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 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 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 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 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. * Substitute Authentication:: How Guix verifies substitutes.
  200. * Proxy Settings:: How to get substitutes via proxy.
  201. * Substitution Failure:: What happens when substitution fails.
  202. * On Trusting Binaries:: How can you trust that binary blob?
  203. Channels
  204. * Specifying Additional Channels:: Extending the package collection.
  205. * Using a Custom Guix Channel:: Using a customized Guix.
  206. * Replicating Guix:: Running the @emph{exact same} Guix.
  207. * Channel Authentication:: How Guix verifies what it fetches.
  208. * Creating a Channel:: How to write your custom channel.
  209. * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
  210. * Declaring Channel Dependencies:: How to depend on other channels.
  211. * Specifying Channel Authorizations:: Defining channel authors authorizations.
  212. * Primary URL:: Distinguishing mirror to original.
  213. * Writing Channel News:: Communicating information to channel's users.
  214. Development
  215. * Invoking guix environment:: Setting up development environments.
  216. * Invoking guix pack:: Creating software bundles.
  217. * The GCC toolchain:: Working with languages supported by GCC.
  218. * Invoking guix git authenticate:: Authenticating Git repositories.
  219. Programming Interface
  220. * Package Modules:: Packages from the programmer's viewpoint.
  221. * Defining Packages:: Defining new packages.
  222. * Defining Package Variants:: Customizing packages.
  223. * Build Systems:: Specifying how packages are built.
  224. * Build Phases:: Phases of the build process of a package.
  225. * Build Utilities:: Helpers for your package definitions and more.
  226. * The Store:: Manipulating the package store.
  227. * Derivations:: Low-level interface to package derivations.
  228. * The Store Monad:: Purely functional interface to the store.
  229. * G-Expressions:: Manipulating build expressions.
  230. * Invoking guix repl:: Programming Guix in Guile.
  231. Defining Packages
  232. * package Reference:: The package data type.
  233. * origin Reference:: The origin data type.
  234. Utilities
  235. * Invoking guix build:: Building packages from the command line.
  236. * Invoking guix edit:: Editing package definitions.
  237. * Invoking guix download:: Downloading a file and printing its hash.
  238. * Invoking guix hash:: Computing the cryptographic hash of a file.
  239. * Invoking guix import:: Importing package definitions.
  240. * Invoking guix refresh:: Updating package definitions.
  241. * Invoking guix lint:: Finding errors in package definitions.
  242. * Invoking guix size:: Profiling disk usage.
  243. * Invoking guix graph:: Visualizing the graph of packages.
  244. * Invoking guix publish:: Sharing substitutes.
  245. * Invoking guix challenge:: Challenging substitute servers.
  246. * Invoking guix copy:: Copying to and from a remote store.
  247. * Invoking guix container:: Process isolation.
  248. * Invoking guix weather:: Assessing substitute availability.
  249. * Invoking guix processes:: Listing client processes.
  250. Invoking @command{guix build}
  251. * Common Build Options:: Build options for most commands.
  252. * Package Transformation Options:: Creating variants of packages.
  253. * Additional Build Options:: Options specific to 'guix build'.
  254. * Debugging Build Failures:: Real life packaging experience.
  255. System Configuration
  256. * Using the Configuration System:: Customizing your GNU system.
  257. * operating-system Reference:: Detail of operating-system declarations.
  258. * File Systems:: Configuring file system mounts.
  259. * Mapped Devices:: Block device extra processing.
  260. * User Accounts:: Specifying user accounts.
  261. * Keyboard Layout:: How the system interprets key strokes.
  262. * Locales:: Language and cultural convention settings.
  263. * Services:: Specifying system services.
  264. * Setuid Programs:: Programs running with root privileges.
  265. * X.509 Certificates:: Authenticating HTTPS servers.
  266. * Name Service Switch:: Configuring libc's name service switch.
  267. * Initial RAM Disk:: Linux-Libre bootstrapping.
  268. * Bootloader Configuration:: Configuring the boot loader.
  269. * Invoking guix system:: Instantiating a system configuration.
  270. * Invoking guix deploy:: Deploying a system configuration to a remote host.
  271. * Running Guix in a VM:: How to run Guix System in a virtual machine.
  272. * Defining Services:: Adding new service definitions.
  273. Services
  274. * Base Services:: Essential system services.
  275. * Scheduled Job Execution:: The mcron service.
  276. * Log Rotation:: The rottlog service.
  277. * Networking Services:: Network setup, SSH daemon, etc.
  278. * Unattended Upgrades:: Automated system upgrades.
  279. * X Window:: Graphical display.
  280. * Printing Services:: Local and remote printer support.
  281. * Desktop Services:: D-Bus and desktop services.
  282. * Sound Services:: ALSA and Pulseaudio services.
  283. * Database Services:: SQL databases, key-value stores, etc.
  284. * Mail Services:: IMAP, POP3, SMTP, and all that.
  285. * Messaging Services:: Messaging services.
  286. * Telephony Services:: Telephony services.
  287. * Monitoring Services:: Monitoring services.
  288. * Kerberos Services:: Kerberos services.
  289. * LDAP Services:: LDAP services.
  290. * Web Services:: Web servers.
  291. * Certificate Services:: TLS certificates via Let's Encrypt.
  292. * DNS Services:: DNS daemons.
  293. * VPN Services:: VPN daemons.
  294. * Network File System:: NFS related services.
  295. * Continuous Integration:: The Cuirass service.
  296. * Power Management Services:: Extending battery life.
  297. * Audio Services:: The MPD.
  298. * Virtualization Services:: Virtualization services.
  299. * Version Control Services:: Providing remote access to Git repositories.
  300. * Game Services:: Game servers.
  301. * PAM Mount Service:: Service to mount volumes when logging in.
  302. * Guix Services:: Services relating specifically to Guix.
  303. * Linux Services:: Services tied to the Linux kernel.
  304. * Hurd Services:: Services specific for a Hurd System.
  305. * Miscellaneous Services:: Other services.
  306. Defining Services
  307. * Service Composition:: The model for composing services.
  308. * Service Types and Services:: Types and services.
  309. * Service Reference:: API reference.
  310. * Shepherd Services:: A particular type of service.
  311. Installing Debugging Files
  312. * Separate Debug Info:: Installing 'debug' outputs.
  313. * Rebuilding Debug Info:: Building missing debug info.
  314. Bootstrapping
  315. * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
  316. * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
  317. @end detailmenu
  318. @end menu
  319. @c *********************************************************************
  320. @node Introduction
  321. @chapter Introduction
  322. @cindex purpose
  323. GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
  324. using the international phonetic alphabet (IPA).} is a package
  325. management tool for and distribution of the GNU system.
  326. Guix makes it easy for unprivileged
  327. users to install, upgrade, or remove software packages, to roll back to a
  328. previous package set, to build packages from source, and generally
  329. assists with the creation and maintenance of software environments.
  330. @cindex Guix System
  331. @cindex GuixSD, now Guix System
  332. @cindex Guix System Distribution, now Guix System
  333. You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
  334. complements the available tools without interference (@pxref{Installation}),
  335. or you can use it as a standalone operating system distribution,
  336. @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
  337. System Distribution'' or ``GuixSD''. We now consider it makes more sense to
  338. group everything under the ``Guix'' banner since, after all, Guix System is
  339. readily available through the @command{guix system} command, even if you're
  340. using a different distro underneath!}. @xref{GNU Distribution}.
  341. @menu
  342. * Managing Software the Guix Way:: What's special.
  343. * GNU Distribution:: The packages and tools.
  344. @end menu
  345. @node Managing Software the Guix Way
  346. @section Managing Software the Guix Way
  347. @cindex user interfaces
  348. Guix provides a command-line package management interface
  349. (@pxref{Package Management}), tools to help with software development
  350. (@pxref{Development}), command-line utilities for more advanced usage
  351. (@pxref{Utilities}), as well as Scheme programming interfaces
  352. (@pxref{Programming Interface}).
  353. @cindex build daemon
  354. Its @dfn{build daemon} is responsible for building packages on behalf of
  355. users (@pxref{Setting Up the Daemon}) and for downloading pre-built
  356. binaries from authorized sources (@pxref{Substitutes}).
  357. @cindex extensibility of the distribution
  358. @cindex customization, of packages
  359. Guix includes package definitions for many GNU and non-GNU packages, all
  360. of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
  361. user's computing freedom}. It is @emph{extensible}: users can write
  362. their own package definitions (@pxref{Defining Packages}) and make them
  363. available as independent package modules (@pxref{Package Modules}). It
  364. is also @emph{customizable}: users can @emph{derive} specialized package
  365. definitions from existing ones, including from the command line
  366. (@pxref{Package Transformation Options}).
  367. @cindex functional package management
  368. @cindex isolation
  369. Under the hood, Guix implements the @dfn{functional package management}
  370. discipline pioneered by Nix (@pxref{Acknowledgments}).
  371. In Guix, the package build and installation process is seen
  372. as a @emph{function}, in the mathematical sense. That function takes inputs,
  373. such as build scripts, a compiler, and libraries, and
  374. returns an installed package. As a pure function, its result depends
  375. solely on its inputs---for instance, it cannot refer to software or
  376. scripts that were not explicitly passed as inputs. A build function
  377. always produces the same result when passed a given set of inputs. It
  378. cannot alter the environment of the running system in
  379. any way; for instance, it cannot create, modify, or delete files outside
  380. of its build and installation directories. This is achieved by running
  381. build processes in isolated environments (or @dfn{containers}), where only their
  382. explicit inputs are visible.
  383. @cindex store
  384. The result of package build functions is @dfn{cached} in the file
  385. system, in a special directory called @dfn{the store} (@pxref{The
  386. Store}). Each package is installed in a directory of its own in the
  387. store---by default under @file{/gnu/store}. The directory name contains
  388. a hash of all the inputs used to build that package; thus, changing an
  389. input yields a different directory name.
  390. This approach is the foundation for the salient features of Guix: support
  391. for transactional package upgrade and rollback, per-user installation, and
  392. garbage collection of packages (@pxref{Features}).
  393. @node GNU Distribution
  394. @section GNU Distribution
  395. @cindex Guix System
  396. Guix comes with a distribution of the GNU system consisting entirely of
  397. free software@footnote{The term ``free'' here refers to the
  398. @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
  399. users of that software}.}. The
  400. distribution can be installed on its own (@pxref{System Installation}),
  401. but it is also possible to install Guix as a package manager on top of
  402. an installed GNU/Linux system (@pxref{Installation}). When we need to
  403. distinguish between the two, we refer to the standalone distribution as
  404. Guix@tie{}System.
  405. The distribution provides core GNU packages such as GNU libc, GCC, and
  406. Binutils, as well as many GNU and non-GNU applications. The complete
  407. list of available packages can be browsed
  408. @url{https://www.gnu.org/software/guix/packages,on-line} or by
  409. running @command{guix package} (@pxref{Invoking guix package}):
  410. @example
  411. guix package --list-available
  412. @end example
  413. Our goal is to provide a practical 100% free software distribution of
  414. Linux-based and other variants of GNU, with a focus on the promotion and
  415. tight integration of GNU components, and an emphasis on programs and
  416. tools that help users exert that freedom.
  417. Packages are currently available on the following platforms:
  418. @table @code
  419. @item x86_64-linux
  420. Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
  421. @item i686-linux
  422. Intel 32-bit architecture (IA32), Linux-Libre kernel.
  423. @item armhf-linux
  424. ARMv7-A architecture with hard float, Thumb-2 and NEON,
  425. using the EABI hard-float application binary interface (ABI),
  426. and Linux-Libre kernel.
  427. @item aarch64-linux
  428. little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
  429. @item i586-gnu
  430. @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
  431. (IA32).
  432. This configuration is experimental and under development. The easiest
  433. way for you to give it a try is by setting up an instance of
  434. @code{hurd-vm-service-type} on your GNU/Linux machine
  435. (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
  436. @xref{Contributing}, on how to help!
  437. @item mips64el-linux (deprecated)
  438. little-endian 64-bit MIPS processors, specifically the Loongson series,
  439. n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
  440. supported; in particular, there is no ongoing work to ensure that this
  441. architecture still works. Should someone decide they wish to revive this
  442. architecture then the code is still available.
  443. @end table
  444. With Guix@tie{}System, you @emph{declare} all aspects of the operating system
  445. configuration and Guix takes care of instantiating the configuration in a
  446. transactional, reproducible, and stateless fashion (@pxref{System
  447. Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
  448. initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
  449. Manual}), the well-known GNU utilities and tool chain, as well as the
  450. graphical environment or system services of your choice.
  451. Guix System is available on all the above platforms except
  452. @code{mips64el-linux}.
  453. @noindent
  454. For information on porting to other architectures or kernels,
  455. @pxref{Porting}.
  456. Building this distribution is a cooperative effort, and you are invited
  457. to join! @xref{Contributing}, for information about how you can help.
  458. @c *********************************************************************
  459. @node Installation
  460. @chapter Installation
  461. @cindex installing Guix
  462. @quotation Note
  463. We recommend the use of this
  464. @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
  465. shell installer script} to install Guix on top of a running GNU/Linux system,
  466. thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
  467. with the installation of the package manager, which can be done on top of a
  468. running GNU/Linux system. If, instead, you want to install the complete GNU
  469. operating system, @pxref{System Installation}.} The script automates the
  470. download, installation, and initial configuration of Guix. It should be run
  471. as the root user.
  472. @end quotation
  473. @cindex foreign distro
  474. @cindex directories related to foreign distro
  475. When installed on a foreign distro, GNU@tie{}Guix complements the available
  476. tools without interference. Its data lives exclusively in two directories,
  477. usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
  478. such as @file{/etc}, are left untouched.
  479. Once installed, Guix can be updated by running @command{guix pull}
  480. (@pxref{Invoking guix pull}).
  481. If you prefer to perform the installation steps manually or want to tweak
  482. them, you may find the following subsections useful. They describe the
  483. software requirements of Guix, as well as how to install it manually and get
  484. ready to use it.
  485. @menu
  486. * Binary Installation:: Getting Guix running in no time!
  487. * Requirements:: Software needed to build and run Guix.
  488. * Running the Test Suite:: Testing Guix.
  489. * Setting Up the Daemon:: Preparing the build daemon's environment.
  490. * Invoking guix-daemon:: Running the build daemon.
  491. * Application Setup:: Application-specific setup.
  492. * Upgrading Guix:: Upgrading Guix and its build daemon.
  493. @end menu
  494. @node Binary Installation
  495. @section Binary Installation
  496. @cindex installing Guix from binaries
  497. @cindex installer script
  498. This section describes how to install Guix on an arbitrary system from a
  499. self-contained tarball providing binaries for Guix and for all its
  500. dependencies. This is often quicker than installing from source, which
  501. is described in the next sections. The only requirement is to have
  502. GNU@tie{}tar and Xz.
  503. @c Note duplicated from the ``Installation'' node.
  504. @quotation Note
  505. We recommend the use of this
  506. @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
  507. shell installer script}. The script automates the download, installation, and
  508. initial configuration steps described below. It should be run as the root
  509. user. As root, you can thus run this:
  510. @example
  511. cd /tmp
  512. wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
  513. chmod +x guix-install.sh
  514. ./guix-install.sh
  515. @end example
  516. When you're done, @pxref{Application Setup} for extra configuration you
  517. might need, and @ref{Getting Started} for your first steps!
  518. @end quotation
  519. Installing goes along these lines:
  520. @enumerate
  521. @item
  522. @cindex downloading Guix binary
  523. Download the binary tarball from
  524. @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
  525. where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
  526. @code{i686} (32-bits) machine already running the kernel Linux, and so on
  527. (@pxref{GNU Distribution}).
  528. @c The following is somewhat duplicated in ``System Installation''.
  529. Make sure to download the associated @file{.sig} file and to verify the
  530. authenticity of the tarball against it, along these lines:
  531. @example
  532. $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
  533. $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
  534. @end example
  535. If that command fails because you do not have the required public key,
  536. then run this command to import it:
  537. @example
  538. $ wget @value{OPENPGP-SIGNING-KEY-URL} \
  539. -qO - | gpg --import -
  540. @end example
  541. @noindent
  542. and rerun the @code{gpg --verify} command.
  543. Take note that a warning like ``This key is not certified with a trusted
  544. signature!'' is normal.
  545. @c end authentication part
  546. @item
  547. Now, you need to become the @code{root} user. Depending on your distribution,
  548. you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
  549. @example
  550. # cd /tmp
  551. # tar --warning=no-timestamp -xf \
  552. /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
  553. # mv var/guix /var/ && mv gnu /
  554. @end example
  555. This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
  556. The latter contains a ready-to-use profile for @code{root} (see next
  557. step).
  558. Do @emph{not} unpack the tarball on a working Guix system since that
  559. would overwrite its own essential files.
  560. The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
  561. not emit warnings about ``implausibly old time stamps'' (such
  562. warnings were triggered by GNU@tie{}tar 1.26 and older; recent
  563. versions are fine).
  564. They stem from the fact that all the
  565. files in the archive have their modification time set to 1 (which
  566. means January 1st, 1970). This is done on purpose to make sure the
  567. archive content is independent of its creation time, thus making it
  568. reproducible.
  569. @item
  570. Make the profile available under @file{~root/.config/guix/current}, which is
  571. where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
  572. @example
  573. # mkdir -p ~root/.config/guix
  574. # ln -sf /var/guix/profiles/per-user/root/current-guix \
  575. ~root/.config/guix/current
  576. @end example
  577. Source @file{etc/profile} to augment @env{PATH} and other relevant
  578. environment variables:
  579. @example
  580. # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
  581. source $GUIX_PROFILE/etc/profile
  582. @end example
  583. @item
  584. Create the group and user accounts for build users as explained below
  585. (@pxref{Build Environment Setup}).
  586. @item
  587. Run the daemon, and set it to automatically start on boot.
  588. If your host distro uses the systemd init system, this can be achieved
  589. with these commands:
  590. @c Versions of systemd that supported symlinked service files are not
  591. @c yet widely deployed, so we should suggest that users copy the service
  592. @c files into place.
  593. @c
  594. @c See this thread for more information:
  595. @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
  596. @example
  597. # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
  598. ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
  599. /etc/systemd/system/
  600. # systemctl enable --now gnu-store.mount guix-daemon
  601. @end example
  602. If your host distro uses the Upstart init system:
  603. @example
  604. # initctl reload-configuration
  605. # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
  606. /etc/init/
  607. # start guix-daemon
  608. @end example
  609. Otherwise, you can still start the daemon manually with:
  610. @example
  611. # ~root/.config/guix/current/bin/guix-daemon \
  612. --build-users-group=guixbuild
  613. @end example
  614. @item
  615. Make the @command{guix} command available to other users on the machine,
  616. for instance with:
  617. @example
  618. # mkdir -p /usr/local/bin
  619. # cd /usr/local/bin
  620. # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
  621. @end example
  622. It is also a good idea to make the Info version of this manual available
  623. there:
  624. @example
  625. # mkdir -p /usr/local/share/info
  626. # cd /usr/local/share/info
  627. # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
  628. do ln -s $i ; done
  629. @end example
  630. That way, assuming @file{/usr/local/share/info} is in the search path,
  631. running @command{info guix} will open this manual (@pxref{Other Info
  632. Directories,,, texinfo, GNU Texinfo}, for more details on changing the
  633. Info search path).
  634. @item
  635. @cindex substitutes, authorization thereof
  636. To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
  637. (@pxref{Substitutes}), authorize them:
  638. @example
  639. # guix archive --authorize < \
  640. ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
  641. @end example
  642. @item
  643. Each user may need to perform a few additional steps to make their Guix
  644. environment ready for use, @pxref{Application Setup}.
  645. @end enumerate
  646. Voilà, the installation is complete!
  647. You can confirm that Guix is working by installing a sample package into
  648. the root profile:
  649. @example
  650. # guix install hello
  651. @end example
  652. The binary installation tarball can be (re)produced and verified simply
  653. by running the following command in the Guix source tree:
  654. @example
  655. make guix-binary.@var{system}.tar.xz
  656. @end example
  657. @noindent
  658. ...@: which, in turn, runs:
  659. @example
  660. guix pack -s @var{system} --localstatedir \
  661. --profile-name=current-guix guix
  662. @end example
  663. @xref{Invoking guix pack}, for more info on this handy tool.
  664. @node Requirements
  665. @section Requirements
  666. This section lists requirements when building Guix from source. The
  667. build procedure for Guix is the same as for other GNU software, and is
  668. not covered here. Please see the files @file{README} and @file{INSTALL}
  669. in the Guix source tree for additional details.
  670. @cindex official website
  671. GNU Guix is available for download from its website at
  672. @url{https://www.gnu.org/software/guix/}.
  673. GNU Guix depends on the following packages:
  674. @itemize
  675. @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
  676. 2.2.x;
  677. @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
  678. 0.1.0 or later;
  679. @item
  680. @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
  681. (@pxref{Guile Preparations, how to install the GnuTLS bindings for
  682. Guile,, gnutls-guile, GnuTLS-Guile});
  683. @item
  684. @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
  685. or later;
  686. @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib};
  687. @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
  688. @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
  689. @item
  690. @c FIXME: Specify a version number once a release has been made.
  691. @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
  692. or later;
  693. @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
  694. 4.3.0 or later;
  695. @item @url{https://www.gnu.org/software/make/, GNU Make}.
  696. @end itemize
  697. The following dependencies are optional:
  698. @itemize
  699. @item
  700. @c Note: We need at least 0.13.0 for #:nodelay.
  701. Support for build offloading (@pxref{Daemon Offload Setup}) and
  702. @command{guix copy} (@pxref{Invoking guix copy}) depends on
  703. @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
  704. version 0.13.0 or later.
  705. @item
  706. @uref{https://notabug.org/guile-zstd/guile-zstd, Guile-zstd}, for zstd
  707. compression and decompression in @command{guix publish} and for
  708. substitutes (@pxref{Invoking guix publish}).
  709. @item
  710. @uref{https://ngyro.com/software/guile-semver.html, Guile-Semver} for
  711. the @code{crate} importer (@pxref{Invoking guix import}).
  712. @item
  713. When @url{http://www.bzip.org, libbz2} is available,
  714. @command{guix-daemon} can use it to compress build logs.
  715. @end itemize
  716. Unless @option{--disable-daemon} was passed to @command{configure}, the
  717. following packages are also needed:
  718. @itemize
  719. @item @url{https://gnupg.org/, GNU libgcrypt};
  720. @item @url{https://sqlite.org, SQLite 3};
  721. @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
  722. C++11 standard.
  723. @end itemize
  724. @cindex state directory
  725. When configuring Guix on a system that already has a Guix installation,
  726. be sure to specify the same state directory as the existing installation
  727. using the @option{--localstatedir} option of the @command{configure}
  728. script (@pxref{Directory Variables, @code{localstatedir},, standards,
  729. GNU Coding Standards}). Usually, this @var{localstatedir} option is
  730. set to the value @file{/var}. The @command{configure} script protects
  731. against unintended misconfiguration of @var{localstatedir} so you do not
  732. inadvertently corrupt your store (@pxref{The Store}).
  733. @node Running the Test Suite
  734. @section Running the Test Suite
  735. @cindex test suite
  736. After a successful @command{configure} and @code{make} run, it is a good
  737. idea to run the test suite. It can help catch issues with the setup or
  738. environment, or bugs in Guix itself---and really, reporting test
  739. failures is a good way to help improve the software. To run the test
  740. suite, type:
  741. @example
  742. make check
  743. @end example
  744. Test cases can run in parallel: you can use the @code{-j} option of
  745. GNU@tie{}make to speed things up. The first run may take a few minutes
  746. on a recent machine; subsequent runs will be faster because the store
  747. that is created for test purposes will already have various things in
  748. cache.
  749. It is also possible to run a subset of the tests by defining the
  750. @code{TESTS} makefile variable as in this example:
  751. @example
  752. make check TESTS="tests/store.scm tests/cpio.scm"
  753. @end example
  754. By default, tests results are displayed at a file level. In order to
  755. see the details of every individual test cases, it is possible to define
  756. the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
  757. @example
  758. make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
  759. @end example
  760. Upon failure, please email @email{bug-guix@@gnu.org} and attach the
  761. @file{test-suite.log} file. Please specify the Guix version being used
  762. as well as version numbers of the dependencies (@pxref{Requirements}) in
  763. your message.
  764. Guix also comes with a whole-system test suite that tests complete
  765. Guix System instances. It can only run on systems where
  766. Guix is already installed, using:
  767. @example
  768. make check-system
  769. @end example
  770. @noindent
  771. or, again, by defining @code{TESTS} to select a subset of tests to run:
  772. @example
  773. make check-system TESTS="basic mcron"
  774. @end example
  775. These system tests are defined in the @code{(gnu tests @dots{})}
  776. modules. They work by running the operating systems under test with
  777. lightweight instrumentation in a virtual machine (VM). They can be
  778. computationally intensive or rather cheap, depending on whether
  779. substitutes are available for their dependencies (@pxref{Substitutes}).
  780. Some of them require a lot of storage space to hold VM images.
  781. Again in case of test failures, please send @email{bug-guix@@gnu.org}
  782. all the details.
  783. @node Setting Up the Daemon
  784. @section Setting Up the Daemon
  785. @cindex daemon
  786. Operations such as building a package or running the garbage collector
  787. are all performed by a specialized process, the @dfn{build daemon}, on
  788. behalf of clients. Only the daemon may access the store and its
  789. associated database. Thus, any operation that manipulates the store
  790. goes through the daemon. For instance, command-line tools such as
  791. @command{guix package} and @command{guix build} communicate with the
  792. daemon (@i{via} remote procedure calls) to instruct it what to do.
  793. The following sections explain how to prepare the build daemon's
  794. environment. See also @ref{Substitutes}, for information on how to allow
  795. the daemon to download pre-built binaries.
  796. @menu
  797. * Build Environment Setup:: Preparing the isolated build environment.
  798. * Daemon Offload Setup:: Offloading builds to remote machines.
  799. * SELinux Support:: Using an SELinux policy for the daemon.
  800. @end menu
  801. @node Build Environment Setup
  802. @subsection Build Environment Setup
  803. @cindex build environment
  804. In a standard multi-user setup, Guix and its daemon---the
  805. @command{guix-daemon} program---are installed by the system
  806. administrator; @file{/gnu/store} is owned by @code{root} and
  807. @command{guix-daemon} runs as @code{root}. Unprivileged users may use
  808. Guix tools to build packages or otherwise access the store, and the
  809. daemon will do it on their behalf, ensuring that the store is kept in a
  810. consistent state, and allowing built packages to be shared among users.
  811. @cindex build users
  812. When @command{guix-daemon} runs as @code{root}, you may not want package
  813. build processes themselves to run as @code{root} too, for obvious
  814. security reasons. To avoid that, a special pool of @dfn{build users}
  815. should be created for use by build processes started by the daemon.
  816. These build users need not have a shell and a home directory: they will
  817. just be used when the daemon drops @code{root} privileges in build
  818. processes. Having several such users allows the daemon to launch
  819. distinct build processes under separate UIDs, which guarantees that they
  820. do not interfere with each other---an essential feature since builds are
  821. regarded as pure functions (@pxref{Introduction}).
  822. On a GNU/Linux system, a build user pool may be created like this (using
  823. Bash syntax and the @code{shadow} commands):
  824. @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
  825. @c for why `-G' is needed.
  826. @example
  827. # groupadd --system guixbuild
  828. # for i in `seq -w 1 10`;
  829. do
  830. useradd -g guixbuild -G guixbuild \
  831. -d /var/empty -s `which nologin` \
  832. -c "Guix build user $i" --system \
  833. guixbuilder$i;
  834. done
  835. @end example
  836. @noindent
  837. The number of build users determines how many build jobs may run in
  838. parallel, as specified by the @option{--max-jobs} option
  839. (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
  840. @command{guix system vm} and related commands, you may need to add the
  841. build users to the @code{kvm} group so they can access @file{/dev/kvm},
  842. using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
  843. (@pxref{Invoking guix system}).
  844. The @code{guix-daemon} program may then be run as @code{root} with the
  845. following command@footnote{If your machine uses the systemd init system,
  846. dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
  847. file in @file{/etc/systemd/system} will ensure that
  848. @command{guix-daemon} is automatically started. Similarly, if your
  849. machine uses the Upstart init system, drop the
  850. @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
  851. file in @file{/etc/init}.}:
  852. @example
  853. # guix-daemon --build-users-group=guixbuild
  854. @end example
  855. @cindex chroot
  856. @noindent
  857. This way, the daemon starts build processes in a chroot, under one of
  858. the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
  859. environment contains nothing but:
  860. @c Keep this list in sync with libstore/build.cc! -----------------------
  861. @itemize
  862. @item
  863. a minimal @code{/dev} directory, created mostly independently from the
  864. host @code{/dev}@footnote{``Mostly'', because while the set of files
  865. that appear in the chroot's @code{/dev} is fixed, most of these files
  866. can only be created if the host has them.};
  867. @item
  868. the @code{/proc} directory; it only shows the processes of the container
  869. since a separate PID name space is used;
  870. @item
  871. @file{/etc/passwd} with an entry for the current user and an entry for
  872. user @file{nobody};
  873. @item
  874. @file{/etc/group} with an entry for the user's group;
  875. @item
  876. @file{/etc/hosts} with an entry that maps @code{localhost} to
  877. @code{127.0.0.1};
  878. @item
  879. a writable @file{/tmp} directory.
  880. @end itemize
  881. You can influence the directory where the daemon stores build trees
  882. @i{via} the @env{TMPDIR} environment variable. However, the build tree
  883. within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
  884. where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
  885. This way, the value of @env{TMPDIR} does not leak inside build
  886. environments, which avoids discrepancies in cases where build processes
  887. capture the name of their build tree.
  888. @vindex http_proxy
  889. @vindex https_proxy
  890. The daemon also honors the @env{http_proxy} and @env{https_proxy}
  891. environment variables for HTTP and HTTPS downloads it performs, be it
  892. for fixed-output derivations (@pxref{Derivations}) or for substitutes
  893. (@pxref{Substitutes}).
  894. If you are installing Guix as an unprivileged user, it is still possible
  895. to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
  896. However, build processes will not be isolated from one another, and not
  897. from the rest of the system. Thus, build processes may interfere with
  898. each other, and may access programs, libraries, and other files
  899. available on the system---making it much harder to view them as
  900. @emph{pure} functions.
  901. @node Daemon Offload Setup
  902. @subsection Using the Offload Facility
  903. @cindex offloading
  904. @cindex build hook
  905. When desired, the build daemon can @dfn{offload} derivation builds to
  906. other machines running Guix, using the @code{offload} @dfn{build
  907. hook}@footnote{This feature is available only when
  908. @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
  909. present.}. When that feature is enabled, a list of user-specified build
  910. machines is read from @file{/etc/guix/machines.scm}; every time a build
  911. is requested, for instance via @code{guix build}, the daemon attempts to
  912. offload it to one of the machines that satisfy the constraints of the
  913. derivation, in particular its system types---e.g., @code{x86_64-linux}.
  914. A single machine can have multiple system types, either because its
  915. architecture natively supports it, via emulation
  916. (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
  917. or both. Missing prerequisites for the build are
  918. copied over SSH to the target machine, which then proceeds with the
  919. build; upon success the output(s) of the build are copied back to the
  920. initial machine. The offload facility comes with a basic scheduler that
  921. attempts to select the best machine. The best machine is chosen among
  922. the available machines based on criteria such as:
  923. @enumerate
  924. @item
  925. The availability of a build slot. A build machine can have as many
  926. build slots (connections) as the value of the @code{parallel-builds}
  927. field of its @code{build-machine} object.
  928. @item
  929. Its relative speed, as defined via the @code{speed} field of its
  930. @code{build-machine} object.
  931. @item
  932. Its load. The normalized machine load must be lower than a threshold
  933. value, configurable via the @code{overload-threshold} field of its
  934. @code{build-machine} object.
  935. @item
  936. Disk space availability. More than a 100 MiB must be available.
  937. @end enumerate
  938. The @file{/etc/guix/machines.scm} file typically looks like this:
  939. @lisp
  940. (list (build-machine
  941. (name "eightysix.example.org")
  942. (systems (list "x86_64-linux" "i686-linux"))
  943. (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
  944. (user "bob")
  945. (speed 2.)) ;incredibly fast!
  946. (build-machine
  947. (name "armeight.example.org")
  948. (systems (list "aarch64-linux"))
  949. (host-key "ssh-rsa AAAAB3Nza@dots{}")
  950. (user "alice")
  951. (private-key
  952. (string-append (getenv "HOME")
  953. "/.ssh/identity-for-guix"))))
  954. @end lisp
  955. @noindent
  956. In the example above we specify a list of two build machines, one for
  957. the @code{x86_64} and @code{i686} architectures and one for the
  958. @code{aarch64} architecture.
  959. In fact, this file is---not surprisingly!---a Scheme file that is
  960. evaluated when the @code{offload} hook is started. Its return value
  961. must be a list of @code{build-machine} objects. While this example
  962. shows a fixed list of build machines, one could imagine, say, using
  963. DNS-SD to return a list of potential build machines discovered in the
  964. local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
  965. Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
  966. detailed below.
  967. @deftp {Data Type} build-machine
  968. This data type represents build machines to which the daemon may offload
  969. builds. The important fields are:
  970. @table @code
  971. @item name
  972. The host name of the remote machine.
  973. @item systems
  974. The system types the remote machine supports---e.g., @code{(list
  975. "x86_64-linux" "i686-linux")}.
  976. @item user
  977. The user account to use when connecting to the remote machine over SSH.
  978. Note that the SSH key pair must @emph{not} be passphrase-protected, to
  979. allow non-interactive logins.
  980. @item host-key
  981. This must be the machine's SSH @dfn{public host key} in OpenSSH format.
  982. This is used to authenticate the machine when we connect to it. It is a
  983. long string that looks like this:
  984. @example
  985. ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
  986. @end example
  987. If the machine is running the OpenSSH daemon, @command{sshd}, the host
  988. key can be found in a file such as
  989. @file{/etc/ssh/ssh_host_ed25519_key.pub}.
  990. If the machine is running the SSH daemon of GNU@tie{}lsh,
  991. @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
  992. similar file. It can be converted to the OpenSSH format using
  993. @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
  994. @example
  995. $ lsh-export-key --openssh < /etc/lsh/host-key.pub
  996. ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
  997. @end example
  998. @end table
  999. A number of optional fields may be specified:
  1000. @table @asis
  1001. @item @code{port} (default: @code{22})
  1002. Port number of SSH server on the machine.
  1003. @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
  1004. The SSH private key file to use when connecting to the machine, in
  1005. OpenSSH format. This key must not be protected with a passphrase.
  1006. Note that the default value is the private key @emph{of the root
  1007. account}. Make sure it exists if you use the default.
  1008. @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
  1009. @itemx @code{compression-level} (default: @code{3})
  1010. The SSH-level compression methods and compression level requested.
  1011. Note that offloading relies on SSH compression to reduce bandwidth usage
  1012. when transferring files to and from build machines.
  1013. @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
  1014. File name of the Unix-domain socket @command{guix-daemon} is listening
  1015. to on that machine.
  1016. @item @code{overload-threshold} (default: @code{0.6})
  1017. The load threshold above which a potential offload machine is
  1018. disregarded by the offload scheduler. The value roughly translates to
  1019. the total processor usage of the build machine, ranging from 0.0 (0%) to
  1020. 1.0 (100%). It can also be disabled by setting
  1021. @code{overload-threshold} to @code{#f}.
  1022. @item @code{parallel-builds} (default: @code{1})
  1023. The number of builds that may run in parallel on the machine.
  1024. @item @code{speed} (default: @code{1.0})
  1025. A ``relative speed factor''. The offload scheduler will tend to prefer
  1026. machines with a higher speed factor.
  1027. @item @code{features} (default: @code{'()})
  1028. A list of strings denoting specific features supported by the machine.
  1029. An example is @code{"kvm"} for machines that have the KVM Linux modules
  1030. and corresponding hardware support. Derivations can request features by
  1031. name, and they will be scheduled on matching build machines.
  1032. @end table
  1033. @end deftp
  1034. The @command{guix} command must be in the search path on the build
  1035. machines. You can check whether this is the case by running:
  1036. @example
  1037. ssh build-machine guix repl --version
  1038. @end example
  1039. There is one last thing to do once @file{machines.scm} is in place. As
  1040. explained above, when offloading, files are transferred back and forth
  1041. between the machine stores. For this to work, you first need to
  1042. generate a key pair on each machine to allow the daemon to export signed
  1043. archives of files from the store (@pxref{Invoking guix archive}):
  1044. @example
  1045. # guix archive --generate-key
  1046. @end example
  1047. @noindent
  1048. Each build machine must authorize the key of the master machine so that
  1049. it accepts store items it receives from the master:
  1050. @example
  1051. # guix archive --authorize < master-public-key.txt
  1052. @end example
  1053. @noindent
  1054. Likewise, the master machine must authorize the key of each build machine.
  1055. All the fuss with keys is here to express pairwise mutual trust
  1056. relations between the master and the build machines. Concretely, when
  1057. the master receives files from a build machine (and @i{vice versa}), its
  1058. build daemon can make sure they are genuine, have not been tampered
  1059. with, and that they are signed by an authorized key.
  1060. @cindex offload test
  1061. To test whether your setup is operational, run this command on the
  1062. master node:
  1063. @example
  1064. # guix offload test
  1065. @end example
  1066. This will attempt to connect to each of the build machines specified in
  1067. @file{/etc/guix/machines.scm}, make sure Guix is
  1068. available on each machine, attempt to export to the machine and import
  1069. from it, and report any error in the process.
  1070. If you want to test a different machine file, just specify it on the
  1071. command line:
  1072. @example
  1073. # guix offload test machines-qualif.scm
  1074. @end example
  1075. Last, you can test the subset of the machines whose name matches a
  1076. regular expression like this:
  1077. @example
  1078. # guix offload test machines.scm '\.gnu\.org$'
  1079. @end example
  1080. @cindex offload status
  1081. To display the current load of all build hosts, run this command on the
  1082. main node:
  1083. @example
  1084. # guix offload status
  1085. @end example
  1086. @node SELinux Support
  1087. @subsection SELinux Support
  1088. @cindex SELinux, daemon policy
  1089. @cindex mandatory access control, SELinux
  1090. @cindex security, guix-daemon
  1091. Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
  1092. can be installed on a system where SELinux is enabled, in order to label
  1093. Guix files and to specify the expected behavior of the daemon. Since
  1094. Guix System does not provide an SELinux base policy, the daemon policy cannot
  1095. be used on Guix System.
  1096. @subsubsection Installing the SELinux policy
  1097. @cindex SELinux, policy installation
  1098. To install the policy run this command as root:
  1099. @example
  1100. semodule -i etc/guix-daemon.cil
  1101. @end example
  1102. Then relabel the file system with @code{restorecon} or by a different
  1103. mechanism provided by your system.
  1104. Once the policy is installed, the file system has been relabeled, and
  1105. the daemon has been restarted, it should be running in the
  1106. @code{guix_daemon_t} context. You can confirm this with the following
  1107. command:
  1108. @example
  1109. ps -Zax | grep guix-daemon
  1110. @end example
  1111. Monitor the SELinux log files as you run a command like @code{guix build
  1112. hello} to convince yourself that SELinux permits all necessary
  1113. operations.
  1114. @subsubsection Limitations
  1115. @cindex SELinux, limitations
  1116. This policy is not perfect. Here is a list of limitations or quirks
  1117. that should be considered when deploying the provided SELinux policy for
  1118. the Guix daemon.
  1119. @enumerate
  1120. @item
  1121. @code{guix_daemon_socket_t} isn’t actually used. None of the socket
  1122. operations involve contexts that have anything to do with
  1123. @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
  1124. but it would be preferrable to define socket rules for only this label.
  1125. @item
  1126. @code{guix gc} cannot access arbitrary links to profiles. By design,
  1127. the file label of the destination of a symlink is independent of the
  1128. file label of the link itself. Although all profiles under
  1129. $localstatedir are labelled, the links to these profiles inherit the
  1130. label of the directory they are in. For links in the user’s home
  1131. directory this will be @code{user_home_t}. But for links from the root
  1132. user’s home directory, or @file{/tmp}, or the HTTP server’s working
  1133. directory, etc, this won’t work. @code{guix gc} would be prevented from
  1134. reading and following these links.
  1135. @item
  1136. The daemon’s feature to listen for TCP connections might no longer work.
  1137. This might require extra rules, because SELinux treats network sockets
  1138. differently from files.
  1139. @item
  1140. Currently all files with a name matching the regular expression
  1141. @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
  1142. label @code{guix_daemon_exec_t}; this means that @emph{any} file with
  1143. that name in any profile would be permitted to run in the
  1144. @code{guix_daemon_t} domain. This is not ideal. An attacker could
  1145. build a package that provides this executable and convince a user to
  1146. install and run it, which lifts it into the @code{guix_daemon_t} domain.
  1147. At that point SELinux could not prevent it from accessing files that are
  1148. allowed for processes in that domain.
  1149. You will need to relabel the store directory after all upgrades to
  1150. @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
  1151. store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
  1152. or by other means provided by your operating system.
  1153. We could generate a much more restrictive policy at installation time,
  1154. so that only the @emph{exact} file name of the currently installed
  1155. @code{guix-daemon} executable would be labelled with
  1156. @code{guix_daemon_exec_t}, instead of using a broad regular expression.
  1157. The downside is that root would have to install or upgrade the policy at
  1158. installation time whenever the Guix package that provides the
  1159. effectively running @code{guix-daemon} executable is upgraded.
  1160. @end enumerate
  1161. @node Invoking guix-daemon
  1162. @section Invoking @command{guix-daemon}
  1163. The @command{guix-daemon} program implements all the functionality to
  1164. access the store. This includes launching build processes, running the
  1165. garbage collector, querying the availability of a build result, etc. It
  1166. is normally run as @code{root} like this:
  1167. @example
  1168. # guix-daemon --build-users-group=guixbuild
  1169. @end example
  1170. @noindent
  1171. For details on how to set it up, @pxref{Setting Up the Daemon}.
  1172. @cindex chroot
  1173. @cindex container, build environment
  1174. @cindex build environment
  1175. @cindex reproducible builds
  1176. By default, @command{guix-daemon} launches build processes under
  1177. different UIDs, taken from the build group specified with
  1178. @option{--build-users-group}. In addition, each build process is run in a
  1179. chroot environment that only contains the subset of the store that the
  1180. build process depends on, as specified by its derivation
  1181. (@pxref{Programming Interface, derivation}), plus a set of specific
  1182. system directories. By default, the latter contains @file{/dev} and
  1183. @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
  1184. @dfn{container}: in addition to having its own file system tree, it has
  1185. a separate mount name space, its own PID name space, network name space,
  1186. etc. This helps achieve reproducible builds (@pxref{Features}).
  1187. When the daemon performs a build on behalf of the user, it creates a
  1188. build directory under @file{/tmp} or under the directory specified by
  1189. its @env{TMPDIR} environment variable. This directory is shared with
  1190. the container for the duration of the build, though within the container,
  1191. the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
  1192. The build directory is automatically deleted upon completion, unless the
  1193. build failed and the client specified @option{--keep-failed}
  1194. (@pxref{Invoking guix build, @option{--keep-failed}}).
  1195. The daemon listens for connections and spawns one sub-process for each session
  1196. started by a client (one of the @command{guix} sub-commands). The
  1197. @command{guix processes} command allows you to get an overview of the activity
  1198. on your system by viewing each of the active sessions and clients.
  1199. @xref{Invoking guix processes}, for more information.
  1200. The following command-line options are supported:
  1201. @table @code
  1202. @item --build-users-group=@var{group}
  1203. Take users from @var{group} to run build processes (@pxref{Setting Up
  1204. the Daemon, build users}).
  1205. @item --no-substitutes
  1206. @cindex substitutes
  1207. Do not use substitutes for build products. That is, always build things
  1208. locally instead of allowing downloads of pre-built binaries
  1209. (@pxref{Substitutes}).
  1210. When the daemon runs with @option{--no-substitutes}, clients can still
  1211. explicitly enable substitution @i{via} the @code{set-build-options}
  1212. remote procedure call (@pxref{The Store}).
  1213. @anchor{daemon-substitute-urls}
  1214. @item --substitute-urls=@var{urls}
  1215. Consider @var{urls} the default whitespace-separated list of substitute
  1216. source URLs. When this option is omitted,
  1217. @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
  1218. This means that substitutes may be downloaded from @var{urls}, as long
  1219. as they are signed by a trusted signature (@pxref{Substitutes}).
  1220. @xref{Getting Substitutes from Other Servers}, for more information on
  1221. how to configure the daemon to get substitutes from other servers.
  1222. @cindex offloading
  1223. @item --no-offload
  1224. Do not use offload builds to other machines (@pxref{Daemon Offload
  1225. Setup}). That is, always build things locally instead of offloading
  1226. builds to remote machines.
  1227. @item --cache-failures
  1228. Cache build failures. By default, only successful builds are cached.
  1229. When this option is used, @command{guix gc --list-failures} can be used
  1230. to query the set of store items marked as failed; @command{guix gc
  1231. --clear-failures} removes store items from the set of cached failures.
  1232. @xref{Invoking guix gc}.
  1233. @item --cores=@var{n}
  1234. @itemx -c @var{n}
  1235. Use @var{n} CPU cores to build each derivation; @code{0} means as many
  1236. as available.
  1237. The default value is @code{0}, but it may be overridden by clients, such
  1238. as the @option{--cores} option of @command{guix build} (@pxref{Invoking
  1239. guix build}).
  1240. The effect is to define the @env{NIX_BUILD_CORES} environment variable
  1241. in the build process, which can then use it to exploit internal
  1242. parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
  1243. @item --max-jobs=@var{n}
  1244. @itemx -M @var{n}
  1245. Allow at most @var{n} build jobs in parallel. The default value is
  1246. @code{1}. Setting it to @code{0} means that no builds will be performed
  1247. locally; instead, the daemon will offload builds (@pxref{Daemon Offload
  1248. Setup}), or simply fail.
  1249. @item --max-silent-time=@var{seconds}
  1250. When the build or substitution process remains silent for more than
  1251. @var{seconds}, terminate it and report a build failure.
  1252. The default value is @code{0}, which disables the timeout.
  1253. The value specified here can be overridden by clients (@pxref{Common
  1254. Build Options, @option{--max-silent-time}}).
  1255. @item --timeout=@var{seconds}
  1256. Likewise, when the build or substitution process lasts for more than
  1257. @var{seconds}, terminate it and report a build failure.
  1258. The default value is @code{0}, which disables the timeout.
  1259. The value specified here can be overridden by clients (@pxref{Common
  1260. Build Options, @option{--timeout}}).
  1261. @item --rounds=@var{N}
  1262. Build each derivation @var{n} times in a row, and raise an error if
  1263. consecutive build results are not bit-for-bit identical. Note that this
  1264. setting can be overridden by clients such as @command{guix build}
  1265. (@pxref{Invoking guix build}).
  1266. When used in conjunction with @option{--keep-failed}, the differing
  1267. output is kept in the store, under @file{/gnu/store/@dots{}-check}.
  1268. This makes it easy to look for differences between the two results.
  1269. @item --debug
  1270. Produce debugging output.
  1271. This is useful to debug daemon start-up issues, but then it may be
  1272. overridden by clients, for example the @option{--verbosity} option of
  1273. @command{guix build} (@pxref{Invoking guix build}).
  1274. @item --chroot-directory=@var{dir}
  1275. Add @var{dir} to the build chroot.
  1276. Doing this may change the result of build processes---for instance if
  1277. they use optional dependencies found in @var{dir} when it is available,
  1278. and not otherwise. For that reason, it is not recommended to do so.
  1279. Instead, make sure that each derivation declares all the inputs that it
  1280. needs.
  1281. @item --disable-chroot
  1282. Disable chroot builds.
  1283. Using this option is not recommended since, again, it would allow build
  1284. processes to gain access to undeclared dependencies. It is necessary,
  1285. though, when @command{guix-daemon} is running under an unprivileged user
  1286. account.
  1287. @item --log-compression=@var{type}
  1288. Compress build logs according to @var{type}, one of @code{gzip},
  1289. @code{bzip2}, or @code{none}.
  1290. Unless @option{--lose-logs} is used, all the build logs are kept in the
  1291. @var{localstatedir}. To save space, the daemon automatically compresses
  1292. them with Bzip2 by default.
  1293. @item --discover[=yes|no]
  1294. Whether to discover substitute servers on the local network using mDNS
  1295. and DNS-SD.
  1296. This feature is still experimental. However, here are a few
  1297. considerations.
  1298. @enumerate
  1299. @item
  1300. It might be faster/less expensive than fetching from remote servers;
  1301. @item
  1302. There are no security risks, only genuine substitutes will be used
  1303. (@pxref{Substitute Authentication});
  1304. @item
  1305. An attacker advertising @command{guix publish} on your LAN cannot serve
  1306. you malicious binaries, but they can learn what software you’re
  1307. installing;
  1308. @item
  1309. Servers may serve substitute over HTTP, unencrypted, so anyone on the
  1310. LAN can see what software you’re installing.
  1311. @end enumerate
  1312. It is also possible to enable or disable substitute server discovery at
  1313. run-time by running:
  1314. @example
  1315. herd discover guix-daemon on
  1316. herd discover guix-daemon off
  1317. @end example
  1318. @item --disable-deduplication
  1319. @cindex deduplication
  1320. Disable automatic file ``deduplication'' in the store.
  1321. By default, files added to the store are automatically ``deduplicated'':
  1322. if a newly added file is identical to another one found in the store,
  1323. the daemon makes the new file a hard link to the other file. This can
  1324. noticeably reduce disk usage, at the expense of slightly increased
  1325. input/output load at the end of a build process. This option disables
  1326. this optimization.
  1327. @item --gc-keep-outputs[=yes|no]
  1328. Tell whether the garbage collector (GC) must keep outputs of live
  1329. derivations.
  1330. @cindex GC roots
  1331. @cindex garbage collector roots
  1332. When set to @code{yes}, the GC will keep the outputs of any live
  1333. derivation available in the store---the @file{.drv} files. The default
  1334. is @code{no}, meaning that derivation outputs are kept only if they are
  1335. reachable from a GC root. @xref{Invoking guix gc}, for more on GC
  1336. roots.
  1337. @item --gc-keep-derivations[=yes|no]
  1338. Tell whether the garbage collector (GC) must keep derivations
  1339. corresponding to live outputs.
  1340. When set to @code{yes}, as is the case by default, the GC keeps
  1341. derivations---i.e., @file{.drv} files---as long as at least one of their
  1342. outputs is live. This allows users to keep track of the origins of
  1343. items in their store. Setting it to @code{no} saves a bit of disk
  1344. space.
  1345. In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
  1346. liveness to flow from outputs to derivations, and setting
  1347. @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
  1348. derivations to outputs. When both are set to @code{yes}, the effect is
  1349. to keep all the build prerequisites (the sources, compiler, libraries,
  1350. and other build-time tools) of live objects in the store, regardless of
  1351. whether these prerequisites are reachable from a GC root. This is
  1352. convenient for developers since it saves rebuilds or downloads.
  1353. @item --impersonate-linux-2.6
  1354. On Linux-based systems, impersonate Linux 2.6. This means that the
  1355. kernel's @command{uname} system call will report 2.6 as the release number.
  1356. This might be helpful to build programs that (usually wrongfully) depend
  1357. on the kernel version number.
  1358. @item --lose-logs
  1359. Do not keep build logs. By default they are kept under
  1360. @file{@var{localstatedir}/guix/log}.
  1361. @item --system=@var{system}
  1362. Assume @var{system} as the current system type. By default it is the
  1363. architecture/kernel pair found at configure time, such as
  1364. @code{x86_64-linux}.
  1365. @item --listen=@var{endpoint}
  1366. Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
  1367. as the file name of a Unix-domain socket if it starts with
  1368. @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
  1369. host name or host name and port to listen to. Here are a few examples:
  1370. @table @code
  1371. @item --listen=/gnu/var/daemon
  1372. Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
  1373. creating it if needed.
  1374. @item --listen=localhost
  1375. @cindex daemon, remote access
  1376. @cindex remote access to the daemon
  1377. @cindex daemon, cluster setup
  1378. @cindex clusters, daemon setup
  1379. Listen for TCP connections on the network interface corresponding to
  1380. @code{localhost}, on port 44146.
  1381. @item --listen=128.0.0.42:1234
  1382. Listen for TCP connections on the network interface corresponding to
  1383. @code{128.0.0.42}, on port 1234.
  1384. @end table
  1385. This option can be repeated multiple times, in which case
  1386. @command{guix-daemon} accepts connections on all the specified
  1387. endpoints. Users can tell client commands what endpoint to connect to
  1388. by setting the @env{GUIX_DAEMON_SOCKET} environment variable
  1389. (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
  1390. @quotation Note
  1391. The daemon protocol is @emph{unauthenticated and unencrypted}. Using
  1392. @option{--listen=@var{host}} is suitable on local networks, such as
  1393. clusters, where only trusted nodes may connect to the build daemon. In
  1394. other cases where remote access to the daemon is needed, we recommend
  1395. using Unix-domain sockets along with SSH.
  1396. @end quotation
  1397. When @option{--listen} is omitted, @command{guix-daemon} listens for
  1398. connections on the Unix-domain socket located at
  1399. @file{@var{localstatedir}/guix/daemon-socket/socket}.
  1400. @end table
  1401. @node Application Setup
  1402. @section Application Setup
  1403. @cindex foreign distro
  1404. When using Guix on top of GNU/Linux distribution other than Guix System---a
  1405. so-called @dfn{foreign distro}---a few additional steps are needed to
  1406. get everything in place. Here are some of them.
  1407. @subsection Locales
  1408. @anchor{locales-and-locpath}
  1409. @cindex locales, when not on Guix System
  1410. @vindex LOCPATH
  1411. @vindex GUIX_LOCPATH
  1412. Packages installed @i{via} Guix will not use the locale data of the
  1413. host system. Instead, you must first install one of the locale packages
  1414. available with Guix and then define the @env{GUIX_LOCPATH} environment
  1415. variable:
  1416. @example
  1417. $ guix install glibc-locales
  1418. $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
  1419. @end example
  1420. Note that the @code{glibc-locales} package contains data for all the
  1421. locales supported by the GNU@tie{}libc and weighs in at around
  1422. 917@tie{}MiB@. Alternatively, the @code{glibc-utf8-locales} is smaller but
  1423. limited to a few UTF-8 locales.
  1424. The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
  1425. (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
  1426. Manual}). There are two important differences though:
  1427. @enumerate
  1428. @item
  1429. @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
  1430. provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
  1431. to make sure the programs of the foreign distro will not end up loading
  1432. incompatible locale data.
  1433. @item
  1434. libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
  1435. @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
  1436. should your Guix profile contain a mixture of programs linked against
  1437. different libc version, each libc version will only try to load locale
  1438. data in the right format.
  1439. @end enumerate
  1440. This is important because the locale data format used by different libc
  1441. versions may be incompatible.
  1442. @subsection Name Service Switch
  1443. @cindex name service switch, glibc
  1444. @cindex NSS (name service switch), glibc
  1445. @cindex nscd (name service caching daemon)
  1446. @cindex name service caching daemon (nscd)
  1447. When using Guix on a foreign distro, we @emph{strongly recommend} that
  1448. the system run the GNU C library's @dfn{name service cache daemon},
  1449. @command{nscd}, which should be listening on the
  1450. @file{/var/run/nscd/socket} socket. Failing to do that, applications
  1451. installed with Guix may fail to look up host names or user accounts, or
  1452. may even crash. The next paragraphs explain why.
  1453. @cindex @file{nsswitch.conf}
  1454. The GNU C library implements a @dfn{name service switch} (NSS), which is
  1455. an extensible mechanism for ``name lookups'' in general: host name
  1456. resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
  1457. The GNU C Library Reference Manual}).
  1458. @cindex Network information service (NIS)
  1459. @cindex NIS (Network information service)
  1460. Being extensible, the NSS supports @dfn{plugins}, which provide new name
  1461. lookup implementations: for example, the @code{nss-mdns} plugin allow
  1462. resolution of @code{.local} host names, the @code{nis} plugin allows
  1463. user account lookup using the Network information service (NIS), and so
  1464. on. These extra ``lookup services'' are configured system-wide in
  1465. @file{/etc/nsswitch.conf}, and all the programs running on the system
  1466. honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
  1467. Reference Manual}).
  1468. When they perform a name lookup---for instance by calling the
  1469. @code{getaddrinfo} function in C---applications first try to connect to
  1470. the nscd; on success, nscd performs name lookups on their behalf. If
  1471. the nscd is not running, then they perform the name lookup by
  1472. themselves, by loading the name lookup services into their own address
  1473. space and running it. These name lookup services---the
  1474. @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
  1475. the host system's C library, rather than from the C library the
  1476. application is linked against (the C library coming from Guix).
  1477. And this is where the problem is: if your application is linked against
  1478. Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
  1479. another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
  1480. likely crash or have its name lookups fail unexpectedly.
  1481. Running @command{nscd} on the system, among other advantages, eliminates
  1482. this binary incompatibility problem because those @code{libnss_*.so}
  1483. files are loaded in the @command{nscd} process, not in applications
  1484. themselves.
  1485. @subsection X11 Fonts
  1486. @cindex fonts
  1487. The majority of graphical applications use Fontconfig to locate and
  1488. load fonts and perform X11-client-side rendering. The @code{fontconfig}
  1489. package in Guix looks for fonts in @file{$HOME/.guix-profile}
  1490. by default. Thus, to allow graphical applications installed with Guix
  1491. to display fonts, you have to install fonts with Guix as well.
  1492. Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
  1493. @code{font-gnu-freefont}.
  1494. @cindex @code{fc-cache}
  1495. @cindex font cache
  1496. Once you have installed or removed fonts, or when you notice an
  1497. application that does not find fonts, you may need to install Fontconfig
  1498. and to force an update of its font cache by running:
  1499. @example
  1500. guix install fontconfig
  1501. fc-cache -rv
  1502. @end example
  1503. To display text written in Chinese languages, Japanese, or Korean in
  1504. graphical applications, consider installing
  1505. @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
  1506. has multiple outputs, one per language family (@pxref{Packages with
  1507. Multiple Outputs}). For instance, the following command installs fonts
  1508. for Chinese languages:
  1509. @example
  1510. guix install font-adobe-source-han-sans:cn
  1511. @end example
  1512. @cindex @code{xterm}
  1513. Older programs such as @command{xterm} do not use Fontconfig and instead
  1514. rely on server-side font rendering. Such programs require to specify a
  1515. full name of a font using XLFD (X Logical Font Description), like this:
  1516. @example
  1517. -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
  1518. @end example
  1519. To be able to use such full names for the TrueType fonts installed in
  1520. your Guix profile, you need to extend the font path of the X server:
  1521. @c Note: 'xset' does not accept symlinks so the trick below arranges to
  1522. @c get at the real directory. See <https://bugs.gnu.org/30655>.
  1523. @example
  1524. xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
  1525. @end example
  1526. @cindex @code{xlsfonts}
  1527. After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
  1528. to make sure your TrueType fonts are listed there.
  1529. @subsection X.509 Certificates
  1530. @cindex @code{nss-certs}
  1531. The @code{nss-certs} package provides X.509 certificates, which allow
  1532. programs to authenticate Web servers accessed over HTTPS.
  1533. When using Guix on a foreign distro, you can install this package and
  1534. define the relevant environment variables so that packages know where to
  1535. look for certificates. @xref{X.509 Certificates}, for detailed
  1536. information.
  1537. @subsection Emacs Packages
  1538. @cindex @code{emacs}
  1539. When you install Emacs packages with Guix, the Elisp files are placed
  1540. under the @file{share/emacs/site-lisp/} directory of the profile in
  1541. which they are installed. The Elisp libraries are made available to
  1542. Emacs through the @env{EMACSLOADPATH} environment variable, which is
  1543. set when installing Emacs itself.
  1544. Additionally, autoload definitions are automatically evaluated at the
  1545. initialization of Emacs, by the Guix-specific
  1546. @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
  1547. want to avoid auto-loading the Emacs packages installed with Guix, you
  1548. can do so by running Emacs with the @option{--no-site-file} option
  1549. (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
  1550. @node Upgrading Guix
  1551. @section Upgrading Guix
  1552. @cindex Upgrading Guix, on a foreign distro
  1553. To upgrade Guix, run:
  1554. @example
  1555. guix pull
  1556. @end example
  1557. @xref{Invoking guix pull}, for more information.
  1558. @cindex upgrading Guix for the root user, on a foreign distro
  1559. @cindex upgrading the Guix daemon, on a foreign distro
  1560. @cindex @command{guix pull} for the root user, on a foreign distro
  1561. On a foreign distro, you can upgrade the build daemon by running:
  1562. @example
  1563. sudo -i guix pull
  1564. @end example
  1565. @noindent
  1566. followed by (assuming your distro uses the systemd service management
  1567. tool):
  1568. @example
  1569. systemctl restart guix-daemon.service
  1570. @end example
  1571. On Guix System, upgrading the daemon is achieved by reconfiguring the
  1572. system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
  1573. @c TODO What else?
  1574. @c *********************************************************************
  1575. @node System Installation
  1576. @chapter System Installation
  1577. @cindex installing Guix System
  1578. @cindex Guix System, installation
  1579. This section explains how to install Guix System
  1580. on a machine. Guix, as a package manager, can
  1581. also be installed on top of a running GNU/Linux system,
  1582. @pxref{Installation}.
  1583. @ifinfo
  1584. @quotation Note
  1585. @c This paragraph is for people reading this from tty2 of the
  1586. @c installation image.
  1587. You are reading this documentation with an Info reader. For details on
  1588. how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
  1589. link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
  1590. Info}. Hit @kbd{l} afterwards to come back here.
  1591. Alternatively, run @command{info info} in another tty to keep the manual
  1592. available.
  1593. @end quotation
  1594. @end ifinfo
  1595. @menu
  1596. * Limitations:: What you can expect.
  1597. * Hardware Considerations:: Supported hardware.
  1598. * USB Stick and DVD Installation:: Preparing the installation medium.
  1599. * Preparing for Installation:: Networking, partitioning, etc.
  1600. * Guided Graphical Installation:: Easy graphical installation.
  1601. * Manual Installation:: Manual installation for wizards.
  1602. * After System Installation:: When installation succeeded.
  1603. * Installing Guix in a VM:: Guix System playground.
  1604. * Building the Installation Image:: How this comes to be.
  1605. @end menu
  1606. @node Limitations
  1607. @section Limitations
  1608. We consider Guix System to be ready for a wide range of ``desktop'' and server
  1609. use cases. The reliability guarantees it provides---transactional upgrades
  1610. and rollbacks, reproducibility---make it a solid foundation.
  1611. Nevertheless, before you proceed with the installation, be aware of the
  1612. following noteworthy limitations applicable to version @value{VERSION}:
  1613. @itemize
  1614. @item
  1615. More and more system services are provided (@pxref{Services}), but some
  1616. may be missing.
  1617. @item
  1618. GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
  1619. as well as a number of X11 window managers. However, KDE is currently
  1620. missing.
  1621. @end itemize
  1622. More than a disclaimer, this is an invitation to report issues (and success
  1623. stories!), and to join us in improving it. @xref{Contributing}, for more
  1624. info.
  1625. @node Hardware Considerations
  1626. @section Hardware Considerations
  1627. @cindex hardware support on Guix System
  1628. GNU@tie{}Guix focuses on respecting the user's computing freedom. It
  1629. builds around the kernel Linux-libre, which means that only hardware for
  1630. which free software drivers and firmware exist is supported. Nowadays,
  1631. a wide range of off-the-shelf hardware is supported on
  1632. GNU/Linux-libre---from keyboards to graphics cards to scanners and
  1633. Ethernet controllers. Unfortunately, there are still areas where
  1634. hardware vendors deny users control over their own computing, and such
  1635. hardware is not supported on Guix System.
  1636. @cindex WiFi, hardware support
  1637. One of the main areas where free drivers or firmware are lacking is WiFi
  1638. devices. WiFi devices known to work include those using Atheros chips
  1639. (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
  1640. driver, and those using Broadcom/AirForce chips (BCM43xx with
  1641. Wireless-Core Revision 5), which corresponds to the @code{b43-open}
  1642. Linux-libre driver. Free firmware exists for both and is available
  1643. out-of-the-box on Guix System, as part of @code{%base-firmware}
  1644. (@pxref{operating-system Reference, @code{firmware}}).
  1645. @cindex RYF, Respects Your Freedom
  1646. The @uref{https://www.fsf.org/, Free Software Foundation} runs
  1647. @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
  1648. certification program for hardware products that respect your freedom
  1649. and your privacy and ensure that you have control over your device. We
  1650. encourage you to check the list of RYF-certified devices.
  1651. Another useful resource is the @uref{https://www.h-node.org/, H-Node}
  1652. web site. It contains a catalog of hardware devices with information
  1653. about their support in GNU/Linux.
  1654. @node USB Stick and DVD Installation
  1655. @section USB Stick and DVD Installation
  1656. An ISO-9660 installation image that can be written to a USB stick or
  1657. burnt to a DVD can be downloaded from
  1658. @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
  1659. where you can replace @code{x86_64-linux} with one of:
  1660. @table @code
  1661. @item x86_64-linux
  1662. for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
  1663. @item i686-linux
  1664. for a 32-bit GNU/Linux system on Intel-compatible CPUs.
  1665. @end table
  1666. @c start duplication of authentication part from ``Binary Installation''
  1667. Make sure to download the associated @file{.sig} file and to verify the
  1668. authenticity of the image against it, along these lines:
  1669. @example
  1670. $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
  1671. $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
  1672. @end example
  1673. If that command fails because you do not have the required public key,
  1674. then run this command to import it:
  1675. @example
  1676. $ wget @value{OPENPGP-SIGNING-KEY-URL} \
  1677. -qO - | gpg --import -
  1678. @end example
  1679. @noindent
  1680. and rerun the @code{gpg --verify} command.
  1681. Take note that a warning like ``This key is not certified with a trusted
  1682. signature!'' is normal.
  1683. @c end duplication
  1684. This image contains the tools necessary for an installation.
  1685. It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
  1686. @unnumberedsubsec Copying to a USB Stick
  1687. To copy the image to a USB stick, follow these steps:
  1688. @enumerate
  1689. @item
  1690. Decompress the image using the @command{xz} command:
  1691. @example
  1692. xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
  1693. @end example
  1694. @item
  1695. Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
  1696. its device name. Assuming that the USB stick is known as @file{/dev/sdX},
  1697. copy the image with:
  1698. @example
  1699. dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
  1700. sync
  1701. @end example
  1702. Access to @file{/dev/sdX} usually requires root privileges.
  1703. @end enumerate
  1704. @unnumberedsubsec Burning on a DVD
  1705. To copy the image to a DVD, follow these steps:
  1706. @enumerate
  1707. @item
  1708. Decompress the image using the @command{xz} command:
  1709. @example
  1710. xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
  1711. @end example
  1712. @item
  1713. Insert a blank DVD into your machine, and determine
  1714. its device name. Assuming that the DVD drive is known as @file{/dev/srX},
  1715. copy the image with:
  1716. @example
  1717. growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
  1718. @end example
  1719. Access to @file{/dev/srX} usually requires root privileges.
  1720. @end enumerate
  1721. @unnumberedsubsec Booting
  1722. Once this is done, you should be able to reboot the system and boot from
  1723. the USB stick or DVD@. The latter usually requires you to get in the
  1724. BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
  1725. In order to boot from Libreboot, switch to the command mode by pressing
  1726. the @kbd{c} key and type @command{search_grub usb}.
  1727. @xref{Installing Guix in a VM}, if, instead, you would like to install
  1728. Guix System in a virtual machine (VM).
  1729. @node Preparing for Installation
  1730. @section Preparing for Installation
  1731. Once you have booted, you can use the guided graphical installer, which makes
  1732. it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
  1733. if you are already familiar with GNU/Linux and if you want more control than
  1734. what the graphical installer provides, you can choose the ``manual''
  1735. installation process (@pxref{Manual Installation}).
  1736. The graphical installer is available on TTY1. You can obtain root shells on
  1737. TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
  1738. this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
  1739. is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
  1740. Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
  1741. which allows you to select text with the left mouse button and to paste it
  1742. with the middle button.
  1743. @quotation Note
  1744. Installation requires access to the Internet so that any missing
  1745. dependencies of your system configuration can be downloaded. See the
  1746. ``Networking'' section below.
  1747. @end quotation
  1748. @node Guided Graphical Installation
  1749. @section Guided Graphical Installation
  1750. The graphical installer is a text-based user interface. It will guide you,
  1751. with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
  1752. The first dialog boxes allow you to set up the system as you use it during the
  1753. installation: you can choose the language, keyboard layout, and set up
  1754. networking, which will be used during the installation. The image below shows
  1755. the networking dialog.
  1756. @image{images/installer-network,5in,, networking setup with the graphical installer}
  1757. Later steps allow you to partition your hard disk, as shown in the image
  1758. below, to choose whether or not to use encrypted file systems, to enter the
  1759. host name and root password, and to create an additional account, among other
  1760. things.
  1761. @image{images/installer-partitions,5in,, partitioning with the graphical installer}
  1762. Note that, at any time, the installer allows you to exit the current
  1763. installation step and resume at a previous step, as show in the image below.
  1764. @image{images/installer-resume,5in,, resuming the installation process}
  1765. Once you're done, the installer produces an operating system configuration and
  1766. displays it (@pxref{Using the Configuration System}). At that point you can
  1767. hit ``OK'' and installation will proceed. On success, you can reboot into the
  1768. new system and enjoy. @xref{After System Installation}, for what's next!
  1769. @node Manual Installation
  1770. @section Manual Installation
  1771. This section describes how you would ``manually'' install GNU@tie{}Guix System
  1772. on your machine. This option requires familiarity with GNU/Linux, with the
  1773. shell, and with common administration tools. If you think this is not for
  1774. you, consider using the guided graphical installer (@pxref{Guided Graphical
  1775. Installation}).
  1776. The installation system provides root shells on TTYs 3 to 6; press
  1777. @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
  1778. many common tools needed to install the system. But it is also a full-blown
  1779. Guix System, which means that you can install additional packages, should you
  1780. need it, using @command{guix package} (@pxref{Invoking guix package}).
  1781. @menu
  1782. * Keyboard Layout and Networking and Partitioning:: Initial setup.
  1783. * Proceeding with the Installation:: Installing.
  1784. @end menu
  1785. @node Keyboard Layout and Networking and Partitioning
  1786. @subsection Keyboard Layout, Networking, and Partitioning
  1787. Before you can install the system, you may want to adjust the keyboard layout,
  1788. set up networking, and partition your target hard disk. This section will
  1789. guide you through this.
  1790. @subsubsection Keyboard Layout
  1791. @cindex keyboard layout
  1792. The installation image uses the US qwerty keyboard layout. If you want
  1793. to change it, you can use the @command{loadkeys} command. For example,
  1794. the following command selects the Dvorak keyboard layout:
  1795. @example
  1796. loadkeys dvorak
  1797. @end example
  1798. See the files under @file{/run/current-system/profile/share/keymaps} for
  1799. a list of available keyboard layouts. Run @command{man loadkeys} for
  1800. more information.
  1801. @subsubsection Networking
  1802. Run the following command to see what your network interfaces are called:
  1803. @example
  1804. ifconfig -a
  1805. @end example
  1806. @noindent
  1807. @dots{} or, using the GNU/Linux-specific @command{ip} command:
  1808. @example
  1809. ip address
  1810. @end example
  1811. @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
  1812. Wired interfaces have a name starting with @samp{e}; for example, the
  1813. interface corresponding to the first on-board Ethernet controller is
  1814. called @samp{eno1}. Wireless interfaces have a name starting with
  1815. @samp{w}, like @samp{w1p2s0}.
  1816. @table @asis
  1817. @item Wired connection
  1818. To configure a wired network run the following command, substituting
  1819. @var{interface} with the name of the wired interface you want to use.
  1820. @example
  1821. ifconfig @var{interface} up
  1822. @end example
  1823. @noindent
  1824. @dots{} or, using the GNU/Linux-specific @command{ip} command:
  1825. @example
  1826. ip link set @var{interface} up
  1827. @end example
  1828. @item Wireless connection
  1829. @cindex wireless
  1830. @cindex WiFi
  1831. To configure wireless networking, you can create a configuration file
  1832. for the @command{wpa_supplicant} configuration tool (its location is not
  1833. important) using one of the available text editors such as
  1834. @command{nano}:
  1835. @example
  1836. nano wpa_supplicant.conf
  1837. @end example
  1838. As an example, the following stanza can go to this file and will work
  1839. for many wireless networks, provided you give the actual SSID and
  1840. passphrase for the network you are connecting to:
  1841. @example
  1842. network=@{
  1843. ssid="@var{my-ssid}"
  1844. key_mgmt=WPA-PSK
  1845. psk="the network's secret passphrase"
  1846. @}
  1847. @end example
  1848. Start the wireless service and run it in the background with the
  1849. following command (substitute @var{interface} with the name of the
  1850. network interface you want to use):
  1851. @example
  1852. wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
  1853. @end example
  1854. Run @command{man wpa_supplicant} for more information.
  1855. @end table
  1856. @cindex DHCP
  1857. At this point, you need to acquire an IP address. On a network where IP
  1858. addresses are automatically assigned @i{via} DHCP, you can run:
  1859. @example
  1860. dhclient -v @var{interface}
  1861. @end example
  1862. Try to ping a server to see if networking is up and running:
  1863. @example
  1864. ping -c 3 gnu.org
  1865. @end example
  1866. Setting up network access is almost always a requirement because the
  1867. image does not contain all the software and tools that may be needed.
  1868. @cindex proxy, during system installation
  1869. If you need HTTP and HTTPS access to go through a proxy, run the
  1870. following command:
  1871. @example
  1872. herd set-http-proxy guix-daemon @var{URL}
  1873. @end example
  1874. @noindent
  1875. where @var{URL} is the proxy URL, for example
  1876. @code{http://example.org:8118}.
  1877. @cindex installing over SSH
  1878. If you want to, you can continue the installation remotely by starting
  1879. an SSH server:
  1880. @example
  1881. herd start ssh-daemon
  1882. @end example
  1883. Make sure to either set a password with @command{passwd}, or configure
  1884. OpenSSH public key authentication before logging in.
  1885. @subsubsection Disk Partitioning
  1886. Unless this has already been done, the next step is to partition, and
  1887. then format the target partition(s).
  1888. The installation image includes several partitioning tools, including
  1889. Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
  1890. @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
  1891. the partition layout you want:
  1892. @example
  1893. cfdisk
  1894. @end example
  1895. If your disk uses the GUID Partition Table (GPT) format and you plan to
  1896. install BIOS-based GRUB (which is the default), make sure a BIOS Boot
  1897. Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
  1898. manual}).
  1899. @cindex EFI, installation
  1900. @cindex UEFI, installation
  1901. @cindex ESP, EFI system partition
  1902. If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
  1903. (ESP) is required. This partition can be mounted at @file{/boot/efi} for
  1904. instance and must have the @code{esp} flag set. E.g., for @command{parted}:
  1905. @example
  1906. parted /dev/sda set 1 esp on
  1907. @end example
  1908. @quotation Note
  1909. @vindex grub-bootloader
  1910. @vindex grub-efi-bootloader
  1911. Unsure whether to use EFI- or BIOS-based GRUB? If the directory
  1912. @file{/sys/firmware/efi} exists in the installation image, then you should
  1913. probably perform an EFI installation, using @code{grub-efi-bootloader}.
  1914. Otherwise you should use the BIOS-based GRUB, known as
  1915. @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
  1916. bootloaders.
  1917. @end quotation
  1918. Once you are done partitioning the target hard disk drive, you have to
  1919. create a file system on the relevant partition(s)@footnote{Currently
  1920. Guix System only supports ext4, btrfs, JFS, and F2FS file systems. In
  1921. particular, code that reads file system UUIDs and labels only works for these
  1922. file system types.}. For the ESP, if you have one and assuming it is
  1923. @file{/dev/sda1}, run:
  1924. @example
  1925. mkfs.fat -F32 /dev/sda1
  1926. @end example
  1927. For the root file system, ext4 is the most widely used format. Other
  1928. file systems, such as Btrfs, support compression, which is reported to
  1929. nicely complement file deduplication that the daemon performs
  1930. independently of the file system (@pxref{Invoking guix-daemon,
  1931. deduplication}).
  1932. Preferably, assign file systems a label so that you can easily and
  1933. reliably refer to them in @code{file-system} declarations (@pxref{File
  1934. Systems}). This is typically done using the @code{-L} option of
  1935. @command{mkfs.ext4} and related commands. So, assuming the target root
  1936. partition lives at @file{/dev/sda2}, a file system with the label
  1937. @code{my-root} can be created with:
  1938. @example
  1939. mkfs.ext4 -L my-root /dev/sda2
  1940. @end example
  1941. @cindex encrypted disk
  1942. If you are instead planning to encrypt the root partition, you can use
  1943. the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
  1944. @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
  1945. @code{man cryptsetup}} for more information). Assuming you want to
  1946. store the root partition on @file{/dev/sda2}, the command sequence would
  1947. be along these lines:
  1948. @example
  1949. cryptsetup luksFormat /dev/sda2
  1950. cryptsetup open --type luks /dev/sda2 my-partition
  1951. mkfs.ext4 -L my-root /dev/mapper/my-partition
  1952. @end example
  1953. Once that is done, mount the target file system under @file{/mnt}
  1954. with a command like (again, assuming @code{my-root} is the label of the
  1955. root file system):
  1956. @example
  1957. mount LABEL=my-root /mnt
  1958. @end example
  1959. Also mount any other file systems you would like to use on the target
  1960. system relative to this path. If you have opted for @file{/boot/efi} as an
  1961. EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
  1962. found by @code{guix system init} afterwards.
  1963. Finally, if you plan to use one or more swap partitions (@pxref{Memory
  1964. Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
  1965. sure to initialize them with @command{mkswap}. Assuming you have one
  1966. swap partition on @file{/dev/sda3}, you would run:
  1967. @example
  1968. mkswap /dev/sda3
  1969. swapon /dev/sda3
  1970. @end example
  1971. Alternatively, you may use a swap file. For example, assuming that in
  1972. the new system you want to use the file @file{/swapfile} as a swap file,
  1973. you would run@footnote{This example will work for many types of file
  1974. systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
  1975. btrfs), the required steps may be different. For details, see the
  1976. manual pages for @command{mkswap} and @command{swapon}.}:
  1977. @example
  1978. # This is 10 GiB of swap space. Adjust "count" to change the size.
  1979. dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
  1980. # For security, make the file readable and writable only by root.
  1981. chmod 600 /mnt/swapfile
  1982. mkswap /mnt/swapfile
  1983. swapon /mnt/swapfile
  1984. @end example
  1985. Note that if you have encrypted the root partition and created a swap
  1986. file in its file system as described above, then the encryption also
  1987. protects the swap file, just like any other file in that file system.
  1988. @node Proceeding with the Installation
  1989. @subsection Proceeding with the Installation
  1990. With the target partitions ready and the target root mounted on
  1991. @file{/mnt}, we're ready to go. First, run:
  1992. @example
  1993. herd start cow-store /mnt
  1994. @end example
  1995. This makes @file{/gnu/store} copy-on-write, such that packages added to it
  1996. during the installation phase are written to the target disk on @file{/mnt}
  1997. rather than kept in memory. This is necessary because the first phase of
  1998. the @command{guix system init} command (see below) entails downloads or
  1999. builds to @file{/gnu/store} which, initially, is an in-memory file system.
  2000. Next, you have to edit a file and
  2001. provide the declaration of the operating system to be installed. To
  2002. that end, the installation system comes with three text editors. We
  2003. recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
  2004. supports syntax highlighting and parentheses matching; other editors
  2005. include GNU Zile (an Emacs clone), and
  2006. nvi (a clone of the original BSD @command{vi} editor).
  2007. We strongly recommend storing that file on the target root file system, say,
  2008. as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
  2009. configuration file once you have rebooted into the newly-installed system.
  2010. @xref{Using the Configuration System}, for an overview of the
  2011. configuration file. The example configurations discussed in that
  2012. section are available under @file{/etc/configuration} in the
  2013. installation image. Thus, to get started with a system configuration
  2014. providing a graphical display server (a ``desktop'' system), you can run
  2015. something along these lines:
  2016. @example
  2017. # mkdir /mnt/etc
  2018. # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
  2019. # nano /mnt/etc/config.scm
  2020. @end example
  2021. You should pay attention to what your configuration file contains, and
  2022. in particular:
  2023. @itemize
  2024. @item
  2025. Make sure the @code{bootloader-configuration} form refers to the target
  2026. you want to install GRUB on. It should mention @code{grub-bootloader} if
  2027. you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
  2028. for newer UEFI systems. For legacy systems, the @code{target} field
  2029. names a device, like @code{/dev/sda}; for UEFI systems it names a path
  2030. to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
  2031. currently mounted and a @code{file-system} entry is specified in your
  2032. configuration.
  2033. @item
  2034. Be sure that your file system labels match the value of their respective
  2035. @code{device} fields in your @code{file-system} configuration, assuming
  2036. your @code{file-system} configuration uses the @code{file-system-label}
  2037. procedure in its @code{device} field.
  2038. @item
  2039. If there are encrypted or RAID partitions, make sure to add a
  2040. @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
  2041. @end itemize
  2042. Once you are done preparing the configuration file, the new system must
  2043. be initialized (remember that the target root file system is mounted
  2044. under @file{/mnt}):
  2045. @example
  2046. guix system init /mnt/etc/config.scm /mnt
  2047. @end example
  2048. @noindent
  2049. This copies all the necessary files and installs GRUB on
  2050. @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
  2051. more information, @pxref{Invoking guix system}. This command may trigger
  2052. downloads or builds of missing packages, which can take some time.
  2053. Once that command has completed---and hopefully succeeded!---you can run
  2054. @command{reboot} and boot into the new system. The @code{root} password
  2055. in the new system is initially empty; other users' passwords need to be
  2056. initialized by running the @command{passwd} command as @code{root},
  2057. unless your configuration specifies otherwise
  2058. (@pxref{user-account-password, user account passwords}).
  2059. @xref{After System Installation}, for what's next!
  2060. @node After System Installation
  2061. @section After System Installation
  2062. Success, you've now booted into Guix System! From then on, you can update the
  2063. system whenever you want by running, say:
  2064. @example
  2065. guix pull
  2066. sudo guix system reconfigure /etc/config.scm
  2067. @end example
  2068. @noindent
  2069. This builds a new system generation with the latest packages and services
  2070. (@pxref{Invoking guix system}). We recommend doing that regularly so that
  2071. your system includes the latest security updates (@pxref{Security Updates}).
  2072. @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
  2073. @quotation Note
  2074. @cindex sudo vs. @command{guix pull}
  2075. Note that @command{sudo guix} runs your user's @command{guix} command and
  2076. @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
  2077. explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
  2078. The difference matters here, because @command{guix pull} updates
  2079. the @command{guix} command and package definitions only for the user it is ran
  2080. as. This means that if you choose to use @command{guix system reconfigure} in
  2081. root's login shell, you'll need to @command{guix pull} separately.
  2082. @end quotation
  2083. Now, @pxref{Getting Started}, and
  2084. join us on @code{#guix} on the Freenode IRC network or on
  2085. @email{guix-devel@@gnu.org} to share your experience!
  2086. @node Installing Guix in a VM
  2087. @section Installing Guix in a Virtual Machine
  2088. @cindex virtual machine, Guix System installation
  2089. @cindex virtual private server (VPS)
  2090. @cindex VPS (virtual private server)
  2091. If you'd like to install Guix System in a virtual machine (VM) or on a
  2092. virtual private server (VPS) rather than on your beloved machine, this
  2093. section is for you.
  2094. To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
  2095. disk image, follow these steps:
  2096. @enumerate
  2097. @item
  2098. First, retrieve and decompress the Guix system installation image as
  2099. described previously (@pxref{USB Stick and DVD Installation}).
