24093. This is the amount of space you wish to provide for the zram device. It
  24094. accepts a string and can be a number of bytes or use a suffix, eg.:
  24095. @code{"512M"} or @code{1024000}.
  24096. @item @code{compression-algorithm} (default @code{'lzo})
  24097. This is the compression algorithm you wish to use. It is difficult to
  24098. list all the possible compression options, but common ones supported by
  24099. Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
  24100. @item @code{memory-limit} (default @code{0})
  24101. This is the maximum amount of memory which the zram device can use.
  24102. Setting it to '0' disables the limit. While it is generally expected
  24103. that compression will be 2:1, it is possible that uncompressable data
  24104. can be written to swap and this is a method to limit how much memory can
  24105. be used. It accepts a string and can be a number of bytes or use a
  24106. suffix, eg.: @code{"2G"}.
  24107. @item @code{priority} (default @code{-1})
  24108. This is the priority of the swap device created from the zram device.
  24109. @code{swapon} accepts values between -1 and 32767, with higher values
  24110. indicating higher priority. Higher priority swap will generally be used
  24111. first.
  24112. @end table
  24113. @end deftp
  24114. @end deffn
  24115. @node Hurd Services
  24116. @subsection Hurd Services
  24117. @defvr {Scheme Variable} hurd-console-service-type
  24118. This service starts the fancy @code{VGA} console client on the Hurd.
  24119. The service's value is a @code{hurd-console-configuration} record.
  24120. @end defvr
  24121. @deftp {Data Type} hurd-console-configuration
  24122. This is the data type representing the configuration for the
  24123. hurd-console-service.
  24124. @table @asis
  24125. @item @code{hurd} (default: @var{hurd})
  24126. The Hurd package to use.
  24127. @end table
  24128. @end deftp
  24129. @defvr {Scheme Variable} hurd-getty-service-type
  24130. This service starts a tty using the Hurd @code{getty} program.
  24131. The service's value is a @code{hurd-getty-configuration} record.
  24132. @end defvr
  24133. @deftp {Data Type} hurd-getty-configuration
  24134. This is the data type representing the configuration for the
  24135. hurd-getty-service.
  24136. @table @asis
  24137. @item @code{hurd} (default: @var{hurd})
  24138. The Hurd package to use.
  24139. @item @code{tty}
  24140. The name of the console this Getty runs on---e.g., @code{"tty1"}.
  24141. @item @code{baud-rate} (default: @code{38400})
  24142. An integer specifying the baud rate of the tty.
  24143. @end table
  24144. @end deftp
  24145. @node Miscellaneous Services
  24146. @subsection Miscellaneous Services
  24147. @cindex fingerprint
  24148. @subsubheading Fingerprint Service
  24149. The @code{(gnu services authentication)} module provides a DBus service to
  24150. read and identify fingerprints via a fingerprint sensor.
  24151. @defvr {Scheme Variable} fprintd-service-type
  24152. The service type for @command{fprintd}, which provides the fingerprint
  24153. reading capability.
  24154. @lisp
  24155. (service fprintd-service-type)
  24156. @end lisp
  24157. @end defvr
  24158. @cindex sysctl
  24159. @subsubheading System Control Service
  24160. The @code{(gnu services sysctl)} provides a service to configure kernel
  24161. parameters at boot.
  24162. @defvr {Scheme Variable} sysctl-service-type
  24163. The service type for @command{sysctl}, which modifies kernel parameters
  24164. under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
  24165. instantiated as:
  24166. @lisp
  24167. (service sysctl-service-type
  24168. (sysctl-configuration
  24169. (settings '(("net.ipv4.ip_forward" . "1")))))
  24170. @end lisp
  24171. @end defvr
  24172. @deftp {Data Type} sysctl-configuration
  24173. The data type representing the configuration of @command{sysctl}.
  24174. @table @asis
  24175. @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
  24176. The @command{sysctl} executable to use.
  24177. @item @code{settings} (default: @code{'()})
  24178. An association list specifies kernel parameters and their values.
  24179. @end table
  24180. @end deftp
  24181. @cindex pcscd
  24182. @subsubheading PC/SC Smart Card Daemon Service
  24183. The @code{(gnu services security-token)} module provides the following service
  24184. to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
  24185. daemon program for pcsc-lite and the MuscleCard framework. It is a resource
  24186. manager that coordinates communications with smart card readers, smart cards
  24187. and cryptographic tokens that are connected to the system.
  24188. @defvr {Scheme Variable} pcscd-service-type
  24189. Service type for the @command{pcscd} service. Its value must be a
  24190. @code{pcscd-configuration} object. To run pcscd in the default
  24191. configuration, instantiate it as:
  24192. @lisp
  24193. (service pcscd-service-type)
  24194. @end lisp
  24195. @end defvr
  24196. @deftp {Data Type} pcscd-configuration
  24197. The data type representing the configuration of @command{pcscd}.
  24198. @table @asis
  24199. @item @code{pcsc-lite} (default: @code{pcsc-lite})
  24200. The pcsc-lite package that provides pcscd.
  24201. @item @code{usb-drivers} (default: @code{(list ccid)})
  24202. List of packages that provide USB drivers to pcscd. Drivers are expected to be
  24203. under @file{pcsc/drivers} in the store directory of the package.
  24204. @end table
  24205. @end deftp
  24206. @cindex lirc
  24207. @subsubheading Lirc Service
  24208. The @code{(gnu services lirc)} module provides the following service.
  24209. @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
  24210. [#:device #f] [#:driver #f] [#:config-file #f] @
  24211. [#:extra-options '()]
  24212. Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
  24213. decodes infrared signals from remote controls.
  24214. Optionally, @var{device}, @var{driver} and @var{config-file}
  24215. (configuration file name) may be specified. See @command{lircd} manual
  24216. for details.
  24217. Finally, @var{extra-options} is a list of additional command-line options
  24218. passed to @command{lircd}.
  24219. @end deffn
  24220. @cindex spice
  24221. @subsubheading Spice Service
  24222. The @code{(gnu services spice)} module provides the following service.
  24223. @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
  24224. Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
  24225. that enables sharing the clipboard with a vm and setting the guest display
  24226. resolution when the graphical console window resizes.
  24227. @end deffn
  24228. @cindex inputattach
  24229. @subsubheading inputattach Service
  24230. @cindex tablet input, for Xorg
  24231. @cindex touchscreen input, for Xorg
  24232. The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
  24233. use input devices such as Wacom tablets, touchscreens, or joysticks with the
  24234. Xorg display server.
  24235. @deffn {Scheme Variable} inputattach-service-type
  24236. Type of a service that runs @command{inputattach} on a device and
  24237. dispatches events from it.
  24238. @end deffn
  24239. @deftp {Data Type} inputattach-configuration
  24240. @table @asis
  24241. @item @code{device-type} (default: @code{"wacom"})
  24242. The type of device to connect to. Run @command{inputattach --help}, from the
  24243. @code{inputattach} package, to see the list of supported device types.
  24244. @item @code{device} (default: @code{"/dev/ttyS0"})
  24245. The device file to connect to the device.
  24246. @item @code{baud-rate} (default: @code{#f})
  24247. Baud rate to use for the serial connection.
  24248. Should be a number or @code{#f}.
  24249. @item @code{log-file} (default: @code{#f})
  24250. If true, this must be the name of a file to log messages to.
  24251. @end table
  24252. @end deftp
  24253. @subsubheading Dictionary Service
  24254. @cindex dictionary
  24255. The @code{(gnu services dict)} module provides the following service:
  24256. @defvr {Scheme Variable} dicod-service-type
  24257. This is the type of the service that runs the @command{dicod} daemon, an
  24258. implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
  24259. @end defvr
  24260. @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
  24261. Return a service that runs the @command{dicod} daemon, an implementation
  24262. of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
  24263. The optional @var{config} argument specifies the configuration for
  24264. @command{dicod}, which should be a @code{<dicod-configuration>} object, by
  24265. default it serves the GNU Collaborative International Dictionary of English.
  24266. You can add @command{open localhost} to your @file{~/.dico} file to make
  24267. @code{localhost} the default server for @command{dico} client
  24268. (@pxref{Initialization File,,, dico, GNU Dico Manual}).
  24269. @end deffn
  24270. @deftp {Data Type} dicod-configuration
  24271. Data type representing the configuration of dicod.
  24272. @table @asis
  24273. @item @code{dico} (default: @var{dico})
  24274. Package object of the GNU Dico dictionary server.
  24275. @item @code{interfaces} (default: @var{'("localhost")})
  24276. This is the list of IP addresses and ports and possibly socket file
  24277. names to listen to (@pxref{Server Settings, @code{listen} directive,,
  24278. dico, GNU Dico Manual}).
  24279. @item @code{handlers} (default: @var{'()})
  24280. List of @code{<dicod-handler>} objects denoting handlers (module instances).
  24281. @item @code{databases} (default: @var{(list %dicod-database:gcide)})
  24282. List of @code{<dicod-database>} objects denoting dictionaries to be served.
  24283. @end table
  24284. @end deftp
  24285. @deftp {Data Type} dicod-handler
  24286. Data type representing a dictionary handler (module instance).
  24287. @table @asis
  24288. @item @code{name}
  24289. Name of the handler (module instance).
  24290. @item @code{module} (default: @var{#f})
  24291. Name of the dicod module of the handler (instance). If it is @code{#f},
  24292. the module has the same name as the handler.
  24293. (@pxref{Modules,,, dico, GNU Dico Manual}).
  24294. @item @code{options}
  24295. List of strings or gexps representing the arguments for the module handler
  24296. @end table
  24297. @end deftp
  24298. @deftp {Data Type} dicod-database
  24299. Data type representing a dictionary database.
  24300. @table @asis
  24301. @item @code{name}
  24302. Name of the database, will be used in DICT commands.
  24303. @item @code{handler}
  24304. Name of the dicod handler (module instance) used by this database
  24305. (@pxref{Handlers,,, dico, GNU Dico Manual}).
  24306. @item @code{complex?} (default: @var{#f})
  24307. Whether the database configuration complex. The complex configuration
  24308. will need a corresponding @code{<dicod-handler>} object, otherwise not.
  24309. @item @code{options}
  24310. List of strings or gexps representing the arguments for the database
  24311. (@pxref{Databases,,, dico, GNU Dico Manual}).
  24312. @end table
  24313. @end deftp
  24314. @defvr {Scheme Variable} %dicod-database:gcide
  24315. A @code{<dicod-database>} object serving the GNU Collaborative International
  24316. Dictionary of English using the @code{gcide} package.
  24317. @end defvr
  24318. The following is an example @code{dicod-service} configuration.
  24319. @lisp
  24320. (dicod-service #:config
  24321. (dicod-configuration
  24322. (handlers (list (dicod-handler
  24323. (name "wordnet")
  24324. (module "dictorg")
  24325. (options
  24326. (list #~(string-append "dbdir=" #$wordnet))))))
  24327. (databases (list (dicod-database
  24328. (name "wordnet")
  24329. (complex? #t)
  24330. (handler "wordnet")
  24331. (options '("database=wn")))
  24332. %dicod-database:gcide))))
  24333. @end lisp
  24334. @cindex Docker
  24335. @subsubheading Docker Service
  24336. The @code{(gnu services docker)} module provides the following services.
  24337. @defvr {Scheme Variable} docker-service-type
  24338. This is the type of the service that runs @url{https://www.docker.com,Docker},
  24339. a daemon that can execute application bundles (sometimes referred to as
  24340. ``containers'') in isolated environments.
  24341. @end defvr
  24342. @deftp {Data Type} docker-configuration
  24343. This is the data type representing the configuration of Docker and Containerd.
  24344. @table @asis
  24345. @item @code{package} (default: @code{docker})
  24346. The Docker daemon package to use.
  24347. @item @code{package} (default: @code{docker-cli})
  24348. The Docker client package to use.
  24349. @item @code{containerd} (default: @var{containerd})
  24350. The Containerd package to use.
  24351. @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
  24352. The Docker user-land networking proxy package to use.
  24353. @item @code{enable-proxy?} (default @code{#t})
  24354. Enable or disable the use of the Docker user-land networking proxy.
  24355. @item @code{debug?} (default @code{#f})
  24356. Enable or disable debug output.
  24357. @item @code{enable-iptables?} (default @code{#t})
  24358. Enable or disable the addition of iptables rules.
  24359. @end table
  24360. @end deftp
  24361. @cindex Singularity, container service
  24362. @defvr {Scheme Variable} singularity-service-type
  24363. This is the type of the service that allows you to run
  24364. @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
  24365. create and run application bundles (aka. ``containers''). The value for this
  24366. service is the Singularity package to use.
  24367. The service does not install a daemon; instead, it installs helper programs as
  24368. setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
  24369. @command{singularity run} and similar commands.
  24370. @end defvr
  24371. @cindex Audit
  24372. @subsubheading Auditd Service
  24373. The @code{(gnu services auditd)} module provides the following service.
  24374. @defvr {Scheme Variable} auditd-service-type
  24375. This is the type of the service that runs
  24376. @url{https://people.redhat.com/sgrubb/audit/,auditd},
  24377. a daemon that tracks security-relevant information on your system.
  24378. Examples of things that can be tracked:
  24379. @enumerate
  24380. @item
  24381. File accesses
  24382. @item
  24383. System calls
  24384. @item
  24385. Invoked commands
  24386. @item
  24387. Failed login attempts
  24388. @item
  24389. Firewall filtering
  24390. @item
  24391. Network access
  24392. @end enumerate
  24393. @command{auditctl} from the @code{audit} package can be used in order
  24394. to add or remove events to be tracked (until the next reboot).
  24395. In order to permanently track events, put the command line arguments
  24396. of auditctl into a file called @code{audit.rules} in the configuration
  24397. directory (see below).
  24398. @command{aureport} from the @code{audit} package can be used in order
  24399. to view a report of all recorded events.
  24400. The audit daemon by default logs into the file
  24401. @file{/var/log/audit.log}.
  24402. @end defvr
  24403. @deftp {Data Type} auditd-configuration
  24404. This is the data type representing the configuration of auditd.
  24405. @table @asis
  24406. @item @code{audit} (default: @code{audit})
  24407. The audit package to use.
  24408. @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
  24409. The directory containing the configuration file for the audit package, which
  24410. must be named @code{auditd.conf}, and optionally some audit rules to
  24411. instantiate on startup.
  24412. @end table
  24413. @end deftp
  24414. @cindex rshiny
  24415. @subsubheading R-Shiny service
  24416. The @code{(gnu services science)} module provides the following service.
  24417. @defvr {Scheme Variable} rshiny-service-type
  24418. This is a type of service which is used to run a webapp created with
  24419. @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
  24420. variable and runs the provided script to call @code{runApp}.
  24421. @deftp {Data Type} rshiny-configuration
  24422. This is the data type representing the configuration of rshiny.
  24423. @table @asis
  24424. @item @code{package} (default: @code{r-shiny})
  24425. The package to use.
  24426. @item @code{binary} (defaunlt @code{"rshiny"})
  24427. The name of the binary or shell script located at @code{package/bin/} to
  24428. run when the service is run.
  24429. The common way to create this file is as follows:
  24430. @lisp
  24431. @dots{}
  24432. (let* ((out (assoc-ref %outputs "out"))
  24433. (targetdir (string-append out "/share/" ,name))
  24434. (app (string-append out "/bin/" ,name))
  24435. (Rbin (string-append (assoc-ref %build-inputs "r-min")
  24436. "/bin/Rscript")))
  24437. ;; @dots{}
  24438. (mkdir-p (string-append out "/bin"))
  24439. (call-with-output-file app
  24440. (lambda (port)
  24441. (format port
  24442. "#!~a
  24443. library(shiny)
  24444. setwd(\"~a\")
  24445. runApp(launch.browser=0, port=4202)~%\n"
  24446. Rbin targetdir))))
  24447. @end lisp
  24448. @end table
  24449. @end deftp
  24450. @end defvr
  24451. @cindex Nix
  24452. @subsubheading Nix service
  24453. The @code{(gnu services nix)} module provides the following service.
  24454. @defvr {Scheme Variable} nix-service-type
  24455. This is the type of the service that runs build daemon of the
  24456. @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
  24457. how to use it:
  24458. @lisp
  24459. (use-modules (gnu))
  24460. (use-service-modules nix)
  24461. (use-package-modules package-management)
  24462. (operating-system
  24463. ;; @dots{}
  24464. (packages (append (list nix)
  24465. %base-packages))
  24466. (services (append (list (service nix-service-type))
  24467. %base-services)))
  24468. @end lisp
  24469. After @command{guix system reconfigure} configure Nix for your user:
  24470. @itemize
  24471. @item Add a Nix channel and update it. See
  24472. @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
  24473. @item Create a symlink to your profile and activate Nix profile:
  24474. @end itemize
  24475. @example
  24476. $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
  24477. $ source /run/current-system/profile/etc/profile.d/nix.sh
  24478. @end example
  24479. @end defvr
  24480. @deftp {Data Type} nix-configuration
  24481. This data type represents the configuration of the Nix daemon.
  24482. @table @asis
  24483. @item @code{nix} (default: @code{nix})
  24484. The Nix package to use.
  24485. @item @code{sandbox} (default: @code{#t})
  24486. Specifies whether builds are sandboxed by default.
  24487. @item @code{build-sandbox-items} (default: @code{'()})
  24488. This is a list of strings or objects appended to the
  24489. @code{build-sandbox-items} field of the configuration file.