  2100. @item
  2101. Create a disk image that will hold the installed system. To make a
  2102. qcow2-formatted disk image, use the @command{qemu-img} command:
  2103. @example
  2104. qemu-img create -f qcow2 guix-system.img 50G
  2105. @end example
  2106. The resulting file will be much smaller than 50 GB (typically less than
  2107. 1 MB), but it will grow as the virtualized storage device is filled up.
  2108. @item
  2109. Boot the USB installation image in an VM:
  2110. @example
  2111. qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
  2112. -nic user,model=virtio-net-pci -boot menu=on,order=d \
  2113. -drive file=guix-system.img \
  2114. -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
  2115. @end example
  2116. @code{-enable-kvm} is optional, but significantly improves performance,
  2117. @pxref{Running Guix in a VM}.
  2118. @item
  2119. You're now root in the VM, proceed with the installation process.
  2120. @xref{Preparing for Installation}, and follow the instructions.
  2121. @end enumerate
  2122. Once installation is complete, you can boot the system that's on your
  2123. @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
  2124. that.
  2125. @node Building the Installation Image
  2126. @section Building the Installation Image
  2127. @cindex installation image
  2128. The installation image described above was built using the @command{guix
  2129. system} command, specifically:
  2130. @example
  2131. guix system image -t iso9660 gnu/system/install.scm
  2132. @end example
  2133. Have a look at @file{gnu/system/install.scm} in the source tree,
  2134. and see also @ref{Invoking guix system} for more information
  2135. about the installation image.
  2136. @section Building the Installation Image for ARM Boards
  2137. Many ARM boards require a specific variant of the
  2138. @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
  2139. If you build a disk image and the bootloader is not available otherwise
  2140. (on another boot drive etc), it's advisable to build an image that
  2141. includes the bootloader, specifically:
  2142. @example
  2143. guix system image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
  2144. @end example
  2145. @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
  2146. board, a list of possible boards will be printed.
  2147. @c *********************************************************************
  2148. @node Getting Started
  2149. @chapter Getting Started
  2150. Presumably, you've reached this section because either you have
  2151. installed Guix on top of another distribution (@pxref{Installation}), or
  2152. you've installed the standalone Guix System (@pxref{System
  2153. Installation}). It's time for you to get started using Guix and this
  2154. section aims to help you do that and give you a feel of what it's like.
  2155. Guix is about installing software, so probably the first thing you'll
  2156. want to do is to actually look for software. Let's say you're looking
  2157. for a text editor, you can run:
  2158. @example
  2159. guix search text editor
  2160. @end example
  2161. This command shows you a number of matching @dfn{packages}, each time
  2162. showing the package's name, version, a description, and additional info.
  2163. Once you've found out the one you want to use, let's say Emacs (ah ha!),
  2164. you can go ahead and install it (run this command as a regular user,
  2165. @emph{no need for root privileges}!):
  2166. @example
  2167. guix install emacs
  2168. @end example
  2169. You've installed your first package, congrats! In the process, you've
  2170. probably noticed that Guix downloaded pre-built binaries; or, if you
  2171. explicitly chose to @emph{not} use pre-built binaries, then probably
  2172. Guix is still building software (@pxref{Substitutes}, for more info).
  2173. Unless you're using Guix System, the @command{guix install} command must
  2174. have printed this hint:
  2175. @example
  2176. hint: Consider setting the necessary environment variables by running:
  2177. GUIX_PROFILE="$HOME/.guix-profile"
  2178. . "$GUIX_PROFILE/etc/profile"
  2179. Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
  2180. @end example
  2181. Indeed, you must now tell your shell where @command{emacs} and other
  2182. programs installed with Guix are to be found. Pasting the two lines
  2183. above will do just that: it will add
  2184. @code{$HOME/.guix-profile/bin}---which is where the installed package
  2185. is---to the @code{PATH} environment variable. You can paste these two
  2186. lines in your shell so they take effect right away, but more importantly
  2187. you should add them to @file{~/.bash_profile} (or equivalent file if you
  2188. do not use Bash) so that environment variables are set next time you
  2189. spawn a shell. You only need to do this once and other search paths
  2190. environment variables will be taken care of similarly---e.g., if you
  2191. eventually install @code{python} and Python libraries, @code{PYTHONPATH}
  2192. will be defined.
  2193. You can go on installing packages at your will. To list installed
  2194. packages, run:
  2195. @example
  2196. guix package --list-installed
  2197. @end example
  2198. To remove a package, you would unsurprisingly run @command{guix remove}.
  2199. A distinguishing feature is the ability to @dfn{roll back} any operation
  2200. you made---installation, removal, upgrade---by simply typing:
  2201. @example
  2202. guix package --roll-back
  2203. @end example
  2204. This is because each operation is in fact a @dfn{transaction} that
  2205. creates a new @dfn{generation}. These generations and the difference
  2206. between them can be displayed by running:
  2207. @example
  2208. guix package --list-generations
  2209. @end example
  2210. Now you know the basics of package management!
  2211. @quotation Going further
  2212. @xref{Package Management}, for more about package management. You may
  2213. like @dfn{declarative} package management with @command{guix package
  2214. --manifest}, managing separate @dfn{profiles} with @option{--profile},
  2215. deleting old generations, collecting garbage, and other nifty features
  2216. that will come in handy as you become more familiar with Guix. If you
  2217. are a developer, @pxref{Development} for additional tools. And if
  2218. you're curious, @pxref{Features}, to peek under the hood.
  2219. @end quotation
  2220. Once you've installed a set of packages, you will want to periodically
  2221. @emph{upgrade} them to the latest and greatest version. To do that, you
  2222. will first pull the latest revision of Guix and its package collection:
  2223. @example
  2224. guix pull
  2225. @end example
  2226. The end result is a new @command{guix} command, under
  2227. @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
  2228. first time you run @command{guix pull}, be sure to follow the hint that
  2229. the command prints and, similar to what we saw above, paste these two
  2230. lines in your terminal and @file{.bash_profile}:
  2231. @example
  2232. GUIX_PROFILE="$HOME/.config/guix/current"
  2233. . "$GUIX_PROFILE/etc/profile"
  2234. @end example
  2235. @noindent
  2236. You must also instruct your shell to point to this new @command{guix}:
  2237. @example
  2238. hash guix
  2239. @end example
  2240. At this point, you're running a brand new Guix. You can thus go ahead
  2241. and actually upgrade all the packages you previously installed:
  2242. @example
  2243. guix upgrade
  2244. @end example
  2245. As you run this command, you will see that binaries are downloaded (or
  2246. perhaps some packages are built), and eventually you end up with the
  2247. upgraded packages. Should one of these upgraded packages not be to your
  2248. liking, remember you can always roll back!
  2249. You can display the exact revision of Guix you're currently using by
  2250. running:
  2251. @example
  2252. guix describe
  2253. @end example
  2254. The information it displays is @emph{all it takes to reproduce the exact
  2255. same Guix}, be it at a different point in time or on a different
  2256. machine.
  2257. @quotation Going further
  2258. @xref{Invoking guix pull}, for more information. @xref{Channels}, on
  2259. how to specify additional @dfn{channels} to pull packages from, how to
  2260. replicate Guix, and more. You may also find @command{time-machine}
  2261. handy (@pxref{Invoking guix time-machine}).
  2262. @end quotation
  2263. If you installed Guix System, one of the first things you'll want to do
  2264. is to upgrade your system. Once you've run @command{guix pull} to get
  2265. the latest Guix, you can upgrade the system like this:
  2266. @example
  2267. sudo guix system reconfigure /etc/config.scm
  2268. @end example
  2269. Upon completion, the system runs the latest versions of its software
  2270. packages. When you eventually reboot, you'll notice a sub-menu in the
  2271. bootloader that reads ``Old system generations'': it's what allows you
  2272. to boot @emph{an older generation of your system}, should the latest
  2273. generation be ``broken'' or otherwise unsatisfying. Just like for
  2274. packages, you can always @emph{roll back} to a previous generation
  2275. @emph{of the whole system}:
  2276. @example
  2277. sudo guix system roll-back
  2278. @end example
  2279. There are many things you'll probably want to tweak on your system:
  2280. adding new user accounts, adding new system services, fiddling with the
  2281. configuration of those services, etc. The system configuration is
  2282. @emph{entirely} described in the @file{/etc/config.scm} file.
  2283. @xref{Using the Configuration System}, to learn how to change it.
  2284. Now you know enough to get started!
  2285. @quotation Resources
  2286. The rest of this manual provides a reference for all things Guix. Here
  2287. are some additional resources you may find useful:
  2288. @itemize
  2289. @item
  2290. @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
  2291. ``how-to'' style of recipes for a variety of applications.
  2292. @item
  2293. The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
  2294. Card} lists in two pages most of the commands and options you'll ever
  2295. need.
  2296. @item
  2297. The web site contains @uref{https://guix.gnu.org/en/videos/,
  2298. instructional videos} covering topics such as everyday use of Guix, how
  2299. to get help, and how to become a contributor.
  2300. @item
  2301. @xref{Documentation}, to learn how to access documentation on your
  2302. computer.
  2303. @end itemize
  2304. We hope you will enjoy Guix as much as the community enjoys building it!
  2305. @end quotation
  2306. @c *********************************************************************
  2307. @node Package Management
  2308. @chapter Package Management
  2309. @cindex packages
  2310. The purpose of GNU Guix is to allow users to easily install, upgrade, and
  2311. remove software packages, without having to know about their build
  2312. procedures or dependencies. Guix also goes beyond this obvious set of
  2313. features.
  2314. This chapter describes the main features of Guix, as well as the
  2315. package management tools it provides. Along with the command-line
  2316. interface described below (@pxref{Invoking guix package, @code{guix
  2317. package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
  2318. emacs-guix, The Emacs-Guix Reference Manual}), after installing
  2319. @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
  2320. with it):
  2321. @example
  2322. guix install emacs-guix
  2323. @end example
  2324. @menu
  2325. * Features:: How Guix will make your life brighter.
  2326. * Invoking guix package:: Package installation, removal, etc.
  2327. * Substitutes:: Downloading pre-built binaries.
  2328. * Packages with Multiple Outputs:: Single source package, multiple outputs.
  2329. * Invoking guix gc:: Running the garbage collector.
  2330. * Invoking guix pull:: Fetching the latest Guix and distribution.
  2331. * Invoking guix time-machine:: Running an older revision of Guix.
  2332. * Inferiors:: Interacting with another revision of Guix.
  2333. * Invoking guix describe:: Display information about your Guix revision.
  2334. * Invoking guix archive:: Exporting and importing store files.
  2335. @end menu
  2336. @node Features
  2337. @section Features
  2338. Here we assume you've already made your first steps with Guix
  2339. (@pxref{Getting Started}) and would like to get an overview about what's
  2340. going on under the hood.
  2341. When using Guix, each package ends up in the @dfn{package store}, in its
  2342. own directory---something that resembles
  2343. @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
  2344. Instead of referring to these directories, users have their own
  2345. @dfn{profile}, which points to the packages that they actually want to
  2346. use. These profiles are stored within each user's home directory, at
  2347. @code{$HOME/.guix-profile}.
  2348. For example, @code{alice} installs GCC 4.7.2. As a result,
  2349. @file{/home/alice/.guix-profile/bin/gcc} points to
  2350. @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
  2351. @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
  2352. simply continues to point to
  2353. @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
  2354. coexist on the same system without any interference.
  2355. The @command{guix package} command is the central tool to manage
  2356. packages (@pxref{Invoking guix package}). It operates on the per-user
  2357. profiles, and can be used @emph{with normal user privileges}.
  2358. @cindex transactions
  2359. The command provides the obvious install, remove, and upgrade
  2360. operations. Each invocation is actually a @emph{transaction}: either
  2361. the specified operation succeeds, or nothing happens. Thus, if the
  2362. @command{guix package} process is terminated during the transaction,
  2363. or if a power outage occurs during the transaction, then the user's
  2364. profile remains in its previous state, and remains usable.
  2365. In addition, any package transaction may be @emph{rolled back}. So, if,
  2366. for example, an upgrade installs a new version of a package that turns
  2367. out to have a serious bug, users may roll back to the previous instance
  2368. of their profile, which was known to work well. Similarly, the global
  2369. system configuration on Guix is subject to
  2370. transactional upgrades and roll-back
  2371. (@pxref{Using the Configuration System}).
  2372. All packages in the package store may be @emph{garbage-collected}.
  2373. Guix can determine which packages are still referenced by user
  2374. profiles, and remove those that are provably no longer referenced
  2375. (@pxref{Invoking guix gc}). Users may also explicitly remove old
  2376. generations of their profile so that the packages they refer to can be
  2377. collected.
  2378. @cindex reproducibility
  2379. @cindex reproducible builds
  2380. Guix takes a @dfn{purely functional} approach to package
  2381. management, as described in the introduction (@pxref{Introduction}).
  2382. Each @file{/gnu/store} package directory name contains a hash of all the
  2383. inputs that were used to build that package---compiler, libraries, build
  2384. scripts, etc. This direct correspondence allows users to make sure a
  2385. given package installation matches the current state of their
  2386. distribution. It also helps maximize @dfn{build reproducibility}:
  2387. thanks to the isolated build environments that are used, a given build
  2388. is likely to yield bit-identical files when performed on different
  2389. machines (@pxref{Invoking guix-daemon, container}).
  2390. @cindex substitutes
  2391. This foundation allows Guix to support @dfn{transparent binary/source
  2392. deployment}. When a pre-built binary for a @file{/gnu/store} item is
  2393. available from an external source---a @dfn{substitute}, Guix just
  2394. downloads it and unpacks it;
  2395. otherwise, it builds the package from source, locally
  2396. (@pxref{Substitutes}). Because build results are usually bit-for-bit
  2397. reproducible, users do not have to trust servers that provide
  2398. substitutes: they can force a local build and @emph{challenge} providers
  2399. (@pxref{Invoking guix challenge}).
  2400. Control over the build environment is a feature that is also useful for
  2401. developers. The @command{guix environment} command allows developers of
  2402. a package to quickly set up the right development environment for their
  2403. package, without having to manually install the dependencies of the
  2404. package into their profile (@pxref{Invoking guix environment}).
  2405. @cindex replication, of software environments
  2406. @cindex provenance tracking, of software artifacts
  2407. All of Guix and its package definitions is version-controlled, and
  2408. @command{guix pull} allows you to ``travel in time'' on the history of Guix
  2409. itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
  2410. Guix instance on a different machine or at a later point in time, which in
  2411. turn allows you to @emph{replicate complete software environments}, while
  2412. retaining precise @dfn{provenance tracking} of the software.
  2413. @node Invoking guix package
  2414. @section Invoking @command{guix package}
  2415. @cindex installing packages
  2416. @cindex removing packages
  2417. @cindex package installation
  2418. @cindex package removal
  2419. The @command{guix package} command is the tool that allows users to
  2420. install, upgrade, and remove packages, as well as rolling back to
  2421. previous configurations. It operates only on the user's own profile,
  2422. and works with normal user privileges (@pxref{Features}). Its syntax
  2423. is:
  2424. @example
  2425. guix package @var{options}
  2426. @end example
  2427. @cindex transactions
  2428. Primarily, @var{options} specifies the operations to be performed during
  2429. the transaction. Upon completion, a new profile is created, but
  2430. previous @dfn{generations} of the profile remain available, should the user
  2431. want to roll back.
  2432. For example, to remove @code{lua} and install @code{guile} and
  2433. @code{guile-cairo} in a single transaction:
  2434. @example
  2435. guix package -r lua -i guile guile-cairo
  2436. @end example
  2437. @cindex aliases, for @command{guix package}
  2438. For your convenience, we also provide the following aliases:
  2439. @itemize
  2440. @item
  2441. @command{guix search} is an alias for @command{guix package -s},
  2442. @item
  2443. @command{guix install} is an alias for @command{guix package -i},
  2444. @item
  2445. @command{guix remove} is an alias for @command{guix package -r},
  2446. @item
  2447. @command{guix upgrade} is an alias for @command{guix package -u},
  2448. @item
  2449. and @command{guix show} is an alias for @command{guix package --show=}.
  2450. @end itemize
  2451. These aliases are less expressive than @command{guix package} and provide
  2452. fewer options, so in some cases you'll probably want to use @command{guix
  2453. package} directly.
  2454. @command{guix package} also supports a @dfn{declarative approach}
  2455. whereby the user specifies the exact set of packages to be available and
  2456. passes it @i{via} the @option{--manifest} option
  2457. (@pxref{profile-manifest, @option{--manifest}}).
  2458. @cindex profile
  2459. For each user, a symlink to the user's default profile is automatically
  2460. created in @file{$HOME/.guix-profile}. This symlink always points to the
  2461. current generation of the user's default profile. Thus, users can add
  2462. @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
  2463. variable, and so on.
  2464. @cindex search paths
  2465. If you are not using Guix System, consider adding the
  2466. following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
  2467. Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
  2468. shells get all the right environment variable definitions:
  2469. @example
  2470. GUIX_PROFILE="$HOME/.guix-profile" ; \
  2471. source "$GUIX_PROFILE/etc/profile"
  2472. @end example
  2473. In a multi-user setup, user profiles are stored in a place registered as
  2474. a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
  2475. to (@pxref{Invoking guix gc}). That directory is normally
  2476. @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
  2477. @var{localstatedir} is the value passed to @code{configure} as
  2478. @option{--localstatedir}, and @var{user} is the user name. The
  2479. @file{per-user} directory is created when @command{guix-daemon} is
  2480. started, and the @var{user} sub-directory is created by @command{guix
  2481. package}.
  2482. The @var{options} can be among the following:
  2483. @table @code
  2484. @item --install=@var{package} @dots{}
  2485. @itemx -i @var{package} @dots{}
  2486. Install the specified @var{package}s.
  2487. Each @var{package} may specify either a simple package name, such as
  2488. @code{guile}, or a package name followed by an at-sign and version number,
  2489. such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
  2490. case, the newest version prefixed by @code{1.8} is selected).
  2491. If no version number is specified, the
  2492. newest available version will be selected. In addition, @var{package}
  2493. may contain a colon, followed by the name of one of the outputs of the
  2494. package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
  2495. (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
  2496. name (and optionally version) are searched for among the GNU
  2497. distribution modules (@pxref{Package Modules}).
  2498. @cindex propagated inputs
  2499. Sometimes packages have @dfn{propagated inputs}: these are dependencies
  2500. that automatically get installed along with the required package
  2501. (@pxref{package-propagated-inputs, @code{propagated-inputs} in
  2502. @code{package} objects}, for information about propagated inputs in
  2503. package definitions).
  2504. @anchor{package-cmd-propagated-inputs}
  2505. An example is the GNU MPC library: its C header files refer to those of
  2506. the GNU MPFR library, which in turn refer to those of the GMP library.
  2507. Thus, when installing MPC, the MPFR and GMP libraries also get installed
  2508. in the profile; removing MPC also removes MPFR and GMP---unless they had
  2509. also been explicitly installed by the user.
  2510. Besides, packages sometimes rely on the definition of environment
  2511. variables for their search paths (see explanation of
  2512. @option{--search-paths} below). Any missing or possibly incorrect
  2513. environment variable definitions are reported here.
  2514. @item --install-from-expression=@var{exp}
  2515. @itemx -e @var{exp}
  2516. Install the package @var{exp} evaluates to.
  2517. @var{exp} must be a Scheme expression that evaluates to a
  2518. @code{<package>} object. This option is notably useful to disambiguate
  2519. between same-named variants of a package, with expressions such as
  2520. @code{(@@ (gnu packages base) guile-final)}.
  2521. Note that this option installs the first output of the specified
  2522. package, which may be insufficient when needing a specific output of a
  2523. multiple-output package.
  2524. @item --install-from-file=@var{file}
  2525. @itemx -f @var{file}
  2526. Install the package that the code within @var{file} evaluates to.
  2527. As an example, @var{file} might contain a definition like this
  2528. (@pxref{Defining Packages}):
  2529. @lisp
  2530. @include package-hello.scm
  2531. @end lisp
  2532. Developers may find it useful to include such a @file{guix.scm} file
  2533. in the root of their project source tree that can be used to test
  2534. development snapshots and create reproducible development environments
  2535. (@pxref{Invoking guix environment}).
  2536. The @var{file} may also contain a JSON representation of one or more
  2537. package definitions. Running @code{guix package -f} on
  2538. @file{hello.json} with the following contents would result in installing
  2539. the package @code{greeter} after building @code{myhello}:
  2540. @example
  2541. @verbatiminclude package-hello.json
  2542. @end example
  2543. @item --remove=@var{package} @dots{}
  2544. @itemx -r @var{package} @dots{}
  2545. Remove the specified @var{package}s.
  2546. As for @option{--install}, each @var{package} may specify a version number
  2547. and/or output name in addition to the package name. For instance,
  2548. @samp{-r glibc:debug} would remove the @code{debug} output of
  2549. @code{glibc}.
  2550. @item --upgrade[=@var{regexp} @dots{}]
  2551. @itemx -u [@var{regexp} @dots{}]
  2552. @cindex upgrading packages
  2553. Upgrade all the installed packages. If one or more @var{regexp}s are
  2554. specified, upgrade only installed packages whose name matches a
  2555. @var{regexp}. Also see the @option{--do-not-upgrade} option below.
  2556. Note that this upgrades package to the latest version of packages found
  2557. in the distribution currently installed. To update your distribution,
  2558. you should regularly run @command{guix pull} (@pxref{Invoking guix
  2559. pull}).
  2560. @cindex package transformations, upgrades
  2561. When upgrading, package transformations that were originally applied
  2562. when creating the profile are automatically re-applied (@pxref{Package
  2563. Transformation Options}). For example, assume you first installed Emacs
  2564. from the tip of its development branch with:
  2565. @example
  2566. guix install emacs-next --with-branch=emacs-next=master
  2567. @end example
  2568. Next time you run @command{guix upgrade}, Guix will again pull the tip
  2569. of the Emacs development branch and build @code{emacs-next} from that
  2570. checkout.
  2571. Note that transformation options such as @option{--with-branch} and
  2572. @option{--with-source} depend on external state; it is up to you to
  2573. ensure that they work as expected. You can also discard a
  2574. transformations that apply to a package by running:
  2575. @example
  2576. guix install @var{package}
  2577. @end example
  2578. @item --do-not-upgrade[=@var{regexp} @dots{}]
  2579. When used together with the @option{--upgrade} option, do @emph{not}
  2580. upgrade any packages whose name matches a @var{regexp}. For example, to
  2581. upgrade all packages in the current profile except those containing the
  2582. substring ``emacs'':
  2583. @example
  2584. $ guix package --upgrade . --do-not-upgrade emacs
  2585. @end example
  2586. @item @anchor{profile-manifest}--manifest=@var{file}
  2587. @itemx -m @var{file}
  2588. @cindex profile declaration
  2589. @cindex profile manifest
  2590. Create a new generation of the profile from the manifest object
  2591. returned by the Scheme code in @var{file}. This option can be repeated
  2592. several times, in which case the manifests are concatenated.
  2593. This allows you to @emph{declare} the profile's contents rather than
  2594. constructing it through a sequence of @option{--install} and similar
  2595. commands. The advantage is that @var{file} can be put under version
  2596. control, copied to different machines to reproduce the same profile, and
  2597. so on.
  2598. @c FIXME: Add reference to (guix profile) documentation when available.
  2599. @var{file} must return a @dfn{manifest} object, which is roughly a list
  2600. of packages:
  2601. @findex packages->manifest
  2602. @lisp
  2603. (use-package-modules guile emacs)
  2604. (packages->manifest
  2605. (list emacs
  2606. guile-2.0
  2607. ;; Use a specific package output.
  2608. (list guile-2.0 "debug")))
  2609. @end lisp
  2610. @findex specifications->manifest
  2611. In this example we have to know which modules define the @code{emacs}
  2612. and @code{guile-2.0} variables to provide the right
  2613. @code{use-package-modules} line, which can be cumbersome. We can
  2614. instead provide regular package specifications and let
  2615. @code{specifications->manifest} look up the corresponding package
  2616. objects, like this:
  2617. @lisp
  2618. (specifications->manifest
  2619. '("emacs" "guile@@2.2" "guile@@2.2:debug"))
  2620. @end lisp
  2621. @item --roll-back
  2622. @cindex rolling back
  2623. @cindex undoing transactions
  2624. @cindex transactions, undoing
  2625. Roll back to the previous @dfn{generation} of the profile---i.e., undo
  2626. the last transaction.
  2627. When combined with options such as @option{--install}, roll back occurs
  2628. before any other actions.
  2629. When rolling back from the first generation that actually contains
  2630. installed packages, the profile is made to point to the @dfn{zeroth
  2631. generation}, which contains no files apart from its own metadata.
  2632. After having rolled back, installing, removing, or upgrading packages
  2633. overwrites previous future generations. Thus, the history of the
  2634. generations in a profile is always linear.
  2635. @item --switch-generation=@var{pattern}
  2636. @itemx -S @var{pattern}
  2637. @cindex generations
  2638. Switch to a particular generation defined by @var{pattern}.
  2639. @var{pattern} may be either a generation number or a number prefixed
  2640. with ``+'' or ``-''. The latter means: move forward/backward by a
  2641. specified number of generations. For example, if you want to return to
  2642. the latest generation after @option{--roll-back}, use
  2643. @option{--switch-generation=+1}.
  2644. The difference between @option{--roll-back} and
  2645. @option{--switch-generation=-1} is that @option{--switch-generation} will
  2646. not make a zeroth generation, so if a specified generation does not
  2647. exist, the current generation will not be changed.
  2648. @item --search-paths[=@var{kind}]
  2649. @cindex search paths
  2650. Report environment variable definitions, in Bash syntax, that may be
  2651. needed in order to use the set of installed packages. These environment
  2652. variables are used to specify @dfn{search paths} for files used by some
  2653. of the installed packages.
  2654. For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
  2655. environment variables to be defined so it can look for headers and
  2656. libraries in the user's profile (@pxref{Environment Variables,,, gcc,
  2657. Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
  2658. library are installed in the profile, then @option{--search-paths} will
  2659. suggest setting these variables to @file{@var{profile}/include} and
  2660. @file{@var{profile}/lib}, respectively.
  2661. The typical use case is to define these environment variables in the
  2662. shell:
  2663. @example
  2664. $ eval `guix package --search-paths`
  2665. @end example
  2666. @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
  2667. meaning that the returned environment variable definitions will either
  2668. be exact settings, or prefixes or suffixes of the current value of these
  2669. variables. When omitted, @var{kind} defaults to @code{exact}.
  2670. This option can also be used to compute the @emph{combined} search paths
  2671. of several profiles. Consider this example:
  2672. @example
  2673. $ guix package -p foo -i guile
  2674. $ guix package -p bar -i guile-json
  2675. $ guix package -p foo -p bar --search-paths
  2676. @end example
  2677. The last command above reports about the @env{GUILE_LOAD_PATH}
  2678. variable, even though, taken individually, neither @file{foo} nor
  2679. @file{bar} would lead to that recommendation.
  2680. @item --profile=@var{profile}
  2681. @itemx -p @var{profile}
  2682. Use @var{profile} instead of the user's default profile.
  2683. @var{profile} must be the name of a file that will be created upon
  2684. completion. Concretely, @var{profile} will be a mere symbolic link
  2685. (``symlink'') pointing to the actual profile where packages are
  2686. installed:
  2687. @example
  2688. $ guix install hello -p ~/code/my-profile
  2689. @dots{}
  2690. $ ~/code/my-profile/bin/hello
  2691. Hello, world!
  2692. @end example
  2693. All it takes to get rid of the profile is to remove this symlink and its
  2694. siblings that point to specific generations:
  2695. @example
  2696. $ rm ~/code/my-profile ~/code/my-profile-*-link
  2697. @end example
  2698. @item --list-profiles
  2699. List all the user's profiles:
  2700. @example
  2701. $ guix package --list-profiles
  2702. /home/charlie/.guix-profile
  2703. /home/charlie/code/my-profile
  2704. /home/charlie/code/devel-profile
  2705. /home/charlie/tmp/test
  2706. @end example
  2707. When running as root, list all the profiles of all the users.
  2708. @cindex collisions, in a profile
  2709. @cindex colliding packages in profiles
  2710. @cindex profile collisions
  2711. @item --allow-collisions
  2712. Allow colliding packages in the new profile. Use at your own risk!
  2713. By default, @command{guix package} reports as an error @dfn{collisions}
  2714. in the profile. Collisions happen when two or more different versions
  2715. or variants of a given package end up in the profile.
  2716. @item --bootstrap
  2717. Use the bootstrap Guile to build the profile. This option is only
  2718. useful to distribution developers.
  2719. @end table
  2720. In addition to these actions, @command{guix package} supports the
  2721. following options to query the current state of a profile, or the
  2722. availability of packages:
  2723. @table @option
  2724. @item --search=@var{regexp}
  2725. @itemx -s @var{regexp}
  2726. @anchor{guix-search}
  2727. @cindex searching for packages
  2728. List the available packages whose name, synopsis, or description matches
  2729. @var{regexp} (in a case-insensitive fashion), sorted by relevance.
  2730. Print all the metadata of matching packages in
  2731. @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
  2732. GNU recutils manual}).
  2733. This allows specific fields to be extracted using the @command{recsel}
  2734. command, for instance:
  2735. @example
  2736. $ guix package -s malloc | recsel -p name,version,relevance
  2737. name: jemalloc
  2738. version: 4.5.0
  2739. relevance: 6
  2740. name: glibc
  2741. version: 2.25
  2742. relevance: 1
  2743. name: libgc
  2744. version: 7.6.0
  2745. relevance: 1
  2746. @end example
  2747. Similarly, to show the name of all the packages available under the
  2748. terms of the GNU@tie{}LGPL version 3:
  2749. @example
  2750. $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
  2751. name: elfutils
  2752. name: gmp
  2753. @dots{}
  2754. @end example
  2755. It is also possible to refine search results using several @code{-s} flags to
  2756. @command{guix package}, or several arguments to @command{guix search}. For
  2757. example, the following command returns a list of board games (this time using
  2758. the @command{guix search} alias):
  2759. @example
  2760. $ guix search '\<board\>' game | recsel -p name
  2761. name: gnubg
  2762. @dots{}
  2763. @end example
  2764. If we were to omit @code{-s game}, we would also get software packages
  2765. that deal with printed circuit boards; removing the angle brackets
  2766. around @code{board} would further add packages that have to do with
  2767. keyboards.
  2768. And now for a more elaborate example. The following command searches
  2769. for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
  2770. libraries, and prints the name and synopsis of the matching packages:
  2771. @example
  2772. $ guix search crypto library | \
  2773. recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
  2774. @end example
  2775. @noindent
  2776. @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
  2777. information on @dfn{selection expressions} for @code{recsel -e}.
  2778. @item --show=@var{package}
  2779. Show details about @var{package}, taken from the list of available packages, in
  2780. @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
  2781. recutils manual}).
  2782. @example
  2783. $ guix package --show=python | recsel -p name,version
  2784. name: python
  2785. version: 2.7.6
  2786. name: python
  2787. version: 3.3.5
  2788. @end example
  2789. You may also specify the full name of a package to only get details about a
  2790. specific version of it (this time using the @command{guix show} alias):
  2791. @example
  2792. $ guix show python@@3.4 | recsel -p name,version
  2793. name: python
  2794. version: 3.4.3
  2795. @end example
  2796. @item --list-installed[=@var{regexp}]
  2797. @itemx -I [@var{regexp}]
  2798. List the currently installed packages in the specified profile, with the
  2799. most recently installed packages shown last. When @var{regexp} is
  2800. specified, list only installed packages whose name matches @var{regexp}.
  2801. For each installed package, print the following items, separated by
  2802. tabs: the package name, its version string, the part of the package that
  2803. is installed (for instance, @code{out} for the default output,
  2804. @code{include} for its headers, etc.), and the path of this package in
  2805. the store.
  2806. @item --list-available[=@var{regexp}]
  2807. @itemx -A [@var{regexp}]
  2808. List packages currently available in the distribution for this system
  2809. (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
  2810. available packages whose name matches @var{regexp}.
  2811. For each package, print the following items separated by tabs: its name,
  2812. its version string, the parts of the package (@pxref{Packages with
  2813. Multiple Outputs}), and the source location of its definition.
  2814. @item --list-generations[=@var{pattern}]
  2815. @itemx -l [@var{pattern}]
  2816. @cindex generations
  2817. Return a list of generations along with their creation dates; for each
  2818. generation, show the installed packages, with the most recently
  2819. installed packages shown last. Note that the zeroth generation is never
  2820. shown.
  2821. For each installed package, print the following items, separated by
  2822. tabs: the name of a package, its version string, the part of the package
  2823. that is installed (@pxref{Packages with Multiple Outputs}), and the
  2824. location of this package in the store.
  2825. When @var{pattern} is used, the command returns only matching
  2826. generations. Valid patterns include:
  2827. @itemize
  2828. @item @emph{Integers and comma-separated integers}. Both patterns denote
  2829. generation numbers. For instance, @option{--list-generations=1} returns
  2830. the first one.
  2831. And @option{--list-generations=1,8,2} outputs three generations in the
  2832. specified order. Neither spaces nor trailing commas are allowed.
  2833. @item @emph{Ranges}. @option{--list-generations=2..9} prints the
  2834. specified generations and everything in between. Note that the start of
  2835. a range must be smaller than its end.
  2836. It is also possible to omit the endpoint. For example,
  2837. @option{--list-generations=2..}, returns all generations starting from the
  2838. second one.
  2839. @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
  2840. or months by passing an integer along with the first letter of the
  2841. duration. For example, @option{--list-generations=20d} lists generations
  2842. that are up to 20 days old.
  2843. @end itemize
  2844. @item --delete-generations[=@var{pattern}]
  2845. @itemx -d [@var{pattern}]
  2846. When @var{pattern} is omitted, delete all generations except the current
  2847. one.
  2848. This command accepts the same patterns as @option{--list-generations}.
  2849. When @var{pattern} is specified, delete the matching generations. When
  2850. @var{pattern} specifies a duration, generations @emph{older} than the
  2851. specified duration match. For instance, @option{--delete-generations=1m}
  2852. deletes generations that are more than one month old.
  2853. If the current generation matches, it is @emph{not} deleted. Also, the
  2854. zeroth generation is never deleted.
  2855. Note that deleting generations prevents rolling back to them.
  2856. Consequently, this command must be used with care.
  2857. @end table
  2858. Finally, since @command{guix package} may actually start build
  2859. processes, it supports all the common build options (@pxref{Common Build
  2860. Options}). It also supports package transformation options, such as
  2861. @option{--with-source}, and preserves them across upgrades
  2862. (@pxref{Package Transformation Options}).
  2863. @node Substitutes
  2864. @section Substitutes
  2865. @cindex substitutes
  2866. @cindex pre-built binaries
  2867. Guix supports transparent source/binary deployment, which means that it
  2868. can either build things locally, or download pre-built items from a
  2869. server, or both. We call these pre-built items @dfn{substitutes}---they
  2870. are substitutes for local build results. In many cases, downloading a
  2871. substitute is much faster than building things locally.
  2872. Substitutes can be anything resulting from a derivation build
  2873. (@pxref{Derivations}). Of course, in the common case, they are
  2874. pre-built package binaries, but source tarballs, for instance, which
  2875. also result from derivation builds, can be available as substitutes.
  2876. @menu
  2877. * Official Substitute Server:: One particular source of substitutes.
  2878. * Substitute Server Authorization:: How to enable or disable substitutes.
  2879. * Getting Substitutes from Other Servers:: Substitute diversity.
  2880. * Substitute Authentication:: How Guix verifies substitutes.
  2881. * Proxy Settings:: How to get substitutes via proxy.
  2882. * Substitution Failure:: What happens when substitution fails.
  2883. * On Trusting Binaries:: How can you trust that binary blob?
  2884. @end menu
  2885. @node Official Substitute Server
  2886. @subsection Official Substitute Server
  2887. @cindex build farm
  2888. The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
  2889. that builds packages from Guix continuously for some
  2890. architectures, and makes them available as substitutes. This is the
  2891. default source of substitutes; it can be overridden by passing the
  2892. @option{--substitute-urls} option either to @command{guix-daemon}
  2893. (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
  2894. or to client tools such as @command{guix package}
  2895. (@pxref{client-substitute-urls,, client @option{--substitute-urls}
  2896. option}).
  2897. Substitute URLs can be either HTTP or HTTPS.
  2898. HTTPS is recommended because communications are encrypted; conversely,
  2899. using HTTP makes all communications visible to an eavesdropper, who
  2900. could use the information gathered to determine, for instance, whether
  2901. your system has unpatched security vulnerabilities.
  2902. Substitutes from the official build farm are enabled by default when
  2903. using Guix System (@pxref{GNU Distribution}). However,
  2904. they are disabled by default when using Guix on a foreign distribution,
  2905. unless you have explicitly enabled them via one of the recommended
  2906. installation steps (@pxref{Installation}). The following paragraphs
  2907. describe how to enable or disable substitutes for the official build
  2908. farm; the same procedure can also be used to enable substitutes for any
  2909. other substitute server.
  2910. @node Substitute Server Authorization
  2911. @subsection Substitute Server Authorization
  2912. @cindex security
  2913. @cindex substitutes, authorization thereof
  2914. @cindex access control list (ACL), for substitutes
  2915. @cindex ACL (access control list), for substitutes
  2916. To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
  2917. mirror thereof, you
  2918. must add its public key to the access control list (ACL) of archive
  2919. imports, using the @command{guix archive} command (@pxref{Invoking guix
  2920. archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
  2921. be compromised and to serve genuine substitutes.
  2922. @quotation Note
  2923. If you are using Guix System, you can skip this section: Guix System
  2924. authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
  2925. @end quotation
  2926. The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
  2927. @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
  2928. the installation prefix of Guix. If you installed Guix from source,
  2929. make sure you checked the GPG signature of
  2930. @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
  2931. Then, you can run something like this:
  2932. @example
  2933. # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
  2934. @end example
  2935. Once this is in place, the output of a command like @code{guix build}
  2936. should change from something like:
  2937. @example
  2938. $ guix build emacs --dry-run
  2939. The following derivations would be built:
  2940. /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
  2941. /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
  2942. /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
  2943. /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
  2944. @dots{}
  2945. @end example
  2946. @noindent
  2947. to something like:
  2948. @example
  2949. $ guix build emacs --dry-run
  2950. 112.3 MB would be downloaded:
  2951. /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
  2952. /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
  2953. /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
  2954. /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
  2955. @dots{}
  2956. @end example
  2957. @noindent
  2958. The text changed from ``The following derivations would be built'' to
  2959. ``112.3 MB would be downloaded''. This indicates that substitutes from
  2960. @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
  2961. possible, for future builds.
  2962. @cindex substitutes, how to disable
  2963. The substitute mechanism can be disabled globally by running
  2964. @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
  2965. guix-daemon}). It can also be disabled temporarily by passing the
  2966. @option{--no-substitutes} option to @command{guix package},
  2967. @command{guix build}, and other command-line tools.
  2968. @node Getting Substitutes from Other Servers
  2969. @subsection Getting Substitutes from Other Servers
  2970. @cindex substitute servers, adding more
  2971. Guix can look up and fetch substitutes from several servers. This is
  2972. useful when you are using packages from additional channels for which
  2973. the official server does not have substitutes but another server
  2974. provides them. Another situation where this is useful is when you would
  2975. prefer to download from your organization's substitute server, resorting
  2976. to the official server only as a fallback or dismissing it altogether.
  2977. You can give Guix a list of substitute server URLs and it will check
  2978. them in the specified order. You also need to explicitly authorize the
  2979. public keys of substitute servers to instruct Guix to accept the
  2980. substitutes they sign.
  2981. On Guix System, this is achieved by modifying the configuration of the
  2982. @code{guix} service. Since the @code{guix} service is part of the
  2983. default lists of services, @code{%base-services} and
  2984. @code{%desktop-services}, you can use @code{modify-services} to change
  2985. its configuration and add the URLs and substitute keys that you want
  2986. (@pxref{Service Reference, @code{modify-services}}).
  2987. As an example, suppose you want to fetch substitutes from
  2988. @code{guix.example.org} and to authorize the signing key of that server,
  2989. in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
  2990. resulting operating system configuration will look something like:
  2991. @lisp
  2992. (operating-system
  2993. ;; @dots{}
  2994. (services
  2995. ;; Assume we're starting from '%desktop-services'. Replace it
  2996. ;; with the list of services you're actually using.
  2997. (modify-services %desktop-services
  2998. (guix-service-type config =>
  2999. (guix-configuration
  3000. (inherit config)
  3001. (substitute-urls
  3002. (append (list "https://guix.example.org")
  3003. %default-substitute-urls))
  3004. (authorized-keys
  3005. (append (list (local-file "./key.pub"))
  3006. %default-authorized-guix-keys)))))))
  3007. @end lisp
  3008. This assumes that the file @file{key.pub} contains the signing key of
  3009. @code{guix.example.org}. With this change in place in your operating
  3010. system configuration file (say @file{/etc/config.scm}), you can
  3011. reconfigure and restart the @code{guix-daemon} service or reboot so the
  3012. changes take effect:
  3013. @example
  3014. $ sudo guix system reconfigure /etc/config.scm
  3015. $ sudo herd restart guix-daemon
  3016. @end example
  3017. If you're running Guix on a ``foreign distro'', you would instead take
  3018. the following steps to get substitutes from additional servers:
  3019. @enumerate
  3020. @item
  3021. Edit the service configuration file for @code{guix-daemon}; when using
  3022. systemd, this is normally
  3023. @file{/etc/systemd/system/guix-daemon.service}. Add the
  3024. @option{--substitute-urls} option on the @command{guix-daemon} command
  3025. line and list the URLs of interest (@pxref{daemon-substitute-urls,
  3026. @code{guix-daemon --substitute-urls}}):
  3027. @example
  3028. @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
  3029. @end example
  3030. @item
  3031. Restart the daemon. For systemd, it goes like this:
  3032. @example
  3033. systemctl daemon-reload
  3034. systemctl restart guix-daemon.service
  3035. @end example
  3036. @item
  3037. Authorize the key of the new server (@pxref{Invoking guix archive}):
  3038. @example
  3039. guix archive --authorize < key.pub
  3040. @end example
  3041. Again this assumes @file{key.pub} contains the public key that
  3042. @code{guix.example.org} uses to sign substitutes.
  3043. @end enumerate
  3044. Now you're all set! Substitutes will be preferably taken from
  3045. @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
  3046. as a fallback. Of course you can list as many substitute servers as you
  3047. like, with the caveat that substitute lookup can be slowed down if too
  3048. many servers need to be contacted.
  3049. Note that there are also situations where one may want to add the URL of
  3050. a substitute server @emph{without} authorizing its key.
  3051. @xref{Substitute Authentication}, to understand this fine point.
  3052. @node Substitute Authentication
  3053. @subsection Substitute Authentication
  3054. @cindex digital signatures
  3055. Guix detects and raises an error when attempting to use a substitute
  3056. that has been tampered with. Likewise, it ignores substitutes that are
  3057. not signed, or that are not signed by one of the keys listed in the ACL.
  3058. There is one exception though: if an unauthorized server provides
  3059. substitutes that are @emph{bit-for-bit identical} to those provided by
  3060. an authorized server, then the unauthorized server becomes eligible for
  3061. downloads. For example, assume we have chosen two substitute servers
  3062. with this option:
  3063. @example
  3064. --substitute-urls="https://a.example.org https://b.example.org"
  3065. @end example
  3066. @noindent
  3067. @cindex reproducible builds
  3068. If the ACL contains only the key for @samp{b.example.org}, and if
  3069. @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
  3070. then Guix will download substitutes from @samp{a.example.org} because it
  3071. comes first in the list and can be considered a mirror of
  3072. @samp{b.example.org}. In practice, independent build machines usually
  3073. produce the same binaries, thanks to bit-reproducible builds (see
  3074. below).
  3075. When using HTTPS, the server's X.509 certificate is @emph{not} validated
  3076. (in other words, the server is not authenticated), contrary to what
  3077. HTTPS clients such as Web browsers usually do. This is because Guix
  3078. authenticates substitute information itself, as explained above, which
  3079. is what we care about (whereas X.509 certificates are about
  3080. authenticating bindings between domain names and public keys).
  3081. @node Proxy Settings
  3082. @subsection Proxy Settings
  3083. @vindex http_proxy
  3084. @vindex https_proxy
  3085. Substitutes are downloaded over HTTP or HTTPS@. The @env{http_proxy} and
  3086. @env{https_proxy} environment variables can be set in the environment of
  3087. @command{guix-daemon} and are honored for downloads of substitutes.
  3088. Note that the value of those environment variables in the environment
  3089. where @command{guix build}, @command{guix package}, and other client
  3090. commands are run has @emph{absolutely no effect}.
  3091. @node Substitution Failure
  3092. @subsection Substitution Failure
  3093. Even when a substitute for a derivation is available, sometimes the
  3094. substitution attempt will fail. This can happen for a variety of
  3095. reasons: the substitute server might be offline, the substitute may
  3096. recently have been deleted, the connection might have been interrupted,
  3097. etc.
  3098. When substitutes are enabled and a substitute for a derivation is
  3099. available, but the substitution attempt fails, Guix will attempt to
  3100. build the derivation locally depending on whether or not
  3101. @option{--fallback} was given (@pxref{fallback-option,, common build
  3102. option @option{--fallback}}). Specifically, if @option{--fallback} was
  3103. omitted, then no local build will be performed, and the derivation is
  3104. considered to have failed. However, if @option{--fallback} was given,
  3105. then Guix will attempt to build the derivation locally, and the success
  3106. or failure of the derivation depends on the success or failure of the
  3107. local build. Note that when substitutes are disabled or no substitute
  3108. is available for the derivation in question, a local build will
  3109. @emph{always} be performed, regardless of whether or not
  3110. @option{--fallback} was given.
  3111. To get an idea of how many substitutes are available right now, you can
  3112. try running the @command{guix weather} command (@pxref{Invoking guix
  3113. weather}). This command provides statistics on the substitutes provided
  3114. by a server.
  3115. @node On Trusting Binaries
  3116. @subsection On Trusting Binaries
  3117. @cindex trust, of pre-built binaries
  3118. Today, each individual's control over their own computing is at the
  3119. mercy of institutions, corporations, and groups with enough power and
  3120. determination to subvert the computing infrastructure and exploit its
  3121. weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
  3122. convenient, we encourage users to also build on their own, or even run
  3123. their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
  3124. interesting target. One way to help is by publishing the software you
  3125. build using @command{guix publish} so that others have one more choice
  3126. of server to download substitutes from (@pxref{Invoking guix publish}).
  3127. Guix has the foundations to maximize build reproducibility
  3128. (@pxref{Features}). In most cases, independent builds of a given
  3129. package or derivation should yield bit-identical results. Thus, through
  3130. a diverse set of independent package builds, we can strengthen the
  3131. integrity of our systems. The @command{guix challenge} command aims to
  3132. help users assess substitute servers, and to assist developers in
  3133. finding out about non-deterministic package builds (@pxref{Invoking guix
  3134. challenge}). Similarly, the @option{--check} option of @command{guix
  3135. build} allows users to check whether previously-installed substitutes
  3136. are genuine by rebuilding them locally (@pxref{build-check,
  3137. @command{guix build --check}}).
  3138. In the future, we want Guix to have support to publish and retrieve
  3139. binaries to/from other users, in a peer-to-peer fashion. If you would
  3140. like to discuss this project, join us on @email{guix-devel@@gnu.org}.
  3141. @node Packages with Multiple Outputs
  3142. @section Packages with Multiple Outputs
  3143. @cindex multiple-output packages
  3144. @cindex package outputs
  3145. @cindex outputs
  3146. Often, packages defined in Guix have a single @dfn{output}---i.e., the
  3147. source package leads to exactly one directory in the store. When running
  3148. @command{guix install glibc}, one installs the default output of the
  3149. GNU libc package; the default output is called @code{out}, but its name
  3150. can be omitted as shown in this command. In this particular case, the
  3151. default output of @code{glibc} contains all the C header files, shared
  3152. libraries, static libraries, Info documentation, and other supporting
  3153. files.
  3154. Sometimes it is more appropriate to separate the various types of files
  3155. produced from a single source package into separate outputs. For
  3156. instance, the GLib C library (used by GTK+ and related packages)
  3157. installs more than 20 MiB of reference documentation as HTML pages.
  3158. To save space for users who do not need it, the documentation goes to a
  3159. separate output, called @code{doc}. To install the main GLib output,
  3160. which contains everything but the documentation, one would run:
  3161. @example
  3162. guix install glib
  3163. @end example
  3164. @cindex documentation
  3165. The command to install its documentation is:
  3166. @example
  3167. guix install glib:doc
  3168. @end example
  3169. Some packages install programs with different ``dependency footprints''.
  3170. For instance, the WordNet package installs both command-line tools and
  3171. graphical user interfaces (GUIs). The former depend solely on the C
  3172. library, whereas the latter depend on Tcl/Tk and the underlying X
  3173. libraries. In this case, we leave the command-line tools in the default
  3174. output, whereas the GUIs are in a separate output. This allows users
  3175. who do not need the GUIs to save space. The @command{guix size} command
  3176. can help find out about such situations (@pxref{Invoking guix size}).
  3177. @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
  3178. There are several such multiple-output packages in the GNU distribution.
  3179. Other conventional output names include @code{lib} for libraries and
  3180. possibly header files, @code{bin} for stand-alone programs, and
  3181. @code{debug} for debugging information (@pxref{Installing Debugging
  3182. Files}). The outputs of a packages are listed in the third column of
  3183. the output of @command{guix package --list-available} (@pxref{Invoking
  3184. guix package}).
  3185. @node Invoking guix gc
  3186. @section Invoking @command{guix gc}
  3187. @cindex garbage collector
  3188. @cindex disk space
  3189. Packages that are installed, but not used, may be @dfn{garbage-collected}.
  3190. The @command{guix gc} command allows users to explicitly run the garbage
  3191. collector to reclaim space from the @file{/gnu/store} directory. It is
  3192. the @emph{only} way to remove files from @file{/gnu/store}---removing
  3193. files or directories manually may break it beyond repair!
  3194. @cindex GC roots
  3195. @cindex garbage collector roots
  3196. The garbage collector has a set of known @dfn{roots}: any file under
  3197. @file{/gnu/store} reachable from a root is considered @dfn{live} and
  3198. cannot be deleted; any other file is considered @dfn{dead} and may be
  3199. deleted. The set of garbage collector roots (``GC roots'' for short)
  3200. includes default user profiles; by default, the symlinks under
  3201. @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
  3202. added with @command{guix build --root}, for example (@pxref{Invoking
  3203. guix build}). The @command{guix gc --list-roots} command lists them.
  3204. Prior to running @code{guix gc --collect-garbage} to make space, it is
  3205. often useful to remove old generations from user profiles; that way, old
  3206. package builds referenced by those generations can be reclaimed. This
  3207. is achieved by running @code{guix package --delete-generations}
  3208. (@pxref{Invoking guix package}).
  3209. Our recommendation is to run a garbage collection periodically, or when
  3210. you are short on disk space. For instance, to guarantee that at least
  3211. 5@tie{}GB are available on your disk, simply run:
  3212. @example
  3213. guix gc -F 5G
  3214. @end example
  3215. It is perfectly safe to run as a non-interactive periodic job
  3216. (@pxref{Scheduled Job Execution}, for how to set up such a job).
  3217. Running @command{guix gc} with no arguments will collect as
  3218. much garbage as it can, but that is often inconvenient: you may find
  3219. yourself having to rebuild or re-download software that is ``dead'' from
  3220. the GC viewpoint but that is necessary to build other pieces of
  3221. software---e.g., the compiler tool chain.
  3222. The @command{guix gc} command has three modes of operation: it can be
  3223. used to garbage-collect any dead files (the default), to delete specific
  3224. files (the @option{--delete} option), to print garbage-collector
  3225. information, or for more advanced queries. The garbage collection
  3226. options are as follows:
  3227. @table @code
  3228. @item --collect-garbage[=@var{min}]
  3229. @itemx -C [@var{min}]
  3230. Collect garbage---i.e., unreachable @file{/gnu/store} files and
  3231. sub-directories. This is the default operation when no option is
  3232. specified.
  3233. When @var{min} is given, stop once @var{min} bytes have been collected.
  3234. @var{min} may be a number of bytes, or it may include a unit as a
  3235. suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
  3236. (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
  3237. When @var{min} is omitted, collect all the garbage.
  3238. @item --free-space=@var{free}
  3239. @itemx -F @var{free}
  3240. Collect garbage until @var{free} space is available under
  3241. @file{/gnu/store}, if possible; @var{free} denotes storage space, such
  3242. as @code{500MiB}, as described above.
  3243. When @var{free} or more is already available in @file{/gnu/store}, do
  3244. nothing and exit immediately.
  3245. @item --delete-generations[=@var{duration}]
  3246. @itemx -d [@var{duration}]
  3247. Before starting the garbage collection process, delete all the generations
  3248. older than @var{duration}, for all the user profiles; when run as root, this
  3249. applies to all the profiles @emph{of all the users}.
  3250. For example, this command deletes all the generations of all your profiles
  3251. that are older than 2 months (except generations that are current), and then
  3252. proceeds to free space until at least 10 GiB are available:
  3253. @example
  3254. guix gc -d 2m -F 10G
  3255. @end example
  3256. @item --delete
  3257. @itemx -D
  3258. Attempt to delete all the store files and directories specified as
  3259. arguments. This fails if some of the files are not in the store, or if
  3260. they are still live.
  3261. @item --list-failures
  3262. List store items corresponding to cached build failures.
  3263. This prints nothing unless the daemon was started with
  3264. @option{--cache-failures} (@pxref{Invoking guix-daemon,
  3265. @option{--cache-failures}}).
  3266. @item --list-roots
  3267. List the GC roots owned by the user; when run as root, list @emph{all} the GC
  3268. roots.
  3269. @item --list-busy
  3270. List store items in use by currently running processes. These store
  3271. items are effectively considered GC roots: they cannot be deleted.
  3272. @item --clear-failures
  3273. Remove the specified store items from the failed-build cache.
  3274. Again, this option only makes sense when the daemon is started with
  3275. @option{--cache-failures}. Otherwise, it does nothing.
  3276. @item --list-dead
  3277. Show the list of dead files and directories still present in the
  3278. store---i.e., files and directories no longer reachable from any root.
  3279. @item --list-live
  3280. Show the list of live store files and directories.
  3281. @end table
  3282. In addition, the references among existing store files can be queried:
  3283. @table @code
  3284. @item --references
  3285. @itemx --referrers
  3286. @cindex package dependencies
  3287. List the references (respectively, the referrers) of store files given
  3288. as arguments.
  3289. @item --requisites
  3290. @itemx -R
  3291. @cindex closure
  3292. List the requisites of the store files passed as arguments. Requisites
  3293. include the store files themselves, their references, and the references
  3294. of these, recursively. In other words, the returned list is the
  3295. @dfn{transitive closure} of the store files.
  3296. @xref{Invoking guix size}, for a tool to profile the size of the closure
  3297. of an element. @xref{Invoking guix graph}, for a tool to visualize
  3298. the graph of references.
  3299. @item --derivers
  3300. @cindex derivation
  3301. Return the derivation(s) leading to the given store items
  3302. (@pxref{Derivations}).
  3303. For example, this command:
  3304. @example
  3305. guix gc --derivers `guix package -I ^emacs$ | cut -f4`
  3306. @end example
  3307. @noindent
  3308. returns the @file{.drv} file(s) leading to the @code{emacs} package
  3309. installed in your profile.
  3310. Note that there may be zero matching @file{.drv} files, for instance
  3311. because these files have been garbage-collected. There can also be more
  3312. than one matching @file{.drv} due to fixed-output derivations.
  3313. @end table
  3314. Lastly, the following options allow you to check the integrity of the
  3315. store and to control disk usage.
  3316. @table @option
  3317. @item --verify[=@var{options}]
  3318. @cindex integrity, of the store
  3319. @cindex integrity checking
  3320. Verify the integrity of the store.
  3321. By default, make sure that all the store items marked as valid in the
  3322. database of the daemon actually exist in @file{/gnu/store}.
  3323. When provided, @var{options} must be a comma-separated list containing one
  3324. or more of @code{contents} and @code{repair}.
  3325. When passing @option{--verify=contents}, the daemon computes the
  3326. content hash of each store item and compares it against its hash in the
  3327. database. Hash mismatches are reported as data corruptions. Because it
  3328. traverses @emph{all the files in the store}, this command can take a
  3329. long time, especially on systems with a slow disk drive.
  3330. @cindex repairing the store
  3331. @cindex corruption, recovering from
  3332. Using @option{--verify=repair} or @option{--verify=contents,repair}
  3333. causes the daemon to try to repair corrupt store items by fetching
  3334. substitutes for them (@pxref{Substitutes}). Because repairing is not
  3335. atomic, and thus potentially dangerous, it is available only to the
  3336. system administrator. A lightweight alternative, when you know exactly
  3337. which items in the store are corrupt, is @command{guix build --repair}
  3338. (@pxref{Invoking guix build}).
  3339. @item --optimize
  3340. @cindex deduplication
  3341. Optimize the store by hard-linking identical files---this is
  3342. @dfn{deduplication}.
  3343. The daemon performs deduplication after each successful build or archive
  3344. import, unless it was started with @option{--disable-deduplication}
  3345. (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
  3346. this option is primarily useful when the daemon was running with
  3347. @option{--disable-deduplication}.
  3348. @end table
  3349. @node Invoking guix pull
  3350. @section Invoking @command{guix pull}
  3351. @cindex upgrading Guix
  3352. @cindex updating Guix
  3353. @cindex @command{guix pull}
  3354. @cindex pull
  3355. @cindex security, @command{guix pull}
  3356. @cindex authenticity, of code obtained with @command{guix pull}
  3357. Packages are installed or upgraded to the latest version available in
  3358. the distribution currently available on your local machine. To update
  3359. that distribution, along with the Guix tools, you must run @command{guix
  3360. pull}: the command downloads the latest Guix source code and package
  3361. descriptions, and deploys it. Source code is downloaded from a
  3362. @uref{https://git-scm.com, Git} repository, by default the official
  3363. GNU@tie{}Guix repository, though this can be customized. @command{guix
  3364. pull} ensures that the code it downloads is @emph{authentic} by
  3365. verifying that commits are signed by Guix developers.
  3366. Specifically, @command{guix pull} downloads code from the @dfn{channels}
  3367. (@pxref{Channels}) specified by one of the followings, in this order:
  3368. @enumerate
  3369. @item
  3370. the @option{--channels} option;
  3371. @item
  3372. the user's @file{~/.config/guix/channels.scm} file;
  3373. @item
  3374. the system-wide @file{/etc/guix/channels.scm} file;
  3375. @item
  3376. the built-in default channels specified in the @code{%default-channels}
  3377. variable.
  3378. @end enumerate
  3379. On completion, @command{guix package} will use packages and package
  3380. versions from this just-retrieved copy of Guix. Not only that, but all
  3381. the Guix commands and Scheme modules will also be taken from that latest
  3382. version. New @command{guix} sub-commands added by the update also
  3383. become available.
  3384. Any user can update their Guix copy using @command{guix pull}, and the
  3385. effect is limited to the user who ran @command{guix pull}. For
  3386. instance, when user @code{root} runs @command{guix pull}, this has no
  3387. effect on the version of Guix that user @code{alice} sees, and vice
  3388. versa.
  3389. The result of running @command{guix pull} is a @dfn{profile} available
  3390. under @file{~/.config/guix/current} containing the latest Guix. Thus,
  3391. make sure to add it to the beginning of your search path so that you use
  3392. the latest version, and similarly for the Info manual
  3393. (@pxref{Documentation}):
  3394. @example
  3395. export PATH="$HOME/.config/guix/current/bin:$PATH"
  3396. export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
  3397. @end example
  3398. The @option{--list-generations} or @option{-l} option lists past generations
  3399. produced by @command{guix pull}, along with details about their provenance:
  3400. @example
  3401. $ guix pull -l
  3402. Generation 1 Jun 10 2018 00:18:18
  3403. guix 65956ad
  3404. repository URL: https://git.savannah.gnu.org/git/guix.git
  3405. branch: origin/master
  3406. commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
  3407. Generation 2 Jun 11 2018 11:02:49
  3408. guix e0cc7f6
  3409. repository URL: https://git.savannah.gnu.org/git/guix.git
  3410. branch: origin/master
  3411. commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
  3412. 2 new packages: keepalived, libnfnetlink
  3413. 6 packages upgraded: emacs-nix-mode@@2.0.4,
  3414. guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
  3415. heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
  3416. Generation 3 Jun 13 2018 23:31:07 (current)
  3417. guix 844cc1c
  3418. repository URL: https://git.savannah.gnu.org/git/guix.git
  3419. branch: origin/master
  3420. commit: 844cc1c8f394f03b404c5bb3aee086922373490c
  3421. 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
  3422. 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
  3423. @end example
  3424. @xref{Invoking guix describe, @command{guix describe}}, for other ways to
  3425. describe the current status of Guix.
  3426. This @code{~/.config/guix/current} profile works exactly like the profiles
  3427. created by @command{guix package} (@pxref{Invoking guix package}). That
  3428. is, you can list generations, roll back to the previous
  3429. generation---i.e., the previous Guix---and so on:
  3430. @example
  3431. $ guix pull --roll-back
  3432. switched from generation 3 to 2
  3433. $ guix pull --delete-generations=1
  3434. deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
  3435. @end example
  3436. You can also use @command{guix package} (@pxref{Invoking guix package})
  3437. to manage the profile by naming it explicitly:
  3438. @example
  3439. $ guix package -p ~/.config/guix/current --roll-back
  3440. switched from generation 3 to 2
  3441. $ guix package -p ~/.config/guix/current --delete-generations=1
  3442. deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
  3443. @end example
  3444. The @command{guix pull} command is usually invoked with no arguments,
  3445. but it supports the following options:
  3446. @table @code
  3447. @item --url=@var{url}
  3448. @itemx --commit=@var{commit}
  3449. @itemx --branch=@var{branch}
  3450. Download code for the @code{guix} channel from the specified @var{url}, at the
  3451. given @var{commit} (a valid Git commit ID represented as a hexadecimal
  3452. string), or @var{branch}.
  3453. @cindex @file{channels.scm}, configuration file
  3454. @cindex configuration file for channels
  3455. These options are provided for convenience, but you can also specify your
  3456. configuration in the @file{~/.config/guix/channels.scm} file or using the
  3457. @option{--channels} option (see below).
  3458. @item --channels=@var{file}
  3459. @itemx -C @var{file}
  3460. Read the list of channels from @var{file} instead of
  3461. @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
  3462. @var{file} must contain Scheme code that
  3463. evaluates to a list of channel objects. @xref{Channels}, for more
  3464. information.
  3465. @cindex channel news
  3466. @item --news
  3467. @itemx -N
  3468. Display the list of packages added or upgraded since the previous
  3469. generation, as well as, occasionally, news written by channel authors
  3470. for their users (@pxref{Channels, Writing Channel News}).
  3471. The package information is the same as displayed upon @command{guix
  3472. pull} completion, but without ellipses; it is also similar to the output
  3473. of @command{guix pull -l} for the last generation (see below).
  3474. @item --list-generations[=@var{pattern}]
  3475. @itemx -l [@var{pattern}]
  3476. List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
  3477. is provided, the subset of generations that match @var{pattern}.
  3478. The syntax of @var{pattern} is the same as with @code{guix package
  3479. --list-generations} (@pxref{Invoking guix package}).
  3480. @item --roll-back
  3481. @cindex rolling back
  3482. @cindex undoing transactions
  3483. @cindex transactions, undoing
  3484. Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
  3485. undo the last transaction.
  3486. @item --switch-generation=@var{pattern}
  3487. @itemx -S @var{pattern}
  3488. @cindex generations
  3489. Switch to a particular generation defined by @var{pattern}.
  3490. @var{pattern} may be either a generation number or a number prefixed
  3491. with ``+'' or ``-''. The latter means: move forward/backward by a
  3492. specified number of generations. For example, if you want to return to
  3493. the latest generation after @option{--roll-back}, use
  3494. @option{--switch-generation=+1}.
  3495. @item --delete-generations[=@var{pattern}]
  3496. @itemx -d [@var{pattern}]
  3497. When @var{pattern} is omitted, delete all generations except the current
  3498. one.
  3499. This command accepts the same patterns as @option{--list-generations}.
  3500. When @var{pattern} is specified, delete the matching generations. When
  3501. @var{pattern} specifies a duration, generations @emph{older} than the
  3502. specified duration match. For instance, @option{--delete-generations=1m}
  3503. deletes generations that are more than one month old.
  3504. If the current generation matches, it is @emph{not} deleted.
  3505. Note that deleting generations prevents rolling back to them.
  3506. Consequently, this command must be used with care.
  3507. @xref{Invoking guix describe}, for a way to display information about the
  3508. current generation only.
  3509. @item --profile=@var{profile}
  3510. @itemx -p @var{profile}
  3511. Use @var{profile} instead of @file{~/.config/guix/current}.
  3512. @item --dry-run
  3513. @itemx -n
  3514. Show which channel commit(s) would be used and what would be built or
  3515. substituted but do not actually do it.
  3516. @item --allow-downgrades
  3517. Allow pulling older or unrelated revisions of channels than those
  3518. currently in use.
  3519. @cindex downgrade attacks, protection against
  3520. By default, @command{guix pull} protects against so-called ``downgrade
  3521. attacks'' whereby the Git repository of a channel would be reset to an
  3522. earlier or unrelated revision of itself, potentially leading you to
  3523. install older, known-vulnerable versions of software packages.
  3524. @quotation Note
  3525. Make sure you understand its security implications before using
  3526. @option{--allow-downgrades}.
  3527. @end quotation
  3528. @item --disable-authentication
  3529. Allow pulling channel code without authenticating it.
  3530. @cindex authentication, of channel code
  3531. By default, @command{guix pull} authenticates code downloaded from
  3532. channels by verifying that its commits are signed by authorized
  3533. developers, and raises an error if this is not the case. This option
  3534. instructs it to not perform any such verification.
  3535. @quotation Note
  3536. Make sure you understand its security implications before using
  3537. @option{--disable-authentication}.
  3538. @end quotation
  3539. @item --system=@var{system}
  3540. @itemx -s @var{system}
  3541. Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
  3542. the system type of the build host.
  3543. @item --bootstrap
  3544. Use the bootstrap Guile to build the latest Guix. This option is only
  3545. useful to Guix developers.
  3546. @end table
  3547. The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
  3548. repository and branch to pull from, as well as @emph{additional} repositories
  3549. containing package modules that should be deployed. @xref{Channels}, for more
  3550. information.
  3551. In addition, @command{guix pull} supports all the common build options
  3552. (@pxref{Common Build Options}).
  3553. @node Invoking guix time-machine
  3554. @section Invoking @command{guix time-machine}
  3555. @cindex @command{guix time-machine}
  3556. @cindex pinning, channels
  3557. @cindex replicating Guix
  3558. @cindex reproducibility, of Guix
  3559. The @command{guix time-machine} command provides access to other
  3560. revisions of Guix, for example to install older versions of packages,
  3561. or to reproduce a computation in an identical environment. The revision
  3562. of Guix to be used is defined by a commit or by a channel
  3563. description file created by @command{guix describe}
  3564. (@pxref{Invoking guix describe}).
  3565. The general syntax is:
  3566. @example
  3567. guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
  3568. @end example
  3569. where @var{command} and @var{arg}@dots{} are passed unmodified to the
  3570. @command{guix} command of the specified revision. The @var{options} that define
  3571. this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
  3572. @table @code
  3573. @item --url=@var{url}
  3574. @itemx --commit=@var{commit}
  3575. @itemx --branch=@var{branch}
  3576. Use the @code{guix} channel from the specified @var{url}, at the
  3577. given @var{commit} (a valid Git commit ID represented as a hexadecimal
  3578. string), or @var{branch}.
  3579. @item --channels=@var{file}
  3580. @itemx -C @var{file}
  3581. Read the list of channels from @var{file}. @var{file} must contain
  3582. Scheme code that evaluates to a list of channel objects.
  3583. @xref{Channels} for more information.
  3584. @end table
  3585. As for @command{guix pull}, the absence of any options means that the
  3586. latest commit on the master branch will be used. The command
  3587. @example
  3588. guix time-machine -- build hello
  3589. @end example
  3590. will thus build the package @code{hello} as defined in the master branch,
  3591. which is in general a newer revision of Guix than you have installed.
  3592. Time travel works in both directions!
  3593. Note that @command{guix time-machine} can trigger builds of channels and
  3594. their dependencies, and these are controlled by the standard build
  3595. options (@pxref{Common Build Options}).
  3596. @node Inferiors
  3597. @section Inferiors
  3598. @c TODO: Remove this once we're more confident about API stability.
  3599. @quotation Note
  3600. The functionality described here is a ``technology preview'' as of version
  3601. @value{VERSION}. As such, the interface is subject to change.
  3602. @end quotation
  3603. @cindex inferiors
  3604. @cindex composition of Guix revisions
  3605. Sometimes you might need to mix packages from the revision of Guix you're
  3606. currently running with packages available in a different revision of Guix.
  3607. Guix @dfn{inferiors} allow you to achieve that by composing different Guix
  3608. revisions in arbitrary ways.
  3609. @cindex inferior packages
  3610. Technically, an ``inferior'' is essentially a separate Guix process connected
  3611. to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
  3612. @code{(guix inferior)} module allows you to create inferiors and to
  3613. communicate with them. It also provides a high-level interface to browse and
  3614. manipulate the packages that an inferior provides---@dfn{inferior packages}.
  3615. When combined with channels (@pxref{Channels}), inferiors provide a simple way
  3616. to interact with a separate revision of Guix. For example, let's assume you
  3617. want to install in your profile the current @code{guile} package, along with
  3618. the @code{guile-json} as it existed in an older revision of Guix---perhaps
  3619. because the newer @code{guile-json} has an incompatible API and you want to
  3620. run your code against the old API@. To do that, you could write a manifest for
  3621. use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
  3622. manifest, you would create an inferior for that old Guix revision you care
  3623. about, and you would look up the @code{guile-json} package in the inferior:
  3624. @lisp
  3625. (use-modules (guix inferior) (guix channels)
  3626. (srfi srfi-1)) ;for 'first'
  3627. (define channels
  3628. ;; This is the old revision from which we want to
  3629. ;; extract guile-json.
  3630. (list (channel
  3631. (name 'guix)
  3632. (url "https://git.savannah.gnu.org/git/guix.git")
  3633. (commit
  3634. "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
  3635. (define inferior
  3636. ;; An inferior representing the above revision.
  3637. (inferior-for-channels channels))
  3638. ;; Now create a manifest with the current "guile" package
  3639. ;; and the old "guile-json" package.
  3640. (packages->manifest
  3641. (list (first (lookup-inferior-packages inferior "guile-json"))
  3642. (specification->package "guile")))
  3643. @end lisp
  3644. On its first run, @command{guix package --manifest} might have to build the
  3645. channel you specified before it can create the inferior; subsequent runs will
  3646. be much faster because the Guix revision will be cached.
  3647. The @code{(guix inferior)} module provides the following procedures to open an
  3648. inferior:
  3649. @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
  3650. [#:cache-directory] [#:ttl]
  3651. Return an inferior for @var{channels}, a list of channels. Use the cache at
  3652. @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
  3653. This procedure opens a new connection to the build daemon.
  3654. As a side effect, this procedure may build or substitute binaries for
  3655. @var{channels}, which can take time.
  3656. @end deffn
  3657. @deffn {Scheme Procedure} open-inferior @var{directory} @
  3658. [#:command "bin/guix"]
  3659. Open the inferior Guix in @var{directory}, running
  3660. @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
  3661. the inferior could not be launched.
  3662. @end deffn
  3663. @cindex inferior packages
  3664. The procedures listed below allow you to obtain and manipulate inferior
  3665. packages.
  3666. @deffn {Scheme Procedure} inferior-packages @var{inferior}
  3667. Return the list of packages known to @var{inferior}.
  3668. @end deffn
  3669. @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
  3670. [@var{version}]
  3671. Return the sorted list of inferior packages matching @var{name} in
  3672. @var{inferior}, with highest version numbers first. If @var{version} is true,
  3673. return only packages with a version number prefixed by @var{version}.
  3674. @end deffn
  3675. @deffn {Scheme Procedure} inferior-package? @var{obj}
  3676. Return true if @var{obj} is an inferior package.
  3677. @end deffn
  3678. @deffn {Scheme Procedure} inferior-package-name @var{package}
  3679. @deffnx {Scheme Procedure} inferior-package-version @var{package}
  3680. @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
  3681. @deffnx {Scheme Procedure} inferior-package-description @var{package}
  3682. @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
  3683. @deffnx {Scheme Procedure} inferior-package-location @var{package}
  3684. @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
  3685. @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
  3686. @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
  3687. @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
  3688. @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
  3689. @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
  3690. @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
  3691. These procedures are the counterpart of package record accessors
  3692. (@pxref{package Reference}). Most of them work by querying the inferior
  3693. @var{package} comes from, so the inferior must still be live when you call
  3694. these procedures.
  3695. @end deffn
  3696. Inferior packages can be used transparently like any other package or
  3697. file-like object in G-expressions (@pxref{G-Expressions}). They are also
  3698. transparently handled by the @code{packages->manifest} procedure, which is
  3699. commonly use in manifests (@pxref{Invoking guix package, the
  3700. @option{--manifest} option of @command{guix package}}). Thus you can insert
  3701. an inferior package pretty much anywhere you would insert a regular package:
  3702. in manifests, in the @code{packages} field of your @code{operating-system}
  3703. declaration, and so on.
  3704. @node Invoking guix describe
  3705. @section Invoking @command{guix describe}
  3706. @cindex reproducibility
  3707. @cindex replicating Guix
  3708. Often you may want to answer questions like: ``Which revision of Guix am I
  3709. using?'' or ``Which channels am I using?'' This is useful information in many
  3710. situations: if you want to @emph{replicate} an environment on a different
  3711. machine or user account, if you want to report a bug or to determine what
  3712. change in the channels you are using caused it, or if you want to record your
  3713. system state for reproducibility purposes. The @command{guix describe}
  3714. command answers these questions.
  3715. When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
  3716. displays the channel(s) that it was built from, including their repository URL
  3717. and commit IDs (@pxref{Channels}):
  3718. @example
  3719. $ guix describe
  3720. Generation 10 Sep 03 2018 17:32:44 (current)
  3721. guix e0fa68c
  3722. repository URL: https://git.savannah.gnu.org/git/guix.git
  3723. branch: master
  3724. commit: e0fa68c7718fffd33d81af415279d6ddb518f727
  3725. @end example
  3726. If you're familiar with the Git version control system, this is similar in
  3727. spirit to @command{git describe}; the output is also similar to that of
  3728. @command{guix pull --list-generations}, but limited to the current generation
  3729. (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
  3730. the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
  3731. information is all it takes to describe the revision of Guix you're using, and
  3732. also to replicate it.
  3733. To make it easier to replicate Guix, @command{guix describe} can also be asked
  3734. to return a list of channels instead of the human-readable description above:
  3735. @example
  3736. $ guix describe -f channels
  3737. (list (channel
  3738. (name 'guix)
  3739. (url "https://git.savannah.gnu.org/git/guix.git")
  3740. (commit
  3741. "e0fa68c7718fffd33d81af415279d6ddb518f727")
  3742. (introduction
  3743. (make-channel-introduction
  3744. "9edb3f66fd807b096b48283debdcddccfea34bad"
  3745. (openpgp-fingerprint
  3746. "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
  3747. @end example
  3748. @noindent
  3749. You can save this to a file and feed it to @command{guix pull -C} on some
  3750. other machine or at a later point in time, which will instantiate @emph{this
  3751. exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
  3752. From there on, since you're able to deploy the same revision of Guix, you can
  3753. just as well @emph{replicate a complete software environment}. We humbly
  3754. think that this is @emph{awesome}, and we hope you'll like it too!
  3755. The details of the options supported by @command{guix describe} are as
  3756. follows:
  3757. @table @code
  3758. @item --format=@var{format}
  3759. @itemx -f @var{format}
  3760. Produce output in the specified @var{format}, one of:
  3761. @table @code
  3762. @item human
  3763. produce human-readable output;
  3764. @item channels
  3765. produce a list of channel specifications that can be passed to @command{guix
  3766. pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
  3767. guix pull});
  3768. @item channels-sans-intro
  3769. like @code{channels}, but omit the @code{introduction} field; use it to
  3770. produce a channel specification suitable for Guix version 1.1.0 or
  3771. earlier---the @code{introduction} field has to do with channel
  3772. authentication (@pxref{Channels, Channel Authentication}) and is not
  3773. supported by these older versions;
  3774. @item json
  3775. @cindex JSON
  3776. produce a list of channel specifications in JSON format;
  3777. @item recutils
  3778. produce a list of channel specifications in Recutils format.
  3779. @end table
  3780. @item --list-formats
  3781. Display available formats for @option{--format} option.
  3782. @item --profile=@var{profile}
  3783. @itemx -p @var{profile}
  3784. Display information about @var{profile}.
  3785. @end table
  3786. @node Invoking guix archive
  3787. @section Invoking @command{guix archive}
  3788. @cindex @command{guix archive}
  3789. @cindex archive
  3790. The @command{guix archive} command allows users to @dfn{export} files
  3791. from the store into a single archive, and to later @dfn{import} them on
  3792. a machine that runs Guix.
  3793. In particular, it allows store files to be transferred from one machine
  3794. to the store on another machine.
  3795. @quotation Note
  3796. If you're looking for a way to produce archives in a format suitable for
  3797. tools other than Guix, @pxref{Invoking guix pack}.
  3798. @end quotation
  3799. @cindex exporting store items
  3800. To export store files as an archive to standard output, run:
  3801. @example
  3802. guix archive --export @var{options} @var{specifications}...
  3803. @end example
  3804. @var{specifications} may be either store file names or package
  3805. specifications, as for @command{guix package} (@pxref{Invoking guix
  3806. package}). For instance, the following command creates an archive
  3807. containing the @code{gui} output of the @code{git} package and the main
  3808. output of @code{emacs}:
  3809. @example
  3810. guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
  3811. @end example
  3812. If the specified packages are not built yet, @command{guix archive}
  3813. automatically builds them. The build process may be controlled with the
  3814. common build options (@pxref{Common Build Options}).
  3815. To transfer the @code{emacs} package to a machine connected over SSH,
  3816. one would run:
  3817. @example
  3818. guix archive --export -r emacs | ssh the-machine guix archive --import
  3819. @end example
  3820. @noindent
  3821. Similarly, a complete user profile may be transferred from one machine
  3822. to another like this:
  3823. @example
  3824. guix archive --export -r $(readlink -f ~/.guix-profile) | \
  3825. ssh the-machine guix archive --import
  3826. @end example
  3827. @noindent
  3828. However, note that, in both examples, all of @code{emacs} and the
  3829. profile as well as all of their dependencies are transferred (due to
  3830. @option{-r}), regardless of what is already available in the store on
  3831. the target machine. The @option{--missing} option can help figure out
  3832. which items are missing from the target store. The @command{guix copy}
  3833. command simplifies and optimizes this whole process, so this is probably
  3834. what you should use in this case (@pxref{Invoking guix copy}).
  3835. @cindex nar, archive format
  3836. @cindex normalized archive (nar)
  3837. @cindex nar bundle, archive format
  3838. Each store item is written in the @dfn{normalized archive} or @dfn{nar}
  3839. format (described below), and the output of @command{guix archive
  3840. --export} (and input of @command{guix archive --import}) is a @dfn{nar
  3841. bundle}.
  3842. The nar format is
  3843. comparable in spirit to `tar', but with differences
  3844. that make it more appropriate for our purposes. First, rather than
  3845. recording all Unix metadata for each file, the nar format only mentions
  3846. the file type (regular, directory, or symbolic link); Unix permissions
  3847. and owner/group are dismissed. Second, the order in which directory
  3848. entries are stored always follows the order of file names according to
  3849. the C locale collation order. This makes archive production fully
  3850. deterministic.
  3851. That nar bundle format is essentially the concatenation of zero or more
  3852. nars along with metadata for each store item it contains: its file name,
  3853. references, corresponding derivation, and a digital signature.
  3854. When exporting, the daemon digitally signs the contents of the archive,
  3855. and that digital signature is appended. When importing, the daemon
  3856. verifies the signature and rejects the import in case of an invalid
  3857. signature or if the signing key is not authorized.
  3858. @c FIXME: Add xref to daemon doc about signatures.
  3859. The main options are:
  3860. @table @code
  3861. @item --export
  3862. Export the specified store files or packages (see below). Write the
  3863. resulting archive to the standard output.
  3864. Dependencies are @emph{not} included in the output, unless
  3865. @option{--recursive} is passed.
  3866. @item -r
  3867. @itemx --recursive
  3868. When combined with @option{--export}, this instructs @command{guix archive}
  3869. to include dependencies of the given items in the archive. Thus, the
  3870. resulting archive is self-contained: it contains the closure of the
  3871. exported store items.
  3872. @item --import
  3873. Read an archive from the standard input, and import the files listed
  3874. therein into the store. Abort if the archive has an invalid digital
  3875. signature, or if it is signed by a public key not among the authorized
  3876. keys (see @option{--authorize} below).
  3877. @item --missing
  3878. Read a list of store file names from the standard input, one per line,
  3879. and write on the standard output the subset of these files missing from
  3880. the store.
  3881. @item --generate-key[=@var{parameters}]
  3882. @cindex signing, archives
  3883. Generate a new key pair for the daemon. This is a prerequisite before
  3884. archives can be exported with @option{--export}. This
  3885. operation is usually instantaneous but it can take time if the system's
  3886. entropy pool needs to be refilled. On Guix System,
  3887. @code{guix-service-type} takes care of generating this key pair the
  3888. first boot.
  3889. The generated key pair is typically stored under @file{/etc/guix}, in
  3890. @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
  3891. key, which must be kept secret). When @var{parameters} is omitted,
  3892. an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
  3893. versions before 1.6.0, it is a 4096-bit RSA key.
  3894. Alternatively, @var{parameters} can specify
  3895. @code{genkey} parameters suitable for Libgcrypt (@pxref{General
  3896. public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
  3897. Libgcrypt Reference Manual}).
  3898. @item --authorize
  3899. @cindex authorizing, archives
  3900. Authorize imports signed by the public key passed on standard input.
  3901. The public key must be in ``s-expression advanced format''---i.e., the
  3902. same format as the @file{signing-key.pub} file.
  3903. The list of authorized keys is kept in the human-editable file
  3904. @file{/etc/guix/acl}. The file contains
  3905. @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
  3906. s-expressions''} and is structured as an access-control list in the
  3907. @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
  3908. (SPKI)}.
  3909. @item --extract=@var{directory}
  3910. @itemx -x @var{directory}
  3911. Read a single-item archive as served by substitute servers
  3912. (@pxref{Substitutes}) and extract it to @var{directory}. This is a
  3913. low-level operation needed in only very narrow use cases; see below.
  3914. For example, the following command extracts the substitute for Emacs
  3915. served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
  3916. @example
  3917. $ wget -O - \
  3918. https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
  3919. | gunzip | guix archive -x /tmp/emacs
  3920. @end example
  3921. Single-item archives are different from multiple-item archives produced
  3922. by @command{guix archive --export}; they contain a single store item,
  3923. and they do @emph{not} embed a signature. Thus this operation does
  3924. @emph{no} signature verification and its output should be considered
  3925. unsafe.
  3926. The primary purpose of this operation is to facilitate inspection of
  3927. archive contents coming from possibly untrusted substitute servers
  3928. (@pxref{Invoking guix challenge}).
  3929. @item --list
  3930. @itemx -t
  3931. Read a single-item archive as served by substitute servers
  3932. (@pxref{Substitutes}) and print the list of files it contains, as in
  3933. this example:
  3934. @example
  3935. $ wget -O - \
  3936. https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
  3937. | lzip -d | guix archive -t
  3938. @end example
  3939. @end table
  3940. @c *********************************************************************
  3941. @node Channels
  3942. @chapter Channels
  3943. @cindex channels
  3944. @cindex @file{channels.scm}, configuration file
  3945. @cindex configuration file for channels
  3946. @cindex @command{guix pull}, configuration file
  3947. @cindex configuration of @command{guix pull}
  3948. Guix and its package collection are updated by running @command{guix pull}
  3949. (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
  3950. deploys Guix itself from the official GNU@tie{}Guix repository. This can be
  3951. customized by defining @dfn{channels} in the
  3952. @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
  3953. of a Git repository to be deployed, and @command{guix pull} can be instructed
  3954. to pull from one or more channels. In other words, channels can be used
  3955. to @emph{customize} and to @emph{extend} Guix, as we will see below.
  3956. Guix is able to take into account security concerns and deal with authenticated
  3957. updates.
  3958. @menu
  3959. * Specifying Additional Channels:: Extending the package collection.
  3960. * Using a Custom Guix Channel:: Using a customized Guix.
  3961. * Replicating Guix:: Running the @emph{exact same} Guix.
  3962. * Channel Authentication:: How Guix verifies what it fetches.
  3963. * Creating a Channel:: How to write your custom channel.
  3964. * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
  3965. * Declaring Channel Dependencies:: How to depend on other channels.
  3966. * Specifying Channel Authorizations:: Defining channel authors authorizations.
  3967. * Primary URL:: Distinguishing mirror to original.
  3968. * Writing Channel News:: Communicating information to channel's users.
  3969. @end menu
  3970. @node Specifying Additional Channels
  3971. @section Specifying Additional Channels
  3972. @cindex extending the package collection (channels)
  3973. @cindex variant packages (channels)
  3974. You can specify @emph{additional channels} to pull from. To use a channel, write
  3975. @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
  3976. @emph{in addition} to the default Guix channel(s):
  3977. @vindex %default-channels
  3978. @lisp
  3979. ;; Add variant packages to those Guix provides.
  3980. (cons (channel
  3981. (name 'variant-packages)
  3982. (url "https://example.org/variant-packages.git"))
  3983. %default-channels)
  3984. @end lisp
  3985. @noindent
  3986. Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
  3987. add a channel the list of channels that the variable @code{%default-channels}
  3988. is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
  3989. Manual}). With this file in place, @command{guix pull} builds not only Guix
  3990. but also the package modules from your own repository. The result in
  3991. @file{~/.config/guix/current} is the union of Guix with your own package
  3992. modules:
  3993. @example
  3994. $ guix pull --list-generations
  3995. @dots{}
  3996. Generation 19 Aug 27 2018 16:20:48
  3997. guix d894ab8
  3998. repository URL: https://git.savannah.gnu.org/git/guix.git
  3999. branch: master
  4000. commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
  4001. variant-packages dd3df5e
  4002. repository URL: https://example.org/variant-packages.git
  4003. branch: master
  4004. commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
  4005. 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
  4006. 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
  4007. @end example
  4008. @noindent
  4009. The output of @command{guix pull} above shows that Generation@tie{}19 includes
  4010. both Guix and packages from the @code{variant-personal-packages} channel. Among
  4011. the new and upgraded packages that are listed, some like @code{variant-gimp} and
  4012. @code{variant-emacs-with-cool-features} might come from
  4013. @code{variant-packages}, while others come from the Guix default channel.
  4014. @node Using a Custom Guix Channel
  4015. @section Using a Custom Guix Channel
  4016. The channel called @code{guix} specifies where Guix itself---its command-line
  4017. tools as well as its package collection---should be downloaded. For instance,
  4018. suppose you want to update from another copy of the Guix repository at
  4019. @code{example.org}, and specifically the @code{super-hacks} branch, you can
  4020. write in @code{~/.config/guix/channels.scm} this specification:
  4021. @lisp
  4022. ;; Tell 'guix pull' to use another repo.
  4023. (list (channel
  4024. (name 'guix)
  4025. (url "https://example.org/another-guix.git")
  4026. (branch "super-hacks")))
  4027. @end lisp
  4028. @noindent
  4029. From there on, @command{guix pull} will fetch code from the @code{super-hacks}
  4030. branch of the repository at @code{example.org}. The authentication concern is
  4031. addressed below ((@pxref{Channel Authentication}).
  4032. @node Replicating Guix
  4033. @section Replicating Guix
  4034. @cindex pinning, channels
  4035. @cindex replicating Guix
  4036. @cindex reproducibility, of Guix
  4037. The @command{guix pull --list-generations} output above shows precisely which
  4038. commits were used to build this instance of Guix. We can thus replicate it,
  4039. say, on another machine, by providing a channel specification in
  4040. @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
  4041. @lisp
  4042. ;; Deploy specific commits of my channels of interest.
  4043. (list (channel
  4044. (name 'guix)
  4045. (url "https://git.savannah.gnu.org/git/guix.git")
  4046. (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
  4047. (channel
  4048. (name 'variant-packages)
  4049. (url "https://example.org/variant-packages.git")
  4050. (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
  4051. @end lisp
  4052. The @command{guix describe --format=channels} command can even generate this
  4053. list of channels directly (@pxref{Invoking guix describe}). The resulting
  4054. file can be used with the -C options of @command{guix pull}
  4055. (@pxref{Invoking guix pull}) or @command{guix time-machine}
  4056. (@pxref{Invoking guix time-machine}).
  4057. At this point the two machines run the @emph{exact same Guix}, with access to
  4058. the @emph{exact same packages}. The output of @command{guix build gimp} on
  4059. one machine will be exactly the same, bit for bit, as the output of the same
  4060. command on the other machine. It also means both machines have access to all
  4061. the source code of Guix and, transitively, to all the source code of every
  4062. package it defines.
  4063. This gives you super powers, allowing you to track the provenance of binary
  4064. artifacts with very fine grain, and to reproduce software environments at
  4065. will---some sort of ``meta reproducibility'' capabilities, if you will.
  4066. @xref{Inferiors}, for another way to take advantage of these super powers.
  4067. @node Channel Authentication
  4068. @section Channel Authentication
  4069. @anchor{channel-authentication}
  4070. @cindex authentication, of channel code
  4071. The @command{guix pull} and @command{guix time-machine} commands
  4072. @dfn{authenticate} the code retrieved from channels: they make sure each
  4073. commit that is fetched is signed by an authorized developer. The goal
  4074. is to protect from unauthorized modifications to the channel that would
  4075. lead users to run malicious code.
  4076. As a user, you must provide a @dfn{channel introduction} in your
  4077. channels file so that Guix knows how to authenticate its first commit.
  4078. A channel specification, including its introduction, looks something
  4079. along these lines:
  4080. @lisp
  4081. (channel
  4082. (name 'some-channel)
  4083. (url "https://example.org/some-channel.git")
  4084. (introduction
  4085. (make-channel-introduction
  4086. "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
  4087. (openpgp-fingerprint
  4088. "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
  4089. @end lisp
  4090. The specification above shows the name and URL of the channel. The call
  4091. to @code{make-channel-introduction} above specifies that authentication
  4092. of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
  4093. by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
  4094. For the main channel, called @code{guix}, you automatically get that
  4095. information from your Guix installation. For other channels, include
  4096. the channel introduction provided by the channel authors in your
  4097. @file{channels.scm} file. Make sure you retrieve the channel
  4098. introduction from a trusted source since that is the root of your trust.
  4099. If you're curious about the authentication mechanics, read on!
  4100. @node Creating a Channel
  4101. @section Creating a Channel
  4102. @cindex personal packages (channels)
  4103. @cindex channels, for personal packages
  4104. Let's say you have a bunch of custom package variants or personal packages
  4105. that you think would make little sense to contribute to the Guix project, but
  4106. would like to have these packages transparently available to you at the
  4107. command line. You would first write modules containing those package
  4108. definitions (@pxref{Package Modules}), maintain them in a Git repository, and
  4109. then you and anyone else can use it as an additional channel to get packages
  4110. from. Neat, no?
  4111. @c What follows stems from discussions at
  4112. @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
  4113. @c earlier discussions on guix-devel@gnu.org.
  4114. @quotation Warning
  4115. Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
  4116. publish your personal channel to the world, we would like to share a few words
  4117. of caution:
  4118. @itemize
  4119. @item
  4120. Before publishing a channel, please consider contributing your package
  4121. definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
  4122. to free software of all sorts, and packages in Guix proper are readily
  4123. available to all Guix users and benefit from the project's quality assurance
  4124. process.
  4125. @item
  4126. When you maintain package definitions outside Guix, we, Guix developers,
  4127. consider that @emph{the compatibility burden is on you}. Remember that
  4128. package modules and package definitions are just Scheme code that uses various
  4129. programming interfaces (APIs). We want to remain free to change these APIs to
  4130. keep improving Guix, possibly in ways that break your channel. We never
  4131. change APIs gratuitously, but we will @emph{not} commit to freezing APIs
  4132. either.
  4133. @item
  4134. Corollary: if you're using an external channel and that channel breaks, please
  4135. @emph{report the issue to the channel authors}, not to the Guix project.
  4136. @end itemize
  4137. You've been warned! Having said this, we believe external channels are a
  4138. practical way to exert your freedom to augment Guix' package collection and to
  4139. share your improvements, which are basic tenets of
  4140. @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
  4141. email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
  4142. @end quotation
  4143. To create a channel, create a Git repository containing your own package
  4144. modules and make it available. The repository can contain anything, but a
  4145. useful channel will contain Guile modules that export packages. Once you
  4146. start using a channel, Guix will behave as if the root directory of that
  4147. channel's Git repository has been added to the Guile load path (@pxref{Load
  4148. Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
  4149. contains a file at @file{my-packages/my-tools.scm} that defines a Guile
  4150. module, then the module will be available under the name @code{(my-packages
  4151. my-tools)}, and you will be able to use it like any other module
  4152. (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
  4153. As a channel author, consider bundling authentication material with your
  4154. channel so that users can authenticate it. @xref{Channel
  4155. Authentication}, and @ref{Specifying Channel Authorizations}, for info
  4156. on how to do it.
  4157. @node Package Modules in a Sub-directory
  4158. @section Package Modules in a Sub-directory
  4159. @cindex subdirectory, channels
  4160. As a channel author, you may want to keep your channel modules in a
  4161. sub-directory. If your modules are in the sub-directory @file{guix}, you must
  4162. add a meta-data file @file{.guix-channel} that contains:
  4163. @lisp
  4164. (channel
  4165. (version 0)
  4166. (directory "guix"))
  4167. @end lisp
  4168. @node Declaring Channel Dependencies
  4169. @section Declaring Channel Dependencies
  4170. @cindex dependencies, channels
  4171. @cindex meta-data, channels
  4172. Channel authors may decide to augment a package collection provided by other
  4173. channels. They can declare their channel to be dependent on other channels in
  4174. a meta-data file @file{.guix-channel}, which is to be placed in the root of
  4175. the channel repository.
  4176. The meta-data file should contain a simple S-expression like this:
  4177. @lisp
  4178. (channel
  4179. (version 0)
  4180. (dependencies
  4181. (channel
  4182. (name 'some-collection)
  4183. (url "https://example.org/first-collection.git")
  4184. ;; The 'introduction' bit below is optional: you would
  4185. ;; provide it for dependencies that can be authenticated.
  4186. (introduction
  4187. (channel-introduction
  4188. (version 0)
  4189. (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
  4190. (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
  4191. (channel
  4192. (name 'some-other-collection)
  4193. (url "https://example.org/second-collection.git")
  4194. (branch "testing"))))
  4195. @end lisp
  4196. In the above example this channel is declared to depend on two other channels,
  4197. which will both be fetched automatically. The modules provided by the channel
  4198. will be compiled in an environment where the modules of all these declared
  4199. channels are available.
  4200. For the sake of reliability and maintainability, you should avoid dependencies
  4201. on channels that you don't control, and you should aim to keep the number of
  4202. dependencies to a minimum.
  4203. @node Specifying Channel Authorizations
  4204. @section Specifying Channel Authorizations
  4205. @cindex channel authorizations
  4206. @anchor{channel-authorizations}
  4207. As we saw above, Guix ensures the source code it pulls from channels
  4208. comes from authorized developers. As a channel author, you need to
  4209. specify the list of authorized developers in the
  4210. @file{.guix-authorizations} file in the channel's Git repository. The
  4211. authentication rule is simple: each commit must be signed by a key
  4212. listed in the @file{.guix-authorizations} file of its parent
  4213. commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
  4214. (DAG). Each commit can have zero or more parents; ``regular'' commits
  4215. have one parent and merge commits have two parent commits. Read
  4216. @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
  4217. for Computer Scientists}} for a great overview.} The
  4218. @file{.guix-authorizations} file looks like this:
  4219. @lisp
  4220. ;; Example '.guix-authorizations' file.
  4221. (authorizations
  4222. (version 0) ;current file format version
  4223. (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
  4224. (name "alice"))
  4225. ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
  4226. (name "bob"))
  4227. ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
  4228. (name "charlie"))))
  4229. @end lisp
  4230. Each fingerprint is followed by optional key/value pairs, as in the
  4231. example above. Currently these key/value pairs are ignored.
  4232. This authentication rule creates a chicken-and-egg issue: how do we
  4233. authenticate the first commit? Related to that: how do we deal with
  4234. channels whose repository history contains unsigned commits and lack
  4235. @file{.guix-authorizations}? And how do we fork existing channels?
  4236. @cindex channel introduction
  4237. Channel introductions answer these questions by describing the first
  4238. commit of a channel that should be authenticated. The first time a
  4239. channel is fetched with @command{guix pull} or @command{guix
  4240. time-machine}, the command looks up the introductory commit and verifies
  4241. that it is signed by the specified OpenPGP key. From then on, it
  4242. authenticates commits according to the rule above.
  4243. Additionally, your channel must provide all the OpenPGP keys that were
  4244. ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
  4245. files, which can be either binary or ``ASCII-armored''. By default,
  4246. those @file{.key} files are searched for in the branch named
  4247. @code{keyring} but you can specify a different branch name in
  4248. @code{.guix-channel} like so:
  4249. @lisp
  4250. (channel
  4251. (version 0)
  4252. (keyring-reference "my-keyring-branch"))
  4253. @end lisp
  4254. To summarize, as the author of a channel, there are three things you have
  4255. to do to allow users to authenticate your code:
  4256. @enumerate
  4257. @item
  4258. Export the OpenPGP keys of past and present committers with @command{gpg
  4259. --export} and store them in @file{.key} files, by default in a branch
  4260. named @code{keyring} (we recommend making it an @dfn{orphan branch}).
  4261. @item
  4262. Introduce an initial @file{.guix-authorizations} in the channel's
  4263. repository. Do that in a signed commit (@pxref{Commit Access}, for
  4264. information on how to sign Git commits.)
  4265. @item
  4266. Advertise the channel introduction, for instance on your channel's web
  4267. page. The channel introduction, as we saw above, is the commit/key
  4268. pair---i.e., the commit that introduced @file{.guix-authorizations}, and
  4269. the fingerprint of the OpenPGP used to sign it.
  4270. @end enumerate
  4271. Before pushing to your public Git repository, you can run @command{guix
  4272. git-authenticate} to verify that you did sign all the commits you are
  4273. about to push with an authorized key:
  4274. @example
  4275. guix git authenticate @var{commit} @var{signer}
  4276. @end example
  4277. @noindent
  4278. where @var{commit} and @var{signer} are your channel introduction.
  4279. @xref{Invoking guix git authenticate}, for details.
  4280. Publishing a signed channel requires discipline: any mistake, such as an
  4281. unsigned commit or a commit signed by an unauthorized key, will prevent
  4282. users from pulling from your channel---well, that's the whole point of
  4283. authentication! Pay attention to merges in particular: merge commits
  4284. are considered authentic if and only if they are signed by a key present
  4285. in the @file{.guix-authorizations} file of @emph{both} branches.
  4286. @node Primary URL
  4287. @section Primary URL
  4288. @cindex primary URL, channels
  4289. Channel authors can indicate the primary URL of their channel's Git
  4290. repository in the @file{.guix-channel} file, like so:
  4291. @lisp
  4292. (channel
  4293. (version 0)
  4294. (url "https://example.org/guix.git"))
  4295. @end lisp
  4296. This allows @command{guix pull} to determine whether it is pulling code
  4297. from a mirror of the channel; when that is the case, it warns the user
  4298. that the mirror might be stale and displays the primary URL@. That way,
  4299. users cannot be tricked into fetching code from a stale mirror that does
  4300. not receive security updates.
  4301. This feature only makes sense for authenticated repositories, such as
  4302. the official @code{guix} channel, for which @command{guix pull} ensures
  4303. the code it fetches is authentic.
  4304. @node Writing Channel News
  4305. @section Writing Channel News
  4306. @cindex news, for channels
  4307. Channel authors may occasionally want to communicate to their users
  4308. information about important changes in the channel. You'd send them all
  4309. an email, but that's not convenient.
  4310. Instead, channels can provide a @dfn{news file}; when the channel users
  4311. run @command{guix pull}, that news file is automatically read and
  4312. @command{guix pull --news} can display the announcements that correspond
  4313. to the new commits that have been pulled, if any.
  4314. To do that, channel authors must first declare the name of the news file
  4315. in their @file{.guix-channel} file:
  4316. @lisp
  4317. (channel
  4318. (version 0)
  4319. (news-file "etc/news.txt"))
  4320. @end lisp
  4321. The news file itself, @file{etc/news.txt} in this example, must look
  4322. something like this:
  4323. @lisp
  4324. (channel-news
  4325. (version 0)
  4326. (entry (tag "the-bug-fix")
  4327. (title (en "Fixed terrible bug")
  4328. (fr "Oh la la"))
  4329. (body (en "@@emph@{Good news@}! It's fixed!")
  4330. (eo "Certe ĝi pli bone funkcias nun!")))
  4331. (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
  4332. (title (en "Added a great package")
  4333. (ca "Què vol dir guix?"))
  4334. (body (en "Don't miss the @@code@{hello@} package!"))))
  4335. @end lisp
  4336. While the news file is using the Scheme syntax, avoid naming it with a
  4337. @file{.scm} extension or else it will get picked up when building the
  4338. channel and yield an error since it is not a valid module.
  4339. Alternatively, you can move the channel module to a subdirectory and
  4340. store the news file in another directory.
  4341. The file consists of a list of @dfn{news entries}. Each entry is
  4342. associated with a commit or tag: it describes changes made in this
  4343. commit, possibly in preceding commits as well. Users see entries only
  4344. the first time they obtain the commit the entry refers to.
  4345. The @code{title} field should be a one-line summary while @code{body}
  4346. can be arbitrarily long, and both can contain Texinfo markup
  4347. (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
  4348. a list of language tag/message tuples, which allows @command{guix pull}
  4349. to display news in the language that corresponds to the user's locale.
  4350. If you want to translate news using a gettext-based workflow, you can
  4351. extract translatable strings with @command{xgettext} (@pxref{xgettext
  4352. Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
  4353. you write news entries in English first, the command below creates a PO
  4354. file containing the strings to translate:
  4355. @example
  4356. xgettext -o news.po -l scheme -ken etc/news.txt
  4357. @end example
  4358. To sum up, yes, you could use your channel as a blog. But beware, this
  4359. is @emph{not quite} what your users might expect.
  4360. @c *********************************************************************
  4361. @node Development
  4362. @chapter Development
  4363. @cindex software development
  4364. If you are a software developer, Guix provides tools that you should find
  4365. helpful---independently of the language you're developing in. This is what
  4366. this chapter is about.
  4367. The @command{guix environment} command provides a convenient way to set up
  4368. @dfn{development environments} containing all the dependencies and tools
  4369. necessary to work on the software package of your choice. The @command{guix
  4370. pack} command allows you to create @dfn{application bundles} that can be
  4371. easily distributed to users who do not run Guix.
  4372. @menu
  4373. * Invoking guix environment:: Setting up development environments.
  4374. * Invoking guix pack:: Creating software bundles.
  4375. * The GCC toolchain:: Working with languages supported by GCC.
  4376. * Invoking guix git authenticate:: Authenticating Git repositories.
  4377. @end menu
  4378. @node Invoking guix environment
  4379. @section Invoking @command{guix environment}
  4380. @cindex reproducible build environments
  4381. @cindex development environments
  4382. @cindex @command{guix environment}
  4383. @cindex environment, package build environment
  4384. The purpose of @command{guix environment} is to assist hackers in
  4385. creating reproducible development environments without polluting their
  4386. package profile. The @command{guix environment} tool takes one or more
  4387. packages, builds all of their inputs, and creates a shell
  4388. environment to use them.
  4389. The general syntax is:
  4390. @example
  4391. guix environment @var{options} @var{package}@dots{}
  4392. @end example
  4393. The following example spawns a new shell set up for the development of
  4394. GNU@tie{}Guile:
  4395. @example
  4396. guix environment guile
  4397. @end example
  4398. If the needed dependencies are not built yet, @command{guix environment}
  4399. automatically builds them. The environment of the new shell is an
  4400. augmented version of the environment that @command{guix environment} was
  4401. run in. It contains the necessary search paths for building the given
  4402. package added to the existing environment variables. To create
  4403. a ``pure'' environment, in which the original environment variables have
  4404. been unset, use the @option{--pure} option@footnote{Users sometimes
  4405. wrongfully augment environment variables such as @env{PATH} in their
  4406. @file{~/.bashrc} file. As a consequence, when @command{guix
  4407. environment} launches it, Bash may read @file{~/.bashrc}, thereby
  4408. introducing ``impurities'' in these environment variables. It is an
  4409. error to define such environment variables in @file{.bashrc}; instead,
  4410. they should be defined in @file{.bash_profile}, which is sourced only by
  4411. log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
  4412. Manual}, for details on Bash start-up files.}.
  4413. @vindex GUIX_ENVIRONMENT
  4414. @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
  4415. variable in the shell it spawns; its value is the file name of the
  4416. profile of this environment. This allows users to, say, define a
  4417. specific prompt for development environments in their @file{.bashrc}
  4418. (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
  4419. @example
  4420. if [ -n "$GUIX_ENVIRONMENT" ]
  4421. then
  4422. export PS1="\u@@\h \w [dev]\$ "
  4423. fi
  4424. @end example
  4425. @noindent
  4426. ...@: or to browse the profile:
  4427. @example
  4428. $ ls "$GUIX_ENVIRONMENT/bin"
  4429. @end example
  4430. Additionally, more than one package may be specified, in which case the
  4431. union of the inputs for the given packages are used. For example, the
  4432. command below spawns a shell where all of the dependencies of both Guile
  4433. and Emacs are available:
  4434. @example
  4435. guix environment guile emacs
  4436. @end example
  4437. Sometimes an interactive shell session is not desired. An arbitrary
  4438. command may be invoked by placing the @code{--} token to separate the
  4439. command from the rest of the arguments:
  4440. @example
  4441. guix environment guile -- make -j4
  4442. @end example
  4443. In other situations, it is more convenient to specify the list of
  4444. packages needed in the environment. For example, the following command
  4445. runs @command{python} from an environment containing Python@tie{}2.7 and
  4446. NumPy:
  4447. @example
  4448. guix environment --ad-hoc python2-numpy python-2.7 -- python
  4449. @end example
  4450. Furthermore, one might want the dependencies of a package and also some
  4451. additional packages that are not build-time or runtime dependencies, but
  4452. are useful when developing nonetheless. Because of this, the
  4453. @option{--ad-hoc} flag is positional. Packages appearing before
  4454. @option{--ad-hoc} are interpreted as packages whose dependencies will be
  4455. added to the environment. Packages appearing after are interpreted as
  4456. packages that will be added to the environment directly. For example,
  4457. the following command creates a Guix development environment that
  4458. additionally includes Git and strace:
  4459. @example
  4460. guix environment --pure guix --ad-hoc git strace
  4461. @end example
  4462. @cindex container
  4463. Sometimes it is desirable to isolate the environment as much as
  4464. possible, for maximal purity and reproducibility. In particular, when
  4465. using Guix on a host distro that is not Guix System, it is desirable to
  4466. prevent access to @file{/usr/bin} and other system-wide resources from
  4467. the development environment. For example, the following command spawns
  4468. a Guile REPL in a ``container'' where only the store and the current
  4469. working directory are mounted:
  4470. @example
  4471. guix environment --ad-hoc --container guile -- guile
  4472. @end example
  4473. @quotation Note
  4474. The @option{--container} option requires Linux-libre 3.19 or newer.
  4475. @end quotation
  4476. @cindex certificates
  4477. Another typical use case for containers is to run security-sensitive
  4478. applications such as a web browser. To run Eolie, we must expose and
  4479. share some files and directories; we include @code{nss-certs} and expose
  4480. @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
  4481. @env{DISPLAY} environment variable since containerized graphical
  4482. applications won't display without it.
  4483. @example
  4484. guix environment --preserve='^DISPLAY$' --container --network \
  4485. --expose=/etc/machine-id \
  4486. --expose=/etc/ssl/certs/ \
  4487. --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
  4488. --ad-hoc eolie nss-certs dbus -- eolie
  4489. @end example
  4490. The available options are summarized below.
  4491. @table @code
  4492. @item --root=@var{file}
  4493. @itemx -r @var{file}
  4494. @cindex persistent environment
  4495. @cindex garbage collector root, for environments
  4496. Make @var{file} a symlink to the profile for this environment, and
  4497. register it as a garbage collector root.
  4498. This is useful if you want to protect your environment from garbage
  4499. collection, to make it ``persistent''.
  4500. When this option is omitted, the environment is protected from garbage
  4501. collection only for the duration of the @command{guix environment}
  4502. session. This means that next time you recreate the same environment,
  4503. you could have to rebuild or re-download packages. @xref{Invoking guix
  4504. gc}, for more on GC roots.
  4505. @item --expression=@var{expr}
  4506. @itemx -e @var{expr}
  4507. Create an environment for the package or list of packages that
  4508. @var{expr} evaluates to.
  4509. For example, running:
  4510. @example
  4511. guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
  4512. @end example
  4513. starts a shell with the environment for this specific variant of the
  4514. PETSc package.
  4515. Running:
  4516. @example
  4517. guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
  4518. @end example
  4519. starts a shell with all the base system packages available.
  4520. The above commands only use the default output of the given packages.
  4521. To select other outputs, two element tuples can be specified:
  4522. @example
  4523. guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
  4524. @end example
  4525. @item --load=@var{file}
  4526. @itemx -l @var{file}
  4527. Create an environment for the package or list of packages that the code
  4528. within @var{file} evaluates to.
  4529. As an example, @var{file} might contain a definition like this
  4530. (@pxref{Defining Packages}):
  4531. @lisp
  4532. @verbatiminclude environment-gdb.scm
  4533. @end lisp
  4534. @item --manifest=@var{file}
  4535. @itemx -m @var{file}
  4536. Create an environment for the packages contained in the manifest object
  4537. returned by the Scheme code in @var{file}. This option can be repeated
  4538. several times, in which case the manifests are concatenated.
  4539. This is similar to the same-named option in @command{guix package}
  4540. (@pxref{profile-manifest, @option{--manifest}}) and uses the same
  4541. manifest files.
  4542. @item --ad-hoc
  4543. Include all specified packages in the resulting environment, as if an
  4544. @i{ad hoc} package were defined with them as inputs. This option is
  4545. useful for quickly creating an environment without having to write a
  4546. package expression to contain the desired inputs.
  4547. For instance, the command:
  4548. @example
  4549. guix environment --ad-hoc guile guile-sdl -- guile
  4550. @end example
  4551. runs @command{guile} in an environment where Guile and Guile-SDL are
  4552. available.
  4553. Note that this example implicitly asks for the default output of
  4554. @code{guile} and @code{guile-sdl}, but it is possible to ask for a
  4555. specific output---e.g., @code{glib:bin} asks for the @code{bin} output
  4556. of @code{glib} (@pxref{Packages with Multiple Outputs}).
  4557. This option may be composed with the default behavior of @command{guix
  4558. environment}. Packages appearing before @option{--ad-hoc} are
  4559. interpreted as packages whose dependencies will be added to the
  4560. environment, the default behavior. Packages appearing after are
  4561. interpreted as packages that will be added to the environment directly.
  4562. @item --pure
  4563. Unset existing environment variables when building the new environment, except
  4564. those specified with @option{--preserve} (see below). This has the effect of
  4565. creating an environment in which search paths only contain package inputs.
  4566. @item --preserve=@var{regexp}
  4567. @itemx -E @var{regexp}
  4568. When used alongside @option{--pure}, preserve the environment variables
  4569. matching @var{regexp}---in other words, put them on a ``white list'' of
  4570. environment variables that must be preserved. This option can be repeated
  4571. several times.
  4572. @example
  4573. guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
  4574. -- mpirun @dots{}
  4575. @end example
  4576. This example runs @command{mpirun} in a context where the only environment
  4577. variables defined are @env{PATH}, environment variables whose name starts
  4578. with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
  4579. @env{USER}, etc.).
  4580. @item --search-paths
  4581. Display the environment variable definitions that make up the
  4582. environment.
  4583. @item --system=@var{system}
  4584. @itemx -s @var{system}
  4585. Attempt to build for @var{system}---e.g., @code{i686-linux}.
  4586. @item --container
  4587. @itemx -C
  4588. @cindex container
  4589. Run @var{command} within an isolated container. The current working
  4590. directory outside the container is mapped inside the container.
  4591. Additionally, unless overridden with @option{--user}, a dummy home
  4592. directory is created that matches the current user's home directory, and
  4593. @file{/etc/passwd} is configured accordingly.
  4594. The spawned process runs as the current user outside the container. Inside
  4595. the container, it has the same UID and GID as the current user, unless
  4596. @option{--user} is passed (see below).
  4597. @item --network
  4598. @itemx -N
  4599. For containers, share the network namespace with the host system.
  4600. Containers created without this flag only have access to the loopback
  4601. device.
  4602. @item --link-profile
  4603. @itemx -P
  4604. For containers, link the environment profile to @file{~/.guix-profile}
  4605. within the container and set @code{GUIX_ENVIRONMENT} to that.
  4606. This is equivalent to making @file{~/.guix-profile} a symlink to the
  4607. actual profile within the container.
  4608. Linking will fail and abort the environment if the directory already
  4609. exists, which will certainly be the case if @command{guix environment}
  4610. was invoked in the user's home directory.
  4611. Certain packages are configured to look in @file{~/.guix-profile} for
  4612. configuration files and data;@footnote{For example, the
  4613. @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
  4614. for additional fonts.} @option{--link-profile} allows these programs to
  4615. behave as expected within the environment.
  4616. @item --user=@var{user}
  4617. @itemx -u @var{user}
  4618. For containers, use the username @var{user} in place of the current
  4619. user. The generated @file{/etc/passwd} entry within the container will
  4620. contain the name @var{user}, the home directory will be
  4621. @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
  4622. the UID and GID inside the container are 1000. @var{user}
  4623. need not exist on the system.
  4624. Additionally, any shared or exposed path (see @option{--share} and
  4625. @option{--expose} respectively) whose target is within the current user's
  4626. home directory will be remapped relative to @file{/home/USER}; this
  4627. includes the automatic mapping of the current working directory.
  4628. @example
  4629. # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
  4630. cd $HOME/wd
  4631. guix environment --container --user=foo \
  4632. --expose=$HOME/test \
  4633. --expose=/tmp/target=$HOME/target
  4634. @end example
  4635. While this will limit the leaking of user identity through home paths
  4636. and each of the user fields, this is only one useful component of a
  4637. broader privacy/anonymity solution---not one in and of itself.
  4638. @item --no-cwd
  4639. For containers, the default behavior is to share the current working
  4640. directory with the isolated container and immediately change to that
  4641. directory within the container. If this is undesirable,
  4642. @option{--no-cwd} will cause the current working directory to @emph{not}
  4643. be automatically shared and will change to the user's home directory
  4644. within the container instead. See also @option{--user}.
  4645. @item --expose=@var{source}[=@var{target}]
  4646. @itemx --share=@var{source}[=@var{target}]
  4647. For containers, @option{--expose} (resp. @option{--share}) exposes the
  4648. file system @var{source} from the host system as the read-only
  4649. (resp. writable) file system @var{target} within the container. If
  4650. @var{target} is not specified, @var{source} is used as the target mount
  4651. point in the container.
  4652. The example below spawns a Guile REPL in a container in which the user's
  4653. home directory is accessible read-only via the @file{/exchange}
  4654. directory:
  4655. @example
  4656. guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
  4657. @end example
  4658. @end table
  4659. @command{guix environment}
  4660. also supports all of the common build options that @command{guix
  4661. build} supports (@pxref{Common Build Options}) as well as package
  4662. transformation options (@pxref{Package Transformation Options}).
  4663. @node Invoking guix pack
  4664. @section Invoking @command{guix pack}
  4665. Occasionally you want to pass software to people who are not (yet!)
  4666. lucky enough to be using Guix. You'd tell them to run @command{guix
  4667. package -i @var{something}}, but that's not possible in this case. This
  4668. is where @command{guix pack} comes in.
  4669. @quotation Note
  4670. If you are looking for ways to exchange binaries among machines that
  4671. already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
  4672. publish}, and @ref{Invoking guix archive}.
  4673. @end quotation
  4674. @cindex pack
  4675. @cindex bundle
  4676. @cindex application bundle
  4677. @cindex software bundle
  4678. The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
  4679. @dfn{software bundle}: it creates a tarball or some other archive
  4680. containing the binaries of the software you're interested in, and all
  4681. its dependencies. The resulting archive can be used on any machine that
  4682. does not have Guix, and people can run the exact same binaries as those
  4683. you have with Guix. The pack itself is created in a bit-reproducible
  4684. fashion, so anyone can verify that it really contains the build results
  4685. that you pretend to be shipping.
  4686. For example, to create a bundle containing Guile, Emacs, Geiser, and all
  4687. their dependencies, you can run:
  4688. @example
  4689. $ guix pack guile emacs geiser
  4690. @dots{}
  4691. /gnu/store/@dots{}-pack.tar.gz
  4692. @end example
  4693. The result here is a tarball containing a @file{/gnu/store} directory
  4694. with all the relevant packages. The resulting tarball contains a
  4695. @dfn{profile} with the three packages of interest; the profile is the
  4696. same as would be created by @command{guix package -i}. It is this
  4697. mechanism that is used to create Guix's own standalone binary tarball
  4698. (@pxref{Binary Installation}).
  4699. Users of this pack would have to run
  4700. @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
  4701. find inconvenient. To work around it, you can create, say, a
  4702. @file{/opt/gnu/bin} symlink to the profile:
  4703. @example
  4704. guix pack -S /opt/gnu/bin=bin guile emacs geiser
  4705. @end example
  4706. @noindent
  4707. That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
  4708. @cindex relocatable binaries, with @command{guix pack}
  4709. What if the recipient of your pack does not have root privileges on
  4710. their machine, and thus cannot unpack it in the root file system? In
  4711. that case, you will want to use the @option{--relocatable} option (see
  4712. below). This option produces @dfn{relocatable binaries}, meaning they
  4713. they can be placed anywhere in the file system hierarchy: in the example
  4714. above, users can unpack your tarball in their home directory and
  4715. directly run @file{./opt/gnu/bin/guile}.
  4716. @cindex Docker, build an image with guix pack
  4717. Alternatively, you can produce a pack in the Docker image format using
  4718. the following command:
  4719. @example
  4720. guix pack -f docker -S /bin=bin guile guile-readline
  4721. @end example
  4722. @noindent
  4723. The result is a tarball that can be passed to the @command{docker load}
  4724. command, followed by @code{docker run}:
  4725. @example
  4726. docker load < @var{file}
  4727. docker run -ti guile-guile-readline /bin/guile
  4728. @end example
  4729. @noindent
  4730. where @var{file} is the image returned by @var{guix pack}, and
  4731. @code{guile-guile-readline} is its ``image tag''. See the
  4732. @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
  4733. documentation} for more information.
  4734. @cindex Singularity, build an image with guix pack
  4735. @cindex SquashFS, build an image with guix pack
  4736. Yet another option is to produce a SquashFS image with the following
  4737. command:
  4738. @example
  4739. guix pack -f squashfs bash guile emacs geiser
  4740. @end example
  4741. @noindent
  4742. The result is a SquashFS file system image that can either be mounted or
  4743. directly be used as a file system container image with the
  4744. @uref{https://www.sylabs.io/docs/, Singularity container execution
  4745. environment}, using commands like @command{singularity shell} or
  4746. @command{singularity exec}.
  4747. Several command-line options allow you to customize your pack:
  4748. @table @code
  4749. @item --format=@var{format}
  4750. @itemx -f @var{format}
  4751. Produce a pack in the given @var{format}.
  4752. The available formats are:
  4753. @table @code
  4754. @item tarball
  4755. This is the default format. It produces a tarball containing all the
  4756. specified binaries and symlinks.
  4757. @item docker
  4758. This produces a tarball that follows the
  4759. @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
  4760. Docker Image Specification}. The ``repository name'' as it appears in
  4761. the output of the @command{docker images} command is computed from
  4762. package names passed on the command line or in the manifest file.
  4763. @item squashfs
  4764. This produces a SquashFS image containing all the specified binaries and
  4765. symlinks, as well as empty mount points for virtual file systems like
  4766. procfs.
  4767. @quotation Note
  4768. Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
  4769. For that reason, @command{guix pack -f squashfs} always implies @code{-S
  4770. /bin=bin}. Thus, your @command{guix pack} invocation must always start
  4771. with something like:
  4772. @example
  4773. guix pack -f squashfs bash @dots{}
  4774. @end example
  4775. If you forget the @code{bash} (or similar) package, @command{singularity
  4776. run} and @command{singularity exec} will fail with an unhelpful ``no
  4777. such file or directory'' message.
  4778. @end quotation
  4779. @end table
  4780. @cindex relocatable binaries
  4781. @item --relocatable
  4782. @itemx -R
  4783. Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
  4784. anywhere in the file system hierarchy and run from there.
  4785. When this option is passed once, the resulting binaries require support for
  4786. @dfn{user namespaces} in the kernel Linux; when passed
  4787. @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
  4788. PRoot support, can be thought of as the abbreviation of ``Really
  4789. Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
  4790. other techniques if user namespaces are unavailable, and essentially
  4791. work anywhere---see below for the implications.
  4792. For example, if you create a pack containing Bash with:
  4793. @example
  4794. guix pack -RR -S /mybin=bin bash
  4795. @end example
  4796. @noindent
  4797. ...@: you can copy that pack to a machine that lacks Guix, and from your
  4798. home directory as a normal user, run:
  4799. @example
  4800. tar xf pack.tar.gz
  4801. ./mybin/sh
  4802. @end example
  4803. @noindent
  4804. In that shell, if you type @code{ls /gnu/store}, you'll notice that
  4805. @file{/gnu/store} shows up and contains all the dependencies of
  4806. @code{bash}, even though the machine actually lacks @file{/gnu/store}
  4807. altogether! That is probably the simplest way to deploy Guix-built
  4808. software on a non-Guix machine.
  4809. @quotation Note
  4810. By default, relocatable binaries rely on the @dfn{user namespace} feature of
  4811. the kernel Linux, which allows unprivileged users to mount or change root.
  4812. Old versions of Linux did not support it, and some GNU/Linux distributions
  4813. turn it off.
  4814. To produce relocatable binaries that work even in the absence of user
  4815. namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
  4816. case, binaries will try user namespace support and fall back to another
  4817. @dfn{execution engine} if user namespaces are not supported. The
  4818. following execution engines are supported:
  4819. @table @code
  4820. @item default
  4821. Try user namespaces and fall back to PRoot if user namespaces are not
  4822. supported (see below).
  4823. @item performance
  4824. Try user namespaces and fall back to Fakechroot if user namespaces are
  4825. not supported (see below).
  4826. @item userns
  4827. Run the program through user namespaces and abort if they are not
  4828. supported.
  4829. @item proot
  4830. Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
  4831. provides the necessary
  4832. support for file system virtualization. It achieves that by using the
  4833. @code{ptrace} system call on the running program. This approach has the
  4834. advantage to work without requiring special kernel support, but it incurs
  4835. run-time overhead every time a system call is made.
  4836. @item fakechroot
  4837. Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
  4838. Fakechroot} virtualizes file system accesses by intercepting calls to C
  4839. library functions such as @code{open}, @code{stat}, @code{exec}, and so
  4840. on. Unlike PRoot, it incurs very little overhead. However, it does not
  4841. always work: for example, some file system accesses made from within the
  4842. C library are not intercepted, and file system accesses made @i{via}
  4843. direct syscalls are not intercepted either, leading to erratic behavior.
  4844. @end table
  4845. @vindex GUIX_EXECUTION_ENGINE
  4846. When running a wrapped program, you can explicitly request one of the
  4847. execution engines listed above by setting the
  4848. @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
  4849. @end quotation
  4850. @cindex entry point, for Docker images
  4851. @item --entry-point=@var{command}
  4852. Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
  4853. format supports it---currently @code{docker} and @code{squashfs} (Singularity)
  4854. support it. @var{command} must be relative to the profile contained in the
  4855. pack.
  4856. The entry point specifies the command that tools like @code{docker run} or
  4857. @code{singularity run} automatically start by default. For example, you can
  4858. do:
  4859. @example
  4860. guix pack -f docker --entry-point=bin/guile guile
  4861. @end example
  4862. The resulting pack can easily be loaded and @code{docker run} with no extra
  4863. arguments will spawn @code{bin/guile}:
  4864. @example
  4865. docker load -i pack.tar.gz
  4866. docker run @var{image-id}
  4867. @end example
  4868. @item --expression=@var{expr}
  4869. @itemx -e @var{expr}
  4870. Consider the package @var{expr} evaluates to.
  4871. This has the same purpose as the same-named option in @command{guix
  4872. build} (@pxref{Additional Build Options, @option{--expression} in
  4873. @command{guix build}}).
  4874. @item --manifest=@var{file}
  4875. @itemx -m @var{file}
  4876. Use the packages contained in the manifest object returned by the Scheme
  4877. code in @var{file}. This option can be repeated several times, in which
  4878. case the manifests are concatenated.
  4879. This has a similar purpose as the same-named option in @command{guix
  4880. package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
  4881. same manifest files. It allows you to define a collection of packages
  4882. once and use it both for creating profiles and for creating archives
  4883. for use on machines that do not have Guix installed. Note that you can
  4884. specify @emph{either} a manifest file @emph{or} a list of packages,
  4885. but not both.
  4886. @item --system=@var{system}
  4887. @itemx -s @var{system}
  4888. Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
  4889. the system type of the build host.
  4890. @item --target=@var{triplet}
  4891. @cindex cross-compilation
  4892. Cross-build for @var{triplet}, which must be a valid GNU triplet, such
  4893. as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
  4894. configuration triplets,, autoconf, Autoconf}).
  4895. @item --compression=@var{tool}
  4896. @itemx -C @var{tool}
  4897. Compress the resulting tarball using @var{tool}---one of @code{gzip},
  4898. @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
  4899. compression.
  4900. @item --symlink=@var{spec}
  4901. @itemx -S @var{spec}
  4902. Add the symlinks specified by @var{spec} to the pack. This option can
  4903. appear several times.
  4904. @var{spec} has the form @code{@var{source}=@var{target}}, where
  4905. @var{source} is the symlink that will be created and @var{target} is the
  4906. symlink target.
  4907. For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
  4908. symlink pointing to the @file{bin} sub-directory of the profile.
  4909. @item --save-provenance
  4910. Save provenance information for the packages passed on the command line.
  4911. Provenance information includes the URL and commit of the channels in use
  4912. (@pxref{Channels}).
  4913. Provenance information is saved in the
  4914. @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
  4915. usual package metadata---the name and version of each package, their
  4916. propagated inputs, and so on. It is useful information to the recipient of
  4917. the pack, who then knows how the pack was (supposedly) obtained.
  4918. This option is not enabled by default because, like timestamps, provenance
  4919. information contributes nothing to the build process. In other words, there
  4920. is an infinity of channel URLs and commit IDs that can lead to the same pack.
  4921. Recording such ``silent'' metadata in the output thus potentially breaks the
  4922. source-to-binary bitwise reproducibility property.
  4923. @item --root=@var{file}
  4924. @itemx -r @var{file}
  4925. @cindex garbage collector root, for packs
  4926. Make @var{file} a symlink to the resulting pack, and register it as a garbage
  4927. collector root.
  4928. @item --localstatedir
  4929. @itemx --profile-name=@var{name}
  4930. Include the ``local state directory'', @file{/var/guix}, in the resulting
  4931. pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
  4932. profile---by default @var{name} is @code{guix-profile}, which corresponds to
  4933. @file{~root/.guix-profile}.
  4934. @file{/var/guix} contains the store database (@pxref{The Store}) as well
  4935. as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
  4936. the pack means that the store is ``complete'' and manageable by Guix;
  4937. not providing it pack means that the store is ``dead'': items cannot be
  4938. added to it or removed from it after extraction of the pack.
  4939. One use case for this is the Guix self-contained binary tarball
  4940. (@pxref{Binary Installation}).
  4941. @item --derivation
  4942. @itemx -d
  4943. Print the name of the derivation that builds the pack.
  4944. @item --bootstrap
  4945. Use the bootstrap binaries to build the pack. This option is only
  4946. useful to Guix developers.
  4947. @end table
  4948. In addition, @command{guix pack} supports all the common build options
  4949. (@pxref{Common Build Options}) and all the package transformation
  4950. options (@pxref{Package Transformation Options}).
  4951. @node The GCC toolchain
  4952. @section The GCC toolchain
  4953. @cindex GCC
  4954. @cindex ld-wrapper
  4955. @cindex linker wrapper
  4956. @cindex toolchain, for C development
  4957. @cindex toolchain, for Fortran development
  4958. If you need a complete toolchain for compiling and linking C or C++
  4959. source code, use the @code{gcc-toolchain} package. This package
  4960. provides a complete GCC toolchain for C/C++ development, including GCC
  4961. itself, the GNU C Library (headers and binaries, plus debugging symbols
  4962. in the @code{debug} output), Binutils, and a linker wrapper.
  4963. The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
  4964. passed to the linker, add corresponding @code{-rpath} arguments, and
  4965. invoke the actual linker with this new set of arguments. You can instruct the
  4966. wrapper to refuse to link against libraries not in the store by setting the
  4967. @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
  4968. The package @code{gfortran-toolchain} provides a complete GCC toolchain
  4969. for Fortran development. For other languages, please use
  4970. @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
  4971. @node Invoking guix git authenticate
  4972. @section Invoking @command{guix git authenticate}
  4973. The @command{guix git authenticate} command authenticates a Git checkout
  4974. following the same rule as for channels (@pxref{channel-authentication,
  4975. channel authentication}). That is, starting from a given commit, it
  4976. ensures that all subsequent commits are signed by an OpenPGP key whose
  4977. fingerprint appears in the @file{.guix-authorizations} file of its
  4978. parent commit(s).
  4979. You will find this command useful if you maintain a channel. But in
  4980. fact, this authentication mechanism is useful in a broader context, so
  4981. you might want to use it for Git repositories that have nothing to do
  4982. with Guix.
  4983. The general syntax is:
  4984. @example
  4985. guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
  4986. @end example
  4987. By default, this command authenticates the Git checkout in the current
  4988. directory; it outputs nothing and exits with exit code zero on success
  4989. and non-zero on failure. @var{commit} above denotes the first commit
  4990. where authentication takes place, and @var{signer} is the OpenPGP
  4991. fingerprint of public key used to sign @var{commit}. Together, they
  4992. form a ``channel introduction'' (@pxref{channel-authentication, channel
  4993. introduction}). The options below allow you to fine-tune the process.
  4994. @table @code
  4995. @item --repository=@var{directory}
  4996. @itemx -r @var{directory}
  4997. Open the Git repository in @var{directory} instead of the current
  4998. directory.
  4999. @item --keyring=@var{reference}
  5000. @itemx -k @var{reference}
  5001. Load OpenPGP keyring from @var{reference}, the reference of a branch
  5002. such as @code{origin/keyring} or @code{my-keyring}. The branch must
  5003. contain OpenPGP public keys in @file{.key} files, either in binary form
  5004. or ``ASCII-armored''. By default the keyring is loaded from the branch
  5005. named @code{keyring}.
  5006. @item --stats
  5007. Display commit signing statistics upon completion.
  5008. @item --cache-key=@var{key}
  5009. Previously-authenticated commits are cached in a file under
  5010. @file{~/.cache/guix/authentication}. This option forces the cache to be
  5011. stored in file @var{key} in that directory.
  5012. @item --historical-authorizations=@var{file}
  5013. By default, any commit whose parent commit(s) lack the
  5014. @file{.guix-authorizations} file is considered inauthentic. In
  5015. contrast, this option considers the authorizations in @var{file} for any
  5016. commit that lacks @file{.guix-authorizations}. The format of @var{file}
  5017. is the same as that of @file{.guix-authorizations}
  5018. (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
  5019. @end table
  5020. @c *********************************************************************
  5021. @node Programming Interface
  5022. @chapter Programming Interface
  5023. GNU Guix provides several Scheme programming interfaces (APIs) to
  5024. define, build, and query packages. The first interface allows users to
  5025. write high-level package definitions. These definitions refer to
  5026. familiar packaging concepts, such as the name and version of a package,
  5027. its build system, and its dependencies. These definitions can then be
  5028. turned into concrete build actions.
  5029. Build actions are performed by the Guix daemon, on behalf of users. In a
  5030. standard setup, the daemon has write access to the store---the
  5031. @file{/gnu/store} directory---whereas users do not. The recommended
  5032. setup also has the daemon perform builds in chroots, under specific
  5033. build users, to minimize interference with the rest of the system.
  5034. @cindex derivation
  5035. Lower-level APIs are available to interact with the daemon and the
  5036. store. To instruct the daemon to perform a build action, users actually
  5037. provide it with a @dfn{derivation}. A derivation is a low-level
  5038. representation of the build actions to be taken, and the environment in
  5039. which they should occur---derivations are to package definitions what
  5040. assembly is to C programs. The term ``derivation'' comes from the fact
  5041. that build results @emph{derive} from them.
  5042. This chapter describes all these APIs in turn, starting from high-level
  5043. package definitions.
  5044. @menu
  5045. * Package Modules:: Packages from the programmer's viewpoint.
  5046. * Defining Packages:: Defining new packages.
  5047. * Defining Package Variants:: Customizing packages.
  5048. * Build Systems:: Specifying how packages are built.
  5049. * Build Phases:: Phases of the build process of a package.
  5050. * Build Utilities:: Helpers for your package definitions and more.
  5051. * The Store:: Manipulating the package store.
  5052. * Derivations:: Low-level interface to package derivations.
  5053. * The Store Monad:: Purely functional interface to the store.
  5054. * G-Expressions:: Manipulating build expressions.
  5055. * Invoking guix repl:: Programming Guix in Guile
  5056. @end menu
  5057. @node Package Modules
  5058. @section Package Modules
  5059. From a programming viewpoint, the package definitions of the
  5060. GNU distribution are provided by Guile modules in the @code{(gnu packages
  5061. @dots{})} name space@footnote{Note that packages under the @code{(gnu
  5062. packages @dots{})} module name space are not necessarily ``GNU
  5063. packages''. This module naming scheme follows the usual Guile module
  5064. naming convention: @code{gnu} means that these modules are distributed
  5065. as part of the GNU system, and @code{packages} identifies modules that
  5066. define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
  5067. Reference Manual}). For instance, the @code{(gnu packages emacs)}
  5068. module exports a variable named @code{emacs}, which is bound to a
  5069. @code{<package>} object (@pxref{Defining Packages}).
  5070. The @code{(gnu packages @dots{})} module name space is
  5071. automatically scanned for packages by the command-line tools. For
  5072. instance, when running @code{guix install emacs}, all the @code{(gnu
  5073. packages @dots{})} modules are scanned until one that exports a package
  5074. object whose name is @code{emacs} is found. This package search
  5075. facility is implemented in the @code{(gnu packages)} module.
  5076. @cindex customization, of packages
  5077. @cindex package module search path
  5078. Users can store package definitions in modules with different
  5079. names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
  5080. name and module name must match. For instance, the @code{(my-packages
  5081. emacs)} module must be stored in a @file{my-packages/emacs.scm} file
  5082. relative to the load path specified with @option{--load-path} or
  5083. @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
  5084. guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
  5085. these package definitions visible to the user interfaces:
  5086. @enumerate
  5087. @item
  5088. By adding the directory containing your package modules to the search path
  5089. with the @code{-L} flag of @command{guix package} and other commands
  5090. (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
  5091. environment variable described below.
  5092. @item
  5093. By defining a @dfn{channel} and configuring @command{guix pull} so that it
  5094. pulls from it. A channel is essentially a Git repository containing package
  5095. modules. @xref{Channels}, for more information on how to define and use
  5096. channels.
  5097. @end enumerate
  5098. @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
  5099. @defvr {Environment Variable} GUIX_PACKAGE_PATH
  5100. This is a colon-separated list of directories to search for additional
  5101. package modules. Directories listed in this variable take precedence
  5102. over the own modules of the distribution.
  5103. @end defvr
  5104. The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
  5105. each package is built based solely on other packages in the
  5106. distribution. The root of this dependency graph is a small set of
  5107. @dfn{bootstrap binaries}, provided by the @code{(gnu packages
  5108. bootstrap)} module. For more information on bootstrapping,
  5109. @pxref{Bootstrapping}.
  5110. @node Defining Packages
  5111. @section Defining Packages
  5112. The high-level interface to package definitions is implemented in the
  5113. @code{(guix packages)} and @code{(guix build-system)} modules. As an
  5114. example, the package definition, or @dfn{recipe}, for the GNU Hello
  5115. package looks like this:
  5116. @lisp
  5117. (define-module (gnu packages hello)
  5118. #:use-module (guix packages)
  5119. #:use-module (guix download)
  5120. #:use-module (guix build-system gnu)
  5121. #:use-module (guix licenses)
  5122. #:use-module (gnu packages gawk))
  5123. (define-public hello
  5124. (package
  5125. (name "hello")
  5126. (version "2.10")
  5127. (source (origin
  5128. (method url-fetch)
  5129. (uri (string-append "mirror://gnu/hello/hello-" version
  5130. ".tar.gz"))
  5131. (sha256
  5132. (base32
  5133. "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
  5134. (build-system gnu-build-system)
  5135. (arguments '(#:configure-flags '("--enable-silent-rules")))
  5136. (inputs `(("gawk" ,gawk)))
  5137. (synopsis "Hello, GNU world: An example GNU package")
  5138. (description "Guess what GNU Hello prints!")
  5139. (home-page "https://www.gnu.org/software/hello/")
  5140. (license gpl3+)))
  5141. @end lisp
  5142. @noindent
  5143. Without being a Scheme expert, the reader may have guessed the meaning
  5144. of the various fields here. This expression binds the variable
  5145. @code{hello} to a @code{<package>} object, which is essentially a record
  5146. (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
  5147. This package object can be inspected using procedures found in the
  5148. @code{(guix packages)} module; for instance, @code{(package-name hello)}
  5149. returns---surprise!---@code{"hello"}.
  5150. With luck, you may be able to import part or all of the definition of
  5151. the package you are interested in from another repository, using the
  5152. @code{guix import} command (@pxref{Invoking guix import}).
  5153. In the example above, @code{hello} is defined in a module of its own,
  5154. @code{(gnu packages hello)}. Technically, this is not strictly
  5155. necessary, but it is convenient to do so: all the packages defined in
  5156. modules under @code{(gnu packages @dots{})} are automatically known to
  5157. the command-line tools (@pxref{Package Modules}).
  5158. There are a few points worth noting in the above package definition:
  5159. @itemize
  5160. @item
  5161. The @code{source} field of the package is an @code{<origin>} object
  5162. (@pxref{origin Reference}, for the complete reference).
  5163. Here, the @code{url-fetch} method from @code{(guix download)} is used,
  5164. meaning that the source is a file to be downloaded over FTP or HTTP.
  5165. The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
  5166. the GNU mirrors defined in @code{(guix download)}.
  5167. The @code{sha256} field specifies the expected SHA256 hash of the file
  5168. being downloaded. It is mandatory, and allows Guix to check the
  5169. integrity of the file. The @code{(base32 @dots{})} form introduces the
  5170. base32 representation of the hash. You can obtain this information with
  5171. @code{guix download} (@pxref{Invoking guix download}) and @code{guix
  5172. hash} (@pxref{Invoking guix hash}).
  5173. @cindex patches
  5174. When needed, the @code{origin} form can also have a @code{patches} field
  5175. listing patches to be applied, and a @code{snippet} field giving a
  5176. Scheme expression to modify the source code.
  5177. @item
  5178. @cindex GNU Build System
  5179. The @code{build-system} field specifies the procedure to build the
  5180. package (@pxref{Build Systems}). Here, @code{gnu-build-system}
  5181. represents the familiar GNU Build System, where packages may be
  5182. configured, built, and installed with the usual @code{./configure &&
  5183. make && make check && make install} command sequence.
  5184. When you start packaging non-trivial software, you may need tools to
  5185. manipulate those build phases, manipulate files, and so on. @xref{Build
  5186. Utilities}, for more on this.
  5187. @item
  5188. The @code{arguments} field specifies options for the build system
  5189. (@pxref{Build Systems}). Here it is interpreted by
  5190. @code{gnu-build-system} as a request run @file{configure} with the
  5191. @option{--enable-silent-rules} flag.
  5192. @cindex quote
  5193. @cindex quoting
  5194. @findex '
  5195. @findex quote
  5196. What about these quote (@code{'}) characters? They are Scheme syntax to
  5197. introduce a literal list; @code{'} is synonymous with @code{quote}.
  5198. @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
  5199. for details. Here the value of the @code{arguments} field is a list of
  5200. arguments passed to the build system down the road, as with @code{apply}
  5201. (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
  5202. Manual}).
  5203. The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
  5204. (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
  5205. @code{#:configure-flags} is a keyword used to pass a keyword argument
  5206. to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
  5207. Reference Manual}).
  5208. @item
  5209. The @code{inputs} field specifies inputs to the build process---i.e.,
  5210. build-time or run-time dependencies of the package. Here, we define an
  5211. input called @code{"gawk"} whose value is that of the @code{gawk}
  5212. variable; @code{gawk} is itself bound to a @code{<package>} object.
  5213. @cindex backquote (quasiquote)
  5214. @findex `
  5215. @findex quasiquote
  5216. @cindex comma (unquote)
  5217. @findex ,
  5218. @findex unquote
  5219. @findex ,@@
  5220. @findex unquote-splicing
  5221. Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
  5222. us to introduce a literal list in the @code{inputs} field, while
  5223. @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
  5224. value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
  5225. Reference Manual}).
  5226. Note that GCC, Coreutils, Bash, and other essential tools do not need to
  5227. be specified as inputs here. Instead, @code{gnu-build-system} takes care
  5228. of ensuring that they are present (@pxref{Build Systems}).
  5229. However, any other dependencies need to be specified in the
  5230. @code{inputs} field. Any dependency not specified here will simply be
  5231. unavailable to the build process, possibly leading to a build failure.
  5232. @end itemize
  5233. @xref{package Reference}, for a full description of possible fields.
  5234. Once a package definition is in place, the
  5235. package may actually be built using the @code{guix build} command-line
  5236. tool (@pxref{Invoking guix build}), troubleshooting any build failures
  5237. you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
  5238. package definition using the @command{guix edit} command
  5239. (@pxref{Invoking guix edit}).
  5240. @xref{Packaging Guidelines}, for
  5241. more information on how to test package definitions, and
  5242. @ref{Invoking guix lint}, for information on how to check a definition
  5243. for style conformance.
  5244. @vindex GUIX_PACKAGE_PATH
  5245. Lastly, @pxref{Channels}, for information
  5246. on how to extend the distribution by adding your own package definitions
  5247. in a ``channel''.
  5248. Finally, updating the package definition to a new upstream version
  5249. can be partly automated by the @command{guix refresh} command
  5250. (@pxref{Invoking guix refresh}).
  5251. Behind the scenes, a derivation corresponding to the @code{<package>}
  5252. object is first computed by the @code{package-derivation} procedure.
  5253. That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
  5254. The build actions it prescribes may then be realized by using the
  5255. @code{build-derivations} procedure (@pxref{The Store}).
  5256. @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
  5257. Return the @code{<derivation>} object of @var{package} for @var{system}
  5258. (@pxref{Derivations}).
  5259. @var{package} must be a valid @code{<package>} object, and @var{system}
  5260. must be a string denoting the target system type---e.g.,
  5261. @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
  5262. must be a connection to the daemon, which operates on the store
  5263. (@pxref{The Store}).
  5264. @end deffn
  5265. @noindent
  5266. @cindex cross-compilation
  5267. Similarly, it is possible to compute a derivation that cross-builds a
  5268. package for some other system:
  5269. @deffn {Scheme Procedure} package-cross-derivation @var{store} @
  5270. @var{package} @var{target} [@var{system}]
  5271. Return the @code{<derivation>} object of @var{package} cross-built from
  5272. @var{system} to @var{target}.
  5273. @var{target} must be a valid GNU triplet denoting the target hardware
  5274. and operating system, such as @code{"aarch64-linux-gnu"}
  5275. (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
  5276. @end deffn
  5277. Once you have package definitions, you can easily define @emph{variants}
  5278. of those packages. @xref{Defining Package Variants}, for more on that.
  5279. @menu
  5280. * package Reference:: The package data type.
  5281. * origin Reference:: The origin data type.
  5282. @end menu
  5283. @node package Reference
  5284. @subsection @code{package} Reference
  5285. This section summarizes all the options available in @code{package}
  5286. declarations (@pxref{Defining Packages}).
  5287. @deftp {Data Type} package
  5288. This is the data type representing a package recipe.
  5289. @table @asis
  5290. @item @code{name}
  5291. The name of the package, as a string.
  5292. @item @code{version}
  5293. The version of the package, as a string.
  5294. @item @code{source}
  5295. An object telling how the source code for the package should be
  5296. acquired. Most of the time, this is an @code{origin} object, which
  5297. denotes a file fetched from the Internet (@pxref{origin Reference}). It
  5298. can also be any other ``file-like'' object such as a @code{local-file},
  5299. which denotes a file from the local file system (@pxref{G-Expressions,
  5300. @code{local-file}}).
  5301. @item @code{build-system}
  5302. The build system that should be used to build the package (@pxref{Build
  5303. Systems}).
  5304. @item @code{arguments} (default: @code{'()})
  5305. The arguments that should be passed to the build system. This is a
  5306. list, typically containing sequential keyword-value pairs.
  5307. @item @code{inputs} (default: @code{'()})
  5308. @itemx @code{native-inputs} (default: @code{'()})
  5309. @itemx @code{propagated-inputs} (default: @code{'()})
  5310. @cindex inputs, of packages
  5311. These fields list dependencies of the package. Each one is a list of
  5312. tuples, where each tuple has a label for the input (a string) as its
  5313. first element, a package, origin, or derivation as its second element,
  5314. and optionally the name of the output thereof that should be used, which
  5315. defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
  5316. more on package outputs). For example, the list below specifies three
  5317. inputs:
  5318. @lisp
  5319. `(("libffi" ,libffi)
  5320. ("libunistring" ,libunistring)
  5321. ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
  5322. @end lisp
  5323. @cindex cross compilation, package dependencies
  5324. The distinction between @code{native-inputs} and @code{inputs} is
  5325. necessary when considering cross-compilation. When cross-compiling,
  5326. dependencies listed in @code{inputs} are built for the @emph{target}
  5327. architecture; conversely, dependencies listed in @code{native-inputs}
  5328. are built for the architecture of the @emph{build} machine.
  5329. @code{native-inputs} is typically used to list tools needed at
  5330. build time, but not at run time, such as Autoconf, Automake, pkg-config,
  5331. Gettext, or Bison. @command{guix lint} can report likely mistakes in
  5332. this area (@pxref{Invoking guix lint}).
  5333. @anchor{package-propagated-inputs}
  5334. Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
  5335. specified packages will be automatically installed to profiles
  5336. (@pxref{Features, the role of profiles in Guix}) alongside the package
  5337. they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
  5338. package}}, for information on how @command{guix package} deals with
  5339. propagated inputs).
  5340. For example this is necessary when packaging a C/C++ library that needs
  5341. headers of another library to compile, or when a pkg-config file refers
  5342. to another one @i{via} its @code{Requires} field.
  5343. Another example where @code{propagated-inputs} is useful is for languages
  5344. that lack a facility to record the run-time search path akin to the
  5345. @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
  5346. more. When packaging libraries written in those languages, ensure they
  5347. can find library code they depend on at run time by listing run-time
  5348. dependencies in @code{propagated-inputs} rather than @code{inputs}.
  5349. @item @code{outputs} (default: @code{'("out")})
  5350. The list of output names of the package. @xref{Packages with Multiple
  5351. Outputs}, for typical uses of additional outputs.
  5352. @item @code{native-search-paths} (default: @code{'()})
  5353. @itemx @code{search-paths} (default: @code{'()})
  5354. A list of @code{search-path-specification} objects describing
  5355. search-path environment variables honored by the package.
  5356. @item @code{replacement} (default: @code{#f})
  5357. This must be either @code{#f} or a package object that will be used as a
  5358. @dfn{replacement} for this package. @xref{Security Updates, grafts},
  5359. for details.
  5360. @item @code{synopsis}
  5361. A one-line description of the package.
  5362. @item @code{description}
  5363. A more elaborate description of the package.
  5364. @item @code{license}
  5365. @cindex license, of packages
  5366. The license of the package; a value from @code{(guix licenses)},
  5367. or a list of such values.
  5368. @item @code{home-page}
  5369. The URL to the home-page of the package, as a string.
  5370. @item @code{supported-systems} (default: @code{%supported-systems})
  5371. The list of systems supported by the package, as strings of the form
  5372. @code{architecture-kernel}, for example @code{"x86_64-linux"}.
  5373. @item @code{location} (default: source location of the @code{package} form)
  5374. The source location of the package. It is useful to override this when
  5375. inheriting from another package, in which case this field is not
  5376. automatically corrected.
  5377. @end table
  5378. @end deftp
  5379. @deffn {Scheme Syntax} this-package
  5380. When used in the @emph{lexical scope} of a package field definition, this
  5381. identifier resolves to the package being defined.
  5382. The example below shows how to add a package as a native input of itself when
  5383. cross-compiling:
  5384. @lisp
  5385. (package
  5386. (name "guile")
  5387. ;; ...
  5388. ;; When cross-compiled, Guile, for example, depends on
  5389. ;; a native version of itself. Add it here.
  5390. (native-inputs (if (%current-target-system)
  5391. `(("self" ,this-package))
  5392. '())))
  5393. @end lisp
  5394. It is an error to refer to @code{this-package} outside a package definition.
  5395. @end deffn
  5396. Because packages are regular Scheme objects that capture a complete
  5397. dependency graph and associated build procedures, it is often useful to
  5398. write procedures that take a package and return a modified version
  5399. thereof according to some parameters. Below are a few examples.
  5400. @cindex tool chain, choosing a package's tool chain
  5401. @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
  5402. Return a variant of @var{package} that uses @var{toolchain} instead of
  5403. the default GNU C/C++ toolchain. @var{toolchain} must be a list of
  5404. inputs (label/package tuples) providing equivalent functionality, such
  5405. as the @code{gcc-toolchain} package.
  5406. The example below returns a variant of the @code{hello} package built
  5407. with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
  5408. GNU C Library) instead of the default tool chain:
  5409. @lisp
  5410. (let ((toolchain (specification->package "gcc-toolchain@@10")))
  5411. (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
  5412. @end lisp
  5413. The build tool chain is part of the @dfn{implicit inputs} of
  5414. packages---it's usually not listed as part of the various ``inputs''
  5415. fields and is instead pulled in by the build system. Consequently, this
  5416. procedure works by changing the build system of @var{package} so that it
  5417. pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
  5418. for more on build systems.
  5419. @end deffn
  5420. @node origin Reference
  5421. @subsection @code{origin} Reference
  5422. This section documents @dfn{origins}. An @code{origin} declaration
  5423. specifies data that must be ``produced''---downloaded, usually---and
  5424. whose content hash is known in advance. Origins are primarily used to
  5425. represent the source code of packages (@pxref{Defining Packages}). For
  5426. that reason, the @code{origin} form allows you to declare patches to
  5427. apply to the original source code as well as code snippets to modify it.
  5428. @deftp {Data Type} origin
  5429. This is the data type representing a source code origin.
  5430. @table @asis
  5431. @item @code{uri}
  5432. An object containing the URI of the source. The object type depends on
  5433. the @code{method} (see below). For example, when using the
  5434. @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
  5435. values are: a URL represented as a string, or a list thereof.
  5436. @cindex fixed-output derivations, for download
  5437. @item @code{method}
  5438. A monadic procedure that handles the given URI@. The procedure must
  5439. accept at least three arguments: the value of the @code{uri} field and
  5440. the hash algorithm and hash value specified by the @code{hash} field.
  5441. It must return a store item or a derivation in the store monad
  5442. (@pxref{The Store Monad}); most methods return a fixed-output derivation
  5443. (@pxref{Derivations}).
  5444. Commonly used methods include @code{url-fetch}, which fetches data from
  5445. a URL, and @code{git-fetch}, which fetches data from a Git repository
  5446. (see below).
  5447. @item @code{sha256}
  5448. A bytevector containing the SHA-256 hash of the source. This is
  5449. equivalent to providing a @code{content-hash} SHA256 object in the
  5450. @code{hash} field described below.
  5451. @item @code{hash}
  5452. The @code{content-hash} object of the source---see below for how to use
  5453. @code{content-hash}.
  5454. You can obtain this information using @code{guix download}
  5455. (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
  5456. guix hash}).
  5457. @item @code{file-name} (default: @code{#f})
  5458. The file name under which the source code should be saved. When this is
  5459. @code{#f}, a sensible default value will be used in most cases. In case
  5460. the source is fetched from a URL, the file name from the URL will be
  5461. used. For version control checkouts, it is recommended to provide the
  5462. file name explicitly because the default is not very descriptive.
  5463. @item @code{patches} (default: @code{'()})
  5464. A list of file names, origins, or file-like objects (@pxref{G-Expressions,
  5465. file-like objects}) pointing to patches to be applied to the source.
  5466. This list of patches must be unconditional. In particular, it cannot
  5467. depend on the value of @code{%current-system} or
  5468. @code{%current-target-system}.
  5469. @item @code{snippet} (default: @code{#f})
  5470. A G-expression (@pxref{G-Expressions}) or S-expression that will be run
  5471. in the source directory. This is a convenient way to modify the source,
  5472. sometimes more convenient than a patch.
  5473. @item @code{patch-flags} (default: @code{'("-p1")})
  5474. A list of command-line flags that should be passed to the @code{patch}
  5475. command.
  5476. @item @code{patch-inputs} (default: @code{#f})
  5477. Input packages or derivations to the patching process. When this is
  5478. @code{#f}, the usual set of inputs necessary for patching are provided,
  5479. such as GNU@tie{}Patch.
  5480. @item @code{modules} (default: @code{'()})
  5481. A list of Guile modules that should be loaded during the patching
  5482. process and while running the code in the @code{snippet} field.
  5483. @item @code{patch-guile} (default: @code{#f})
  5484. The Guile package that should be used in the patching process. When
  5485. this is @code{#f}, a sensible default is used.
  5486. @end table
  5487. @end deftp
  5488. @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
  5489. Construct a content hash object for the given @var{algorithm}, and with
  5490. @var{value} as its hash value. When @var{algorithm} is omitted, assume
  5491. it is @code{sha256}.
  5492. @var{value} can be a literal string, in which case it is base32-decoded,
  5493. or it can be a bytevector.
  5494. The following forms are all equivalent:
  5495. @lisp
  5496. (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
  5497. (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
  5498. sha256)
  5499. (content-hash (base32
  5500. "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
  5501. (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
  5502. sha256)
  5503. @end lisp
  5504. Technically, @code{content-hash} is currently implemented as a macro.
  5505. It performs sanity checks at macro-expansion time, when possible, such
  5506. as ensuring that @var{value} has the right size for @var{algorithm}.
  5507. @end deftp
  5508. As we have seen above, how exactly the data an origin refers to is
  5509. retrieved is determined by its @code{method} field. The @code{(guix
  5510. download)} module provides the most common method, @code{url-fetch},
  5511. described below.
  5512. @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
  5513. [name] [#:executable? #f]
  5514. Return a fixed-output derivation that fetches data from @var{url} (a
  5515. string, or a list of strings denoting alternate URLs), which is expected
  5516. to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
  5517. the file name is the base name of URL; optionally, @var{name} can
  5518. specify a different file name. When @var{executable?} is true, make the
  5519. downloaded file executable.
  5520. When one of the URL starts with @code{mirror://}, then its host part is
  5521. interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
  5522. Alternatively, when URL starts with @code{file://}, return the
  5523. corresponding file name in the store.
  5524. @end deffn
  5525. Likewise, the @code{(guix git-download)} module defines the
  5526. @code{git-fetch} origin method, which fetches data from a Git version
  5527. control repository, and the @code{git-reference} data type to describe
  5528. the repository and revision to fetch.
  5529. @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
  5530. Return a fixed-output derivation that fetches @var{ref}, a
  5531. @code{<git-reference>} object. The output is expected to have recursive
  5532. hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
  5533. the file name, or a generic name if @code{#f}.
  5534. @end deffn
  5535. @deftp {Data Type} git-reference
  5536. This data type represents a Git reference for @code{git-fetch} to
  5537. retrieve.
  5538. @table @asis
  5539. @item @code{url}
  5540. The URL of the Git repository to clone.
  5541. @item @code{commit}
  5542. This string denotes either the commit to fetch (a hexadecimal string,
  5543. either the full SHA1 commit or a ``short'' commit string; the latter is
  5544. not recommended) or the tag to fetch.
  5545. @item @code{recursive?} (default: @code{#f})
  5546. This Boolean indicates whether to recursively fetch Git sub-modules.
  5547. @end table
  5548. The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
  5549. repository:
  5550. @lisp
  5551. (git-reference
  5552. (url "https://git.savannah.gnu.org/git/hello.git")
  5553. (commit "v2.10"))
  5554. @end lisp
  5555. This is equivalent to the reference below, which explicitly names the
  5556. commit:
  5557. @lisp
  5558. (git-reference
  5559. (url "https://git.savannah.gnu.org/git/hello.git")
  5560. (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
  5561. @end lisp
  5562. @end deftp
  5563. For Mercurial repositories, the module @code{(guix hg-download)} defines
  5564. the @code{hg-fetch} origin method and @code{hg-reference} data type for
  5565. support of the Mercurial version control system.
  5566. @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
  5567. [name]
  5568. Return a fixed-output derivation that fetches @var{ref}, a
  5569. @code{<hg-reference>} object. The output is expected to have recursive
  5570. hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
  5571. the file name, or a generic name if @code{#false}.
  5572. @end deffn
  5573. @node Defining Package Variants
  5574. @section Defining Package Variants
  5575. @cindex customizing packages
  5576. @cindex variants, of packages
  5577. One of the nice things with Guix is that, given a package definition,
  5578. you can easily @emph{derive} variants of that package---for a different
  5579. upstream version, with different dependencies, different compilation
  5580. options, and so on. Some of these custom packages can be defined
  5581. straight from the command line (@pxref{Package Transformation Options}).
  5582. This section describes how to define package variants in code. This can
  5583. be useful in ``manifests'' (@pxref{profile-manifest,
  5584. @option{--manifest}}) and in your own package collection
  5585. (@pxref{Creating a Channel}), among others!
  5586. @cindex inherit, for package definitions
  5587. As discussed earlier, packages are first-class objects in the Scheme
  5588. language. The @code{(guix packages)} module provides the @code{package}
  5589. construct to define new package objects (@pxref{package Reference}).
  5590. The easiest way to define a package variant is using the @code{inherit}
  5591. keyword together with @code{package}. This allows you to inherit from a
  5592. package definition while overriding the fields you want.
  5593. For example, given the @code{hello} variable, which contains a
  5594. definition for the current version of GNU@tie{}Hello, here's how you
  5595. would define a variant for version 2.2 (released in 2006, it's
  5596. vintage!):
  5597. @lisp
  5598. (use-modules (gnu packages base)) ;for 'hello'
  5599. (define hello-2.2
  5600. (package
  5601. (inherit hello)
  5602. (version "2.2")
  5603. (source (origin
  5604. (method url-fetch)
  5605. (uri (string-append "mirror://gnu/hello/hello-" version
  5606. ".tar.gz"))
  5607. (sha256
  5608. (base32
  5609. "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
  5610. @end lisp
  5611. The example above corresponds to what the @option{--with-source} package
  5612. transformation option does. Essentially @code{hello-2.2} preserves all
  5613. the fields of @code{hello}, except @code{version} and @code{source},
  5614. which it overrides. Note that the original @code{hello} variable is
  5615. still there, in the @code{(gnu packages base)} module, unchanged. When
  5616. you define a custom package like this, you are really @emph{adding} a
  5617. new package definition; the original one remains available.
  5618. You can just as well define variants with a different set of
  5619. dependencies than the original package. For example, the default
  5620. @code{gdb} package depends on @code{guile}, but since that is an
  5621. optional dependency, you can define a variant that removes that
  5622. dependency like so:
  5623. @lisp
  5624. (use-modules (gnu packages gdb) ;for 'gdb'
  5625. (srfi srfi-1)) ;for 'alist-delete'
  5626. (define gdb-sans-guile
  5627. (package
  5628. (inherit gdb)
  5629. (inputs (alist-delete "guile"
  5630. (package-inputs gdb)))))
  5631. @end lisp
  5632. The @code{alist-delete} call above removes the tuple from the
  5633. @code{inputs} field that has @code{"guile"} as its first element
  5634. (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
  5635. Manual}).
  5636. In some cases, you may find it useful to write functions
  5637. (``procedures'', in Scheme parlance) that return a package based on some
  5638. parameters. For example, consider the @code{luasocket} library for the
  5639. Lua programming language. We want to create @code{luasocket} packages
  5640. for major versions of Lua. One way to do that is to define a procedure
  5641. that takes a Lua package and returns a @code{luasocket} package that
  5642. depends on it:
  5643. @lisp
  5644. (define (make-lua-socket name lua)
  5645. ;; Return a luasocket package built with LUA.
  5646. (package
  5647. (name name)
  5648. (version "3.0")
  5649. ;; several fields omitted
  5650. (inputs
  5651. `(("lua" ,lua)))
  5652. (synopsis "Socket library for Lua")))
  5653. (define-public lua5.1-socket
  5654. (make-lua-socket "lua5.1-socket" lua-5.1))
  5655. (define-public lua5.2-socket
  5656. (make-lua-socket "lua5.2-socket" lua-5.2))
  5657. @end lisp
  5658. Here we have defined packages @code{lua5.1-socket} and
  5659. @code{lua5.2-socket} by calling @code{make-lua-socket} with different
  5660. arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
  5661. more info on procedures. Having top-level public definitions for these
  5662. two packages means that they can be referred to from the command line
  5663. (@pxref{Package Modules}).
  5664. @cindex package transformations
  5665. These are pretty simple package variants. As a convenience, the
  5666. @code{(guix transformations)} module provides a high-level interface
  5667. that directly maps to the more sophisticated package transformation
  5668. options (@pxref{Package Transformation Options}):
  5669. @deffn {Scheme Procedure} options->transformation @var{opts}
  5670. Return a procedure that, when passed an object to build (package,
  5671. derivation, etc.), applies the transformations specified by @var{opts} and returns
  5672. the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
  5673. @lisp
  5674. ((with-branch . "guile-gcrypt=master")
  5675. (without-tests . "libgcrypt"))
  5676. @end lisp
  5677. Each symbol names a transformation and the corresponding string is an argument
  5678. to that transformation.
  5679. @end deffn
  5680. For instance, a manifest equivalent to this command:
  5681. @example
  5682. guix build guix \
  5683. --with-branch=guile-gcrypt=master \
  5684. --with-debug-info=zlib
  5685. @end example
  5686. @noindent
  5687. ... would look like this:
  5688. @lisp
  5689. (use-modules (guix transformations))
  5690. (define transform
  5691. ;; The package transformation procedure.
  5692. (options->transformation
  5693. '((with-branch . "guile-gcrypt=master")
  5694. (with-debug-info . "zlib"))))
  5695. (packages->manifest
  5696. (list (transform (specification->package "guix"))))
  5697. @end lisp
  5698. @cindex input rewriting
  5699. @cindex dependency graph rewriting
  5700. The @code{options->transformation} procedure is convenient, but it's
  5701. perhaps also not as flexible as you may like. How is it implemented?
  5702. The astute reader probably noticed that most package transformation
  5703. options go beyond the superficial changes shown in the first examples of
  5704. this section: they involve @dfn{input rewriting}, whereby the dependency
  5705. graph of a package is rewritten by replacing specific inputs by others.
  5706. Dependency graph rewriting, for the purposes of swapping packages in the
  5707. graph, is what the @code{package-input-rewriting} procedure in
  5708. @code{(guix packages)} implements.
  5709. @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
  5710. [@var{rewrite-name}] [#:deep? #t]
  5711. Return a procedure that, when passed a package, replaces its direct and
  5712. indirect dependencies, including implicit inputs when @var{deep?} is
  5713. true, according to @var{replacements}. @var{replacements} is a list of
  5714. package pairs; the first element of each pair is the package to replace,
  5715. and the second one is the replacement.
  5716. Optionally, @var{rewrite-name} is a one-argument procedure that takes
  5717. the name of a package and returns its new name after rewrite.
  5718. @end deffn
  5719. @noindent
  5720. Consider this example:
  5721. @lisp
  5722. (define libressl-instead-of-openssl
  5723. ;; This is a procedure to replace OPENSSL by LIBRESSL,
  5724. ;; recursively.
  5725. (package-input-rewriting `((,openssl . ,libressl))))
  5726. (define git-with-libressl
  5727. (libressl-instead-of-openssl git))
  5728. @end lisp
  5729. @noindent
  5730. Here we first define a rewriting procedure that replaces @var{openssl}
  5731. with @var{libressl}. Then we use it to define a @dfn{variant} of the
  5732. @var{git} package that uses @var{libressl} instead of @var{openssl}.
  5733. This is exactly what the @option{--with-input} command-line option does
  5734. (@pxref{Package Transformation Options, @option{--with-input}}).
  5735. The following variant of @code{package-input-rewriting} can match packages to
  5736. be replaced by name rather than by identity.
  5737. @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
  5738. Return a procedure that, given a package, applies the given
  5739. @var{replacements} to all the package graph, including implicit inputs
  5740. unless @var{deep?} is false. @var{replacements} is a list of
  5741. spec/procedures pair; each spec is a package specification such as
  5742. @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
  5743. package and returns a replacement for that package.
  5744. @end deffn
  5745. The example above could be rewritten this way:
  5746. @lisp
  5747. (define libressl-instead-of-openssl
  5748. ;; Replace all the packages called "openssl" with LibreSSL.
  5749. (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
  5750. @end lisp
  5751. The key difference here is that, this time, packages are matched by spec and
  5752. not by identity. In other words, any package in the graph that is called
  5753. @code{openssl} will be replaced.
  5754. A more generic procedure to rewrite a package dependency graph is
  5755. @code{package-mapping}: it supports arbitrary changes to nodes in the
  5756. graph.
  5757. @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
  5758. Return a procedure that, given a package, applies @var{proc} to all the packages
  5759. depended on and returns the resulting package. The procedure stops recursion
  5760. when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
  5761. applied to implicit inputs as well.
  5762. @end deffn
  5763. @node Build Systems
  5764. @section Build Systems
  5765. @cindex build system
  5766. Each package definition specifies a @dfn{build system} and arguments for
  5767. that build system (@pxref{Defining Packages}). This @code{build-system}
  5768. field represents the build procedure of the package, as well as implicit
  5769. dependencies of that build procedure.
  5770. Build systems are @code{<build-system>} objects. The interface to
  5771. create and manipulate them is provided by the @code{(guix build-system)}
  5772. module, and actual build systems are exported by specific modules.