  24490. @item @code{extra-config} (default: @code{'()})
  24491. This is a list of strings or objects appended to the configuration file.
  24492. It is used to pass extra text to be added verbatim to the configuration
  24493. file.
  24494. @item @code{extra-options} (default: @code{'()})
  24495. Extra command line options for @code{nix-service-type}.
  24496. @end table
  24497. @end deftp
  24498. @node Setuid Programs
  24499. @section Setuid Programs
  24500. @cindex setuid programs
  24501. Some programs need to run with ``root'' privileges, even when they are
  24502. launched by unprivileged users. A notorious example is the
  24503. @command{passwd} program, which users can run to change their
  24504. password, and which needs to access the @file{/etc/passwd} and
  24505. @file{/etc/shadow} files---something normally restricted to root, for
  24506. obvious security reasons. To address that, these executables are
  24507. @dfn{setuid-root}, meaning that they always run with root privileges
  24508. (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
  24509. for more info about the setuid mechanism).
  24510. The store itself @emph{cannot} contain setuid programs: that would be a
  24511. security issue since any user on the system can write derivations that
  24512. populate the store (@pxref{The Store}). Thus, a different mechanism is
  24513. used: instead of changing the setuid bit directly on files that are in
  24514. the store, we let the system administrator @emph{declare} which programs
  24515. should be setuid root.
  24516. The @code{setuid-programs} field of an @code{operating-system}
  24517. declaration contains a list of G-expressions denoting the names of
  24518. programs to be setuid-root (@pxref{Using the Configuration System}).
  24519. For instance, the @command{passwd} program, which is part of the Shadow
  24520. package, can be designated by this G-expression (@pxref{G-Expressions}):
  24521. @example
  24522. #~(string-append #$shadow "/bin/passwd")
  24523. @end example
  24524. A default set of setuid programs is defined by the
  24525. @code{%setuid-programs} variable of the @code{(gnu system)} module.
  24526. @defvr {Scheme Variable} %setuid-programs
  24527. A list of G-expressions denoting common programs that are setuid-root.
  24528. The list includes commands such as @command{passwd}, @command{ping},
  24529. @command{su}, and @command{sudo}.
  24530. @end defvr
  24531. Under the hood, the actual setuid programs are created in the
  24532. @file{/run/setuid-programs} directory at system activation time. The
  24533. files in this directory refer to the ``real'' binaries, which are in the
  24534. store.
  24535. @node X.509 Certificates
  24536. @section X.509 Certificates
  24537. @cindex HTTPS, certificates
  24538. @cindex X.509 certificates
  24539. @cindex TLS
  24540. Web servers available over HTTPS (that is, HTTP over the transport-layer
  24541. security mechanism, TLS) send client programs an @dfn{X.509 certificate}
  24542. that the client can then use to @emph{authenticate} the server. To do
  24543. that, clients verify that the server's certificate is signed by a
  24544. so-called @dfn{certificate authority} (CA). But to verify the CA's
  24545. signature, clients must have first acquired the CA's certificate.
  24546. Web browsers such as GNU@tie{}IceCat include their own set of CA
  24547. certificates, such that they are able to verify CA signatures
  24548. out-of-the-box.
  24549. However, most other programs that can talk HTTPS---@command{wget},
  24550. @command{git}, @command{w3m}, etc.---need to be told where CA
  24551. certificates can be found.
  24552. @cindex @code{nss-certs}
  24553. In Guix, this is done by adding a package that provides certificates
  24554. to the @code{packages} field of the @code{operating-system} declaration
  24555. (@pxref{operating-system Reference}). Guix includes one such package,
  24556. @code{nss-certs}, which is a set of CA certificates provided as part of
  24557. Mozilla's Network Security Services.
  24558. Note that it is @emph{not} part of @code{%base-packages}, so you need to
  24559. explicitly add it. The @file{/etc/ssl/certs} directory, which is where
  24560. most applications and libraries look for certificates by default, points
  24561. to the certificates installed globally.
  24562. Unprivileged users, including users of Guix on a foreign distro,
  24563. can also install their own certificate package in
  24564. their profile. A number of environment variables need to be defined so
  24565. that applications and libraries know where to find them. Namely, the
  24566. OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
  24567. variables. Some applications add their own environment variables; for
  24568. instance, the Git version control system honors the certificate bundle
  24569. pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
  24570. would typically run something like:
  24571. @example
  24572. guix install nss-certs
  24573. export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
  24574. export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
  24575. export GIT_SSL_CAINFO="$SSL_CERT_FILE"
  24576. @end example
  24577. As another example, R requires the @env{CURL_CA_BUNDLE} environment
  24578. variable to point to a certificate bundle, so you would have to run
  24579. something like this:
  24580. @example
  24581. guix install nss-certs
  24582. export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
  24583. @end example
  24584. For other applications you may want to look up the required environment
  24585. variable in the relevant documentation.
  24586. @node Name Service Switch
  24587. @section Name Service Switch
  24588. @cindex name service switch
  24589. @cindex NSS
  24590. The @code{(gnu system nss)} module provides bindings to the
  24591. configuration file of the libc @dfn{name service switch} or @dfn{NSS}
  24592. (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
  24593. Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
  24594. extended with new ``name'' lookup methods for system databases, which
  24595. includes host names, service names, user accounts, and more (@pxref{Name
  24596. Service Switch, System Databases and Name Service Switch,, libc, The GNU
  24597. C Library Reference Manual}).
  24598. The NSS configuration specifies, for each system database, which lookup
  24599. method is to be used, and how the various methods are chained
  24600. together---for instance, under which circumstances NSS should try the
  24601. next method in the list. The NSS configuration is given in the
  24602. @code{name-service-switch} field of @code{operating-system} declarations
  24603. (@pxref{operating-system Reference, @code{name-service-switch}}).
  24604. @cindex nss-mdns
  24605. @cindex .local, host name lookup
  24606. As an example, the declaration below configures the NSS to use the
  24607. @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
  24608. back-end}, which supports host name lookups over multicast DNS (mDNS)
  24609. for host names ending in @code{.local}:
  24610. @lisp
  24611. (name-service-switch
  24612. (hosts (list %files ;first, check /etc/hosts
  24613. ;; If the above did not succeed, try
  24614. ;; with 'mdns_minimal'.
  24615. (name-service
  24616. (name "mdns_minimal")
  24617. ;; 'mdns_minimal' is authoritative for
  24618. ;; '.local'. When it returns "not found",
  24619. ;; no need to try the next methods.
  24620. (reaction (lookup-specification
  24621. (not-found => return))))
  24622. ;; Then fall back to DNS.
  24623. (name-service
  24624. (name "dns"))
  24625. ;; Finally, try with the "full" 'mdns'.
  24626. (name-service
  24627. (name "mdns")))))
  24628. @end lisp
  24629. Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
  24630. contains this configuration, so you will not have to type it if all you
  24631. want is to have @code{.local} host lookup working.
  24632. Note that, in this case, in addition to setting the
  24633. @code{name-service-switch} of the @code{operating-system} declaration,
  24634. you also need to use @code{avahi-service-type} (@pxref{Networking Services,
  24635. @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
  24636. (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
  24637. to the name service cache daemon (@pxref{Base Services,
  24638. @code{nscd-service}}).
  24639. For convenience, the following variables provide typical NSS
  24640. configurations.
  24641. @defvr {Scheme Variable} %default-nss
  24642. This is the default name service switch configuration, a
  24643. @code{name-service-switch} object.
  24644. @end defvr
  24645. @defvr {Scheme Variable} %mdns-host-lookup-nss
  24646. This is the name service switch configuration with support for host name
  24647. lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
  24648. @end defvr
  24649. The reference for name service switch configuration is given below. It
  24650. is a direct mapping of the configuration file format of the C library , so
  24651. please refer to the C library manual for more information (@pxref{NSS
  24652. Configuration File,,, libc, The GNU C Library Reference Manual}).
  24653. Compared to the configuration file format of libc NSS, it has the advantage
  24654. not only of adding this warm parenthetic feel that we like, but also
  24655. static checks: you will know about syntax errors and typos as soon as you
  24656. run @command{guix system}.
  24657. @deftp {Data Type} name-service-switch
  24658. This is the data type representation the configuration of libc's name
  24659. service switch (NSS). Each field below represents one of the supported
  24660. system databases.
  24661. @table @code
  24662. @item aliases
  24663. @itemx ethers
  24664. @itemx group
  24665. @itemx gshadow
  24666. @itemx hosts
  24667. @itemx initgroups
  24668. @itemx netgroup
  24669. @itemx networks
  24670. @itemx password
  24671. @itemx public-key
  24672. @itemx rpc
  24673. @itemx services
  24674. @itemx shadow
  24675. The system databases handled by the NSS@. Each of these fields must be a
  24676. list of @code{<name-service>} objects (see below).
  24677. @end table
  24678. @end deftp
  24679. @deftp {Data Type} name-service
  24680. This is the data type representing an actual name service and the
  24681. associated lookup action.
  24682. @table @code
  24683. @item name
  24684. A string denoting the name service (@pxref{Services in the NSS
  24685. configuration,,, libc, The GNU C Library Reference Manual}).
  24686. Note that name services listed here must be visible to nscd. This is
  24687. achieved by passing the @code{#:name-services} argument to
  24688. @code{nscd-service} the list of packages providing the needed name
  24689. services (@pxref{Base Services, @code{nscd-service}}).
  24690. @item reaction
  24691. An action specified using the @code{lookup-specification} macro
  24692. (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
  24693. Reference Manual}). For example:
  24694. @lisp
  24695. (lookup-specification (unavailable => continue)
  24696. (success => return))
  24697. @end lisp
  24698. @end table
  24699. @end deftp
  24700. @node Initial RAM Disk
  24701. @section Initial RAM Disk
  24702. @cindex initrd
  24703. @cindex initial RAM disk
  24704. For bootstrapping purposes, the Linux-Libre kernel is passed an
  24705. @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
  24706. root file system as well as an initialization script. The latter is
  24707. responsible for mounting the real root file system, and for loading any
  24708. kernel modules that may be needed to achieve that.
  24709. The @code{initrd-modules} field of an @code{operating-system}
  24710. declaration allows you to specify Linux-libre kernel modules that must
  24711. be available in the initrd. In particular, this is where you would list
  24712. modules needed to actually drive the hard disk where your root partition
  24713. is---although the default value of @code{initrd-modules} should cover
  24714. most use cases. For example, assuming you need the @code{megaraid_sas}
  24715. module in addition to the default modules to be able to access your root
  24716. file system, you would write:
  24717. @lisp
  24718. (operating-system
  24719. ;; @dots{}
  24720. (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
  24721. @end lisp
  24722. @defvr {Scheme Variable} %base-initrd-modules
  24723. This is the list of kernel modules included in the initrd by default.
  24724. @end defvr
  24725. Furthermore, if you need lower-level customization, the @code{initrd}
  24726. field of an @code{operating-system} declaration allows
  24727. you to specify which initrd you would like to use. The @code{(gnu
  24728. system linux-initrd)} module provides three ways to build an initrd: the
  24729. high-level @code{base-initrd} procedure and the low-level
  24730. @code{raw-initrd} and @code{expression->initrd} procedures.
  24731. The @code{base-initrd} procedure is intended to cover most common uses.
  24732. For example, if you want to add a bunch of kernel modules to be loaded
  24733. at boot time, you can define the @code{initrd} field of the operating
  24734. system declaration like this:
  24735. @lisp
  24736. (initrd (lambda (file-systems . rest)
  24737. ;; Create a standard initrd but set up networking
  24738. ;; with the parameters QEMU expects by default.
  24739. (apply base-initrd file-systems
  24740. #:qemu-networking? #t
  24741. rest)))
  24742. @end lisp
  24743. The @code{base-initrd} procedure also handles common use cases that
  24744. involves using the system as a QEMU guest, or as a ``live'' system with
  24745. volatile root file system.
  24746. The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
  24747. Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
  24748. such as trying to guess which kernel modules and packages should be included
  24749. to the initrd. An example use of @code{raw-initrd} is when a user has
  24750. a custom Linux kernel configuration and default kernel modules included by
  24751. @code{base-initrd} are not available.
  24752. The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
  24753. honors several options passed on the Linux kernel command line
  24754. (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
  24755. @code{-append} option of QEMU), notably:
  24756. @table @code
  24757. @item --load=@var{boot}
  24758. Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
  24759. program, once it has mounted the root file system.
  24760. Guix uses this option to yield control to a boot program that runs the
  24761. service activation programs and then spawns the GNU@tie{}Shepherd, the
  24762. initialization system.
  24763. @item --root=@var{root}
  24764. Mount @var{root} as the root file system. @var{root} can be a device
  24765. name like @code{/dev/sda1}, a file system label, or a file system UUID.
  24766. When unspecified, the device name from the root file system of the
  24767. operating system declaration is used.
  24768. @item --system=@var{system}
  24769. Have @file{/run/booted-system} and @file{/run/current-system} point to
  24770. @var{system}.
  24771. @item modprobe.blacklist=@var{modules}@dots{}
  24772. @cindex module, black-listing
  24773. @cindex black list, of kernel modules
  24774. Instruct the initial RAM disk as well as the @command{modprobe} command
  24775. (from the kmod package) to refuse to load @var{modules}. @var{modules}
  24776. must be a comma-separated list of module names---e.g.,
  24777. @code{usbkbd,9pnet}.
  24778. @item --repl
  24779. Start a read-eval-print loop (REPL) from the initial RAM disk before it
  24780. tries to load kernel modules and to mount the root file system. Our
  24781. marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
  24782. love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
  24783. Manual}, for more information on Guile's REPL.
  24784. @end table
  24785. Now that you know all the features that initial RAM disks produced by
  24786. @code{base-initrd} and @code{raw-initrd} provide,
  24787. here is how to use it and customize it further.
  24788. @cindex initrd
  24789. @cindex initial RAM disk
  24790. @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
  24791. [#:linux-modules '()] [#:mapped-devices '()] @
  24792. [#:keyboard-layout #f] @
  24793. [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
  24794. Return a derivation that builds a raw initrd. @var{file-systems} is
  24795. a list of file systems to be mounted by the initrd, possibly in addition to
  24796. the root file system specified on the kernel command line via @option{--root}.
  24797. @var{linux-modules} is a list of kernel modules to be loaded at boot time.
  24798. @var{mapped-devices} is a list of device mappings to realize before
  24799. @var{file-systems} are mounted (@pxref{Mapped Devices}).
  24800. @var{helper-packages} is a list of packages to be copied in the initrd.
  24801. It may
  24802. include @code{e2fsck/static} or other packages needed by the initrd to check
  24803. the root file system.
  24804. When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
  24805. the desired console keyboard layout. This is done before @var{mapped-devices}
  24806. are set up and before @var{file-systems} are mounted such that, should the
  24807. user need to enter a passphrase or use the REPL, this happens using the
  24808. intended keyboard layout.
  24809. When @var{qemu-networking?} is true, set up networking with the standard QEMU
  24810. parameters. When @var{virtio?} is true, load additional modules so that the
  24811. initrd can be used as a QEMU guest with para-virtualized I/O drivers.
  24812. When @var{volatile-root?} is true, the root file system is writable but any changes
  24813. to it are lost.
  24814. @end deffn
  24815. @deffn {Scheme Procedure} base-initrd @var{file-systems} @
  24816. [#:mapped-devices '()] [#:keyboard-layout #f] @
  24817. [#:qemu-networking? #f] [#:volatile-root? #f] @
  24818. [#:linux-modules '()]
  24819. Return as a file-like object a generic initrd, with kernel
  24820. modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
  24821. mounted by the initrd, possibly in addition to the root file system specified
  24822. on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
  24823. mappings to realize before @var{file-systems} are mounted.