  5773. @cindex bag (low-level package representation)
  5774. Under the hood, build systems first compile package objects to
  5775. @dfn{bags}. A @dfn{bag} is like a package, but with less
  5776. ornamentation---in other words, a bag is a lower-level representation of
  5777. a package, which includes all the inputs of that package, including some
  5778. that were implicitly added by the build system. This intermediate
  5779. representation is then compiled to a derivation (@pxref{Derivations}).
  5780. The @code{package-with-c-toolchain} is an example of a way to change the
  5781. implicit inputs that a package's build system pulls in (@pxref{package
  5782. Reference, @code{package-with-c-toolchain}}).
  5783. Build systems accept an optional list of @dfn{arguments}. In package
  5784. definitions, these are passed @i{via} the @code{arguments} field
  5785. (@pxref{Defining Packages}). They are typically keyword arguments
  5786. (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
  5787. Guile Reference Manual}). The value of these arguments is usually
  5788. evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
  5789. by the daemon (@pxref{Derivations}).
  5790. The main build system is @code{gnu-build-system}, which implements the
  5791. standard build procedure for GNU and many other packages. It
  5792. is provided by the @code{(guix build-system gnu)} module.
  5793. @defvr {Scheme Variable} gnu-build-system
  5794. @code{gnu-build-system} represents the GNU Build System, and variants
  5795. thereof (@pxref{Configuration, configuration and makefile conventions,,
  5796. standards, GNU Coding Standards}).
  5797. @cindex build phases
  5798. In a nutshell, packages using it are configured, built, and installed with
  5799. the usual @code{./configure && make && make check && make install}
  5800. command sequence. In practice, a few additional steps are often needed.
  5801. All these steps are split up in separate @dfn{phases},
  5802. notably@footnote{Please see the @code{(guix build gnu-build-system)}
  5803. modules for more details about the build phases.}:
  5804. @table @code
  5805. @item unpack
  5806. Unpack the source tarball, and change the current directory to the
  5807. extracted source tree. If the source is actually a directory, copy it
  5808. to the build tree, and enter that directory.
  5809. @item patch-source-shebangs
  5810. Patch shebangs encountered in source files so they refer to the right
  5811. store file names. For instance, this changes @code{#!/bin/sh} to
  5812. @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
  5813. @item configure
  5814. Run the @file{configure} script with a number of default options, such
  5815. as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
  5816. by the @code{#:configure-flags} argument.
  5817. @item build
  5818. Run @code{make} with the list of flags specified with
  5819. @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
  5820. (the default), build with @code{make -j}.
  5821. @item check
  5822. Run @code{make check}, or some other target specified with
  5823. @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
  5824. @code{#:parallel-tests?} argument is true (the default), run @code{make
  5825. check -j}.
  5826. @item install
  5827. Run @code{make install} with the flags listed in @code{#:make-flags}.
  5828. @item patch-shebangs
  5829. Patch shebangs on the installed executable files.
  5830. @item strip
  5831. Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
  5832. is false), copying them to the @code{debug} output when available
  5833. (@pxref{Installing Debugging Files}).
  5834. @end table
  5835. @vindex %standard-phases
  5836. The build-side module @code{(guix build gnu-build-system)} defines
  5837. @code{%standard-phases} as the default list of build phases.
  5838. @code{%standard-phases} is a list of symbol/procedure pairs, where the
  5839. procedure implements the actual phase.
  5840. @xref{Build Phases}, for more info on build phases and ways to customize
  5841. them.
  5842. In addition, this build system ensures that the ``standard'' environment
  5843. for GNU packages is available. This includes tools such as GCC, libc,
  5844. Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
  5845. build-system gnu)} module for a complete list). We call these the
  5846. @dfn{implicit inputs} of a package, because package definitions do not
  5847. have to mention them.
  5848. @end defvr
  5849. Other @code{<build-system>} objects are defined to support other
  5850. conventions and tools used by free software packages. They inherit most
  5851. of @code{gnu-build-system}, and differ mainly in the set of inputs
  5852. implicitly added to the build process, and in the list of phases
  5853. executed. Some of these build systems are listed below.
  5854. @defvr {Scheme Variable} ant-build-system
  5855. This variable is exported by @code{(guix build-system ant)}. It
  5856. implements the build procedure for Java packages that can be built with
  5857. @url{https://ant.apache.org/, Ant build tool}.
  5858. It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
  5859. provided by the @code{icedtea} package to the set of inputs. Different
  5860. packages can be specified with the @code{#:ant} and @code{#:jdk}
  5861. parameters, respectively.
  5862. When the original package does not provide a suitable Ant build file,
  5863. the parameter @code{#:jar-name} can be used to generate a minimal Ant
  5864. build file @file{build.xml} with tasks to build the specified jar
  5865. archive. In this case the parameter @code{#:source-dir} can be used to
  5866. specify the source sub-directory, defaulting to ``src''.
  5867. The @code{#:main-class} parameter can be used with the minimal ant
  5868. buildfile to specify the main class of the resulting jar. This makes the
  5869. jar file executable. The @code{#:test-include} parameter can be used to
  5870. specify the list of junit tests to run. It defaults to
  5871. @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
  5872. disable some tests. It defaults to @code{(list "**/Abstract*.java")},
  5873. because abstract classes cannot be run as tests.
  5874. The parameter @code{#:build-target} can be used to specify the Ant task
  5875. that should be run during the @code{build} phase. By default the
  5876. ``jar'' task will be run.
  5877. @end defvr
  5878. @defvr {Scheme Variable} android-ndk-build-system
  5879. @cindex Android distribution
  5880. @cindex Android NDK build system
  5881. This variable is exported by @code{(guix build-system android-ndk)}. It
  5882. implements a build procedure for Android NDK (native development kit)
  5883. packages using a Guix-specific build process.
  5884. The build system assumes that packages install their public interface
  5885. (header) files to the subdirectory @file{include} of the @code{out} output and
  5886. their libraries to the subdirectory @file{lib} the @code{out} output.
  5887. It's also assumed that the union of all the dependencies of a package
  5888. has no conflicting files.
  5889. For the time being, cross-compilation is not supported - so right now
  5890. the libraries and header files are assumed to be host tools.
  5891. @end defvr
  5892. @defvr {Scheme Variable} asdf-build-system/source
  5893. @defvrx {Scheme Variable} asdf-build-system/sbcl
  5894. @defvrx {Scheme Variable} asdf-build-system/ecl
  5895. These variables, exported by @code{(guix build-system asdf)}, implement
  5896. build procedures for Common Lisp packages using
  5897. @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
  5898. definition facility for Common Lisp programs and libraries.
  5899. The @code{asdf-build-system/source} system installs the packages in
  5900. source form, and can be loaded using any common lisp implementation, via
  5901. ASDF@. The others, such as @code{asdf-build-system/sbcl}, install binary
  5902. systems in the format which a particular implementation understands.
  5903. These build systems can also be used to produce executable programs, or
  5904. lisp images which contain a set of packages pre-loaded.
  5905. The build system uses naming conventions. For binary packages, the
  5906. package name should be prefixed with the lisp implementation, such as
  5907. @code{sbcl-} for @code{asdf-build-system/sbcl}.
  5908. Additionally, the corresponding source package should be labeled using
  5909. the same convention as python packages (see @ref{Python Modules}), using
  5910. the @code{cl-} prefix.
  5911. In order to create executable programs and images, the build-side
  5912. procedures @code{build-program} and @code{build-image} can be used.
  5913. They should be called in a build phase after the
  5914. @code{create-asdf-configuration} phase, so that the system which was
  5915. just built can be used within the resulting image. @code{build-program}
  5916. requires a list of Common Lisp expressions to be passed as the
  5917. @code{#:entry-program} argument.
  5918. By default, all the @file{.asd} files present in the sources are read to
  5919. find system definitions. The @code{#:asd-files} parameter can be used
  5920. to specify the list of @file{.asd} files to read. Furthermore, if the
  5921. package defines a system for its tests in a separate file, it will be
  5922. loaded before the tests are run if it is specified by the
  5923. @code{#:test-asd-file} parameter. If it is not set, the files
  5924. @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
  5925. and @code{test.asd} will be tried if they exist.
  5926. If for some reason the package must be named in a different way than the
  5927. naming conventions suggest, or if several systems must be compiled, the
  5928. @code{#:asd-systems} parameter can be used to specify the list of system
  5929. names.
  5930. @end defvr
  5931. @defvr {Scheme Variable} cargo-build-system
  5932. @cindex Rust programming language
  5933. @cindex Cargo (Rust build system)
  5934. This variable is exported by @code{(guix build-system cargo)}. It
  5935. supports builds of packages using Cargo, the build tool of the
  5936. @uref{https://www.rust-lang.org, Rust programming language}.
  5937. It adds @code{rustc} and @code{cargo} to the set of inputs.
  5938. A different Rust package can be specified with the @code{#:rust} parameter.
  5939. Regular cargo dependencies should be added to the package definition via the
  5940. @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
  5941. spec can be a package or a source definition. Note that the spec must
  5942. evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
  5943. file at its root, or it will be ignored. Similarly, cargo dev-dependencies
  5944. should be added to the package definition via the
  5945. @code{#:cargo-development-inputs} parameter.
  5946. In its @code{configure} phase, this build system will make any source inputs
  5947. specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
  5948. parameters available to cargo. It will also remove an included
  5949. @code{Cargo.lock} file to be recreated by @code{cargo} during the
  5950. @code{build} phase. The @code{install} phase installs the binaries
  5951. defined by the crate.
  5952. @end defvr
  5953. @defvr {Scheme Variable} chicken-build-system
  5954. This variable is exported by @code{(guix build-system chicken)}. It
  5955. builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
  5956. ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
  5957. gets compiled by a C compiler, in this case GCC.
  5958. This build system adds @code{chicken} to the package inputs, as well as
  5959. the packages of @code{gnu-build-system}.
  5960. The build system can't (yet) deduce the egg's name automatically, so just like
  5961. with @code{go-build-system} and its @code{#:import-path}, you should define
  5962. @code{#:egg-name} in the package's @code{arguments} field.
  5963. For example, if you are packaging the @code{srfi-1} egg:
  5964. @lisp
  5965. (arguments '(#:egg-name "srfi-1"))
  5966. @end lisp
  5967. Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
  5968. because CHICKEN doesn't embed absolute references in compiled eggs.
  5969. Test dependencies should go to @code{native-inputs}, as usual.
  5970. @end defvr
  5971. @defvr {Scheme Variable} copy-build-system
  5972. This variable is exported by @code{(guix build-system copy)}. It
  5973. supports builds of simple packages that don't require much compiling,
  5974. mostly just moving files around.
  5975. It adds much of the @code{gnu-build-system} packages to the set of
  5976. inputs. Because of this, the @code{copy-build-system} does not require
  5977. all the boilerplate code often needed for the
  5978. @code{trivial-build-system}.
  5979. To further simplify the file installation process, an
  5980. @code{#:install-plan} argument is exposed to let the packager specify
  5981. which files go where. The install plan is a list of @code{(@var{source}
  5982. @var{target} [@var{filters}])}. @var{filters} are optional.
  5983. @itemize
  5984. @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
  5985. @itemize
  5986. @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
  5987. @item Otherwise install @var{source} as @var{target}.
  5988. @end itemize
  5989. @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
  5990. the trailing slash of @var{target} is implied with the same meaning
  5991. as above.
  5992. @itemize
  5993. @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
  5994. @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
  5995. @code{#:exclude-regexp}, only select files are installed depending on
  5996. the filters. Each filters is specified by a list of strings.
  5997. @itemize
  5998. @item With @code{#:include}, install all the files which the path suffix matches
  5999. at least one of the elements in the given list.
  6000. @item With @code{#:include-regexp}, install all the files which the
  6001. subpaths match at least one of the regular expressions in the given
  6002. list.
  6003. @item The @code{#:exclude} and @code{#:exclude-regexp} filters
  6004. are the complement of their inclusion counterpart. Without @code{#:include} flags,
  6005. install all files but those matching the exclusion filters.
  6006. If both inclusions and exclusions are specified, the exclusions are done
  6007. on top of the inclusions.
  6008. @end itemize
  6009. @end itemize
  6010. In all cases, the paths relative to @var{source} are preserved within
  6011. @var{target}.
  6012. @end itemize
  6013. Examples:
  6014. @itemize
  6015. @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
  6016. @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
  6017. @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
  6018. e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
  6019. @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
  6020. @file{share/my-app/sub/file}.
  6021. @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
  6022. @file{share/my-app/file}.
  6023. @end itemize
  6024. @end defvr
  6025. @cindex Clojure (programming language)
  6026. @cindex simple Clojure build system
  6027. @defvr {Scheme Variable} clojure-build-system
  6028. This variable is exported by @code{(guix build-system clojure)}. It implements
  6029. a simple build procedure for @uref{https://clojure.org/, Clojure} packages
  6030. using plain old @code{compile} in Clojure. Cross-compilation is not supported
  6031. yet.
  6032. It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
  6033. Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
  6034. @code{#:zip} parameters, respectively.
  6035. A list of source directories, test directories and jar names can be specified
  6036. with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
  6037. parameters, respectively. Compile directory and main class can be specified
  6038. with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
  6039. Other parameters are documented below.
  6040. This build system is an extension of @code{ant-build-system}, but with the
  6041. following phases changed:
  6042. @table @code
  6043. @item build
  6044. This phase calls @code{compile} in Clojure to compile source files and runs
  6045. @command{jar} to create jars from both source files and compiled files
  6046. according to the include list and exclude list specified in
  6047. @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
  6048. has priority over the include list. These lists consist of symbols
  6049. representing Clojure libraries or the special keyword @code{#:all} representing
  6050. all Clojure libraries found under the source directories. The parameter
  6051. @code{#:omit-source?} decides if source should be included into the jars.
  6052. @item check
  6053. This phase runs tests according to the include list and exclude list specified
  6054. in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
  6055. meanings are analogous to that of @code{#:aot-include} and
  6056. @code{#:aot-exclude}, except that the special keyword @code{#:all} now
  6057. stands for all Clojure libraries found under the test directories. The
  6058. parameter @code{#:tests?} decides if tests should be run.
  6059. @item install
  6060. This phase installs all jars built previously.
  6061. @end table
  6062. Apart from the above, this build system also contains an additional phase:
  6063. @table @code
  6064. @item install-doc
  6065. This phase installs all top-level files with base name matching
  6066. @code{%doc-regex}. A different regex can be specified with the
  6067. @code{#:doc-regex} parameter. All files (recursively) inside the documentation
  6068. directories specified in @code{#:doc-dirs} are installed as well.
  6069. @end table
  6070. @end defvr
  6071. @defvr {Scheme Variable} cmake-build-system
  6072. This variable is exported by @code{(guix build-system cmake)}. It
  6073. implements the build procedure for packages using the
  6074. @url{https://www.cmake.org, CMake build tool}.
  6075. It automatically adds the @code{cmake} package to the set of inputs.
  6076. Which package is used can be specified with the @code{#:cmake}
  6077. parameter.
  6078. The @code{#:configure-flags} parameter is taken as a list of flags
  6079. passed to the @command{cmake} command. The @code{#:build-type}
  6080. parameter specifies in abstract terms the flags passed to the compiler;
  6081. it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
  6082. debugging information''), which roughly means that code is compiled with
  6083. @code{-O2 -g}, as is the case for Autoconf-based packages by default.
  6084. @end defvr
  6085. @defvr {Scheme Variable} dune-build-system
  6086. This variable is exported by @code{(guix build-system dune)}. It
  6087. supports builds of packages using @uref{https://dune.build/, Dune}, a build
  6088. tool for the OCaml programming language. It is implemented as an extension
  6089. of the @code{ocaml-build-system} which is described below. As such, the
  6090. @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
  6091. system.
  6092. It automatically adds the @code{dune} package to the set of inputs.
  6093. Which package is used can be specified with the @code{#:dune}
  6094. parameter.
  6095. There is no @code{configure} phase because dune packages typically don't
  6096. need to be configured. The @code{#:build-flags} parameter is taken as a
  6097. list of flags passed to the @code{dune} command during the build.
  6098. The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
  6099. command instead of the more recent @code{dune} command while building
  6100. a package. Its default value is @code{#f}.
  6101. The @code{#:package} parameter can be passed to specify a package name, which
  6102. is useful when a package contains multiple packages and you want to build
  6103. only one of them. This is equivalent to passing the @code{-p} argument to
  6104. @code{dune}.
  6105. @end defvr
  6106. @defvr {Scheme Variable} go-build-system
  6107. This variable is exported by @code{(guix build-system go)}. It
  6108. implements a build procedure for Go packages using the standard
  6109. @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
  6110. Go build mechanisms}.
  6111. The user is expected to provide a value for the key @code{#:import-path}
  6112. and, in some cases, @code{#:unpack-path}. The
  6113. @url{https://golang.org/doc/code.html#ImportPaths, import path}
  6114. corresponds to the file system path expected by the package's build
  6115. scripts and any referring packages, and provides a unique way to
  6116. refer to a Go package. It is typically based on a combination of the
  6117. package source code's remote URI and file system hierarchy structure. In
  6118. some cases, you will need to unpack the package's source code to a
  6119. different directory structure than the one indicated by the import path,
  6120. and @code{#:unpack-path} should be used in such cases.
  6121. Packages that provide Go libraries should install their source code into
  6122. the built output. The key @code{#:install-source?}, which defaults to
  6123. @code{#t}, controls whether or not the source code is installed. It can
  6124. be set to @code{#f} for packages that only provide executable files.
  6125. @end defvr
  6126. @defvr {Scheme Variable} glib-or-gtk-build-system
  6127. This variable is exported by @code{(guix build-system glib-or-gtk)}. It
  6128. is intended for use with packages making use of GLib or GTK+.
  6129. This build system adds the following two phases to the ones defined by
  6130. @code{gnu-build-system}:
  6131. @table @code
  6132. @item glib-or-gtk-wrap
  6133. The phase @code{glib-or-gtk-wrap} ensures that programs in
  6134. @file{bin/} are able to find GLib ``schemas'' and
  6135. @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
  6136. modules}. This is achieved by wrapping the programs in launch scripts
  6137. that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
  6138. environment variables.
  6139. It is possible to exclude specific package outputs from that wrapping
  6140. process by listing their names in the
  6141. @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
  6142. when an output is known not to contain any GLib or GTK+ binaries, and
  6143. where wrapping would gratuitously add a dependency of that output on
  6144. GLib and GTK+.
  6145. @item glib-or-gtk-compile-schemas
  6146. The phase @code{glib-or-gtk-compile-schemas} makes sure that all
  6147. @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
  6148. GSettings schemas} of GLib are compiled. Compilation is performed by the
  6149. @command{glib-compile-schemas} program. It is provided by the package
  6150. @code{glib:bin} which is automatically imported by the build system.
  6151. The @code{glib} package providing @command{glib-compile-schemas} can be
  6152. specified with the @code{#:glib} parameter.
  6153. @end table
  6154. Both phases are executed after the @code{install} phase.
  6155. @end defvr
  6156. @defvr {Scheme Variable} guile-build-system
  6157. This build system is for Guile packages that consist exclusively of Scheme
  6158. code and that are so lean that they don't even have a makefile, let alone a
  6159. @file{configure} script. It compiles Scheme code using @command{guild
  6160. compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
  6161. installs the @file{.scm} and @file{.go} files in the right place. It also
  6162. installs documentation.
  6163. This build system supports cross-compilation by using the
  6164. @option{--target} option of @samp{guild compile}.
  6165. Packages built with @code{guile-build-system} must provide a Guile package in
  6166. their @code{native-inputs} field.
  6167. @end defvr
  6168. @defvr {Scheme Variable} julia-build-system
  6169. This variable is exported by @code{(guix build-system julia)}. It
  6170. implements the build procedure used by @uref{https://julialang.org/,
  6171. julia} packages, which essentially is similar to running @samp{julia -e
  6172. 'using Pkg; Pkg.add(package)'} in an environment where
  6173. @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
  6174. Tests are run with @code{Pkg.test}.
  6175. Julia packages require the source @code{file-name} to be the real name of the
  6176. package, correctly capitalized.
  6177. For packages requiring shared library dependencies, you may need to write the
  6178. @file{/deps/deps.jl} file manually. It's usually a line of @code{const
  6179. variable = /gnu/store/library.so} for each dependency, plus a void function
  6180. @code{check_deps() = nothing}.
  6181. Some older packages that aren't using @file{Package.toml} yet, will require
  6182. this file to be created, too. The function @code{julia-create-package-toml}
  6183. helps creating the file. You need to pass the outputs and the source of the
  6184. package, it's name (the same as the @code{file-name} parameter), the package
  6185. uuid, the package version, and a list of dependencies specified by their name
  6186. and their uuid.
  6187. @end defvr
  6188. @defvr {Scheme Variable} maven-build-system
  6189. This variable is exported by @code{(guix build-system maven)}. It implements
  6190. a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
  6191. is a dependency and lifecycle management tool for Java. A user of Maven
  6192. specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
  6193. When Maven does not have one of the dependencies or plugins in its repository,
  6194. it will download them and use them to build the package.
  6195. The maven build system ensures that maven will not try to download any
  6196. dependency by running in offline mode. Maven will fail if a dependency is
  6197. missing. Before running Maven, the @file{pom.xml} (and subprojects) are
  6198. modified to specify the version of dependencies and plugins that match the
  6199. versions available in the guix build environment. Dependencies and plugins
  6200. must be installed in the fake maven repository at @file{lib/m2}, and are
  6201. symlinked into a proper repository before maven is run. Maven is instructed
  6202. to use that repository for the build and installs built artifacts there.
  6203. Changed files are copied to the @file{lib/m2} directory of the package output.
  6204. You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
  6205. or let the build system use the default @file{pom.xml} file in the sources.
  6206. In case you need to specify a dependency's version manually, you can use the
  6207. @code{#:local-packages} argument. It takes an association list where the key
  6208. is the groupId of the package and its value is an association list where the
  6209. key is the artifactId of the package and its value is the version you want to
  6210. override in the @file{pom.xml}.
  6211. Some packages use dependencies or plugins that are not useful at runtime nor
  6212. at build time in Guix. You can alter the @file{pom.xml} file to remove them
  6213. using the @code{#:exclude} argument. Its value is an association list where
  6214. the key is the groupId of the plugin or dependency you want to remove, and
  6215. the value is a list of artifactId you want to remove.
  6216. You can override the default @code{jdk} and @code{maven} packages with the
  6217. corresponding argument, @code{#:jdk} and @code{#:maven}.
  6218. The @code{#:maven-plugins} argument is a list of maven plugins used during
  6219. the build, with the same format as the @code{inputs} fields of the package
  6220. declaration. Its default value is @code{(default-maven-plugins)} which is
  6221. also exported.
  6222. @end defvr
  6223. @defvr {Scheme Variable} minify-build-system
  6224. This variable is exported by @code{(guix build-system minify)}. It
  6225. implements a minification procedure for simple JavaScript packages.
  6226. It adds @code{uglify-js} to the set of inputs and uses it to compress
  6227. all JavaScript files in the @file{src} directory. A different minifier
  6228. package can be specified with the @code{#:uglify-js} parameter, but it
  6229. is expected that the package writes the minified code to the standard
  6230. output.
  6231. When the input JavaScript files are not all located in the @file{src}
  6232. directory, the parameter @code{#:javascript-files} can be used to
  6233. specify a list of file names to feed to the minifier.
  6234. @end defvr
  6235. @defvr {Scheme Variable} ocaml-build-system
  6236. This variable is exported by @code{(guix build-system ocaml)}. It implements
  6237. a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
  6238. of choosing the correct set of commands to run for each package. OCaml
  6239. packages can expect many different commands to be run. This build system will
  6240. try some of them.
  6241. When the package has a @file{setup.ml} file present at the top-level, it will
  6242. run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
  6243. @code{ocaml setup.ml -install}. The build system will assume that this file
  6244. was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
  6245. care of setting the prefix and enabling tests if they are not disabled. You
  6246. can pass configure and build flags with the @code{#:configure-flags} and
  6247. @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
  6248. set of flags used to enable tests. The @code{#:use-make?} key can be used to
  6249. bypass this system in the build and install phases.
  6250. When the package has a @file{configure} file, it is assumed that it is a
  6251. hand-made configure script that requires a different argument format than
  6252. in the @code{gnu-build-system}. You can add more flags with the
  6253. @code{#:configure-flags} key.
  6254. When the package has a @file{Makefile} file (or @code{#:use-make?} is
  6255. @code{#t}), it will be used and more flags can be passed to the build and
  6256. install phases with the @code{#:make-flags} key.
  6257. Finally, some packages do not have these files and use a somewhat standard
  6258. location for its build system. In that case, the build system will run
  6259. @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
  6260. providing the path to the required findlib module. Additional flags can
  6261. be passed via the @code{#:build-flags} key. Install is taken care of by
  6262. @command{opam-installer}. In this case, the @code{opam} package must
  6263. be added to the @code{native-inputs} field of the package definition.
  6264. Note that most OCaml packages assume they will be installed in the same
  6265. directory as OCaml, which is not what we want in guix. In particular, they
  6266. will install @file{.so} files in their module's directory, which is usually
  6267. fine because it is in the OCaml compiler directory. In guix though, these
  6268. libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
  6269. variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
  6270. @file{.so} libraries should be installed.
  6271. @end defvr
  6272. @defvr {Scheme Variable} python-build-system
  6273. This variable is exported by @code{(guix build-system python)}. It
  6274. implements the more or less standard build procedure used by Python
  6275. packages, which consists in running @code{python setup.py build} and
  6276. then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
  6277. For packages that install stand-alone Python programs under @code{bin/},
  6278. it takes care of wrapping these programs so that their @env{PYTHONPATH}
  6279. environment variable points to all the Python libraries they depend on.
  6280. Which Python package is used to perform the build can be specified with
  6281. the @code{#:python} parameter. This is a useful way to force a package
  6282. to be built for a specific version of the Python interpreter, which
  6283. might be necessary if the package is only compatible with a single
  6284. interpreter version.
  6285. By default guix calls @code{setup.py} under control of
  6286. @code{setuptools}, much like @command{pip} does. Some packages are not
  6287. compatible with setuptools (and pip), thus you can disable this by
  6288. setting the @code{#:use-setuptools?} parameter to @code{#f}.
  6289. @end defvr
  6290. @defvr {Scheme Variable} perl-build-system
  6291. This variable is exported by @code{(guix build-system perl)}. It
  6292. implements the standard build procedure for Perl packages, which either
  6293. consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
  6294. followed by @code{Build} and @code{Build install}; or in running
  6295. @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
  6296. @code{make} and @code{make install}, depending on which of
  6297. @code{Build.PL} or @code{Makefile.PL} is present in the package
  6298. distribution. Preference is given to the former if both @code{Build.PL}
  6299. and @code{Makefile.PL} exist in the package distribution. This
  6300. preference can be reversed by specifying @code{#t} for the
  6301. @code{#:make-maker?} parameter.
  6302. The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
  6303. passes flags specified by the @code{#:make-maker-flags} or
  6304. @code{#:module-build-flags} parameter, respectively.
  6305. Which Perl package is used can be specified with @code{#:perl}.
  6306. @end defvr
  6307. @defvr {Scheme Variable} qt-build-system
  6308. This variable is exported by @code{(guix build-system qt)}. It
  6309. is intended for use with applications using Qt or KDE.
  6310. This build system adds the following two phases to the ones defined by
  6311. @code{cmake-build-system}:
  6312. @table @code
  6313. @item check-setup
  6314. The phase @code{check-setup} prepares the environment for running
  6315. the checks as commonly used by Qt test programs.
  6316. For now this only sets some environment variables:
  6317. @code{QT_QPA_PLATFORM=offscreen},
  6318. @code{DBUS_FATAL_WARNINGS=0} and
  6319. @code{CTEST_OUTPUT_ON_FAILURE=1}.
  6320. This phase is added before the @code{check} phase.
  6321. It's a separate phase to ease adjusting if necessary.
  6322. @item qt-wrap
  6323. The phase @code{qt-wrap}
  6324. searches for Qt5 plugin paths, QML paths and some XDG in the inputs
  6325. and output. In case some path is found, all programs in the output's
  6326. @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
  6327. are wrapped in scripts defining the necessary environment variables.
  6328. It is possible to exclude specific package outputs from that wrapping process
  6329. by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
  6330. This is useful when an output is known not to contain any Qt binaries, and
  6331. where wrapping would gratuitously add a dependency of that output on Qt, KDE,
  6332. or such.
  6333. This phase is added after the @code{install} phase.
  6334. @end table
  6335. @end defvr
  6336. @defvr {Scheme Variable} r-build-system
  6337. This variable is exported by @code{(guix build-system r)}. It
  6338. implements the build procedure used by @uref{https://r-project.org, R}
  6339. packages, which essentially is little more than running @samp{R CMD
  6340. INSTALL --library=/gnu/store/@dots{}} in an environment where
  6341. @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
  6342. run after installation using the R function
  6343. @code{tools::testInstalledPackage}.
  6344. @end defvr
  6345. @defvr {Scheme Variable} rakudo-build-system
  6346. This variable is exported by @code{(guix build-system rakudo)}. It
  6347. implements the build procedure used by @uref{https://rakudo.org/,
  6348. Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
  6349. package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
  6350. installs the binaries, library files and the resources, as well as wrap
  6351. the files under the @code{bin/} directory. Tests can be skipped by
  6352. passing @code{#f} to the @code{tests?} parameter.
  6353. Which rakudo package is used can be specified with @code{rakudo}.
  6354. Which perl6-tap-harness package used for the tests can be specified with
  6355. @code{#:prove6} or removed by passing @code{#f} to the
  6356. @code{with-prove6?} parameter.
  6357. Which perl6-zef package used for tests and installing can be specified
  6358. with @code{#:zef} or removed by passing @code{#f} to the
  6359. @code{with-zef?} parameter.
  6360. @end defvr
  6361. @defvr {Scheme Variable} texlive-build-system
  6362. This variable is exported by @code{(guix build-system texlive)}. It is
  6363. used to build TeX packages in batch mode with a specified engine. The
  6364. build system sets the @env{TEXINPUTS} variable to find all TeX source
  6365. files in the inputs.
  6366. By default it runs @code{luatex} on all files ending on @code{ins}. A
  6367. different engine and format can be specified with the
  6368. @code{#:tex-format} argument. Different build targets can be specified
  6369. with the @code{#:build-targets} argument, which expects a list of file
  6370. names. The build system adds only @code{texlive-bin} and
  6371. @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
  6372. inputs. Both can be overridden with the arguments @code{#:texlive-bin}
  6373. and @code{#:texlive-latex-base}, respectively.
  6374. The @code{#:tex-directory} parameter tells the build system where to
  6375. install the built files under the texmf tree.
  6376. @end defvr
  6377. @defvr {Scheme Variable} ruby-build-system
  6378. This variable is exported by @code{(guix build-system ruby)}. It
  6379. implements the RubyGems build procedure used by Ruby packages, which
  6380. involves running @code{gem build} followed by @code{gem install}.
  6381. The @code{source} field of a package that uses this build system
  6382. typically references a gem archive, since this is the format that Ruby
  6383. developers use when releasing their software. The build system unpacks
  6384. the gem archive, potentially patches the source, runs the test suite,
  6385. repackages the gem, and installs it. Additionally, directories and
  6386. tarballs may be referenced to allow building unreleased gems from Git or
  6387. a traditional source release tarball.
  6388. Which Ruby package is used can be specified with the @code{#:ruby}
  6389. parameter. A list of additional flags to be passed to the @command{gem}
  6390. command can be specified with the @code{#:gem-flags} parameter.
  6391. @end defvr
  6392. @defvr {Scheme Variable} waf-build-system
  6393. This variable is exported by @code{(guix build-system waf)}. It
  6394. implements a build procedure around the @code{waf} script. The common
  6395. phases---@code{configure}, @code{build}, and @code{install}---are
  6396. implemented by passing their names as arguments to the @code{waf}
  6397. script.
  6398. The @code{waf} script is executed by the Python interpreter. Which
  6399. Python package is used to run the script can be specified with the
  6400. @code{#:python} parameter.
  6401. @end defvr
  6402. @defvr {Scheme Variable} scons-build-system
  6403. This variable is exported by @code{(guix build-system scons)}. It
  6404. implements the build procedure used by the SCons software construction
  6405. tool. This build system runs @code{scons} to build the package,
  6406. @code{scons test} to run tests, and then @code{scons install} to install
  6407. the package.
  6408. Additional flags to be passed to @code{scons} can be specified with the
  6409. @code{#:scons-flags} parameter. The default build and install targets
  6410. can be overridden with @code{#:build-targets} and
  6411. @code{#:install-targets} respectively. The version of Python used to
  6412. run SCons can be specified by selecting the appropriate SCons package
  6413. with the @code{#:scons} parameter.
  6414. @end defvr
  6415. @defvr {Scheme Variable} haskell-build-system
  6416. This variable is exported by @code{(guix build-system haskell)}. It
  6417. implements the Cabal build procedure used by Haskell packages, which
  6418. involves running @code{runhaskell Setup.hs configure
  6419. --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
  6420. Instead of installing the package by running @code{runhaskell Setup.hs
  6421. install}, to avoid trying to register libraries in the read-only
  6422. compiler store directory, the build system uses @code{runhaskell
  6423. Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
  6424. addition, the build system generates the package documentation by
  6425. running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
  6426. is passed. Optional Haddock parameters can be passed with the help of
  6427. the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
  6428. not found, the build system looks for @code{Setup.lhs} instead.
  6429. Which Haskell compiler is used can be specified with the @code{#:haskell}
  6430. parameter which defaults to @code{ghc}.
  6431. @end defvr
  6432. @defvr {Scheme Variable} dub-build-system
  6433. This variable is exported by @code{(guix build-system dub)}. It
  6434. implements the Dub build procedure used by D packages, which
  6435. involves running @code{dub build} and @code{dub run}.
  6436. Installation is done by copying the files manually.
  6437. Which D compiler is used can be specified with the @code{#:ldc}
  6438. parameter which defaults to @code{ldc}.
  6439. @end defvr
  6440. @anchor{emacs-build-system}
  6441. @defvr {Scheme Variable} emacs-build-system
  6442. This variable is exported by @code{(guix build-system emacs)}. It
  6443. implements an installation procedure similar to the packaging system
  6444. of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
  6445. It first creates the @code{@code{package}-autoloads.el} file, then it
  6446. byte compiles all Emacs Lisp files. Differently from the Emacs
  6447. packaging system, the Info documentation files are moved to the standard
  6448. documentation directory and the @file{dir} file is deleted. The Elisp
  6449. package files are installed directly under @file{share/emacs/site-lisp}.
  6450. @end defvr
  6451. @defvr {Scheme Variable} font-build-system
  6452. This variable is exported by @code{(guix build-system font)}. It
  6453. implements an installation procedure for font packages where upstream
  6454. provides pre-compiled TrueType, OpenType, etc.@: font files that merely
  6455. need to be copied into place. It copies font files to standard
  6456. locations in the output directory.
  6457. @end defvr
  6458. @defvr {Scheme Variable} meson-build-system
  6459. This variable is exported by @code{(guix build-system meson)}. It
  6460. implements the build procedure for packages that use
  6461. @url{https://mesonbuild.com, Meson} as their build system.
  6462. It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
  6463. of inputs, and they can be changed with the parameters @code{#:meson}
  6464. and @code{#:ninja} if needed. The default Meson is
  6465. @code{meson-for-build}, which is special because it doesn't clear the
  6466. @code{RUNPATH} of binaries and libraries when they are installed.
  6467. This build system is an extension of @code{gnu-build-system}, but with the
  6468. following phases changed to some specific for Meson:
  6469. @table @code
  6470. @item configure
  6471. The phase runs @code{meson} with the flags specified in
  6472. @code{#:configure-flags}. The flag @option{--buildtype} is always set to
  6473. @code{debugoptimized} unless something else is specified in
  6474. @code{#:build-type}.
  6475. @item build
  6476. The phase runs @code{ninja} to build the package in parallel by default, but
  6477. this can be changed with @code{#:parallel-build?}.
  6478. @item check
  6479. The phase runs @code{ninja} with the target specified in @code{#:test-target},
  6480. which is @code{"test"} by default.
  6481. @item install
  6482. The phase runs @code{ninja install} and can not be changed.
  6483. @end table
  6484. Apart from that, the build system also adds the following phases:
  6485. @table @code
  6486. @item fix-runpath
  6487. This phase ensures that all binaries can find the libraries they need.
  6488. It searches for required libraries in subdirectories of the package being
  6489. built, and adds those to @code{RUNPATH} where needed. It also removes
  6490. references to libraries left over from the build phase by
  6491. @code{meson-for-build}, such as test dependencies, that aren't actually
  6492. required for the program to run.
  6493. @item glib-or-gtk-wrap
  6494. This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
  6495. is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
  6496. @item glib-or-gtk-compile-schemas
  6497. This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
  6498. is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
  6499. @end table
  6500. @end defvr
  6501. @defvr {Scheme Variable} linux-module-build-system
  6502. @code{linux-module-build-system} allows building Linux kernel modules.
  6503. @cindex build phases
  6504. This build system is an extension of @code{gnu-build-system}, but with the
  6505. following phases changed:
  6506. @table @code
  6507. @item configure
  6508. This phase configures the environment so that the Linux kernel's Makefile
  6509. can be used to build the external kernel module.
  6510. @item build
  6511. This phase uses the Linux kernel's Makefile in order to build the external
  6512. kernel module.
  6513. @item install
  6514. This phase uses the Linux kernel's Makefile in order to install the external
  6515. kernel module.
  6516. @end table
  6517. It is possible and useful to specify the Linux kernel to use for building
  6518. the module (in the @code{arguments} form of a package using the
  6519. @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
  6520. @end defvr
  6521. @defvr {Scheme Variable} node-build-system
  6522. This variable is exported by @code{(guix build-system node)}. It
  6523. implements the build procedure used by @uref{https://nodejs.org,
  6524. Node.js}, which implements an approximation of the @code{npm install}
  6525. command, followed by an @code{npm test} command.
  6526. Which Node.js package is used to interpret the @code{npm} commands can
  6527. be specified with the @code{#:node} parameter which defaults to
  6528. @code{node}.
  6529. @end defvr
  6530. Lastly, for packages that do not need anything as sophisticated, a
  6531. ``trivial'' build system is provided. It is trivial in the sense that
  6532. it provides basically no support: it does not pull any implicit inputs,
  6533. and does not have a notion of build phases.
  6534. @defvr {Scheme Variable} trivial-build-system
  6535. This variable is exported by @code{(guix build-system trivial)}.
  6536. This build system requires a @code{#:builder} argument. This argument
  6537. must be a Scheme expression that builds the package output(s)---as
  6538. with @code{build-expression->derivation} (@pxref{Derivations,
  6539. @code{build-expression->derivation}}).
  6540. @end defvr
  6541. @node Build Phases
  6542. @section Build Phases
  6543. @cindex build phases, for packages
  6544. Almost all package build systems implement a notion @dfn{build phases}:
  6545. a sequence of actions that the build system executes, when you build the
  6546. package, leading to the installed byproducts in the store. A notable
  6547. exception is the ``bare-bones'' @code{trivial-build-system}
  6548. (@pxref{Build Systems}).
  6549. As discussed in the previous section, those build systems provide a
  6550. standard list of phases. For @code{gnu-build-system}, the standard
  6551. phases include an @code{unpack} phase to unpack the source code tarball,
  6552. a @command{configure} phase to run @code{./configure}, a @code{build}
  6553. phase to run @command{make}, and (among others) an @code{install} phase
  6554. to run @command{make install}; @pxref{Build Systems}, for a more
  6555. detailed view of these phases. Likewise, @code{cmake-build-system}
  6556. inherits these phases, but its @code{configure} phase runs
  6557. @command{cmake} instead of @command{./configure}. Other build systems,
  6558. such as @code{python-build-system}, have a wholly different list of
  6559. standard phases. All this code runs on the @dfn{build side}: it is
  6560. evaluated when you actually build the package, in a dedicated build
  6561. process spawned by the build daemon (@pxref{Invoking guix-daemon}).
  6562. Build phases are represented as association lists or ``alists''
  6563. (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
  6564. each key is a symbol for the name of the phase and the associated value
  6565. is a procedure that accepts an arbitrary number of arguments. By
  6566. convention, those procedures receive information about the build in the
  6567. form of @dfn{keyword parameters}, which they can use or ignore.
  6568. For example, here is how @code{(guix build gnu-build-system)} defines
  6569. @code{%standard-phases}, the variable holding its alist of build
  6570. phases@footnote{We present a simplified view of those build phases, but
  6571. do take a look at @code{(guix build gnu-build-system)} to see all the
  6572. details!}:
  6573. @lisp
  6574. ;; The build phases of 'gnu-build-system'.
  6575. (define* (unpack #:key source #:allow-other-keys)
  6576. ;; Extract the source tarball.
  6577. (invoke "tar" "xvf" source))
  6578. (define* (configure #:key outputs #:allow-other-keys)
  6579. ;; Run the 'configure' script. Install to output "out".
  6580. (let ((out (assoc-ref outputs "out")))
  6581. (invoke "./configure"
  6582. (string-append "--prefix=" out))))
  6583. (define* (build #:allow-other-keys)
  6584. ;; Compile.
  6585. (invoke "make"))
  6586. (define* (check #:key (test-target "check") (tests? #true)
  6587. #:allow-other-keys)
  6588. ;; Run the test suite.
  6589. (if tests?
  6590. (invoke "make" test-target)
  6591. (display "test suite not run\n")))
  6592. (define* (install #:allow-other-keys)
  6593. ;; Install files to the prefix 'configure' specified.
  6594. (invoke "make" "install"))
  6595. (define %standard-phases
  6596. ;; The list of standard phases (quite a few are omitted
  6597. ;; for brevity). Each element is a symbol/procedure pair.
  6598. (list (cons 'unpack unpack)
  6599. (cons 'configure configure)
  6600. (cons 'build build)
  6601. (cons 'check check)
  6602. (cons 'install install)))
  6603. @end lisp
  6604. This shows how @code{%standard-phases} is defined as a list of
  6605. symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
  6606. Manual}). The first pair associates the @code{unpack} procedure with
  6607. the @code{unpack} symbol---a name; the second pair defines the
  6608. @code{configure} phase similarly, and so on. When building a package
  6609. that uses @code{gnu-build-system} with its default list of phases, those
  6610. phases are executed sequentially. You can see the name of each phase
  6611. started and completed in the build log of packages that you build.
  6612. Let's now look at the procedures themselves. Each one is defined with
  6613. @code{define*}: @code{#:key} lists keyword parameters the procedure
  6614. accepts, possibly with a default value, and @code{#:allow-other-keys}
  6615. specifies that other keyword parameters are ignored (@pxref{Optional
  6616. Arguments,,, guile, GNU Guile Reference Manual}).
  6617. The @code{unpack} procedure honors the @code{source} parameter, which
  6618. the build system uses to pass the file name of the source tarball (or
  6619. version control checkout), and it ignores other parameters. The
  6620. @code{configure} phase only cares about the @code{outputs} parameter, an
  6621. alist mapping package output names to their store file name
  6622. (@pxref{Packages with Multiple Outputs}). It extracts the file name of
  6623. for @code{out}, the default output, and passes it to
  6624. @command{./configure} as the installation prefix, meaning that
  6625. @command{make install} will eventually copy all the files in that
  6626. directory (@pxref{Configuration, configuration and makefile
  6627. conventions,, standards, GNU Coding Standards}). @code{build} and
  6628. @code{install} ignore all their arguments. @code{check} honors the
  6629. @code{test-target} argument, which specifies the name of the Makefile
  6630. target to run tests; it prints a message and skips tests when
  6631. @code{tests?} is false.
  6632. @cindex build phases, customizing
  6633. The list of phases used for a particular package can be changed with the
  6634. @code{#:phases} parameter of the build system. Changing the set of
  6635. build phases boils down to building a new alist of phases based on the
  6636. @code{%standard-phases} alist described above. This can be done with
  6637. standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
  6638. Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
  6639. more convenient to do so with @code{modify-phases} (@pxref{Build
  6640. Utilities, @code{modify-phases}}).
  6641. Here is an example of a package definition that removes the
  6642. @code{configure} phase of @code{%standard-phases} and inserts a new
  6643. phase before the @code{build} phase, called
  6644. @code{set-prefix-in-makefile}:
  6645. @lisp
  6646. (define-public example
  6647. (package
  6648. (name "example")
  6649. ;; other fields omitted
  6650. (build-system gnu-build-system)
  6651. (arguments
  6652. '(#:phases (modify-phases %standard-phases
  6653. (delete 'configure)
  6654. (add-before 'build 'set-prefix-in-makefile
  6655. (lambda* (#:key outputs #:allow-other-keys)
  6656. ;; Modify the makefile so that its
  6657. ;; 'PREFIX' variable points to "out".
  6658. (let ((out (assoc-ref outputs "out")))
  6659. (substitute* "Makefile"
  6660. (("PREFIX =.*")
  6661. (string-append "PREFIX = "
  6662. out "\n")))
  6663. #true))))))))
  6664. @end lisp
  6665. The new phase that is inserted is written as an anonymous procedure,
  6666. introduced with @code{lambda*}; it honors the @code{outputs} parameter
  6667. we have seen before. @xref{Build Utilities}, for more about the helpers
  6668. used by this phase, and for more examples of @code{modify-phases}.
  6669. @cindex code staging
  6670. @cindex staging, of code
  6671. Keep in mind that build phases are code evaluated at the time the
  6672. package is actually built. This explains why the whole
  6673. @code{modify-phases} expression above is quoted (it comes after the
  6674. @code{'} or apostrophe): it is @dfn{staged} for later execution.
  6675. @xref{G-Expressions}, for an explanation of code staging and the
  6676. @dfn{code strata} involved.
  6677. @node Build Utilities
  6678. @section Build Utilities
  6679. As soon as you start writing non-trivial package definitions
  6680. (@pxref{Defining Packages}) or other build actions
  6681. (@pxref{G-Expressions}), you will likely start looking for helpers for
  6682. ``shell-like'' actions---creating directories, copying and deleting
  6683. files recursively, manipulating build phases, and so on. The
  6684. @code{(guix build utils)} module provides such utility procedures.
  6685. Most build systems load @code{(guix build utils)} (@pxref{Build
  6686. Systems}). Thus, when writing custom build phases for your package
  6687. definitions, you can usually assume those procedures are in scope.
  6688. When writing G-expressions, you can import @code{(guix build utils)} on
  6689. the ``build side'' using @code{with-imported-modules} and then put it in
  6690. scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
  6691. guile, GNU Guile Reference Manual}):
  6692. @lisp
  6693. (with-imported-modules '((guix build utils)) ;import it
  6694. (computed-file "empty-tree"
  6695. #~(begin
  6696. ;; Put it in scope.
  6697. (use-modules (guix build utils))
  6698. ;; Happily use its 'mkdir-p' procedure.
  6699. (mkdir-p (string-append #$output "/a/b/c")))))
  6700. @end lisp
  6701. The remainder of this section is the reference for most of the utility
  6702. procedures provided by @code{(guix build utils)}.
  6703. @c TODO Document what's missing.
  6704. @subsection Dealing with Store File Names
  6705. This section documents procedures that deal with store file names.
  6706. @deffn {Scheme Procedure} %store-directory
  6707. Return the directory name of the store.
  6708. @end deffn
  6709. @deffn {Scheme Procedure} store-file-name? @var{file}
  6710. Return true if @var{file} is in the store.
  6711. @end deffn
  6712. @deffn {Scheme Procedure} strip-store-file-name @var{file}
  6713. Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
  6714. The result is typically a @code{"@var{package}-@var{version}"} string.
  6715. @end deffn
  6716. @deffn {Scheme Procedure} package-name->name+version @var{name}
  6717. Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
  6718. values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
  6719. unavailable, @var{name} and @code{#f} are returned. The first hyphen
  6720. followed by a digit is considered to introduce the version part.
  6721. @end deffn
  6722. @subsection File Types
  6723. The procedures below deal with files and file types.
  6724. @deffn {Scheme Procedure} directory-exists? @var{dir}
  6725. Return @code{#t} if @var{dir} exists and is a directory.
  6726. @end deffn
  6727. @deffn {Scheme Procedure} executable-file? @var{file}
  6728. Return @code{#t} if @var{file} exists and is executable.
  6729. @end deffn
  6730. @deffn {Scheme Procedure} symbolic-link? @var{file}
  6731. Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
  6732. @end deffn
  6733. @deffn {Scheme Procedure} elf-file? @var{file}
  6734. @deffnx {Scheme Procedure} ar-file? @var{file}
  6735. @deffnx {Scheme Procedure} gzip-file? @var{file}
  6736. Return @code{#t} if @var{file} is, respectively, an ELF file, an
  6737. @code{ar} archive (such as a @file{.a} static library), or a gzip file.
  6738. @end deffn
  6739. @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
  6740. If @var{file} is a gzip file, reset its embedded timestamp (as with
  6741. @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
  6742. When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
  6743. @end deffn
  6744. @subsection File Manipulation
  6745. The following procedures and macros help create, modify, and delete
  6746. files. They provide functionality comparable to common shell utilities
  6747. such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
  6748. @command{sed}. They complement Guile's extensive, but low-level, file
  6749. system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
  6750. @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
  6751. Run @var{body} with @var{directory} as the process's current directory.
  6752. Essentially, this macro changes the current directory to @var{directory}
  6753. before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
  6754. guile, GNU Guile Reference Manual}). It changes back to the initial
  6755. directory when the dynamic extent of @var{body} is left, be it @i{via}
  6756. normal procedure return or @i{via} a non-local exit such as an
  6757. exception.
  6758. @end deffn
  6759. @deffn {Scheme Procedure} mkdir-p @var{dir}
  6760. Create directory @var{dir} and all its ancestors.
  6761. @end deffn
  6762. @deffn {Scheme Procedure} install-file @var{file} @var{directory}
  6763. Create @var{directory} if it does not exist and copy @var{file} in there
  6764. under the same name.
  6765. @end deffn
  6766. @deffn {Scheme Procedure} make-file-writable @var{file}
  6767. Make @var{file} writable for its owner.
  6768. @end deffn
  6769. @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
  6770. [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
  6771. Copy @var{source} directory to @var{destination}. Follow symlinks if
  6772. @var{follow-symlinks?} is true; otherwise, just preserve them. When
  6773. @var{keep-mtime?} is true, keep the modification time of the files in
  6774. @var{source} on those of @var{destination}. Write verbose output to the
  6775. @var{log} port.
  6776. @end deffn
  6777. @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
  6778. [#:follow-mounts? #f]
  6779. Delete @var{dir} recursively, like @command{rm -rf}, without following
  6780. symlinks. Don't follow mount points either, unless @var{follow-mounts?}
  6781. is true. Report but ignore errors.
  6782. @end deffn
  6783. @deffn {Scheme Syntax} substitute* @var{file} @
  6784. ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
  6785. Substitute @var{regexp} in @var{file} by the string returned by
  6786. @var{body}. @var{body} is evaluated with each @var{match-var} bound to
  6787. the corresponding positional regexp sub-expression. For example:
  6788. @lisp
  6789. (substitute* file
  6790. (("hello")
  6791. "good morning\n")
  6792. (("foo([a-z]+)bar(.*)$" all letters end)
  6793. (string-append "baz" letter end)))
  6794. @end lisp
  6795. Here, anytime a line of @var{file} contains @code{hello}, it is replaced
  6796. by @code{good morning}. Anytime a line of @var{file} matches the second
  6797. regexp, @code{all} is bound to the complete match, @code{letters} is bound
  6798. to the first sub-expression, and @code{end} is bound to the last one.
  6799. When one of the @var{match-var} is @code{_}, no variable is bound to the
  6800. corresponding match substring.
  6801. Alternatively, @var{file} may be a list of file names, in which case
  6802. they are all subject to the substitutions.
  6803. Be careful about using @code{$} to match the end of a line; by itself it
  6804. won't match the terminating newline of a line.
  6805. @end deffn
  6806. @subsection File Search
  6807. @cindex file, searching
  6808. This section documents procedures to search and filter files.
  6809. @deffn {Scheme Procedure} file-name-predicate @var{regexp}
  6810. Return a predicate that returns true when passed a file name whose base
  6811. name matches @var{regexp}.
  6812. @end deffn
  6813. @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
  6814. [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
  6815. Return the lexicographically sorted list of files under @var{dir} for
  6816. which @var{pred} returns true. @var{pred} is passed two arguments: the
  6817. absolute file name, and its stat buffer; the default predicate always
  6818. returns true. @var{pred} can also be a regular expression, in which
  6819. case it is equivalent to @code{(file-name-predicate @var{pred})}.
  6820. @var{stat} is used to obtain file information; using @code{lstat} means
  6821. that symlinks are not followed. If @var{directories?} is true, then
  6822. directories will also be included. If @var{fail-on-error?} is true,
  6823. raise an exception upon error.
  6824. @end deffn
  6825. Here are a few examples where we assume that the current directory is
  6826. the root of the Guix source tree:
  6827. @lisp
  6828. ;; List all the regular files in the current directory.
  6829. (find-files ".")
  6830. @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
  6831. ;; List all the .scm files under gnu/services.
  6832. (find-files "gnu/services" "\\.scm$")
  6833. @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
  6834. ;; List ar files in the current directory.
  6835. (find-files "." (lambda (file stat) (ar-file? file)))
  6836. @result{} ("./libformat.a" "./libstore.a" @dots{})
  6837. @end lisp
  6838. @deffn {Scheme Procedure} which @var{program}
  6839. Return the complete file name for @var{program} as found in
  6840. @code{$PATH}, or @code{#f} if @var{program} could not be found.
  6841. @end deffn
  6842. @subsection Build Phases
  6843. @cindex build phases
  6844. The @code{(guix build utils)} also contains tools to manipulate build
  6845. phases as used by build systems (@pxref{Build Systems}). Build phases
  6846. are represented as association lists or ``alists'' (@pxref{Association
  6847. Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
  6848. naming the phase and the associated value is a procedure (@pxref{Build
  6849. Phases}).
  6850. Guile core and the @code{(srfi srfi-1)} module both provide tools to
  6851. manipulate alists. The @code{(guix build utils)} module complements
  6852. those with tools written with build phases in mind.
  6853. @cindex build phases, modifying
  6854. @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
  6855. Modify @var{phases} sequentially as per each @var{clause}, which may
  6856. have one of the following forms:
  6857. @lisp
  6858. (delete @var{old-phase-name})
  6859. (replace @var{old-phase-name} @var{new-phase})
  6860. (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
  6861. (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
  6862. @end lisp
  6863. Where every @var{phase-name} above is an expression evaluating to a
  6864. symbol, and @var{new-phase} an expression evaluating to a procedure.
  6865. @end deffn
  6866. The example below is taken from the definition of the @code{grep}
  6867. package. It adds a phase to run after the @code{install} phase, called
  6868. @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
  6869. is for anonymous procedures) that takes a @code{#:outputs} keyword
  6870. argument and ignores extra keyword arguments (@pxref{Optional
  6871. Arguments,,, guile, GNU Guile Reference Manual}, for more on
  6872. @code{lambda*} and optional and keyword arguments.) The phase uses
  6873. @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
  6874. scripts so that they refer to @code{grep} by its absolute file name:
  6875. @lisp
  6876. (modify-phases %standard-phases
  6877. (add-after 'install 'fix-egrep-and-fgrep
  6878. ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
  6879. ;; absolute file name instead of searching for it in $PATH.
  6880. (lambda* (#:key outputs #:allow-other-keys)
  6881. (let* ((out (assoc-ref outputs "out"))
  6882. (bin (string-append out "/bin")))
  6883. (substitute* (list (string-append bin "/egrep")
  6884. (string-append bin "/fgrep"))
  6885. (("^exec grep")
  6886. (string-append "exec " bin "/grep")))
  6887. #t))))
  6888. @end lisp
  6889. In the example below, phases are modified in two ways: the standard
  6890. @code{configure} phase is deleted, presumably because the package does
  6891. not have a @file{configure} script or anything similar, and the default
  6892. @code{install} phase is replaced by one that manually copies the
  6893. executable files to be installed:
  6894. @lisp
  6895. (modify-phases %standard-phases
  6896. (delete 'configure) ;no 'configure' script
  6897. (replace 'install
  6898. (lambda* (#:key outputs #:allow-other-keys)
  6899. ;; The package's Makefile doesn't provide an "install"
  6900. ;; rule so do it by ourselves.
  6901. (let ((bin (string-append (assoc-ref outputs "out")
  6902. "/bin")))
  6903. (install-file "footswitch" bin)
  6904. (install-file "scythe" bin)
  6905. #t))))
  6906. @end lisp
  6907. @c TODO: Add more examples.
  6908. @node The Store
  6909. @section The Store
  6910. @cindex store
  6911. @cindex store items
  6912. @cindex store paths
  6913. Conceptually, the @dfn{store} is the place where derivations that have
  6914. been built successfully are stored---by default, @file{/gnu/store}.
  6915. Sub-directories in the store are referred to as @dfn{store items} or
  6916. sometimes @dfn{store paths}. The store has an associated database that
  6917. contains information such as the store paths referred to by each store
  6918. path, and the list of @emph{valid} store items---results of successful
  6919. builds. This database resides in @file{@var{localstatedir}/guix/db},
  6920. where @var{localstatedir} is the state directory specified @i{via}
  6921. @option{--localstatedir} at configure time, usually @file{/var}.
  6922. The store is @emph{always} accessed by the daemon on behalf of its clients
  6923. (@pxref{Invoking guix-daemon}). To manipulate the store, clients
  6924. connect to the daemon over a Unix-domain socket, send requests to it,
  6925. and read the result---these are remote procedure calls, or RPCs.
  6926. @quotation Note
  6927. Users must @emph{never} modify files under @file{/gnu/store} directly.
  6928. This would lead to inconsistencies and break the immutability
  6929. assumptions of Guix's functional model (@pxref{Introduction}).
  6930. @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
  6931. how to check the integrity of the store and attempt recovery from
  6932. accidental modifications.
  6933. @end quotation
  6934. The @code{(guix store)} module provides procedures to connect to the
  6935. daemon, and to perform RPCs. These are described below. By default,
  6936. @code{open-connection}, and thus all the @command{guix} commands,
  6937. connect to the local daemon or to the URI specified by the
  6938. @env{GUIX_DAEMON_SOCKET} environment variable.
  6939. @defvr {Environment Variable} GUIX_DAEMON_SOCKET
  6940. When set, the value of this variable should be a file name or a URI
  6941. designating the daemon endpoint. When it is a file name, it denotes a
  6942. Unix-domain socket to connect to. In addition to file names, the
  6943. supported URI schemes are:
  6944. @table @code
  6945. @item file
  6946. @itemx unix
  6947. These are for Unix-domain sockets.
  6948. @code{file:///var/guix/daemon-socket/socket} is equivalent to
  6949. @file{/var/guix/daemon-socket/socket}.
  6950. @item guix
  6951. @cindex daemon, remote access
  6952. @cindex remote access to the daemon
  6953. @cindex daemon, cluster setup
  6954. @cindex clusters, daemon setup
  6955. These URIs denote connections over TCP/IP, without encryption nor
  6956. authentication of the remote host. The URI must specify the host name
  6957. and optionally a port number (by default port 44146 is used):
  6958. @example
  6959. guix://master.guix.example.org:1234
  6960. @end example
  6961. This setup is suitable on local networks, such as clusters, where only
  6962. trusted nodes may connect to the build daemon at
  6963. @code{master.guix.example.org}.
  6964. The @option{--listen} option of @command{guix-daemon} can be used to
  6965. instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
  6966. @option{--listen}}).
  6967. @item ssh
  6968. @cindex SSH access to build daemons
  6969. These URIs allow you to connect to a remote daemon over SSH@. This
  6970. feature requires Guile-SSH (@pxref{Requirements}) and a working
  6971. @command{guile} binary in @env{PATH} on the destination machine. It
  6972. supports public key and GSSAPI authentication. A typical URL might look
  6973. like this:
  6974. @example
  6975. ssh://charlie@@guix.example.org:22
  6976. @end example
  6977. As for @command{guix copy}, the usual OpenSSH client configuration files
  6978. are honored (@pxref{Invoking guix copy}).
  6979. @end table
  6980. Additional URI schemes may be supported in the future.
  6981. @c XXX: Remove this note when the protocol incurs fewer round trips
  6982. @c and when (guix derivations) no longer relies on file system access.
  6983. @quotation Note
  6984. The ability to connect to remote build daemons is considered
  6985. experimental as of @value{VERSION}. Please get in touch with us to
  6986. share any problems or suggestions you may have (@pxref{Contributing}).
  6987. @end quotation
  6988. @end defvr
  6989. @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
  6990. Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
  6991. @var{reserve-space?} is true, instruct it to reserve a little bit of
  6992. extra space on the file system so that the garbage collector can still
  6993. operate should the disk become full. Return a server object.
  6994. @var{file} defaults to @code{%default-socket-path}, which is the normal
  6995. location given the options that were passed to @command{configure}.
  6996. @end deffn
  6997. @deffn {Scheme Procedure} close-connection @var{server}
  6998. Close the connection to @var{server}.
  6999. @end deffn
  7000. @defvr {Scheme Variable} current-build-output-port
  7001. This variable is bound to a SRFI-39 parameter, which refers to the port
  7002. where build and error logs sent by the daemon should be written.
  7003. @end defvr
  7004. Procedures that make RPCs all take a server object as their first
  7005. argument.
  7006. @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
  7007. @cindex invalid store items
  7008. Return @code{#t} when @var{path} designates a valid store item and
  7009. @code{#f} otherwise (an invalid item may exist on disk but still be
  7010. invalid, for instance because it is the result of an aborted or failed
  7011. build).
  7012. A @code{&store-protocol-error} condition is raised if @var{path} is not
  7013. prefixed by the store directory (@file{/gnu/store}).
  7014. @end deffn
  7015. @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
  7016. Add @var{text} under file @var{name} in the store, and return its store
  7017. path. @var{references} is the list of store paths referred to by the
  7018. resulting store path.
  7019. @end deffn
  7020. @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
  7021. [@var{mode}]
  7022. Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
  7023. file names, or derivation/output pairs, using the specified
  7024. @var{mode}---@code{(build-mode normal)} by default.
  7025. @end deffn
  7026. Note that the @code{(guix monads)} module provides a monad as well as
  7027. monadic versions of the above procedures, with the goal of making it
  7028. more convenient to work with code that accesses the store (@pxref{The
  7029. Store Monad}).
  7030. @c FIXME
  7031. @i{This section is currently incomplete.}
  7032. @node Derivations
  7033. @section Derivations
  7034. @cindex derivations
  7035. Low-level build actions and the environment in which they are performed
  7036. are represented by @dfn{derivations}. A derivation contains the
  7037. following pieces of information:
  7038. @itemize
  7039. @item
  7040. The outputs of the derivation---derivations produce at least one file or
  7041. directory in the store, but may produce more.
  7042. @item
  7043. @cindex build-time dependencies
  7044. @cindex dependencies, build-time
  7045. The inputs of the derivations---i.e., its build-time dependencies---which may
  7046. be other derivations or plain files in the store (patches, build scripts,
  7047. etc.).
  7048. @item
  7049. The system type targeted by the derivation---e.g., @code{x86_64-linux}.
  7050. @item
  7051. The file name of a build script in the store, along with the arguments
  7052. to be passed.
  7053. @item
  7054. A list of environment variables to be defined.
  7055. @end itemize
  7056. @cindex derivation path
  7057. Derivations allow clients of the daemon to communicate build actions to
  7058. the store. They exist in two forms: as an in-memory representation,
  7059. both on the client- and daemon-side, and as files in the store whose
  7060. name end in @file{.drv}---these files are referred to as @dfn{derivation
  7061. paths}. Derivations paths can be passed to the @code{build-derivations}
  7062. procedure to perform the build actions they prescribe (@pxref{The
  7063. Store}).
  7064. @cindex fixed-output derivations
  7065. Operations such as file downloads and version-control checkouts for
  7066. which the expected content hash is known in advance are modeled as
  7067. @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
  7068. of a fixed-output derivation are independent of its inputs---e.g., a
  7069. source code download produces the same result regardless of the download
  7070. method and tools being used.
  7071. @cindex references
  7072. @cindex run-time dependencies
  7073. @cindex dependencies, run-time
  7074. The outputs of derivations---i.e., the build results---have a set of
  7075. @dfn{references}, as reported by the @code{references} RPC or the
  7076. @command{guix gc --references} command (@pxref{Invoking guix gc}). References
  7077. are the set of run-time dependencies of the build results. References are a
  7078. subset of the inputs of the derivation; this subset is automatically computed
  7079. by the build daemon by scanning all the files in the outputs.
  7080. The @code{(guix derivations)} module provides a representation of
  7081. derivations as Scheme objects, along with procedures to create and
  7082. otherwise manipulate derivations. The lowest-level primitive to create
  7083. a derivation is the @code{derivation} procedure:
  7084. @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
  7085. @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
  7086. [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
  7087. [#:system (%current-system)] [#:references-graphs #f] @
  7088. [#:allowed-references #f] [#:disallowed-references #f] @
  7089. [#:leaked-env-vars #f] [#:local-build? #f] @
  7090. [#:substitutable? #t] [#:properties '()]
  7091. Build a derivation with the given arguments, and return the resulting
  7092. @code{<derivation>} object.
  7093. When @var{hash} and @var{hash-algo} are given, a
  7094. @dfn{fixed-output derivation} is created---i.e., one whose result is
  7095. known in advance, such as a file download. If, in addition,
  7096. @var{recursive?} is true, then that fixed output may be an executable
  7097. file or a directory and @var{hash} must be the hash of an archive
  7098. containing this output.
  7099. When @var{references-graphs} is true, it must be a list of file
  7100. name/store path pairs. In that case, the reference graph of each store
  7101. path is exported in the build environment in the corresponding file, in
  7102. a simple text format.
  7103. When @var{allowed-references} is true, it must be a list of store items
  7104. or outputs that the derivation's output may refer to. Likewise,
  7105. @var{disallowed-references}, if true, must be a list of things the
  7106. outputs may @emph{not} refer to.
  7107. When @var{leaked-env-vars} is true, it must be a list of strings
  7108. denoting environment variables that are allowed to ``leak'' from the
  7109. daemon's environment to the build environment. This is only applicable
  7110. to fixed-output derivations---i.e., when @var{hash} is true. The main
  7111. use is to allow variables such as @code{http_proxy} to be passed to
  7112. derivations that download files.
  7113. When @var{local-build?} is true, declare that the derivation is not a
  7114. good candidate for offloading and should rather be built locally
  7115. (@pxref{Daemon Offload Setup}). This is the case for small derivations
  7116. where the costs of data transfers would outweigh the benefits.
  7117. When @var{substitutable?} is false, declare that substitutes of the
  7118. derivation's output should not be used (@pxref{Substitutes}). This is
  7119. useful, for instance, when building packages that capture details of the
  7120. host CPU instruction set.
  7121. @var{properties} must be an association list describing ``properties'' of the
  7122. derivation. It is kept as-is, uninterpreted, in the derivation.
  7123. @end deffn
  7124. @noindent
  7125. Here's an example with a shell script as its builder, assuming
  7126. @var{store} is an open connection to the daemon, and @var{bash} points
  7127. to a Bash executable in the store:
  7128. @lisp
  7129. (use-modules (guix utils)
  7130. (guix store)
  7131. (guix derivations))
  7132. (let ((builder ; add the Bash script to the store
  7133. (add-text-to-store store "my-builder.sh"
  7134. "echo hello world > $out\n" '())))
  7135. (derivation store "foo"
  7136. bash `("-e" ,builder)
  7137. #:inputs `((,bash) (,builder))
  7138. #:env-vars '(("HOME" . "/homeless"))))
  7139. @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
  7140. @end lisp
  7141. As can be guessed, this primitive is cumbersome to use directly. A
  7142. better approach is to write build scripts in Scheme, of course! The
  7143. best course of action for that is to write the build code as a
  7144. ``G-expression'', and to pass it to @code{gexp->derivation}. For more
  7145. information, @pxref{G-Expressions}.
  7146. Once upon a time, @code{gexp->derivation} did not exist and constructing
  7147. derivations with build code written in Scheme was achieved with
  7148. @code{build-expression->derivation}, documented below. This procedure
  7149. is now deprecated in favor of the much nicer @code{gexp->derivation}.
  7150. @deffn {Scheme Procedure} build-expression->derivation @var{store} @
  7151. @var{name} @var{exp} @
  7152. [#:system (%current-system)] [#:inputs '()] @
  7153. [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
  7154. [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
  7155. [#:references-graphs #f] [#:allowed-references #f] @
  7156. [#:disallowed-references #f] @
  7157. [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
  7158. Return a derivation that executes Scheme expression @var{exp} as a
  7159. builder for derivation @var{name}. @var{inputs} must be a list of
  7160. @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
  7161. @code{"out"} is assumed. @var{modules} is a list of names of Guile
  7162. modules from the current search path to be copied in the store,
  7163. compiled, and made available in the load path during the execution of
  7164. @var{exp}---e.g., @code{((guix build utils) (guix build
  7165. gnu-build-system))}.
  7166. @var{exp} is evaluated in an environment where @code{%outputs} is bound
  7167. to a list of output/path pairs, and where @code{%build-inputs} is bound
  7168. to a list of string/output-path pairs made from @var{inputs}.
  7169. Optionally, @var{env-vars} is a list of string pairs specifying the name
  7170. and value of environment variables visible to the builder. The builder
  7171. terminates by passing the result of @var{exp} to @code{exit}; thus, when
  7172. @var{exp} returns @code{#f}, the build is considered to have failed.
  7173. @var{exp} is built using @var{guile-for-build} (a derivation). When
  7174. @var{guile-for-build} is omitted or is @code{#f}, the value of the
  7175. @code{%guile-for-build} fluid is used instead.
  7176. See the @code{derivation} procedure for the meaning of
  7177. @var{references-graphs}, @var{allowed-references},
  7178. @var{disallowed-references}, @var{local-build?}, and
  7179. @var{substitutable?}.
  7180. @end deffn
  7181. @noindent
  7182. Here's an example of a single-output derivation that creates a directory
  7183. containing one file:
  7184. @lisp
  7185. (let ((builder '(let ((out (assoc-ref %outputs "out")))
  7186. (mkdir out) ; create /gnu/store/@dots{}-goo
  7187. (call-with-output-file (string-append out "/test")
  7188. (lambda (p)
  7189. (display '(hello guix) p))))))
  7190. (build-expression->derivation store "goo" builder))
  7191. @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
  7192. @end lisp
  7193. @node The Store Monad
  7194. @section The Store Monad
  7195. @cindex monad
  7196. The procedures that operate on the store described in the previous
  7197. sections all take an open connection to the build daemon as their first
  7198. argument. Although the underlying model is functional, they either have
  7199. side effects or depend on the current state of the store.
  7200. The former is inconvenient: the connection to the build daemon has to be
  7201. carried around in all those functions, making it impossible to compose
  7202. functions that do not take that parameter with functions that do. The
  7203. latter can be problematic: since store operations have side effects
  7204. and/or depend on external state, they have to be properly sequenced.
  7205. @cindex monadic values
  7206. @cindex monadic functions
  7207. This is where the @code{(guix monads)} module comes in. This module
  7208. provides a framework for working with @dfn{monads}, and a particularly
  7209. useful monad for our uses, the @dfn{store monad}. Monads are a
  7210. construct that allows two things: associating ``context'' with values
  7211. (in our case, the context is the store), and building sequences of
  7212. computations (here computations include accesses to the store). Values
  7213. in a monad---values that carry this additional context---are called
  7214. @dfn{monadic values}; procedures that return such values are called
  7215. @dfn{monadic procedures}.
  7216. Consider this ``normal'' procedure:
  7217. @lisp
  7218. (define (sh-symlink store)
  7219. ;; Return a derivation that symlinks the 'bash' executable.
  7220. (let* ((drv (package-derivation store bash))
  7221. (out (derivation->output-path drv))
  7222. (sh (string-append out "/bin/bash")))
  7223. (build-expression->derivation store "sh"
  7224. `(symlink ,sh %output))))
  7225. @end lisp
  7226. Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
  7227. as a monadic function:
  7228. @lisp
  7229. (define (sh-symlink)
  7230. ;; Same, but return a monadic value.
  7231. (mlet %store-monad ((drv (package->derivation bash)))
  7232. (gexp->derivation "sh"
  7233. #~(symlink (string-append #$drv "/bin/bash")
  7234. #$output))))
  7235. @end lisp
  7236. There are several things to note in the second version: the @code{store}
  7237. parameter is now implicit and is ``threaded'' in the calls to the
  7238. @code{package->derivation} and @code{gexp->derivation} monadic
  7239. procedures, and the monadic value returned by @code{package->derivation}
  7240. is @dfn{bound} using @code{mlet} instead of plain @code{let}.
  7241. As it turns out, the call to @code{package->derivation} can even be
  7242. omitted since it will take place implicitly, as we will see later
  7243. (@pxref{G-Expressions}):
  7244. @lisp
  7245. (define (sh-symlink)
  7246. (gexp->derivation "sh"
  7247. #~(symlink (string-append #$bash "/bin/bash")
  7248. #$output)))
  7249. @end lisp
  7250. @c See
  7251. @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
  7252. @c for the funny quote.
  7253. Calling the monadic @code{sh-symlink} has no effect. As someone once
  7254. said, ``you exit a monad like you exit a building on fire: by running''.
  7255. So, to exit the monad and get the desired effect, one must use
  7256. @code{run-with-store}:
  7257. @lisp
  7258. (run-with-store (open-connection) (sh-symlink))
  7259. @result{} /gnu/store/...-sh-symlink
  7260. @end lisp
  7261. Note that the @code{(guix monad-repl)} module extends the Guile REPL with
  7262. new ``meta-commands'' to make it easier to deal with monadic procedures:
  7263. @code{run-in-store}, and @code{enter-store-monad}. The former is used
  7264. to ``run'' a single monadic value through the store:
  7265. @example
  7266. scheme@@(guile-user)> ,run-in-store (package->derivation hello)
  7267. $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
  7268. @end example
  7269. The latter enters a recursive REPL, where all the return values are
  7270. automatically run through the store:
  7271. @example
  7272. scheme@@(guile-user)> ,enter-store-monad
  7273. store-monad@@(guile-user) [1]> (package->derivation hello)
  7274. $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
  7275. store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
  7276. $3 = "/gnu/store/@dots{}-foo"
  7277. store-monad@@(guile-user) [1]> ,q
  7278. scheme@@(guile-user)>
  7279. @end example
  7280. @noindent
  7281. Note that non-monadic values cannot be returned in the
  7282. @code{store-monad} REPL.
  7283. The main syntactic forms to deal with monads in general are provided by
  7284. the @code{(guix monads)} module and are described below.
  7285. @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
  7286. Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
  7287. in @var{monad}.
  7288. @end deffn
  7289. @deffn {Scheme Syntax} return @var{val}
  7290. Return a monadic value that encapsulates @var{val}.
  7291. @end deffn
  7292. @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
  7293. @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
  7294. procedures @var{mproc}@dots{}@footnote{This operation is commonly
  7295. referred to as ``bind'', but that name denotes an unrelated procedure in
  7296. Guile. Thus we use this somewhat cryptic symbol inherited from the
  7297. Haskell language.}. There can be one @var{mproc} or several of them, as
  7298. in this example:
  7299. @lisp
  7300. (run-with-state
  7301. (with-monad %state-monad
  7302. (>>= (return 1)
  7303. (lambda (x) (return (+ 1 x)))
  7304. (lambda (x) (return (* 2 x)))))
  7305. 'some-state)
  7306. @result{} 4
  7307. @result{} some-state
  7308. @end lisp
  7309. @end deffn
  7310. @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
  7311. @var{body} ...
  7312. @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
  7313. @var{body} ...
  7314. Bind the variables @var{var} to the monadic values @var{mval} in
  7315. @var{body}, which is a sequence of expressions. As with the bind
  7316. operator, this can be thought of as ``unpacking'' the raw, non-monadic
  7317. value ``contained'' in @var{mval} and making @var{var} refer to that
  7318. raw, non-monadic value within the scope of the @var{body}. The form
  7319. (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
  7320. @var{val}, as per @code{let}. The binding operations occur in sequence
  7321. from left to right. The last expression of @var{body} must be a monadic
  7322. expression, and its result will become the result of the @code{mlet} or
  7323. @code{mlet*} when run in the @var{monad}.
  7324. @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
  7325. (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
  7326. @end deffn
  7327. @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
  7328. Bind @var{mexp} and the following monadic expressions in sequence,
  7329. returning the result of the last expression. Every expression in the
  7330. sequence must be a monadic expression.
  7331. This is akin to @code{mlet}, except that the return values of the
  7332. monadic expressions are ignored. In that sense, it is analogous to
  7333. @code{begin}, but applied to monadic expressions.
  7334. @end deffn
  7335. @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
  7336. When @var{condition} is true, evaluate the sequence of monadic
  7337. expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
  7338. @var{condition} is false, return @code{*unspecified*} in the current
  7339. monad. Every expression in the sequence must be a monadic expression.
  7340. @end deffn
  7341. @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
  7342. When @var{condition} is false, evaluate the sequence of monadic
  7343. expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
  7344. @var{condition} is true, return @code{*unspecified*} in the current
  7345. monad. Every expression in the sequence must be a monadic expression.
  7346. @end deffn
  7347. @cindex state monad
  7348. The @code{(guix monads)} module provides the @dfn{state monad}, which
  7349. allows an additional value---the state---to be @emph{threaded} through
  7350. monadic procedure calls.
  7351. @defvr {Scheme Variable} %state-monad
  7352. The state monad. Procedures in the state monad can access and change
  7353. the state that is threaded.
  7354. Consider the example below. The @code{square} procedure returns a value
  7355. in the state monad. It returns the square of its argument, but also
  7356. increments the current state value:
  7357. @lisp
  7358. (define (square x)
  7359. (mlet %state-monad ((count (current-state)))
  7360. (mbegin %state-monad
  7361. (set-current-state (+ 1 count))
  7362. (return (* x x)))))
  7363. (run-with-state (sequence %state-monad (map square (iota 3))) 0)
  7364. @result{} (0 1 4)
  7365. @result{} 3
  7366. @end lisp
  7367. When ``run'' through @code{%state-monad}, we obtain that additional state
  7368. value, which is the number of @code{square} calls.
  7369. @end defvr
  7370. @deffn {Monadic Procedure} current-state
  7371. Return the current state as a monadic value.
  7372. @end deffn
  7373. @deffn {Monadic Procedure} set-current-state @var{value}
  7374. Set the current state to @var{value} and return the previous state as a
  7375. monadic value.
  7376. @end deffn
  7377. @deffn {Monadic Procedure} state-push @var{value}
  7378. Push @var{value} to the current state, which is assumed to be a list,
  7379. and return the previous state as a monadic value.
  7380. @end deffn
  7381. @deffn {Monadic Procedure} state-pop
  7382. Pop a value from the current state and return it as a monadic value.
  7383. The state is assumed to be a list.
  7384. @end deffn
  7385. @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
  7386. Run monadic value @var{mval} starting with @var{state} as the initial
  7387. state. Return two values: the resulting value, and the resulting state.
  7388. @end deffn
  7389. The main interface to the store monad, provided by the @code{(guix
  7390. store)} module, is as follows.
  7391. @defvr {Scheme Variable} %store-monad
  7392. The store monad---an alias for @code{%state-monad}.
  7393. Values in the store monad encapsulate accesses to the store. When its
  7394. effect is needed, a value of the store monad must be ``evaluated'' by
  7395. passing it to the @code{run-with-store} procedure (see below).
  7396. @end defvr
  7397. @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
  7398. Run @var{mval}, a monadic value in the store monad, in @var{store}, an
  7399. open store connection.
  7400. @end deffn
  7401. @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
  7402. Return as a monadic value the absolute file name in the store of the file
  7403. containing @var{text}, a string. @var{references} is a list of store items that the
  7404. resulting text file refers to; it defaults to the empty list.
  7405. @end deffn
  7406. @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
  7407. Return as a monadic value the absolute file name in the store of the file
  7408. containing @var{data}, a bytevector. @var{references} is a list of store
  7409. items that the resulting binary file refers to; it defaults to the empty list.
  7410. @end deffn
  7411. @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
  7412. [#:recursive? #t] [#:select? (const #t)]
  7413. Return the name of @var{file} once interned in the store. Use
  7414. @var{name} as its store name, or the basename of @var{file} if
  7415. @var{name} is omitted.
  7416. When @var{recursive?} is true, the contents of @var{file} are added
  7417. recursively; if @var{file} designates a flat file and @var{recursive?}
  7418. is true, its contents are added, and its permission bits are kept.
  7419. When @var{recursive?} is true, call @code{(@var{select?} @var{file}
  7420. @var{stat})} for each directory entry, where @var{file} is the entry's
  7421. absolute file name and @var{stat} is the result of @code{lstat}; exclude
  7422. entries for which @var{select?} does not return true.
  7423. The example below adds a file to the store, under two different names:
  7424. @lisp
  7425. (run-with-store (open-connection)
  7426. (mlet %store-monad ((a (interned-file "README"))
  7427. (b (interned-file "README" "LEGU-MIN")))
  7428. (return (list a b))))
  7429. @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
  7430. @end lisp
  7431. @end deffn
  7432. The @code{(guix packages)} module exports the following package-related
  7433. monadic procedures:
  7434. @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
  7435. [#:system (%current-system)] [#:target #f] @
  7436. [#:output "out"]
  7437. Return as a monadic
  7438. value in the absolute file name of @var{file} within the @var{output}
  7439. directory of @var{package}. When @var{file} is omitted, return the name
  7440. of the @var{output} directory of @var{package}. When @var{target} is
  7441. true, use it as a cross-compilation target triplet.
  7442. Note that this procedure does @emph{not} build @var{package}. Thus, the
  7443. result might or might not designate an existing file. We recommend not
  7444. using this procedure unless you know what you are doing.
  7445. @end deffn
  7446. @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
  7447. @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
  7448. @var{target} [@var{system}]
  7449. Monadic version of @code{package-derivation} and
  7450. @code{package-cross-derivation} (@pxref{Defining Packages}).
  7451. @end deffn
  7452. @node G-Expressions
  7453. @section G-Expressions
  7454. @cindex G-expression
  7455. @cindex build code quoting
  7456. So we have ``derivations'', which represent a sequence of build actions
  7457. to be performed to produce an item in the store (@pxref{Derivations}).
  7458. These build actions are performed when asking the daemon to actually
  7459. build the derivations; they are run by the daemon in a container
  7460. (@pxref{Invoking guix-daemon}).
  7461. @cindex code staging
  7462. @cindex staging, of code
  7463. @cindex strata of code
  7464. It should come as no surprise that we like to write these build actions
  7465. in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
  7466. code@footnote{The term @dfn{stratum} in this context was coined by
  7467. Manuel Serrano et al.@: in the context of their work on Hop. Oleg
  7468. Kiselyov, who has written insightful
  7469. @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
  7470. on this topic}, refers to this kind of code generation as
  7471. @dfn{staging}.}: the ``host code''---code that defines packages, talks
  7472. to the daemon, etc.---and the ``build code''---code that actually
  7473. performs build actions, such as making directories, invoking
  7474. @command{make}, and so on (@pxref{Build Phases}).
  7475. To describe a derivation and its build actions, one typically needs to
  7476. embed build code inside host code. It boils down to manipulating build
  7477. code as data, and the homoiconicity of Scheme---code has a direct
  7478. representation as data---comes in handy for that. But we need more than
  7479. the normal @code{quasiquote} mechanism in Scheme to construct build
  7480. expressions.
  7481. The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
  7482. S-expressions adapted to build expressions. G-expressions, or
  7483. @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
  7484. @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
  7485. @code{#$}, and @code{#$@@}), which are comparable to
  7486. @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
  7487. respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
  7488. GNU Guile Reference Manual}). However, there are major differences:
  7489. @itemize
  7490. @item
  7491. Gexps are meant to be written to a file and run or manipulated by other
  7492. processes.
  7493. @item
  7494. When a high-level object such as a package or derivation is unquoted
  7495. inside a gexp, the result is as if its output file name had been
  7496. introduced.
  7497. @item
  7498. Gexps carry information about the packages or derivations they refer to,
  7499. and these dependencies are automatically added as inputs to the build
  7500. processes that use them.
  7501. @end itemize
  7502. @cindex lowering, of high-level objects in gexps
  7503. This mechanism is not limited to package and derivation
  7504. objects: @dfn{compilers} able to ``lower'' other high-level objects to
  7505. derivations or files in the store can be defined,
  7506. such that these objects can also be inserted
  7507. into gexps. For example, a useful type of high-level objects that can be
  7508. inserted in a gexp is ``file-like objects'', which make it easy to
  7509. add files to the store and to refer to them in
  7510. derivations and such (see @code{local-file} and @code{plain-file}
  7511. below).
  7512. To illustrate the idea, here is an example of a gexp:
  7513. @lisp
  7514. (define build-exp
  7515. #~(begin
  7516. (mkdir #$output)
  7517. (chdir #$output)
  7518. (symlink (string-append #$coreutils "/bin/ls")
  7519. "list-files")))
  7520. @end lisp
  7521. This gexp can be passed to @code{gexp->derivation}; we obtain a
  7522. derivation that builds a directory containing exactly one symlink to
  7523. @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
  7524. @lisp
  7525. (gexp->derivation "the-thing" build-exp)
  7526. @end lisp
  7527. As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
  7528. substituted to the reference to the @var{coreutils} package in the
  7529. actual build code, and @var{coreutils} is automatically made an input to
  7530. the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
  7531. output)}) is replaced by a string containing the directory name of the
  7532. output of the derivation.
  7533. @cindex cross compilation
  7534. In a cross-compilation context, it is useful to distinguish between
  7535. references to the @emph{native} build of a package---that can run on the
  7536. host---versus references to cross builds of a package. To that end, the
  7537. @code{#+} plays the same role as @code{#$}, but is a reference to a
  7538. native package build:
  7539. @lisp
  7540. (gexp->derivation "vi"
  7541. #~(begin
  7542. (mkdir #$output)
  7543. (mkdir (string-append #$output "/bin"))
  7544. (system* (string-append #+coreutils "/bin/ln")
  7545. "-s"
  7546. (string-append #$emacs "/bin/emacs")
  7547. (string-append #$output "/bin/vi")))
  7548. #:target "aarch64-linux-gnu")
  7549. @end lisp
  7550. @noindent
  7551. In the example above, the native build of @var{coreutils} is used, so
  7552. that @command{ln} can actually run on the host; but then the
  7553. cross-compiled build of @var{emacs} is referenced.
  7554. @cindex imported modules, for gexps
  7555. @findex with-imported-modules
  7556. Another gexp feature is @dfn{imported modules}: sometimes you want to be
  7557. able to use certain Guile modules from the ``host environment'' in the
  7558. gexp, so those modules should be imported in the ``build environment''.
  7559. The @code{with-imported-modules} form allows you to express that:
  7560. @lisp
  7561. (let ((build (with-imported-modules '((guix build utils))
  7562. #~(begin
  7563. (use-modules (guix build utils))
  7564. (mkdir-p (string-append #$output "/bin"))))))
  7565. (gexp->derivation "empty-dir"
  7566. #~(begin
  7567. #$build
  7568. (display "success!\n")
  7569. #t)))
  7570. @end lisp
  7571. @noindent
  7572. In this example, the @code{(guix build utils)} module is automatically
  7573. pulled into the isolated build environment of our gexp, such that
  7574. @code{(use-modules (guix build utils))} works as expected.
  7575. @cindex module closure
  7576. @findex source-module-closure
  7577. Usually you want the @emph{closure} of the module to be imported---i.e.,
  7578. the module itself and all the modules it depends on---rather than just
  7579. the module; failing to do that, attempts to use the module will fail
  7580. because of missing dependent modules. The @code{source-module-closure}
  7581. procedure computes the closure of a module by looking at its source file
  7582. headers, which comes in handy in this case:
  7583. @lisp
  7584. (use-modules (guix modules)) ;for 'source-module-closure'
  7585. (with-imported-modules (source-module-closure
  7586. '((guix build utils)
  7587. (gnu build vm)))
  7588. (gexp->derivation "something-with-vms"
  7589. #~(begin
  7590. (use-modules (guix build utils)
  7591. (gnu build vm))
  7592. @dots{})))
  7593. @end lisp
  7594. @cindex extensions, for gexps
  7595. @findex with-extensions
  7596. In the same vein, sometimes you want to import not just pure-Scheme
  7597. modules, but also ``extensions'' such as Guile bindings to C libraries
  7598. or other ``full-blown'' packages. Say you need the @code{guile-json}
  7599. package available on the build side, here's how you would do it:
  7600. @lisp
  7601. (use-modules (gnu packages guile)) ;for 'guile-json'
  7602. (with-extensions (list guile-json)
  7603. (gexp->derivation "something-with-json"
  7604. #~(begin
  7605. (use-modules (json))
  7606. @dots{})))
  7607. @end lisp
  7608. The syntactic form to construct gexps is summarized below.
  7609. @deffn {Scheme Syntax} #~@var{exp}
  7610. @deffnx {Scheme Syntax} (gexp @var{exp})
  7611. Return a G-expression containing @var{exp}. @var{exp} may contain one
  7612. or more of the following forms:
  7613. @table @code
  7614. @item #$@var{obj}
  7615. @itemx (ungexp @var{obj})
  7616. Introduce a reference to @var{obj}. @var{obj} may have one of the
  7617. supported types, for example a package or a
  7618. derivation, in which case the @code{ungexp} form is replaced by its
  7619. output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
  7620. If @var{obj} is a list, it is traversed and references to supported
  7621. objects are substituted similarly.
  7622. If @var{obj} is another gexp, its contents are inserted and its
  7623. dependencies are added to those of the containing gexp.
  7624. If @var{obj} is another kind of object, it is inserted as is.
  7625. @item #$@var{obj}:@var{output}
  7626. @itemx (ungexp @var{obj} @var{output})
  7627. This is like the form above, but referring explicitly to the
  7628. @var{output} of @var{obj}---this is useful when @var{obj} produces
  7629. multiple outputs (@pxref{Packages with Multiple Outputs}).
  7630. @item #+@var{obj}
  7631. @itemx #+@var{obj}:output
  7632. @itemx (ungexp-native @var{obj})
  7633. @itemx (ungexp-native @var{obj} @var{output})
  7634. Same as @code{ungexp}, but produces a reference to the @emph{native}
  7635. build of @var{obj} when used in a cross compilation context.
  7636. @item #$output[:@var{output}]
  7637. @itemx (ungexp output [@var{output}])
  7638. Insert a reference to derivation output @var{output}, or to the main
  7639. output when @var{output} is omitted.
  7640. This only makes sense for gexps passed to @code{gexp->derivation}.
  7641. @item #$@@@var{lst}
  7642. @itemx (ungexp-splicing @var{lst})
  7643. Like the above, but splices the contents of @var{lst} inside the
  7644. containing list.
  7645. @item #+@@@var{lst}
  7646. @itemx (ungexp-native-splicing @var{lst})
  7647. Like the above, but refers to native builds of the objects listed in
  7648. @var{lst}.
  7649. @end table
  7650. G-expressions created by @code{gexp} or @code{#~} are run-time objects
  7651. of the @code{gexp?} type (see below).
  7652. @end deffn
  7653. @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
  7654. Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
  7655. in their execution environment.
  7656. Each item in @var{modules} can be the name of a module, such as
  7657. @code{(guix build utils)}, or it can be a module name, followed by an
  7658. arrow, followed by a file-like object:
  7659. @lisp
  7660. `((guix build utils)
  7661. (guix gcrypt)
  7662. ((guix config) => ,(scheme-file "config.scm"
  7663. #~(define-module @dots{}))))
  7664. @end lisp
  7665. @noindent
  7666. In the example above, the first two modules are taken from the search
  7667. path, and the last one is created from the given file-like object.
  7668. This form has @emph{lexical} scope: it has an effect on the gexps
  7669. directly defined in @var{body}@dots{}, but not on those defined, say, in
  7670. procedures called from @var{body}@dots{}.
  7671. @end deffn
  7672. @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
  7673. Mark the gexps defined in @var{body}@dots{} as requiring
  7674. @var{extensions} in their build and execution environment.
  7675. @var{extensions} is typically a list of package objects such as those
  7676. defined in the @code{(gnu packages guile)} module.
  7677. Concretely, the packages listed in @var{extensions} are added to the
  7678. load path while compiling imported modules in @var{body}@dots{}; they
  7679. are also added to the load path of the gexp returned by
  7680. @var{body}@dots{}.
  7681. @end deffn
  7682. @deffn {Scheme Procedure} gexp? @var{obj}
  7683. Return @code{#t} if @var{obj} is a G-expression.
  7684. @end deffn
  7685. G-expressions are meant to be written to disk, either as code building
  7686. some derivation, or as plain files in the store. The monadic procedures
  7687. below allow you to do that (@pxref{The Store Monad}, for more
  7688. information about monads).
  7689. @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
  7690. [#:system (%current-system)] [#:target #f] [#:graft? #t] @
  7691. [#:hash #f] [#:hash-algo #f] @
  7692. [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
  7693. [#:module-path @code{%load-path}] @
  7694. [#:effective-version "2.2"] @
  7695. [#:references-graphs #f] [#:allowed-references #f] @
  7696. [#:disallowed-references #f] @
  7697. [#:leaked-env-vars #f] @
  7698. [#:script-name (string-append @var{name} "-builder")] @
  7699. [#:deprecation-warnings #f] @
  7700. [#:local-build? #f] [#:substitutable? #t] @
  7701. [#:properties '()] [#:guile-for-build #f]
  7702. Return a derivation @var{name} that runs @var{exp} (a gexp) with
  7703. @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
  7704. stored in a file called @var{script-name}. When @var{target} is true,
  7705. it is used as the cross-compilation target triplet for packages referred
  7706. to by @var{exp}.
  7707. @var{modules} is deprecated in favor of @code{with-imported-modules}.
  7708. Its meaning is to
  7709. make @var{modules} available in the evaluation context of @var{exp};
  7710. @var{modules} is a list of names of Guile modules searched in
  7711. @var{module-path} to be copied in the store, compiled, and made available in
  7712. the load path during the execution of @var{exp}---e.g., @code{((guix
  7713. build utils) (guix build gnu-build-system))}.
  7714. @var{effective-version} determines the string to use when adding extensions of
  7715. @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
  7716. @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
  7717. applicable.
  7718. When @var{references-graphs} is true, it must be a list of tuples of one of the
  7719. following forms:
  7720. @example
  7721. (@var{file-name} @var{package})
  7722. (@var{file-name} @var{package} @var{output})
  7723. (@var{file-name} @var{derivation})
  7724. (@var{file-name} @var{derivation} @var{output})
  7725. (@var{file-name} @var{store-item})
  7726. @end example
  7727. The right-hand-side of each element of @var{references-graphs} is automatically made
  7728. an input of the build process of @var{exp}. In the build environment, each
  7729. @var{file-name} contains the reference graph of the corresponding item, in a simple
  7730. text format.
  7731. @var{allowed-references} must be either @code{#f} or a list of output names and packages.
  7732. In the latter case, the list denotes store items that the result is allowed to
  7733. refer to. Any reference to another store item will lead to a build error.
  7734. Similarly for @var{disallowed-references}, which can list items that must not be
  7735. referenced by the outputs.
  7736. @var{deprecation-warnings} determines whether to show deprecation warnings while
  7737. compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
  7738. The other arguments are as for @code{derivation} (@pxref{Derivations}).
  7739. @end deffn
  7740. @cindex file-like objects
  7741. The @code{local-file}, @code{plain-file}, @code{computed-file},
  7742. @code{program-file}, and @code{scheme-file} procedures below return
  7743. @dfn{file-like objects}. That is, when unquoted in a G-expression,
  7744. these objects lead to a file in the store. Consider this G-expression:
  7745. @lisp
  7746. #~(system* #$(file-append glibc "/sbin/nscd") "-f"
  7747. #$(local-file "/tmp/my-nscd.conf"))
  7748. @end lisp
  7749. The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
  7750. to the store. Once expanded, for instance @i{via}
  7751. @code{gexp->derivation}, the G-expression refers to that copy under
  7752. @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
  7753. does not have any effect on what the G-expression does.
  7754. @code{plain-file} can be used similarly; it differs in that the file
  7755. content is directly passed as a string.
  7756. @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
  7757. [#:recursive? #f] [#:select? (const #t)]
  7758. Return an object representing local file @var{file} to add to the store;
  7759. this object can be used in a gexp. If @var{file} is a literal string
  7760. denoting a relative file name, it is looked up relative to the source
  7761. file where it appears; if @var{file} is not a literal string, it is
  7762. looked up relative to the current working directory at run time.
  7763. @var{file} will be added to the store under @var{name}--by default the
  7764. base name of @var{file}.
  7765. When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
  7766. designates a flat file and @var{recursive?} is true, its contents are added, and its
  7767. permission bits are kept.
  7768. When @var{recursive?} is true, call @code{(@var{select?} @var{file}
  7769. @var{stat})} for each directory entry, where @var{file} is the entry's
  7770. absolute file name and @var{stat} is the result of @code{lstat}; exclude
  7771. entries for which @var{select?} does not return true.
  7772. This is the declarative counterpart of the @code{interned-file} monadic
  7773. procedure (@pxref{The Store Monad, @code{interned-file}}).
  7774. @end deffn
  7775. @deffn {Scheme Procedure} plain-file @var{name} @var{content}
  7776. Return an object representing a text file called @var{name} with the given
  7777. @var{content} (a string or a bytevector) to be added to the store.
  7778. This is the declarative counterpart of @code{text-file}.
  7779. @end deffn
  7780. @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
  7781. [#:local-build? #t]
  7782. [#:options '()]
  7783. Return an object representing the store item @var{name}, a file or
  7784. directory computed by @var{gexp}. When @var{local-build?} is true (the
  7785. default), the derivation is built locally. @var{options} is a list of
  7786. additional arguments to pass to @code{gexp->derivation}.
  7787. This is the declarative counterpart of @code{gexp->derivation}.
  7788. @end deffn
  7789. @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
  7790. [#:guile (default-guile)] [#:module-path %load-path] @
  7791. [#:system (%current-system)] [#:target #f]
  7792. Return an executable script @var{name} that runs @var{exp} using
  7793. @var{guile}, with @var{exp}'s imported modules in its search path.
  7794. Look up @var{exp}'s modules in @var{module-path}.
  7795. The example below builds a script that simply invokes the @command{ls}
  7796. command:
  7797. @lisp
  7798. (use-modules (guix gexp) (gnu packages base))
  7799. (gexp->script "list-files"
  7800. #~(execl #$(file-append coreutils "/bin/ls")
  7801. "ls"))
  7802. @end lisp
  7803. When ``running'' it through the store (@pxref{The Store Monad,
  7804. @code{run-with-store}}), we obtain a derivation that produces an
  7805. executable file @file{/gnu/store/@dots{}-list-files} along these lines:
  7806. @example
  7807. #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
  7808. !#
  7809. (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
  7810. @end example
  7811. @end deffn
  7812. @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
  7813. [#:guile #f] [#:module-path %load-path]
  7814. Return an object representing the executable store item @var{name} that
  7815. runs @var{gexp}. @var{guile} is the Guile package used to execute that
  7816. script. Imported modules of @var{gexp} are looked up in @var{module-path}.
  7817. This is the declarative counterpart of @code{gexp->script}.
  7818. @end deffn
  7819. @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
  7820. [#:set-load-path? #t] [#:module-path %load-path] @
  7821. [#:splice? #f] @
  7822. [#:guile (default-guile)]
  7823. Return a derivation that builds a file @var{name} containing @var{exp}.
  7824. When @var{splice?} is true, @var{exp} is considered to be a list of
  7825. expressions that will be spliced in the resulting file.
  7826. When @var{set-load-path?} is true, emit code in the resulting file to
  7827. set @code{%load-path} and @code{%load-compiled-path} to honor
  7828. @var{exp}'s imported modules. Look up @var{exp}'s modules in
  7829. @var{module-path}.
  7830. The resulting file holds references to all the dependencies of @var{exp}
  7831. or a subset thereof.
  7832. @end deffn
  7833. @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
  7834. [#:splice? #f] [#:set-load-path? #t]
  7835. Return an object representing the Scheme file @var{name} that contains
  7836. @var{exp}.
  7837. This is the declarative counterpart of @code{gexp->file}.
  7838. @end deffn
  7839. @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
  7840. Return as a monadic value a derivation that builds a text file
  7841. containing all of @var{text}. @var{text} may list, in addition to
  7842. strings, objects of any type that can be used in a gexp: packages,
  7843. derivations, local file objects, etc. The resulting store file holds
  7844. references to all these.
  7845. This variant should be preferred over @code{text-file} anytime the file
  7846. to create will reference items from the store. This is typically the
  7847. case when building a configuration file that embeds store file names,
  7848. like this:
  7849. @lisp
  7850. (define (profile.sh)
  7851. ;; Return the name of a shell script in the store that
  7852. ;; initializes the 'PATH' environment variable.
  7853. (text-file* "profile.sh"
  7854. "export PATH=" coreutils "/bin:"
  7855. grep "/bin:" sed "/bin\n"))
  7856. @end lisp
  7857. In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
  7858. will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
  7859. preventing them from being garbage-collected during its lifetime.
  7860. @end deffn
  7861. @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
  7862. Return an object representing store file @var{name} containing
  7863. @var{text}. @var{text} is a sequence of strings and file-like objects,
  7864. as in:
  7865. @lisp
  7866. (mixed-text-file "profile"
  7867. "export PATH=" coreutils "/bin:" grep "/bin")
  7868. @end lisp
  7869. This is the declarative counterpart of @code{text-file*}.
  7870. @end deffn
  7871. @deffn {Scheme Procedure} file-union @var{name} @var{files}
  7872. Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
  7873. Each item in @var{files} must be a two-element list where the first element is the
  7874. file name to use in the new directory, and the second element is a gexp
  7875. denoting the target file. Here's an example:
  7876. @lisp
  7877. (file-union "etc"
  7878. `(("hosts" ,(plain-file "hosts"
  7879. "127.0.0.1 localhost"))
  7880. ("bashrc" ,(plain-file "bashrc"
  7881. "alias ls='ls --color=auto'"))))
  7882. @end lisp
  7883. This yields an @code{etc} directory containing these two files.
  7884. @end deffn
  7885. @deffn {Scheme Procedure} directory-union @var{name} @var{things}
  7886. Return a directory that is the union of @var{things}, where @var{things} is a list of
  7887. file-like objects denoting directories. For example:
  7888. @lisp
  7889. (directory-union "guile+emacs" (list guile emacs))
  7890. @end lisp
  7891. yields a directory that is the union of the @code{guile} and @code{emacs} packages.
  7892. @end deffn
  7893. @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
  7894. Return a file-like object that expands to the concatenation of @var{obj}
  7895. and @var{suffix}, where @var{obj} is a lowerable object and each
  7896. @var{suffix} is a string.
  7897. As an example, consider this gexp:
  7898. @lisp
  7899. (gexp->script "run-uname"
  7900. #~(system* #$(file-append coreutils
  7901. "/bin/uname")))
  7902. @end lisp
  7903. The same effect could be achieved with:
  7904. @lisp
  7905. (gexp->script "run-uname"
  7906. #~(system* (string-append #$coreutils
  7907. "/bin/uname")))
  7908. @end lisp
  7909. There is one difference though: in the @code{file-append} case, the
  7910. resulting script contains the absolute file name as a string, whereas in
  7911. the second case, the resulting script contains a @code{(string-append
  7912. @dots{})} expression to construct the file name @emph{at run time}.
  7913. @end deffn
  7914. @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
  7915. @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
  7916. Bind @var{system} to the currently targeted system---e.g.,
  7917. @code{"x86_64-linux"}---within @var{body}.
  7918. In the second case, additionally bind @var{target} to the current
  7919. cross-compilation target---a GNU triplet such as
  7920. @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
  7921. cross-compiling.
  7922. @code{let-system} is useful in the occasional case where the object
  7923. spliced into the gexp depends on the target system, as in this example:
  7924. @lisp
  7925. #~(system*
  7926. #+(let-system system
  7927. (cond ((string-prefix? "armhf-" system)
  7928. (file-append qemu "/bin/qemu-system-arm"))
  7929. ((string-prefix? "x86_64-" system)
  7930. (file-append qemu "/bin/qemu-system-x86_64"))
  7931. (else
  7932. (error "dunno!"))))
  7933. "-net" "user" #$image)
  7934. @end lisp
  7935. @end deffn
  7936. @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
  7937. This macro is similar to the @code{parameterize} form for
  7938. dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
  7939. Guile Reference Manual}). The key difference is that it takes effect
  7940. when the file-like object returned by @var{exp} is lowered to a
  7941. derivation or store item.
  7942. A typical use of @code{with-parameters} is to force the system in effect
  7943. for a given object:
  7944. @lisp
  7945. (with-parameters ((%current-system "i686-linux"))
  7946. coreutils)
  7947. @end lisp
  7948. The example above returns an object that corresponds to the i686 build
  7949. of Coreutils, regardless of the current value of @code{%current-system}.
  7950. @end deffn
  7951. Of course, in addition to gexps embedded in ``host'' code, there are
  7952. also modules containing build tools. To make it clear that they are
  7953. meant to be used in the build stratum, these modules are kept in the
  7954. @code{(guix build @dots{})} name space.
  7955. @cindex lowering, of high-level objects in gexps
  7956. Internally, high-level objects are @dfn{lowered}, using their compiler,
  7957. to either derivations or store items. For instance, lowering a package
  7958. yields a derivation, and lowering a @code{plain-file} yields a store
  7959. item. This is achieved using the @code{lower-object} monadic procedure.
  7960. @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
  7961. [#:target #f]
  7962. Return as a value in @code{%store-monad} the derivation or store item
  7963. corresponding to @var{obj} for @var{system}, cross-compiling for
  7964. @var{target} if @var{target} is true. @var{obj} must be an object that
  7965. has an associated gexp compiler, such as a @code{<package>}.
  7966. @end deffn
  7967. @node Invoking guix repl
  7968. @section Invoking @command{guix repl}
  7969. @cindex REPL, read-eval-print loop, script
  7970. The @command{guix repl} command makes it easier to program Guix in Guile
  7971. by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
  7972. programming (@pxref{Using Guile Interactively,,, guile,
  7973. GNU Guile Reference Manual}), or by running Guile scripts
  7974. (@pxref{Running Guile Scripts,,, guile,
  7975. GNU Guile Reference Manual}).
  7976. Compared to just launching the @command{guile}
  7977. command, @command{guix repl} guarantees that all the Guix modules and all its
  7978. dependencies are available in the search path.
  7979. The general syntax is:
  7980. @example
  7981. guix repl @var{options} [@var{file} @var{args}]
  7982. @end example
  7983. When a @var{file} argument is provided, @var{file} is
  7984. executed as a Guile scripts:
  7985. @example
  7986. guix repl my-script.scm
  7987. @end example
  7988. To pass arguments to the script, use @code{--} to prevent them from
  7989. being interpreted as arguments to @command{guix repl} itself:
  7990. @example
  7991. guix repl -- my-script.scm --input=foo.txt
  7992. @end example
  7993. To make a script executable directly from the shell, using the guix
  7994. executable that is on the user's search path, add the following two
  7995. lines at the top of the script:
  7996. @example
  7997. @code{#!/usr/bin/env -S guix repl --}
  7998. @code{!#}
  7999. @end example
  8000. Without a file name argument, a Guile REPL is started:
  8001. @example
  8002. $ guix repl
  8003. scheme@@(guile-user)> ,use (gnu packages base)
  8004. scheme@@(guile-user)> coreutils
  8005. $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
  8006. @end example
  8007. @cindex inferiors
  8008. In addition, @command{guix repl} implements a simple machine-readable REPL
  8009. protocol for use by @code{(guix inferior)}, a facility to interact with
  8010. @dfn{inferiors}, separate processes running a potentially different revision
  8011. of Guix.
  8012. The available options are as follows:
  8013. @table @code
  8014. @item --type=@var{type}
  8015. @itemx -t @var{type}
  8016. Start a REPL of the given @var{TYPE}, which can be one of the following:
  8017. @table @code
  8018. @item guile
  8019. This is default, and it spawns a standard full-featured Guile REPL.
  8020. @item machine
  8021. Spawn a REPL that uses the machine-readable protocol. This is the protocol
  8022. that the @code{(guix inferior)} module speaks.
  8023. @end table
  8024. @item --listen=@var{endpoint}
  8025. By default, @command{guix repl} reads from standard input and writes to
  8026. standard output. When this option is passed, it will instead listen for
  8027. connections on @var{endpoint}. Here are examples of valid options:
  8028. @table @code
  8029. @item --listen=tcp:37146
  8030. Accept connections on localhost on port 37146.
  8031. @item --listen=unix:/tmp/socket
  8032. Accept connections on the Unix-domain socket @file{/tmp/socket}.
  8033. @end table
  8034. @item --load-path=@var{directory}
  8035. @itemx -L @var{directory}
  8036. Add @var{directory} to the front of the package module search path
  8037. (@pxref{Package Modules}).
  8038. This allows users to define their own packages and make them visible to
  8039. the script or REPL.
  8040. @item -q
  8041. Inhibit loading of the @file{~/.guile} file. By default, that
  8042. configuration file is loaded when spawning a @code{guile} REPL.
  8043. @end table
  8044. @c *********************************************************************
  8045. @node Utilities
  8046. @chapter Utilities
  8047. This section describes Guix command-line utilities. Some of them are
  8048. primarily targeted at developers and users who write new package
  8049. definitions, while others are more generally useful. They complement
  8050. the Scheme programming interface of Guix in a convenient way.
  8051. @menu
  8052. * Invoking guix build:: Building packages from the command line.
  8053. * Invoking guix edit:: Editing package definitions.
  8054. * Invoking guix download:: Downloading a file and printing its hash.
  8055. * Invoking guix hash:: Computing the cryptographic hash of a file.
  8056. * Invoking guix import:: Importing package definitions.
  8057. * Invoking guix refresh:: Updating package definitions.
  8058. * Invoking guix lint:: Finding errors in package definitions.
  8059. * Invoking guix size:: Profiling disk usage.
  8060. * Invoking guix graph:: Visualizing the graph of packages.
  8061. * Invoking guix publish:: Sharing substitutes.
  8062. * Invoking guix challenge:: Challenging substitute servers.
  8063. * Invoking guix copy:: Copying to and from a remote store.
  8064. * Invoking guix container:: Process isolation.
  8065. * Invoking guix weather:: Assessing substitute availability.
  8066. * Invoking guix processes:: Listing client processes.
  8067. @end menu
  8068. @node Invoking guix build
  8069. @section Invoking @command{guix build}
  8070. @cindex package building
  8071. @cindex @command{guix build}
  8072. The @command{guix build} command builds packages or derivations and
  8073. their dependencies, and prints the resulting store paths. Note that it
  8074. does not modify the user's profile---this is the job of the
  8075. @command{guix package} command (@pxref{Invoking guix package}). Thus,
  8076. it is mainly useful for distribution developers.
  8077. The general syntax is:
  8078. @example
  8079. guix build @var{options} @var{package-or-derivation}@dots{}
  8080. @end example
  8081. As an example, the following command builds the latest versions of Emacs
  8082. and of Guile, displays their build logs, and finally displays the
  8083. resulting directories:
  8084. @example
  8085. guix build emacs guile
  8086. @end example
  8087. Similarly, the following command builds all the available packages:
  8088. @example
  8089. guix build --quiet --keep-going \
  8090. `guix package -A | cut -f1,2 --output-delimiter=@@`
  8091. @end example
  8092. @var{package-or-derivation} may be either the name of a package found in
  8093. the software distribution such as @code{coreutils} or
  8094. @code{coreutils@@8.20}, or a derivation such as
  8095. @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
  8096. package with the corresponding name (and optionally version) is searched
  8097. for among the GNU distribution modules (@pxref{Package Modules}).
  8098. Alternatively, the @option{--expression} option may be used to specify a
  8099. Scheme expression that evaluates to a package; this is useful when
  8100. disambiguating among several same-named packages or package variants is
  8101. needed.
  8102. There may be zero or more @var{options}. The available options are
  8103. described in the subsections below.
  8104. @menu
  8105. * Common Build Options:: Build options for most commands.
  8106. * Package Transformation Options:: Creating variants of packages.
  8107. * Additional Build Options:: Options specific to 'guix build'.
  8108. * Debugging Build Failures:: Real life packaging experience.
  8109. @end menu
  8110. @node Common Build Options
  8111. @subsection Common Build Options
  8112. A number of options that control the build process are common to
  8113. @command{guix build} and other commands that can spawn builds, such as
  8114. @command{guix package} or @command{guix archive}. These are the
  8115. following:
  8116. @table @code
  8117. @item --load-path=@var{directory}
  8118. @itemx -L @var{directory}
  8119. Add @var{directory} to the front of the package module search path
  8120. (@pxref{Package Modules}).
  8121. This allows users to define their own packages and make them visible to
  8122. the command-line tools.
  8123. @item --keep-failed
  8124. @itemx -K
  8125. Keep the build tree of failed builds. Thus, if a build fails, its build
  8126. tree is kept under @file{/tmp}, in a directory whose name is shown at
  8127. the end of the build log. This is useful when debugging build issues.
  8128. @xref{Debugging Build Failures}, for tips and tricks on how to debug
  8129. build issues.
  8130. This option implies @option{--no-offload}, and it has no effect when
  8131. connecting to a remote daemon with a @code{guix://} URI (@pxref{The
  8132. Store, the @env{GUIX_DAEMON_SOCKET} variable}).
  8133. @item --keep-going
  8134. @itemx -k
  8135. Keep going when some of the derivations fail to build; return only once
  8136. all the builds have either completed or failed.
  8137. The default behavior is to stop as soon as one of the specified
  8138. derivations has failed.
  8139. @item --dry-run
  8140. @itemx -n
  8141. Do not build the derivations.
  8142. @anchor{fallback-option}
  8143. @item --fallback
  8144. When substituting a pre-built binary fails, fall back to building
  8145. packages locally (@pxref{Substitution Failure}).
  8146. @item --substitute-urls=@var{urls}
  8147. @anchor{client-substitute-urls}
  8148. Consider @var{urls} the whitespace-separated list of substitute source
  8149. URLs, overriding the default list of URLs of @command{guix-daemon}
  8150. (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
  8151. This means that substitutes may be downloaded from @var{urls}, provided
  8152. they are signed by a key authorized by the system administrator
  8153. (@pxref{Substitutes}).
  8154. When @var{urls} is the empty string, substitutes are effectively
  8155. disabled.
  8156. @item --no-substitutes
  8157. Do not use substitutes for build products. That is, always build things
  8158. locally instead of allowing downloads of pre-built binaries
  8159. (@pxref{Substitutes}).
  8160. @item --no-grafts
  8161. Do not ``graft'' packages. In practice, this means that package updates
  8162. available as grafts are not applied. @xref{Security Updates}, for more
  8163. information on grafts.
  8164. @item --rounds=@var{n}
  8165. Build each derivation @var{n} times in a row, and raise an error if
  8166. consecutive build results are not bit-for-bit identical.
  8167. This is a useful way to detect non-deterministic builds processes.
  8168. Non-deterministic build processes are a problem because they make it
  8169. practically impossible for users to @emph{verify} whether third-party
  8170. binaries are genuine. @xref{Invoking guix challenge}, for more.
  8171. When used in conjunction with @option{--keep-failed}, the differing
  8172. output is kept in the store, under @file{/gnu/store/@dots{}-check}.
  8173. This makes it easy to look for differences between the two results.
  8174. @item --no-offload
  8175. Do not use offload builds to other machines (@pxref{Daemon Offload
  8176. Setup}). That is, always build things locally instead of offloading
  8177. builds to remote machines.
  8178. @item --max-silent-time=@var{seconds}
  8179. When the build or substitution process remains silent for more than
  8180. @var{seconds}, terminate it and report a build failure.
  8181. By default, the daemon's setting is honored (@pxref{Invoking
  8182. guix-daemon, @option{--max-silent-time}}).
  8183. @item --timeout=@var{seconds}
  8184. Likewise, when the build or substitution process lasts for more than
  8185. @var{seconds}, terminate it and report a build failure.
  8186. By default, the daemon's setting is honored (@pxref{Invoking
  8187. guix-daemon, @option{--timeout}}).
  8188. @c Note: This option is actually not part of %standard-build-options but
  8189. @c most programs honor it.
  8190. @cindex verbosity, of the command-line tools
  8191. @cindex build logs, verbosity
  8192. @item -v @var{level}
  8193. @itemx --verbosity=@var{level}
  8194. Use the given verbosity @var{level}, an integer. Choosing 0 means that no
  8195. output is produced, 1 is for quiet output, and 2 shows all the build log
  8196. output on standard error.
  8197. @item --cores=@var{n}
  8198. @itemx -c @var{n}
  8199. Allow the use of up to @var{n} CPU cores for the build. The special
  8200. value @code{0} means to use as many CPU cores as available.
  8201. @item --max-jobs=@var{n}
  8202. @itemx -M @var{n}
  8203. Allow at most @var{n} build jobs in parallel. @xref{Invoking
  8204. guix-daemon, @option{--max-jobs}}, for details about this option and the
  8205. equivalent @command{guix-daemon} option.
  8206. @item --debug=@var{level}
  8207. Produce debugging output coming from the build daemon. @var{level} must be an
  8208. integer between 0 and 5; higher means more verbose output. Setting a level of
  8209. 4 or more may be helpful when debugging setup issues with the build daemon.
  8210. @end table
  8211. Behind the scenes, @command{guix build} is essentially an interface to
  8212. the @code{package-derivation} procedure of the @code{(guix packages)}
  8213. module, and to the @code{build-derivations} procedure of the @code{(guix
  8214. derivations)} module.
  8215. In addition to options explicitly passed on the command line,
  8216. @command{guix build} and other @command{guix} commands that support
  8217. building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
  8218. @defvr {Environment Variable} GUIX_BUILD_OPTIONS
  8219. Users can define this variable to a list of command line options that
  8220. will automatically be used by @command{guix build} and other
  8221. @command{guix} commands that can perform builds, as in the example
  8222. below:
  8223. @example
  8224. $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
  8225. @end example
  8226. These options are parsed independently, and the result is appended to
  8227. the parsed command-line options.
  8228. @end defvr
  8229. @node Package Transformation Options
  8230. @subsection Package Transformation Options
  8231. @cindex package variants
  8232. Another set of command-line options supported by @command{guix build}
  8233. and also @command{guix package} are @dfn{package transformation
  8234. options}. These are options that make it possible to define @dfn{package
  8235. variants}---for instance, packages built from different source code.
  8236. This is a convenient way to create customized packages on the fly
  8237. without having to type in the definitions of package variants
  8238. (@pxref{Defining Packages}).
  8239. Package transformation options are preserved across upgrades:
  8240. @command{guix upgrade} attempts to apply transformation options
  8241. initially used when creating the profile to the upgraded packages.
  8242. The available options are listed below. Most commands support them and
  8243. also support a @option{--help-transform} option that lists all the
  8244. available options and a synopsis (these options are not shown in the
  8245. @option{--help} output for brevity).
  8246. @table @code
  8247. @item --with-source=@var{source}
  8248. @itemx --with-source=@var{package}=@var{source}
  8249. @itemx --with-source=@var{package}@@@var{version}=@var{source}
  8250. Use @var{source} as the source of @var{package}, and @var{version} as
  8251. its version number.
  8252. @var{source} must be a file name or a URL, as for @command{guix
  8253. download} (@pxref{Invoking guix download}).
  8254. When @var{package} is omitted,
  8255. it is taken to be the package name specified on the
  8256. command line that matches the base of @var{source}---e.g.,
  8257. if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
  8258. package is @code{guile}.
  8259. Likewise, when @var{version} is omitted, the version string is inferred from
  8260. @var{source}; in the previous example, it is @code{2.0.10}.
  8261. This option allows users to try out versions of packages other than the
  8262. one provided by the distribution. The example below downloads
  8263. @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
  8264. the @code{ed} package:
  8265. @example
  8266. guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
  8267. @end example
  8268. As a developer, @option{--with-source} makes it easy to test release
  8269. candidates:
  8270. @example
  8271. guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
  8272. @end example
  8273. @dots{} or to build from a checkout in a pristine environment:
  8274. @example
  8275. $ git clone git://git.sv.gnu.org/guix.git
  8276. $ guix build guix --with-source=guix@@1.0=./guix
  8277. @end example
  8278. @item --with-input=@var{package}=@var{replacement}
  8279. Replace dependency on @var{package} by a dependency on
  8280. @var{replacement}. @var{package} must be a package name, and
  8281. @var{replacement} must be a package specification such as @code{guile}
  8282. or @code{guile@@1.8}.
  8283. For instance, the following command builds Guix, but replaces its
  8284. dependency on the current stable version of Guile with a dependency on
  8285. the legacy version of Guile, @code{guile@@2.0}:
  8286. @example
  8287. guix build --with-input=guile=guile@@2.0 guix
  8288. @end example
  8289. This is a recursive, deep replacement. So in this example, both
  8290. @code{guix} and its dependency @code{guile-json} (which also depends on
  8291. @code{guile}) get rebuilt against @code{guile@@2.0}.
  8292. This is implemented using the @code{package-input-rewriting} Scheme
  8293. procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
  8294. @item --with-graft=@var{package}=@var{replacement}
  8295. This is similar to @option{--with-input} but with an important difference:
  8296. instead of rebuilding the whole dependency chain, @var{replacement} is
  8297. built and then @dfn{grafted} onto the binaries that were initially
  8298. referring to @var{package}. @xref{Security Updates}, for more
  8299. information on grafts.
  8300. For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
  8301. and all its dependencies, replacing references to the version of GnuTLS
  8302. they currently refer to:
  8303. @example
  8304. guix build --with-graft=gnutls=gnutls@@3.5.4 wget
  8305. @end example
  8306. This has the advantage of being much faster than rebuilding everything.
  8307. But there is a caveat: it works if and only if @var{package} and
  8308. @var{replacement} are strictly compatible---for example, if they provide
  8309. a library, the application binary interface (ABI) of those libraries
  8310. must be compatible. If @var{replacement} is somehow incompatible with
  8311. @var{package}, then the resulting package may be unusable. Use with
  8312. care!
  8313. @cindex debugging info, rebuilding
  8314. @item --with-debug-info=@var{package}
  8315. Build @var{package} in a way that preserves its debugging info and graft
  8316. it onto packages that depend on it. This is useful if @var{package}
  8317. does not already provide debugging info as a @code{debug} output
  8318. (@pxref{Installing Debugging Files}).
  8319. For example, suppose you're experiencing a crash in Inkscape and would
  8320. like to see what's up in GLib, a library deep down in Inkscape's
  8321. dependency graph. GLib lacks a @code{debug} output, so debugging is
  8322. tough. Fortunately, you rebuild GLib with debugging info and tack it on
  8323. Inkscape:
  8324. @example
  8325. guix install inkscape --with-debug-info=glib
  8326. @end example
  8327. Only GLib needs to be recompiled so this takes a reasonable amount of
  8328. time. @xref{Installing Debugging Files}, for more info.
  8329. @quotation Note
  8330. Under the hood, this option works by passing the @samp{#:strip-binaries?
  8331. #f} to the build system of the package of interest (@pxref{Build
  8332. Systems}). Most build systems support that option but some do not. In
  8333. that case, an error is raised.
  8334. Likewise, if a C/C++ package is built without @code{-g} (which is rarely
  8335. the case), debugging info will remain unavailable even when
  8336. @code{#:strip-binaries?} is false.
  8337. @end quotation
  8338. @cindex tool chain, changing the build tool chain of a package
  8339. @item --with-c-toolchain=@var{package}=@var{toolchain}
  8340. This option changes the compilation of @var{package} and everything that
  8341. depends on it so that they get built with @var{toolchain} instead of the
  8342. default GNU tool chain for C/C++.
  8343. Consider this example:
  8344. @example
  8345. guix build octave-cli \
  8346. --with-c-toolchain=fftw=gcc-toolchain@@10 \
  8347. --with-c-toolchain=fftwf=gcc-toolchain@@10
  8348. @end example
  8349. The command above builds a variant of the @code{fftw} and @code{fftwf}
  8350. packages using version 10 of @code{gcc-toolchain} instead of the default
  8351. tool chain, and then builds a variant of the GNU@tie{}Octave
  8352. command-line interface using them. GNU@tie{}Octave itself is also built
  8353. with @code{gcc-toolchain@@10}.
  8354. This other example builds the Hardware Locality (@code{hwloc}) library
  8355. and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
  8356. compiler:
  8357. @example
  8358. guix build --with-c-toolchain=hwloc=clang-toolchain \
  8359. intel-mpi-benchmarks
  8360. @end example
  8361. @quotation Note
  8362. There can be application binary interface (ABI) incompatibilities among
  8363. tool chains. This is particularly true of the C++ standard library and
  8364. run-time support libraries such as that of OpenMP@. By rebuilding all
  8365. dependents with the same tool chain, @option{--with-c-toolchain} minimizes
  8366. the risks of incompatibility but cannot entirely eliminate them. Choose
  8367. @var{package} wisely.
  8368. @end quotation
  8369. @item --with-git-url=@var{package}=@var{url}
  8370. @cindex Git, using the latest commit
  8371. @cindex latest commit, building
  8372. Build @var{package} from the latest commit of the @code{master} branch of the
  8373. Git repository at @var{url}. Git sub-modules of the repository are fetched,
  8374. recursively.
  8375. For example, the following command builds the NumPy Python library against the
  8376. latest commit of the master branch of Python itself:
  8377. @example
  8378. guix build python-numpy \
  8379. --with-git-url=python=https://github.com/python/cpython
  8380. @end example
  8381. This option can also be combined with @option{--with-branch} or
  8382. @option{--with-commit} (see below).
  8383. @cindex continuous integration
  8384. Obviously, since it uses the latest commit of the given branch, the result of
  8385. such a command varies over time. Nevertheless it is a convenient way to
  8386. rebuild entire software stacks against the latest commit of one or more
  8387. packages. This is particularly useful in the context of continuous
  8388. integration (CI).
  8389. Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
  8390. consecutive accesses to the same repository. You may want to clean it up once
  8391. in a while to save disk space.
  8392. @item --with-branch=@var{package}=@var{branch}
  8393. Build @var{package} from the latest commit of @var{branch}. If the
  8394. @code{source} field of @var{package} is an origin with the @code{git-fetch}
  8395. method (@pxref{origin Reference}) or a @code{git-checkout} object, the
  8396. repository URL is taken from that @code{source}. Otherwise you have to use
  8397. @option{--with-git-url} to specify the URL of the Git repository.
  8398. For instance, the following command builds @code{guile-sqlite3} from the
  8399. latest commit of its @code{master} branch, and then builds @code{guix} (which
  8400. depends on it) and @code{cuirass} (which depends on @code{guix}) against this
  8401. specific @code{guile-sqlite3} build:
  8402. @example
  8403. guix build --with-branch=guile-sqlite3=master cuirass
  8404. @end example
  8405. @item --with-commit=@var{package}=@var{commit}
  8406. This is similar to @option{--with-branch}, except that it builds from
  8407. @var{commit} rather than the tip of a branch. @var{commit} must be a valid
  8408. Git commit SHA1 identifier or a tag.
  8409. @item --with-patch=@var{package}=@var{file}
  8410. Add @var{file} to the list of patches applied to @var{package}, where
  8411. @var{package} is a spec such as @code{python@@3.8} or @code{glibc}.
  8412. @var{file} must contain a patch; it is applied with the flags specified
  8413. in the @code{origin} of @var{package} (@pxref{origin Reference}), which
  8414. by default includes @code{-p1} (@pxref{patch Directories,,, diffutils,
  8415. Comparing and Merging Files}).
  8416. As an example, the command below rebuilds Coreutils with the GNU C
  8417. Library (glibc) patched with the given patch:
  8418. @example
  8419. guix build coreutils --with-patch=glibc=./glibc-frob.patch
  8420. @end example
  8421. In this example, glibc itself as well as everything that leads to
  8422. Coreutils in the dependency graph is rebuilt.
  8423. @cindex upstream, latest version
  8424. @item --with-latest=@var{package}
  8425. So you like living on the bleeding edge? This option is for you! It
  8426. replaces occurrences of @var{package} in the dependency graph with its
  8427. latest upstream version, as reported by @command{guix refresh}
  8428. (@pxref{Invoking guix refresh}).
  8429. It does so by determining the latest upstream release of @var{package}
  8430. (if possible), downloading it, and authenticating it @emph{if} it comes
  8431. with an OpenPGP signature.
  8432. As an example, the command below builds Guix against the latest version
  8433. of Guile-JSON:
  8434. @example
  8435. guix build guix --with-latest=guile-json
  8436. @end example
  8437. There are limitations. First, in cases where the tool cannot or does
  8438. not know how to authenticate source code, you are at risk of running
  8439. malicious code; a warning is emitted in this case. Second, this option
  8440. simply changes the source used in the existing package definitions,
  8441. which is not always sufficient: there might be additional dependencies
  8442. that need to be added, patches to apply, and more generally the quality
  8443. assurance work that Guix developers normally do will be missing.
  8444. You've been warned! In all the other cases, it's a snappy way to stay
  8445. on top. We encourage you to submit patches updating the actual package
  8446. definitions once you have successfully tested an upgrade
  8447. (@pxref{Contributing}).
  8448. @cindex test suite, skipping
  8449. @item --without-tests=@var{package}
  8450. Build @var{package} without running its tests. This can be useful in
  8451. situations where you want to skip the lengthy test suite of a
  8452. intermediate package, or if a package's test suite fails in a
  8453. non-deterministic fashion. It should be used with care because running
  8454. the test suite is a good way to ensure a package is working as intended.
  8455. Turning off tests leads to a different store item. Consequently, when
  8456. using this option, anything that depends on @var{package} must be
  8457. rebuilt, as in this example:
  8458. @example
  8459. guix install --without-tests=python python-notebook
  8460. @end example
  8461. The command above installs @code{python-notebook} on top of
  8462. @code{python} built without running its test suite. To do so, it also
  8463. rebuilds everything that depends on @code{python}, including
  8464. @code{python-notebook} itself.
  8465. Internally, @option{--without-tests} relies on changing the
  8466. @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
  8467. Systems}). Note that some packages use a customized @code{check} phase
  8468. that does not respect a @code{#:tests? #f} setting. Therefore,
  8469. @option{--without-tests} has no effect on these packages.
  8470. @end table
  8471. Wondering how to achieve the same effect using Scheme code, for example
  8472. in your manifest, or how to write your own package transformation?
  8473. @xref{Defining Package Variants}, for an overview of the programming
  8474. interfaces available.
  8475. @node Additional Build Options
  8476. @subsection Additional Build Options
  8477. The command-line options presented below are specific to @command{guix
  8478. build}.
  8479. @table @code
  8480. @item --quiet
  8481. @itemx -q
  8482. Build quietly, without displaying the build log; this is equivalent to
  8483. @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
  8484. (or similar) and can always be retrieved using the @option{--log-file} option.
  8485. @item --file=@var{file}
  8486. @itemx -f @var{file}
  8487. Build the package, derivation, or other file-like object that the code within
  8488. @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
  8489. As an example, @var{file} might contain a package definition like this
  8490. (@pxref{Defining Packages}):
  8491. @lisp
  8492. @include package-hello.scm
  8493. @end lisp
  8494. The @var{file} may also contain a JSON representation of one or more
  8495. package definitions. Running @code{guix build -f} on @file{hello.json}
  8496. with the following contents would result in building the packages
  8497. @code{myhello} and @code{greeter}:
  8498. @example
  8499. @verbatiminclude package-hello.json
  8500. @end example
  8501. @item --manifest=@var{manifest}
  8502. @itemx -m @var{manifest}
  8503. Build all packages listed in the given @var{manifest}
  8504. (@pxref{profile-manifest, @option{--manifest}}).
  8505. @item --expression=@var{expr}
  8506. @itemx -e @var{expr}
  8507. Build the package or derivation @var{expr} evaluates to.
  8508. For example, @var{expr} may be @code{(@@ (gnu packages guile)
  8509. guile-1.8)}, which unambiguously designates this specific variant of
  8510. version 1.8 of Guile.
  8511. Alternatively, @var{expr} may be a G-expression, in which case it is used
  8512. as a build program passed to @code{gexp->derivation}
  8513. (@pxref{G-Expressions}).
  8514. Lastly, @var{expr} may refer to a zero-argument monadic procedure
  8515. (@pxref{The Store Monad}). The procedure must return a derivation as a
  8516. monadic value, which is then passed through @code{run-with-store}.
  8517. @item --source
  8518. @itemx -S
  8519. Build the source derivations of the packages, rather than the packages
  8520. themselves.
  8521. For instance, @code{guix build -S gcc} returns something like
  8522. @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
  8523. source tarball.
  8524. The returned source tarball is the result of applying any patches and
  8525. code snippets specified in the package @code{origin} (@pxref{Defining
  8526. Packages}).
  8527. @cindex source, verification
  8528. As with other derivations, the result of building a source derivation
  8529. can be verified using the @option{--check} option (@pxref{build-check}).
  8530. This is useful to validate that a (potentially already built or
  8531. substituted, thus cached) package source matches against its declared
  8532. hash.
  8533. Note that @command{guix build -S} compiles the sources only of the
  8534. specified packages. They do not include the sources of statically
  8535. linked dependencies and by themselves are insufficient for reproducing
  8536. the packages.
  8537. @item --sources
  8538. Fetch and return the source of @var{package-or-derivation} and all their
  8539. dependencies, recursively. This is a handy way to obtain a local copy
  8540. of all the source code needed to build @var{packages}, allowing you to
  8541. eventually build them even without network access. It is an extension
  8542. of the @option{--source} option and can accept one of the following
  8543. optional argument values:
  8544. @table @code
  8545. @item package
  8546. This value causes the @option{--sources} option to behave in the same way
  8547. as the @option{--source} option.
  8548. @item all
  8549. Build the source derivations of all packages, including any source that
  8550. might be listed as @code{inputs}. This is the default value.
  8551. @example
  8552. $ guix build --sources tzdata
  8553. The following derivations will be built:
  8554. /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
  8555. /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
  8556. @end example
  8557. @item transitive
  8558. Build the source derivations of all packages, as well of all transitive
  8559. inputs to the packages. This can be used e.g.@: to
  8560. prefetch package source for later offline building.
  8561. @example
  8562. $ guix build --sources=transitive tzdata
  8563. The following derivations will be built:
  8564. /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
  8565. /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
  8566. /gnu/store/@dots{}-grep-2.21.tar.xz.drv
  8567. /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
  8568. /gnu/store/@dots{}-make-4.1.tar.xz.drv
  8569. /gnu/store/@dots{}-bash-4.3.tar.xz.drv
  8570. @dots{}
  8571. @end example
  8572. @end table
  8573. @item --system=@var{system}
  8574. @itemx -s @var{system}
  8575. Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
  8576. the system type of the build host. The @command{guix build} command allows
  8577. you to repeat this option several times, in which case it builds for all the
  8578. specified systems; other commands ignore extraneous @option{-s} options.
  8579. @quotation Note
  8580. The @option{--system} flag is for @emph{native} compilation and must not
  8581. be confused with cross-compilation. See @option{--target} below for
  8582. information on cross-compilation.
  8583. @end quotation
  8584. An example use of this is on Linux-based systems, which can emulate
  8585. different personalities. For instance, passing
  8586. @option{--system=i686-linux} on an @code{x86_64-linux} system or
  8587. @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
  8588. you to build packages in a complete 32-bit environment.
  8589. @quotation Note
  8590. Building for an @code{armhf-linux} system is unconditionally enabled on
  8591. @code{aarch64-linux} machines, although certain aarch64 chipsets do not
  8592. allow for this functionality, notably the ThunderX.
  8593. @end quotation
  8594. Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
  8595. is enabled (@pxref{Virtualization Services,
  8596. @code{qemu-binfmt-service-type}}), you can build for any system for
  8597. which a QEMU @code{binfmt_misc} handler is installed.
  8598. Builds for a system other than that of the machine you are using can
  8599. also be offloaded to a remote machine of the right architecture.
  8600. @xref{Daemon Offload Setup}, for more information on offloading.
  8601. @item --target=@var{triplet}
  8602. @cindex cross-compilation
  8603. Cross-build for @var{triplet}, which must be a valid GNU triplet, such
  8604. as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
  8605. configuration triplets,, autoconf, Autoconf}).
  8606. @anchor{build-check}
  8607. @item --check
  8608. @cindex determinism, checking
  8609. @cindex reproducibility, checking
  8610. Rebuild @var{package-or-derivation}, which are already available in the
  8611. store, and raise an error if the build results are not bit-for-bit
  8612. identical.
  8613. This mechanism allows you to check whether previously installed
  8614. substitutes are genuine (@pxref{Substitutes}), or whether the build result
  8615. of a package is deterministic. @xref{Invoking guix challenge}, for more
  8616. background information and tools.
  8617. When used in conjunction with @option{--keep-failed}, the differing
  8618. output is kept in the store, under @file{/gnu/store/@dots{}-check}.
  8619. This makes it easy to look for differences between the two results.
  8620. @item --repair
  8621. @cindex repairing store items
  8622. @cindex corruption, recovering from
  8623. Attempt to repair the specified store items, if they are corrupt, by
  8624. re-downloading or rebuilding them.
  8625. This operation is not atomic and thus restricted to @code{root}.
  8626. @item --derivations
  8627. @itemx -d
  8628. Return the derivation paths, not the output paths, of the given
  8629. packages.
  8630. @item --root=@var{file}
  8631. @itemx -r @var{file}
  8632. @cindex GC roots, adding
  8633. @cindex garbage collector roots, adding
  8634. Make @var{file} a symlink to the result, and register it as a garbage
  8635. collector root.
  8636. Consequently, the results of this @command{guix build} invocation are
  8637. protected from garbage collection until @var{file} is removed. When
  8638. that option is omitted, build results are eligible for garbage
  8639. collection as soon as the build completes. @xref{Invoking guix gc}, for
  8640. more on GC roots.
  8641. @item --log-file
  8642. @cindex build logs, access
  8643. Return the build log file names or URLs for the given
  8644. @var{package-or-derivation}, or raise an error if build logs are
  8645. missing.
  8646. This works regardless of how packages or derivations are specified. For
  8647. instance, the following invocations are equivalent:
  8648. @example
  8649. guix build --log-file `guix build -d guile`
  8650. guix build --log-file `guix build guile`
  8651. guix build --log-file guile
  8652. guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
  8653. @end example
  8654. If a log is unavailable locally, and unless @option{--no-substitutes} is
  8655. passed, the command looks for a corresponding log on one of the
  8656. substitute servers (as specified with @option{--substitute-urls}).
  8657. So for instance, imagine you want to see the build log of GDB on MIPS,
  8658. but you are actually on an @code{x86_64} machine:
  8659. @example
  8660. $ guix build --log-file gdb -s aarch64-linux
  8661. https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
  8662. @end example
  8663. You can freely access a huge library of build logs!
  8664. @end table
  8665. @node Debugging Build Failures
  8666. @subsection Debugging Build Failures
  8667. @cindex build failures, debugging
  8668. When defining a new package (@pxref{Defining Packages}), you will
  8669. probably find yourself spending some time debugging and tweaking the
  8670. build until it succeeds. To do that, you need to operate the build
  8671. commands yourself in an environment as close as possible to the one the
  8672. build daemon uses.
  8673. To that end, the first thing to do is to use the @option{--keep-failed}
  8674. or @option{-K} option of @command{guix build}, which will keep the
  8675. failed build tree in @file{/tmp} or whatever directory you specified as
  8676. @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
  8677. From there on, you can @command{cd} to the failed build tree and source
  8678. the @file{environment-variables} file, which contains all the
  8679. environment variable definitions that were in place when the build
  8680. failed. So let's say you're debugging a build failure in package
  8681. @code{foo}; a typical session would look like this:
  8682. @example
  8683. $ guix build foo -K
  8684. @dots{} @i{build fails}
  8685. $ cd /tmp/guix-build-foo.drv-0
  8686. $ source ./environment-variables
  8687. $ cd foo-1.2
  8688. @end example
  8689. Now, you can invoke commands as if you were the daemon (almost) and
  8690. troubleshoot your build process.
  8691. Sometimes it happens that, for example, a package's tests pass when you
  8692. run them manually but they fail when the daemon runs them. This can
  8693. happen because the daemon runs builds in containers where, unlike in our
  8694. environment above, network access is missing, @file{/bin/sh} does not
  8695. exist, etc. (@pxref{Build Environment Setup}).
  8696. In such cases, you may need to run inspect the build process from within
  8697. a container similar to the one the build daemon creates:
  8698. @example
  8699. $ guix build -K foo
  8700. @dots{}
  8701. $ cd /tmp/guix-build-foo.drv-0
  8702. $ guix environment --no-grafts -C foo --ad-hoc strace gdb
  8703. [env]# source ./environment-variables
  8704. [env]# cd foo-1.2
  8705. @end example
  8706. Here, @command{guix environment -C} creates a container and spawns a new
  8707. shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
  8708. strace gdb} part adds the @command{strace} and @command{gdb} commands to
  8709. the container, which you may find handy while debugging. The
  8710. @option{--no-grafts} option makes sure we get the exact same
  8711. environment, with ungrafted packages (@pxref{Security Updates}, for more
  8712. info on grafts).
  8713. To get closer to a container like that used by the build daemon, we can
  8714. remove @file{/bin/sh}:
  8715. @example
  8716. [env]# rm /bin/sh
  8717. @end example
  8718. (Don't worry, this is harmless: this is all happening in the throw-away
  8719. container created by @command{guix environment}.)
  8720. The @command{strace} command is probably not in the search path, but we
  8721. can run:
  8722. @example
  8723. [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
  8724. @end example
  8725. In this way, not only you will have reproduced the environment variables
  8726. the daemon uses, you will also be running the build process in a container
  8727. similar to the one the daemon uses.
  8728. @node Invoking guix edit
  8729. @section Invoking @command{guix edit}
  8730. @cindex @command{guix edit}
  8731. @cindex package definition, editing
  8732. So many packages, so many source files! The @command{guix edit} command
  8733. facilitates the life of users and packagers by pointing their editor at
  8734. the source file containing the definition of the specified packages.
  8735. For instance:
  8736. @example
  8737. guix edit gcc@@4.9 vim
  8738. @end example
  8739. @noindent
  8740. launches the program specified in the @env{VISUAL} or in the
  8741. @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
  8742. and that of Vim.
  8743. If you are using a Guix Git checkout (@pxref{Building from Git}), or
  8744. have created your own packages on @env{GUIX_PACKAGE_PATH}
  8745. (@pxref{Package Modules}), you will be able to edit the package
  8746. recipes. In other cases, you will be able to examine the read-only recipes
  8747. for packages currently in the store.
  8748. Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
  8749. @option{--load-path=@var{directory}} (or in short @option{-L
  8750. @var{directory}}) allows you to add @var{directory} to the front of the
  8751. package module search path and so make your own packages visible.
  8752. @node Invoking guix download
  8753. @section Invoking @command{guix download}
  8754. @cindex @command{guix download}
  8755. @cindex downloading package sources
  8756. When writing a package definition, developers typically need to download
  8757. a source tarball, compute its SHA256 hash, and write that
  8758. hash in the package definition (@pxref{Defining Packages}). The
  8759. @command{guix download} tool helps with this task: it downloads a file
  8760. from the given URI, adds it to the store, and prints both its file name
  8761. in the store and its SHA256 hash.
  8762. The fact that the downloaded file is added to the store saves bandwidth:
  8763. when the developer eventually tries to build the newly defined package
  8764. with @command{guix build}, the source tarball will not have to be
  8765. downloaded again because it is already in the store. It is also a
  8766. convenient way to temporarily stash files, which may be deleted
  8767. eventually (@pxref{Invoking guix gc}).
  8768. The @command{guix download} command supports the same URIs as used in
  8769. package definitions. In particular, it supports @code{mirror://} URIs.
  8770. @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
  8771. Guile bindings for GnuTLS are available in the user's environment; when
  8772. they are not available, an error is raised. @xref{Guile Preparations,
  8773. how to install the GnuTLS bindings for Guile,, gnutls-guile,
  8774. GnuTLS-Guile}, for more information.
  8775. @command{guix download} verifies HTTPS server certificates by loading
  8776. the certificates of X.509 authorities from the directory pointed to by
  8777. the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
  8778. Certificates}), unless @option{--no-check-certificate} is used.
  8779. The following options are available:
  8780. @table @code
  8781. @item --hash=@var{algorithm}
  8782. @itemx -H @var{algorithm}
  8783. Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
  8784. hash}, for more information.
  8785. @item --format=@var{fmt}
  8786. @itemx -f @var{fmt}
  8787. Write the hash in the format specified by @var{fmt}. For more
  8788. information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
  8789. @item --no-check-certificate
  8790. Do not validate the X.509 certificates of HTTPS servers.
  8791. When using this option, you have @emph{absolutely no guarantee} that you
  8792. are communicating with the authentic server responsible for the given
  8793. URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
  8794. @item --output=@var{file}
  8795. @itemx -o @var{file}
  8796. Save the downloaded file to @var{file} instead of adding it to the
  8797. store.
  8798. @end table
  8799. @node Invoking guix hash
  8800. @section Invoking @command{guix hash}
  8801. @cindex @command{guix hash}
  8802. The @command{guix hash} command computes the hash of a file.
  8803. It is primarily a convenience tool for anyone contributing to the
  8804. distribution: it computes the cryptographic hash of a file, which can be
  8805. used in the definition of a package (@pxref{Defining Packages}).
  8806. The general syntax is:
  8807. @example
  8808. guix hash @var{option} @var{file}
  8809. @end example
  8810. When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
  8811. hash of data read from standard input. @command{guix hash} has the
  8812. following options:
  8813. @table @code
  8814. @item --hash=@var{algorithm}
  8815. @itemx -H @var{algorithm}
  8816. Compute a hash using the specified @var{algorithm}, @code{sha256} by
  8817. default.
  8818. @var{algorithm} must the name of a cryptographic hash algorithm
  8819. supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
  8820. @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
  8821. Reference Manual}).
  8822. @item --format=@var{fmt}
  8823. @itemx -f @var{fmt}
  8824. Write the hash in the format specified by @var{fmt}.
  8825. Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
  8826. (@code{hex} and @code{hexadecimal} can be used as well).
  8827. If the @option{--format} option is not specified, @command{guix hash}
  8828. will output the hash in @code{nix-base32}. This representation is used
  8829. in the definitions of packages.
  8830. @item --recursive
  8831. @itemx -r
  8832. Compute the hash on @var{file} recursively.
  8833. In this case, the hash is computed on an archive containing @var{file},
  8834. including its children if it is a directory. Some of the metadata of
  8835. @var{file} is part of the archive; for instance, when @var{file} is a
  8836. regular file, the hash is different depending on whether @var{file} is
  8837. executable or not. Metadata such as time stamps has no impact on the
  8838. hash (@pxref{Invoking guix archive}).
  8839. @c FIXME: Replace xref above with xref to an ``Archive'' section when
  8840. @c it exists.
  8841. @item --exclude-vcs
  8842. @itemx -x
  8843. When combined with @option{--recursive}, exclude version control system
  8844. directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
  8845. @vindex git-fetch
  8846. As an example, here is how you would compute the hash of a Git checkout,
  8847. which is useful when using the @code{git-fetch} method (@pxref{origin
  8848. Reference}):
  8849. @example
  8850. $ git clone http://example.org/foo.git
  8851. $ cd foo
  8852. $ guix hash -rx .
  8853. @end example
  8854. @end table
  8855. @node Invoking guix import
  8856. @section Invoking @command{guix import}
  8857. @cindex importing packages
  8858. @cindex package import
  8859. @cindex package conversion
  8860. @cindex Invoking @command{guix import}
  8861. The @command{guix import} command is useful for people who would like to
  8862. add a package to the distribution with as little work as
  8863. possible---a legitimate demand. The command knows of a few
  8864. repositories from which it can ``import'' package metadata. The result
  8865. is a package definition, or a template thereof, in the format we know
  8866. (@pxref{Defining Packages}).
  8867. The general syntax is:
  8868. @example
  8869. guix import @var{importer} @var{options}@dots{}
  8870. @end example
  8871. @var{importer} specifies the source from which to import package
  8872. metadata, and @var{options} specifies a package identifier and other
  8873. options specific to @var{importer}.
  8874. Some of the importers rely on the ability to run the @command{gpgv} command.
  8875. For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
  8876. gnupg} if needed.
  8877. Currently, the available ``importers'' are:
  8878. @table @code
  8879. @item gnu
  8880. Import metadata for the given GNU package. This provides a template
  8881. for the latest version of that GNU package, including the hash of its
  8882. source tarball, and its canonical synopsis and description.
  8883. Additional information such as the package dependencies and its
  8884. license needs to be figured out manually.
  8885. For example, the following command returns a package definition for
  8886. GNU@tie{}Hello:
  8887. @example
  8888. guix import gnu hello
  8889. @end example
  8890. Specific command-line options are:
  8891. @table @code
  8892. @item --key-download=@var{policy}
  8893. As for @command{guix refresh}, specify the policy to handle missing
  8894. OpenPGP keys when verifying the package signature. @xref{Invoking guix
  8895. refresh, @option{--key-download}}.
  8896. @end table
  8897. @item pypi
  8898. @cindex pypi
  8899. Import metadata from the @uref{https://pypi.python.org/, Python Package
  8900. Index}. Information is taken from the JSON-formatted description
  8901. available at @code{pypi.python.org} and usually includes all the relevant
  8902. information, including package dependencies. For maximum efficiency, it
  8903. is recommended to install the @command{unzip} utility, so that the
  8904. importer can unzip Python wheels and gather data from them.
  8905. The command below imports metadata for the @code{itsdangerous} Python
  8906. package:
  8907. @example
  8908. guix import pypi itsdangerous
  8909. @end example
  8910. @table @code
  8911. @item --recursive
  8912. @itemx -r
  8913. Traverse the dependency graph of the given upstream package recursively
  8914. and generate package expressions for all those packages that are not yet
  8915. in Guix.
  8916. @end table
  8917. @item gem
  8918. @cindex gem
  8919. Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
  8920. is taken from the JSON-formatted description available at
  8921. @code{rubygems.org} and includes most relevant information, including
  8922. runtime dependencies. There are some caveats, however. The metadata
  8923. doesn't distinguish between synopses and descriptions, so the same string
  8924. is used for both fields. Additionally, the details of non-Ruby
  8925. dependencies required to build native extensions is unavailable and left
  8926. as an exercise to the packager.
  8927. The command below imports metadata for the @code{rails} Ruby package:
  8928. @example
  8929. guix import gem rails
  8930. @end example
  8931. @table @code
  8932. @item --recursive
  8933. @itemx -r
  8934. Traverse the dependency graph of the given upstream package recursively
  8935. and generate package expressions for all those packages that are not yet
  8936. in Guix.
  8937. @end table
  8938. @item cpan
  8939. @cindex CPAN
  8940. Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
  8941. Information is taken from the JSON-formatted metadata provided through
  8942. @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
  8943. relevant information, such as module dependencies. License information
  8944. should be checked closely. If Perl is available in the store, then the
  8945. @code{corelist} utility will be used to filter core modules out of the
  8946. list of dependencies.
  8947. The command command below imports metadata for the Acme::Boolean Perl
  8948. module:
  8949. @example
  8950. guix import cpan Acme::Boolean
  8951. @end example
  8952. @item cran
  8953. @cindex CRAN
  8954. @cindex Bioconductor
  8955. Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
  8956. central repository for the @uref{https://r-project.org, GNU@tie{}R
  8957. statistical and graphical environment}.
  8958. Information is extracted from the @file{DESCRIPTION} file of the package.
  8959. The command command below imports metadata for the Cairo R package:
  8960. @example
  8961. guix import cran Cairo
  8962. @end example
  8963. When @option{--recursive} is added, the importer will traverse the
  8964. dependency graph of the given upstream package recursively and generate
  8965. package expressions for all those packages that are not yet in Guix.
  8966. When @option{--style=specification} is added, the importer will generate
  8967. package definitions whose inputs are package specifications instead of
  8968. references to package variables. This is useful when generated package
  8969. definitions are to be appended to existing user modules, as the list of
  8970. used package modules need not be changed. The default is
  8971. @option{--style=variable}.
  8972. When @option{--archive=bioconductor} is added, metadata is imported from
  8973. @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
  8974. packages for the analysis and comprehension of high-throughput
  8975. genomic data in bioinformatics.
  8976. Information is extracted from the @file{DESCRIPTION} file contained in the
  8977. package archive.
  8978. The command below imports metadata for the GenomicRanges R package:
  8979. @example
  8980. guix import cran --archive=bioconductor GenomicRanges
  8981. @end example
  8982. Finally, you can also import R packages that have not yet been published on
  8983. CRAN or Bioconductor as long as they are in a git repository. Use
  8984. @option{--archive=git} followed by the URL of the git repository:
  8985. @example
  8986. guix import cran --archive=git https://github.com/immunogenomics/harmony
  8987. @end example
  8988. @item texlive
  8989. @cindex TeX Live
  8990. @cindex CTAN
  8991. Import metadata from @uref{https://www.ctan.org/, CTAN}, the
  8992. comprehensive TeX archive network for TeX packages that are part of the
  8993. @uref{https://www.tug.org/texlive/, TeX Live distribution}.
  8994. Information about the package is obtained through the XML API provided
  8995. by CTAN, while the source code is downloaded from the SVN repository of
  8996. the Tex Live project. This is done because the CTAN does not keep
  8997. versioned archives.
  8998. The command command below imports metadata for the @code{fontspec}
  8999. TeX package:
  9000. @example
  9001. guix import texlive fontspec
  9002. @end example
  9003. When @option{--archive=@var{directory}} is added, the source code is
  9004. downloaded not from the @file{latex} sub-directory of the
  9005. @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
  9006. the specified sibling @var{directory} under the same root.
  9007. The command below imports metadata for the @code{ifxetex} package from
  9008. CTAN while fetching the sources from the directory
  9009. @file{texmf/source/generic}:
  9010. @example
  9011. guix import texlive --archive=generic ifxetex
  9012. @end example
  9013. @item json
  9014. @cindex JSON, import
  9015. Import package metadata from a local JSON file. Consider the following
  9016. example package definition in JSON format:
  9017. @example
  9018. @{
  9019. "name": "hello",
  9020. "version": "2.10",
  9021. "source": "mirror://gnu/hello/hello-2.10.tar.gz",
  9022. "build-system": "gnu",
  9023. "home-page": "https://www.gnu.org/software/hello/",
  9024. "synopsis": "Hello, GNU world: An example GNU package",
  9025. "description": "GNU Hello prints a greeting.",
  9026. "license": "GPL-3.0+",
  9027. "native-inputs": ["gettext"]
  9028. @}
  9029. @end example
  9030. The field names are the same as for the @code{<package>} record
  9031. (@xref{Defining Packages}). References to other packages are provided
  9032. as JSON lists of quoted package specification strings such as
  9033. @code{guile} or @code{guile@@2.0}.
  9034. The importer also supports a more explicit source definition using the
  9035. common fields for @code{<origin>} records:
  9036. @example
  9037. @{
  9038. @dots{}
  9039. "source": @{
  9040. "method": "url-fetch",
  9041. "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
  9042. "sha256": @{
  9043. "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
  9044. @}
  9045. @}
  9046. @dots{}
  9047. @}
  9048. @end example
  9049. The command below reads metadata from the JSON file @code{hello.json}
  9050. and outputs a package expression:
  9051. @example
  9052. guix import json hello.json
  9053. @end example
  9054. @item nix
  9055. Import metadata from a local copy of the source of the
  9056. @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
  9057. relies on the @command{nix-instantiate} command of
  9058. @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
  9059. typically written in a mixture of Nix-language and Bash code. This
  9060. command only imports the high-level package structure that is written in
  9061. the Nix language. It normally includes all the basic fields of a
  9062. package definition.
  9063. When importing a GNU package, the synopsis and descriptions are replaced
  9064. by their canonical upstream variant.
  9065. Usually, you will first need to do:
  9066. @example
  9067. export NIX_REMOTE=daemon
  9068. @end example
  9069. @noindent
  9070. so that @command{nix-instantiate} does not try to open the Nix database.
  9071. As an example, the command below imports the package definition of
  9072. LibreOffice (more precisely, it imports the definition of the package
  9073. bound to the @code{libreoffice} top-level attribute):
  9074. @example
  9075. guix import nix ~/path/to/nixpkgs libreoffice
  9076. @end example
  9077. @item hackage
  9078. @cindex hackage
  9079. Import metadata from the Haskell community's central package archive
  9080. @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
  9081. Cabal files and includes all the relevant information, including package
  9082. dependencies.
  9083. Specific command-line options are:
  9084. @table @code
  9085. @item --stdin
  9086. @itemx -s
  9087. Read a Cabal file from standard input.
  9088. @item --no-test-dependencies
  9089. @itemx -t
  9090. Do not include dependencies required only by the test suites.
  9091. @item --cabal-environment=@var{alist}
  9092. @itemx -e @var{alist}
  9093. @var{alist} is a Scheme alist defining the environment in which the
  9094. Cabal conditionals are evaluated. The accepted keys are: @code{os},
  9095. @code{arch}, @code{impl} and a string representing the name of a flag.
  9096. The value associated with a flag has to be either the symbol
  9097. @code{true} or @code{false}. The value associated with other keys
  9098. has to conform to the Cabal file format definition. The default value
  9099. associated with the keys @code{os}, @code{arch} and @code{impl} is
  9100. @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
  9101. @item --recursive
  9102. @itemx -r
  9103. Traverse the dependency graph of the given upstream package recursively
  9104. and generate package expressions for all those packages that are not yet
  9105. in Guix.
  9106. @end table
  9107. The command below imports metadata for the latest version of the
  9108. HTTP Haskell package without including test dependencies and
  9109. specifying the value of the flag @samp{network-uri} as @code{false}:
  9110. @example
  9111. guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
  9112. @end example
  9113. A specific package version may optionally be specified by following the
  9114. package name by an at-sign and a version number as in the following example:
  9115. @example
  9116. guix import hackage mtl@@2.1.3.1
  9117. @end example
  9118. @item stackage
  9119. @cindex stackage
  9120. The @code{stackage} importer is a wrapper around the @code{hackage} one.
  9121. It takes a package name, looks up the package version included in a
  9122. long-term support (LTS) @uref{https://www.stackage.org, Stackage}
  9123. release and uses the @code{hackage} importer to retrieve its metadata.
  9124. Note that it is up to you to select an LTS release compatible with the
  9125. GHC compiler used by Guix.
  9126. Specific command-line options are:
  9127. @table @code
  9128. @item --no-test-dependencies
  9129. @itemx -t
  9130. Do not include dependencies required only by the test suites.
  9131. @item --lts-version=@var{version}
  9132. @itemx -l @var{version}
  9133. @var{version} is the desired LTS release version. If omitted the latest
  9134. release is used.
  9135. @item --recursive
  9136. @itemx -r
  9137. Traverse the dependency graph of the given upstream package recursively
  9138. and generate package expressions for all those packages that are not yet
  9139. in Guix.
  9140. @end table
  9141. The command below imports metadata for the HTTP Haskell package
  9142. included in the LTS Stackage release version 7.18:
  9143. @example
  9144. guix import stackage --lts-version=7.18 HTTP
  9145. @end example
  9146. @item elpa
  9147. @cindex elpa
  9148. Import metadata from an Emacs Lisp Package Archive (ELPA) package
  9149. repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
  9150. Specific command-line options are:
  9151. @table @code
  9152. @item --archive=@var{repo}
  9153. @itemx -a @var{repo}
  9154. @var{repo} identifies the archive repository from which to retrieve the
  9155. information. Currently the supported repositories and their identifiers
  9156. are:
  9157. @itemize -
  9158. @item
  9159. @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
  9160. identifier. This is the default.
  9161. Packages from @code{elpa.gnu.org} are signed with one of the keys
  9162. contained in the GnuPG keyring at
  9163. @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
  9164. @code{emacs} package (@pxref{Package Installation, ELPA package
  9165. signatures,, emacs, The GNU Emacs Manual}).
  9166. @item
  9167. @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
  9168. @code{melpa-stable} identifier.
  9169. @item
  9170. @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
  9171. identifier.
  9172. @end itemize
  9173. @item --recursive
  9174. @itemx -r
  9175. Traverse the dependency graph of the given upstream package recursively
  9176. and generate package expressions for all those packages that are not yet
  9177. in Guix.
  9178. @end table
  9179. @item crate
  9180. @cindex crate
  9181. Import metadata from the crates.io Rust package repository
  9182. @uref{https://crates.io, crates.io}, as in this example:
  9183. @example
  9184. guix import crate blake2-rfc
  9185. @end example
  9186. The crate importer also allows you to specify a version string:
  9187. @example
  9188. guix import crate constant-time-eq@@0.1.0
  9189. @end example
  9190. Additional options include:
  9191. @table @code
  9192. @item --recursive
  9193. @itemx -r
  9194. Traverse the dependency graph of the given upstream package recursively
  9195. and generate package expressions for all those packages that are not yet
  9196. in Guix.
  9197. @end table
  9198. @item opam
  9199. @cindex OPAM
  9200. @cindex OCaml
  9201. Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
  9202. repository used by the OCaml community.
  9203. Additional options include:
  9204. @table @code
  9205. @item --recursive
  9206. @itemx -r
  9207. Traverse the dependency graph of the given upstream package recursively
  9208. and generate package expressions for all those packages that are not yet
  9209. in Guix.
  9210. @item --repo
  9211. Select the given repository (a repository name). Possible values include:
  9212. @itemize
  9213. @item @code{opam}, the default opam repository,
  9214. @item @code{coq} or @code{coq-released}, the stable repository for coq packages,
  9215. @item @code{coq-core-dev}, the repository that contains development versions of coq,
  9216. @item @code{coq-extra-dev}, the repository that contains development versions
  9217. of coq packages.
  9218. @end itemize
  9219. @end table
  9220. @end table
  9221. The structure of the @command{guix import} code is modular. It would be
  9222. useful to have more importers for other package formats, and your help
  9223. is welcome here (@pxref{Contributing}).
  9224. @node Invoking guix refresh
  9225. @section Invoking @command{guix refresh}
  9226. @cindex @command {guix refresh}
  9227. The primary audience of the @command{guix refresh} command is developers
  9228. of the GNU software distribution. By default, it reports any packages
  9229. provided by the distribution that are outdated compared to the latest
  9230. upstream version, like this:
  9231. @example
  9232. $ guix refresh
  9233. gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
  9234. gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
  9235. @end example
  9236. Alternatively, one can specify packages to consider, in which case a
  9237. warning is emitted for packages that lack an updater:
  9238. @example
  9239. $ guix refresh coreutils guile guile-ssh
  9240. gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
  9241. gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
  9242. @end example
  9243. @command{guix refresh} browses the upstream repository of each package and determines
  9244. the highest version number of the releases therein. The command
  9245. knows how to update specific types of packages: GNU packages, ELPA
  9246. packages, etc.---see the documentation for @option{--type} below. There
  9247. are many packages, though, for which it lacks a method to determine
  9248. whether a new upstream release is available. However, the mechanism is
  9249. extensible, so feel free to get in touch with us to add a new method!
  9250. @table @code
  9251. @item --recursive
  9252. Consider the packages specified, and all the packages upon which they depend.
  9253. @example
  9254. $ guix refresh --recursive coreutils
  9255. gnu/packages/acl.scm:35:2: warning: no updater for acl
  9256. gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
  9257. gnu/packages/xml.scm:68:2: warning: no updater for expat
  9258. gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
  9259. @dots{}
  9260. @end example
  9261. @end table
  9262. Sometimes the upstream name differs from the package name used in Guix,
  9263. and @command{guix refresh} needs a little help. Most updaters honor the
  9264. @code{upstream-name} property in package definitions, which can be used
  9265. to that effect:
  9266. @lisp
  9267. (define-public network-manager
  9268. (package
  9269. (name "network-manager")
  9270. ;; @dots{}
  9271. (properties '((upstream-name . "NetworkManager")))))
  9272. @end lisp
  9273. When passed @option{--update}, it modifies distribution source files to
  9274. update the version numbers and source tarball hashes of those package
  9275. recipes (@pxref{Defining Packages}). This is achieved by downloading
  9276. each package's latest source tarball and its associated OpenPGP
  9277. signature, authenticating the downloaded tarball against its signature
  9278. using @command{gpgv}, and finally computing its hash---note that GnuPG must be
  9279. installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
  9280. When the public
  9281. key used to sign the tarball is missing from the user's keyring, an
  9282. attempt is made to automatically retrieve it from a public key server;
  9283. when this is successful, the key is added to the user's keyring; otherwise,
  9284. @command{guix refresh} reports an error.
  9285. The following options are supported:
  9286. @table @code
  9287. @item --expression=@var{expr}
  9288. @itemx -e @var{expr}
  9289. Consider the package @var{expr} evaluates to.
  9290. This is useful to precisely refer to a package, as in this example:
  9291. @example
  9292. guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
  9293. @end example
  9294. This command lists the dependents of the ``final'' libc (essentially all
  9295. the packages).
  9296. @item --update
  9297. @itemx -u
  9298. Update distribution source files (package recipes) in place. This is
  9299. usually run from a checkout of the Guix source tree (@pxref{Running
  9300. Guix Before It Is Installed}):
  9301. @example
  9302. $ ./pre-inst-env guix refresh -s non-core -u
  9303. @end example
  9304. @xref{Defining Packages}, for more information on package definitions.
  9305. @item --select=[@var{subset}]
  9306. @itemx -s @var{subset}
  9307. Select all the packages in @var{subset}, one of @code{core} or
  9308. @code{non-core}.
  9309. The @code{core} subset refers to all the packages at the core of the
  9310. distribution---i.e., packages that are used to build ``everything
  9311. else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
  9312. changing one of these packages in the distribution entails a rebuild of
  9313. all the others. Thus, such updates are an inconvenience to users in
  9314. terms of build time or bandwidth used to achieve the upgrade.
  9315. The @code{non-core} subset refers to the remaining packages. It is
  9316. typically useful in cases where an update of the core packages would be
  9317. inconvenient.
  9318. @item --manifest=@var{file}
  9319. @itemx -m @var{file}
  9320. Select all the packages from the manifest in @var{file}. This is useful to
  9321. check if any packages of the user manifest can be updated.
  9322. @item --type=@var{updater}
  9323. @itemx -t @var{updater}
  9324. Select only packages handled by @var{updater} (may be a comma-separated
  9325. list of updaters). Currently, @var{updater} may be one of:
  9326. @table @code
  9327. @item gnu
  9328. the updater for GNU packages;
  9329. @item savannah
  9330. the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
  9331. @item gnome
  9332. the updater for GNOME packages;
  9333. @item kde
  9334. the updater for KDE packages;
  9335. @item xorg
  9336. the updater for X.org packages;
  9337. @item kernel.org
  9338. the updater for packages hosted on kernel.org;
  9339. @item elpa
  9340. the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
  9341. @item cran
  9342. the updater for @uref{https://cran.r-project.org/, CRAN} packages;
  9343. @item bioconductor
  9344. the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
  9345. @item cpan
  9346. the updater for @uref{https://www.cpan.org/, CPAN} packages;
  9347. @item pypi
  9348. the updater for @uref{https://pypi.python.org, PyPI} packages.
  9349. @item gem
  9350. the updater for @uref{https://rubygems.org, RubyGems} packages.
  9351. @item github
  9352. the updater for @uref{https://github.com, GitHub} packages.
  9353. @item hackage
  9354. the updater for @uref{https://hackage.haskell.org, Hackage} packages.
  9355. @item stackage
  9356. the updater for @uref{https://www.stackage.org, Stackage} packages.
  9357. @item crate
  9358. the updater for @uref{https://crates.io, Crates} packages.
  9359. @item launchpad
  9360. the updater for @uref{https://launchpad.net, Launchpad} packages.