  24824. When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
  24825. the desired console keyboard layout. This is done before @var{mapped-devices}
  24826. are set up and before @var{file-systems} are mounted such that, should the
  24827. user need to enter a passphrase or use the REPL, this happens using the
  24828. intended keyboard layout.
  24829. @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
  24830. The initrd is automatically populated with all the kernel modules necessary
  24831. for @var{file-systems} and for the given options. Additional kernel
  24832. modules can be listed in @var{linux-modules}. They will be added to the initrd, and
  24833. loaded at boot time in the order in which they appear.
  24834. @end deffn
  24835. Needless to say, the initrds we produce and use embed a
  24836. statically-linked Guile, and the initialization program is a Guile
  24837. program. That gives a lot of flexibility. The
  24838. @code{expression->initrd} procedure builds such an initrd, given the
  24839. program to run in that initrd.
  24840. @deffn {Scheme Procedure} expression->initrd @var{exp} @
  24841. [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
  24842. Return as a file-like object a Linux initrd (a gzipped cpio archive)
  24843. containing @var{guile} and that evaluates @var{exp}, a G-expression,
  24844. upon booting. All the derivations referenced by @var{exp} are
  24845. automatically copied to the initrd.
  24846. @end deffn
  24847. @node Bootloader Configuration
  24848. @section Bootloader Configuration
  24849. @cindex bootloader
  24850. @cindex boot loader
  24851. The operating system supports multiple bootloaders. The bootloader is
  24852. configured using @code{bootloader-configuration} declaration. All the
  24853. fields of this structure are bootloader agnostic except for one field,
  24854. @code{bootloader} that indicates the bootloader to be configured and
  24855. installed.
  24856. Some of the bootloaders do not honor every field of
  24857. @code{bootloader-configuration}. For instance, the extlinux
  24858. bootloader does not support themes and thus ignores the @code{theme}
  24859. field.
  24860. @deftp {Data Type} bootloader-configuration
  24861. The type of a bootloader configuration declaration.
  24862. @table @asis
  24863. @item @code{bootloader}
  24864. @cindex EFI, bootloader
  24865. @cindex UEFI, bootloader
  24866. @cindex BIOS, bootloader
  24867. The bootloader to use, as a @code{bootloader} object. For now
  24868. @code{grub-bootloader}, @code{grub-efi-bootloader},
  24869. @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
  24870. @code{u-boot-bootloader} are supported.
  24871. @cindex ARM, bootloaders
  24872. @cindex AArch64, bootloaders
  24873. Available bootloaders are described in @code{(gnu bootloader @dots{})}
  24874. modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
  24875. of bootloaders for a wide range of ARM and AArch64 systems, using the
  24876. @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
  24877. @vindex grub-efi-bootloader
  24878. @code{grub-efi-bootloader} allows to boot on modern systems using the
  24879. @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
  24880. use if the installation image contains a @file{/sys/firmware/efi} directory
  24881. when you boot it on your system.
  24882. @vindex grub-bootloader
  24883. @code{grub-bootloader} allows you to boot in particular Intel-based machines
  24884. in ``legacy'' BIOS mode.
  24885. @vindex grub-efi-netboot-bootloader
  24886. @code{grub-efi-netboot-bootloader} allows you to boot your system over network
  24887. through TFTP@. In combination with an NFS root file system this allows you to
  24888. build a diskless Guix system.
  24889. The installation of the @code{grub-efi-netboot-bootloader} generates the content
  24890. of the TFTP root directory at @code{target}
  24891. (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
  24892. You may want to mount your TFTP server directory onto @code{target} to move the
  24893. required files to the TFTP server automatically.
  24894. If you plan to use an NFS root file system as well (actually if you mount the
  24895. store from an NFS share), then the TFTP server needs to serve the file
  24896. @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
  24897. image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
  24898. initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
  24899. files from the store will be accessed by GRUB through TFTP with their normal
  24900. store path, for example as
  24901. @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
  24902. Two symlinks are created to make this possible. The first symlink is
  24903. @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
  24904. @file{../../../boot/grub/grub.cfg},
  24905. where @code{target} may be @file{/boot}. In this case the link is not leaving
  24906. the served TFTP root directory, but otherwise it does. The second link is
  24907. @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
  24908. is leaving the served TFTP root directory.
  24909. The assumption behind all this is that you have an NFS server exporting the root
  24910. file system for your Guix system, and additionally a TFTP server exporting your
  24911. @code{target} directory—usually @file{/boot}—from that same root file system for
  24912. your Guix system. In this constellation the symlinks will work.
  24913. For other constellations you will have to program your own bootloader installer,
  24914. which then takes care to make necessary files from the store accessible through
  24915. TFTP, for example by copying them into the TFTP root directory at @code{target}.
  24916. It is important to note that symlinks pointing outside the TFTP root directory
  24917. may need to be allowed in the configuration of your TFTP server. Further the
  24918. store link exposes the whole store through TFTP@. Both points need to be
  24919. considered carefully for security aspects.
  24920. Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
  24921. NFS servers, you also need a properly configured DHCP server to make the booting
  24922. over netboot possible. For all this we can currently only recommend you to look
  24923. for instructions about @acronym{PXE, Preboot eXecution Environment}.
  24924. @item @code{target}
  24925. This is a string denoting the target onto which to install the
  24926. bootloader.
  24927. The interpretation depends on the bootloader in question. For
  24928. @code{grub-bootloader}, for example, it should be a device name understood by
  24929. the bootloader @command{installer} command, such as @code{/dev/sda} or
  24930. @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
  24931. @code{grub-efi-bootloader}, it should be the mount point of the EFI file
  24932. system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
  24933. @code{target} should be the mount point corresponding to the TFTP root
  24934. directory of your TFTP server.
  24935. @item @code{menu-entries} (default: @code{()})
  24936. A possibly empty list of @code{menu-entry} objects (see below), denoting
  24937. entries to appear in the bootloader menu, in addition to the current
  24938. system entry and the entry pointing to previous system generations.
  24939. @item @code{default-entry} (default: @code{0})
  24940. The index of the default boot menu entry. Index 0 is for the entry of the
  24941. current system.
  24942. @item @code{timeout} (default: @code{5})
  24943. The number of seconds to wait for keyboard input before booting. Set to
  24944. 0 to boot immediately, and to -1 to wait indefinitely.
  24945. @cindex keyboard layout, for the bootloader
  24946. @item @code{keyboard-layout} (default: @code{#f})
  24947. If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
  24948. layout, usually US@tie{}English (``qwerty'').
  24949. Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
  24950. Layout}).
  24951. @quotation Note
  24952. This option is currently ignored by bootloaders other than @code{grub} and
  24953. @code{grub-efi}.
  24954. @end quotation
  24955. @item @code{theme} (default: @var{#f})
  24956. The bootloader theme object describing the theme to use. If no theme
  24957. is provided, some bootloaders might use a default theme, that's true
  24958. for GRUB.
  24959. @item @code{terminal-outputs} (default: @code{'(gfxterm)})
  24960. The output terminals used for the bootloader boot menu, as a list of
  24961. symbols. GRUB accepts the values: @code{console}, @code{serial},
  24962. @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
  24963. @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
  24964. corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
  24965. configuration,,, grub,GNU GRUB manual}).
  24966. @item @code{terminal-inputs} (default: @code{'()})
  24967. The input terminals used for the bootloader boot menu, as a list of
  24968. symbols. For GRUB, the default is the native platform terminal as
  24969. determined at run-time. GRUB accepts the values: @code{console},
  24970. @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
  24971. @code{usb_keyboard}. This field corresponds to the GRUB variable
  24972. @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
  24973. manual}).
  24974. @item @code{serial-unit} (default: @code{#f})
  24975. The serial unit used by the bootloader, as an integer from 0 to 3.
  24976. For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
  24977. corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
  24978. @item @code{serial-speed} (default: @code{#f})
  24979. The speed of the serial interface, as an integer. For GRUB, the
  24980. default value is chosen at run-time; currently GRUB chooses
  24981. 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
  24982. @end table
  24983. @end deftp
  24984. @cindex dual boot
  24985. @cindex boot menu
  24986. Should you want to list additional boot menu entries @i{via} the
  24987. @code{menu-entries} field above, you will need to create them with the
  24988. @code{menu-entry} form. For example, imagine you want to be able to
  24989. boot another distro (hard to imagine!), you can define a menu entry
  24990. along these lines:
  24991. @lisp
  24992. (menu-entry
  24993. (label "The Other Distro")
  24994. (linux "/boot/old/vmlinux-2.6.32")
  24995. (linux-arguments '("root=/dev/sda2"))
  24996. (initrd "/boot/old/initrd"))
  24997. @end lisp
  24998. Details below.
  24999. @deftp {Data Type} menu-entry
  25000. The type of an entry in the bootloader menu.
  25001. @table @asis
  25002. @item @code{label}
  25003. The label to show in the menu---e.g., @code{"GNU"}.
  25004. @item @code{linux} (default: @code{#f})
  25005. The Linux kernel image to boot, for example:
  25006. @lisp
  25007. (file-append linux-libre "/bzImage")
  25008. @end lisp
  25009. For GRUB, it is also possible to specify a device explicitly in the
  25010. file path using GRUB's device naming convention (@pxref{Naming
  25011. convention,,, grub, GNU GRUB manual}), for example:
  25012. @example
  25013. "(hd0,msdos1)/boot/vmlinuz"
  25014. @end example
  25015. If the device is specified explicitly as above, then the @code{device}
  25016. field is ignored entirely.
  25017. @item @code{linux-arguments} (default: @code{()})
  25018. The list of extra Linux kernel command-line arguments---e.g.,
  25019. @code{("console=ttyS0")}.
  25020. @item @code{initrd} (default: @code{#f})
  25021. A G-Expression or string denoting the file name of the initial RAM disk
  25022. to use (@pxref{G-Expressions}).
  25023. @item @code{device} (default: @code{#f})
  25024. The device where the kernel and initrd are to be found---i.e., for GRUB,
  25025. @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
  25026. This may be a file system label (a string), a file system UUID (a
  25027. bytevector, @pxref{File Systems}), or @code{#f}, in which case
  25028. the bootloader will search the device containing the file specified by
  25029. the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
  25030. must @emph{not} be an OS device name such as @file{/dev/sda1}.
  25031. @item @code{multiboot-kernel} (default: @code{#f})
  25032. The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
  25033. manual}). When this field is set, a Multiboot menu-entry is generated.
  25034. For example:
  25035. @lisp
  25036. (file-append mach "/boot/gnumach")
  25037. @end lisp
  25038. @item @code{multiboot-arguments} (default: @code{()})
  25039. The list of extra command-line arguments for the multiboot-kernel.
  25040. @item @code{multiboot-modules} (default: @code{()})
  25041. The list of commands for loading Multiboot modules. For example:
  25042. @lisp
  25043. (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
  25044. @dots{})
  25045. (list (file-append libc "/lib/ld.so.1") "exec"
  25046. @dots{}))
  25047. @end lisp
  25048. @end table
  25049. @end deftp
  25050. @cindex HDPI
  25051. @cindex HiDPI
  25052. @cindex resolution
  25053. @c FIXME: Write documentation once it's stable.
  25054. For now only GRUB has theme support. GRUB themes are created using
  25055. the @code{grub-theme} form, which is not fully documented yet.
  25056. @deftp {Data Type} grub-theme
  25057. Data type representing the configuration of the GRUB theme.
  25058. @table @asis
  25059. @item @code{gfxmode} (default: @code{'("auto")})
  25060. The GRUB @code{gfxmode} to set (a list of screen resolution strings,
  25061. @pxref{gfxmode,,, grub, GNU GRUB manual}).
  25062. @end table
  25063. @end deftp
  25064. @deffn {Scheme Procedure} grub-theme
  25065. Return the default GRUB theme used by the operating system if no
  25066. @code{theme} field is specified in @code{bootloader-configuration}
  25067. record.
  25068. It comes with a fancy background image displaying the GNU and Guix
  25069. logos.
  25070. @end deffn
  25071. For example, to override the default resolution, you may use something
  25072. like
  25073. @lisp
  25074. (bootloader
  25075. (bootloader-configuration
  25076. ;; @dots{}
  25077. (theme (grub-theme
  25078. (inherit (grub-theme))
  25079. (gfxmode '("1024x786x32" "auto"))))))
  25080. @end lisp
  25081. @node Invoking guix system
  25082. @section Invoking @code{guix system}
  25083. Once you have written an operating system declaration as seen in the
  25084. previous section, it can be @dfn{instantiated} using the @command{guix
  25085. system} command. The synopsis is:
  25086. @example
  25087. guix system @var{options}@dots{} @var{action} @var{file}
  25088. @end example
  25089. @var{file} must be the name of a file containing an
  25090. @code{operating-system} declaration. @var{action} specifies how the
  25091. operating system is instantiated. Currently the following values are
  25092. supported:
  25093. @table @code
  25094. @item search
  25095. Display available service type definitions that match the given regular
  25096. expressions, sorted by relevance:
  25097. @cindex HDPI
  25098. @cindex HiDPI
  25099. @cindex resolution
  25100. @example
  25101. $ guix system search console
  25102. name: console-fonts
  25103. location: gnu/services/base.scm:806:2
  25104. extends: shepherd-root
  25105. description: Install the given fonts on the specified ttys (fonts are per
  25106. + virtual console on GNU/Linux). The value of this service is a list of
  25107. + tty/font pairs. The font can be the name of a font provided by the `kbd'
  25108. + package or any valid argument to `setfont', as in this example:
  25109. +
  25110. + '(("tty1" . "LatGrkCyr-8x16")
  25111. + ("tty2" . (file-append
  25112. + font-tamzen
  25113. + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
  25114. + ("tty3" . (file-append
  25115. + font-terminus
  25116. + "/share/consolefonts/ter-132n"))) ; for HDPI
  25117. relevance: 9
  25118. name: mingetty
  25119. location: gnu/services/base.scm:1190:2
  25120. extends: shepherd-root
  25121. description: Provide console login using the `mingetty' program.
  25122. relevance: 2
  25123. name: login
  25124. location: gnu/services/base.scm:860:2
  25125. extends: pam
  25126. description: Provide a console log-in service as specified by its
  25127. + configuration value, a `login-configuration' object.
  25128. relevance: 2
  25129. @dots{}
  25130. @end example
  25131. As for @command{guix package --search}, the result is written in
  25132. @code{recutils} format, which makes it easy to filter the output
  25133. (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
  25134. @item reconfigure
  25135. Build the operating system described in @var{file}, activate it, and
  25136. switch to it@footnote{This action (and the related actions
  25137. @code{switch-generation} and @code{roll-back}) are usable only on
  25138. systems already running Guix System.}.
  25139. @quotation Note
  25140. @c The paragraph below refers to the problem discussed at
  25141. @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
  25142. It is highly recommended to run @command{guix pull} once before you run
  25143. @command{guix system reconfigure} for the first time (@pxref{Invoking
  25144. guix pull}). Failing to do that you would see an older version of Guix
  25145. once @command{reconfigure} has completed.
  25146. @end quotation
  25147. This effects all the configuration specified in @var{file}: user
  25148. accounts, system services, global package list, setuid programs, etc.
  25149. The command starts system services specified in @var{file} that are not
  25150. currently running; if a service is currently running this command will
  25151. arrange for it to be upgraded the next time it is stopped (e.g.@: by
  25152. @code{herd stop X} or @code{herd restart X}).
  25153. This command creates a new generation whose number is one greater than
  25154. the current generation (as reported by @command{guix system
  25155. list-generations}). If that generation already exists, it will be
  25156. overwritten. This behavior mirrors that of @command{guix package}
  25157. (@pxref{Invoking guix package}).
  25158. It also adds a bootloader menu entry for the new OS configuration,
  25159. ---unless @option{--no-bootloader} is passed. For GRUB, it moves
  25160. entries for older configurations to a submenu, allowing you to choose
  25161. an older system generation at boot time should you need it.
  25162. @cindex provenance tracking, of the operating system
  25163. Upon completion, the new system is deployed under
  25164. @file{/run/current-system}. This directory contains @dfn{provenance
  25165. meta-data}: the list of channels in use (@pxref{Channels}) and
  25166. @var{file} itself, when available. You can view it by running:
  25167. @example
  25168. guix system describe
  25169. @end example
  25170. This information is useful should you later want to inspect how this
  25171. particular generation was built. In fact, assuming @var{file} is
  25172. self-contained, you can later rebuild generation @var{n} of your
  25173. operating system with:
  25174. @example
  25175. guix time-machine \
  25176. -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
  25177. system reconfigure \
  25178. /var/guix/profiles/system-@var{n}-link/configuration.scm
  25179. @end example
  25180. You can think of it as some sort of built-in version control! Your
  25181. system is not just a binary artifact: @emph{it carries its own source}.
  25182. @xref{Service Reference, @code{provenance-service-type}}, for more
  25183. information on provenance tracking.
  25184. By default, @command{reconfigure} @emph{prevents you from downgrading
  25185. your system}, which could (re)introduce security vulnerabilities and
  25186. also cause problems with ``stateful'' services such as database
  25187. management systems. You can override that behavior by passing
  25188. @option{--allow-downgrades}.
  25189. @item switch-generation
  25190. @cindex generations
  25191. Switch to an existing system generation. This action atomically
  25192. switches the system profile to the specified system generation. It
  25193. also rearranges the system's existing bootloader menu entries. It
  25194. makes the menu entry for the specified system generation the default,
  25195. and it moves the entries for the other generations to a submenu, if
  25196. supported by the bootloader being used. The next time the system
  25197. boots, it will use the specified system generation.
  25198. The bootloader itself is not being reinstalled when using this
  25199. command. Thus, the installed bootloader is used with an updated
  25200. configuration file.
  25201. The target generation can be specified explicitly by its generation
  25202. number. For example, the following invocation would switch to system
  25203. generation 7:
  25204. @example
  25205. guix system switch-generation 7
  25206. @end example
  25207. The target generation can also be specified relative to the current
  25208. generation with the form @code{+N} or @code{-N}, where @code{+3} means
  25209. ``3 generations ahead of the current generation,'' and @code{-1} means
  25210. ``1 generation prior to the current generation.'' When specifying a
  25211. negative value such as @code{-1}, you must precede it with @code{--} to
  25212. prevent it from being parsed as an option. For example:
  25213. @example
  25214. guix system switch-generation -- -1
  25215. @end example
  25216. Currently, the effect of invoking this action is @emph{only} to switch
  25217. the system profile to an existing generation and rearrange the
  25218. bootloader menu entries. To actually start using the target system
  25219. generation, you must reboot after running this action. In the future,
  25220. it will be updated to do the same things as @command{reconfigure},
  25221. like activating and deactivating services.
  25222. This action will fail if the specified generation does not exist.
  25223. @item roll-back
  25224. @cindex rolling back
  25225. Switch to the preceding system generation. The next time the system
  25226. boots, it will use the preceding system generation. This is the inverse
  25227. of @command{reconfigure}, and it is exactly the same as invoking
  25228. @command{switch-generation} with an argument of @code{-1}.
  25229. Currently, as with @command{switch-generation}, you must reboot after
  25230. running this action to actually start using the preceding system
  25231. generation.
  25232. @item delete-generations
  25233. @cindex deleting system generations
  25234. @cindex saving space
  25235. Delete system generations, making them candidates for garbage collection
  25236. (@pxref{Invoking guix gc}, for information on how to run the ``garbage
  25237. collector'').
  25238. This works in the same way as @samp{guix package --delete-generations}
  25239. (@pxref{Invoking guix package, @option{--delete-generations}}). With no
  25240. arguments, all system generations but the current one are deleted:
  25241. @example
  25242. guix system delete-generations
  25243. @end example
  25244. You can also select the generations you want to delete. The example below
  25245. deletes all the system generations that are more than two month old:
  25246. @example
  25247. guix system delete-generations 2m
  25248. @end example
  25249. Running this command automatically reinstalls the bootloader with an updated
  25250. list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
  25251. longer lists the generations that have been deleted.
  25252. @item build
  25253. Build the derivation of the operating system, which includes all the
  25254. configuration files and programs needed to boot and run the system.
  25255. This action does not actually install anything.
  25256. @item init
  25257. Populate the given directory with all the files necessary to run the
  25258. operating system specified in @var{file}. This is useful for first-time
  25259. installations of Guix System. For instance:
  25260. @example
  25261. guix system init my-os-config.scm /mnt
  25262. @end example
  25263. copies to @file{/mnt} all the store items required by the configuration
  25264. specified in @file{my-os-config.scm}. This includes configuration
  25265. files, packages, and so on. It also creates other essential files
  25266. needed for the system to operate correctly---e.g., the @file{/etc},
  25267. @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
  25268. This command also installs bootloader on the target specified in
  25269. @file{my-os-config}, unless the @option{--no-bootloader} option was
  25270. passed.
  25271. @item vm
  25272. @cindex virtual machine
  25273. @cindex VM
  25274. @anchor{guix system vm}
  25275. Build a virtual machine that contains the operating system declared in
  25276. @var{file}, and return a script to run that virtual machine (VM).
  25277. @quotation Note
  25278. The @code{vm} action and others below
  25279. can use KVM support in the Linux-libre kernel. Specifically, if the
  25280. machine has hardware virtualization support, the corresponding
  25281. KVM kernel module should be loaded, and the @file{/dev/kvm} device node
  25282. must exist and be readable and writable by the user and by the
  25283. build users of the daemon (@pxref{Build Environment Setup}).
  25284. @end quotation
  25285. Arguments given to the script are passed to QEMU as in the example
  25286. below, which enables networking and requests 1@tie{}GiB of RAM for the
  25287. emulated machine:
  25288. @example
  25289. $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
  25290. @end example
  25291. The VM shares its store with the host system.
  25292. Additional file systems can be shared between the host and the VM using
  25293. the @option{--share} and @option{--expose} command-line options: the former
  25294. specifies a directory to be shared with write access, while the latter
  25295. provides read-only access to the shared directory.
  25296. The example below creates a VM in which the user's home directory is
  25297. accessible read-only, and where the @file{/exchange} directory is a
  25298. read-write mapping of @file{$HOME/tmp} on the host:
  25299. @example
  25300. guix system vm my-config.scm \
  25301. --expose=$HOME --share=$HOME/tmp=/exchange
  25302. @end example
  25303. On GNU/Linux, the default is to boot directly to the kernel; this has
  25304. the advantage of requiring only a very tiny root disk image since the
  25305. store of the host can then be mounted.
  25306. The @option{--full-boot} option forces a complete boot sequence, starting
  25307. with the bootloader. This requires more disk space since a root image
  25308. containing at least the kernel, initrd, and bootloader data files must
  25309. be created. The @option{--image-size} option can be used to specify the
  25310. size of the image.
  25311. @cindex System images, creation in various formats
  25312. @cindex Creating system images in various formats
  25313. @item vm-image
  25314. @itemx image
  25315. @itemx docker-image
  25316. Return a virtual machine, disk image, or Docker image of the operating
  25317. system declared in @var{file} that stands alone. By default,
  25318. @command{guix system} estimates the size of the image needed to store
  25319. the system, but you can use the @option{--image-size} option to specify
  25320. a value. Docker images are built to contain exactly what they need, so
  25321. the @option{--image-size} option is ignored in the case of
  25322. @code{docker-image}.
  25323. @cindex image, creating disk images
  25324. The @code{image} command can produce various image types. The
  25325. image type can be selected using the @option{--image-type} option. It
  25326. defaults to @code{efi-raw}. When its value is @code{iso9660}, the
  25327. @option{--label} option can be used to specify a volume ID with
  25328. @code{image}. By default, the root file system of a disk image is
  25329. mounted non-volatile; the @option{--volatile} option can be provided to
  25330. make it volatile instead. When using @code{image}, the bootloader
  25331. installed on the generated image is taken from the provided
  25332. @code{operating-system} definition. The following example demonstrates
  25333. how to generate an image that uses the @code{grub-efi-bootloader}
  25334. bootloader and boot it with QEMU:
  25335. @example
  25336. image=$(guix system image --image-type=qcow2 \
  25337. gnu/system/examples/lightweight-desktop.tmpl)
  25338. cp $image /tmp/my-image.qcow2
  25339. chmod +w /tmp/my-image.qcow2
  25340. qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
  25341. -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
  25342. @end example
  25343. When using the @code{efi-raw} image type, a raw disk image is produced;
  25344. it can be copied as is to a USB stick, for instance. Assuming
  25345. @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
  25346. the image to it using the following command:
  25347. @example
  25348. # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
  25349. @end example
  25350. The @code{--list-image-types} command lists all the available image
  25351. types.
  25352. @cindex vm-image, creating virtual machine images
  25353. When using @code{vm-image}, the returned image is in qcow2 format, which
  25354. the QEMU emulator can efficiently use. @xref{Running Guix in a VM}, for
  25355. more information on how to run the image in a virtual machine. The
  25356. @code{grub-bootloader} bootloader is always used independently of what
  25357. is declared in the @code{operating-system} file passed as argument.
  25358. This is to make it easier to work with QEMU, which uses the SeaBIOS BIOS
  25359. by default, expecting a bootloader to be installed in the Master Boot
  25360. Record (MBR).
  25361. @cindex docker-image, creating docker images
  25362. When using @code{docker-image}, a Docker image is produced. Guix builds
  25363. the image from scratch, not from a pre-existing Docker base image. As a
  25364. result, it contains @emph{exactly} what you define in the operating
  25365. system configuration file. You can then load the image and launch a
  25366. Docker container using commands like the following:
  25367. @example
  25368. image_id="`docker load < guix-system-docker-image.tar.gz`"
  25369. container_id="`docker create $image_id`"
  25370. docker start $container_id
  25371. @end example
  25372. This command starts a new Docker container from the specified image. It
  25373. will boot the Guix system in the usual manner, which means it will
  25374. start any services you have defined in the operating system
  25375. configuration. You can get an interactive shell running in the container
  25376. using @command{docker exec}:
  25377. @example
  25378. docker exec -ti $container_id /run/current-system/profile/bin/bash --login
  25379. @end example
  25380. Depending on what you run in the Docker container, it
  25381. may be necessary to give the container additional permissions. For
  25382. example, if you intend to build software using Guix inside of the Docker
  25383. container, you may need to pass the @option{--privileged} option to
  25384. @code{docker create}.
  25385. Last, the @option{--network} option applies to @command{guix system
  25386. docker-image}: it produces an image where network is supposedly shared
  25387. with the host, and thus without services like nscd or NetworkManager.
  25388. @item container
  25389. Return a script to run the operating system declared in @var{file}
  25390. within a container. Containers are a set of lightweight isolation
  25391. mechanisms provided by the kernel Linux-libre. Containers are
  25392. substantially less resource-demanding than full virtual machines since
  25393. the kernel, shared objects, and other resources can be shared with the
  25394. host system; this also means they provide thinner isolation.
  25395. Currently, the script must be run as root in order to support more than
  25396. a single user and group. The container shares its store with the host
  25397. system.
  25398. As with the @code{vm} action (@pxref{guix system vm}), additional file
  25399. systems to be shared between the host and container can be specified
  25400. using the @option{--share} and @option{--expose} options:
  25401. @example
  25402. guix system container my-config.scm \
  25403. --expose=$HOME --share=$HOME/tmp=/exchange
  25404. @end example
  25405. @quotation Note
  25406. This option requires Linux-libre 3.19 or newer.
  25407. @end quotation
  25408. @end table
  25409. @var{options} can contain any of the common build options (@pxref{Common
  25410. Build Options}). In addition, @var{options} can contain one of the
  25411. following:
  25412. @table @option
  25413. @item --expression=@var{expr}
  25414. @itemx -e @var{expr}
  25415. Consider the operating-system @var{expr} evaluates to.
  25416. This is an alternative to specifying a file which evaluates to an
  25417. operating system.
  25418. This is used to generate the Guix system installer @pxref{Building the
  25419. Installation Image}).
  25420. @item --system=@var{system}
  25421. @itemx -s @var{system}
  25422. Attempt to build for @var{system} instead of the host system type.
  25423. This works as per @command{guix build} (@pxref{Invoking guix build}).
  25424. @item --derivation
  25425. @itemx -d
  25426. Return the derivation file name of the given operating system without
  25427. building anything.
  25428. @cindex provenance tracking, of the operating system
  25429. @item --save-provenance
  25430. As discussed above, @command{guix system init} and @command{guix system
  25431. reconfigure} always save provenance information @i{via} a dedicated
  25432. service (@pxref{Service Reference, @code{provenance-service-type}}).
  25433. However, other commands don't do that by default. If you wish to, say,
  25434. create a virtual machine image that contains provenance information, you
  25435. can run:
  25436. @example
  25437. guix system vm-image --save-provenance config.scm
  25438. @end example
  25439. That way, the resulting image will effectively ``embed its own source''
  25440. in the form of meta-data in @file{/run/current-system}. With that
  25441. information, one can rebuild the image to make sure it really contains
  25442. what it pretends to contain; or they could use that to derive a variant
  25443. of the image.
  25444. @item --image-type=@var{type}
  25445. @itemx -t @var{type}
  25446. For the @code{image} action, create an image with given @var{type}.
  25447. When this option is omitted, @command{guix system} uses the
  25448. @code{efi-raw} image type.
  25449. @cindex ISO-9660 format
  25450. @cindex CD image format
  25451. @cindex DVD image format
  25452. @option{--image-type=iso9660} produces an ISO-9660 image, suitable
  25453. for burning on CDs and DVDs.
  25454. @item --image-size=@var{size}
  25455. For the @code{vm-image} and @code{image} actions, create an image
  25456. of the given @var{size}. @var{size} may be a number of bytes, or it may
  25457. include a unit as a suffix (@pxref{Block size, size specifications,,
  25458. coreutils, GNU Coreutils}).
  25459. When this option is omitted, @command{guix system} computes an estimate
  25460. of the image size as a function of the size of the system declared in
  25461. @var{file}.
  25462. @item --network
  25463. @itemx -N
  25464. For the @code{container} action, allow containers to access the host network,
  25465. that is, do not create a network namespace.
  25466. @item --root=@var{file}
  25467. @itemx -r @var{file}
  25468. Make @var{file} a symlink to the result, and register it as a garbage
  25469. collector root.
  25470. @item --skip-checks
  25471. Skip pre-installation safety checks.
  25472. By default, @command{guix system init} and @command{guix system
  25473. reconfigure} perform safety checks: they make sure the file systems that
  25474. appear in the @code{operating-system} declaration actually exist
  25475. (@pxref{File Systems}), and that any Linux kernel modules that may be
  25476. needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
  25477. RAM Disk}). Passing this option skips these tests altogether.
  25478. @item --allow-downgrades
  25479. Instruct @command{guix system reconfigure} to allow system downgrades.
  25480. By default, @command{reconfigure} prevents you from downgrading your
  25481. system. It achieves that by comparing the provenance info of your
  25482. system (shown by @command{guix system describe}) with that of your
  25483. @command{guix} command (shown by @command{guix describe}). If the
  25484. commits for @command{guix} are not descendants of those used for your
  25485. system, @command{guix system reconfigure} errors out. Passing
  25486. @option{--allow-downgrades} allows you to bypass these checks.
  25487. @quotation Note
  25488. Make sure you understand its security implications before using
  25489. @option{--allow-downgrades}.
  25490. @end quotation
  25491. @cindex on-error
  25492. @cindex on-error strategy
  25493. @cindex error strategy
  25494. @item --on-error=@var{strategy}
  25495. Apply @var{strategy} when an error occurs when reading @var{file}.
  25496. @var{strategy} may be one of the following:
  25497. @table @code
  25498. @item nothing-special
  25499. Report the error concisely and exit. This is the default strategy.
  25500. @item backtrace
  25501. Likewise, but also display a backtrace.
  25502. @item debug
  25503. Report the error and enter Guile's debugger. From there, you can run
  25504. commands such as @code{,bt} to get a backtrace, @code{,locals} to
  25505. display local variable values, and more generally inspect the state of the
  25506. program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
  25507. a list of available debugging commands.
  25508. @end table
  25509. @end table
  25510. Once you have built, configured, re-configured, and re-re-configured
  25511. your Guix installation, you may find it useful to list the operating
  25512. system generations available on disk---and that you can choose from the
  25513. bootloader boot menu:
  25514. @table @code
  25515. @item describe
  25516. Describe the current system generation: its file name, the kernel and
  25517. bootloader used, etc., as well as provenance information when available.
  25518. @item list-generations
  25519. List a summary of each generation of the operating system available on
  25520. disk, in a human-readable way. This is similar to the
  25521. @option{--list-generations} option of @command{guix package}
  25522. (@pxref{Invoking guix package}).