  9361. @end table
  9362. For instance, the following command only checks for updates of Emacs
  9363. packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
  9364. @example
  9365. $ guix refresh --type=elpa,cran
  9366. gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
  9367. gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
  9368. @end example
  9369. @end table
  9370. In addition, @command{guix refresh} can be passed one or more package
  9371. names, as in this example:
  9372. @example
  9373. $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
  9374. @end example
  9375. @noindent
  9376. The command above specifically updates the @code{emacs} and
  9377. @code{idutils} packages. The @option{--select} option would have no
  9378. effect in this case.
  9379. When considering whether to upgrade a package, it is sometimes
  9380. convenient to know which packages would be affected by the upgrade and
  9381. should be checked for compatibility. For this the following option may
  9382. be used when passing @command{guix refresh} one or more package names:
  9383. @table @code
  9384. @item --list-updaters
  9385. @itemx -L
  9386. List available updaters and exit (see @option{--type} above).
  9387. For each updater, display the fraction of packages it covers; at the
  9388. end, display the fraction of packages covered by all these updaters.
  9389. @item --list-dependent
  9390. @itemx -l
  9391. List top-level dependent packages that would need to be rebuilt as a
  9392. result of upgrading one or more packages.
  9393. @xref{Invoking guix graph, the @code{reverse-package} type of
  9394. @command{guix graph}}, for information on how to visualize the list of
  9395. dependents of a package.
  9396. @end table
  9397. Be aware that the @option{--list-dependent} option only
  9398. @emph{approximates} the rebuilds that would be required as a result of
  9399. an upgrade. More rebuilds might be required under some circumstances.
  9400. @example
  9401. $ guix refresh --list-dependent flex
  9402. Building the following 120 packages would ensure 213 dependent packages are rebuilt:
  9403. hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
  9404. @end example
  9405. The command above lists a set of packages that could be built to check
  9406. for compatibility with an upgraded @code{flex} package.
  9407. @table @code
  9408. @item --list-transitive
  9409. List all the packages which one or more packages depend upon.
  9410. @example
  9411. $ guix refresh --list-transitive flex
  9412. flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
  9413. 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{}
  9414. @end example
  9415. @end table
  9416. The command above lists a set of packages which, when changed, would cause
  9417. @code{flex} to be rebuilt.
  9418. The following options can be used to customize GnuPG operation:
  9419. @table @code
  9420. @item --gpg=@var{command}
  9421. Use @var{command} as the GnuPG 2.x command. @var{command} is searched
  9422. for in @code{$PATH}.
  9423. @item --keyring=@var{file}
  9424. Use @var{file} as the keyring for upstream keys. @var{file} must be in the
  9425. @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
  9426. and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
  9427. (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
  9428. information on a tool to manipulate keybox files).
  9429. When this option is omitted, @command{guix refresh} uses
  9430. @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
  9431. signing keys. OpenPGP signatures are checked against keys from this keyring;
  9432. missing keys are downloaded to this keyring as well (see
  9433. @option{--key-download} below).
  9434. You can export keys from your default GPG keyring into a keybox file using
  9435. commands like this one:
  9436. @example
  9437. gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
  9438. @end example
  9439. Likewise, you can fetch keys to a specific keybox file like this:
  9440. @example
  9441. gpg --no-default-keyring --keyring mykeyring.kbx \
  9442. --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
  9443. @end example
  9444. @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
  9445. Privacy Guard}, for more information on GPG's @option{--keyring} option.
  9446. @item --key-download=@var{policy}
  9447. Handle missing OpenPGP keys according to @var{policy}, which may be one
  9448. of:
  9449. @table @code
  9450. @item always
  9451. Always download missing OpenPGP keys from the key server, and add them
  9452. to the user's GnuPG keyring.
  9453. @item never
  9454. Never try to download missing OpenPGP keys. Instead just bail out.
  9455. @item interactive
  9456. When a package signed with an unknown OpenPGP key is encountered, ask
  9457. the user whether to download it or not. This is the default behavior.
  9458. @end table
  9459. @item --key-server=@var{host}
  9460. Use @var{host} as the OpenPGP key server when importing a public key.
  9461. @item --load-path=@var{directory}
  9462. Add @var{directory} to the front of the package module search path
  9463. (@pxref{Package Modules}).
  9464. This allows users to define their own packages and make them visible to
  9465. the command-line tools.
  9466. @end table
  9467. The @code{github} updater uses the
  9468. @uref{https://developer.github.com/v3/, GitHub API} to query for new
  9469. releases. When used repeatedly e.g.@: when refreshing all packages,
  9470. GitHub will eventually refuse to answer any further API requests. By
  9471. default 60 API requests per hour are allowed, and a full refresh on all
  9472. GitHub packages in Guix requires more than this. Authentication with
  9473. GitHub through the use of an API token alleviates these limits. To use
  9474. an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
  9475. token procured from @uref{https://github.com/settings/tokens} or
  9476. otherwise.
  9477. @node Invoking guix lint
  9478. @section Invoking @command{guix lint}
  9479. @cindex @command{guix lint}
  9480. @cindex package, checking for errors
  9481. The @command{guix lint} command is meant to help package developers avoid
  9482. common errors and use a consistent style. It runs a number of checks on
  9483. a given set of packages in order to find common mistakes in their
  9484. definitions. Available @dfn{checkers} include (see
  9485. @option{--list-checkers} for a complete list):
  9486. @table @code
  9487. @item synopsis
  9488. @itemx description
  9489. Validate certain typographical and stylistic rules about package
  9490. descriptions and synopses.
  9491. @item inputs-should-be-native
  9492. Identify inputs that should most likely be native inputs.
  9493. @item source
  9494. @itemx home-page
  9495. @itemx mirror-url
  9496. @itemx github-url
  9497. @itemx source-file-name
  9498. Probe @code{home-page} and @code{source} URLs and report those that are
  9499. invalid. Suggest a @code{mirror://} URL when applicable. If the
  9500. @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
  9501. URL@. Check that the source file name is meaningful, e.g.@: is not just a
  9502. version number or ``git-checkout'', without a declared @code{file-name}
  9503. (@pxref{origin Reference}).
  9504. @item source-unstable-tarball
  9505. Parse the @code{source} URL to determine if a tarball from GitHub is
  9506. autogenerated or if it is a release tarball. Unfortunately GitHub's
  9507. autogenerated tarballs are sometimes regenerated.
  9508. @item derivation
  9509. Check that the derivation of the given packages can be successfully
  9510. computed for all the supported systems (@pxref{Derivations}).
  9511. @item profile-collisions
  9512. Check whether installing the given packages in a profile would lead to
  9513. collisions. Collisions occur when several packages with the same name
  9514. but a different version or a different store file name are propagated.
  9515. @xref{package Reference, @code{propagated-inputs}}, for more information
  9516. on propagated inputs.
  9517. @item archival
  9518. @cindex Software Heritage, source code archive
  9519. @cindex archival of source code, Software Heritage
  9520. Checks whether the package's source code is archived at
  9521. @uref{https://www.softwareheritage.org, Software Heritage}.
  9522. When the source code that is not archived comes from a version-control system
  9523. (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
  9524. ``save'' request so that it eventually archives it. This ensures that the
  9525. source will remain available in the long term, and that Guix can fall back to
  9526. Software Heritage should the source code disappear from its original host.
  9527. The status of recent ``save'' requests can be
  9528. @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
  9529. When source code is a tarball obtained with @code{url-fetch}, simply print a
  9530. message when it is not archived. As of this writing, Software Heritage does
  9531. not allow requests to save arbitrary tarballs; we are working on ways to
  9532. ensure that non-VCS source code is also archived.
  9533. Software Heritage
  9534. @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
  9535. request rate per IP address}. When the limit is reached, @command{guix lint}
  9536. prints a message and the @code{archival} checker stops doing anything until
  9537. that limit has been reset.
  9538. @item cve
  9539. @cindex security vulnerabilities
  9540. @cindex CVE, Common Vulnerabilities and Exposures
  9541. Report known vulnerabilities found in the Common Vulnerabilities and
  9542. Exposures (CVE) databases of the current and past year
  9543. @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
  9544. NIST}.
  9545. To view information about a particular vulnerability, visit pages such as:
  9546. @itemize
  9547. @item
  9548. @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
  9549. @item
  9550. @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
  9551. @end itemize
  9552. @noindent
  9553. where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
  9554. @code{CVE-2015-7554}.
  9555. Package developers can specify in package recipes the
  9556. @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
  9557. name and version of the package when they differ from the name or version
  9558. that Guix uses, as in this example:
  9559. @lisp
  9560. (package
  9561. (name "grub")
  9562. ;; @dots{}
  9563. ;; CPE calls this package "grub2".
  9564. (properties '((cpe-name . "grub2")
  9565. (cpe-version . "2.3"))))
  9566. @end lisp
  9567. @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
  9568. Some entries in the CVE database do not specify which version of a
  9569. package they apply to, and would thus ``stick around'' forever. Package
  9570. developers who found CVE alerts and verified they can be ignored can
  9571. declare them as in this example:
  9572. @lisp
  9573. (package
  9574. (name "t1lib")
  9575. ;; @dots{}
  9576. ;; These CVEs no longer apply and can be safely ignored.
  9577. (properties `((lint-hidden-cve . ("CVE-2011-0433"
  9578. "CVE-2011-1553"
  9579. "CVE-2011-1554"
  9580. "CVE-2011-5244")))))
  9581. @end lisp
  9582. @item formatting
  9583. Warn about obvious source code formatting issues: trailing white space,
  9584. use of tabulations, etc.
  9585. @end table
  9586. The general syntax is:
  9587. @example
  9588. guix lint @var{options} @var{package}@dots{}
  9589. @end example
  9590. If no package is given on the command line, then all packages are checked.
  9591. The @var{options} may be zero or more of the following:
  9592. @table @code
  9593. @item --list-checkers
  9594. @itemx -l
  9595. List and describe all the available checkers that will be run on packages
  9596. and exit.
  9597. @item --checkers
  9598. @itemx -c
  9599. Only enable the checkers specified in a comma-separated list using the
  9600. names returned by @option{--list-checkers}.
  9601. @item --exclude
  9602. @itemx -x
  9603. Only disable the checkers specified in a comma-separated list using the
  9604. names returned by @option{--list-checkers}.
  9605. @item --no-network
  9606. @itemx -n
  9607. Only enable the checkers that do not depend on Internet access.
  9608. @item --load-path=@var{directory}
  9609. @itemx -L @var{directory}
  9610. Add @var{directory} to the front of the package module search path
  9611. (@pxref{Package Modules}).
  9612. This allows users to define their own packages and make them visible to
  9613. the command-line tools.
  9614. @end table
  9615. @node Invoking guix size
  9616. @section Invoking @command{guix size}
  9617. @cindex size
  9618. @cindex package size
  9619. @cindex closure
  9620. @cindex @command{guix size}
  9621. The @command{guix size} command helps package developers profile the
  9622. disk usage of packages. It is easy to overlook the impact of an
  9623. additional dependency added to a package, or the impact of using a
  9624. single output for a package that could easily be split (@pxref{Packages
  9625. with Multiple Outputs}). Such are the typical issues that
  9626. @command{guix size} can highlight.
  9627. The command can be passed one or more package specifications
  9628. such as @code{gcc@@4.8}
  9629. or @code{guile:debug}, or a file name in the store. Consider this
  9630. example:
  9631. @example
  9632. $ guix size coreutils
  9633. store item total self
  9634. /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
  9635. /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
  9636. /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
  9637. /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
  9638. /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
  9639. /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
  9640. /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
  9641. /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
  9642. total: 78.9 MiB
  9643. @end example
  9644. @cindex closure
  9645. The store items listed here constitute the @dfn{transitive closure} of
  9646. Coreutils---i.e., Coreutils and all its dependencies, recursively---as
  9647. would be returned by:
  9648. @example
  9649. $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
  9650. @end example
  9651. Here the output shows three columns next to store items. The first column,
  9652. labeled ``total'', shows the size in mebibytes (MiB) of the closure of
  9653. the store item---that is, its own size plus the size of all its
  9654. dependencies. The next column, labeled ``self'', shows the size of the
  9655. item itself. The last column shows the ratio of the size of the item
  9656. itself to the space occupied by all the items listed here.
  9657. In this example, we see that the closure of Coreutils weighs in at
  9658. 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
  9659. libraries. (That libc and GCC's libraries represent a large fraction of
  9660. the closure is not a problem @i{per se} because they are always available
  9661. on the system anyway.)
  9662. Since the command also accepts store file names, assessing the size of
  9663. a build result is straightforward:
  9664. @example
  9665. guix size $(guix system build config.scm)
  9666. @end example
  9667. When the package(s) passed to @command{guix size} are available in the
  9668. store@footnote{More precisely, @command{guix size} looks for the
  9669. @emph{ungrafted} variant of the given package(s), as returned by
  9670. @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
  9671. for information on grafts.}, @command{guix size} queries the daemon to determine its
  9672. dependencies, and measures its size in the store, similar to @command{du
  9673. -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
  9674. Coreutils}).
  9675. When the given packages are @emph{not} in the store, @command{guix size}
  9676. reports information based on the available substitutes
  9677. (@pxref{Substitutes}). This makes it possible it to profile disk usage of
  9678. store items that are not even on disk, only available remotely.
  9679. You can also specify several package names:
  9680. @example
  9681. $ guix size coreutils grep sed bash
  9682. store item total self
  9683. /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
  9684. /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
  9685. /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
  9686. /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
  9687. @dots{}
  9688. total: 102.3 MiB
  9689. @end example
  9690. @noindent
  9691. In this example we see that the combination of the four packages takes
  9692. 102.3@tie{}MiB in total, which is much less than the sum of each closure
  9693. since they have a lot of dependencies in common.
  9694. When looking at the profile returned by @command{guix size}, you may
  9695. find yourself wondering why a given package shows up in the profile at
  9696. all. To understand it, you can use @command{guix graph --path -t
  9697. references} to display the shortest path between the two packages
  9698. (@pxref{Invoking guix graph}).
  9699. The available options are:
  9700. @table @option
  9701. @item --substitute-urls=@var{urls}
  9702. Use substitute information from @var{urls}.
  9703. @xref{client-substitute-urls, the same option for @code{guix build}}.
  9704. @item --sort=@var{key}
  9705. Sort lines according to @var{key}, one of the following options:
  9706. @table @code
  9707. @item self
  9708. the size of each item (the default);
  9709. @item closure
  9710. the total size of the item's closure.
  9711. @end table
  9712. @item --map-file=@var{file}
  9713. Write a graphical map of disk usage in PNG format to @var{file}.
  9714. For the example above, the map looks like this:
  9715. @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
  9716. produced by @command{guix size}}
  9717. This option requires that
  9718. @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
  9719. installed and visible in Guile's module search path. When that is not
  9720. the case, @command{guix size} fails as it tries to load it.
  9721. @item --system=@var{system}
  9722. @itemx -s @var{system}
  9723. Consider packages for @var{system}---e.g., @code{x86_64-linux}.
  9724. @item --load-path=@var{directory}
  9725. @itemx -L @var{directory}
  9726. Add @var{directory} to the front of the package module search path
  9727. (@pxref{Package Modules}).
  9728. This allows users to define their own packages and make them visible to
  9729. the command-line tools.
  9730. @end table
  9731. @node Invoking guix graph
  9732. @section Invoking @command{guix graph}
  9733. @cindex DAG
  9734. @cindex @command{guix graph}
  9735. @cindex package dependencies
  9736. Packages and their dependencies form a @dfn{graph}, specifically a
  9737. directed acyclic graph (DAG). It can quickly become difficult to have a
  9738. mental model of the package DAG, so the @command{guix graph} command
  9739. provides a visual representation of the DAG@. By default,
  9740. @command{guix graph} emits a DAG representation in the input format of
  9741. @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
  9742. directly to the @command{dot} command of Graphviz. It can also emit an
  9743. HTML page with embedded JavaScript code to display a ``chord diagram''
  9744. in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
  9745. emit Cypher queries to construct a graph in a graph database supporting
  9746. the @uref{https://www.opencypher.org/, openCypher} query language. With
  9747. @option{--path}, it simply displays the shortest path between two
  9748. packages. The general syntax is:
  9749. @example
  9750. guix graph @var{options} @var{package}@dots{}
  9751. @end example
  9752. For example, the following command generates a PDF file representing the
  9753. package DAG for the GNU@tie{}Core Utilities, showing its build-time
  9754. dependencies:
  9755. @example
  9756. guix graph coreutils | dot -Tpdf > dag.pdf
  9757. @end example
  9758. The output looks like this:
  9759. @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
  9760. Nice little graph, no?
  9761. You may find it more pleasant to navigate the graph interactively with
  9762. @command{xdot} (from the @code{xdot} package):
  9763. @example
  9764. guix graph coreutils | xdot -
  9765. @end example
  9766. But there is more than one graph! The one above is concise: it is the
  9767. graph of package objects, omitting implicit inputs such as GCC, libc,
  9768. grep, etc. It is often useful to have such a concise graph, but
  9769. sometimes one may want to see more details. @command{guix graph} supports
  9770. several types of graphs, allowing you to choose the level of detail:
  9771. @table @code
  9772. @item package
  9773. This is the default type used in the example above. It shows the DAG of
  9774. package objects, excluding implicit dependencies. It is concise, but
  9775. filters out many details.
  9776. @item reverse-package
  9777. This shows the @emph{reverse} DAG of packages. For example:
  9778. @example
  9779. guix graph --type=reverse-package ocaml
  9780. @end example
  9781. ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
  9782. you are also interested in cases where OCaml is an implicit dependency, see
  9783. @code{reverse-bag} below).
  9784. Note that for core packages this can yield huge graphs. If all you want
  9785. is to know the number of packages that depend on a given package, use
  9786. @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
  9787. @option{--list-dependent}}).
  9788. @item bag-emerged
  9789. This is the package DAG, @emph{including} implicit inputs.
  9790. For instance, the following command:
  9791. @example
  9792. guix graph --type=bag-emerged coreutils
  9793. @end example
  9794. ...@: yields this bigger graph:
  9795. @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
  9796. At the bottom of the graph, we see all the implicit inputs of
  9797. @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
  9798. Now, note that the dependencies of these implicit inputs---that is, the
  9799. @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
  9800. here, for conciseness.
  9801. @item bag
  9802. Similar to @code{bag-emerged}, but this time including all the bootstrap
  9803. dependencies.
  9804. @item bag-with-origins
  9805. Similar to @code{bag}, but also showing origins and their dependencies.
  9806. @item reverse-bag
  9807. This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
  9808. it also takes implicit dependencies into account. For example:
  9809. @example
  9810. guix graph -t reverse-bag dune
  9811. @end example
  9812. @noindent
  9813. ...@: yields the graph of all packages that depend on Dune, directly or
  9814. indirectly. Since Dune is an @emph{implicit} dependency of many packages
  9815. @i{via} @code{dune-build-system}, this shows a large number of packages,
  9816. whereas @code{reverse-package} would show very few if any.
  9817. @item derivation
  9818. This is the most detailed representation: It shows the DAG of
  9819. derivations (@pxref{Derivations}) and plain store items. Compared to
  9820. the above representation, many additional nodes are visible, including
  9821. build scripts, patches, Guile modules, etc.
  9822. For this type of graph, it is also possible to pass a @file{.drv} file
  9823. name instead of a package name, as in:
  9824. @example
  9825. guix graph -t derivation `guix system build -d my-config.scm`
  9826. @end example
  9827. @item module
  9828. This is the graph of @dfn{package modules} (@pxref{Package Modules}).
  9829. For example, the following command shows the graph for the package
  9830. module that defines the @code{guile} package:
  9831. @example
  9832. guix graph -t module guile | xdot -
  9833. @end example
  9834. @end table
  9835. All the types above correspond to @emph{build-time dependencies}. The
  9836. following graph type represents the @emph{run-time dependencies}:
  9837. @table @code
  9838. @item references
  9839. This is the graph of @dfn{references} of a package output, as returned
  9840. by @command{guix gc --references} (@pxref{Invoking guix gc}).
  9841. If the given package output is not available in the store, @command{guix
  9842. graph} attempts to obtain dependency information from substitutes.
  9843. Here you can also pass a store file name instead of a package name. For
  9844. example, the command below produces the reference graph of your profile
  9845. (which can be big!):
  9846. @example
  9847. guix graph -t references `readlink -f ~/.guix-profile`
  9848. @end example
  9849. @item referrers
  9850. This is the graph of the @dfn{referrers} of a store item, as returned by
  9851. @command{guix gc --referrers} (@pxref{Invoking guix gc}).
  9852. This relies exclusively on local information from your store. For
  9853. instance, let us suppose that the current Inkscape is available in 10
  9854. profiles on your machine; @command{guix graph -t referrers inkscape}
  9855. will show a graph rooted at Inkscape and with those 10 profiles linked
  9856. to it.
  9857. It can help determine what is preventing a store item from being garbage
  9858. collected.
  9859. @end table
  9860. @cindex shortest path, between packages
  9861. Often, the graph of the package you are interested in does not fit on
  9862. your screen, and anyway all you want to know is @emph{why} that package
  9863. actually depends on some seemingly unrelated package. The
  9864. @option{--path} option instructs @command{guix graph} to display the
  9865. shortest path between two packages (or derivations, or store items,
  9866. etc.):
  9867. @example
  9868. $ guix graph --path emacs libunistring
  9869. emacs@@26.3
  9870. mailutils@@3.9
  9871. libunistring@@0.9.10
  9872. $ guix graph --path -t derivation emacs libunistring
  9873. /gnu/store/@dots{}-emacs-26.3.drv
  9874. /gnu/store/@dots{}-mailutils-3.9.drv
  9875. /gnu/store/@dots{}-libunistring-0.9.10.drv
  9876. $ guix graph --path -t references emacs libunistring
  9877. /gnu/store/@dots{}-emacs-26.3
  9878. /gnu/store/@dots{}-libidn2-2.2.0
  9879. /gnu/store/@dots{}-libunistring-0.9.10
  9880. @end example
  9881. The available options are the following:
  9882. @table @option
  9883. @item --type=@var{type}
  9884. @itemx -t @var{type}
  9885. Produce a graph output of @var{type}, where @var{type} must be one of
  9886. the values listed above.
  9887. @item --list-types
  9888. List the supported graph types.
  9889. @item --backend=@var{backend}
  9890. @itemx -b @var{backend}
  9891. Produce a graph using the selected @var{backend}.
  9892. @item --list-backends
  9893. List the supported graph backends.
  9894. Currently, the available backends are Graphviz and d3.js.
  9895. @item --path
  9896. Display the shortest path between two nodes of the type specified by
  9897. @option{--type}. The example below shows the shortest path between
  9898. @code{libreoffice} and @code{llvm} according to the references of
  9899. @code{libreoffice}:
  9900. @example
  9901. $ guix graph --path -t references libreoffice llvm
  9902. /gnu/store/@dots{}-libreoffice-6.4.2.2
  9903. /gnu/store/@dots{}-libepoxy-1.5.4
  9904. /gnu/store/@dots{}-mesa-19.3.4
  9905. /gnu/store/@dots{}-llvm-9.0.1
  9906. @end example
  9907. @item --expression=@var{expr}
  9908. @itemx -e @var{expr}
  9909. Consider the package @var{expr} evaluates to.
  9910. This is useful to precisely refer to a package, as in this example:
  9911. @example
  9912. guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
  9913. @end example
  9914. @item --system=@var{system}
  9915. @itemx -s @var{system}
  9916. Display the graph for @var{system}---e.g., @code{i686-linux}.
  9917. The package dependency graph is largely architecture-independent, but there
  9918. are some architecture-dependent bits that this option allows you to visualize.
  9919. @item --load-path=@var{directory}
  9920. @itemx -L @var{directory}
  9921. Add @var{directory} to the front of the package module search path
  9922. (@pxref{Package Modules}).
  9923. This allows users to define their own packages and make them visible to
  9924. the command-line tools.
  9925. @end table
  9926. On top of that, @command{guix graph} supports all the usual package
  9927. transformation options (@pxref{Package Transformation Options}). This
  9928. makes it easy to view the effect of a graph-rewriting transformation
  9929. such as @option{--with-input}. For example, the command below outputs
  9930. the graph of @code{git} once @code{openssl} has been replaced by
  9931. @code{libressl} everywhere in the graph:
  9932. @example
  9933. guix graph git --with-input=openssl=libressl
  9934. @end example
  9935. So many possibilities, so much fun!
  9936. @node Invoking guix publish
  9937. @section Invoking @command{guix publish}
  9938. @cindex @command{guix publish}
  9939. The purpose of @command{guix publish} is to enable users to easily share
  9940. their store with others, who can then use it as a substitute server
  9941. (@pxref{Substitutes}).
  9942. When @command{guix publish} runs, it spawns an HTTP server which allows
  9943. anyone with network access to obtain substitutes from it. This means
  9944. that any machine running Guix can also act as if it were a build farm,
  9945. since the HTTP interface is compatible with Cuirass, the software behind
  9946. the @code{@value{SUBSTITUTE-SERVER}} build farm.
  9947. For security, each substitute is signed, allowing recipients to check
  9948. their authenticity and integrity (@pxref{Substitutes}). Because
  9949. @command{guix publish} uses the signing key of the system, which is only
  9950. readable by the system administrator, it must be started as root; the
  9951. @option{--user} option makes it drop root privileges early on.
  9952. The signing key pair must be generated before @command{guix publish} is
  9953. launched, using @command{guix archive --generate-key} (@pxref{Invoking
  9954. guix archive}).
  9955. When the @option{--advertise} option is passed, the server advertises
  9956. its availability on the local network using multicast DNS (mDNS) and DNS
  9957. service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
  9958. guile-avahi, Using Avahi in Guile Scheme Programs}).
  9959. The general syntax is:
  9960. @example
  9961. guix publish @var{options}@dots{}
  9962. @end example
  9963. Running @command{guix publish} without any additional arguments will
  9964. spawn an HTTP server on port 8080:
  9965. @example
  9966. guix publish
  9967. @end example
  9968. Once a publishing server has been authorized, the daemon may download
  9969. substitutes from it. @xref{Getting Substitutes from Other Servers}.
  9970. By default, @command{guix publish} compresses archives on the fly as it
  9971. serves them. This ``on-the-fly'' mode is convenient in that it requires
  9972. no setup and is immediately available. However, when serving lots of
  9973. clients, we recommend using the @option{--cache} option, which enables
  9974. caching of the archives before they are sent to clients---see below for
  9975. details. The @command{guix weather} command provides a handy way to
  9976. check what a server provides (@pxref{Invoking guix weather}).
  9977. As a bonus, @command{guix publish} also serves as a content-addressed
  9978. mirror for source files referenced in @code{origin} records
  9979. (@pxref{origin Reference}). For instance, assuming @command{guix
  9980. publish} is running on @code{example.org}, the following URL returns the
  9981. raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
  9982. (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
  9983. @example
  9984. http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
  9985. @end example
  9986. Obviously, these URLs only work for files that are in the store; in
  9987. other cases, they return 404 (``Not Found'').
  9988. @cindex build logs, publication
  9989. Build logs are available from @code{/log} URLs like:
  9990. @example
  9991. http://example.org/log/gwspk@dots{}-guile-2.2.3
  9992. @end example
  9993. @noindent
  9994. When @command{guix-daemon} is configured to save compressed build logs,
  9995. as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
  9996. URLs return the compressed log as-is, with an appropriate
  9997. @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
  9998. running @command{guix-daemon} with @option{--log-compression=gzip} since
  9999. Web browsers can automatically decompress it, which is not the case with
  10000. Bzip2 compression.
  10001. The following options are available:
  10002. @table @code
  10003. @item --port=@var{port}
  10004. @itemx -p @var{port}
  10005. Listen for HTTP requests on @var{port}.
  10006. @item --listen=@var{host}
  10007. Listen on the network interface for @var{host}. The default is to
  10008. accept connections from any interface.
  10009. @item --user=@var{user}
  10010. @itemx -u @var{user}
  10011. Change privileges to @var{user} as soon as possible---i.e., once the
  10012. server socket is open and the signing key has been read.
  10013. @item --compression[=@var{method}[:@var{level}]]
  10014. @itemx -C [@var{method}[:@var{level}]]
  10015. Compress data using the given @var{method} and @var{level}. @var{method} is
  10016. one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
  10017. omitted, @code{gzip} is used.
  10018. When @var{level} is zero, disable compression. The range 1 to 9 corresponds
  10019. to different compression levels: 1 is the fastest, and 9 is the best
  10020. (CPU-intensive). The default is 3.
  10021. Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
  10022. small increase in CPU usage; see
  10023. @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
  10024. Web page}. However, @code{lzip} achieves low decompression throughput
  10025. (on the order of 50@tie{}MiB/s on modern hardware), which can be a
  10026. bottleneck for someone who downloads over a fast network connection.
  10027. The compression ratio of @code{zstd} is between that of @code{lzip} and
  10028. that of @code{gzip}; its main advantage is a
  10029. @uref{https://facebook.github.io/zstd/,high decompression speed}.
  10030. Unless @option{--cache} is used, compression occurs on the fly and
  10031. the compressed streams are not
  10032. cached. Thus, to reduce load on the machine that runs @command{guix
  10033. publish}, it may be a good idea to choose a low compression level, to
  10034. run @command{guix publish} behind a caching proxy, or to use
  10035. @option{--cache}. Using @option{--cache} has the advantage that it
  10036. allows @command{guix publish} to add @code{Content-Length} HTTP header
  10037. to its responses.
  10038. This option can be repeated, in which case every substitute gets compressed
  10039. using all the selected methods, and all of them are advertised. This is
  10040. useful when users may not support all the compression methods: they can select
  10041. the one they support.
  10042. @item --cache=@var{directory}
  10043. @itemx -c @var{directory}
  10044. Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
  10045. and only serve archives that are in cache.
  10046. When this option is omitted, archives and meta-data are created
  10047. on-the-fly. This can reduce the available bandwidth, especially when
  10048. compression is enabled, since this may become CPU-bound. Another
  10049. drawback of the default mode is that the length of archives is not known
  10050. in advance, so @command{guix publish} does not add a
  10051. @code{Content-Length} HTTP header to its responses, which in turn
  10052. prevents clients from knowing the amount of data being downloaded.
  10053. Conversely, when @option{--cache} is used, the first request for a store
  10054. item (@i{via} a @code{.narinfo} URL) triggers a
  10055. background process to @dfn{bake} the archive---computing its
  10056. @code{.narinfo} and compressing the archive, if needed. Once the
  10057. archive is cached in @var{directory}, subsequent requests succeed and
  10058. are served directly from the cache, which guarantees that clients get
  10059. the best possible bandwidth.
  10060. That first @code{.narinfo} request nonetheless returns 200, provided the
  10061. requested store item is ``small enough'', below the cache bypass
  10062. threshold---see @option{--cache-bypass-threshold} below. That way,
  10063. clients do not have to wait until the archive is baked. For larger
  10064. store items, the first @code{.narinfo} request returns 404, meaning that
  10065. clients have to wait until the archive is baked.
  10066. The ``baking'' process is performed by worker threads. By default, one
  10067. thread per CPU core is created, but this can be customized. See
  10068. @option{--workers} below.
  10069. When @option{--ttl} is used, cached entries are automatically deleted
  10070. when they have expired.
  10071. @item --workers=@var{N}
  10072. When @option{--cache} is used, request the allocation of @var{N} worker
  10073. threads to ``bake'' archives.
  10074. @item --ttl=@var{ttl}
  10075. Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
  10076. (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
  10077. days, @code{1m} means 1 month, and so on.
  10078. This allows the user's Guix to keep substitute information in cache for
  10079. @var{ttl}. However, note that @code{guix publish} does not itself
  10080. guarantee that the store items it provides will indeed remain available
  10081. for as long as @var{ttl}.
  10082. Additionally, when @option{--cache} is used, cached entries that have
  10083. not been accessed for @var{ttl} and that no longer have a corresponding
  10084. item in the store, may be deleted.
  10085. @item --cache-bypass-threshold=@var{size}
  10086. When used in conjunction with @option{--cache}, store items smaller than
  10087. @var{size} are immediately available, even when they are not yet in
  10088. cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
  10089. for megabytes and so on. The default is @code{10M}.
  10090. ``Cache bypass'' allows you to reduce the publication delay for clients
  10091. at the expense of possibly additional I/O and CPU use on the server
  10092. side: depending on the client access patterns, those store items can end
  10093. up being baked several times until a copy is available in cache.
  10094. Increasing the threshold may be useful for sites that have few users, or
  10095. to guarantee that users get substitutes even for store items that are
  10096. not popular.
  10097. @item --nar-path=@var{path}
  10098. Use @var{path} as the prefix for the URLs of ``nar'' files
  10099. (@pxref{Invoking guix archive, normalized archives}).
  10100. By default, nars are served at a URL such as
  10101. @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
  10102. change the @code{/nar} part to @var{path}.
  10103. @item --public-key=@var{file}
  10104. @itemx --private-key=@var{file}
  10105. Use the specific @var{file}s as the public/private key pair used to sign
  10106. the store items being published.
  10107. The files must correspond to the same key pair (the private key is used
  10108. for signing and the public key is merely advertised in the signature
  10109. metadata). They must contain keys in the canonical s-expression format
  10110. as produced by @command{guix archive --generate-key} (@pxref{Invoking
  10111. guix archive}). By default, @file{/etc/guix/signing-key.pub} and
  10112. @file{/etc/guix/signing-key.sec} are used.
  10113. @item --repl[=@var{port}]
  10114. @itemx -r [@var{port}]
  10115. Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
  10116. Reference Manual}) on @var{port} (37146 by default). This is used
  10117. primarily for debugging a running @command{guix publish} server.
  10118. @end table
  10119. Enabling @command{guix publish} on Guix System is a one-liner: just
  10120. instantiate a @code{guix-publish-service-type} service in the @code{services} field
  10121. of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
  10122. @code{guix-publish-service-type}}).
  10123. If you are instead running Guix on a ``foreign distro'', follow these
  10124. instructions:
  10125. @itemize
  10126. @item
  10127. If your host distro uses the systemd init system:
  10128. @example
  10129. # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
  10130. /etc/systemd/system/
  10131. # systemctl start guix-publish && systemctl enable guix-publish
  10132. @end example
  10133. @item
  10134. If your host distro uses the Upstart init system:
  10135. @example
  10136. # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
  10137. # start guix-publish
  10138. @end example
  10139. @item
  10140. Otherwise, proceed similarly with your distro's init system.
  10141. @end itemize
  10142. @node Invoking guix challenge
  10143. @section Invoking @command{guix challenge}
  10144. @cindex reproducible builds
  10145. @cindex verifiable builds
  10146. @cindex @command{guix challenge}
  10147. @cindex challenge
  10148. Do the binaries provided by this server really correspond to the source
  10149. code it claims to build? Is a package build process deterministic?
  10150. These are the questions the @command{guix challenge} command attempts to
  10151. answer.
  10152. The former is obviously an important question: Before using a substitute
  10153. server (@pxref{Substitutes}), one had better @emph{verify} that it
  10154. provides the right binaries, and thus @emph{challenge} it. The latter
  10155. is what enables the former: If package builds are deterministic, then
  10156. independent builds of the package should yield the exact same result,
  10157. bit for bit; if a server provides a binary different from the one
  10158. obtained locally, it may be either corrupt or malicious.
  10159. We know that the hash that shows up in @file{/gnu/store} file names is
  10160. the hash of all the inputs of the process that built the file or
  10161. directory---compilers, libraries, build scripts,
  10162. etc. (@pxref{Introduction}). Assuming deterministic build processes,
  10163. one store file name should map to exactly one build output.
  10164. @command{guix challenge} checks whether there is, indeed, a single
  10165. mapping by comparing the build outputs of several independent builds of
  10166. any given store item.
  10167. The command output looks like this:
  10168. @smallexample
  10169. $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
  10170. updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
  10171. updating list of substitutes from 'https://guix.example.org'... 100.0%
  10172. /gnu/store/@dots{}-openssl-1.0.2d contents differ:
  10173. local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
  10174. https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
  10175. https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
  10176. differing files:
  10177. /lib/libcrypto.so.1.1
  10178. /lib/libssl.so.1.1
  10179. /gnu/store/@dots{}-git-2.5.0 contents differ:
  10180. local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
  10181. https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
  10182. https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
  10183. differing file:
  10184. /libexec/git-core/git-fsck
  10185. /gnu/store/@dots{}-pius-2.1.1 contents differ:
  10186. local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
  10187. https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
  10188. https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
  10189. differing file:
  10190. /share/man/man1/pius.1.gz
  10191. @dots{}
  10192. 6,406 store items were analyzed:
  10193. - 4,749 (74.1%) were identical
  10194. - 525 (8.2%) differed
  10195. - 1,132 (17.7%) were inconclusive
  10196. @end smallexample
  10197. @noindent
  10198. In this example, @command{guix challenge} first scans the store to
  10199. determine the set of locally-built derivations---as opposed to store
  10200. items that were downloaded from a substitute server---and then queries
  10201. all the substitute servers. It then reports those store items for which
  10202. the servers obtained a result different from the local build.
  10203. @cindex non-determinism, in package builds
  10204. As an example, @code{guix.example.org} always gets a different answer.
  10205. Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
  10206. case of Git. This might indicate that the build process of Git is
  10207. non-deterministic, meaning that its output varies as a function of
  10208. various things that Guix does not fully control, in spite of building
  10209. packages in isolated environments (@pxref{Features}). Most common
  10210. sources of non-determinism include the addition of timestamps in build
  10211. results, the inclusion of random numbers, and directory listings sorted
  10212. by inode number. See @uref{https://reproducible-builds.org/docs/}, for
  10213. more information.
  10214. To find out what is wrong with this Git binary, the easiest approach is
  10215. to run:
  10216. @example
  10217. guix challenge git \
  10218. --diff=diffoscope \
  10219. --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
  10220. @end example
  10221. This automatically invokes @command{diffoscope}, which displays detailed
  10222. information about files that differ.
  10223. Alternatively, we can do something along these lines (@pxref{Invoking guix
  10224. archive}):
  10225. @example
  10226. $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
  10227. | lzip -d | guix archive -x /tmp/git
  10228. $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
  10229. @end example
  10230. This command shows the difference between the files resulting from the
  10231. local build, and the files resulting from the build on
  10232. @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
  10233. diffutils, Comparing and Merging Files}). The @command{diff} command
  10234. works great for text files. When binary files differ, a better option
  10235. is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
  10236. visualize differences for all kinds of files.
  10237. Once you have done that work, you can tell whether the differences are due
  10238. to a non-deterministic build process or to a malicious server. We try
  10239. hard to remove sources of non-determinism in packages to make it easier
  10240. to verify substitutes, but of course, this is a process that
  10241. involves not just Guix, but a large part of the free software community.
  10242. In the meantime, @command{guix challenge} is one tool to help address
  10243. the problem.
  10244. If you are writing packages for Guix, you are encouraged to check
  10245. whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
  10246. same build result as you did with:
  10247. @example
  10248. $ guix challenge @var{package}
  10249. @end example
  10250. @noindent
  10251. where @var{package} is a package specification such as
  10252. @code{guile@@2.0} or @code{glibc:debug}.
  10253. The general syntax is:
  10254. @example
  10255. guix challenge @var{options} [@var{packages}@dots{}]
  10256. @end example
  10257. When a difference is found between the hash of a locally-built item and
  10258. that of a server-provided substitute, or among substitutes provided by
  10259. different servers, the command displays it as in the example above and
  10260. its exit code is 2 (other non-zero exit codes denote other kinds of
  10261. errors).
  10262. The one option that matters is:
  10263. @table @code
  10264. @item --substitute-urls=@var{urls}
  10265. Consider @var{urls} the whitespace-separated list of substitute source
  10266. URLs to compare to.
  10267. @item --diff=@var{mode}
  10268. Upon mismatches, show differences according to @var{mode}, one of:
  10269. @table @asis
  10270. @item @code{simple} (the default)
  10271. Show the list of files that differ.
  10272. @item @code{diffoscope}
  10273. @itemx @var{command}
  10274. Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
  10275. two directories whose contents do not match.
  10276. When @var{command} is an absolute file name, run @var{command} instead
  10277. of Diffoscope.
  10278. @item @code{none}
  10279. Do not show further details about the differences.
  10280. @end table
  10281. Thus, unless @option{--diff=none} is passed, @command{guix challenge}
  10282. downloads the store items from the given substitute servers so that it
  10283. can compare them.
  10284. @item --verbose
  10285. @itemx -v
  10286. Show details about matches (identical contents) in addition to
  10287. information about mismatches.
  10288. @end table
  10289. @node Invoking guix copy
  10290. @section Invoking @command{guix copy}
  10291. @cindex copy, of store items, over SSH
  10292. @cindex SSH, copy of store items
  10293. @cindex sharing store items across machines
  10294. @cindex transferring store items across machines
  10295. The @command{guix copy} command copies items from the store of one
  10296. machine to that of another machine over a secure shell (SSH)
  10297. connection@footnote{This command is available only when Guile-SSH was
  10298. found. @xref{Requirements}, for details.}. For example, the following
  10299. command copies the @code{coreutils} package, the user's profile, and all
  10300. their dependencies over to @var{host}, logged in as @var{user}:
  10301. @example
  10302. guix copy --to=@var{user}@@@var{host} \
  10303. coreutils `readlink -f ~/.guix-profile`
  10304. @end example
  10305. If some of the items to be copied are already present on @var{host},
  10306. they are not actually sent.
  10307. The command below retrieves @code{libreoffice} and @code{gimp} from
  10308. @var{host}, assuming they are available there:
  10309. @example
  10310. guix copy --from=@var{host} libreoffice gimp
  10311. @end example
  10312. The SSH connection is established using the Guile-SSH client, which is
  10313. compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
  10314. @file{~/.ssh/config}, and uses the SSH agent for authentication.
  10315. The key used to sign items that are sent must be accepted by the remote
  10316. machine. Likewise, the key used by the remote machine to sign items you
  10317. are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
  10318. own daemon. @xref{Invoking guix archive}, for more information about
  10319. store item authentication.
  10320. The general syntax is:
  10321. @example
  10322. guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
  10323. @end example
  10324. You must always specify one of the following options:
  10325. @table @code
  10326. @item --to=@var{spec}
  10327. @itemx --from=@var{spec}
  10328. Specify the host to send to or receive from. @var{spec} must be an SSH
  10329. spec such as @code{example.org}, @code{charlie@@example.org}, or
  10330. @code{charlie@@example.org:2222}.
  10331. @end table
  10332. The @var{items} can be either package names, such as @code{gimp}, or
  10333. store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
  10334. When specifying the name of a package to send, it is first built if
  10335. needed, unless @option{--dry-run} was specified. Common build options
  10336. are supported (@pxref{Common Build Options}).
  10337. @node Invoking guix container
  10338. @section Invoking @command{guix container}
  10339. @cindex container
  10340. @cindex @command{guix container}
  10341. @quotation Note
  10342. As of version @value{VERSION}, this tool is experimental. The interface
  10343. is subject to radical change in the future.
  10344. @end quotation
  10345. The purpose of @command{guix container} is to manipulate processes
  10346. running within an isolated environment, commonly known as a
  10347. ``container'', typically created by the @command{guix environment}
  10348. (@pxref{Invoking guix environment}) and @command{guix system container}
  10349. (@pxref{Invoking guix system}) commands.
  10350. The general syntax is:
  10351. @example
  10352. guix container @var{action} @var{options}@dots{}
  10353. @end example
  10354. @var{action} specifies the operation to perform with a container, and
  10355. @var{options} specifies the context-specific arguments for the action.
  10356. The following actions are available:
  10357. @table @code
  10358. @item exec
  10359. Execute a command within the context of a running container.
  10360. The syntax is:
  10361. @example
  10362. guix container exec @var{pid} @var{program} @var{arguments}@dots{}
  10363. @end example
  10364. @var{pid} specifies the process ID of the running container.
  10365. @var{program} specifies an executable file name within the root file
  10366. system of the container. @var{arguments} are the additional options that
  10367. will be passed to @var{program}.
  10368. The following command launches an interactive login shell inside a
  10369. Guix system container, started by @command{guix system container}, and whose
  10370. process ID is 9001:
  10371. @example
  10372. guix container exec 9001 /run/current-system/profile/bin/bash --login
  10373. @end example
  10374. Note that the @var{pid} cannot be the parent process of a container. It
  10375. must be PID 1 of the container or one of its child processes.
  10376. @end table
  10377. @node Invoking guix weather
  10378. @section Invoking @command{guix weather}
  10379. Occasionally you're grumpy because substitutes are lacking and you end
  10380. up building packages by yourself (@pxref{Substitutes}). The
  10381. @command{guix weather} command reports on substitute availability on the
  10382. specified servers so you can have an idea of whether you'll be grumpy
  10383. today. It can sometimes be useful info as a user, but it is primarily
  10384. useful to people running @command{guix publish} (@pxref{Invoking guix
  10385. publish}).
  10386. @cindex statistics, for substitutes
  10387. @cindex availability of substitutes
  10388. @cindex substitute availability
  10389. @cindex weather, substitute availability
  10390. Here's a sample run:
  10391. @example
  10392. $ guix weather --substitute-urls=https://guix.example.org
  10393. computing 5,872 package derivations for x86_64-linux...
  10394. looking for 6,128 store items on https://guix.example.org..
  10395. updating list of substitutes from 'https://guix.example.org'... 100.0%
  10396. https://guix.example.org
  10397. 43.4% substitutes available (2,658 out of 6,128)
  10398. 7,032.5 MiB of nars (compressed)
  10399. 19,824.2 MiB on disk (uncompressed)
  10400. 0.030 seconds per request (182.9 seconds in total)
  10401. 33.5 requests per second
  10402. 9.8% (342 out of 3,470) of the missing items are queued
  10403. 867 queued builds
  10404. x86_64-linux: 518 (59.7%)
  10405. i686-linux: 221 (25.5%)
  10406. aarch64-linux: 128 (14.8%)
  10407. build rate: 23.41 builds per hour
  10408. x86_64-linux: 11.16 builds per hour
  10409. i686-linux: 6.03 builds per hour
  10410. aarch64-linux: 6.41 builds per hour
  10411. @end example
  10412. @cindex continuous integration, statistics
  10413. As you can see, it reports the fraction of all the packages for which
  10414. substitutes are available on the server---regardless of whether
  10415. substitutes are enabled, and regardless of whether this server's signing
  10416. key is authorized. It also reports the size of the compressed archives
  10417. (``nars'') provided by the server, the size the corresponding store
  10418. items occupy in the store (assuming deduplication is turned off), and
  10419. the server's throughput. The second part gives continuous integration
  10420. (CI) statistics, if the server supports it. In addition, using the
  10421. @option{--coverage} option, @command{guix weather} can list ``important''
  10422. package substitutes missing on the server (see below).
  10423. To achieve that, @command{guix weather} queries over HTTP(S) meta-data
  10424. (@dfn{narinfos}) for all the relevant store items. Like @command{guix
  10425. challenge}, it ignores signatures on those substitutes, which is
  10426. innocuous since the command only gathers statistics and cannot install
  10427. those substitutes.
  10428. The general syntax is:
  10429. @example
  10430. guix weather @var{options}@dots{} [@var{packages}@dots{}]
  10431. @end example
  10432. When @var{packages} is omitted, @command{guix weather} checks the availability
  10433. of substitutes for @emph{all} the packages, or for those specified with
  10434. @option{--manifest}; otherwise it only considers the specified packages. It
  10435. is also possible to query specific system types with @option{--system}.
  10436. @command{guix weather} exits with a non-zero code when the fraction of
  10437. available substitutes is below 100%.
  10438. The available options are listed below.
  10439. @table @code
  10440. @item --substitute-urls=@var{urls}
  10441. @var{urls} is the space-separated list of substitute server URLs to
  10442. query. When this option is omitted, the default set of substitute
  10443. servers is queried.
  10444. @item --system=@var{system}
  10445. @itemx -s @var{system}
  10446. Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
  10447. option can be repeated, in which case @command{guix weather} will query
  10448. substitutes for several system types.
  10449. @item --manifest=@var{file}
  10450. Instead of querying substitutes for all the packages, only ask for those
  10451. specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
  10452. with the @code{-m} option of @command{guix package} (@pxref{Invoking
  10453. guix package}).
  10454. This option can be repeated several times, in which case the manifests
  10455. are concatenated.
  10456. @item --coverage[=@var{count}]
  10457. @itemx -c [@var{count}]
  10458. Report on substitute coverage for packages: list packages with at least
  10459. @var{count} dependents (zero by default) for which substitutes are
  10460. unavailable. Dependent packages themselves are not listed: if @var{b} depends
  10461. on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
  10462. @var{b} usually lacks substitutes as well. The result looks like this:
  10463. @example
  10464. $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
  10465. computing 8,983 package derivations for x86_64-linux...
  10466. looking for 9,343 store items on @value{SUBSTITUTE-URL}...
  10467. updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
  10468. @value{SUBSTITUTE-URL}
  10469. 64.7% substitutes available (6,047 out of 9,343)
  10470. @dots{}
  10471. 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
  10472. 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
  10473. 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
  10474. 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
  10475. @dots{}
  10476. @end example
  10477. What this example shows is that @code{kcoreaddons} and presumably the 58
  10478. packages that depend on it have no substitutes at
  10479. @code{@value{SUBSTITUTE-SERVER}}; likewise for @code{qgpgme} and the 46
  10480. packages that depend on it.
  10481. If you are a Guix developer, or if you are taking care of this build farm,
  10482. you'll probably want to have a closer look at these packages: they may simply
  10483. fail to build.
  10484. @item --display-missing
  10485. Display the list of store items for which substitutes are missing.
  10486. @end table
  10487. @node Invoking guix processes
  10488. @section Invoking @command{guix processes}
  10489. The @command{guix processes} command can be useful to developers and system
  10490. administrators, especially on multi-user machines and on build farms: it lists
  10491. the current sessions (connections to the daemon), as well as information about
  10492. the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
  10493. started with @option{--listen} specifying a TCP endpoint, are @emph{not}
  10494. listed.}. Here's an example of the information it returns:
  10495. @example
  10496. $ sudo guix processes
  10497. SessionPID: 19002
  10498. ClientPID: 19090
  10499. ClientCommand: guix environment --ad-hoc python
  10500. SessionPID: 19402
  10501. ClientPID: 19367
  10502. ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
  10503. SessionPID: 19444
  10504. ClientPID: 19419
  10505. ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
  10506. LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
  10507. LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
  10508. LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
  10509. ChildPID: 20495
  10510. ChildCommand: guix offload x86_64-linux 7200 1 28800
  10511. ChildPID: 27733
  10512. ChildCommand: guix offload x86_64-linux 7200 1 28800
  10513. ChildPID: 27793
  10514. ChildCommand: guix offload x86_64-linux 7200 1 28800
  10515. @end example
  10516. In this example we see that @command{guix-daemon} has three clients:
  10517. @command{guix environment}, @command{guix publish}, and the Cuirass continuous
  10518. integration tool; their process identifier (PID) is given by the
  10519. @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
  10520. @command{guix-daemon} sub-process of this particular session.
  10521. The @code{LockHeld} fields show which store items are currently locked
  10522. by this session, which corresponds to store items being built or
  10523. substituted (the @code{LockHeld} field is not displayed when
  10524. @command{guix processes} is not running as root). Last, by looking at
  10525. the @code{ChildPID} and @code{ChildCommand} fields, we understand that
  10526. these three builds are being offloaded (@pxref{Daemon Offload Setup}).
  10527. The output is in Recutils format so we can use the handy @command{recsel}
  10528. command to select sessions of interest (@pxref{Selection Expressions,,,
  10529. recutils, GNU recutils manual}). As an example, the command shows the command
  10530. line and PID of the client that triggered the build of a Perl package:
  10531. @example
  10532. $ sudo guix processes | \
  10533. recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
  10534. ClientPID: 19419
  10535. ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
  10536. @end example
  10537. Additional options are listed below.
  10538. @table @code
  10539. @item --format=@var{format}
  10540. @itemx -f @var{format}
  10541. Produce output in the specified @var{format}, one of:
  10542. @table @code
  10543. @item recutils
  10544. The default option. It outputs a set of Session recutils records
  10545. that include each @code{ChildProcess} as a field.
  10546. @item normalized
  10547. Normalize the output records into record sets (@pxref{Record Sets,,,
  10548. recutils, GNU recutils manual}). Normalizing into record sets allows
  10549. joins across record types. The example below lists the PID of each
  10550. @code{ChildProcess} and the associated PID for @code{Session} that
  10551. spawned the @code{ChildProcess} where the @code{Session} was started
  10552. using @command{guix build}.
  10553. @example
  10554. $ guix processes --format=normalized | \
  10555. recsel \
  10556. -j Session \
  10557. -t ChildProcess \
  10558. -p Session.PID,PID \
  10559. -e 'Session.ClientCommand ~ "guix build"'
  10560. PID: 4435
  10561. Session_PID: 4278
  10562. PID: 4554
  10563. Session_PID: 4278
  10564. PID: 4646
  10565. Session_PID: 4278
  10566. @end example
  10567. @end table
  10568. @end table
  10569. @node System Configuration
  10570. @chapter System Configuration
  10571. @cindex system configuration
  10572. Guix System supports a consistent whole-system configuration
  10573. mechanism. By that we mean that all aspects of the global system
  10574. configuration---such as the available system services, timezone and
  10575. locale settings, user accounts---are declared in a single place. Such
  10576. a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
  10577. One of the advantages of putting all the system configuration under the
  10578. control of Guix is that it supports transactional system upgrades, and
  10579. makes it possible to roll back to a previous system instantiation,
  10580. should something go wrong with the new one (@pxref{Features}). Another
  10581. advantage is that it makes it easy to replicate the exact same configuration
  10582. across different machines, or at different points in time, without
  10583. having to resort to additional administration tools layered on top of
  10584. the own tools of the system.
  10585. @c Yes, we're talking of Puppet, Chef, & co. here. ↑
  10586. This section describes this mechanism. First we focus on the system
  10587. administrator's viewpoint---explaining how the system is configured and
  10588. instantiated. Then we show how this mechanism can be extended, for
  10589. instance to support new system services.
  10590. @menu
  10591. * Using the Configuration System:: Customizing your GNU system.
  10592. * operating-system Reference:: Detail of operating-system declarations.
  10593. * File Systems:: Configuring file system mounts.
  10594. * Mapped Devices:: Block device extra processing.
  10595. * User Accounts:: Specifying user accounts.
  10596. * Keyboard Layout:: How the system interprets key strokes.
  10597. * Locales:: Language and cultural convention settings.
  10598. * Services:: Specifying system services.
  10599. * Setuid Programs:: Programs running with root privileges.
  10600. * X.509 Certificates:: Authenticating HTTPS servers.
  10601. * Name Service Switch:: Configuring libc's name service switch.
  10602. * Initial RAM Disk:: Linux-Libre bootstrapping.
  10603. * Bootloader Configuration:: Configuring the boot loader.
  10604. * Invoking guix system:: Instantiating a system configuration.
  10605. * Invoking guix deploy:: Deploying a system configuration to a remote host.
  10606. * Running Guix in a VM:: How to run Guix System in a virtual machine.
  10607. * Defining Services:: Adding new service definitions.
  10608. @end menu
  10609. @node Using the Configuration System
  10610. @section Using the Configuration System
  10611. The operating system is configured by providing an
  10612. @code{operating-system} declaration in a file that can then be passed to
  10613. the @command{guix system} command (@pxref{Invoking guix system}). A
  10614. simple setup, with the default system services, the default Linux-Libre
  10615. kernel, initial RAM disk, and boot loader looks like this:
  10616. @findex operating-system
  10617. @lisp
  10618. @include os-config-bare-bones.texi
  10619. @end lisp
  10620. This example should be self-describing. Some of the fields defined
  10621. above, such as @code{host-name} and @code{bootloader}, are mandatory.
  10622. Others, such as @code{packages} and @code{services}, can be omitted, in
  10623. which case they get a default value.
  10624. Below we discuss the effect of some of the most important fields
  10625. (@pxref{operating-system Reference}, for details about all the available
  10626. fields), and how to @dfn{instantiate} the operating system using
  10627. @command{guix system}.
  10628. @unnumberedsubsec Bootloader
  10629. @cindex legacy boot, on Intel machines
  10630. @cindex BIOS boot, on Intel machines
  10631. @cindex UEFI boot
  10632. @cindex EFI boot
  10633. The @code{bootloader} field describes the method that will be used to boot
  10634. your system. Machines based on Intel processors can boot in ``legacy'' BIOS
  10635. mode, as in the example above. However, more recent machines rely instead on
  10636. the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
  10637. the @code{bootloader} field should contain something along these lines:
  10638. @lisp
  10639. (bootloader-configuration
  10640. (bootloader grub-efi-bootloader)
  10641. (target "/boot/efi"))
  10642. @end lisp
  10643. @xref{Bootloader Configuration}, for more information on the available
  10644. configuration options.
  10645. @unnumberedsubsec Globally-Visible Packages
  10646. @vindex %base-packages
  10647. The @code{packages} field lists packages that will be globally visible
  10648. on the system, for all user accounts---i.e., in every user's @env{PATH}
  10649. environment variable---in addition to the per-user profiles
  10650. (@pxref{Invoking guix package}). The @code{%base-packages} variable
  10651. provides all the tools one would expect for basic user and administrator
  10652. tasks---including the GNU Core Utilities, the GNU Networking Utilities,
  10653. the GNU Zile lightweight text editor, @command{find}, @command{grep},
  10654. etc. The example above adds GNU@tie{}Screen to those,
  10655. taken from the @code{(gnu packages screen)}
  10656. module (@pxref{Package Modules}). The
  10657. @code{(list package output)} syntax can be used to add a specific output
  10658. of a package:
  10659. @lisp
  10660. (use-modules (gnu packages))
  10661. (use-modules (gnu packages dns))
  10662. (operating-system
  10663. ;; ...
  10664. (packages (cons (list bind "utils")
  10665. %base-packages)))
  10666. @end lisp
  10667. @findex specification->package
  10668. Referring to packages by variable name, like @code{bind} above, has
  10669. the advantage of being unambiguous; it also allows typos and such to be
  10670. diagnosed right away as ``unbound variables''. The downside is that one
  10671. needs to know which module defines which package, and to augment the
  10672. @code{use-package-modules} line accordingly. To avoid that, one can use
  10673. the @code{specification->package} procedure of the @code{(gnu packages)}
  10674. module, which returns the best package for a given name or name and
  10675. version:
  10676. @lisp
  10677. (use-modules (gnu packages))
  10678. (operating-system
  10679. ;; ...
  10680. (packages (append (map specification->package
  10681. '("tcpdump" "htop" "gnupg@@2.0"))
  10682. %base-packages)))
  10683. @end lisp
  10684. @unnumberedsubsec System Services
  10685. @cindex services
  10686. @vindex %base-services
  10687. The @code{services} field lists @dfn{system services} to be made
  10688. available when the system starts (@pxref{Services}).
  10689. The @code{operating-system} declaration above specifies that, in
  10690. addition to the basic services, we want the OpenSSH secure shell
  10691. daemon listening on port 2222 (@pxref{Networking Services,
  10692. @code{openssh-service-type}}). Under the hood,
  10693. @code{openssh-service-type} arranges so that @command{sshd} is started with the
  10694. right command-line options, possibly with supporting configuration files
  10695. generated as needed (@pxref{Defining Services}).
  10696. @cindex customization, of services
  10697. @findex modify-services
  10698. Occasionally, instead of using the base services as is, you will want to
  10699. customize them. To do this, use @code{modify-services} (@pxref{Service
  10700. Reference, @code{modify-services}}) to modify the list.
  10701. For example, suppose you want to modify @code{guix-daemon} and Mingetty
  10702. (the console log-in) in the @code{%base-services} list (@pxref{Base
  10703. Services, @code{%base-services}}). To do that, you can write the
  10704. following in your operating system declaration:
  10705. @lisp
  10706. (define %my-services
  10707. ;; My very own list of services.
  10708. (modify-services %base-services
  10709. (guix-service-type config =>
  10710. (guix-configuration
  10711. (inherit config)
  10712. ;; Fetch substitutes from example.org.
  10713. (substitute-urls
  10714. (list "https://example.org/guix"
  10715. "https://ci.guix.gnu.org"))))
  10716. (mingetty-service-type config =>
  10717. (mingetty-configuration
  10718. (inherit config)
  10719. ;; Automatially log in as "guest".
  10720. (auto-login "guest")))))
  10721. (operating-system
  10722. ;; @dots{}
  10723. (services %my-services))
  10724. @end lisp
  10725. This changes the configuration---i.e., the service parameters---of the
  10726. @code{guix-service-type} instance, and that of all the
  10727. @code{mingetty-service-type} instances in the @code{%base-services} list.
  10728. Observe how this is accomplished: first, we arrange for the original
  10729. configuration to be bound to the identifier @code{config} in the
  10730. @var{body}, and then we write the @var{body} so that it evaluates to the
  10731. desired configuration. In particular, notice how we use @code{inherit}
  10732. to create a new configuration which has the same values as the old
  10733. configuration, but with a few modifications.
  10734. @cindex encrypted disk
  10735. The configuration for a typical ``desktop'' usage, with an encrypted
  10736. root partition, the X11 display
  10737. server, GNOME and Xfce (users can choose which of these desktop
  10738. environments to use at the log-in screen by pressing @kbd{F1}), network
  10739. management, power management, and more, would look like this:
  10740. @lisp
  10741. @include os-config-desktop.texi
  10742. @end lisp
  10743. A graphical system with a choice of lightweight window managers
  10744. instead of full-blown desktop environments would look like this:
  10745. @lisp
  10746. @include os-config-lightweight-desktop.texi
  10747. @end lisp
  10748. This example refers to the @file{/boot/efi} file system by its UUID,
  10749. @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
  10750. as returned by the @command{blkid} command.
  10751. @xref{Desktop Services}, for the exact list of services provided by
  10752. @code{%desktop-services}. @xref{X.509 Certificates}, for background
  10753. information about the @code{nss-certs} package that is used here.
  10754. Again, @code{%desktop-services} is just a list of service objects. If
  10755. you want to remove services from there, you can do so using the
  10756. procedures for list filtering (@pxref{SRFI-1 Filtering and
  10757. Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
  10758. following expression returns a list that contains all the services in
  10759. @code{%desktop-services} minus the Avahi service:
  10760. @lisp
  10761. (remove (lambda (service)
  10762. (eq? (service-kind service) avahi-service-type))
  10763. %desktop-services)
  10764. @end lisp
  10765. @unnumberedsubsec Instantiating the System
  10766. Assuming the @code{operating-system} declaration
  10767. is stored in the @file{my-system-config.scm}
  10768. file, the @command{guix system reconfigure my-system-config.scm} command
  10769. instantiates that configuration, and makes it the default GRUB boot
  10770. entry (@pxref{Invoking guix system}).
  10771. The normal way to change the system configuration is by updating this
  10772. file and re-running @command{guix system reconfigure}. One should never
  10773. have to touch files in @file{/etc} or to run commands that modify the
  10774. system state such as @command{useradd} or @command{grub-install}. In
  10775. fact, you must avoid that since that would not only void your warranty
  10776. but also prevent you from rolling back to previous versions of your
  10777. system, should you ever need to.
  10778. @cindex roll-back, of the operating system
  10779. Speaking of roll-back, each time you run @command{guix system
  10780. reconfigure}, a new @dfn{generation} of the system is created---without
  10781. modifying or deleting previous generations. Old system generations get
  10782. an entry in the bootloader boot menu, allowing you to boot them in case
  10783. something went wrong with the latest generation. Reassuring, no? The
  10784. @command{guix system list-generations} command lists the system
  10785. generations available on disk. It is also possible to roll back the
  10786. system via the commands @command{guix system roll-back} and
  10787. @command{guix system switch-generation}.
  10788. Although the @command{guix system reconfigure} command will not modify
  10789. previous generations, you must take care when the current generation is not
  10790. the latest (e.g., after invoking @command{guix system roll-back}), since
  10791. the operation might overwrite a later generation (@pxref{Invoking guix
  10792. system}).
  10793. @unnumberedsubsec The Programming Interface
  10794. At the Scheme level, the bulk of an @code{operating-system} declaration
  10795. is instantiated with the following monadic procedure (@pxref{The Store
  10796. Monad}):
  10797. @deffn {Monadic Procedure} operating-system-derivation os
  10798. Return a derivation that builds @var{os}, an @code{operating-system}
  10799. object (@pxref{Derivations}).
  10800. The output of the derivation is a single directory that refers to all
  10801. the packages, configuration files, and other supporting files needed to
  10802. instantiate @var{os}.
  10803. @end deffn
  10804. This procedure is provided by the @code{(gnu system)} module. Along
  10805. with @code{(gnu services)} (@pxref{Services}), this module contains the
  10806. guts of Guix System. Make sure to visit it!
  10807. @node operating-system Reference
  10808. @section @code{operating-system} Reference
  10809. This section summarizes all the options available in
  10810. @code{operating-system} declarations (@pxref{Using the Configuration
  10811. System}).
  10812. @deftp {Data Type} operating-system
  10813. This is the data type representing an operating system configuration.
  10814. By that, we mean all the global system configuration, not per-user
  10815. configuration (@pxref{Using the Configuration System}).
  10816. @table @asis
  10817. @item @code{kernel} (default: @code{linux-libre})
  10818. The package object of the operating system kernel to
  10819. use@footnote{Currently only the Linux-libre kernel is fully supported.
  10820. Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
  10821. available when building a virtual machine disk image.}.
  10822. @cindex hurd
  10823. @item @code{hurd} (default: @code{#f})
  10824. The package object of the Hurd to be started by the kernel. When this
  10825. field is set, produce a GNU/Hurd operating system. In that case,
  10826. @code{kernel} must also be set to the @code{gnumach} package---the
  10827. microkernel the Hurd runs on.
  10828. @quotation Warning
  10829. This feature is experimental and only supported for disk images.
  10830. @end quotation
  10831. @item @code{kernel-loadable-modules} (default: '())
  10832. A list of objects (usually packages) to collect loadable kernel modules
  10833. from--e.g. @code{(list ddcci-driver-linux)}.
  10834. @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
  10835. List of strings or gexps representing additional arguments to pass on
  10836. the command-line of the kernel---e.g., @code{("console=ttyS0")}.
  10837. @item @code{bootloader}
  10838. The system bootloader configuration object. @xref{Bootloader Configuration}.
  10839. @item @code{label}
  10840. This is the label (a string) as it appears in the bootloader's menu entry.
  10841. The default label includes the kernel name and version.
  10842. @item @code{keyboard-layout} (default: @code{#f})
  10843. This field specifies the keyboard layout to use in the console. It can be
  10844. either @code{#f}, in which case the default keyboard layout is used (usually
  10845. US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
  10846. for more information.
  10847. This keyboard layout is in effect as soon as the kernel has booted. For
  10848. instance, it is the keyboard layout in effect when you type a passphrase if
  10849. your root file system is on a @code{luks-device-mapping} mapped device
  10850. (@pxref{Mapped Devices}).
  10851. @quotation Note
  10852. This does @emph{not} specify the keyboard layout used by the bootloader, nor
  10853. that used by the graphical display server. @xref{Bootloader Configuration},
  10854. for information on how to specify the bootloader's keyboard layout. @xref{X
  10855. Window}, for information on how to specify the keyboard layout used by the X
  10856. Window System.
  10857. @end quotation
  10858. @item @code{initrd-modules} (default: @code{%base-initrd-modules})
  10859. @cindex initrd
  10860. @cindex initial RAM disk
  10861. The list of Linux kernel modules that need to be available in the
  10862. initial RAM disk. @xref{Initial RAM Disk}.
  10863. @item @code{initrd} (default: @code{base-initrd})
  10864. A procedure that returns an initial RAM disk for the Linux
  10865. kernel. This field is provided to support low-level customization and
  10866. should rarely be needed for casual use. @xref{Initial RAM Disk}.
  10867. @item @code{firmware} (default: @code{%base-firmware})
  10868. @cindex firmware
  10869. List of firmware packages loadable by the operating system kernel.
  10870. The default includes firmware needed for Atheros- and Broadcom-based
  10871. WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
  10872. respectively). @xref{Hardware Considerations}, for more info on
  10873. supported hardware.
  10874. @item @code{host-name}
  10875. The host name.
  10876. @item @code{hosts-file}
  10877. @cindex hosts file
  10878. A file-like object (@pxref{G-Expressions, file-like objects}) for use as
  10879. @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
  10880. Reference Manual}). The default is a file with entries for
  10881. @code{localhost} and @var{host-name}.
  10882. @item @code{mapped-devices} (default: @code{'()})
  10883. A list of mapped devices. @xref{Mapped Devices}.
  10884. @item @code{file-systems}
  10885. A list of file systems. @xref{File Systems}.
  10886. @cindex swap devices
  10887. @cindex swap space
  10888. @item @code{swap-devices} (default: @code{'()})
  10889. A list of UUIDs, file system labels, or strings identifying devices or
  10890. files to be used for ``swap
  10891. space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
  10892. Manual}). Here are some examples:
  10893. @table @code
  10894. @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
  10895. Use the swap partition with the given UUID@. You can learn the UUID of a
  10896. Linux swap partition by running @command{swaplabel @var{device}}, where
  10897. @var{device} is the @file{/dev} file name of that partition.
  10898. @item (list (file-system-label "swap"))
  10899. Use the partition with label @code{swap}. Again, the
  10900. @command{swaplabel} command allows you to view and change the label of a
  10901. Linux swap partition.
  10902. @item (list "/swapfile")
  10903. Use the file @file{/swapfile} as swap space.
  10904. @item (list "/dev/sda3" "/dev/sdb2")
  10905. Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
  10906. We recommend referring to swap devices by UUIDs or labels as shown above
  10907. instead.
  10908. @end table
  10909. It is possible to specify a swap file in a file system on a mapped
  10910. device (under @file{/dev/mapper}), provided that the necessary device
  10911. mapping and file system are also specified. @xref{Mapped Devices} and
  10912. @ref{File Systems}.
  10913. @item @code{users} (default: @code{%base-user-accounts})
  10914. @itemx @code{groups} (default: @code{%base-groups})
  10915. List of user accounts and groups. @xref{User Accounts}.
  10916. If the @code{users} list lacks a user account with UID@tie{}0, a
  10917. ``root'' account with UID@tie{}0 is automatically added.
  10918. @item @code{skeletons} (default: @code{(default-skeletons)})
  10919. A list of target file name/file-like object tuples (@pxref{G-Expressions,
  10920. file-like objects}). These are the skeleton files that will be added to
  10921. the home directory of newly-created user accounts.
  10922. For instance, a valid value may look like this:
  10923. @lisp
  10924. `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
  10925. (".guile" ,(plain-file "guile"
  10926. "(use-modules (ice-9 readline))
  10927. (activate-readline)")))
  10928. @end lisp
  10929. @item @code{issue} (default: @code{%default-issue})
  10930. A string denoting the contents of the @file{/etc/issue} file, which is
  10931. displayed when users log in on a text console.
  10932. @item @code{packages} (default: @code{%base-packages})
  10933. A list of packages to be installed in the global profile, which is accessible
  10934. at @file{/run/current-system/profile}. Each element is either a package
  10935. variable or a package/output tuple. Here's a simple example of both:
  10936. @lisp
  10937. (cons* git ; the default "out" output
  10938. (list git "send-email") ; another output of git
  10939. %base-packages) ; the default set
  10940. @end lisp
  10941. The default set includes core utilities and it is good practice to
  10942. install non-core utilities in user profiles (@pxref{Invoking guix
  10943. package}).
  10944. @item @code{timezone}
  10945. A timezone identifying string---e.g., @code{"Europe/Paris"}.
  10946. You can run the @command{tzselect} command to find out which timezone
  10947. string corresponds to your region. Choosing an invalid timezone name
  10948. causes @command{guix system} to fail.
  10949. @item @code{locale} (default: @code{"en_US.utf8"})
  10950. The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
  10951. Library Reference Manual}). @xref{Locales}, for more information.
  10952. @item @code{locale-definitions} (default: @code{%default-locale-definitions})
  10953. The list of locale definitions to be compiled and that may be used at
  10954. run time. @xref{Locales}.
  10955. @item @code{locale-libcs} (default: @code{(list @var{glibc})})
  10956. The list of GNU@tie{}libc packages whose locale data and tools are used
  10957. to build the locale definitions. @xref{Locales}, for compatibility
  10958. considerations that justify this option.
  10959. @item @code{name-service-switch} (default: @code{%default-nss})
  10960. Configuration of the libc name service switch (NSS)---a
  10961. @code{<name-service-switch>} object. @xref{Name Service Switch}, for
  10962. details.
  10963. @item @code{services} (default: @code{%base-services})
  10964. A list of service objects denoting system services. @xref{Services}.
  10965. @cindex essential services
  10966. @item @code{essential-services} (default: ...)
  10967. The list of ``essential services''---i.e., things like instances of
  10968. @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
  10969. Reference}), which are derived from the operating system definition itself.
  10970. As a user you should @emph{never} need to touch this field.
  10971. @item @code{pam-services} (default: @code{(base-pam-services)})
  10972. @cindex PAM
  10973. @cindex pluggable authentication modules
  10974. Linux @dfn{pluggable authentication module} (PAM) services.
  10975. @c FIXME: Add xref to PAM services section.
  10976. @item @code{setuid-programs} (default: @code{%setuid-programs})
  10977. List of string-valued G-expressions denoting setuid programs.
  10978. @xref{Setuid Programs}.
  10979. @item @code{sudoers-file} (default: @code{%sudoers-specification})
  10980. @cindex sudoers file
  10981. The contents of the @file{/etc/sudoers} file as a file-like object
  10982. (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
  10983. This file specifies which users can use the @command{sudo} command, what
  10984. they are allowed to do, and what privileges they may gain. The default
  10985. is that only @code{root} and members of the @code{wheel} group may use
  10986. @code{sudo}.
  10987. @end table
  10988. @deffn {Scheme Syntax} this-operating-system
  10989. When used in the @emph{lexical scope} of an operating system field definition,
  10990. this identifier resolves to the operating system being defined.
  10991. The example below shows how to refer to the operating system being defined in
  10992. the definition of the @code{label} field:
  10993. @lisp
  10994. (use-modules (gnu) (guix))
  10995. (operating-system
  10996. ;; ...
  10997. (label (package-full-name
  10998. (operating-system-kernel this-operating-system))))
  10999. @end lisp
  11000. It is an error to refer to @code{this-operating-system} outside an operating
  11001. system definition.
  11002. @end deffn
  11003. @end deftp
  11004. @node File Systems
  11005. @section File Systems
  11006. The list of file systems to be mounted is specified in the
  11007. @code{file-systems} field of the operating system declaration
  11008. (@pxref{Using the Configuration System}). Each file system is declared
  11009. using the @code{file-system} form, like this:
  11010. @lisp
  11011. (file-system
  11012. (mount-point "/home")
  11013. (device "/dev/sda3")
  11014. (type "ext4"))
  11015. @end lisp
  11016. As usual, some of the fields are mandatory---those shown in the example
  11017. above---while others can be omitted. These are described below.
  11018. @deftp {Data Type} file-system
  11019. Objects of this type represent file systems to be mounted. They
  11020. contain the following members:
  11021. @table @asis
  11022. @item @code{type}
  11023. This is a string specifying the type of the file system---e.g.,
  11024. @code{"ext4"}.
  11025. @item @code{mount-point}
  11026. This designates the place where the file system is to be mounted.
  11027. @item @code{device}
  11028. This names the ``source'' of the file system. It can be one of three
  11029. things: a file system label, a file system UUID, or the name of a
  11030. @file{/dev} node. Labels and UUIDs offer a way to refer to file
  11031. systems without having to hard-code their actual device
  11032. name@footnote{Note that, while it is tempting to use
  11033. @file{/dev/disk/by-uuid} and similar device names to achieve the same
  11034. result, this is not recommended: These special device nodes are created
  11035. by the udev daemon and may be unavailable at the time the device is
  11036. mounted.}.
  11037. @findex file-system-label
  11038. File system labels are created using the @code{file-system-label}
  11039. procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
  11040. plain strings. Here's an example of a file system referred to by its
  11041. label, as shown by the @command{e2label} command:
  11042. @lisp
  11043. (file-system
  11044. (mount-point "/home")
  11045. (type "ext4")
  11046. (device (file-system-label "my-home")))
  11047. @end lisp
  11048. @findex uuid
  11049. UUIDs are converted from their string representation (as shown by the
  11050. @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
  11051. @code{uuid} form expects 16-byte UUIDs as defined in
  11052. @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
  11053. form of UUID used by the ext2 family of file systems and others, but it
  11054. is different from ``UUIDs'' found in FAT file systems, for instance.},
  11055. like this:
  11056. @lisp
  11057. (file-system
  11058. (mount-point "/home")
  11059. (type "ext4")
  11060. (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
  11061. @end lisp
  11062. When the source of a file system is a mapped device (@pxref{Mapped
  11063. Devices}), its @code{device} field @emph{must} refer to the mapped
  11064. device name---e.g., @file{"/dev/mapper/root-partition"}.
  11065. This is required so that
  11066. the system knows that mounting the file system depends on having the
  11067. corresponding device mapping established.
  11068. @item @code{flags} (default: @code{'()})
  11069. This is a list of symbols denoting mount flags. Recognized flags
  11070. include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
  11071. access to special files), @code{no-suid} (ignore setuid and setgid
  11072. bits), @code{no-atime} (do not update file access times),
  11073. @code{strict-atime} (update file access time), @code{lazy-time} (only
  11074. update time on the in-memory version of the file inode), and
  11075. @code{no-exec} (disallow program execution).
  11076. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
  11077. Manual}, for more information on these flags.
  11078. @item @code{options} (default: @code{#f})
  11079. This is either @code{#f}, or a string denoting mount options passed to
  11080. the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
  11081. Library Reference Manual}, for details and run @command{man 8 mount} for
  11082. options for various file systems. Note that the
  11083. @code{file-system-options->alist} and @code{alist->file-system-options}
  11084. procedures from @code{(gnu system file-systems)} can be used to convert
  11085. file system options given as an association list to the string
  11086. representation, and vice-versa.
  11087. @item @code{mount?} (default: @code{#t})
  11088. This value indicates whether to automatically mount the file system when
  11089. the system is brought up. When set to @code{#f}, the file system gets
  11090. an entry in @file{/etc/fstab} (read by the @command{mount} command) but
  11091. is not automatically mounted.
  11092. @item @code{needed-for-boot?} (default: @code{#f})
  11093. This Boolean value indicates whether the file system is needed when
  11094. booting. If that is true, then the file system is mounted when the
  11095. initial RAM disk (initrd) is loaded. This is always the case, for
  11096. instance, for the root file system.
  11097. @item @code{check?} (default: @code{#t})
  11098. This Boolean indicates whether the file system needs to be checked for
  11099. errors before being mounted.
  11100. @item @code{create-mount-point?} (default: @code{#f})
  11101. When true, the mount point is created if it does not exist yet.
  11102. @item @code{mount-may-fail?} (default: @code{#f})
  11103. When true, this indicates that mounting this file system can fail but
  11104. that should not be considered an error. This is useful in unusual
  11105. cases; an example of this is @code{efivarfs}, a file system that can
  11106. only be mounted on EFI/UEFI systems.
  11107. @item @code{dependencies} (default: @code{'()})
  11108. This is a list of @code{<file-system>} or @code{<mapped-device>} objects
  11109. representing file systems that must be mounted or mapped devices that
  11110. must be opened before (and unmounted or closed after) this one.
  11111. As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
  11112. a dependency of @file{/sys/fs/cgroup/cpu} and
  11113. @file{/sys/fs/cgroup/memory}.
  11114. Another example is a file system that depends on a mapped device, for
  11115. example for an encrypted partition (@pxref{Mapped Devices}).
  11116. @end table
  11117. @end deftp
  11118. @deffn {Scheme Procedure} file-system-label @var{str}
  11119. This procedure returns an opaque file system label from @var{str}, a
  11120. string:
  11121. @lisp
  11122. (file-system-label "home")
  11123. @result{} #<file-system-label "home">
  11124. @end lisp
  11125. File system labels are used to refer to file systems by label rather
  11126. than by device name. See above for examples.
  11127. @end deffn
  11128. The @code{(gnu system file-systems)} exports the following useful
  11129. variables.
  11130. @defvr {Scheme Variable} %base-file-systems
  11131. These are essential file systems that are required on normal systems,
  11132. such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
  11133. below). Operating system declarations should always contain at least
  11134. these.
  11135. @end defvr
  11136. @defvr {Scheme Variable} %pseudo-terminal-file-system
  11137. This is the file system to be mounted as @file{/dev/pts}. It supports
  11138. @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
  11139. functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
  11140. Manual}). Pseudo-terminals are used by terminal emulators such as
  11141. @command{xterm}.
  11142. @end defvr
  11143. @defvr {Scheme Variable} %shared-memory-file-system
  11144. This file system is mounted as @file{/dev/shm} and is used to support
  11145. memory sharing across processes (@pxref{Memory-mapped I/O,
  11146. @code{shm_open},, libc, The GNU C Library Reference Manual}).
  11147. @end defvr
  11148. @defvr {Scheme Variable} %immutable-store
  11149. This file system performs a read-only ``bind mount'' of
  11150. @file{/gnu/store}, making it read-only for all the users including
  11151. @code{root}. This prevents against accidental modification by software
  11152. running as @code{root} or by system administrators.
  11153. The daemon itself is still able to write to the store: it remounts it
  11154. read-write in its own ``name space.''
  11155. @end defvr
  11156. @defvr {Scheme Variable} %binary-format-file-system
  11157. The @code{binfmt_misc} file system, which allows handling of arbitrary
  11158. executable file types to be delegated to user space. This requires the
  11159. @code{binfmt.ko} kernel module to be loaded.
  11160. @end defvr
  11161. @defvr {Scheme Variable} %fuse-control-file-system
  11162. The @code{fusectl} file system, which allows unprivileged users to mount
  11163. and unmount user-space FUSE file systems. This requires the
  11164. @code{fuse.ko} kernel module to be loaded.
  11165. @end defvr
  11166. The @code{(gnu system uuid)} module provides tools to deal with file
  11167. system ``unique identifiers'' (UUIDs).
  11168. @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
  11169. Return an opaque UUID (unique identifier) object of the given @var{type}
  11170. (a symbol) by parsing @var{str} (a string):
  11171. @lisp
  11172. (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
  11173. @result{} #<<uuid> type: dce bv: @dots{}>
  11174. (uuid "1234-ABCD" 'fat)
  11175. @result{} #<<uuid> type: fat bv: @dots{}>
  11176. @end lisp
  11177. @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
  11178. @code{ntfs}, or one of the commonly found synonyms for these.
  11179. UUIDs are another way to unambiguously refer to file systems in
  11180. operating system configuration. See the examples above.
  11181. @end deffn
  11182. @node Btrfs file system
  11183. @subsection Btrfs file system
  11184. The Btrfs has special features, such as subvolumes, that merit being
  11185. explained in more details. The following section attempts to cover
  11186. basic as well as complex uses of a Btrfs file system with the Guix
  11187. System.
  11188. In its simplest usage, a Btrfs file system can be described, for
  11189. example, by:
  11190. @lisp
  11191. (file-system
  11192. (mount-point "/home")
  11193. (type "btrfs")
  11194. (device (file-system-label "my-home")))
  11195. @end lisp
  11196. The example below is more complex, as it makes use of a Btrfs
  11197. subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
  11198. @code{my-btrfs-pool}, and is located on an encrypted device (hence the
  11199. dependency on @code{mapped-devices}):
  11200. @lisp
  11201. (file-system
  11202. (device (file-system-label "my-btrfs-pool"))
  11203. (mount-point "/")
  11204. (type "btrfs")
  11205. (options "subvol=rootfs")
  11206. (dependencies mapped-devices))
  11207. @end lisp
  11208. Some bootloaders, for example GRUB, only mount a Btrfs partition at its
  11209. top level during the early boot, and rely on their configuration to
  11210. refer to the correct subvolume path within that top level. The
  11211. bootloaders operating in this way typically produce their configuration
  11212. on a running system where the Btrfs partitions are already mounted and
  11213. where the subvolume information is readily available. As an example,
  11214. @command{grub-mkconfig}, the configuration generator command shipped
  11215. with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
  11216. path of a subvolume.