  25523. Optionally, one can specify a pattern, with the same syntax that is used
  25524. in @command{guix package --list-generations}, to restrict the list of
  25525. generations displayed. For instance, the following command displays
  25526. generations that are up to 10 days old:
  25527. @example
  25528. $ guix system list-generations 10d
  25529. @end example
  25530. @end table
  25531. The @command{guix system} command has even more to offer! The following
  25532. sub-commands allow you to visualize how your system services relate to
  25533. each other:
  25534. @anchor{system-extension-graph}
  25535. @table @code
  25536. @item extension-graph
  25537. Emit to standard output the @dfn{service
  25538. extension graph} of the operating system defined in @var{file}
  25539. (@pxref{Service Composition}, for more information on service
  25540. extensions). By default the output is in Dot/Graphviz format, but you
  25541. can choose a different format with @option{--graph-backend}, as with
  25542. @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
  25543. The command:
  25544. @example
  25545. $ guix system extension-graph @var{file} | xdot -
  25546. @end example
  25547. shows the extension relations among services.
  25548. @anchor{system-shepherd-graph}
  25549. @item shepherd-graph
  25550. Emit to standard output the @dfn{dependency
  25551. graph} of shepherd services of the operating system defined in
  25552. @var{file}. @xref{Shepherd Services}, for more information and for an
  25553. example graph.
  25554. Again, the default output format is Dot/Graphviz, but you can pass
  25555. @option{--graph-backend} to select a different one.
  25556. @end table
  25557. @node Invoking guix deploy
  25558. @section Invoking @code{guix deploy}
  25559. We've already seen @code{operating-system} declarations used to manage a
  25560. machine's configuration locally. Suppose you need to configure multiple
  25561. machines, though---perhaps you're managing a service on the web that's
  25562. comprised of several servers. @command{guix deploy} enables you to use those
  25563. same @code{operating-system} declarations to manage multiple remote hosts at
  25564. once as a logical ``deployment''.
  25565. @quotation Note
  25566. The functionality described in this section is still under development
  25567. and is subject to change. Get in touch with us on
  25568. @email{guix-devel@@gnu.org}!
  25569. @end quotation
  25570. @example
  25571. guix deploy @var{file}
  25572. @end example
  25573. Such an invocation will deploy the machines that the code within @var{file}
  25574. evaluates to. As an example, @var{file} might contain a definition like this:
  25575. @lisp
  25576. ;; This is a Guix deployment of a "bare bones" setup, with
  25577. ;; no X11 display server, to a machine with an SSH daemon
  25578. ;; listening on localhost:2222. A configuration such as this
  25579. ;; may be appropriate for virtual machine with ports
  25580. ;; forwarded to the host's loopback interface.
  25581. (use-service-modules networking ssh)
  25582. (use-package-modules bootloaders)
  25583. (define %system
  25584. (operating-system
  25585. (host-name "gnu-deployed")
  25586. (timezone "Etc/UTC")
  25587. (bootloader (bootloader-configuration
  25588. (bootloader grub-bootloader)
  25589. (target "/dev/vda")
  25590. (terminal-outputs '(console))))
  25591. (file-systems (cons (file-system
  25592. (mount-point "/")
  25593. (device "/dev/vda1")
  25594. (type "ext4"))
  25595. %base-file-systems))
  25596. (services
  25597. (append (list (service dhcp-client-service-type)
  25598. (service openssh-service-type
  25599. (openssh-configuration
  25600. (permit-root-login #t)
  25601. (allow-empty-passwords? #t))))
  25602. %base-services))))
  25603. (list (machine
  25604. (operating-system %system)
  25605. (environment managed-host-environment-type)
  25606. (configuration (machine-ssh-configuration
  25607. (host-name "localhost")
  25608. (system "x86_64-linux")
  25609. (user "alice")
  25610. (identity "./id_rsa")
  25611. (port 2222)))))
  25612. @end lisp
  25613. The file should evaluate to a list of @var{machine} objects. This example,
  25614. upon being deployed, will create a new generation on the remote system
  25615. realizing the @code{operating-system} declaration @code{%system}.
  25616. @code{environment} and @code{configuration} specify how the machine should be
  25617. provisioned---that is, how the computing resources should be created and
  25618. managed. The above example does not create any resources, as a
  25619. @code{'managed-host} is a machine that is already running the Guix system and
  25620. available over the network. This is a particularly simple case; a more
  25621. complex deployment may involve, for example, starting virtual machines through
  25622. a Virtual Private Server (VPS) provider. In such a case, a different
  25623. @var{environment} type would be used.
  25624. Do note that you first need to generate a key pair on the coordinator machine
  25625. to allow the daemon to export signed archives of files from the store
  25626. (@pxref{Invoking guix archive}), though this step is automatic on Guix
  25627. System:
  25628. @example
  25629. # guix archive --generate-key
  25630. @end example
  25631. @noindent
  25632. Each target machine must authorize the key of the master machine so that it
  25633. accepts store items it receives from the coordinator:
  25634. @example
  25635. # guix archive --authorize < coordinator-public-key.txt
  25636. @end example
  25637. @code{user}, in this example, specifies the name of the user account to log in
  25638. as to perform the deployment. Its default value is @code{root}, but root
  25639. login over SSH may be forbidden in some cases. To work around this,
  25640. @command{guix deploy} can log in as an unprivileged user and employ
  25641. @code{sudo} to escalate privileges. This will only work if @code{sudo} is
  25642. currently installed on the remote and can be invoked non-interactively as
  25643. @code{user}. That is, the line in @code{sudoers} granting @code{user} the
  25644. ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
  25645. be accomplished with the following operating system configuration snippet:
  25646. @lisp
  25647. (use-modules ...
  25648. (gnu system)) ;for %sudoers-specification
  25649. (define %user "username")
  25650. (operating-system
  25651. ...
  25652. (sudoers-file
  25653. (plain-file "sudoers"
  25654. (string-append (plain-file-content %sudoers-specification)
  25655. (format #f "~a ALL = NOPASSWD: ALL~%"
  25656. %user)))))
  25657. @end lisp
  25658. For more information regarding the format of the @file{sudoers} file,
  25659. consult @command{man sudoers}.
  25660. @deftp {Data Type} machine
  25661. This is the data type representing a single machine in a heterogeneous Guix
  25662. deployment.
  25663. @table @asis
  25664. @item @code{operating-system}
  25665. The object of the operating system configuration to deploy.
  25666. @item @code{environment}
  25667. An @code{environment-type} describing how the machine should be provisioned.
  25668. @item @code{configuration} (default: @code{#f})
  25669. An object describing the configuration for the machine's @code{environment}.
  25670. If the @code{environment} has a default configuration, @code{#f} may be used.
  25671. If @code{#f} is used for an environment with no default configuration,
  25672. however, an error will be thrown.
  25673. @end table
  25674. @end deftp
  25675. @deftp {Data Type} machine-ssh-configuration
  25676. This is the data type representing the SSH client parameters for a machine
  25677. with an @code{environment} of @code{managed-host-environment-type}.
  25678. @table @asis
  25679. @item @code{host-name}
  25680. @item @code{build-locally?} (default: @code{#t})
  25681. If false, system derivations will be built on the machine being deployed to.
  25682. @item @code{system}
  25683. The system type describing the architecture of the machine being deployed
  25684. to---e.g., @code{"x86_64-linux"}.
  25685. @item @code{authorize?} (default: @code{#t})
  25686. If true, the coordinator's signing key will be added to the remote's ACL
  25687. keyring.
  25688. @item @code{port} (default: @code{22})
  25689. @item @code{user} (default: @code{"root"})
  25690. @item @code{identity} (default: @code{#f})
  25691. If specified, the path to the SSH private key to use to authenticate with the
  25692. remote host.
  25693. @item @code{host-key} (default: @code{#f})
  25694. This should be the SSH host key of the machine, which looks like this:
  25695. @example
  25696. ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
  25697. @end example
  25698. When @code{host-key} is @code{#f}, the server is authenticated against
  25699. the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
  25700. client does.
  25701. @item @code{allow-downgrades?} (default: @code{#f})
  25702. Whether to allow potential downgrades.
  25703. Like @command{guix system reconfigure}, @command{guix deploy} compares
  25704. the channel commits currently deployed on the remote host (as returned
  25705. by @command{guix system describe}) to those currently in use (as
  25706. returned by @command{guix describe}) to determine whether commits
  25707. currently in use are descendants of those deployed. When this is not
  25708. the case and @code{allow-downgrades?} is false, it raises an error.
  25709. This ensures you do not accidentally downgrade remote machines.
  25710. @end table
  25711. @end deftp
  25712. @deftp {Data Type} digital-ocean-configuration
  25713. This is the data type describing the Droplet that should be created for a
  25714. machine with an @code{environment} of @code{digital-ocean-environment-type}.
  25715. @table @asis
  25716. @item @code{ssh-key}
  25717. The path to the SSH private key to use to authenticate with the remote
  25718. host. In the future, this field may not exist.
  25719. @item @code{tags}
  25720. A list of string ``tags'' that uniquely identify the machine. Must be given
  25721. such that no two machines in the deployment have the same set of tags.
  25722. @item @code{region}
  25723. A Digital Ocean region slug, such as @code{"nyc3"}.
  25724. @item @code{size}
  25725. A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
  25726. @item @code{enable-ipv6?}
  25727. Whether or not the droplet should be created with IPv6 networking.
  25728. @end table
  25729. @end deftp
  25730. @node Running Guix in a VM
  25731. @section Running Guix in a Virtual Machine
  25732. @cindex virtual machine
  25733. To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
  25734. distributed at
  25735. @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
  25736. This image is a compressed image in QCOW format. You will first need to
  25737. decompress with @command{xz -d}, and then you can pass it to an emulator such
  25738. as QEMU (see below for details).
  25739. This image boots the Xfce graphical environment and it contains some
  25740. commonly used tools. You can install more software in the image by running
  25741. @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
  25742. also reconfigure the system based on its initial configuration file available
  25743. as @file{/run/current-system/configuration.scm} (@pxref{Using the
  25744. Configuration System}).
  25745. Instead of using this pre-built image, one can also build their own virtual
  25746. machine image using @command{guix system vm-image} (@pxref{Invoking guix
  25747. system}). The returned image is in qcow2 format, which the
  25748. @uref{https://qemu.org/, QEMU emulator} can efficiently use.
  25749. @cindex QEMU
  25750. If you built your own image, you must copy it out of the store
  25751. (@pxref{The Store}) and give yourself permission to write to the copy
  25752. before you can use it. When invoking QEMU, you must choose a system
  25753. emulator that is suitable for your hardware platform. Here is a minimal
  25754. QEMU invocation that will boot the result of @command{guix system
  25755. vm-image} on x86_64 hardware:
  25756. @example
  25757. $ qemu-system-x86_64 \
  25758. -nic user,model=virtio-net-pci \
  25759. -enable-kvm -m 1024 \
  25760. -device virtio-blk,drive=myhd \
  25761. -drive if=none,file=/tmp/qemu-image,id=myhd
  25762. @end example
  25763. Here is what each of these options means:
  25764. @table @code
  25765. @item qemu-system-x86_64
  25766. This specifies the hardware platform to emulate. This should match the
  25767. host.
  25768. @item -nic user,model=virtio-net-pci
  25769. Enable the unprivileged user-mode network stack. The guest OS can
  25770. access the host but not vice versa. This is the simplest way to get the
  25771. guest OS online. @code{model} specifies which network device to emulate:
  25772. @code{virtio-net-pci} is a special device made for virtualized operating
  25773. systems and recommended for most uses. Assuming your hardware platform is
  25774. x86_64, you can get a list of available NIC models by running
  25775. @command{qemu-system-x86_64 -nic model=help}.
  25776. @item -enable-kvm
  25777. If your system has hardware virtualization extensions, enabling the
  25778. virtual machine support (KVM) of the Linux kernel will make things run
  25779. faster.
  25780. @c To run Xfce + 'guix pull', we need at least 1G of RAM.
  25781. @item -m 1024
  25782. RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
  25783. which may be insufficient for some operations.
  25784. @item -device virtio-blk,drive=myhd
  25785. Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
  25786. ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
  25787. better performance than if it were emulating a complete disk drive. See the
  25788. QEMU and KVM documentation for more info.
  25789. @item -drive if=none,file=/tmp/qemu-image,id=myhd
  25790. Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
  25791. store of the ``myhd'' drive.
  25792. @end table
  25793. The default @command{run-vm.sh} script that is returned by an invocation of
  25794. @command{guix system vm} does not add a @command{-nic user} flag by default.
  25795. To get network access from within the vm add the @code{(dhcp-client-service)}
  25796. to your system definition and start the VM using
  25797. @command{`guix system vm config.scm` -nic user}. An important caveat of using
  25798. @command{-nic user} for networking is that @command{ping} will not work, because
  25799. it uses the ICMP protocol. You'll have to use a different command to check for
  25800. network connectivity, for example @command{guix download}.
  25801. @subsection Connecting Through SSH
  25802. @cindex SSH
  25803. @cindex SSH server
  25804. To enable SSH inside a VM you need to add an SSH server like
  25805. @code{openssh-service-type} to your VM (@pxref{Networking Services,
  25806. @code{openssh-service-type}}). In addition you need to forward the SSH port,
  25807. 22 by default, to the host. You can do this with
  25808. @example
  25809. `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
  25810. @end example
  25811. To connect to the VM you can run
  25812. @example
  25813. ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
  25814. @end example
  25815. The @command{-p} tells @command{ssh} the port you want to connect to.
  25816. @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
  25817. every time you modify your @command{config.scm} file and the
  25818. @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
  25819. connection to an unknown host every time you connect.
  25820. @subsection Using @command{virt-viewer} with Spice
  25821. As an alternative to the default @command{qemu} graphical client you can
  25822. use the @command{remote-viewer} from the @command{virt-viewer} package. To
  25823. connect pass the @command{-spice port=5930,disable-ticketing} flag to
  25824. @command{qemu}. See previous section for further information on how to do this.
  25825. Spice also allows you to do some nice stuff like share your clipboard with your
  25826. VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
  25827. @example
  25828. -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
  25829. -chardev spicevmc,name=vdagent,id=vdagent
  25830. -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
  25831. name=com.redhat.spice.0
  25832. @end example
  25833. You'll also need to add the @code{(spice-vdagent-service)} to your
  25834. system definition (@pxref{Miscellaneous Services, Spice service}).
  25835. @node Defining Services
  25836. @section Defining Services
  25837. The previous sections show the available services and how one can combine
  25838. them in an @code{operating-system} declaration. But how do we define
  25839. them in the first place? And what is a service anyway?
  25840. @menu
  25841. * Service Composition:: The model for composing services.
  25842. * Service Types and Services:: Types and services.
  25843. * Service Reference:: API reference.
  25844. * Shepherd Services:: A particular type of service.
  25845. @end menu
  25846. @node Service Composition
  25847. @subsection Service Composition
  25848. @cindex services
  25849. @cindex daemons
  25850. Here we define a @dfn{service} as, broadly, something that extends the
  25851. functionality of the operating system. Often a service is a process---a
  25852. @dfn{daemon}---started when the system boots: a secure shell server, a
  25853. Web server, the Guix build daemon, etc. Sometimes a service is a daemon
  25854. whose execution can be triggered by another daemon---e.g., an FTP server
  25855. started by @command{inetd} or a D-Bus service activated by
  25856. @command{dbus-daemon}. Occasionally, a service does not map to a
  25857. daemon. For instance, the ``account'' service collects user accounts
  25858. and makes sure they exist when the system runs; the ``udev'' service
  25859. collects device management rules and makes them available to the eudev
  25860. daemon; the @file{/etc} service populates the @file{/etc} directory
  25861. of the system.
  25862. @cindex service extensions
  25863. Guix system services are connected by @dfn{extensions}. For instance, the
  25864. secure shell service @emph{extends} the Shepherd---the
  25865. initialization system, running as PID@tie{}1---by giving it the command
  25866. lines to start and stop the secure shell daemon (@pxref{Networking
  25867. Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
  25868. service by passing it its @file{.service} specification, and extends the
  25869. udev service by passing it device management rules (@pxref{Desktop
  25870. Services, @code{upower-service}}); the Guix daemon service extends the
  25871. Shepherd by passing it the command lines to start and stop the daemon,
  25872. and extends the account service by passing it a list of required build
  25873. user accounts (@pxref{Base Services}).