  11217. The Guix System produces a bootloader configuration using the operating
  11218. system configuration as its sole input; it is therefore necessary to
  11219. extract the subvolume name on which @file{/gnu/store} lives (if any)
  11220. from that operating system configuration. To better illustrate,
  11221. consider a subvolume named 'rootfs' which contains the root file system
  11222. data. In such situation, the GRUB bootloader would only see the top
  11223. level of the root Btrfs partition, e.g.:
  11224. @example
  11225. / (top level)
  11226. ├── rootfs (subvolume directory)
  11227. ├── gnu (normal directory)
  11228. ├── store (normal directory)
  11229. [...]
  11230. @end example
  11231. Thus, the subvolume name must be prepended to the @file{/gnu/store} path
  11232. of the kernel, initrd binaries and any other files referred to in the
  11233. GRUB configuration that must be found during the early boot.
  11234. The next example shows a nested hierarchy of subvolumes and
  11235. directories:
  11236. @example
  11237. / (top level)
  11238. ├── rootfs (subvolume)
  11239. ├── gnu (normal directory)
  11240. ├── store (subvolume)
  11241. [...]
  11242. @end example
  11243. This scenario would work without mounting the 'store' subvolume.
  11244. Mounting 'rootfs' is sufficient, since the subvolume name matches its
  11245. intended mount point in the file system hierarchy. Alternatively, the
  11246. 'store' subvolume could be referred to by setting the @code{subvol}
  11247. option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
  11248. Finally, a more contrived example of nested subvolumes:
  11249. @example
  11250. / (top level)
  11251. ├── root-snapshots (subvolume)
  11252. ├── root-current (subvolume)
  11253. ├── guix-store (subvolume)
  11254. [...]
  11255. @end example
  11256. Here, the 'guix-store' subvolume doesn't match its intended mount point,
  11257. so it is necessary to mount it. The subvolume must be fully specified,
  11258. by passing its file name to the @code{subvol} option. To illustrate,
  11259. the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
  11260. a file system declaration such as:
  11261. @lisp
  11262. (file-system
  11263. (device (file-system-label "btrfs-pool-1"))
  11264. (mount-point "/gnu/store")
  11265. (type "btrfs")
  11266. (options "subvol=root-snapshots/root-current/guix-store,\
  11267. compress-force=zstd,space_cache=v2"))
  11268. @end lisp
  11269. @node Mapped Devices
  11270. @section Mapped Devices
  11271. @cindex device mapping
  11272. @cindex mapped devices
  11273. The Linux kernel has a notion of @dfn{device mapping}: a block device,
  11274. such as a hard disk partition, can be @dfn{mapped} into another device,
  11275. usually in @code{/dev/mapper/},
  11276. with additional processing over the data that flows through
  11277. it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
  11278. concept of a ``mapped device'' and that of a file system: both boil down
  11279. to @emph{translating} input/output operations made on a file to
  11280. operations on its backing store. Thus, the Hurd implements mapped
  11281. devices, like file systems, using the generic @dfn{translator} mechanism
  11282. (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
  11283. typical example is encryption device mapping: all writes to the mapped
  11284. device are encrypted, and all reads are deciphered, transparently.
  11285. Guix extends this notion by considering any device or set of devices that
  11286. are @dfn{transformed} in some way to create a new device; for instance,
  11287. RAID devices are obtained by @dfn{assembling} several other devices, such
  11288. as hard disks or partitions, into a new one that behaves as one partition.
  11289. Mapped devices are declared using the @code{mapped-device} form,
  11290. defined as follows; for examples, see below.
  11291. @deftp {Data Type} mapped-device
  11292. Objects of this type represent device mappings that will be made when
  11293. the system boots up.
  11294. @table @code
  11295. @item source
  11296. This is either a string specifying the name of the block device to be mapped,
  11297. such as @code{"/dev/sda3"}, or a list of such strings when several devices
  11298. need to be assembled for creating a new one. In case of LVM this is a
  11299. string specifying name of the volume group to be mapped.
  11300. @item target
  11301. This string specifies the name of the resulting mapped device. For
  11302. kernel mappers such as encrypted devices of type @code{luks-device-mapping},
  11303. specifying @code{"my-partition"} leads to the creation of
  11304. the @code{"/dev/mapper/my-partition"} device.
  11305. For RAID devices of type @code{raid-device-mapping}, the full device name
  11306. such as @code{"/dev/md0"} needs to be given.
  11307. LVM logical volumes of type @code{lvm-device-mapping} need to
  11308. be specified as @code{"VGNAME-LVNAME"}.
  11309. @item targets
  11310. This list of strings specifies names of the resulting mapped devices in case
  11311. there are several. The format is identical to @var{target}.
  11312. @item type
  11313. This must be a @code{mapped-device-kind} object, which specifies how
  11314. @var{source} is mapped to @var{target}.
  11315. @end table
  11316. @end deftp
  11317. @defvr {Scheme Variable} luks-device-mapping
  11318. This defines LUKS block device encryption using the @command{cryptsetup}
  11319. command from the package with the same name. It relies on the
  11320. @code{dm-crypt} Linux kernel module.
  11321. @end defvr
  11322. @defvr {Scheme Variable} raid-device-mapping
  11323. This defines a RAID device, which is assembled using the @code{mdadm}
  11324. command from the package with the same name. It requires a Linux kernel
  11325. module for the appropriate RAID level to be loaded, such as @code{raid456}
  11326. for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
  11327. @end defvr
  11328. @cindex LVM, logical volume manager
  11329. @defvr {Scheme Variable} lvm-device-mapping
  11330. This defines one or more logical volumes for the Linux
  11331. @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
  11332. The volume group is activated by the @command{vgchange} command from the
  11333. @code{lvm2} package.
  11334. @end defvr
  11335. @cindex disk encryption
  11336. @cindex LUKS
  11337. The following example specifies a mapping from @file{/dev/sda3} to
  11338. @file{/dev/mapper/home} using LUKS---the
  11339. @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
  11340. standard mechanism for disk encryption.
  11341. The @file{/dev/mapper/home}
  11342. device can then be used as the @code{device} of a @code{file-system}
  11343. declaration (@pxref{File Systems}).
  11344. @lisp
  11345. (mapped-device
  11346. (source "/dev/sda3")
  11347. (target "home")
  11348. (type luks-device-mapping))
  11349. @end lisp
  11350. Alternatively, to become independent of device numbering, one may obtain
  11351. the LUKS UUID (@dfn{unique identifier}) of the source device by a
  11352. command like:
  11353. @example
  11354. cryptsetup luksUUID /dev/sda3
  11355. @end example
  11356. and use it as follows:
  11357. @lisp
  11358. (mapped-device
  11359. (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
  11360. (target "home")
  11361. (type luks-device-mapping))
  11362. @end lisp
  11363. @cindex swap encryption
  11364. It is also desirable to encrypt swap space, since swap space may contain
  11365. sensitive data. One way to accomplish that is to use a swap file in a
  11366. file system on a device mapped via LUKS encryption. In this way, the
  11367. swap file is encrypted because the entire device is encrypted.
  11368. @xref{Preparing for Installation,,Disk Partitioning}, for an example.
  11369. A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
  11370. may be declared as follows:
  11371. @lisp
  11372. (mapped-device
  11373. (source (list "/dev/sda1" "/dev/sdb1"))
  11374. (target "/dev/md0")
  11375. (type raid-device-mapping))
  11376. @end lisp
  11377. The @file{/dev/md0} device can then be used as the @code{device} of a
  11378. @code{file-system} declaration (@pxref{File Systems}).
  11379. Note that the RAID level need not be given; it is chosen during the
  11380. initial creation and formatting of the RAID device and is determined
  11381. automatically later.
  11382. LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
  11383. be declared as follows:
  11384. @lisp
  11385. (mapped-device
  11386. (source "vg0")
  11387. (targets (list "vg0-alpha" "vg0-beta"))
  11388. (type lvm-device-mapping))
  11389. @end lisp
  11390. Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
  11391. then be used as the @code{device} of a @code{file-system} declaration
  11392. (@pxref{File Systems}).
  11393. @node User Accounts
  11394. @section User Accounts
  11395. @cindex users
  11396. @cindex accounts
  11397. @cindex user accounts
  11398. User accounts and groups are entirely managed through the
  11399. @code{operating-system} declaration. They are specified with the
  11400. @code{user-account} and @code{user-group} forms:
  11401. @lisp
  11402. (user-account
  11403. (name "alice")
  11404. (group "users")
  11405. (supplementary-groups '("wheel" ;allow use of sudo, etc.
  11406. "audio" ;sound card
  11407. "video" ;video devices such as webcams
  11408. "cdrom")) ;the good ol' CD-ROM
  11409. (comment "Bob's sister"))
  11410. @end lisp
  11411. Here's a user account that uses a different shell and a custom home
  11412. directory (the default would be @file{"/home/bob"}):
  11413. @lisp
  11414. (user-account
  11415. (name "bob")
  11416. (group "users")
  11417. (comment "Alice's bro")
  11418. (shell (file-append zsh "/bin/zsh"))
  11419. (home-directory "/home/robert"))
  11420. @end lisp
  11421. When booting or upon completion of @command{guix system reconfigure},
  11422. the system ensures that only the user accounts and groups specified in
  11423. the @code{operating-system} declaration exist, and with the specified
  11424. properties. Thus, account or group creations or modifications made by
  11425. directly invoking commands such as @command{useradd} are lost upon
  11426. reconfiguration or reboot. This ensures that the system remains exactly
  11427. as declared.
  11428. @deftp {Data Type} user-account
  11429. Objects of this type represent user accounts. The following members may
  11430. be specified:
  11431. @table @asis
  11432. @item @code{name}
  11433. The name of the user account.
  11434. @item @code{group}
  11435. @cindex groups
  11436. This is the name (a string) or identifier (a number) of the user group
  11437. this account belongs to.
  11438. @item @code{supplementary-groups} (default: @code{'()})
  11439. Optionally, this can be defined as a list of group names that this
  11440. account belongs to.
  11441. @item @code{uid} (default: @code{#f})
  11442. This is the user ID for this account (a number), or @code{#f}. In the
  11443. latter case, a number is automatically chosen by the system when the
  11444. account is created.
  11445. @item @code{comment} (default: @code{""})
  11446. A comment about the account, such as the account owner's full name.
  11447. @item @code{home-directory}
  11448. This is the name of the home directory for the account.
  11449. @item @code{create-home-directory?} (default: @code{#t})
  11450. Indicates whether the home directory of this account should be created
  11451. if it does not exist yet.
  11452. @item @code{shell} (default: Bash)
  11453. This is a G-expression denoting the file name of a program to be used as
  11454. the shell (@pxref{G-Expressions}). For example, you would refer to the
  11455. Bash executable like this:
  11456. @lisp
  11457. (file-append bash "/bin/bash")
  11458. @end lisp
  11459. @noindent
  11460. ... and to the Zsh executable like that:
  11461. @lisp
  11462. (file-append zsh "/bin/zsh")
  11463. @end lisp
  11464. @item @code{system?} (default: @code{#f})
  11465. This Boolean value indicates whether the account is a ``system''
  11466. account. System accounts are sometimes treated specially; for instance,
  11467. graphical login managers do not list them.
  11468. @anchor{user-account-password}
  11469. @cindex password, for user accounts
  11470. @item @code{password} (default: @code{#f})
  11471. You would normally leave this field to @code{#f}, initialize user
  11472. passwords as @code{root} with the @command{passwd} command, and then let
  11473. users change it with @command{passwd}. Passwords set with
  11474. @command{passwd} are of course preserved across reboot and
  11475. reconfiguration.
  11476. If you @emph{do} want to set an initial password for an account, then
  11477. this field must contain the encrypted password, as a string. You can use the
  11478. @code{crypt} procedure for this purpose:
  11479. @lisp
  11480. (user-account
  11481. (name "charlie")
  11482. (group "users")
  11483. ;; Specify a SHA-512-hashed initial password.
  11484. (password (crypt "InitialPassword!" "$6$abc")))
  11485. @end lisp
  11486. @quotation Note
  11487. The hash of this initial password will be available in a file in
  11488. @file{/gnu/store}, readable by all the users, so this method must be used with
  11489. care.
  11490. @end quotation
  11491. @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
  11492. more information on password encryption, and @ref{Encryption,,, guile, GNU
  11493. Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
  11494. @end table
  11495. @end deftp
  11496. @cindex groups
  11497. User group declarations are even simpler:
  11498. @lisp
  11499. (user-group (name "students"))
  11500. @end lisp
  11501. @deftp {Data Type} user-group
  11502. This type is for, well, user groups. There are just a few fields:
  11503. @table @asis
  11504. @item @code{name}
  11505. The name of the group.
  11506. @item @code{id} (default: @code{#f})
  11507. The group identifier (a number). If @code{#f}, a new number is
  11508. automatically allocated when the group is created.
  11509. @item @code{system?} (default: @code{#f})
  11510. This Boolean value indicates whether the group is a ``system'' group.
  11511. System groups have low numerical IDs.
  11512. @item @code{password} (default: @code{#f})
  11513. What, user groups can have a password? Well, apparently yes. Unless
  11514. @code{#f}, this field specifies the password of the group.
  11515. @end table
  11516. @end deftp
  11517. For convenience, a variable lists all the basic user groups one may
  11518. expect:
  11519. @defvr {Scheme Variable} %base-groups
  11520. This is the list of basic user groups that users and/or packages expect
  11521. to be present on the system. This includes groups such as ``root'',
  11522. ``wheel'', and ``users'', as well as groups used to control access to
  11523. specific devices such as ``audio'', ``disk'', and ``cdrom''.
  11524. @end defvr
  11525. @defvr {Scheme Variable} %base-user-accounts
  11526. This is the list of basic system accounts that programs may expect to
  11527. find on a GNU/Linux system, such as the ``nobody'' account.
  11528. Note that the ``root'' account is not included here. It is a
  11529. special-case and is automatically added whether or not it is specified.
  11530. @end defvr
  11531. @node Keyboard Layout
  11532. @section Keyboard Layout
  11533. @cindex keyboard layout
  11534. @cindex keymap
  11535. To specify what each key of your keyboard does, you need to tell the operating
  11536. system what @dfn{keyboard layout} you want to use. The default, when nothing
  11537. is specified, is the US English QWERTY layout for 105-key PC keyboards.
  11538. However, German speakers will usually prefer the German QWERTZ layout, French
  11539. speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
  11540. or bépo, and they might even want to further customize the effect of some of
  11541. the keys. This section explains how to get that done.
  11542. @cindex keyboard layout, definition
  11543. There are three components that will want to know about your keyboard layout:
  11544. @itemize
  11545. @item
  11546. The @emph{bootloader} may want to know what keyboard layout you want to use
  11547. (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
  11548. you want, for instance, to make sure that you can type the passphrase of your
  11549. encrypted root partition using the right layout.
  11550. @item
  11551. The @emph{operating system kernel}, Linux, will need that so that the console
  11552. is properly configured (@pxref{operating-system Reference,
  11553. @code{keyboard-layout}}).
  11554. @item
  11555. The @emph{graphical display server}, usually Xorg, also has its own idea of
  11556. the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
  11557. @end itemize
  11558. Guix allows you to configure all three separately but, fortunately, it allows
  11559. you to share the same keyboard layout for all three components.
  11560. @cindex XKB, keyboard layouts
  11561. Keyboard layouts are represented by records created by the
  11562. @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
  11563. the X Keyboard extension (XKB), each layout has four attributes: a name (often
  11564. a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
  11565. optional variant name, an optional keyboard model name, and a possibly empty
  11566. list of additional options. In most cases the layout name is all you care
  11567. about.
  11568. @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
  11569. [#:model] [#:options '()]
  11570. Return a new keyboard layout with the given @var{name} and @var{variant}.
  11571. @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
  11572. string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
  11573. @code{xkeyboard-config} package for valid options.
  11574. @end deffn
  11575. Here are a few examples:
  11576. @lisp
  11577. ;; The German QWERTZ layout. Here we assume a standard
  11578. ;; "pc105" keyboard model.
  11579. (keyboard-layout "de")
  11580. ;; The bépo variant of the French layout.
  11581. (keyboard-layout "fr" "bepo")
  11582. ;; The Catalan layout.
  11583. (keyboard-layout "es" "cat")
  11584. ;; Arabic layout with "Alt-Shift" to switch to US layout.
  11585. (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
  11586. ;; The Latin American Spanish layout. In addition, the
  11587. ;; "Caps Lock" key is used as an additional "Ctrl" key,
  11588. ;; and the "Menu" key is used as a "Compose" key to enter
  11589. ;; accented letters.
  11590. (keyboard-layout "latam"
  11591. #:options '("ctrl:nocaps" "compose:menu"))
  11592. ;; The Russian layout for a ThinkPad keyboard.
  11593. (keyboard-layout "ru" #:model "thinkpad")
  11594. ;; The "US international" layout, which is the US layout plus
  11595. ;; dead keys to enter accented characters. This is for an
  11596. ;; Apple MacBook keyboard.
  11597. (keyboard-layout "us" "intl" #:model "macbook78")
  11598. @end lisp
  11599. See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
  11600. for a complete list of supported layouts, variants, and models.
  11601. @cindex keyboard layout, configuration
  11602. Let's say you want your system to use the Turkish keyboard layout throughout
  11603. your system---bootloader, console, and Xorg. Here's what your system
  11604. configuration would look like:
  11605. @findex set-xorg-configuration
  11606. @lisp
  11607. ;; Using the Turkish layout for the bootloader, the console,
  11608. ;; and for Xorg.
  11609. (operating-system
  11610. ;; ...
  11611. (keyboard-layout (keyboard-layout "tr")) ;for the console
  11612. (bootloader (bootloader-configuration
  11613. (bootloader grub-efi-bootloader)
  11614. (target "/boot/efi")
  11615. (keyboard-layout keyboard-layout))) ;for GRUB
  11616. (services (cons (set-xorg-configuration
  11617. (xorg-configuration ;for Xorg
  11618. (keyboard-layout keyboard-layout)))
  11619. %desktop-services)))
  11620. @end lisp
  11621. In the example above, for GRUB and for Xorg, we just refer to the
  11622. @code{keyboard-layout} field defined above, but we could just as well refer to
  11623. a different layout. The @code{set-xorg-configuration} procedure communicates
  11624. the desired Xorg configuration to the graphical log-in manager, by default
  11625. GDM.
  11626. We've discussed how to specify the @emph{default} keyboard layout of your
  11627. system when it starts, but you can also adjust it at run time:
  11628. @itemize
  11629. @item
  11630. If you're using GNOME, its settings panel has a ``Region & Language'' entry
  11631. where you can select one or more keyboard layouts.
  11632. @item
  11633. Under Xorg, the @command{setxkbmap} command (from the same-named package)
  11634. allows you to change the current layout. For example, this is how you would
  11635. change the layout to US Dvorak:
  11636. @example
  11637. setxkbmap us dvorak
  11638. @end example
  11639. @item
  11640. The @code{loadkeys} command changes the keyboard layout in effect in the Linux
  11641. console. However, note that @code{loadkeys} does @emph{not} use the XKB
  11642. keyboard layout categorization described above. The command below loads the
  11643. French bépo layout:
  11644. @example
  11645. loadkeys fr-bepo
  11646. @end example
  11647. @end itemize
  11648. @node Locales
  11649. @section Locales
  11650. @cindex locale
  11651. A @dfn{locale} defines cultural conventions for a particular language
  11652. and region of the world (@pxref{Locales,,, libc, The GNU C Library
  11653. Reference Manual}). Each locale has a name that typically has the form
  11654. @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
  11655. @code{fr_LU.utf8} designates the locale for the French language, with
  11656. cultural conventions from Luxembourg, and using the UTF-8 encoding.
  11657. @cindex locale definition
  11658. Usually, you will want to specify the default locale for the machine
  11659. using the @code{locale} field of the @code{operating-system} declaration
  11660. (@pxref{operating-system Reference, @code{locale}}).
  11661. The selected locale is automatically added to the @dfn{locale
  11662. definitions} known to the system if needed, with its codeset inferred
  11663. from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
  11664. @code{UTF-8} codeset. Additional locale definitions can be specified in
  11665. the @code{locale-definitions} slot of @code{operating-system}---this is
  11666. useful, for instance, if the codeset could not be inferred from the
  11667. locale name. The default set of locale definitions includes some widely
  11668. used locales, but not all the available locales, in order to save space.
  11669. For instance, to add the North Frisian locale for Germany, the value of
  11670. that field may be:
  11671. @lisp
  11672. (cons (locale-definition
  11673. (name "fy_DE.utf8") (source "fy_DE"))
  11674. %default-locale-definitions)
  11675. @end lisp
  11676. Likewise, to save space, one might want @code{locale-definitions} to
  11677. list only the locales that are actually used, as in:
  11678. @lisp
  11679. (list (locale-definition
  11680. (name "ja_JP.eucjp") (source "ja_JP")
  11681. (charset "EUC-JP")))
  11682. @end lisp
  11683. @vindex LOCPATH
  11684. The compiled locale definitions are available at
  11685. @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
  11686. version, which is the default location where the GNU@tie{}libc provided
  11687. by Guix looks for locale data. This can be overridden using the
  11688. @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
  11689. @env{LOCPATH} and locale packages}).
  11690. The @code{locale-definition} form is provided by the @code{(gnu system
  11691. locale)} module. Details are given below.
  11692. @deftp {Data Type} locale-definition
  11693. This is the data type of a locale definition.
  11694. @table @asis
  11695. @item @code{name}
  11696. The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
  11697. Reference Manual}, for more information on locale names.
  11698. @item @code{source}
  11699. The name of the source for that locale. This is typically the
  11700. @code{@var{language}_@var{territory}} part of the locale name.
  11701. @item @code{charset} (default: @code{"UTF-8"})
  11702. The ``character set'' or ``code set'' for that locale,
  11703. @uref{https://www.iana.org/assignments/character-sets, as defined by
  11704. IANA}.
  11705. @end table
  11706. @end deftp
  11707. @defvr {Scheme Variable} %default-locale-definitions
  11708. A list of commonly used UTF-8 locales, used as the default
  11709. value of the @code{locale-definitions} field of @code{operating-system}
  11710. declarations.
  11711. @cindex locale name
  11712. @cindex normalized codeset in locale names
  11713. These locale definitions use the @dfn{normalized codeset} for the part
  11714. that follows the dot in the name (@pxref{Using gettextized software,
  11715. normalized codeset,, libc, The GNU C Library Reference Manual}). So for
  11716. instance it has @code{uk_UA.utf8} but @emph{not}, say,
  11717. @code{uk_UA.UTF-8}.
  11718. @end defvr
  11719. @subsection Locale Data Compatibility Considerations
  11720. @cindex incompatibility, of locale data
  11721. @code{operating-system} declarations provide a @code{locale-libcs} field
  11722. to specify the GNU@tie{}libc packages that are used to compile locale
  11723. declarations (@pxref{operating-system Reference}). ``Why would I
  11724. care?'', you may ask. Well, it turns out that the binary format of
  11725. locale data is occasionally incompatible from one libc version to
  11726. another.
  11727. @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
  11728. @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
  11729. For instance, a program linked against libc version 2.21 is unable to
  11730. read locale data produced with libc 2.22; worse, that program
  11731. @emph{aborts} instead of simply ignoring the incompatible locale
  11732. data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
  11733. the incompatible locale data, which is already an improvement.}.
  11734. Similarly, a program linked against libc 2.22 can read most, but not
  11735. all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
  11736. data is incompatible); thus calls to @code{setlocale} may fail, but
  11737. programs will not abort.
  11738. The ``problem'' with Guix is that users have a lot of freedom: They can
  11739. choose whether and when to upgrade software in their profiles, and might
  11740. be using a libc version different from the one the system administrator
  11741. used to build the system-wide locale data.
  11742. Fortunately, unprivileged users can also install their own locale data
  11743. and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
  11744. @env{GUIX_LOCPATH} and locale packages}).
  11745. Still, it is best if the system-wide locale data at
  11746. @file{/run/current-system/locale} is built for all the libc versions
  11747. actually in use on the system, so that all the programs can access
  11748. it---this is especially crucial on a multi-user system. To do that, the
  11749. administrator can specify several libc packages in the
  11750. @code{locale-libcs} field of @code{operating-system}:
  11751. @lisp
  11752. (use-package-modules base)
  11753. (operating-system
  11754. ;; @dots{}
  11755. (locale-libcs (list glibc-2.21 (canonical-package glibc))))
  11756. @end lisp
  11757. This example would lead to a system containing locale definitions for
  11758. both libc 2.21 and the current version of libc in
  11759. @file{/run/current-system/locale}.
  11760. @node Services
  11761. @section Services
  11762. @cindex system services
  11763. An important part of preparing an @code{operating-system} declaration is
  11764. listing @dfn{system services} and their configuration (@pxref{Using the
  11765. Configuration System}). System services are typically daemons launched
  11766. when the system boots, or other actions needed at that time---e.g.,
  11767. configuring network access.
  11768. Guix has a broad definition of ``service'' (@pxref{Service
  11769. Composition}), but many services are managed by the GNU@tie{}Shepherd
  11770. (@pxref{Shepherd Services}). On a running system, the @command{herd}
  11771. command allows you to list the available services, show their status,
  11772. start and stop them, or do other specific operations (@pxref{Jump
  11773. Start,,, shepherd, The GNU Shepherd Manual}). For example:
  11774. @example
  11775. # herd status
  11776. @end example
  11777. The above command, run as @code{root}, lists the currently defined
  11778. services. The @command{herd doc} command shows a synopsis of the given
  11779. service and its associated actions:
  11780. @example
  11781. # herd doc nscd
  11782. Run libc's name service cache daemon (nscd).
  11783. # herd doc nscd action invalidate
  11784. invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
  11785. @end example
  11786. The @command{start}, @command{stop}, and @command{restart} sub-commands
  11787. have the effect you would expect. For instance, the commands below stop
  11788. the nscd service and restart the Xorg display server:
  11789. @example
  11790. # herd stop nscd
  11791. Service nscd has been stopped.
  11792. # herd restart xorg-server
  11793. Service xorg-server has been stopped.
  11794. Service xorg-server has been started.
  11795. @end example
  11796. The following sections document the available services, starting with
  11797. the core services, that may be used in an @code{operating-system}
  11798. declaration.
  11799. @menu
  11800. * Base Services:: Essential system services.
  11801. * Scheduled Job Execution:: The mcron service.
  11802. * Log Rotation:: The rottlog service.
  11803. * Networking Services:: Network setup, SSH daemon, etc.
  11804. * Unattended Upgrades:: Automated system upgrades.
  11805. * X Window:: Graphical display.
  11806. * Printing Services:: Local and remote printer support.
  11807. * Desktop Services:: D-Bus and desktop services.
  11808. * Sound Services:: ALSA and Pulseaudio services.
  11809. * Database Services:: SQL databases, key-value stores, etc.
  11810. * Mail Services:: IMAP, POP3, SMTP, and all that.
  11811. * Messaging Services:: Messaging services.
  11812. * Telephony Services:: Telephony services.
  11813. * Monitoring Services:: Monitoring services.
  11814. * Kerberos Services:: Kerberos services.
  11815. * LDAP Services:: LDAP services.
  11816. * Web Services:: Web servers.
  11817. * Certificate Services:: TLS certificates via Let's Encrypt.
  11818. * DNS Services:: DNS daemons.
  11819. * VPN Services:: VPN daemons.
  11820. * Network File System:: NFS related services.
  11821. * Continuous Integration:: The Cuirass service.
  11822. * Power Management Services:: Extending battery life.
  11823. * Audio Services:: The MPD.
  11824. * Virtualization Services:: Virtualization services.
  11825. * Version Control Services:: Providing remote access to Git repositories.
  11826. * Game Services:: Game servers.
  11827. * PAM Mount Service:: Service to mount volumes when logging in.
  11828. * Guix Services:: Services relating specifically to Guix.
  11829. * Linux Services:: Services tied to the Linux kernel.
  11830. * Hurd Services:: Services specific for a Hurd System.
  11831. * Miscellaneous Services:: Other services.
  11832. @end menu
  11833. @node Base Services
  11834. @subsection Base Services
  11835. The @code{(gnu services base)} module provides definitions for the basic
  11836. services that one expects from the system. The services exported by
  11837. this module are listed below.
  11838. @defvr {Scheme Variable} %base-services
  11839. This variable contains a list of basic services (@pxref{Service Types
  11840. and Services}, for more information on service objects) one would
  11841. expect from the system: a login service (mingetty) on each tty, syslogd,
  11842. the libc name service cache daemon (nscd), the udev device manager, and
  11843. more.
  11844. This is the default value of the @code{services} field of
  11845. @code{operating-system} declarations. Usually, when customizing a
  11846. system, you will want to append services to @code{%base-services}, like
  11847. this:
  11848. @lisp
  11849. (append (list (service avahi-service-type)
  11850. (service openssh-service-type))
  11851. %base-services)
  11852. @end lisp
  11853. @end defvr
  11854. @defvr {Scheme Variable} special-files-service-type
  11855. This is the service that sets up ``special files'' such as
  11856. @file{/bin/sh}; an instance of it is part of @code{%base-services}.
  11857. The value associated with @code{special-files-service-type} services
  11858. must be a list of tuples where the first element is the ``special file''
  11859. and the second element is its target. By default it is:
  11860. @cindex @file{/bin/sh}
  11861. @cindex @file{sh}, in @file{/bin}
  11862. @lisp
  11863. `(("/bin/sh" ,(file-append bash "/bin/sh")))
  11864. @end lisp
  11865. @cindex @file{/usr/bin/env}
  11866. @cindex @file{env}, in @file{/usr/bin}
  11867. If you want to add, say, @code{/usr/bin/env} to your system, you can
  11868. change it to:
  11869. @lisp
  11870. `(("/bin/sh" ,(file-append bash "/bin/sh"))
  11871. ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
  11872. @end lisp
  11873. Since this is part of @code{%base-services}, you can use
  11874. @code{modify-services} to customize the set of special files
  11875. (@pxref{Service Reference, @code{modify-services}}). But the simple way
  11876. to add a special file is @i{via} the @code{extra-special-file} procedure
  11877. (see below).
  11878. @end defvr
  11879. @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
  11880. Use @var{target} as the ``special file'' @var{file}.
  11881. For example, adding the following lines to the @code{services} field of
  11882. your operating system declaration leads to a @file{/usr/bin/env}
  11883. symlink:
  11884. @lisp
  11885. (extra-special-file "/usr/bin/env"
  11886. (file-append coreutils "/bin/env"))
  11887. @end lisp
  11888. @end deffn
  11889. @deffn {Scheme Procedure} host-name-service @var{name}
  11890. Return a service that sets the host name to @var{name}.
  11891. @end deffn
  11892. @defvr {Scheme Variable} console-font-service-type
  11893. Install the given fonts on the specified ttys (fonts are per
  11894. virtual console on the kernel Linux). The value of this service is a list of
  11895. tty/font pairs. The font can be the name of a font provided by the @code{kbd}
  11896. package or any valid argument to @command{setfont}, as in this example:
  11897. @lisp
  11898. `(("tty1" . "LatGrkCyr-8x16")
  11899. ("tty2" . ,(file-append
  11900. font-tamzen
  11901. "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
  11902. ("tty3" . ,(file-append
  11903. font-terminus
  11904. "/share/consolefonts/ter-132n"))) ; for HDPI
  11905. @end lisp
  11906. @end defvr
  11907. @deffn {Scheme Procedure} login-service @var{config}
  11908. Return a service to run login according to @var{config}, a
  11909. @code{<login-configuration>} object, which specifies the message of the day,
  11910. among other things.
  11911. @end deffn
  11912. @deftp {Data Type} login-configuration
  11913. This is the data type representing the configuration of login.
  11914. @table @asis
  11915. @item @code{motd}
  11916. @cindex message of the day
  11917. A file-like object containing the ``message of the day''.
  11918. @item @code{allow-empty-passwords?} (default: @code{#t})
  11919. Allow empty passwords by default so that first-time users can log in when
  11920. the 'root' account has just been created.
  11921. @end table
  11922. @end deftp
  11923. @deffn {Scheme Procedure} mingetty-service @var{config}
  11924. Return a service to run mingetty according to @var{config}, a
  11925. @code{<mingetty-configuration>} object, which specifies the tty to run, among
  11926. other things.
  11927. @end deffn
  11928. @deftp {Data Type} mingetty-configuration
  11929. This is the data type representing the configuration of Mingetty, which
  11930. provides the default implementation of virtual console log-in.
  11931. @table @asis
  11932. @item @code{tty}
  11933. The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
  11934. @item @code{auto-login} (default: @code{#f})
  11935. When true, this field must be a string denoting the user name under
  11936. which the system automatically logs in. When it is @code{#f}, a
  11937. user name and password must be entered to log in.
  11938. @item @code{login-program} (default: @code{#f})
  11939. This must be either @code{#f}, in which case the default log-in program
  11940. is used (@command{login} from the Shadow tool suite), or a gexp denoting
  11941. the name of the log-in program.
  11942. @item @code{login-pause?} (default: @code{#f})
  11943. When set to @code{#t} in conjunction with @var{auto-login}, the user
  11944. will have to press a key before the log-in shell is launched.
  11945. @item @code{clear-on-logout?} (default: @code{#t})
  11946. When set to @code{#t}, the screen will be cleared after logout.
  11947. @item @code{mingetty} (default: @var{mingetty})
  11948. The Mingetty package to use.
  11949. @end table
  11950. @end deftp
  11951. @deffn {Scheme Procedure} agetty-service @var{config}
  11952. Return a service to run agetty according to @var{config}, an
  11953. @code{<agetty-configuration>} object, which specifies the tty to run,
  11954. among other things.
  11955. @end deffn
  11956. @deftp {Data Type} agetty-configuration
  11957. This is the data type representing the configuration of agetty, which
  11958. implements virtual and serial console log-in. See the @code{agetty(8)}
  11959. man page for more information.
  11960. @table @asis
  11961. @item @code{tty}
  11962. The name of the console this agetty runs on, as a string---e.g.,
  11963. @code{"ttyS0"}. This argument is optional, it will default to
  11964. a reasonable default serial port used by the kernel Linux.
  11965. For this, if there is a value for an option @code{agetty.tty} in the kernel
  11966. command line, agetty will extract the device name of the serial port
  11967. from it and use that.
  11968. If not and if there is a value for an option @code{console} with a tty in
  11969. the Linux command line, agetty will extract the device name of the
  11970. serial port from it and use that.
  11971. In both cases, agetty will leave the other serial device settings
  11972. (baud rate etc.)@: alone---in the hope that Linux pinned them to the
  11973. correct values.
  11974. @item @code{baud-rate} (default: @code{#f})
  11975. A string containing a comma-separated list of one or more baud rates, in
  11976. descending order.
  11977. @item @code{term} (default: @code{#f})
  11978. A string containing the value used for the @env{TERM} environment
  11979. variable.
  11980. @item @code{eight-bits?} (default: @code{#f})
  11981. When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
  11982. disabled.
  11983. @item @code{auto-login} (default: @code{#f})
  11984. When passed a login name, as a string, the specified user will be logged
  11985. in automatically without prompting for their login name or password.
  11986. @item @code{no-reset?} (default: @code{#f})
  11987. When @code{#t}, don't reset terminal cflags (control modes).
  11988. @item @code{host} (default: @code{#f})
  11989. This accepts a string containing the ``login_host'', which will be written
  11990. into the @file{/var/run/utmpx} file.
  11991. @item @code{remote?} (default: @code{#f})
  11992. When set to @code{#t} in conjunction with @var{host}, this will add an
  11993. @code{-r} fakehost option to the command line of the login program
  11994. specified in @var{login-program}.
  11995. @item @code{flow-control?} (default: @code{#f})
  11996. When set to @code{#t}, enable hardware (RTS/CTS) flow control.
  11997. @item @code{no-issue?} (default: @code{#f})
  11998. When set to @code{#t}, the contents of the @file{/etc/issue} file will
  11999. not be displayed before presenting the login prompt.
  12000. @item @code{init-string} (default: @code{#f})
  12001. This accepts a string that will be sent to the tty or modem before
  12002. sending anything else. It can be used to initialize a modem.
  12003. @item @code{no-clear?} (default: @code{#f})
  12004. When set to @code{#t}, agetty will not clear the screen before showing
  12005. the login prompt.
  12006. @item @code{login-program} (default: (file-append shadow "/bin/login"))
  12007. This must be either a gexp denoting the name of a log-in program, or
  12008. unset, in which case the default value is the @command{login} from the
  12009. Shadow tool suite.
  12010. @item @code{local-line} (default: @code{#f})
  12011. Control the CLOCAL line flag. This accepts one of three symbols as
  12012. arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
  12013. the default value chosen by agetty is @code{'auto}.
  12014. @item @code{extract-baud?} (default: @code{#f})
  12015. When set to @code{#t}, instruct agetty to try to extract the baud rate
  12016. from the status messages produced by certain types of modems.
  12017. @item @code{skip-login?} (default: @code{#f})
  12018. When set to @code{#t}, do not prompt the user for a login name. This
  12019. can be used with @var{login-program} field to use non-standard login
  12020. systems.
  12021. @item @code{no-newline?} (default: @code{#f})
  12022. When set to @code{#t}, do not print a newline before printing the
  12023. @file{/etc/issue} file.
  12024. @c Is this dangerous only when used with login-program, or always?
  12025. @item @code{login-options} (default: @code{#f})
  12026. This option accepts a string containing options that are passed to the
  12027. login program. When used with the @var{login-program}, be aware that a
  12028. malicious user could try to enter a login name containing embedded
  12029. options that could be parsed by the login program.
  12030. @item @code{login-pause} (default: @code{#f})
  12031. When set to @code{#t}, wait for any key before showing the login prompt.
  12032. This can be used in conjunction with @var{auto-login} to save memory by
  12033. lazily spawning shells.
  12034. @item @code{chroot} (default: @code{#f})
  12035. Change root to the specified directory. This option accepts a directory
  12036. path as a string.
  12037. @item @code{hangup?} (default: @code{#f})
  12038. Use the Linux system call @code{vhangup} to do a virtual hangup of the
  12039. specified terminal.
  12040. @item @code{keep-baud?} (default: @code{#f})
  12041. When set to @code{#t}, try to keep the existing baud rate. The baud
  12042. rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
  12043. character.
  12044. @item @code{timeout} (default: @code{#f})
  12045. When set to an integer value, terminate if no user name could be read
  12046. within @var{timeout} seconds.
  12047. @item @code{detect-case?} (default: @code{#f})
  12048. When set to @code{#t}, turn on support for detecting an uppercase-only
  12049. terminal. This setting will detect a login name containing only
  12050. uppercase letters as indicating an uppercase-only terminal and turn on
  12051. some upper-to-lower case conversions. Note that this will not support
  12052. Unicode characters.
  12053. @item @code{wait-cr?} (default: @code{#f})
  12054. When set to @code{#t}, wait for the user or modem to send a
  12055. carriage-return or linefeed character before displaying
  12056. @file{/etc/issue} or login prompt. This is typically used with the
  12057. @var{init-string} option.
  12058. @item @code{no-hints?} (default: @code{#f})
  12059. When set to @code{#t}, do not print hints about Num, Caps, and Scroll
  12060. locks.
  12061. @item @code{no-hostname?} (default: @code{#f})
  12062. By default, the hostname is printed. When this option is set to
  12063. @code{#t}, no hostname will be shown at all.
  12064. @item @code{long-hostname?} (default: @code{#f})
  12065. By default, the hostname is only printed until the first dot. When this
  12066. option is set to @code{#t}, the fully qualified hostname by
  12067. @code{gethostname} or @code{getaddrinfo} is shown.
  12068. @item @code{erase-characters} (default: @code{#f})
  12069. This option accepts a string of additional characters that should be
  12070. interpreted as backspace when the user types their login name.
  12071. @item @code{kill-characters} (default: @code{#f})
  12072. This option accepts a string that should be interpreted to mean ``ignore
  12073. all previous characters'' (also called a ``kill'' character) when the user
  12074. types their login name.
  12075. @item @code{chdir} (default: @code{#f})
  12076. This option accepts, as a string, a directory path that will be changed
  12077. to before login.
  12078. @item @code{delay} (default: @code{#f})
  12079. This options accepts, as an integer, the number of seconds to sleep
  12080. before opening the tty and displaying the login prompt.
  12081. @item @code{nice} (default: @code{#f})
  12082. This option accepts, as an integer, the nice value with which to run the
  12083. @command{login} program.
  12084. @item @code{extra-options} (default: @code{'()})
  12085. This option provides an ``escape hatch'' for the user to provide arbitrary
  12086. command-line arguments to @command{agetty} as a list of strings.
  12087. @end table
  12088. @end deftp
  12089. @deffn {Scheme Procedure} kmscon-service-type @var{config}
  12090. Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
  12091. according to @var{config}, a @code{<kmscon-configuration>} object, which
  12092. specifies the tty to run, among other things.
  12093. @end deffn
  12094. @deftp {Data Type} kmscon-configuration
  12095. This is the data type representing the configuration of Kmscon, which
  12096. implements virtual console log-in.
  12097. @table @asis
  12098. @item @code{virtual-terminal}
  12099. The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
  12100. @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
  12101. A gexp denoting the name of the log-in program. The default log-in program is
  12102. @command{login} from the Shadow tool suite.
  12103. @item @code{login-arguments} (default: @code{'("-p")})
  12104. A list of arguments to pass to @command{login}.
  12105. @item @code{auto-login} (default: @code{#f})
  12106. When passed a login name, as a string, the specified user will be logged
  12107. in automatically without prompting for their login name or password.
  12108. @item @code{hardware-acceleration?} (default: #f)
  12109. Whether to use hardware acceleration.
  12110. @item @code{kmscon} (default: @var{kmscon})
  12111. The Kmscon package to use.
  12112. @end table
  12113. @end deftp
  12114. @cindex name service cache daemon
  12115. @cindex nscd
  12116. @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
  12117. [#:name-services '()]
  12118. Return a service that runs the libc name service cache daemon (nscd) with the
  12119. given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
  12120. Service Switch}, for an example.
  12121. For convenience, the Shepherd service for nscd provides the following actions:
  12122. @table @code
  12123. @item invalidate
  12124. @cindex cache invalidation, nscd
  12125. @cindex nscd, cache invalidation
  12126. This invalidate the given cache. For instance, running:
  12127. @example
  12128. herd invalidate nscd hosts
  12129. @end example
  12130. @noindent
  12131. invalidates the host name lookup cache of nscd.
  12132. @item statistics
  12133. Running @command{herd statistics nscd} displays information about nscd usage
  12134. and caches.
  12135. @end table
  12136. @end deffn
  12137. @defvr {Scheme Variable} %nscd-default-configuration
  12138. This is the default @code{<nscd-configuration>} value (see below) used
  12139. by @code{nscd-service}. It uses the caches defined by
  12140. @code{%nscd-default-caches}; see below.
  12141. @end defvr
  12142. @deftp {Data Type} nscd-configuration
  12143. This is the data type representing the name service cache daemon (nscd)
  12144. configuration.
  12145. @table @asis
  12146. @item @code{name-services} (default: @code{'()})
  12147. List of packages denoting @dfn{name services} that must be visible to
  12148. the nscd---e.g., @code{(list @var{nss-mdns})}.
  12149. @item @code{glibc} (default: @var{glibc})
  12150. Package object denoting the GNU C Library providing the @command{nscd}
  12151. command.
  12152. @item @code{log-file} (default: @code{"/var/log/nscd.log"})
  12153. Name of the nscd log file. This is where debugging output goes when
  12154. @code{debug-level} is strictly positive.
  12155. @item @code{debug-level} (default: @code{0})
  12156. Integer denoting the debugging levels. Higher numbers mean that more
  12157. debugging output is logged.
  12158. @item @code{caches} (default: @code{%nscd-default-caches})
  12159. List of @code{<nscd-cache>} objects denoting things to be cached; see
  12160. below.
  12161. @end table
  12162. @end deftp
  12163. @deftp {Data Type} nscd-cache
  12164. Data type representing a cache database of nscd and its parameters.
  12165. @table @asis
  12166. @item @code{database}
  12167. This is a symbol representing the name of the database to be cached.
  12168. Valid values are @code{passwd}, @code{group}, @code{hosts}, and
  12169. @code{services}, which designate the corresponding NSS database
  12170. (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
  12171. @item @code{positive-time-to-live}
  12172. @itemx @code{negative-time-to-live} (default: @code{20})
  12173. A number representing the number of seconds during which a positive or
  12174. negative lookup result remains in cache.
  12175. @item @code{check-files?} (default: @code{#t})
  12176. Whether to check for updates of the files corresponding to
  12177. @var{database}.
  12178. For instance, when @var{database} is @code{hosts}, setting this flag
  12179. instructs nscd to check for updates in @file{/etc/hosts} and to take
  12180. them into account.
  12181. @item @code{persistent?} (default: @code{#t})
  12182. Whether the cache should be stored persistently on disk.
  12183. @item @code{shared?} (default: @code{#t})
  12184. Whether the cache should be shared among users.
  12185. @item @code{max-database-size} (default: 32@tie{}MiB)
  12186. Maximum size in bytes of the database cache.
  12187. @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
  12188. @c settings, so leave them out.
  12189. @end table
  12190. @end deftp
  12191. @defvr {Scheme Variable} %nscd-default-caches
  12192. List of @code{<nscd-cache>} objects used by default by
  12193. @code{nscd-configuration} (see above).
  12194. It enables persistent and aggressive caching of service and host name
  12195. lookups. The latter provides better host name lookup performance,
  12196. resilience in the face of unreliable name servers, and also better
  12197. privacy---often the result of host name lookups is in local cache, so
  12198. external name servers do not even need to be queried.
  12199. @end defvr
  12200. @anchor{syslog-configuration-type}
  12201. @cindex syslog
  12202. @cindex logging
  12203. @deftp {Data Type} syslog-configuration
  12204. This data type represents the configuration of the syslog daemon.
  12205. @table @asis
  12206. @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
  12207. The syslog daemon to use.
  12208. @item @code{config-file} (default: @code{%default-syslog.conf})
  12209. The syslog configuration file to use.
  12210. @end table
  12211. @end deftp
  12212. @anchor{syslog-service}
  12213. @cindex syslog
  12214. @deffn {Scheme Procedure} syslog-service @var{config}
  12215. Return a service that runs a syslog daemon according to @var{config}.
  12216. @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
  12217. information on the configuration file syntax.
  12218. @end deffn
  12219. @defvr {Scheme Variable} guix-service-type
  12220. This is the type of the service that runs the build daemon,
  12221. @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
  12222. @code{guix-configuration} record as described below.
  12223. @end defvr
  12224. @anchor{guix-configuration-type}
  12225. @deftp {Data Type} guix-configuration
  12226. This data type represents the configuration of the Guix build daemon.
  12227. @xref{Invoking guix-daemon}, for more information.
  12228. @table @asis
  12229. @item @code{guix} (default: @var{guix})
  12230. The Guix package to use.
  12231. @item @code{build-group} (default: @code{"guixbuild"})
  12232. Name of the group for build user accounts.
  12233. @item @code{build-accounts} (default: @code{10})
  12234. Number of build user accounts to create.
  12235. @item @code{authorize-key?} (default: @code{#t})
  12236. @cindex substitutes, authorization thereof
  12237. Whether to authorize the substitute keys listed in
  12238. @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
  12239. (@pxref{Substitutes}).
  12240. When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
  12241. changed by invoking @command{guix archive --authorize}. You must
  12242. instead adjust @code{guix-configuration} as you wish and reconfigure the
  12243. system. This ensures that your operating system configuration file is
  12244. self-contained.
  12245. @quotation Note
  12246. When booting or reconfiguring to a system where @code{authorize-key?}
  12247. is true, the existing @file{/etc/guix/acl} file is backed up as
  12248. @file{/etc/guix/acl.bak} if it was determined to be a manually modified
  12249. file. This is to facilitate migration from earlier versions, which
  12250. allowed for in-place modifications to @file{/etc/guix/acl}.
  12251. @end quotation
  12252. @vindex %default-authorized-guix-keys
  12253. @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
  12254. The list of authorized key files for archive imports, as a list of
  12255. string-valued gexps (@pxref{Invoking guix archive}). By default, it
  12256. contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
  12257. See @code{substitute-urls} below for an example on how to change it.
  12258. @item @code{use-substitutes?} (default: @code{#t})
  12259. Whether to use substitutes.
  12260. @item @code{substitute-urls} (default: @code{%default-substitute-urls})
  12261. The list of URLs where to look for substitutes by default.
  12262. Suppose you would like to fetch substitutes from @code{guix.example.org}
  12263. in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
  12264. two things: (1) add @code{guix.example.org} to @code{substitute-urls},
  12265. and (2) authorize its signing key, having done appropriate checks
  12266. (@pxref{Substitute Server Authorization}). The configuration below does
  12267. exactly that:
  12268. @lisp
  12269. (guix-configuration
  12270. (substitute-urls
  12271. (append (list "https://guix.example.org")
  12272. %default-substitute-urls))
  12273. (authorized-keys
  12274. (append (list (local-file "./guix.example.org-key.pub"))
  12275. %default-authorized-guix-keys)))
  12276. @end lisp
  12277. This example assumes that the file @file{./guix.example.org-key.pub}
  12278. contains the public key that @code{guix.example.org} uses to sign
  12279. substitutes.
  12280. @item @code{max-silent-time} (default: @code{0})
  12281. @itemx @code{timeout} (default: @code{0})
  12282. The number of seconds of silence and the number of seconds of activity,
  12283. respectively, after which a build process times out. A value of zero
  12284. disables the timeout.
  12285. @item @code{log-compression} (default: @code{'bzip2})
  12286. The type of compression used for build logs---one of @code{gzip},
  12287. @code{bzip2}, or @code{none}.
  12288. @item @code{discover?} (default: @code{#f})
  12289. Whether to discover substitute servers on the local network using mDNS
  12290. and DNS-SD.
  12291. @item @code{extra-options} (default: @code{'()})
  12292. List of extra command-line options for @command{guix-daemon}.
  12293. @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
  12294. File where @command{guix-daemon}'s standard output and standard error
  12295. are written.
  12296. @cindex HTTP proxy, for @code{guix-daemon}
  12297. @cindex proxy, for @code{guix-daemon} HTTP access
  12298. @item @code{http-proxy} (default: @code{#f})
  12299. The URL of the HTTP and HTTPS proxy used for downloading fixed-output
  12300. derivations and substitutes.
  12301. It is also possible to change the daemon's proxy at run time through the
  12302. @code{set-http-proxy} action, which restarts it:
  12303. @example
  12304. herd set-http-proxy guix-daemon http://localhost:8118
  12305. @end example
  12306. To clear the proxy settings, run:
  12307. @example
  12308. herd set-http-proxy guix-daemon
  12309. @end example
  12310. @item @code{tmpdir} (default: @code{#f})
  12311. A directory path where the @command{guix-daemon} will perform builds.
  12312. @end table
  12313. @end deftp
  12314. @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
  12315. Run @var{udev}, which populates the @file{/dev} directory dynamically.
  12316. udev rules can be provided as a list of files through the @var{rules}
  12317. variable. The procedures @code{udev-rule}, @code{udev-rules-service}
  12318. and @code{file->udev-rule} from @code{(gnu services base)} simplify the
  12319. creation of such rule files.
  12320. The @command{herd rules udev} command, as root, returns the name of the
  12321. directory containing all the active udev rules.
  12322. @end deffn
  12323. @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
  12324. Return a udev-rule file named @var{file-name} containing the rules
  12325. defined by the @var{contents} literal.
  12326. In the following example, a rule for a USB device is defined to be
  12327. stored in the file @file{90-usb-thing.rules}. The rule runs a script
  12328. upon detecting a USB device with a given product identifier.
  12329. @lisp
  12330. (define %example-udev-rule
  12331. (udev-rule
  12332. "90-usb-thing.rules"
  12333. (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
  12334. "ATTR@{product@}==\"Example\", "
  12335. "RUN+=\"/path/to/script\"")))
  12336. @end lisp
  12337. @end deffn
  12338. @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
  12339. [#:groups @var{groups}]
  12340. Return a service that extends @code{udev-service-type } with @var{rules}
  12341. and @code{account-service-type} with @var{groups} as system groups.
  12342. This works by creating a singleton service type
  12343. @code{@var{name}-udev-rules}, of which the returned service is an
  12344. instance.
  12345. Here we show how it can be used to extend @code{udev-service-type} with the
  12346. previously defined rule @code{%example-udev-rule}.
  12347. @lisp
  12348. (operating-system
  12349. ;; @dots{}
  12350. (services
  12351. (cons (udev-rules-service 'usb-thing %example-udev-rule)
  12352. %desktop-services)))
  12353. @end lisp
  12354. @end deffn
  12355. @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
  12356. Return a udev file named @var{file-name} containing the rules defined
  12357. within @var{file}, a file-like object.
  12358. The following example showcases how we can use an existing rule file.
  12359. @lisp
  12360. (use-modules (guix download) ;for url-fetch
  12361. (guix packages) ;for origin
  12362. @dots{})
  12363. (define %android-udev-rules
  12364. (file->udev-rule
  12365. "51-android-udev.rules"
  12366. (let ((version "20170910"))
  12367. (origin
  12368. (method url-fetch)
  12369. (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
  12370. "android-udev-rules/" version "/51-android.rules"))
  12371. (sha256
  12372. (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
  12373. @end lisp
  12374. @end deffn
  12375. Additionally, Guix package definitions can be included in @var{rules} in
  12376. order to extend the udev rules with the definitions found under their
  12377. @file{lib/udev/rules.d} sub-directory. In lieu of the previous
  12378. @var{file->udev-rule} example, we could have used the
  12379. @var{android-udev-rules} package which exists in Guix in the @code{(gnu
  12380. packages android)} module.
  12381. The following example shows how to use the @var{android-udev-rules}
  12382. package so that the Android tool @command{adb} can detect devices
  12383. without root privileges. It also details how to create the
  12384. @code{adbusers} group, which is required for the proper functioning of
  12385. the rules defined within the @code{android-udev-rules} package. To
  12386. create such a group, we must define it both as part of the
  12387. @code{supplementary-groups} of our @code{user-account} declaration, as
  12388. well as in the @var{groups} of the @code{udev-rules-service} procedure.
  12389. @lisp
  12390. (use-modules (gnu packages android) ;for android-udev-rules
  12391. (gnu system shadow) ;for user-group
  12392. @dots{})
  12393. (operating-system
  12394. ;; @dots{}
  12395. (users (cons (user-account
  12396. ;; @dots{}
  12397. (supplementary-groups
  12398. '("adbusers" ;for adb
  12399. "wheel" "netdev" "audio" "video")))))
  12400. ;; @dots{}
  12401. (services
  12402. (cons (udev-rules-service 'android android-udev-rules
  12403. #:groups '("adbusers"))
  12404. %desktop-services)))
  12405. @end lisp
  12406. @defvr {Scheme Variable} urandom-seed-service-type
  12407. Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
  12408. when rebooting. It also tries to seed @file{/dev/urandom} from
  12409. @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
  12410. readable.
  12411. @end defvr
  12412. @defvr {Scheme Variable} %random-seed-file
  12413. This is the name of the file where some random bytes are saved by
  12414. @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
  12415. It defaults to @file{/var/lib/random-seed}.
  12416. @end defvr
  12417. @cindex mouse
  12418. @cindex gpm
  12419. @defvr {Scheme Variable} gpm-service-type
  12420. This is the type of the service that runs GPM, the @dfn{general-purpose
  12421. mouse daemon}, which provides mouse support to the Linux console. GPM
  12422. allows users to use the mouse in the console, notably to select, copy,
  12423. and paste text.
  12424. The value for services of this type must be a @code{gpm-configuration}
  12425. (see below). This service is not part of @code{%base-services}.
  12426. @end defvr
  12427. @deftp {Data Type} gpm-configuration
  12428. Data type representing the configuration of GPM.
  12429. @table @asis
  12430. @item @code{options} (default: @code{%default-gpm-options})
  12431. Command-line options passed to @command{gpm}. The default set of
  12432. options instruct @command{gpm} to listen to mouse events on
  12433. @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
  12434. more information.
  12435. @item @code{gpm} (default: @code{gpm})
  12436. The GPM package to use.
  12437. @end table
  12438. @end deftp
  12439. @anchor{guix-publish-service-type}
  12440. @deffn {Scheme Variable} guix-publish-service-type
  12441. This is the service type for @command{guix publish} (@pxref{Invoking
  12442. guix publish}). Its value must be a @code{guix-publish-configuration}
  12443. object, as described below.
  12444. This assumes that @file{/etc/guix} already contains a signing key pair as
  12445. created by @command{guix archive --generate-key} (@pxref{Invoking guix
  12446. archive}). If that is not the case, the service will fail to start.
  12447. @end deffn
  12448. @deftp {Data Type} guix-publish-configuration
  12449. Data type representing the configuration of the @code{guix publish}
  12450. service.
  12451. @table @asis
  12452. @item @code{guix} (default: @code{guix})
  12453. The Guix package to use.
  12454. @item @code{port} (default: @code{80})
  12455. The TCP port to listen for connections.
  12456. @item @code{host} (default: @code{"localhost"})
  12457. The host (and thus, network interface) to listen to. Use
  12458. @code{"0.0.0.0"} to listen on all the network interfaces.
  12459. @item @code{advertise?} (default: @code{#f})
  12460. When true, advertise the service on the local network @i{via} the DNS-SD
  12461. protocol, using Avahi.
  12462. This allows neighboring Guix devices with discovery on (see
  12463. @code{guix-configuration} above) to discover this @command{guix publish}
  12464. instance and to automatically download substitutes from it.
  12465. @item @code{compression} (default: @code{'(("gzip" 3))})
  12466. This is a list of compression method/level tuple used when compressing
  12467. substitutes. For example, to compress all substitutes with @emph{both} lzip
  12468. at level 7 and gzip at level 9, write:
  12469. @lisp
  12470. '(("lzip" 7) ("gzip" 9))
  12471. @end lisp
  12472. Level 9 achieves the best compression ratio at the expense of increased CPU
  12473. usage, whereas level 1 achieves fast compression. @xref{Invoking guix
  12474. publish}, for more information on the available compression methods and
  12475. the tradeoffs involved.
  12476. An empty list disables compression altogether.
  12477. @item @code{nar-path} (default: @code{"nar"})
  12478. The URL path at which ``nars'' can be fetched. @xref{Invoking guix
  12479. publish, @option{--nar-path}}, for details.
  12480. @item @code{cache} (default: @code{#f})
  12481. When it is @code{#f}, disable caching and instead generate archives on
  12482. demand. Otherwise, this should be the name of a directory---e.g.,
  12483. @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
  12484. archives and meta-data ready to be sent. @xref{Invoking guix publish,
  12485. @option{--cache}}, for more information on the tradeoffs involved.
  12486. @item @code{workers} (default: @code{#f})
  12487. When it is an integer, this is the number of worker threads used for
  12488. caching; when @code{#f}, the number of processors is used.
  12489. @xref{Invoking guix publish, @option{--workers}}, for more information.
  12490. @item @code{cache-bypass-threshold} (default: 10 MiB)
  12491. When @code{cache} is true, this is the maximum size in bytes of a store
  12492. item for which @command{guix publish} may bypass its cache in case of a
  12493. cache miss. @xref{Invoking guix publish,
  12494. @option{--cache-bypass-threshold}}, for more information.
  12495. @item @code{ttl} (default: @code{#f})
  12496. When it is an integer, this denotes the @dfn{time-to-live} in seconds
  12497. of the published archives. @xref{Invoking guix publish, @option{--ttl}},
  12498. for more information.
  12499. @end table
  12500. @end deftp
  12501. @anchor{rngd-service}
  12502. @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
  12503. [#:device "/dev/hwrng"]
  12504. Return a service that runs the @command{rngd} program from @var{rng-tools}
  12505. to add @var{device} to the kernel's entropy pool. The service will fail if
  12506. @var{device} does not exist.
  12507. @end deffn
  12508. @anchor{pam-limits-service}
  12509. @cindex session limits
  12510. @cindex ulimit
  12511. @cindex priority
  12512. @cindex realtime
  12513. @cindex jackd
  12514. @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
  12515. Return a service that installs a configuration file for the
  12516. @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
  12517. @code{pam_limits} module}. The procedure optionally takes a list of
  12518. @code{pam-limits-entry} values, which can be used to specify
  12519. @code{ulimit} limits and nice priority limits to user sessions.
  12520. The following limits definition sets two hard and soft limits for all
  12521. login sessions of users in the @code{realtime} group:
  12522. @lisp
  12523. (pam-limits-service
  12524. (list
  12525. (pam-limits-entry "@@realtime" 'both 'rtprio 99)
  12526. (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
  12527. @end lisp
  12528. The first entry increases the maximum realtime priority for
  12529. non-privileged processes; the second entry lifts any restriction of the
  12530. maximum address space that can be locked in memory. These settings are
  12531. commonly used for real-time audio systems.
  12532. @end deffn
  12533. @node Scheduled Job Execution
  12534. @subsection Scheduled Job Execution
  12535. @cindex cron
  12536. @cindex mcron
  12537. @cindex scheduling jobs
  12538. The @code{(gnu services mcron)} module provides an interface to
  12539. GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
  12540. mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
  12541. Unix @command{cron} daemon; the main difference is that it is
  12542. implemented in Guile Scheme, which provides a lot of flexibility when
  12543. specifying the scheduling of jobs and their actions.
  12544. The example below defines an operating system that runs the
  12545. @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
  12546. and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
  12547. well as the @command{mkid} command on behalf of an unprivileged user
  12548. (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
  12549. gexps to introduce job definitions that are passed to mcron
  12550. (@pxref{G-Expressions}).
  12551. @lisp
  12552. (use-modules (guix) (gnu) (gnu services mcron))
  12553. (use-package-modules base idutils)
  12554. (define updatedb-job
  12555. ;; Run 'updatedb' at 3AM every day. Here we write the
  12556. ;; job's action as a Scheme procedure.
  12557. #~(job '(next-hour '(3))
  12558. (lambda ()
  12559. (execl (string-append #$findutils "/bin/updatedb")
  12560. "updatedb"
  12561. "--prunepaths=/tmp /var/tmp /gnu/store"))))
  12562. (define garbage-collector-job
  12563. ;; Collect garbage 5 minutes after midnight every day.
  12564. ;; The job's action is a shell command.
  12565. #~(job "5 0 * * *" ;Vixie cron syntax
  12566. "guix gc -F 1G"))
  12567. (define idutils-job
  12568. ;; Update the index database as user "charlie" at 12:15PM
  12569. ;; and 19:15PM. This runs from the user's home directory.
  12570. #~(job '(next-minute-from (next-hour '(12 19)) '(15))
  12571. (string-append #$idutils "/bin/mkid src")
  12572. #:user "charlie"))
  12573. (operating-system
  12574. ;; @dots{}
  12575. ;; %BASE-SERVICES already includes an instance of
  12576. ;; 'mcron-service-type', which we extend with additional
  12577. ;; jobs using 'simple-service'.
  12578. (services (cons (simple-service 'my-cron-jobs
  12579. mcron-service-type
  12580. (list garbage-collector-job
  12581. updatedb-job
  12582. idutils-job))
  12583. %base-services)))
  12584. @end lisp
  12585. For more complex jobs defined in Scheme where you need control over the top
  12586. level, for instance to introduce a @code{use-modules} form, you can move your
  12587. code to a separate program using the @code{program-file} procedure of the
  12588. @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
  12589. illustrates that.
  12590. @lisp
  12591. (define %battery-alert-job
  12592. ;; Beep when the battery percentage falls below %MIN-LEVEL.
  12593. #~(job
  12594. '(next-minute (range 0 60 1))
  12595. #$(program-file
  12596. "battery-alert.scm"
  12597. (with-imported-modules (source-module-closure
  12598. '((guix build utils)))
  12599. #~(begin
  12600. (use-modules (guix build utils)
  12601. (ice-9 popen)
  12602. (ice-9 regex)
  12603. (ice-9 textual-ports)
  12604. (srfi srfi-2))
  12605. (define %min-level 20)
  12606. (setenv "LC_ALL" "C") ;ensure English output
  12607. (and-let* ((input-pipe (open-pipe*
  12608. OPEN_READ
  12609. #$(file-append acpi "/bin/acpi")))
  12610. (output (get-string-all input-pipe))
  12611. (m (string-match "Discharging, ([0-9]+)%" output))
  12612. (level (string->number (match:substring m 1)))
  12613. ((< level %min-level)))
  12614. (format #t "warning: Battery level is low (~a%)~%" level)
  12615. (invoke #$(file-append beep "/bin/beep") "-r5")))))))
  12616. @end lisp
  12617. @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
  12618. for more information on mcron job specifications. Below is the
  12619. reference of the mcron service.
  12620. On a running system, you can use the @code{schedule} action of the service to
  12621. visualize the mcron jobs that will be executed next:
  12622. @example
  12623. # herd schedule mcron
  12624. @end example
  12625. @noindent
  12626. The example above lists the next five tasks that will be executed, but you can
  12627. also specify the number of tasks to display:
  12628. @example
  12629. # herd schedule mcron 10
  12630. @end example
  12631. @defvr {Scheme Variable} mcron-service-type
  12632. This is the type of the @code{mcron} service, whose value is an
  12633. @code{mcron-configuration} object.
  12634. This service type can be the target of a service extension that provides
  12635. it additional job specifications (@pxref{Service Composition}). In
  12636. other words, it is possible to define services that provide additional
  12637. mcron jobs to run.
  12638. @end defvr
  12639. @deftp {Data Type} mcron-configuration
  12640. Data type representing the configuration of mcron.
  12641. @table @asis
  12642. @item @code{mcron} (default: @var{mcron})
  12643. The mcron package to use.
  12644. @item @code{jobs}
  12645. This is a list of gexps (@pxref{G-Expressions}), where each gexp
  12646. corresponds to an mcron job specification (@pxref{Syntax, mcron job
  12647. specifications,, mcron, GNU@tie{}mcron}).
  12648. @end table
  12649. @end deftp
  12650. @node Log Rotation
  12651. @subsection Log Rotation
  12652. @cindex rottlog
  12653. @cindex log rotation
  12654. @cindex logging
  12655. Log files such as those found in @file{/var/log} tend to grow endlessly,
  12656. so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
  12657. their contents in separate files, possibly compressed. The @code{(gnu
  12658. services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
  12659. log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
  12660. This service is part of @code{%base-services}, and thus enabled by
  12661. default, with the default settings, for commonly encountered log files.
  12662. The example below shows how to extend it with an additional
  12663. @dfn{rotation}, should you need to do that (usually, services that
  12664. produce log files already take care of that):
  12665. @lisp
  12666. (use-modules (guix) (gnu))
  12667. (use-service-modules admin)
  12668. (define my-log-files
  12669. ;; Log files that I want to rotate.
  12670. '("/var/log/something.log" "/var/log/another.log"))
  12671. (operating-system
  12672. ;; @dots{}
  12673. (services (cons (simple-service 'rotate-my-stuff
  12674. rottlog-service-type
  12675. (list (log-rotation
  12676. (frequency 'daily)
  12677. (files my-log-files))))
  12678. %base-services)))
  12679. @end lisp
  12680. @defvr {Scheme Variable} rottlog-service-type
  12681. This is the type of the Rottlog service, whose value is a
  12682. @code{rottlog-configuration} object.
  12683. Other services can extend this one with new @code{log-rotation} objects
  12684. (see below), thereby augmenting the set of files to be rotated.
  12685. This service type can define mcron jobs (@pxref{Scheduled Job
  12686. Execution}) to run the rottlog service.
  12687. @end defvr
  12688. @deftp {Data Type} rottlog-configuration
  12689. Data type representing the configuration of rottlog.
  12690. @table @asis
  12691. @item @code{rottlog} (default: @code{rottlog})
  12692. The Rottlog package to use.
  12693. @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
  12694. The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
  12695. rottlog, GNU Rot[t]log Manual}).
  12696. @item @code{rotations} (default: @code{%default-rotations})
  12697. A list of @code{log-rotation} objects as defined below.
  12698. @item @code{jobs}
  12699. This is a list of gexps where each gexp corresponds to an mcron job
  12700. specification (@pxref{Scheduled Job Execution}).
  12701. @end table
  12702. @end deftp
  12703. @deftp {Data Type} log-rotation
  12704. Data type representing the rotation of a group of log files.
  12705. Taking an example from the Rottlog manual (@pxref{Period Related File
  12706. Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
  12707. defined like this:
  12708. @lisp
  12709. (log-rotation
  12710. (frequency 'daily)
  12711. (files '("/var/log/apache/*"))
  12712. (options '("storedir apache-archives"
  12713. "rotate 6"
  12714. "notifempty"
  12715. "nocompress")))
  12716. @end lisp
  12717. The list of fields is as follows:
  12718. @table @asis
  12719. @item @code{frequency} (default: @code{'weekly})
  12720. The log rotation frequency, a symbol.
  12721. @item @code{files}
  12722. The list of files or file glob patterns to rotate.
  12723. @item @code{options} (default: @code{'()})
  12724. The list of rottlog options for this rotation (@pxref{Configuration
  12725. parameters,,, rottlog, GNU Rot[t]lg Manual}).
  12726. @item @code{post-rotate} (default: @code{#f})
  12727. Either @code{#f} or a gexp to execute once the rotation has completed.
  12728. @end table
  12729. @end deftp
  12730. @defvr {Scheme Variable} %default-rotations
  12731. Specifies weekly rotation of @code{%rotated-files} and of
  12732. @file{/var/log/guix-daemon.log}.
  12733. @end defvr
  12734. @defvr {Scheme Variable} %rotated-files
  12735. The list of syslog-controlled files to be rotated. By default it is:
  12736. @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
  12737. "/var/log/maillog")}.
  12738. @end defvr
  12739. @node Networking Services
  12740. @subsection Networking Services
  12741. The @code{(gnu services networking)} module provides services to configure
  12742. the network interface.
  12743. @cindex DHCP, networking service
  12744. @defvr {Scheme Variable} dhcp-client-service-type
  12745. This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
  12746. Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
  12747. is the DHCP client package to use, @code{isc-dhcp} by default.
  12748. @end defvr
  12749. @deffn {Scheme Procedure} dhcpd-service-type
  12750. This type defines a service that runs a DHCP daemon. To create a
  12751. service of this type, you must supply a @code{<dhcpd-configuration>}.
  12752. For example:
  12753. @lisp
  12754. (service dhcpd-service-type
  12755. (dhcpd-configuration
  12756. (config-file (local-file "my-dhcpd.conf"))
  12757. (interfaces '("enp0s25"))))
  12758. @end lisp
  12759. @end deffn
  12760. @deftp {Data Type} dhcpd-configuration
  12761. @table @asis
  12762. @item @code{package} (default: @code{isc-dhcp})
  12763. The package that provides the DHCP daemon. This package is expected to
  12764. provide the daemon at @file{sbin/dhcpd} relative to its output
  12765. directory. The default package is the
  12766. @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
  12767. @item @code{config-file} (default: @code{#f})
  12768. The configuration file to use. This is required. It will be passed to
  12769. @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
  12770. object (@pxref{G-Expressions, file-like objects}). See @code{man
  12771. dhcpd.conf} for details on the configuration file syntax.
  12772. @item @code{version} (default: @code{"4"})
  12773. The DHCP version to use. The ISC DHCP server supports the values ``4'',
  12774. ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
  12775. options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
  12776. details.
  12777. @item @code{run-directory} (default: @code{"/run/dhcpd"})
  12778. The run directory to use. At service activation time, this directory
  12779. will be created if it does not exist.
  12780. @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
  12781. The PID file to use. This corresponds to the @code{-pf} option of
  12782. @code{dhcpd}. See @code{man dhcpd} for details.
  12783. @item @code{interfaces} (default: @code{'()})
  12784. The names of the network interfaces on which dhcpd should listen for
  12785. broadcasts. If this list is not empty, then its elements (which must be
  12786. strings) will be appended to the @code{dhcpd} invocation when starting
  12787. the daemon. It may not be necessary to explicitly specify any
  12788. interfaces here; see @code{man dhcpd} for details.
  12789. @end table
  12790. @end deftp
  12791. @defvr {Scheme Variable} static-networking-service-type
  12792. This is the type for statically-configured network interfaces.
  12793. @c TODO Document <static-networking> data structures.
  12794. @end defvr
  12795. @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
  12796. [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
  12797. [#:requirement @code{'(udev)}]
  12798. Return a service that starts @var{interface} with address @var{ip}. If
  12799. @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
  12800. it must be a string specifying the default network gateway. @var{requirement}
  12801. can be used to declare a dependency on another service before configuring the
  12802. interface.
  12803. This procedure can be called several times, one for each network
  12804. interface of interest. Behind the scenes what it does is extend
  12805. @code{static-networking-service-type} with additional network interfaces
  12806. to handle.
  12807. For example:
  12808. @lisp
  12809. (static-networking-service "eno1" "192.168.1.82"
  12810. #:gateway "192.168.1.2"
  12811. #:name-servers '("192.168.1.2"))
  12812. @end lisp
  12813. @end deffn
  12814. @cindex wicd
  12815. @cindex wireless
  12816. @cindex WiFi
  12817. @cindex network management
  12818. @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
  12819. Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
  12820. management daemon that aims to simplify wired and wireless networking.
  12821. This service adds the @var{wicd} package to the global profile, providing
  12822. several commands to interact with the daemon and configure networking:
  12823. @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
  12824. and @command{wicd-curses} user interfaces.
  12825. @end deffn
  12826. @cindex ModemManager
  12827. @defvr {Scheme Variable} modem-manager-service-type
  12828. This is the service type for the
  12829. @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
  12830. service. The value for this service type is a
  12831. @code{modem-manager-configuration} record.
  12832. This service is part of @code{%desktop-services} (@pxref{Desktop
  12833. Services}).
  12834. @end defvr
  12835. @deftp {Data Type} modem-manager-configuration
  12836. Data type representing the configuration of ModemManager.
  12837. @table @asis
  12838. @item @code{modem-manager} (default: @code{modem-manager})
  12839. The ModemManager package to use.
  12840. @end table
  12841. @end deftp
  12842. @cindex USB_ModeSwitch
  12843. @cindex Modeswitching
  12844. @defvr {Scheme Variable} usb-modeswitch-service-type
  12845. This is the service type for the
  12846. @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
  12847. service. The value for this service type is
  12848. a @code{usb-modeswitch-configuration} record.
  12849. When plugged in, some USB modems (and other USB devices) initially present
  12850. themselves as a read-only storage medium and not as a modem. They need to be
  12851. @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
  12852. installs udev rules to automatically modeswitch these devices when they are
  12853. plugged in.
  12854. This service is part of @code{%desktop-services} (@pxref{Desktop
  12855. Services}).
  12856. @end defvr
  12857. @deftp {Data Type} usb-modeswitch-configuration
  12858. Data type representing the configuration of USB_ModeSwitch.
  12859. @table @asis
  12860. @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
  12861. The USB_ModeSwitch package providing the binaries for modeswitching.
  12862. @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
  12863. The package providing the device data and udev rules file used by
  12864. USB_ModeSwitch.
  12865. @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
  12866. Which config file to use for the USB_ModeSwitch dispatcher. By default the
  12867. config file shipped with USB_ModeSwitch is used which disables logging to
  12868. @file{/var/log} among other default settings. If set to @code{#f}, no config
  12869. file is used.
  12870. @end table
  12871. @end deftp
  12872. @cindex NetworkManager
  12873. @defvr {Scheme Variable} network-manager-service-type
  12874. This is the service type for the
  12875. @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
  12876. service. The value for this service type is a
  12877. @code{network-manager-configuration} record.
  12878. This service is part of @code{%desktop-services} (@pxref{Desktop
  12879. Services}).
  12880. @end defvr
  12881. @deftp {Data Type} network-manager-configuration
  12882. Data type representing the configuration of NetworkManager.
  12883. @table @asis
  12884. @item @code{network-manager} (default: @code{network-manager})
  12885. The NetworkManager package to use.
  12886. @item @code{dns} (default: @code{"default"})
  12887. Processing mode for DNS, which affects how NetworkManager uses the
  12888. @code{resolv.conf} configuration file.
  12889. @table @samp
  12890. @item default
  12891. NetworkManager will update @code{resolv.conf} to reflect the nameservers
  12892. provided by currently active connections.
  12893. @item dnsmasq
  12894. NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
  12895. @dfn{conditional forwarding} configuration if you are connected to a VPN, and
  12896. then update @code{resolv.conf} to point to the local nameserver.
  12897. With this setting, you can share your network connection. For example when
  12898. you want to share your network connection to another laptop @i{via} an
  12899. Ethernet cable, you can open @command{nm-connection-editor} and configure the
  12900. Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
  12901. and reestablish the connection (or reboot).
  12902. You can also set up a @dfn{host-to-guest connection} to QEMU VMs
  12903. (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
  12904. e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
  12905. browser on your host system, or connect to the VM @i{via} SSH
  12906. (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
  12907. host-to-guest connection, run this command once:
  12908. @example
  12909. nmcli connection add type tun \
  12910. connection.interface-name tap0 \
  12911. tun.mode tap tun.owner $(id -u) \
  12912. ipv4.method shared \
  12913. ipv4.addresses 172.28.112.1/24
  12914. @end example
  12915. Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
  12916. @option{-nic tap,ifname=tap0,script=no,downscript=no} to
  12917. @command{qemu-system-...}.
  12918. @item none
  12919. NetworkManager will not modify @code{resolv.conf}.
  12920. @end table
  12921. @item @code{vpn-plugins} (default: @code{'()})
  12922. This is the list of available plugins for virtual private networks
  12923. (VPNs). An example of this is the @code{network-manager-openvpn}
  12924. package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
  12925. @end table
  12926. @end deftp
  12927. @cindex Connman
  12928. @deffn {Scheme Variable} connman-service-type
  12929. This is the service type to run @url{https://01.org/connman,Connman},
  12930. a network connection manager.
  12931. Its value must be an
  12932. @code{connman-configuration} record as in this example:
  12933. @lisp
  12934. (service connman-service-type
  12935. (connman-configuration
  12936. (disable-vpn? #t)))
  12937. @end lisp
  12938. See below for details about @code{connman-configuration}.
  12939. @end deffn
  12940. @deftp {Data Type} connman-configuration
  12941. Data Type representing the configuration of connman.
  12942. @table @asis
  12943. @item @code{connman} (default: @var{connman})
  12944. The connman package to use.
  12945. @item @code{disable-vpn?} (default: @code{#f})
  12946. When true, disable connman's vpn plugin.
  12947. @end table
  12948. @end deftp
  12949. @cindex WPA Supplicant
  12950. @defvr {Scheme Variable} wpa-supplicant-service-type
  12951. This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
  12952. supplicant}, an authentication daemon required to authenticate against
  12953. encrypted WiFi or ethernet networks.
  12954. @end defvr
  12955. @deftp {Data Type} wpa-supplicant-configuration
  12956. Data type representing the configuration of WPA Supplicant.
  12957. It takes the following parameters:
  12958. @table @asis
  12959. @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
  12960. The WPA Supplicant package to use.
  12961. @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
  12962. List of services that should be started before WPA Supplicant starts.
  12963. @item @code{dbus?} (default: @code{#t})
  12964. Whether to listen for requests on D-Bus.
  12965. @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
  12966. Where to store the PID file.
  12967. @item @code{interface} (default: @code{#f})
  12968. If this is set, it must specify the name of a network interface that
  12969. WPA supplicant will control.
  12970. @item @code{config-file} (default: @code{#f})
  12971. Optional configuration file to use.
  12972. @item @code{extra-options} (default: @code{'()})
  12973. List of additional command-line arguments to pass to the daemon.
  12974. @end table
  12975. @end deftp
  12976. @cindex hostapd service, for Wi-Fi access points
  12977. @cindex Wi-Fi access points, hostapd service
  12978. @defvr {Scheme Variable} hostapd-service-type
  12979. This is the service type to run the @uref{https://w1.fi/hostapd/,
  12980. hostapd} daemon to set up WiFi (IEEE 802.11) access points and
  12981. authentication servers. Its associated value must be a
  12982. @code{hostapd-configuration} as shown below:
  12983. @lisp
  12984. ;; Use wlan1 to run the access point for "My Network".
  12985. (service hostapd-service-type
  12986. (hostapd-configuration
  12987. (interface "wlan1")
  12988. (ssid "My Network")
  12989. (channel 12)))
  12990. @end lisp
  12991. @end defvr
  12992. @deftp {Data Type} hostapd-configuration
  12993. This data type represents the configuration of the hostapd service, with
  12994. the following fields:
  12995. @table @asis
  12996. @item @code{package} (default: @code{hostapd})
  12997. The hostapd package to use.
  12998. @item @code{interface} (default: @code{"wlan0"})
  12999. The network interface to run the WiFi access point.
  13000. @item @code{ssid}
  13001. The SSID (@dfn{service set identifier}), a string that identifies this
  13002. network.
  13003. @item @code{broadcast-ssid?} (default: @code{#t})
  13004. Whether to broadcast this SSID.
  13005. @item @code{channel} (default: @code{1})
  13006. The WiFi channel to use.
  13007. @item @code{driver} (default: @code{"nl80211"})
  13008. The driver interface type. @code{"nl80211"} is used with all Linux
  13009. mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
  13010. RADIUS server that does # not control any wireless/wired driver.
  13011. @item @code{extra-settings} (default: @code{""})
  13012. Extra settings to append as-is to the hostapd configuration file. See
  13013. @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
  13014. configuration file reference.
  13015. @end table
  13016. @end deftp
  13017. @defvr {Scheme Variable} simulated-wifi-service-type
  13018. This is the type of a service to simulate WiFi networking, which can be
  13019. useful in virtual machines for testing purposes. The service loads the
  13020. Linux kernel
  13021. @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
  13022. @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
  13023. network that can be seen on @code{wlan0}, by default.
  13024. The service's value is a @code{hostapd-configuration} record.
  13025. @end defvr
  13026. @cindex iptables
  13027. @defvr {Scheme Variable} iptables-service-type
  13028. This is the service type to set up an iptables configuration. iptables is a
  13029. packet filtering framework supported by the Linux kernel. This service
  13030. supports configuring iptables for both IPv4 and IPv6. A simple example
  13031. configuration rejecting all incoming connections except those to the ssh port
  13032. 22 is shown below.
  13033. @lisp
  13034. (service iptables-service-type
  13035. (iptables-configuration
  13036. (ipv4-rules (plain-file "iptables.rules" "*filter
  13037. :INPUT ACCEPT
  13038. :FORWARD ACCEPT
  13039. :OUTPUT ACCEPT
  13040. -A INPUT -p tcp --dport 22 -j ACCEPT
  13041. -A INPUT -j REJECT --reject-with icmp-port-unreachable
  13042. COMMIT
  13043. "))
  13044. (ipv6-rules (plain-file "ip6tables.rules" "*filter
  13045. :INPUT ACCEPT
  13046. :FORWARD ACCEPT
  13047. :OUTPUT ACCEPT
  13048. -A INPUT -p tcp --dport 22 -j ACCEPT
  13049. -A INPUT -j REJECT --reject-with icmp6-port-unreachable
  13050. COMMIT
  13051. "))))
  13052. @end lisp
  13053. @end defvr
  13054. @deftp {Data Type} iptables-configuration
  13055. The data type representing the configuration of iptables.
  13056. @table @asis
  13057. @item @code{iptables} (default: @code{iptables})
  13058. The iptables package that provides @code{iptables-restore} and
  13059. @code{ip6tables-restore}.
  13060. @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
  13061. The iptables rules to use. It will be passed to @code{iptables-restore}.
  13062. This may be any ``file-like'' object (@pxref{G-Expressions, file-like
  13063. objects}).
  13064. @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
  13065. The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
  13066. This may be any ``file-like'' object (@pxref{G-Expressions, file-like
  13067. objects}).