  25874. All in all, services and their ``extends'' relations form a directed
  25875. acyclic graph (DAG). If we represent services as boxes and extensions
  25876. as arrows, a typical system might provide something like this:
  25877. @image{images/service-graph,,5in,Typical service extension graph.}
  25878. @cindex system service
  25879. At the bottom, we see the @dfn{system service}, which produces the
  25880. directory containing everything to run and boot the system, as returned
  25881. by the @command{guix system build} command. @xref{Service Reference},
  25882. to learn about the other service types shown here.
  25883. @xref{system-extension-graph, the @command{guix system extension-graph}
  25884. command}, for information on how to generate this representation for a
  25885. particular operating system definition.
  25886. @cindex service types
  25887. Technically, developers can define @dfn{service types} to express these
  25888. relations. There can be any number of services of a given type on the
  25889. system---for instance, a system running two instances of the GNU secure
  25890. shell server (lsh) has two instances of @code{lsh-service-type}, with
  25891. different parameters.
  25892. The following section describes the programming interface for service
  25893. types and services.
  25894. @node Service Types and Services
  25895. @subsection Service Types and Services
  25896. A @dfn{service type} is a node in the DAG described above. Let us start
  25897. with a simple example, the service type for the Guix build daemon
  25898. (@pxref{Invoking guix-daemon}):
  25899. @lisp
  25900. (define guix-service-type
  25901. (service-type
  25902. (name 'guix)
  25903. (extensions
  25904. (list (service-extension shepherd-root-service-type guix-shepherd-service)
  25905. (service-extension account-service-type guix-accounts)
  25906. (service-extension activation-service-type guix-activation)))
  25907. (default-value (guix-configuration))))
  25908. @end lisp
  25909. @noindent
  25910. It defines three things:
  25911. @enumerate
  25912. @item
  25913. A name, whose sole purpose is to make inspection and debugging easier.
  25914. @item
  25915. A list of @dfn{service extensions}, where each extension designates the
  25916. target service type and a procedure that, given the parameters of the
  25917. service, returns a list of objects to extend the service of that type.
  25918. Every service type has at least one service extension. The only
  25919. exception is the @dfn{boot service type}, which is the ultimate service.
  25920. @item
  25921. Optionally, a default value for instances of this type.
  25922. @end enumerate
  25923. In this example, @code{guix-service-type} extends three services:
  25924. @table @code
  25925. @item shepherd-root-service-type
  25926. The @code{guix-shepherd-service} procedure defines how the Shepherd
  25927. service is extended. Namely, it returns a @code{<shepherd-service>}
  25928. object that defines how @command{guix-daemon} is started and stopped
  25929. (@pxref{Shepherd Services}).
  25930. @item account-service-type
  25931. This extension for this service is computed by @code{guix-accounts},
  25932. which returns a list of @code{user-group} and @code{user-account}
  25933. objects representing the build user accounts (@pxref{Invoking
  25934. guix-daemon}).
  25935. @item activation-service-type
  25936. Here @code{guix-activation} is a procedure that returns a gexp, which is
  25937. a code snippet to run at ``activation time''---e.g., when the service is
  25938. booted.
  25939. @end table
  25940. A service of this type is instantiated like this:
  25941. @lisp
  25942. (service guix-service-type
  25943. (guix-configuration
  25944. (build-accounts 5)
  25945. (extra-options '("--gc-keep-derivations"))))
  25946. @end lisp
  25947. The second argument to the @code{service} form is a value representing
  25948. the parameters of this specific service instance.
  25949. @xref{guix-configuration-type, @code{guix-configuration}}, for
  25950. information about the @code{guix-configuration} data type. When the
  25951. value is omitted, the default value specified by
  25952. @code{guix-service-type} is used:
  25953. @lisp
  25954. (service guix-service-type)
  25955. @end lisp
  25956. @code{guix-service-type} is quite simple because it extends other
  25957. services but is not extensible itself.
  25958. @c @subsubsubsection Extensible Service Types
  25959. The service type for an @emph{extensible} service looks like this:
  25960. @lisp
  25961. (define udev-service-type
  25962. (service-type (name 'udev)
  25963. (extensions
  25964. (list (service-extension shepherd-root-service-type
  25965. udev-shepherd-service)))
  25966. (compose concatenate) ;concatenate the list of rules
  25967. (extend (lambda (config rules)
  25968. (match config
  25969. (($ <udev-configuration> udev initial-rules)
  25970. (udev-configuration
  25971. (udev udev) ;the udev package to use
  25972. (rules (append initial-rules rules)))))))))
  25973. @end lisp
  25974. This is the service type for the
  25975. @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
  25976. management daemon}. Compared to the previous example, in addition to an
  25977. extension of @code{shepherd-root-service-type}, we see two new fields:
  25978. @table @code
  25979. @item compose
  25980. This is the procedure to @dfn{compose} the list of extensions to
  25981. services of this type.
  25982. Services can extend the udev service by passing it lists of rules; we
  25983. compose those extensions simply by concatenating them.
  25984. @item extend
  25985. This procedure defines how the value of the service is @dfn{extended} with
  25986. the composition of the extensions.
  25987. Udev extensions are composed into a list of rules, but the udev service
  25988. value is itself a @code{<udev-configuration>} record. So here, we
  25989. extend that record by appending the list of rules it contains to the
  25990. list of contributed rules.
  25991. @item description
  25992. This is a string giving an overview of the service type. The string can
  25993. contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
  25994. @command{guix system search} command searches these strings and displays
  25995. them (@pxref{Invoking guix system}).
  25996. @end table
  25997. There can be only one instance of an extensible service type such as
  25998. @code{udev-service-type}. If there were more, the
  25999. @code{service-extension} specifications would be ambiguous.
  26000. Still here? The next section provides a reference of the programming
  26001. interface for services.
  26002. @node Service Reference
  26003. @subsection Service Reference
  26004. We have seen an overview of service types (@pxref{Service Types and
  26005. Services}). This section provides a reference on how to manipulate
  26006. services and service types. This interface is provided by the
  26007. @code{(gnu services)} module.
  26008. @deffn {Scheme Procedure} service @var{type} [@var{value}]
  26009. Return a new service of @var{type}, a @code{<service-type>} object (see
  26010. below). @var{value} can be any object; it represents the parameters of
  26011. this particular service instance.
  26012. When @var{value} is omitted, the default value specified by @var{type}
  26013. is used; if @var{type} does not specify a default value, an error is
  26014. raised.
  26015. For instance, this:
  26016. @lisp
  26017. (service openssh-service-type)
  26018. @end lisp
  26019. @noindent
  26020. is equivalent to this:
  26021. @lisp
  26022. (service openssh-service-type
  26023. (openssh-configuration))
  26024. @end lisp
  26025. In both cases the result is an instance of @code{openssh-service-type}
  26026. with the default configuration.
  26027. @end deffn
  26028. @deffn {Scheme Procedure} service? @var{obj}
  26029. Return true if @var{obj} is a service.
  26030. @end deffn
  26031. @deffn {Scheme Procedure} service-kind @var{service}
  26032. Return the type of @var{service}---i.e., a @code{<service-type>} object.
  26033. @end deffn
  26034. @deffn {Scheme Procedure} service-value @var{service}
  26035. Return the value associated with @var{service}. It represents its
  26036. parameters.
  26037. @end deffn
  26038. Here is an example of how a service is created and manipulated:
  26039. @lisp
  26040. (define s
  26041. (service nginx-service-type
  26042. (nginx-configuration
  26043. (nginx nginx)
  26044. (log-directory log-directory)
  26045. (run-directory run-directory)
  26046. (file config-file))))
  26047. (service? s)
  26048. @result{} #t
  26049. (eq? (service-kind s) nginx-service-type)
  26050. @result{} #t
  26051. @end lisp
  26052. The @code{modify-services} form provides a handy way to change the
  26053. parameters of some of the services of a list such as
  26054. @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
  26055. evaluates to a list of services. Of course, you could always use
  26056. standard list combinators such as @code{map} and @code{fold} to do that
  26057. (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
  26058. @code{modify-services} simply provides a more concise form for this
  26059. common pattern.
  26060. @deffn {Scheme Syntax} modify-services @var{services} @
  26061. (@var{type} @var{variable} => @var{body}) @dots{}
  26062. Modify the services listed in @var{services} according to the given
  26063. clauses. Each clause has the form:
  26064. @example
  26065. (@var{type} @var{variable} => @var{body})
  26066. @end example
  26067. where @var{type} is a service type---e.g.,
  26068. @code{guix-service-type}---and @var{variable} is an identifier that is
  26069. bound within the @var{body} to the service parameters---e.g., a
  26070. @code{guix-configuration} instance---of the original service of that
  26071. @var{type}.
  26072. The @var{body} should evaluate to the new service parameters, which will
  26073. be used to configure the new service. This new service will replace the
  26074. original in the resulting list. Because a service's service parameters
  26075. are created using @code{define-record-type*}, you can write a succinct
  26076. @var{body} that evaluates to the new service parameters by using the
  26077. @code{inherit} feature that @code{define-record-type*} provides.
  26078. @xref{Using the Configuration System}, for example usage.
  26079. @end deffn
  26080. Next comes the programming interface for service types. This is
  26081. something you want to know when writing new service definitions, but not
  26082. necessarily when simply looking for ways to customize your
  26083. @code{operating-system} declaration.
  26084. @deftp {Data Type} service-type
  26085. @cindex service type
  26086. This is the representation of a @dfn{service type} (@pxref{Service Types
  26087. and Services}).
  26088. @table @asis
  26089. @item @code{name}
  26090. This is a symbol, used only to simplify inspection and debugging.
  26091. @item @code{extensions}
  26092. A non-empty list of @code{<service-extension>} objects (see below).
  26093. @item @code{compose} (default: @code{#f})
  26094. If this is @code{#f}, then the service type denotes services that cannot
  26095. be extended---i.e., services that do not receive ``values'' from other
  26096. services.
  26097. Otherwise, it must be a one-argument procedure. The procedure is called
  26098. by @code{fold-services} and is passed a list of values collected from
  26099. extensions. It may return any single value.
  26100. @item @code{extend} (default: @code{#f})
  26101. If this is @code{#f}, services of this type cannot be extended.
  26102. Otherwise, it must be a two-argument procedure: @code{fold-services}
  26103. calls it, passing it the initial value of the service as the first
  26104. argument and the result of applying @code{compose} to the extension
  26105. values as the second argument. It must return a value that is a valid
  26106. parameter value for the service instance.
  26107. @item @code{description}
  26108. This is a string, possibly using Texinfo markup, describing in a couple
  26109. of sentences what the service is about. This string allows users to
  26110. find about the service through @command{guix system search}
  26111. (@pxref{Invoking guix system}).
  26112. @item @code{default-value} (default: @code{&no-default-value})
  26113. The default value associated for instances of this service type. This
  26114. allows users to use the @code{service} form without its second argument:
  26115. @lisp
  26116. (service @var{type})
  26117. @end lisp
  26118. The returned service in this case has the default value specified by
  26119. @var{type}.
  26120. @end table
  26121. @xref{Service Types and Services}, for examples.
  26122. @end deftp
  26123. @deffn {Scheme Procedure} service-extension @var{target-type} @
  26124. @var{compute}
  26125. Return a new extension for services of type @var{target-type}.
  26126. @var{compute} must be a one-argument procedure: @code{fold-services}
  26127. calls it, passing it the value associated with the service that provides
  26128. the extension; it must return a valid value for the target service.
  26129. @end deffn
  26130. @deffn {Scheme Procedure} service-extension? @var{obj}
  26131. Return true if @var{obj} is a service extension.
  26132. @end deffn
  26133. Occasionally, you might want to simply extend an existing service. This
  26134. involves creating a new service type and specifying the extension of
  26135. interest, which can be verbose; the @code{simple-service} procedure
  26136. provides a shorthand for this.
  26137. @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
  26138. Return a service that extends @var{target} with @var{value}. This works
  26139. by creating a singleton service type @var{name}, of which the returned
  26140. service is an instance.
  26141. For example, this extends mcron (@pxref{Scheduled Job Execution}) with
  26142. an additional job:
  26143. @lisp
  26144. (simple-service 'my-mcron-job mcron-service-type
  26145. #~(job '(next-hour (3)) "guix gc -F 2G"))
  26146. @end lisp
  26147. @end deffn
  26148. At the core of the service abstraction lies the @code{fold-services}
  26149. procedure, which is responsible for ``compiling'' a list of services
  26150. down to a single directory that contains everything needed to boot and
  26151. run the system---the directory shown by the @command{guix system build}
  26152. command (@pxref{Invoking guix system}). In essence, it propagates
  26153. service extensions down the service graph, updating each node parameters
  26154. on the way, until it reaches the root node.
  26155. @deffn {Scheme Procedure} fold-services @var{services} @
  26156. [#:target-type @var{system-service-type}]
  26157. Fold @var{services} by propagating their extensions down to the root of
  26158. type @var{target-type}; return the root service adjusted accordingly.
  26159. @end deffn
  26160. Lastly, the @code{(gnu services)} module also defines several essential
  26161. service types, some of which are listed below.
  26162. @defvr {Scheme Variable} system-service-type
  26163. This is the root of the service graph. It produces the system directory
  26164. as returned by the @command{guix system build} command.
  26165. @end defvr
  26166. @defvr {Scheme Variable} boot-service-type
  26167. The type of the ``boot service'', which produces the @dfn{boot script}.
  26168. The boot script is what the initial RAM disk runs when booting.
  26169. @end defvr
  26170. @defvr {Scheme Variable} etc-service-type
  26171. The type of the @file{/etc} service. This service is used to create
  26172. files under @file{/etc} and can be extended by
  26173. passing it name/file tuples such as:
  26174. @lisp
  26175. (list `("issue" ,(plain-file "issue" "Welcome!\n")))
  26176. @end lisp
  26177. In this example, the effect would be to add an @file{/etc/issue} file
  26178. pointing to the given file.
  26179. @end defvr
  26180. @defvr {Scheme Variable} setuid-program-service-type
  26181. Type for the ``setuid-program service''. This service collects lists of
  26182. executable file names, passed as gexps, and adds them to the set of
  26183. setuid-root programs on the system (@pxref{Setuid Programs}).
  26184. @end defvr
  26185. @defvr {Scheme Variable} profile-service-type
  26186. Type of the service that populates the @dfn{system profile}---i.e., the
  26187. programs under @file{/run/current-system/profile}. Other services can
  26188. extend it by passing it lists of packages to add to the system profile.
  26189. @end defvr
  26190. @cindex provenance tracking, of the operating system
  26191. @anchor{provenance-service-type}
  26192. @defvr {Scheme Variable} provenance-service-type
  26193. This is the type of the service that records @dfn{provenance meta-data}
  26194. in the system itself. It creates several files under
  26195. @file{/run/current-system}:
  26196. @table @file
  26197. @item channels.scm
  26198. This is a ``channel file'' that can be passed to @command{guix pull -C}
  26199. or @command{guix time-machine -C}, and which describes the channels used
  26200. to build the system, if that information was available
  26201. (@pxref{Channels}).
  26202. @item configuration.scm
  26203. This is the file that was passed as the value for this
  26204. @code{provenance-service-type} service. By default, @command{guix
  26205. system reconfigure} automatically passes the OS configuration file it
  26206. received on the command line.
  26207. @item provenance
  26208. This contains the same information as the two other files but in a
  26209. format that is more readily processable.
  26210. @end table
  26211. In general, these two pieces of information (channels and configuration
  26212. file) are enough to reproduce the operating system ``from source''.
  26213. @quotation Caveats
  26214. This information is necessary to rebuild your operating system, but it
  26215. is not always sufficient. In particular, @file{configuration.scm}
  26216. itself is insufficient if it is not self-contained---if it refers to
  26217. external Guile modules or to extra files. If you want
  26218. @file{configuration.scm} to be self-contained, we recommend that modules
  26219. or files it refers to be part of a channel.
  26220. Besides, provenance meta-data is ``silent'' in the sense that it does
  26221. not change the bits contained in your system, @emph{except for the
  26222. meta-data bits themselves}. Two different OS configurations or sets of
  26223. channels can lead to the same system, bit-for-bit; when
  26224. @code{provenance-service-type} is used, these two systems will have
  26225. different meta-data and thus different store file names, which makes
  26226. comparison less trivial.
  26227. @end quotation
  26228. This service is automatically added to your operating system
  26229. configuration when you use @command{guix system reconfigure},
  26230. @command{guix system init}, or @command{guix deploy}.