  13068. @end table
  13069. @end deftp
  13070. @cindex nftables
  13071. @defvr {Scheme Variable} nftables-service-type
  13072. This is the service type to set up a nftables configuration. nftables is a
  13073. netfilter project that aims to replace the existing iptables, ip6tables,
  13074. arptables and ebtables framework. It provides a new packet filtering
  13075. framework, a new user-space utility @command{nft}, and a compatibility layer
  13076. for iptables. This service comes with a default ruleset
  13077. @code{%default-nftables-ruleset} that rejecting all incomming connections
  13078. except those to the ssh port 22. To use it, simply write:
  13079. @lisp
  13080. (service nftables-service-type)
  13081. @end lisp
  13082. @end defvr
  13083. @deftp {Data Type} nftables-configuration
  13084. The data type representing the configuration of nftables.
  13085. @table @asis
  13086. @item @code{package} (default: @code{nftables})
  13087. The nftables package that provides @command{nft}.
  13088. @item @code{ruleset} (default: @code{%default-nftables-ruleset})
  13089. The nftables ruleset to use. This may be any ``file-like'' object
  13090. (@pxref{G-Expressions, file-like objects}).
  13091. @end table
  13092. @end deftp
  13093. @cindex NTP (Network Time Protocol), service
  13094. @cindex ntpd, service for the Network Time Protocol daemon
  13095. @cindex real time clock
  13096. @defvr {Scheme Variable} ntp-service-type
  13097. This is the type of the service running the @uref{https://www.ntp.org,
  13098. Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
  13099. system clock synchronized with that of the specified NTP servers.
  13100. The value of this service is an @code{ntpd-configuration} object, as described
  13101. below.
  13102. @end defvr
  13103. @deftp {Data Type} ntp-configuration
  13104. This is the data type for the NTP service configuration.
  13105. @table @asis
  13106. @item @code{servers} (default: @code{%ntp-servers})
  13107. This is the list of servers (@code{<ntp-server>} records) with which
  13108. @command{ntpd} will be synchronized. See the @code{ntp-server} data type
  13109. definition below.
  13110. @item @code{allow-large-adjustment?} (default: @code{#t})
  13111. This determines whether @command{ntpd} is allowed to make an initial
  13112. adjustment of more than 1,000 seconds.
  13113. @item @code{ntp} (default: @code{ntp})
  13114. The NTP package to use.
  13115. @end table
  13116. @end deftp
  13117. @defvr {Scheme Variable} %ntp-servers
  13118. List of host names used as the default NTP servers. These are servers of the
  13119. @uref{https://www.ntppool.org/en/, NTP Pool Project}.
  13120. @end defvr
  13121. @deftp {Data Type} ntp-server
  13122. The data type representing the configuration of a NTP server.
  13123. @table @asis
  13124. @item @code{type} (default: @code{'server})
  13125. The type of the NTP server, given as a symbol. One of @code{'pool},
  13126. @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
  13127. @item @code{address}
  13128. The address of the server, as a string.
  13129. @item @code{options}
  13130. NTPD options to use with that specific server, given as a list of option names
  13131. and/or of option names and values tuples. The following example define a server
  13132. to use with the options @option{iburst} and @option{prefer}, as well as
  13133. @option{version} 3 and a @option{maxpoll} time of 16 seconds.
  13134. @example
  13135. (ntp-server
  13136. (type 'server)
  13137. (address "some.ntp.server.org")
  13138. (options `(iburst (version 3) (maxpoll 16) prefer))))
  13139. @end example
  13140. @end table
  13141. @end deftp
  13142. @cindex OpenNTPD
  13143. @deffn {Scheme Procedure} openntpd-service-type
  13144. Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
  13145. by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
  13146. clock synchronized with that of the given servers.
  13147. @lisp
  13148. (service
  13149. openntpd-service-type
  13150. (openntpd-configuration
  13151. (listen-on '("127.0.0.1" "::1"))
  13152. (sensor '("udcf0 correction 70000"))
  13153. (constraint-from '("www.gnu.org"))
  13154. (constraints-from '("https://www.google.com/"))))
  13155. @end lisp
  13156. @end deffn
  13157. @defvr {Scheme Variable} %openntpd-servers
  13158. This variable is a list of the server addresses defined in
  13159. @code{%ntp-servers}.
  13160. @end defvr
  13161. @deftp {Data Type} openntpd-configuration
  13162. @table @asis
  13163. @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
  13164. The openntpd executable to use.
  13165. @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
  13166. A list of local IP addresses or hostnames the ntpd daemon should listen on.
  13167. @item @code{query-from} (default: @code{'()})
  13168. A list of local IP address the ntpd daemon should use for outgoing queries.
  13169. @item @code{sensor} (default: @code{'()})
  13170. Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
  13171. will listen to each sensor that actually exists and ignore non-existent ones.
  13172. See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
  13173. information.
  13174. @item @code{server} (default: @code{'()})
  13175. Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
  13176. @item @code{servers} (default: @code{%openntp-servers})
  13177. Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
  13178. @item @code{constraint-from} (default: @code{'()})
  13179. @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
  13180. This time information is not used for precision but acts as an authenticated
  13181. constraint, thereby reducing the impact of unauthenticated NTP
  13182. man-in-the-middle attacks.
  13183. Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
  13184. a constraint.
  13185. @item @code{constraints-from} (default: @code{'()})
  13186. As with constraint from, specify a list of URLs, IP addresses or hostnames of
  13187. HTTPS servers to provide a constraint. Should the hostname resolve to multiple
  13188. IP addresses, @code{ntpd} will calculate a median constraint from all of them.
  13189. @end table
  13190. @end deftp
  13191. @cindex inetd
  13192. @deffn {Scheme variable} inetd-service-type
  13193. This service runs the @command{inetd} (@pxref{inetd invocation,,,
  13194. inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
  13195. connections on internet sockets, and lazily starts the specified server
  13196. program when a connection is made on one of these sockets.
  13197. The value of this service is an @code{inetd-configuration} object. The
  13198. following example configures the @command{inetd} daemon to provide the
  13199. built-in @command{echo} service, as well as an smtp service which
  13200. forwards smtp traffic over ssh to a server @code{smtp-server} behind a
  13201. gateway @code{hostname}:
  13202. @lisp
  13203. (service
  13204. inetd-service-type
  13205. (inetd-configuration
  13206. (entries (list
  13207. (inetd-entry
  13208. (name "echo")
  13209. (socket-type 'stream)
  13210. (protocol "tcp")
  13211. (wait? #f)
  13212. (user "root"))
  13213. (inetd-entry
  13214. (node "127.0.0.1")
  13215. (name "smtp")
  13216. (socket-type 'stream)
  13217. (protocol "tcp")
  13218. (wait? #f)
  13219. (user "root")
  13220. (program (file-append openssh "/bin/ssh"))
  13221. (arguments
  13222. '("ssh" "-qT" "-i" "/path/to/ssh_key"
  13223. "-W" "smtp-server:25" "user@@hostname")))))))
  13224. @end lisp
  13225. See below for more details about @code{inetd-configuration}.
  13226. @end deffn
  13227. @deftp {Data Type} inetd-configuration
  13228. Data type representing the configuration of @command{inetd}.
  13229. @table @asis
  13230. @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
  13231. The @command{inetd} executable to use.
  13232. @item @code{entries} (default: @code{'()})
  13233. A list of @command{inetd} service entries. Each entry should be created
  13234. by the @code{inetd-entry} constructor.
  13235. @end table
  13236. @end deftp
  13237. @deftp {Data Type} inetd-entry
  13238. Data type representing an entry in the @command{inetd} configuration.
  13239. Each entry corresponds to a socket where @command{inetd} will listen for
  13240. requests.
  13241. @table @asis
  13242. @item @code{node} (default: @code{#f})
  13243. Optional string, a comma-separated list of local addresses
  13244. @command{inetd} should use when listening for this service.
  13245. @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
  13246. description of all options.
  13247. @item @code{name}
  13248. A string, the name must correspond to an entry in @code{/etc/services}.
  13249. @item @code{socket-type}
  13250. One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
  13251. @code{'seqpacket}.
  13252. @item @code{protocol}
  13253. A string, must correspond to an entry in @code{/etc/protocols}.
  13254. @item @code{wait?} (default: @code{#t})
  13255. Whether @command{inetd} should wait for the server to exit before
  13256. listening to new service requests.
  13257. @item @code{user}
  13258. A string containing the user (and, optionally, group) name of the user
  13259. as whom the server should run. The group name can be specified in a
  13260. suffix, separated by a colon or period, i.e.@: @code{"user"},
  13261. @code{"user:group"} or @code{"user.group"}.
  13262. @item @code{program} (default: @code{"internal"})
  13263. The server program which will serve the requests, or @code{"internal"}
  13264. if @command{inetd} should use a built-in service.
  13265. @item @code{arguments} (default: @code{'()})
  13266. A list strings or file-like objects, which are the server program's
  13267. arguments, starting with the zeroth argument, i.e.@: the name of the
  13268. program itself. For @command{inetd}'s internal services, this entry
  13269. must be @code{'()} or @code{'("internal")}.
  13270. @end table
  13271. @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
  13272. detailed discussion of each configuration field.
  13273. @end deftp
  13274. @cindex Tor
  13275. @defvr {Scheme Variable} tor-service-type
  13276. This is the type for a service that runs the @uref{https://torproject.org,
  13277. Tor} anonymous networking daemon. The service is configured using a
  13278. @code{<tor-configuration>} record. By default, the Tor daemon runs as the
  13279. @code{tor} unprivileged user, which is a member of the @code{tor} group.
  13280. @end defvr
  13281. @deftp {Data Type} tor-configuration
  13282. @table @asis
  13283. @item @code{tor} (default: @code{tor})
  13284. The package that provides the Tor daemon. This package is expected to provide
  13285. the daemon at @file{bin/tor} relative to its output directory. The default
  13286. package is the @uref{https://www.torproject.org, Tor Project's}
  13287. implementation.
  13288. @item @code{config-file} (default: @code{(plain-file "empty" "")})
  13289. The configuration file to use. It will be appended to a default configuration
  13290. file, and the final configuration file will be passed to @code{tor} via its
  13291. @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
  13292. file-like objects}). See @code{man tor} for details on the configuration file
  13293. syntax.
  13294. @item @code{hidden-services} (default: @code{'()})
  13295. The list of @code{<hidden-service>} records to use. For any hidden service
  13296. you include in this list, appropriate configuration to enable the hidden
  13297. service will be automatically added to the default configuration file. You
  13298. may conveniently create @code{<hidden-service>} records using the
  13299. @code{tor-hidden-service} procedure described below.
  13300. @item @code{socks-socket-type} (default: @code{'tcp})
  13301. The default socket type that Tor should use for its SOCKS socket. This must
  13302. be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
  13303. Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
  13304. If it is @code{'unix}, then Tor will listen on the UNIX domain socket
  13305. @file{/var/run/tor/socks-sock}, which will be made writable by members of the
  13306. @code{tor} group.
  13307. If you want to customize the SOCKS socket in more detail, leave
  13308. @code{socks-socket-type} at its default value of @code{'tcp} and use
  13309. @code{config-file} to override the default by providing your own
  13310. @code{SocksPort} option.
  13311. @end table
  13312. @end deftp
  13313. @cindex hidden service
  13314. @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
  13315. Define a new Tor @dfn{hidden service} called @var{name} and implementing
  13316. @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
  13317. @example
  13318. '((22 "127.0.0.1:22")
  13319. (80 "127.0.0.1:8080"))
  13320. @end example
  13321. In this example, port 22 of the hidden service is mapped to local port 22, and
  13322. port 80 is mapped to local port 8080.
  13323. This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
  13324. the @file{hostname} file contains the @code{.onion} host name for the hidden
  13325. service.
  13326. See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
  13327. project's documentation} for more information.
  13328. @end deffn
  13329. The @code{(gnu services rsync)} module provides the following services:
  13330. You might want an rsync daemon if you have files that you want available
  13331. so anyone (or just yourself) can download existing files or upload new
  13332. files.
  13333. @deffn {Scheme Variable} rsync-service-type
  13334. This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
  13335. The value for this service type is a
  13336. @command{rsync-configuration} record as in this example:
  13337. @lisp
  13338. (service rsync-service-type)
  13339. @end lisp
  13340. See below for details about @code{rsync-configuration}.
  13341. @end deffn
  13342. @deftp {Data Type} rsync-configuration
  13343. Data type representing the configuration for @code{rsync-service}.
  13344. @table @asis
  13345. @item @code{package} (default: @var{rsync})
  13346. @code{rsync} package to use.
  13347. @item @code{port-number} (default: @code{873})
  13348. TCP port on which @command{rsync} listens for incoming connections. If port
  13349. is less than @code{1024} @command{rsync} needs to be started as the
  13350. @code{root} user and group.
  13351. @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
  13352. Name of the file where @command{rsync} writes its PID.
  13353. @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
  13354. Name of the file where @command{rsync} writes its lock file.
  13355. @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
  13356. Name of the file where @command{rsync} writes its log file.
  13357. @item @code{use-chroot?} (default: @var{#t})
  13358. Whether to use chroot for @command{rsync} shared directory.
  13359. @item @code{share-path} (default: @file{/srv/rsync})
  13360. Location of the @command{rsync} shared directory.
  13361. @item @code{share-comment} (default: @code{"Rsync share"})
  13362. Comment of the @command{rsync} shared directory.
  13363. @item @code{read-only?} (default: @var{#f})
  13364. Read-write permissions to shared directory.
  13365. @item @code{timeout} (default: @code{300})
  13366. I/O timeout in seconds.
  13367. @item @code{user} (default: @var{"root"})
  13368. Owner of the @code{rsync} process.
  13369. @item @code{group} (default: @var{"root"})
  13370. Group of the @code{rsync} process.
  13371. @item @code{uid} (default: @var{"rsyncd"})
  13372. User name or user ID that file transfers to and from that module should take
  13373. place as when the daemon was run as @code{root}.
  13374. @item @code{gid} (default: @var{"rsyncd"})
  13375. Group name or group ID that will be used when accessing the module.
  13376. @end table
  13377. @end deftp
  13378. The @code{(gnu services syncthing)} module provides the following services:
  13379. @cindex syncthing
  13380. You might want a syncthing daemon if you have files between two or more
  13381. computers and want to sync them in real time, safely protected from
  13382. prying eyes.
  13383. @deffn {Scheme Variable} syncthing-service-type
  13384. This is the service type for the @uref{https://syncthing.net/,
  13385. syncthing} daemon, The value for this service type is a
  13386. @command{syncthing-configuration} record as in this example:
  13387. @lisp
  13388. (service syncthing-service-type
  13389. (syncthing-configuration (user "alice")))
  13390. @end lisp
  13391. See below for details about @code{syncthing-configuration}.
  13392. @deftp {Data Type} syncthing-configuration
  13393. Data type representing the configuration for @code{syncthing-service-type}.
  13394. @table @asis
  13395. @item @code{syncthing} (default: @var{syncthing})
  13396. @code{syncthing} package to use.
  13397. @item @code{arguments} (default: @var{'()})
  13398. List of command-line arguments passing to @code{syncthing} binary.
  13399. @item @code{logflags} (default: @var{0})
  13400. Sum of loging flags, see
  13401. @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
  13402. @item @code{user} (default: @var{#f})
  13403. The user as which the Syncthing service is to be run.
  13404. This assumes that the specified user exists.
  13405. @item @code{group} (default: @var{"users"})
  13406. The group as which the Syncthing service is to be run.
  13407. This assumes that the specified group exists.
  13408. @item @code{home} (default: @var{#f})
  13409. Common configuration and data directory. The default configuration
  13410. directory is @file{$HOME} of the specified Syncthing @code{user}.
  13411. @end table
  13412. @end deftp
  13413. @end deffn
  13414. Furthermore, @code{(gnu services ssh)} provides the following services.
  13415. @cindex SSH
  13416. @cindex SSH server
  13417. @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
  13418. [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
  13419. [#:allow-empty-passwords? #f] [#:root-login? #f] @
  13420. [#:syslog-output? #t] [#:x11-forwarding? #t] @
  13421. [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
  13422. [#:public-key-authentication? #t] [#:initialize? #t]
  13423. Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
  13424. @var{host-key} must designate a file containing the host key, and readable
  13425. only by root.
  13426. When @var{daemonic?} is true, @command{lshd} will detach from the
  13427. controlling terminal and log its output to syslogd, unless one sets
  13428. @var{syslog-output?} to false. Obviously, it also makes lsh-service
  13429. depend on existence of syslogd service. When @var{pid-file?} is true,
  13430. @command{lshd} writes its PID to the file called @var{pid-file}.
  13431. When @var{initialize?} is true, automatically create the seed and host key
  13432. upon service activation if they do not exist yet. This may take long and
  13433. require interaction.
  13434. When @var{initialize?} is false, it is up to the user to initialize the
  13435. randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
  13436. a key pair with the private key stored in file @var{host-key} (@pxref{lshd
  13437. basics,,, lsh, LSH Manual}).
  13438. When @var{interfaces} is empty, lshd listens for connections on all the
  13439. network interfaces; otherwise, @var{interfaces} must be a list of host names
  13440. or addresses.
  13441. @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
  13442. passwords, and @var{root-login?} specifies whether to accept log-ins as
  13443. root.
  13444. The other options should be self-descriptive.
  13445. @end deffn
  13446. @cindex SSH
  13447. @cindex SSH server
  13448. @deffn {Scheme Variable} openssh-service-type
  13449. This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
  13450. shell daemon, @command{sshd}. Its value must be an
  13451. @code{openssh-configuration} record as in this example:
  13452. @lisp
  13453. (service openssh-service-type
  13454. (openssh-configuration
  13455. (x11-forwarding? #t)
  13456. (permit-root-login 'without-password)
  13457. (authorized-keys
  13458. `(("alice" ,(local-file "alice.pub"))
  13459. ("bob" ,(local-file "bob.pub"))))))
  13460. @end lisp
  13461. See below for details about @code{openssh-configuration}.
  13462. This service can be extended with extra authorized keys, as in this
  13463. example:
  13464. @lisp
  13465. (service-extension openssh-service-type
  13466. (const `(("charlie"
  13467. ,(local-file "charlie.pub")))))
  13468. @end lisp
  13469. @end deffn
  13470. @deftp {Data Type} openssh-configuration
  13471. This is the configuration record for OpenSSH's @command{sshd}.
  13472. @table @asis
  13473. @item @code{openssh} (default @var{openssh})
  13474. The Openssh package to use.
  13475. @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
  13476. Name of the file where @command{sshd} writes its PID.
  13477. @item @code{port-number} (default: @code{22})
  13478. TCP port on which @command{sshd} listens for incoming connections.
  13479. @item @code{permit-root-login} (default: @code{#f})
  13480. This field determines whether and when to allow logins as root. If
  13481. @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
  13482. If it's the symbol @code{'without-password}, then root logins are
  13483. permitted but not with password-based authentication.
  13484. @item @code{allow-empty-passwords?} (default: @code{#f})
  13485. When true, users with empty passwords may log in. When false, they may
  13486. not.
  13487. @item @code{password-authentication?} (default: @code{#t})
  13488. When true, users may log in with their password. When false, they have
  13489. other authentication methods.
  13490. @item @code{public-key-authentication?} (default: @code{#t})
  13491. When true, users may log in using public key authentication. When
  13492. false, users have to use other authentication method.
  13493. Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
  13494. This is used only by protocol version 2.
  13495. @item @code{x11-forwarding?} (default: @code{#f})
  13496. When true, forwarding of X11 graphical client connections is
  13497. enabled---in other words, @command{ssh} options @option{-X} and
  13498. @option{-Y} will work.
  13499. @item @code{allow-agent-forwarding?} (default: @code{#t})
  13500. Whether to allow agent forwarding.
  13501. @item @code{allow-tcp-forwarding?} (default: @code{#t})
  13502. Whether to allow TCP forwarding.
  13503. @item @code{gateway-ports?} (default: @code{#f})
  13504. Whether to allow gateway ports.
  13505. @item @code{challenge-response-authentication?} (default: @code{#f})
  13506. Specifies whether challenge response authentication is allowed (e.g.@: via
  13507. PAM).
  13508. @item @code{use-pam?} (default: @code{#t})
  13509. Enables the Pluggable Authentication Module interface. If set to
  13510. @code{#t}, this will enable PAM authentication using
  13511. @code{challenge-response-authentication?} and
  13512. @code{password-authentication?}, in addition to PAM account and session
  13513. module processing for all authentication types.
  13514. Because PAM challenge response authentication usually serves an
  13515. equivalent role to password authentication, you should disable either
  13516. @code{challenge-response-authentication?} or
  13517. @code{password-authentication?}.
  13518. @item @code{print-last-log?} (default: @code{#t})
  13519. Specifies whether @command{sshd} should print the date and time of the
  13520. last user login when a user logs in interactively.
  13521. @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
  13522. Configures external subsystems (e.g.@: file transfer daemon).
  13523. This is a list of two-element lists, each of which containing the
  13524. subsystem name and a command (with optional arguments) to execute upon
  13525. subsystem request.
  13526. The command @command{internal-sftp} implements an in-process SFTP
  13527. server. Alternatively, one can specify the @command{sftp-server} command:
  13528. @lisp
  13529. (service openssh-service-type
  13530. (openssh-configuration
  13531. (subsystems
  13532. `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
  13533. @end lisp
  13534. @item @code{accepted-environment} (default: @code{'()})
  13535. List of strings describing which environment variables may be exported.
  13536. Each string gets on its own line. See the @code{AcceptEnv} option in
  13537. @code{man sshd_config}.
  13538. This example allows ssh-clients to export the @env{COLORTERM} variable.
  13539. It is set by terminal emulators, which support colors. You can use it in
  13540. your shell's resource file to enable colors for the prompt and commands
  13541. if this variable is set.
  13542. @lisp
  13543. (service openssh-service-type
  13544. (openssh-configuration
  13545. (accepted-environment '("COLORTERM"))))
  13546. @end lisp
  13547. @item @code{authorized-keys} (default: @code{'()})
  13548. @cindex authorized keys, SSH
  13549. @cindex SSH authorized keys
  13550. This is the list of authorized keys. Each element of the list is a user
  13551. name followed by one or more file-like objects that represent SSH public
  13552. keys. For example:
  13553. @lisp
  13554. (openssh-configuration
  13555. (authorized-keys
  13556. `(("rekado" ,(local-file "rekado.pub"))
  13557. ("chris" ,(local-file "chris.pub"))
  13558. ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
  13559. @end lisp
  13560. @noindent
  13561. registers the specified public keys for user accounts @code{rekado},
  13562. @code{chris}, and @code{root}.
  13563. Additional authorized keys can be specified @i{via}
  13564. @code{service-extension}.
  13565. Note that this does @emph{not} interfere with the use of
  13566. @file{~/.ssh/authorized_keys}.
  13567. @item @code{log-level} (default: @code{'info})
  13568. This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
  13569. @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
  13570. page for @file{sshd_config} for the full list of level names.
  13571. @item @code{extra-content} (default: @code{""})
  13572. This field can be used to append arbitrary text to the configuration file. It
  13573. is especially useful for elaborate configurations that cannot be expressed
  13574. otherwise. This configuration, for example, would generally disable root
  13575. logins, but permit them from one specific IP address:
  13576. @lisp
  13577. (openssh-configuration
  13578. (extra-content "\
  13579. Match Address 192.168.0.1
  13580. PermitRootLogin yes"))
  13581. @end lisp
  13582. @end table
  13583. @end deftp
  13584. @deffn {Scheme Procedure} dropbear-service [@var{config}]
  13585. Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
  13586. daemon} with the given @var{config}, a @code{<dropbear-configuration>}
  13587. object.
  13588. For example, to specify a Dropbear service listening on port 1234, add
  13589. this call to the operating system's @code{services} field:
  13590. @lisp
  13591. (dropbear-service (dropbear-configuration
  13592. (port-number 1234)))
  13593. @end lisp
  13594. @end deffn
  13595. @deftp {Data Type} dropbear-configuration
  13596. This data type represents the configuration of a Dropbear SSH daemon.
  13597. @table @asis
  13598. @item @code{dropbear} (default: @var{dropbear})
  13599. The Dropbear package to use.
  13600. @item @code{port-number} (default: 22)
  13601. The TCP port where the daemon waits for incoming connections.
  13602. @item @code{syslog-output?} (default: @code{#t})
  13603. Whether to enable syslog output.
  13604. @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
  13605. File name of the daemon's PID file.
  13606. @item @code{root-login?} (default: @code{#f})
  13607. Whether to allow @code{root} logins.
  13608. @item @code{allow-empty-passwords?} (default: @code{#f})
  13609. Whether to allow empty passwords.
  13610. @item @code{password-authentication?} (default: @code{#t})
  13611. Whether to enable password-based authentication.
  13612. @end table
  13613. @end deftp
  13614. @cindex AutoSSH
  13615. @deffn {Scheme Variable} autossh-service-type
  13616. This is the type for the @uref{https://www.harding.motd.ca/autossh,
  13617. AutoSSH} program that runs a copy of @command{ssh} and monitors it,
  13618. restarting it as necessary should it die or stop passing traffic.
  13619. AutoSSH can be run manually from the command-line by passing arguments
  13620. to the binary @command{autossh} from the package @code{autossh}, but it
  13621. can also be run as a Guix service. This latter use case is documented
  13622. here.
  13623. AutoSSH can be used to forward local traffic to a remote machine using
  13624. an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
  13625. is run as.
  13626. For example, to specify a service running autossh as the user
  13627. @code{pino} and forwarding all local connections to port @code{8081} to
  13628. @code{remote:8081} using an SSH tunnel, add this call to the operating
  13629. system's @code{services} field:
  13630. @lisp
  13631. (service autossh-service-type
  13632. (autossh-configuration
  13633. (user "pino")
  13634. (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
  13635. @end lisp
  13636. @end deffn
  13637. @deftp {Data Type} autossh-configuration
  13638. This data type represents the configuration of an AutoSSH service.
  13639. @table @asis
  13640. @item @code{user} (default @code{"autossh"})
  13641. The user as which the AutoSSH service is to be run.
  13642. This assumes that the specified user exists.
  13643. @item @code{poll} (default @code{600})
  13644. Specifies the connection poll time in seconds.
  13645. @item @code{first-poll} (default @code{#f})
  13646. Specifies how many seconds AutoSSH waits before the first connection
  13647. test. After this first test, polling is resumed at the pace defined in
  13648. @code{poll}. When set to @code{#f}, the first poll is not treated
  13649. specially and will also use the connection poll specified in
  13650. @code{poll}.
  13651. @item @code{gate-time} (default @code{30})
  13652. Specifies how many seconds an SSH connection must be active before it is
  13653. considered successful.
  13654. @item @code{log-level} (default @code{1})
  13655. The log level, corresponding to the levels used by syslog---so @code{0}
  13656. is the most silent while @code{7} is the chattiest.
  13657. @item @code{max-start} (default @code{#f})
  13658. The maximum number of times SSH may be (re)started before AutoSSH exits.
  13659. When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
  13660. @item @code{message} (default @code{""})
  13661. The message to append to the echo message sent when testing connections.
  13662. @item @code{port} (default @code{"0"})
  13663. The ports used for monitoring the connection. When set to @code{"0"},
  13664. monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
  13665. a positive integer, ports @var{n} and @var{n}+1 are used for
  13666. monitoring the connection, such that port @var{n} is the base
  13667. monitoring port and @code{n+1} is the echo port. When set to
  13668. @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
  13669. integers, the ports @var{n} and @var{m} are used for monitoring the
  13670. connection, such that port @var{n} is the base monitoring port and
  13671. @var{m} is the echo port.
  13672. @item @code{ssh-options} (default @code{'()})
  13673. The list of command-line arguments to pass to @command{ssh} when it is
  13674. run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
  13675. may cause undefined behaviour.
  13676. @end table
  13677. @end deftp
  13678. @cindex WebSSH
  13679. @deffn {Scheme Variable} webssh-service-type
  13680. This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
  13681. program that runs a web SSH client. WebSSH can be run manually from the
  13682. command-line by passing arguments to the binary @command{wssh} from the
  13683. package @code{webssh}, but it can also be run as a Guix service. This
  13684. latter use case is documented here.
  13685. For example, to specify a service running WebSSH on loopback interface
  13686. on port @code{8888} with reject policy with a list of allowed to
  13687. connection hosts, and NGINX as a reverse-proxy to this service listening
  13688. for HTTPS connection, add this call to the operating system's
  13689. @code{services} field:
  13690. @lisp
  13691. (service webssh-service-type
  13692. (webssh-configuration (address "127.0.0.1")
  13693. (port 8888)
  13694. (policy 'reject)
  13695. (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
  13696. "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
  13697. (service nginx-service-type
  13698. (nginx-configuration
  13699. (server-blocks
  13700. (list
  13701. (nginx-server-configuration
  13702. (inherit %webssh-configuration-nginx)
  13703. (server-name '("webssh.example.com"))
  13704. (listen '("443 ssl"))
  13705. (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
  13706. (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
  13707. (locations
  13708. (cons (nginx-location-configuration
  13709. (uri "/.well-known")
  13710. (body '("root /var/www;")))
  13711. (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
  13712. @end lisp
  13713. @end deffn
  13714. @deftp {Data Type} webssh-configuration
  13715. Data type representing the configuration for @code{webssh-service}.
  13716. @table @asis
  13717. @item @code{package} (default: @var{webssh})
  13718. @code{webssh} package to use.
  13719. @item @code{user-name} (default: @var{"webssh"})
  13720. User name or user ID that file transfers to and from that module should take
  13721. place.
  13722. @item @code{group-name} (default: @var{"webssh"})
  13723. Group name or group ID that will be used when accessing the module.
  13724. @item @code{address} (default: @var{#f})
  13725. IP address on which @command{webssh} listens for incoming connections.
  13726. @item @code{port} (default: @var{8888})
  13727. TCP port on which @command{webssh} listens for incoming connections.
  13728. @item @code{policy} (default: @var{#f})
  13729. Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
  13730. @item @code{known-hosts} (default: @var{'()})
  13731. List of hosts which allowed for SSH connection from @command{webssh}.
  13732. @item @code{log-file} (default: @file{"/var/log/webssh.log"})
  13733. Name of the file where @command{webssh} writes its log file.
  13734. @item @code{log-level} (default: @var{#f})
  13735. Logging level.
  13736. @end table
  13737. @end deftp
  13738. @defvr {Scheme Variable} %facebook-host-aliases
  13739. This variable contains a string for use in @file{/etc/hosts}
  13740. (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
  13741. line contains a entry that maps a known server name of the Facebook
  13742. on-line service---e.g., @code{www.facebook.com}---to the local
  13743. host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
  13744. This variable is typically used in the @code{hosts-file} field of an
  13745. @code{operating-system} declaration (@pxref{operating-system Reference,
  13746. @file{/etc/hosts}}):
  13747. @lisp
  13748. (use-modules (gnu) (guix))
  13749. (operating-system
  13750. (host-name "mymachine")
  13751. ;; ...
  13752. (hosts-file
  13753. ;; Create a /etc/hosts file with aliases for "localhost"
  13754. ;; and "mymachine", as well as for Facebook servers.
  13755. (plain-file "hosts"
  13756. (string-append (local-host-aliases host-name)
  13757. %facebook-host-aliases))))
  13758. @end lisp
  13759. This mechanism can prevent programs running locally, such as Web
  13760. browsers, from accessing Facebook.
  13761. @end defvr
  13762. The @code{(gnu services avahi)} provides the following definition.
  13763. @defvr {Scheme Variable} avahi-service-type
  13764. This is the service that runs @command{avahi-daemon}, a system-wide
  13765. mDNS/DNS-SD responder that allows for service discovery and
  13766. ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
  13767. Its value must be an @code{avahi-configuration} record---see below.
  13768. This service extends the name service cache daemon (nscd) so that it can
  13769. resolve @code{.local} host names using
  13770. @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
  13771. Service Switch}, for information on host name resolution.
  13772. Additionally, add the @var{avahi} package to the system profile so that
  13773. commands such as @command{avahi-browse} are directly usable.
  13774. @end defvr
  13775. @deftp {Data Type} avahi-configuration
  13776. Data type representation the configuration for Avahi.
  13777. @table @asis
  13778. @item @code{host-name} (default: @code{#f})
  13779. If different from @code{#f}, use that as the host name to
  13780. publish for this machine; otherwise, use the machine's actual host name.
  13781. @item @code{publish?} (default: @code{#t})
  13782. When true, allow host names and services to be published (broadcast) over the
  13783. network.
  13784. @item @code{publish-workstation?} (default: @code{#t})
  13785. When true, @command{avahi-daemon} publishes the machine's host name and IP
  13786. address via mDNS on the local network. To view the host names published on
  13787. your local network, you can run:
  13788. @example
  13789. avahi-browse _workstation._tcp
  13790. @end example
  13791. @item @code{wide-area?} (default: @code{#f})
  13792. When true, DNS-SD over unicast DNS is enabled.
  13793. @item @code{ipv4?} (default: @code{#t})
  13794. @itemx @code{ipv6?} (default: @code{#t})
  13795. These fields determine whether to use IPv4/IPv6 sockets.
  13796. @item @code{domains-to-browse} (default: @code{'()})
  13797. This is a list of domains to browse.
  13798. @end table
  13799. @end deftp
  13800. @deffn {Scheme Variable} openvswitch-service-type
  13801. This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
  13802. service, whose value should be an @code{openvswitch-configuration}
  13803. object.
  13804. @end deffn
  13805. @deftp {Data Type} openvswitch-configuration
  13806. Data type representing the configuration of Open vSwitch, a multilayer
  13807. virtual switch which is designed to enable massive network automation
  13808. through programmatic extension.
  13809. @table @asis
  13810. @item @code{package} (default: @var{openvswitch})
  13811. Package object of the Open vSwitch.
  13812. @end table
  13813. @end deftp
  13814. @defvr {Scheme Variable} pagekite-service-type
  13815. This is the service type for the @uref{https://pagekite.net, PageKite} service,
  13816. a tunneling solution for making localhost servers publicly visible, even from
  13817. behind restrictive firewalls or NAT without forwarded ports. The value for
  13818. this service type is a @code{pagekite-configuration} record.
  13819. Here's an example exposing the local HTTP and SSH daemons:
  13820. @lisp
  13821. (service pagekite-service-type
  13822. (pagekite-configuration
  13823. (kites '("http:@@kitename:localhost:80:@@kitesecret"
  13824. "raw/22:@@kitename:localhost:22:@@kitesecret"))
  13825. (extra-file "/etc/pagekite.rc")))
  13826. @end lisp
  13827. @end defvr
  13828. @deftp {Data Type} pagekite-configuration
  13829. Data type representing the configuration of PageKite.
  13830. @table @asis
  13831. @item @code{package} (default: @var{pagekite})
  13832. Package object of PageKite.
  13833. @item @code{kitename} (default: @code{#f})
  13834. PageKite name for authenticating to the frontend server.
  13835. @item @code{kitesecret} (default: @code{#f})
  13836. Shared secret for authenticating to the frontend server. You should probably
  13837. put this inside @code{extra-file} instead.
  13838. @item @code{frontend} (default: @code{#f})
  13839. Connect to the named PageKite frontend server instead of the
  13840. @uref{https://pagekite.net,,pagekite.net} service.
  13841. @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
  13842. List of service kites to use. Exposes HTTP on port 80 by default. The format
  13843. is @code{proto:kitename:host:port:secret}.
  13844. @item @code{extra-file} (default: @code{#f})
  13845. Extra configuration file to read, which you are expected to create manually.
  13846. Use this to add additional options and manage shared secrets out-of-band.
  13847. @end table
  13848. @end deftp
  13849. @defvr {Scheme Variable} yggdrasil-service-type
  13850. The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
  13851. Yggdrasil network}, an early-stage implementation of a fully end-to-end
  13852. encrypted IPv6 network.
  13853. @quotation
  13854. Yggdrasil provides name-independent routing with cryptographically generated
  13855. addresses. Static addressing means you can keep the same address as long as
  13856. you want, even if you move to a new location, or generate a new address (by
  13857. generating new keys) whenever you want.
  13858. @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
  13859. @end quotation
  13860. Pass it a value of @code{yggdrasil-configuration} to connect it to public
  13861. peers and/or local peers.
  13862. Here is an example using public peers and a static address. The static
  13863. signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
  13864. (the default value for @code{config-file}).
  13865. @lisp
  13866. ;; part of the operating-system declaration
  13867. (service yggdrasil-service-type
  13868. (yggdrasil-configuration
  13869. (autoconf? #f) ;; use only the public peers
  13870. (json-config
  13871. ;; choose one from
  13872. ;; https://github.com/yggdrasil-network/public-peers
  13873. '((peers . #("tcp://1.2.3.4:1337"))))
  13874. ;; /etc/yggdrasil-private.conf is the default value for config-file
  13875. ))
  13876. @end lisp
  13877. @example
  13878. # sample content for /etc/yggdrasil-private.conf
  13879. @{
  13880. # Your public encryption key. Your peers may ask you for this to put
  13881. # into their AllowedEncryptionPublicKeys configuration.
  13882. EncryptionPublicKey: 378dc5...
  13883. # Your private encryption key. DO NOT share this with anyone!
  13884. EncryptionPrivateKey: 0777...
  13885. # Your public signing key. You should not ordinarily need to share
  13886. # this with anyone.
  13887. SigningPublicKey: e1664...
  13888. # Your private signing key. DO NOT share this with anyone!
  13889. SigningPrivateKey: 0589d...
  13890. @}
  13891. @end example
  13892. @end defvr
  13893. @deftp {Data Type} yggdrasil-configuration
  13894. Data type representing the configuration of Yggdrasil.
  13895. @table @asis
  13896. @item @code{package} (default: @code{yggdrasil})
  13897. Package object of Yggdrasil.
  13898. @item @code{json-config} (default: @code{'()})
  13899. Contents of @file{/etc/yggdrasil.conf}. Will be merged with
  13900. @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
  13901. the Guix store, which is readable to all users. @strong{Do not store your
  13902. private keys in it}. See the output of @code{yggdrasil -genconf} for a
  13903. quick overview of valid keys and their default values.
  13904. @item @code{autoconf?} (default: @code{#f})
  13905. Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
  13906. and peer with IPv6 neighbors.
  13907. @item @code{log-level} (default: @code{'info})
  13908. How much detail to include in logs. Use @code{'debug} for more detail.
  13909. @item @code{log-to} (default: @code{'stdout})
  13910. Where to send logs. By default, the service logs standard output to
  13911. @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
  13912. sends output to the running syslog service.
  13913. @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
  13914. What HJSON file to load sensitive data from. This is where private keys
  13915. should be stored, which are necessary to specify if you don't want a
  13916. randomized address after each restart. Use @code{#f} to disable. Options
  13917. defined in this file take precedence over @code{json-config}. Use the output
  13918. of @code{yggdrasil -genconf} as a starting point. To configure a static
  13919. address, delete everything except these options:
  13920. @itemize
  13921. @item @code{EncryptionPublicKey}
  13922. @item @code{EncryptionPrivateKey}
  13923. @item @code{SigningPublicKey}
  13924. @item @code{SigningPrivateKey}
  13925. @end itemize
  13926. @end table
  13927. @end deftp
  13928. @cindex IPFS
  13929. @defvr {Scheme Variable} ipfs-service-type
  13930. The service type for connecting to the @uref{https://ipfs.io,IPFS network},
  13931. a global, versioned, peer-to-peer file system. Pass it a
  13932. @code{ipfs-configuration} to change the ports used for the gateway and API.
  13933. Here's an example configuration, using some non-standard ports:
  13934. @lisp
  13935. ;; part of the operating-system declaration
  13936. (service ipfs-service-type
  13937. (ipfs-configuration
  13938. (gateway "/ip4/127.0.0.1/tcp/8880")
  13939. (api "/ip4/127.0.0.1/tcp/8881")))
  13940. @end lisp
  13941. @end defvr
  13942. @deftp {Data Type} ipfs-configuration
  13943. Data type representing the configuration of IPFS.
  13944. @table @asis
  13945. @item @code{package} (default: @code{go-ipfs})
  13946. Package object of IPFS.
  13947. @item @code{gateway} (default: @code{"/ip4/127.0.0.1/tcp/8082"})
  13948. Address of the gateway, in ‘multiaddress’ format.
  13949. @item @code{api} (default: @code{"/ip4/127.0.0.1/tcp/5001"})
  13950. Address of the API endpoint, in ‘multiaddress’ format.
  13951. @end table
  13952. @end deftp
  13953. @cindex keepalived
  13954. @deffn {Scheme Variable} keepalived-service-type
  13955. This is the type for the @uref{https://www.keepalived.org/, Keepalived}
  13956. routing software, @command{keepalived}. Its value must be an
  13957. @code{keepalived-configuration} record as in this example for master
  13958. machine:
  13959. @lisp
  13960. (service keepalived-service-type
  13961. (keepalived-configuration
  13962. (config-file (local-file "keepalived-master.conf"))))
  13963. @end lisp
  13964. where @file{keepalived-master.conf}:
  13965. @example
  13966. vrrp_instance my-group @{
  13967. state MASTER
  13968. interface enp9s0
  13969. virtual_router_id 100
  13970. priority 100
  13971. unicast_peer @{ 10.0.0.2 @}
  13972. virtual_ipaddress @{
  13973. 10.0.0.4/24
  13974. @}
  13975. @}
  13976. @end example
  13977. and for backup machine:
  13978. @lisp
  13979. (service keepalived-service-type
  13980. (keepalived-configuration
  13981. (config-file (local-file "keepalived-backup.conf"))))
  13982. @end lisp
  13983. where @file{keepalived-backup.conf}:
  13984. @example
  13985. vrrp_instance my-group @{
  13986. state BACKUP
  13987. interface enp9s0
  13988. virtual_router_id 100
  13989. priority 99
  13990. unicast_peer @{ 10.0.0.3 @}
  13991. virtual_ipaddress @{
  13992. 10.0.0.4/24
  13993. @}
  13994. @}
  13995. @end example
  13996. @end deffn
  13997. @node Unattended Upgrades
  13998. @subsection Unattended Upgrades
  13999. @cindex unattended upgrades
  14000. @cindex upgrades, unattended
  14001. Guix provides a service to perform @emph{unattended upgrades}:
  14002. periodically, the system automatically reconfigures itself from the
  14003. latest Guix. Guix System has several properties that make unattended
  14004. upgrades safe:
  14005. @itemize
  14006. @item
  14007. upgrades are transactional (either the upgrade succeeds or it fails, but
  14008. you cannot end up with an ``in-between'' system state);
  14009. @item
  14010. the upgrade log is kept---you can view it with @command{guix system
  14011. list-generations}---and you can roll back to any previous generation,
  14012. should the upgraded system fail to behave as intended;
  14013. @item
  14014. channel code is authenticated so you know you can only run genuine code
  14015. (@pxref{Channels});
  14016. @item
  14017. @command{guix system reconfigure} prevents downgrades, which makes it
  14018. immune to @dfn{downgrade attacks}.
  14019. @end itemize
  14020. To set up unattended upgrades, add an instance of
  14021. @code{unattended-upgrade-service-type} like the one below to the list of
  14022. your operating system services:
  14023. @lisp
  14024. (service unattended-upgrade-service-type)
  14025. @end lisp
  14026. The defaults above set up weekly upgrades: every Sunday at midnight.
  14027. You do not need to provide the operating system configuration file: it
  14028. uses @file{/run/current-system/configuration.scm}, which ensures it
  14029. always uses your latest configuration---@pxref{provenance-service-type},
  14030. for more information about this file.
  14031. There are several things that can be configured, in particular the
  14032. periodicity and services (daemons) to be restarted upon completion.
  14033. When the upgrade is successful, the service takes care of deleting
  14034. system generations older that some threshold, as per @command{guix
  14035. system delete-generations}. See the reference below for details.
  14036. To ensure that upgrades are actually happening, you can run
  14037. @command{guix system describe}. To investigate upgrade failures, visit
  14038. the unattended upgrade log file (see below).
  14039. @defvr {Scheme Variable} unattended-upgrade-service-type
  14040. This is the service type for unattended upgrades. It sets up an mcron
  14041. job (@pxref{Scheduled Job Execution}) that runs @command{guix system
  14042. reconfigure} from the latest version of the specified channels.
  14043. Its value must be a @code{unattended-upgrade-configuration} record (see
  14044. below).
  14045. @end defvr
  14046. @deftp {Data Type} unattended-upgrade-configuration
  14047. This data type represents the configuration of the unattended upgrade
  14048. service. The following fields are available:
  14049. @table @asis
  14050. @item @code{schedule} (default: @code{"30 01 * * 0"})
  14051. This is the schedule of upgrades, expressed as a gexp containing an
  14052. mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
  14053. mcron, GNU@tie{}mcron}).
  14054. @item @code{channels} (default: @code{#~%default-channels})
  14055. This gexp specifies the channels to use for the upgrade
  14056. (@pxref{Channels}). By default, the tip of the official @code{guix}
  14057. channel is used.
  14058. @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
  14059. This field specifies the operating system configuration file to use.
  14060. The default is to reuse the config file of the current configuration.
  14061. There are cases, though, where referring to
  14062. @file{/run/current-system/configuration.scm} is not enough, for instance
  14063. because that file refers to extra files (SSH public keys, extra
  14064. configuration files, etc.) @i{via} @code{local-file} and similar
  14065. constructs. For those cases, we recommend something along these lines:
  14066. @lisp
  14067. (unattended-upgrade-configuration
  14068. (operating-system-file
  14069. (file-append (local-file "." "config-dir" #:recursive? #t)
  14070. "/config.scm")))
  14071. @end lisp
  14072. The effect here is to import all of the current directory into the
  14073. store, and to refer to @file{config.scm} within that directory.
  14074. Therefore, uses of @code{local-file} within @file{config.scm} will work
  14075. as expected. @xref{G-Expressions}, for information about
  14076. @code{local-file} and @code{file-append}.
  14077. @item @code{services-to-restart} (default: @code{'(mcron)})
  14078. This field specifies the Shepherd services to restart when the upgrade
  14079. completes.
  14080. Those services are restarted right away upon completion, as with
  14081. @command{herd restart}, which ensures that the latest version is
  14082. running---remember that by default @command{guix system reconfigure}
  14083. only restarts services that are not currently running, which is
  14084. conservative: it minimizes disruption but leaves outdated services
  14085. running.
  14086. Use @command{herd status} to find out candidates for restarting.
  14087. @xref{Services}, for general information about services. Common
  14088. services to restart would include @code{ntpd} and @code{ssh-daemon}.
  14089. By default, the @code{mcron} service is restarted. This ensures that
  14090. the latest version of the unattended upgrade job will be used next time.
  14091. @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
  14092. This is the expiration time in seconds for system generations. System
  14093. generations older that this amount of time are deleted with
  14094. @command{guix system delete-generations} when an upgrade completes.
  14095. @quotation Note
  14096. The unattended upgrade service does not run the garbage collector. You
  14097. will probably want to set up your own mcron job to run @command{guix gc}
  14098. periodically.
  14099. @end quotation
  14100. @item @code{maximum-duration} (default: @code{3600})
  14101. Maximum duration in seconds for the upgrade; past that time, the upgrade
  14102. aborts.
  14103. This is primarily useful to ensure the upgrade does not end up
  14104. rebuilding or re-downloading ``the world''.
  14105. @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
  14106. File where unattended upgrades are logged.
  14107. @end table
  14108. @end deftp
  14109. @node X Window
  14110. @subsection X Window
  14111. @cindex X11
  14112. @cindex X Window System
  14113. @cindex login manager
  14114. Support for the X Window graphical display system---specifically
  14115. Xorg---is provided by the @code{(gnu services xorg)} module. Note that
  14116. there is no @code{xorg-service} procedure. Instead, the X server is
  14117. started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
  14118. @cindex GDM
  14119. @cindex GNOME, login manager
  14120. GDM of course allows users to log in into window managers and desktop
  14121. environments other than GNOME; for those using GNOME, GDM is required for
  14122. features such as automatic screen locking.
  14123. @cindex window manager
  14124. To use X11, you must install at least one @dfn{window manager}---for
  14125. example the @code{windowmaker} or @code{openbox} packages---preferably
  14126. by adding it to the @code{packages} field of your operating system
  14127. definition (@pxref{operating-system Reference, system-wide packages}).
  14128. @defvr {Scheme Variable} gdm-service-type
  14129. This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
  14130. Desktop Manager} (GDM), a program that manages graphical display servers and
  14131. handles graphical user logins. Its value must be a @code{gdm-configuration}
  14132. (see below).
  14133. @cindex session types (X11)
  14134. @cindex X11 session types
  14135. GDM looks for @dfn{session types} described by the @file{.desktop} files in
  14136. @file{/run/current-system/profile/share/xsessions} and allows users to choose
  14137. a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
  14138. and @code{i3} provide @file{.desktop} files; adding them to the system-wide
  14139. set of packages automatically makes them available at the log-in screen.
  14140. In addition, @file{~/.xsession} files are honored. When available,
  14141. @file{~/.xsession} must be an executable that starts a window manager
  14142. and/or other X clients.
  14143. @end defvr
  14144. @deftp {Data Type} gdm-configuration
  14145. @table @asis
  14146. @item @code{auto-login?} (default: @code{#f})
  14147. @itemx @code{default-user} (default: @code{#f})
  14148. When @code{auto-login?} is false, GDM presents a log-in screen.
  14149. When @code{auto-login?} is true, GDM logs in directly as
  14150. @code{default-user}.
  14151. @item @code{debug?} (default: @code{#f})
  14152. When true, GDM writes debug messages to its log.
  14153. @item @code{gnome-shell-assets} (default: ...)
  14154. List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
  14155. @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
  14156. Configuration of the Xorg graphical server.
  14157. @item @code{xsession} (default: @code{(xinitrc)})
  14158. Script to run before starting a X session.
  14159. @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
  14160. File name of the @code{dbus-daemon} executable.
  14161. @item @code{gdm} (default: @code{gdm})
  14162. The GDM package to use.
  14163. @end table
  14164. @end deftp
  14165. @defvr {Scheme Variable} slim-service-type
  14166. This is the type for the SLiM graphical login manager for X11.
  14167. Like GDM, SLiM looks for session types described by @file{.desktop} files and
  14168. allows users to choose a session from the log-in screen using @kbd{F1}. It
  14169. also honors @file{~/.xsession} files.
  14170. Unlike GDM, SLiM does not spawn the user session on a different VT after
  14171. logging in, which means that you can only start one graphical session. If you
  14172. want to be able to run multiple graphical sessions at the same time you have
  14173. to add multiple SLiM services to your system services. The following example
  14174. shows how to replace the default GDM service with two SLiM services on tty7
  14175. and tty8.
  14176. @lisp
  14177. (use-modules (gnu services)
  14178. (gnu services desktop)
  14179. (gnu services xorg)
  14180. (srfi srfi-1)) ;for 'remove'
  14181. (operating-system
  14182. ;; ...
  14183. (services (cons* (service slim-service-type (slim-configuration
  14184. (display ":0")
  14185. (vt "vt7")))
  14186. (service slim-service-type (slim-configuration
  14187. (display ":1")
  14188. (vt "vt8")))
  14189. (remove (lambda (service)
  14190. (eq? (service-kind service) gdm-service-type))
  14191. %desktop-services))))
  14192. @end lisp
  14193. @end defvr
  14194. @deftp {Data Type} slim-configuration
  14195. Data type representing the configuration of @code{slim-service-type}.
  14196. @table @asis
  14197. @item @code{allow-empty-passwords?} (default: @code{#t})
  14198. Whether to allow logins with empty passwords.
  14199. @item @code{auto-login?} (default: @code{#f})
  14200. @itemx @code{default-user} (default: @code{""})
  14201. When @code{auto-login?} is false, SLiM presents a log-in screen.
  14202. When @code{auto-login?} is true, SLiM logs in directly as
  14203. @code{default-user}.
  14204. @item @code{theme} (default: @code{%default-slim-theme})
  14205. @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
  14206. The graphical theme to use and its name.
  14207. @item @code{auto-login-session} (default: @code{#f})
  14208. If true, this must be the name of the executable to start as the default
  14209. session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
  14210. If false, a session described by one of the available @file{.desktop}
  14211. files in @code{/run/current-system/profile} and @code{~/.guix-profile}
  14212. will be used.
  14213. @quotation Note
  14214. You must install at least one window manager in the system profile or in
  14215. your user profile. Failing to do that, if @code{auto-login-session} is
  14216. false, you will be unable to log in.
  14217. @end quotation
  14218. @item @code{xorg-configuration} (default @code{(xorg-configuration)})
  14219. Configuration of the Xorg graphical server.
  14220. @item @code{display} (default @code{":0"})
  14221. The display on which to start the Xorg graphical server.
  14222. @item @code{vt} (default @code{"vt7"})
  14223. The VT on which to start the Xorg graphical server.
  14224. @item @code{xauth} (default: @code{xauth})
  14225. The XAuth package to use.
  14226. @item @code{shepherd} (default: @code{shepherd})
  14227. The Shepherd package used when invoking @command{halt} and
  14228. @command{reboot}.
  14229. @item @code{sessreg} (default: @code{sessreg})
  14230. The sessreg package used in order to register the session.
  14231. @item @code{slim} (default: @code{slim})
  14232. The SLiM package to use.
  14233. @end table
  14234. @end deftp
  14235. @defvr {Scheme Variable} %default-theme
  14236. @defvrx {Scheme Variable} %default-theme-name
  14237. The default SLiM theme and its name.
  14238. @end defvr
  14239. @deftp {Data Type} sddm-configuration
  14240. This is the data type representing the SDDM service configuration.
  14241. @table @asis
  14242. @item @code{display-server} (default: "x11")
  14243. Select display server to use for the greeter. Valid values are
  14244. @samp{"x11"} or @samp{"wayland"}.
  14245. @item @code{numlock} (default: "on")
  14246. Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
  14247. @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
  14248. Command to run when halting.
  14249. @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
  14250. Command to run when rebooting.
  14251. @item @code{theme} (default "maldives")
  14252. Theme to use. Default themes provided by SDDM are @samp{"elarun"},
  14253. @samp{"maldives"} or @samp{"maya"}.
  14254. @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
  14255. Directory to look for themes.
  14256. @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
  14257. Directory to look for faces.
  14258. @item @code{default-path} (default "/run/current-system/profile/bin")
  14259. Default PATH to use.
  14260. @item @code{minimum-uid} (default: 1000)
  14261. Minimum UID displayed in SDDM and allowed for log-in.
  14262. @item @code{maximum-uid} (default: 2000)
  14263. Maximum UID to display in SDDM.
  14264. @item @code{remember-last-user?} (default #t)
  14265. Remember last user.
  14266. @item @code{remember-last-session?} (default #t)
  14267. Remember last session.
  14268. @item @code{hide-users} (default "")
  14269. Usernames to hide from SDDM greeter.
  14270. @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
  14271. Users with shells listed will be hidden from the SDDM greeter.
  14272. @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
  14273. Script to run before starting a wayland session.
  14274. @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
  14275. Directory to look for desktop files starting wayland sessions.
  14276. @item @code{xorg-configuration} (default @code{(xorg-configuration)})
  14277. Configuration of the Xorg graphical server.
  14278. @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
  14279. Path to xauth.
  14280. @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
  14281. Path to Xephyr.
  14282. @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
  14283. Script to run after starting xorg-server.
  14284. @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
  14285. Script to run before stopping xorg-server.
  14286. @item @code{xsession-command} (default: @code{xinitrc})
  14287. Script to run before starting a X session.
  14288. @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
  14289. Directory to look for desktop files starting X sessions.
  14290. @item @code{minimum-vt} (default: 7)
  14291. Minimum VT to use.
  14292. @item @code{auto-login-user} (default "")
  14293. User to use for auto-login.
  14294. @item @code{auto-login-session} (default "")
  14295. Desktop file to use for auto-login.
  14296. @item @code{relogin?} (default #f)
  14297. Relogin after logout.
  14298. @end table
  14299. @end deftp
  14300. @cindex login manager
  14301. @cindex X11 login
  14302. @defvr {Scheme Variable} sddm-service-type
  14303. This is the type of the service to run the
  14304. @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
  14305. must be a @code{sddm-configuration} record (see below).
  14306. Here's an example use:
  14307. @lisp
  14308. (service sddm-service-type
  14309. (sddm-configuration
  14310. (auto-login-user "alice")
  14311. (auto-login-session "xfce.desktop")))
  14312. @end lisp
  14313. @end defvr
  14314. @deftp {Data Type} sddm-configuration
  14315. This data type represents the configuration of the SDDM login manager.
  14316. The available fields are:
  14317. @table @asis
  14318. @item @code{sddm} (default: @code{sddm})
  14319. The SDDM package to use.
  14320. @item @code{display-server} (default: @code{"x11"})
  14321. This must be either @code{"x11"} or @code{"wayland"}.
  14322. @c FIXME: Add more fields.
  14323. @item @code{auto-login-user} (default: @code{""})
  14324. If non-empty, this is the user account under which to log in
  14325. automatically.
  14326. @item @code{auto-login-session} (default: @code{""})
  14327. If non-empty, this is the @file{.desktop} file name to use as the
  14328. auto-login session.
  14329. @end table
  14330. @end deftp
  14331. @cindex Xorg, configuration
  14332. @deftp {Data Type} xorg-configuration
  14333. This data type represents the configuration of the Xorg graphical display
  14334. server. Note that there is no Xorg service; instead, the X server is started
  14335. by a ``display manager'' such as GDM, SDDM, and SLiM@. Thus, the configuration
  14336. of these display managers aggregates an @code{xorg-configuration} record.
  14337. @table @asis
  14338. @item @code{modules} (default: @code{%default-xorg-modules})
  14339. This is a list of @dfn{module packages} loaded by the Xorg
  14340. server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
  14341. @item @code{fonts} (default: @code{%default-xorg-fonts})
  14342. This is a list of font directories to add to the server's @dfn{font path}.
  14343. @item @code{drivers} (default: @code{'()})
  14344. This must be either the empty list, in which case Xorg chooses a graphics
  14345. driver automatically, or a list of driver names that will be tried in this
  14346. order---e.g., @code{("modesetting" "vesa")}.
  14347. @item @code{resolutions} (default: @code{'()})
  14348. When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
  14349. resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
  14350. 768) (640 480))}.
  14351. @cindex keyboard layout, for Xorg
  14352. @cindex keymap, for Xorg
  14353. @item @code{keyboard-layout} (default: @code{#f})
  14354. If this is @code{#f}, Xorg uses the default keyboard layout---usually US
  14355. English (``qwerty'') for a 105-key PC keyboard.
  14356. Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
  14357. layout in use when Xorg is running. @xref{Keyboard Layout}, for more
  14358. information on how to specify the keyboard layout.
  14359. @item @code{extra-config} (default: @code{'()})
  14360. This is a list of strings or objects appended to the configuration file. It
  14361. is used to pass extra text to be added verbatim to the configuration file.
  14362. @item @code{server} (default: @code{xorg-server})
  14363. This is the package providing the Xorg server.
  14364. @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
  14365. This is the list of command-line arguments to pass to the X server. The
  14366. default is @code{-nolisten tcp}.
  14367. @end table
  14368. @end deftp
  14369. @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
  14370. [@var{login-manager-service-type}]
  14371. Tell the log-in manager (of type @var{login-manager-service-type}) to use
  14372. @var{config}, an @code{<xorg-configuration>} record.
  14373. Since the Xorg configuration is embedded in the log-in manager's
  14374. configuration---e.g., @code{gdm-configuration}---this procedure provides a
  14375. shorthand to set the Xorg configuration.
  14376. @end deffn
  14377. @deffn {Scheme Procedure} xorg-start-command [@var{config}]
  14378. Return a @code{startx} script in which the modules, fonts, etc. specified
  14379. in @var{config}, are available. The result should be used in place of
  14380. @code{startx}.
  14381. Usually the X server is started by a login manager.
  14382. @end deffn
  14383. @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
  14384. Add @var{package}, a package for a screen locker or screen saver whose
  14385. command is @var{program}, to the set of setuid programs and add a PAM entry
  14386. for it. For example:
  14387. @lisp
  14388. (screen-locker-service xlockmore "xlock")
  14389. @end lisp
  14390. makes the good ol' XlockMore usable.
  14391. @end deffn
  14392. @node Printing Services
  14393. @subsection Printing Services
  14394. @cindex printer support with CUPS
  14395. The @code{(gnu services cups)} module provides a Guix service definition
  14396. for the CUPS printing service. To add printer support to a Guix
  14397. system, add a @code{cups-service} to the operating system definition:
  14398. @deffn {Scheme Variable} cups-service-type
  14399. The service type for the CUPS print server. Its value should be a valid
  14400. CUPS configuration (see below). To use the default settings, simply
  14401. write:
  14402. @lisp
  14403. (service cups-service-type)
  14404. @end lisp
  14405. @end deffn
  14406. The CUPS configuration controls the basic things about your CUPS
  14407. installation: what interfaces it listens on, what to do if a print job
  14408. fails, how much logging to do, and so on. To actually add a printer,
  14409. you have to visit the @url{http://localhost:631} URL, or use a tool such
  14410. as GNOME's printer configuration services. By default, configuring a
  14411. CUPS service will generate a self-signed certificate if needed, for
  14412. secure connections to the print server.
  14413. Suppose you want to enable the Web interface of CUPS and also add
  14414. support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
  14415. package and for HP printers @i{via} the @code{hplip-minimal} package.
  14416. You can do that directly, like this (you need to use the
  14417. @code{(gnu packages cups)} module):
  14418. @lisp
  14419. (service cups-service-type
  14420. (cups-configuration
  14421. (web-interface? #t)
  14422. (extensions
  14423. (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
  14424. @end lisp
  14425. Note: If you wish to use the Qt5 based GUI which comes with the hplip
  14426. package then it is suggested that you install the @code{hplip} package,
  14427. either in your OS configuration file or as your user.
  14428. The available configuration parameters follow. Each parameter
  14429. definition is preceded by its type; for example, @samp{string-list foo}
  14430. indicates that the @code{foo} parameter should be specified as a list of
  14431. strings. There is also a way to specify the configuration as a string,
  14432. if you have an old @code{cupsd.conf} file that you want to port over
  14433. from some other system; see the end for more details.
  14434. @c The following documentation was initially generated by
  14435. @c (generate-documentation) in (gnu services cups). Manually maintained
  14436. @c documentation is better, so we shouldn't hesitate to edit below as
  14437. @c needed. However if the change you want to make to this documentation
  14438. @c can be done in an automated way, it's probably easier to change
  14439. @c (generate-documentation) than to make it below and have to deal with
  14440. @c the churn as CUPS updates.
  14441. Available @code{cups-configuration} fields are:
  14442. @deftypevr {@code{cups-configuration} parameter} package cups
  14443. The CUPS package.
  14444. @end deftypevr
  14445. @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
  14446. Drivers and other extensions to the CUPS package.
  14447. @end deftypevr
  14448. @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
  14449. Configuration of where to write logs, what directories to use for print
  14450. spools, and related privileged configuration parameters.
  14451. Available @code{files-configuration} fields are:
  14452. @deftypevr {@code{files-configuration} parameter} log-location access-log
  14453. Defines the access log filename. Specifying a blank filename disables
  14454. access log generation. The value @code{stderr} causes log entries to be
  14455. sent to the standard error file when the scheduler is running in the
  14456. foreground, or to the system log daemon when run in the background. The
  14457. value @code{syslog} causes log entries to be sent to the system log
  14458. daemon. The server name may be included in filenames using the string
  14459. @code{%s}, as in @code{/var/log/cups/%s-access_log}.
  14460. Defaults to @samp{"/var/log/cups/access_log"}.
  14461. @end deftypevr
  14462. @deftypevr {@code{files-configuration} parameter} file-name cache-dir
  14463. Where CUPS should cache data.
  14464. Defaults to @samp{"/var/cache/cups"}.
  14465. @end deftypevr
  14466. @deftypevr {@code{files-configuration} parameter} string config-file-perm
  14467. Specifies the permissions for all configuration files that the scheduler
  14468. writes.
  14469. Note that the permissions for the printers.conf file are currently
  14470. masked to only allow access from the scheduler user (typically root).
  14471. This is done because printer device URIs sometimes contain sensitive
  14472. authentication information that should not be generally known on the
  14473. system. There is no way to disable this security feature.
  14474. Defaults to @samp{"0640"}.
  14475. @end deftypevr
  14476. @deftypevr {@code{files-configuration} parameter} log-location error-log
  14477. Defines the error log filename. Specifying a blank filename disables
  14478. error log generation. The value @code{stderr} causes log entries to be
  14479. sent to the standard error file when the scheduler is running in the
  14480. foreground, or to the system log daemon when run in the background. The
  14481. value @code{syslog} causes log entries to be sent to the system log
  14482. daemon. The server name may be included in filenames using the string
  14483. @code{%s}, as in @code{/var/log/cups/%s-error_log}.
  14484. Defaults to @samp{"/var/log/cups/error_log"}.
  14485. @end deftypevr
  14486. @deftypevr {@code{files-configuration} parameter} string fatal-errors
  14487. Specifies which errors are fatal, causing the scheduler to exit. The
  14488. kind strings are:
  14489. @table @code
  14490. @item none
  14491. No errors are fatal.
  14492. @item all
  14493. All of the errors below are fatal.
  14494. @item browse
  14495. Browsing initialization errors are fatal, for example failed connections
  14496. to the DNS-SD daemon.
  14497. @item config
  14498. Configuration file syntax errors are fatal.
  14499. @item listen
  14500. Listen or Port errors are fatal, except for IPv6 failures on the
  14501. loopback or @code{any} addresses.
  14502. @item log
  14503. Log file creation or write errors are fatal.
  14504. @item permissions
  14505. Bad startup file permissions are fatal, for example shared TLS
  14506. certificate and key files with world-read permissions.
  14507. @end table
  14508. Defaults to @samp{"all -browse"}.
  14509. @end deftypevr
  14510. @deftypevr {@code{files-configuration} parameter} boolean file-device?
  14511. Specifies whether the file pseudo-device can be used for new printer
  14512. queues. The URI @uref{file:///dev/null} is always allowed.
  14513. Defaults to @samp{#f}.
  14514. @end deftypevr
  14515. @deftypevr {@code{files-configuration} parameter} string group
  14516. Specifies the group name or ID that will be used when executing external
  14517. programs.
  14518. Defaults to @samp{"lp"}.
  14519. @end deftypevr
  14520. @deftypevr {@code{files-configuration} parameter} string log-file-perm
  14521. Specifies the permissions for all log files that the scheduler writes.
  14522. Defaults to @samp{"0644"}.
  14523. @end deftypevr
  14524. @deftypevr {@code{files-configuration} parameter} log-location page-log
  14525. Defines the page log filename. Specifying a blank filename disables
  14526. page log generation. The value @code{stderr} causes log entries to be
  14527. sent to the standard error file when the scheduler is running in the
  14528. foreground, or to the system log daemon when run in the background. The
  14529. value @code{syslog} causes log entries to be sent to the system log
  14530. daemon. The server name may be included in filenames using the string
  14531. @code{%s}, as in @code{/var/log/cups/%s-page_log}.
  14532. Defaults to @samp{"/var/log/cups/page_log"}.
  14533. @end deftypevr
  14534. @deftypevr {@code{files-configuration} parameter} string remote-root
  14535. Specifies the username that is associated with unauthenticated accesses
  14536. by clients claiming to be the root user. The default is @code{remroot}.
  14537. Defaults to @samp{"remroot"}.
  14538. @end deftypevr
  14539. @deftypevr {@code{files-configuration} parameter} file-name request-root
  14540. Specifies the directory that contains print jobs and other HTTP request
  14541. data.
  14542. Defaults to @samp{"/var/spool/cups"}.
  14543. @end deftypevr
  14544. @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
  14545. Specifies the level of security sandboxing that is applied to print
  14546. filters, backends, and other child processes of the scheduler; either
  14547. @code{relaxed} or @code{strict}. This directive is currently only
  14548. used/supported on macOS.
  14549. Defaults to @samp{strict}.
  14550. @end deftypevr
  14551. @deftypevr {@code{files-configuration} parameter} file-name server-keychain
  14552. Specifies the location of TLS certificates and private keys. CUPS will
  14553. look for public and private keys in this directory: @file{.crt} files
  14554. for PEM-encoded certificates and corresponding @file{.key} files for
  14555. PEM-encoded private keys.
  14556. Defaults to @samp{"/etc/cups/ssl"}.
  14557. @end deftypevr
  14558. @deftypevr {@code{files-configuration} parameter} file-name server-root
  14559. Specifies the directory containing the server configuration files.
  14560. Defaults to @samp{"/etc/cups"}.
  14561. @end deftypevr
  14562. @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
  14563. Specifies whether the scheduler calls fsync(2) after writing
  14564. configuration or state files.
  14565. Defaults to @samp{#f}.
  14566. @end deftypevr
  14567. @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
  14568. Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
  14569. @end deftypevr
  14570. @deftypevr {@code{files-configuration} parameter} file-name temp-dir
  14571. Specifies the directory where temporary files are stored.
  14572. Defaults to @samp{"/var/spool/cups/tmp"}.
  14573. @end deftypevr
  14574. @deftypevr {@code{files-configuration} parameter} string user
  14575. Specifies the user name or ID that is used when running external
  14576. programs.
  14577. Defaults to @samp{"lp"}.
  14578. @end deftypevr
  14579. @deftypevr {@code{files-configuration} parameter} string set-env
  14580. Set the specified environment variable to be passed to child processes.
  14581. Defaults to @samp{"variable value"}.
  14582. @end deftypevr
  14583. @end deftypevr
  14584. @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
  14585. Specifies the logging level for the AccessLog file. The @code{config}
  14586. level logs when printers and classes are added, deleted, or modified and
  14587. when configuration files are accessed or updated. The @code{actions}
  14588. level logs when print jobs are submitted, held, released, modified, or
  14589. canceled, and any of the conditions for @code{config}. The @code{all}
  14590. level logs all requests.
  14591. Defaults to @samp{actions}.
  14592. @end deftypevr
  14593. @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
  14594. Specifies whether to purge job history data automatically when it is no
  14595. longer required for quotas.
  14596. Defaults to @samp{#f}.
  14597. @end deftypevr
  14598. @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
  14599. Specifies a list of DNS-SD sub-types to advertise for each shared printer.
  14600. For example, @samp{"_cups" "_print"} will tell network clients that both
  14601. CUPS sharing and IPP Everywhere are supported.
  14602. Defaults to @samp{"_cups"}.
  14603. @end deftypevr
  14604. @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
  14605. Specifies which protocols to use for local printer sharing.
  14606. Defaults to @samp{dnssd}.
  14607. @end deftypevr
  14608. @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
  14609. Specifies whether the CUPS web interface is advertised.
  14610. Defaults to @samp{#f}.
  14611. @end deftypevr
  14612. @deftypevr {@code{cups-configuration} parameter} boolean browsing?
  14613. Specifies whether shared printers are advertised.
  14614. Defaults to @samp{#f}.
  14615. @end deftypevr
  14616. @deftypevr {@code{cups-configuration} parameter} string classification
  14617. Specifies the security classification of the server. Any valid banner
  14618. name can be used, including @samp{"classified"}, @samp{"confidential"},
  14619. @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
  14620. banner can be omitted to disable secure printing functions.
  14621. Defaults to @samp{""}.
  14622. @end deftypevr
  14623. @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
  14624. Specifies whether users may override the classification (cover page) of
  14625. individual print jobs using the @code{job-sheets} option.
  14626. Defaults to @samp{#f}.
  14627. @end deftypevr
  14628. @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
  14629. Specifies the default type of authentication to use.
  14630. Defaults to @samp{Basic}.
  14631. @end deftypevr
  14632. @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
  14633. Specifies whether encryption will be used for authenticated requests.
  14634. Defaults to @samp{Required}.
  14635. @end deftypevr
  14636. @deftypevr {@code{cups-configuration} parameter} string default-language
  14637. Specifies the default language to use for text and web content.
  14638. Defaults to @samp{"en"}.
  14639. @end deftypevr
  14640. @deftypevr {@code{cups-configuration} parameter} string default-paper-size
  14641. Specifies the default paper size for new print queues. @samp{"Auto"}
  14642. uses a locale-specific default, while @samp{"None"} specifies there is
  14643. no default paper size. Specific size names are typically
  14644. @samp{"Letter"} or @samp{"A4"}.
  14645. Defaults to @samp{"Auto"}.
  14646. @end deftypevr
  14647. @deftypevr {@code{cups-configuration} parameter} string default-policy
  14648. Specifies the default access policy to use.
  14649. Defaults to @samp{"default"}.
  14650. @end deftypevr
  14651. @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
  14652. Specifies whether local printers are shared by default.
  14653. Defaults to @samp{#t}.
  14654. @end deftypevr
  14655. @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
  14656. Specifies the delay for updating of configuration and state files, in
  14657. seconds. A value of 0 causes the update to happen as soon as possible,
  14658. typically within a few milliseconds.
  14659. Defaults to @samp{30}.
  14660. @end deftypevr
  14661. @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
  14662. Specifies what to do when an error occurs. Possible values are
  14663. @code{abort-job}, which will discard the failed print job;
  14664. @code{retry-job}, which will retry the job at a later time;
  14665. @code{retry-current-job}, which retries the failed job immediately; and
  14666. @code{stop-printer}, which stops the printer.
  14667. Defaults to @samp{stop-printer}.
  14668. @end deftypevr
  14669. @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
  14670. Specifies the maximum cost of filters that are run concurrently, which
  14671. can be used to minimize disk, memory, and CPU resource problems. A
  14672. limit of 0 disables filter limiting. An average print to a
  14673. non-PostScript printer needs a filter limit of about 200. A PostScript
  14674. printer needs about half that (100). Setting the limit below these
  14675. thresholds will effectively limit the scheduler to printing a single job
  14676. at any time.
  14677. Defaults to @samp{0}.
  14678. @end deftypevr
  14679. @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
  14680. Specifies the scheduling priority of filters that are run to print a
  14681. job. The nice value ranges from 0, the highest priority, to 19, the
  14682. lowest priority.
  14683. Defaults to @samp{0}.
  14684. @end deftypevr
  14685. @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
  14686. Specifies whether to do reverse lookups on connecting clients. The
  14687. @code{double} setting causes @code{cupsd} to verify that the hostname
  14688. resolved from the address matches one of the addresses returned for that
  14689. hostname. Double lookups also prevent clients with unregistered
  14690. addresses from connecting to your server. Only set this option to
  14691. @code{#t} or @code{double} if absolutely required.
  14692. Defaults to @samp{#f}.
  14693. @end deftypevr
  14694. @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
  14695. Specifies the number of seconds to wait before killing the filters and
  14696. backend associated with a canceled or held job.
  14697. Defaults to @samp{30}.
  14698. @end deftypevr
  14699. @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
  14700. Specifies the interval between retries of jobs in seconds. This is
  14701. typically used for fax queues but can also be used with normal print
  14702. queues whose error policy is @code{retry-job} or
  14703. @code{retry-current-job}.
  14704. Defaults to @samp{30}.
  14705. @end deftypevr
  14706. @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
  14707. Specifies the number of retries that are done for jobs. This is
  14708. typically used for fax queues but can also be used with normal print
  14709. queues whose error policy is @code{retry-job} or
  14710. @code{retry-current-job}.
  14711. Defaults to @samp{5}.
  14712. @end deftypevr
  14713. @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
  14714. Specifies whether to support HTTP keep-alive connections.
  14715. Defaults to @samp{#t}.
  14716. @end deftypevr
  14717. @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
  14718. Specifies how long an idle client connection remains open, in seconds.
  14719. Defaults to @samp{30}.
  14720. @end deftypevr
  14721. @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
  14722. Specifies the maximum size of print files, IPP requests, and HTML form
  14723. data. A limit of 0 disables the limit check.
  14724. Defaults to @samp{0}.
  14725. @end deftypevr
  14726. @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
  14727. Listens on the specified interfaces for connections. Valid values are
  14728. of the form @var{address}:@var{port}, where @var{address} is either an
  14729. IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
  14730. indicate all addresses. Values can also be file names of local UNIX
  14731. domain sockets. The Listen directive is similar to the Port directive
  14732. but allows you to restrict access to specific interfaces or networks.
  14733. @end deftypevr
  14734. @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
  14735. Specifies the number of pending connections that will be allowed. This
  14736. normally only affects very busy servers that have reached the MaxClients
  14737. limit, but can also be triggered by large numbers of simultaneous
  14738. connections. When the limit is reached, the operating system will
  14739. refuse additional connections until the scheduler can accept the pending
  14740. ones.
  14741. Defaults to @samp{128}.
  14742. @end deftypevr
  14743. @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
  14744. Specifies a set of additional access controls.
  14745. Available @code{location-access-controls} fields are:
  14746. @deftypevr {@code{location-access-controls} parameter} file-name path
  14747. Specifies the URI path to which the access control applies.
  14748. @end deftypevr
  14749. @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
  14750. Access controls for all access to this path, in the same format as the
  14751. @code{access-controls} of @code{operation-access-control}.
  14752. Defaults to @samp{()}.
  14753. @end deftypevr
  14754. @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
  14755. Access controls for method-specific access to this path.
  14756. Defaults to @samp{()}.
  14757. Available @code{method-access-controls} fields are:
  14758. @deftypevr {@code{method-access-controls} parameter} boolean reverse?
  14759. If @code{#t}, apply access controls to all methods except the listed
  14760. methods. Otherwise apply to only the listed methods.
  14761. Defaults to @samp{#f}.
  14762. @end deftypevr
  14763. @deftypevr {@code{method-access-controls} parameter} method-list methods
  14764. Methods to which this access control applies.
  14765. Defaults to @samp{()}.
  14766. @end deftypevr
  14767. @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
  14768. Access control directives, as a list of strings. Each string should be
  14769. one directive, such as @samp{"Order allow,deny"}.
  14770. Defaults to @samp{()}.
  14771. @end deftypevr
  14772. @end deftypevr
  14773. @end deftypevr
  14774. @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
  14775. Specifies the number of debugging messages that are retained for logging
  14776. if an error occurs in a print job. Debug messages are logged regardless
  14777. of the LogLevel setting.
  14778. Defaults to @samp{100}.
  14779. @end deftypevr
  14780. @deftypevr {@code{cups-configuration} parameter} log-level log-level
  14781. Specifies the level of logging for the ErrorLog file. The value
  14782. @code{none} stops all logging while @code{debug2} logs everything.
  14783. Defaults to @samp{info}.
  14784. @end deftypevr
  14785. @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
  14786. Specifies the format of the date and time in the log files. The value
  14787. @code{standard} logs whole seconds while @code{usecs} logs microseconds.
  14788. Defaults to @samp{standard}.
  14789. @end deftypevr
  14790. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
  14791. Specifies the maximum number of simultaneous clients that are allowed by
  14792. the scheduler.
  14793. Defaults to @samp{100}.
  14794. @end deftypevr
  14795. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
  14796. Specifies the maximum number of simultaneous clients that are allowed
  14797. from a single address.
  14798. Defaults to @samp{100}.
  14799. @end deftypevr
  14800. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
  14801. Specifies the maximum number of copies that a user can print of each
  14802. job.
  14803. Defaults to @samp{9999}.
  14804. @end deftypevr
  14805. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
  14806. Specifies the maximum time a job may remain in the @code{indefinite}
  14807. hold state before it is canceled. A value of 0 disables cancellation of
  14808. held jobs.
  14809. Defaults to @samp{0}.
  14810. @end deftypevr
  14811. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
  14812. Specifies the maximum number of simultaneous jobs that are allowed. Set
  14813. to 0 to allow an unlimited number of jobs.
  14814. Defaults to @samp{500}.
  14815. @end deftypevr
  14816. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
  14817. Specifies the maximum number of simultaneous jobs that are allowed per
  14818. printer. A value of 0 allows up to MaxJobs jobs per printer.
  14819. Defaults to @samp{0}.
  14820. @end deftypevr
  14821. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
  14822. Specifies the maximum number of simultaneous jobs that are allowed per
  14823. user. A value of 0 allows up to MaxJobs jobs per user.
  14824. Defaults to @samp{0}.
  14825. @end deftypevr
  14826. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
  14827. Specifies the maximum time a job may take to print before it is
  14828. canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
  14829. Defaults to @samp{10800}.
  14830. @end deftypevr
  14831. @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
  14832. Specifies the maximum size of the log files before they are rotated, in
  14833. bytes. The value 0 disables log rotation.
  14834. Defaults to @samp{1048576}.
  14835. @end deftypevr
  14836. @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
  14837. Specifies the maximum amount of time to allow between files in a
  14838. multiple file print job, in seconds.
  14839. Defaults to @samp{300}.
  14840. @end deftypevr
  14841. @deftypevr {@code{cups-configuration} parameter} string page-log-format
  14842. Specifies the format of PageLog lines. Sequences beginning with percent
  14843. (@samp{%}) characters are replaced with the corresponding information,
  14844. while all other characters are copied literally. The following percent
  14845. sequences are recognized:
  14846. @table @samp
  14847. @item %%
  14848. insert a single percent character
  14849. @item %@{name@}
  14850. insert the value of the specified IPP attribute
  14851. @item %C
  14852. insert the number of copies for the current page
  14853. @item %P
  14854. insert the current page number
  14855. @item %T
  14856. insert the current date and time in common log format
  14857. @item %j
  14858. insert the job ID
  14859. @item %p
  14860. insert the printer name
  14861. @item %u
  14862. insert the username
  14863. @end table
  14864. A value of the empty string disables page logging. The string @code{%p
  14865. %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
  14866. %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
  14867. standard items.
  14868. Defaults to @samp{""}.
  14869. @end deftypevr
  14870. @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
  14871. Passes the specified environment variable(s) to child processes; a list
  14872. of strings.
  14873. Defaults to @samp{()}.
  14874. @end deftypevr
  14875. @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
  14876. Specifies named access control policies.
  14877. Available @code{policy-configuration} fields are:
  14878. @deftypevr {@code{policy-configuration} parameter} string name
  14879. Name of the policy.
  14880. @end deftypevr
  14881. @deftypevr {@code{policy-configuration} parameter} string job-private-access
  14882. Specifies an access list for a job's private values. @code{@@ACL} maps
  14883. to the printer's requesting-user-name-allowed or
  14884. requesting-user-name-denied values. @code{@@OWNER} maps to the job's
  14885. owner. @code{@@SYSTEM} maps to the groups listed for the
  14886. @code{system-group} field of the @code{files-config} configuration,
  14887. which is reified into the @code{cups-files.conf(5)} file. Other
  14888. possible elements of the access list include specific user names, and
  14889. @code{@@@var{group}} to indicate members of a specific group. The
  14890. access list may also be simply @code{all} or @code{default}.
  14891. Defaults to @samp{"@@OWNER @@SYSTEM"}.
  14892. @end deftypevr
  14893. @deftypevr {@code{policy-configuration} parameter} string job-private-values
  14894. Specifies the list of job values to make private, or @code{all},
  14895. @code{default}, or @code{none}.
  14896. Defaults to @samp{"job-name job-originating-host-name
  14897. job-originating-user-name phone"}.
  14898. @end deftypevr
  14899. @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
  14900. Specifies an access list for a subscription's private values.
  14901. @code{@@ACL} maps to the printer's requesting-user-name-allowed or
  14902. requesting-user-name-denied values. @code{@@OWNER} maps to the job's
  14903. owner. @code{@@SYSTEM} maps to the groups listed for the
  14904. @code{system-group} field of the @code{files-config} configuration,
  14905. which is reified into the @code{cups-files.conf(5)} file. Other
  14906. possible elements of the access list include specific user names, and
  14907. @code{@@@var{group}} to indicate members of a specific group. The
  14908. access list may also be simply @code{all} or @code{default}.
  14909. Defaults to @samp{"@@OWNER @@SYSTEM"}.
  14910. @end deftypevr
  14911. @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
  14912. Specifies the list of job values to make private, or @code{all},
  14913. @code{default}, or @code{none}.
  14914. Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
  14915. notify-subscriber-user-name notify-user-data"}.
  14916. @end deftypevr
  14917. @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
  14918. Access control by IPP operation.
  14919. Defaults to @samp{()}