  26231. @end defvr
  26232. @node Shepherd Services
  26233. @subsection Shepherd Services
  26234. @cindex shepherd services
  26235. @cindex PID 1
  26236. @cindex init system
  26237. The @code{(gnu services shepherd)} module provides a way to define
  26238. services managed by the GNU@tie{}Shepherd, which is the
  26239. initialization system---the first process that is started when the
  26240. system boots, also known as PID@tie{}1
  26241. (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
  26242. Services in the Shepherd can depend on each other. For instance, the
  26243. SSH daemon may need to be started after the syslog daemon has been
  26244. started, which in turn can only happen once all the file systems have
  26245. been mounted. The simple operating system defined earlier (@pxref{Using
  26246. the Configuration System}) results in a service graph like this:
  26247. @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
  26248. You can actually generate such a graph for any operating system
  26249. definition using the @command{guix system shepherd-graph} command
  26250. (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
  26251. The @code{%shepherd-root-service} is a service object representing
  26252. PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
  26253. by passing it lists of @code{<shepherd-service>} objects.
  26254. @deftp {Data Type} shepherd-service
  26255. The data type representing a service managed by the Shepherd.
  26256. @table @asis
  26257. @item @code{provision}
  26258. This is a list of symbols denoting what the service provides.
  26259. These are the names that may be passed to @command{herd start},
  26260. @command{herd status}, and similar commands (@pxref{Invoking herd,,,
  26261. shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
  26262. @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
  26263. @item @code{requirement} (default: @code{'()})
  26264. List of symbols denoting the Shepherd services this one depends on.
  26265. @cindex one-shot services, for the Shepherd
  26266. @item @code{one-shot?} (default: @code{#f})
  26267. Whether this service is @dfn{one-shot}. One-shot services stop immediately
  26268. after their @code{start} action has completed. @xref{Slots of services,,,
  26269. shepherd, The GNU Shepherd Manual}, for more info.
  26270. @item @code{respawn?} (default: @code{#t})
  26271. Whether to restart the service when it stops, for instance when the
  26272. underlying process dies.
  26273. @item @code{start}
  26274. @itemx @code{stop} (default: @code{#~(const #f)})
  26275. The @code{start} and @code{stop} fields refer to the Shepherd's
  26276. facilities to start and stop processes (@pxref{Service De- and
  26277. Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
  26278. G-expressions that get expanded in the Shepherd configuration file
  26279. (@pxref{G-Expressions}).
  26280. @item @code{actions} (default: @code{'()})
  26281. @cindex actions, of Shepherd services
  26282. This is a list of @code{shepherd-action} objects (see below) defining
  26283. @dfn{actions} supported by the service, in addition to the standard
  26284. @code{start} and @code{stop} actions. Actions listed here become available as
  26285. @command{herd} sub-commands:
  26286. @example
  26287. herd @var{action} @var{service} [@var{arguments}@dots{}]
  26288. @end example
  26289. @item @code{auto-start?} (default: @code{#t})
  26290. Whether this service should be started automatically by the Shepherd. If it
  26291. is @code{#f} the service has to be started manually with @code{herd start}.
  26292. @item @code{documentation}
  26293. A documentation string, as shown when running:
  26294. @example
  26295. herd doc @var{service-name}
  26296. @end example
  26297. where @var{service-name} is one of the symbols in @code{provision}
  26298. (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
  26299. @item @code{modules} (default: @code{%default-modules})
  26300. This is the list of modules that must be in scope when @code{start} and
  26301. @code{stop} are evaluated.
  26302. @end table
  26303. @end deftp
  26304. @deftp {Data Type} shepherd-action
  26305. This is the data type that defines additional actions implemented by a
  26306. Shepherd service (see above).
  26307. @table @code
  26308. @item name
  26309. Symbol naming the action.
  26310. @item documentation
  26311. This is a documentation string for the action. It can be viewed by running:
  26312. @example
  26313. herd doc @var{service} action @var{action}
  26314. @end example
  26315. @item procedure
  26316. This should be a gexp that evaluates to a procedure of at least one argument,
  26317. which is the ``running value'' of the service (@pxref{Slots of services,,,
  26318. shepherd, The GNU Shepherd Manual}).
  26319. @end table
  26320. The following example defines an action called @code{say-hello} that kindly
  26321. greets the user:
  26322. @lisp
  26323. (shepherd-action
  26324. (name 'say-hello)
  26325. (documentation "Say hi!")
  26326. (procedure #~(lambda (running . args)
  26327. (format #t "Hello, friend! arguments: ~s\n"
  26328. args)
  26329. #t)))
  26330. @end lisp
  26331. Assuming this action is added to the @code{example} service, then you can do:
  26332. @example
  26333. # herd say-hello example
  26334. Hello, friend! arguments: ()
  26335. # herd say-hello example a b c
  26336. Hello, friend! arguments: ("a" "b" "c")
  26337. @end example
  26338. This, as you can see, is a fairly sophisticated way to say hello.
  26339. @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
  26340. info on actions.
  26341. @end deftp
  26342. @defvr {Scheme Variable} shepherd-root-service-type
  26343. The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
  26344. This is the service type that extensions target when they want to create
  26345. shepherd services (@pxref{Service Types and Services}, for an example).
  26346. Each extension must pass a list of @code{<shepherd-service>}. Its
  26347. value must be a @code{shepherd-configuration}, as described below.
  26348. @end defvr
  26349. @deftp {Data Type} shepherd-configuration
  26350. This data type represents the Shepherd's configuration.
  26351. @table @code
  26352. @item shepherd (default: @code{shepherd})
  26353. The Shepherd package to use.
  26354. @item services (default: @code{'()})
  26355. A list of @code{<shepherd-service>} to start.
  26356. You should probably use the service extension
  26357. mechanism instead (@pxref{Shepherd Services}).
  26358. @end table
  26359. @end deftp
  26360. The following example specifies the Shepherd package for the operating
  26361. system:
  26362. @lisp
  26363. (operating-system
  26364. ;; ...
  26365. (services (append (list openssh-service-type))
  26366. ;; ...
  26367. %desktop-services)
  26368. ;; ...
  26369. ;; Use own Shepherd package.
  26370. (essential-services
  26371. (modify-services (operating-system-default-essential-services
  26372. this-operating-system)
  26373. (shepherd-root-service-type config => (shepherd-configuration
  26374. (inherit config)
  26375. (shepherd my-shepherd))))))
  26376. @end lisp
  26377. @defvr {Scheme Variable} %shepherd-root-service
  26378. This service represents PID@tie{}1.
  26379. @end defvr
  26380. @node Documentation
  26381. @chapter Documentation
  26382. @cindex documentation, searching for
  26383. @cindex searching for documentation
  26384. @cindex Info, documentation format
  26385. @cindex man pages
  26386. @cindex manual pages
  26387. In most cases packages installed with Guix come with documentation.
  26388. There are two main documentation formats: ``Info'', a browseable
  26389. hypertext format used for GNU software, and ``manual pages'' (or ``man
  26390. pages''), the linear documentation format traditionally found on Unix.
  26391. Info manuals are accessed with the @command{info} command or with Emacs,
  26392. and man pages are accessed using @command{man}.
  26393. You can look for documentation of software installed on your system by
  26394. keyword. For example, the following command searches for information
  26395. about ``TLS'' in Info manuals:
  26396. @example
  26397. $ info -k TLS
  26398. "(emacs)Network Security" -- STARTTLS
  26399. "(emacs)Network Security" -- TLS
  26400. "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
  26401. "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
  26402. @dots{}
  26403. @end example
  26404. @noindent
  26405. The command below searches for the same keyword in man pages:
  26406. @example
  26407. $ man -k TLS
  26408. SSL (7) - OpenSSL SSL/TLS library
  26409. certtool (1) - GnuTLS certificate tool
  26410. @dots {}
  26411. @end example
  26412. These searches are purely local to your computer so you have the
  26413. guarantee that documentation you find corresponds to what you have
  26414. actually installed, you can access it off-line, and your privacy is
  26415. respected.
  26416. Once you have these results, you can view the relevant documentation by
  26417. running, say:
  26418. @example
  26419. $ info "(gnutls)Core TLS API"
  26420. @end example
  26421. @noindent
  26422. or:
  26423. @example
  26424. $ man certtool
  26425. @end example
  26426. Info manuals contain sections and indices as well as hyperlinks like
  26427. those found in Web pages. The @command{info} reader (@pxref{Top, Info
  26428. reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
  26429. (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
  26430. bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
  26431. Introduction}, for an introduction to Info navigation.
  26432. @node Installing Debugging Files
  26433. @chapter Installing Debugging Files
  26434. @cindex debugging files
  26435. Program binaries, as produced by the GCC compilers for instance, are
  26436. typically written in the ELF format, with a section containing
  26437. @dfn{debugging information}. Debugging information is what allows the
  26438. debugger, GDB, to map binary code to source code; it is required to
  26439. debug a compiled program in good conditions.
  26440. This chapter explains how to use separate debug info when packages
  26441. provide it, and how to rebuild packages with debug info when it's
  26442. missing.
  26443. @menu
  26444. * Separate Debug Info:: Installing 'debug' outputs.
  26445. * Rebuilding Debug Info:: Building missing debug info.
  26446. @end menu
  26447. @node Separate Debug Info
  26448. @section Separate Debug Info
  26449. The problem with debugging information is that is takes up a fair amount
  26450. of disk space. For example, debugging information for the GNU C Library
  26451. weighs in at more than 60 MiB@. Thus, as a user, keeping all the
  26452. debugging info of all the installed programs is usually not an option.
  26453. Yet, space savings should not come at the cost of an impediment to
  26454. debugging---especially in the GNU system, which should make it easier
  26455. for users to exert their computing freedom (@pxref{GNU Distribution}).
  26456. Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
  26457. mechanism that allows users to get the best of both worlds: debugging
  26458. information can be stripped from the binaries and stored in separate
  26459. files. GDB is then able to load debugging information from those files,
  26460. when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
  26461. with GDB}).
  26462. The GNU distribution takes advantage of this by storing debugging
  26463. information in the @code{lib/debug} sub-directory of a separate package
  26464. output unimaginatively called @code{debug} (@pxref{Packages with
  26465. Multiple Outputs}). Users can choose to install the @code{debug} output
  26466. of a package when they need it. For instance, the following command
  26467. installs the debugging information for the GNU C Library and for GNU
  26468. Guile:
  26469. @example
  26470. guix install glibc:debug guile:debug
  26471. @end example
  26472. GDB must then be told to look for debug files in the user's profile, by
  26473. setting the @code{debug-file-directory} variable (consider setting it
  26474. from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
  26475. GDB}):
  26476. @example
  26477. (gdb) set debug-file-directory ~/.guix-profile/lib/debug
  26478. @end example
  26479. From there on, GDB will pick up debugging information from the
  26480. @file{.debug} files under @file{~/.guix-profile/lib/debug}.
  26481. In addition, you will most likely want GDB to be able to show the source
  26482. code being debugged. To do that, you will have to unpack the source
  26483. code of the package of interest (obtained with @code{guix build
  26484. --source}, @pxref{Invoking guix build}), and to point GDB to that source
  26485. directory using the @code{directory} command (@pxref{Source Path,
  26486. @code{directory},, gdb, Debugging with GDB}).
  26487. @c XXX: keep me up-to-date
  26488. The @code{debug} output mechanism in Guix is implemented by the
  26489. @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
  26490. opt-in---debugging information is available only for the packages with
  26491. definitions explicitly declaring a @code{debug} output. To check
  26492. whether a package has a @code{debug} output, use @command{guix package
  26493. --list-available} (@pxref{Invoking guix package}).
  26494. Read on for how to deal with packages lacking a @code{debug} output.
  26495. @node Rebuilding Debug Info
  26496. @section Rebuilding Debug Info
  26497. @cindex debugging info, rebuilding
  26498. As we saw above, some packages, but not all, provide debugging info in a
  26499. @code{debug} output. What can you do when debugging info is missing?
  26500. The @option{--with-debug-info} option provides a solution to that: it
  26501. allows you to rebuild the package(s) for which debugging info is
  26502. missing---and only those---and to graft those onto the application
  26503. you're debugging. Thus, while it's not as fast as installing a
  26504. @code{debug} output, it is relatively inexpensive.
  26505. Let's illustrate that. Suppose you're experiencing a bug in Inkscape
  26506. and would like to see what's going on in GLib, a library that's deep
  26507. down in its dependency graph. As it turns out, GLib does not have a
  26508. @code{debug} output and the backtrace GDB shows is all sadness:
  26509. @example
  26510. (gdb) bt
  26511. #0 0x00007ffff5f92190 in g_getenv ()
  26512. from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
  26513. #1 0x00007ffff608a7d6 in gobject_init_ctor ()
  26514. from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
  26515. #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
  26516. env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
  26517. #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
  26518. at dl-init.c:118
  26519. @end example
  26520. To address that, you install Inkscape linked against a variant GLib that
  26521. contains debug info:
  26522. @example
  26523. guix install inkscape --with-debug-info=glib
  26524. @end example
  26525. This time, debugging will be a whole lot nicer:
  26526. @example
  26527. $ gdb --args sh -c 'exec inkscape'
  26528. @dots{}
  26529. (gdb) b g_getenv
  26530. Function "g_getenv" not defined.
  26531. Make breakpoint pending on future shared library load? (y or [n]) y
  26532. Breakpoint 1 (g_getenv) pending.
  26533. (gdb) r
  26534. Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
  26535. @dots{}
  26536. (gdb) bt
  26537. #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
  26538. #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
  26539. #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
  26540. #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
  26541. env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
  26542. @dots{}
  26543. @end example
  26544. Much better!
  26545. Note that there can be packages for which @option{--with-debug-info}
  26546. will not have the desired effect. @xref{Package Transformation Options,
  26547. @option{--with-debug-info}}, for more information.
  26548. @node Security Updates
  26549. @chapter Security Updates
  26550. @cindex security updates
  26551. @cindex security vulnerabilities
  26552. Occasionally, important security vulnerabilities are discovered in software
  26553. packages and must be patched. Guix developers try hard to keep track of
  26554. known vulnerabilities and to apply fixes as soon as possible in the
  26555. @code{master} branch of Guix (we do not yet provide a ``stable'' branch
  26556. containing only security updates). The @command{guix lint} tool helps
  26557. developers find out about vulnerable versions of software packages in the
  26558. distribution:
  26559. @smallexample
  26560. $ guix lint -c cve
  26561. gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
  26562. gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
  26563. gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
  26564. @dots{}
  26565. @end smallexample
  26566. @xref{Invoking guix lint}, for more information.
  26567. Guix follows a functional
  26568. package management discipline (@pxref{Introduction}), which implies
  26569. that, when a package is changed, @emph{every package that depends on it}
  26570. must be rebuilt. This can significantly slow down the deployment of
  26571. fixes in core packages such as libc or Bash, since basically the whole
  26572. distribution would need to be rebuilt. Using pre-built binaries helps
  26573. (@pxref{Substitutes}), but deployment may still take more time than
  26574. desired.
  26575. @cindex grafts
  26576. To address this, Guix implements @dfn{grafts}, a mechanism that allows
  26577. for fast deployment of critical updates without the costs associated
  26578. with a whole-distribution rebuild. The idea is to rebuild only the
  26579. package that needs to be patched, and then to ``graft'' it onto packages
  26580. explicitly installed by the user and that were previously referring to
  26581. the original package. The cost of grafting is typically very low, and
  26582. order of magnitudes lower than a full rebuild of the dependency chain.
  26583. @cindex replacements of packages, for grafts
  26584. For instance, suppose a security update needs to be applied to Bash.
  26585. Guix developers will provide a package definition for the ``fixed''
  26586. Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
  26587. Packages}). Then, the original package definition is augmented with a
  26588. @code{replacement} field pointing to the package containing the bug fix:
  26589. @lisp
  26590. (define bash
  26591. (package
  26592. (name "bash")
  26593. ;; @dots{}
  26594. (replacement bash-fixed)))
  26595. @end lisp
  26596. From there on, any package depending directly or indirectly on Bash---as
  26597. reported by @command{guix gc --requisites} (@pxref{Invoking guix
  26598. gc})---that is installed is automatically ``rewritten'' to refer to
  26599. @code{bash-fixed} instead of @code{bash}. This grafting process takes
  26600. time proportional to the size of the package, usually less than a
  26601. minute for an ``average'' package on a recent machine. Grafting is
  26602. recursive: when an indirect dependency requires grafting, then grafting
  26603. ``propagates'' up to the package that the user is installing.
  26604. Currently, the length of the name and version of the graft and that of
  26605. the package it replaces (@code{bash-fixed} and @code{bash} in the example
  26606. above) must be equal. This restriction mostly comes from the fact that
  26607. grafting works by patching files, including binary files, directly.
  26608. Other restrictions may apply: for instance, when adding a graft to a
  26609. package providing a shared library, the original shared library and its
  26610. replacement must have the same @code{SONAME} and be binary-compatible.
  26611. The @option{--no-grafts} command-line option allows you to forcefully
  26612. avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
  26613. Thus, the command:
  26614. @example
  26615. guix build bash --no-grafts
  26616. @end example
  26617. @noindent
  26618. returns the store file name of the original Bash, whereas:
  26619. @example
  26620. guix build bash
  26621. @end example
  26622. @noindent
  26623. returns the store file name of the ``fixed'', replacement Bash. This
  26624. allows you to distinguish between the two variants of Bash.
  26625. To verify which Bash your whole profile refers to, you can run
  26626. (@pxref{Invoking guix gc}):
  26627. @example
  26628. guix gc -R `readlink -f ~/.guix-profile` | grep bash
  26629. @end example
  26630. @noindent
  26631. @dots{} and compare the store file names that you get with those above.
  26632. Likewise for a complete Guix system generation:
  26633. @example
  26634. guix gc -R `guix system build my-config.scm` | grep bash
  26635. @end example
  26636. Lastly, to check which Bash running processes are using, you can use the
  26637. @command{lsof} command:
  26638. @example
  26639. lsof | grep /gnu/store/.*bash
  26640. @end example
  26641. @node Bootstrapping
  26642. @chapter Bootstrapping
  26643. @c Adapted from the ELS 2013 paper.
  26644. @cindex bootstrapping
  26645. Bootstrapping in our context refers to how the distribution gets built
  26646. ``from nothing''. Remember that the build environment of a derivation
  26647. contains nothing but its declared inputs (@pxref{Introduction}). So
  26648. there's an obvious chicken-and-egg problem: how does the first package
  26649. get built? How does the first compiler get compiled?
  26650. It is tempting to think of this question as one that only die-hard
  26651. hackers may care about. However, while the answer to that question is
  26652. technical in nature, its implications are wide-ranging. How the
  26653. distribution is bootstrapped defines the extent to which we, as
  26654. individuals and as a collective of users and hackers, can trust the
  26655. software we run. It is a central concern from the standpoint of
  26656. @emph{security} and from a @emph{user freedom} viewpoint.
  26657. @cindex bootstrap binaries
  26658. The GNU system is primarily made of C code, with libc at its core. The
  26659. GNU build system itself assumes the availability of a Bourne shell and
  26660. command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
  26661. `grep'. Furthermore, build programs---programs that run
  26662. @code{./configure}, @code{make}, etc.---are written in Guile Scheme
  26663. (@pxref{Derivations}). Consequently, to be able to build anything at
  26664. all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
  26665. Binutils, libc, and the other packages mentioned above---the
  26666. @dfn{bootstrap binaries}.
  26667. These bootstrap binaries are ``taken for granted'', though we can also
  26668. re-create them if needed (@pxref{Preparing to Use the Bootstrap
  26669. Binaries}).
  26670. @menu
  26671. * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
  26672. * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
  26673. @end menu
  26674. @node Reduced Binary Seed Bootstrap
  26675. @section The Reduced Binary Seed Bootstrap
  26676. Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
  26677. a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
  26678. Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
  26679. GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
  26680. ``taken for granted.''
  26681. Taking the bootstrap binaries for granted means that we consider them to
  26682. be a correct and trustworthy ``seed'' for building the complete system.
  26683. Therein lies a problem: the combined size of these bootstrap binaries is
  26684. about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
  26685. or even inspecting these is next to impossible.
  26686. For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
  26687. ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
  26688. Source Bootstrap'' and while we are working towards that goal it would
  26689. be hyperbole to use that term for what we do now.}.
  26690. The Reduced Binary Seed bootstrap removes the most critical tools---from a
  26691. trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
  26692. Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
  26693. linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
  26694. written in Scheme and the Mes C Library, built for TinyCC and for GCC).
  26695. Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
  26696. C Library are built from source. From here on the more traditional
  26697. bootstrap process resumes. This approach has reduced the bootstrap
  26698. binaries in size to about 145MB in Guix v1.1.
  26699. The next step that Guix has taken is to replace the shell and all its
  26700. utilities with implementations in Guile Scheme, the @emph{Scheme-only
  26701. bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
  26702. POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
  26703. which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
  26704. Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
  26705. removed are now built from source.
  26706. Building the GNU System from source is currently only possibly by adding
  26707. some historical GNU packages as intermediate steps@footnote{Packages
  26708. such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
  26709. @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
  26710. @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
  26711. and GNU packages become more bootstrappable again (e.g., new releases of
  26712. GNU Sed will also ship as gzipped tarballs again, as alternative to the
  26713. hard to bootstrap @code{xz}-compression), this set of added packages can
  26714. hopefully be reduced again.
  26715. The graph below shows the resulting dependency graph for
  26716. @code{gcc-core-mesboot0}, the bootstrap compiler used for the
  26717. traditional bootstrap of the rest of the Guix System.
  26718. @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
  26719. @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
  26720. The only significant binary bootstrap seeds that remain@footnote{
  26721. Ignoring the 68KB @code{mescc-tools}; that will be removed later,
  26722. together with @code{mes}.} are a Scheme intepreter and a Scheme
  26723. compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
  26724. static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
  26725. to get Guile running.}.
  26726. This further reduction has brought down the size of the binary seed to
  26727. about 60MB for @code{i686-linux} and @code{x86_64-linux}.
  26728. Work is ongoing to remove all binary blobs from our free software
  26729. bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
  26730. is work to bring these bootstraps to the @code{arm-linux} and
  26731. @code{aarch64-linux} architectures and to the Hurd.
  26732. If you are interested, join us on @samp{#bootstrappable} on the Freenode
  26733. IRC network or discuss on @email{bug-mes@@gnu.org} or
  26734. @email{gash-devel@@nongnu.org}.
  26735. @node Preparing to Use the Bootstrap Binaries
  26736. @section Preparing to Use the Bootstrap Binaries
  26737. @c As of Emacs 24.3, Info-mode displays the image, but since it's a
  26738. @c large image, it's hard to scroll. Oh well.
  26739. @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
  26740. The figure above shows the very beginning of the dependency graph of the
  26741. distribution, corresponding to the package definitions of the @code{(gnu
  26742. packages bootstrap)} module. A similar figure can be generated with
  26743. @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
  26744. @example
  26745. guix graph -t derivation \
  26746. -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
  26747. | dot -Tps > gcc.ps
  26748. @end example
  26749. or, for the further Reduced Binary Seed bootstrap
  26750. @example
  26751. guix graph -t derivation \
  26752. -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
  26753. | dot -Tps > mes.ps
  26754. @end example
  26755. At this level of detail, things are
  26756. slightly complex. First, Guile itself consists of an ELF executable,
  26757. along with many source and compiled Scheme files that are dynamically
  26758. loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
  26759. tarball shown in this graph. This tarball is part of Guix's ``source''
  26760. distribution, and gets inserted into the store with @code{add-to-store}
  26761. (@pxref{The Store}).
  26762. But how do we write a derivation that unpacks this tarball and adds it
  26763. to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
  26764. derivation---the first one that gets built---uses @code{bash} as its
  26765. builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
  26766. @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
  26767. @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
  26768. the Guix source distribution, whose sole purpose is to allow the Guile
  26769. tarball to be unpacked.
  26770. Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
  26771. Guile that can be used to run subsequent build programs. Its first task
  26772. is to download tarballs containing the other pre-built binaries---this
  26773. is what the @file{.tar.xz.drv} derivations do. Guix modules such as
  26774. @code{ftp-client.scm} are used for this purpose. The
  26775. @code{module-import.drv} derivations import those modules in a directory
  26776. in the store, using the original layout. The
  26777. @code{module-import-compiled.drv} derivations compile those modules, and
  26778. write them in an output directory with the right layout. This
  26779. corresponds to the @code{#:modules} argument of
  26780. @code{build-expression->derivation} (@pxref{Derivations}).
  26781. Finally, the various tarballs are unpacked by the derivations
  26782. @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
  26783. @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
  26784. point we have a working C tool chain.
  26785. @unnumberedsec Building the Build Tools
  26786. Bootstrapping is complete when we have a full tool chain that does not
  26787. depend on the pre-built bootstrap tools discussed above. This
  26788. no-dependency requirement is verified by checking whether the files of
  26789. the final tool chain contain references to the @file{/gnu/store}
  26790. directories of the bootstrap inputs. The process that leads to this
  26791. ``final'' tool chain is described by the package definitions found in
  26792. the @code{(gnu packages commencement)} module.
  26793. The @command{guix graph} command allows us to ``zoom out'' compared to
  26794. the graph above, by looking at the level of package objects instead of
  26795. individual derivations---remember that a package may translate to
  26796. several derivations, typically one derivation to download its source,
  26797. one to build the Guile modules it needs, and one to actually build the
  26798. package from source. The command:
  26799. @example
  26800. guix graph -t bag \
  26801. -e '(@@@@ (gnu packages commencement)
  26802. glibc-final-with-bootstrap-bash)' | xdot -
  26803. @end example
  26804. @noindent
  26805. displays the dependency graph leading to the ``final'' C
  26806. library@footnote{You may notice the @code{glibc-intermediate} label,
  26807. suggesting that it is not @emph{quite} final, but as a good
  26808. approximation, we will consider it final.}, depicted below.
  26809. @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
  26810. @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
  26811. The first tool that gets built with the bootstrap binaries is
  26812. GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
  26813. for all the following packages. From there Findutils and Diffutils get
  26814. built.
  26815. Then come the first-stage Binutils and GCC, built as pseudo cross
  26816. tools---i.e., with @option{--target} equal to @option{--host}. They are
  26817. used to build libc. Thanks to this cross-build trick, this libc is
  26818. guaranteed not to hold any reference to the initial tool chain.
  26819. From there the final Binutils and GCC (not shown above) are built. GCC
  26820. uses @command{ld} from the final Binutils, and links programs against
  26821. the just-built libc. This tool chain is used to build the other
  26822. packages used by Guix and by the GNU Build System: Guile, Bash,
  26823. Coreutils, etc.
  26824. And voilà! At this point we have the complete set of build tools that
  26825. the GNU Build System expects. These are in the @code{%final-inputs}
  26826. variable of the @code{(gnu packages commencement)} module, and are
  26827. implicitly used by any package that uses @code{gnu-build-system}
  26828. (@pxref{Build Systems, @code{gnu-build-system}}).
  26829. @unnumberedsec Building the Bootstrap Binaries
  26830. @cindex bootstrap binaries
  26831. Because the final tool chain does not depend on the bootstrap binaries,
  26832. those rarely need to be updated. Nevertheless, it is useful to have an
  26833. automated way to produce them, should an update occur, and this is what
  26834. the @code{(gnu packages make-bootstrap)} module provides.
  26835. The following command builds the tarballs containing the bootstrap binaries
  26836. (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
  26837. bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
  26838. and Guile, and a tarball containing a mixture of Coreutils and other basic
  26839. command-line tools):
  26840. @example
  26841. guix build bootstrap-tarballs
  26842. @end example
  26843. The generated tarballs are those that should be referred to in the
  26844. @code{(gnu packages bootstrap)} module mentioned at the beginning of
  26845. this section.
  26846. Still here? Then perhaps by now you've started to wonder: when do we
  26847. reach a fixed point? That is an interesting question! The answer is
  26848. unknown, but if you would like to investigate further (and have
  26849. significant computational and storage resources to do so), then let us
  26850. know.
  26851. @unnumberedsec Reducing the Set of Bootstrap Binaries
  26852. Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
  26853. binary code! Why is that a problem? It's a problem because these big chunks
  26854. of binary code are practically non-auditable, which makes it hard to establish
  26855. what source code produced them. Every unauditable binary also leaves us
  26856. vulnerable to compiler backdoors as described by Ken Thompson in the 1984
  26857. paper @emph{Reflections on Trusting Trust}.
  26858. This is mitigated by the fact that our bootstrap binaries were generated
  26859. from an earlier Guix revision. Nevertheless it lacks the level of
  26860. transparency that we get in the rest of the package dependency graph,
  26861. where Guix always gives us a source-to-binary mapping. Thus, our goal
  26862. is to reduce the set of bootstrap binaries to the bare minimum.
  26863. The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
  26864. on-going projects to do that. One of these is about replacing the
  26865. bootstrap GCC with a sequence of assemblers, interpreters, and compilers
  26866. of increasing complexity, which could be built from source starting from
  26867. a simple and auditable assembler.
  26868. Our first major achievement is the replacement of of GCC, the GNU C Library
  26869. and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
  26870. (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
  26871. and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
  26872. bootstrapped yet and thus we inject them as binary seeds. We call this the
  26873. Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
  26874. binaries! Also, it has eliminated the C compiler binary; i686-linux and
  26875. x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
  26876. Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
  26877. also looking at any other bootstrap binaries. Your help is welcome!
  26878. @node Porting
  26879. @chapter Porting to a New Platform
  26880. As discussed above, the GNU distribution is self-contained, and
  26881. self-containment is achieved by relying on pre-built ``bootstrap
  26882. binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
  26883. operating system kernel, CPU architecture, and application binary
  26884. interface (ABI). Thus, to port the distribution to a platform that is
  26885. not yet supported, one must build those bootstrap binaries, and update
  26886. the @code{(gnu packages bootstrap)} module to use them on that platform.
  26887. Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
  26888. When everything goes well, and assuming the GNU tool chain supports the
  26889. target platform, this can be as simple as running a command like this
  26890. one:
  26891. @example
  26892. guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
  26893. @end example
  26894. For this to work, the @code{glibc-dynamic-linker} procedure in
  26895. @code{(gnu packages bootstrap)} must be augmented to return the right
  26896. file name for libc's dynamic linker on that platform; likewise,
  26897. @code{system->linux-architecture} in @code{(gnu packages linux)} must be
  26898. taught about the new platform.
  26899. Once these are built, the @code{(gnu packages bootstrap)} module needs
  26900. to be updated to refer to these binaries on the target platform. That
  26901. is, the hashes and URLs of the bootstrap tarballs for the new platform
  26902. must be added alongside those of the currently supported platforms. The
  26903. bootstrap Guile tarball is treated specially: it is expected to be
  26904. available locally, and @file{gnu/local.mk} has rules to download it for
  26905. the supported architectures; a rule for the new platform must be added
  26906. as well.
  26907. In practice, there may be some complications. First, it may be that the
  26908. extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
  26909. above) is not recognized by all the GNU tools. Typically, glibc
  26910. recognizes some of these, whereas GCC uses an extra @option{--with-abi}
  26911. configure flag (see @code{gcc.scm} for examples of how to handle this).
  26912. Second, some of the required packages could fail to build for that
  26913. platform. Lastly, the generated binaries could be broken for some
  26914. reason.
  26915. @c *********************************************************************
  26916. @include contributing.texi
  26917. @c *********************************************************************
  26918. @node Acknowledgments
  26919. @chapter Acknowledgments
  26920. Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
  26921. which was designed and
  26922. implemented by Eelco Dolstra, with contributions from other people (see
  26923. the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
  26924. management, and promoted unprecedented features, such as transactional
  26925. package upgrades and rollbacks, per-user profiles, and referentially
  26926. transparent build processes. Without this work, Guix would not exist.
  26927. The Nix-based software distributions, Nixpkgs and NixOS, have also been
  26928. an inspiration for Guix.
  26929. GNU@tie{}Guix itself is a collective work with contributions from a
  26930. number of people. See the @file{AUTHORS} file in Guix for more
  26931. information on these fine people. The @file{THANKS} file lists people
  26932. who have helped by reporting bugs, taking care of the infrastructure,
  26933. providing artwork and themes, making suggestions, and more---thank you!
  26934. @c *********************************************************************
  26935. @node GNU Free Documentation License
  26936. @appendix GNU Free Documentation License
  26937. @cindex license, GNU Free Documentation License
  26938. @include fdl-1.3.texi
  26939. @c *********************************************************************
  26940. @node Concept Index
  26941. @unnumbered Concept Index
  26942. @printindex cp
  26943. @node Programming Index
  26944. @unnumbered Programming Index
  26945. @syncodeindex tp fn
  26946. @syncodeindex vr fn
  26947. @printindex fn
  26948. @bye
  26949. @c Local Variables:
  26950. @c ispell-local-dictionary: "american";
  26951. @c End: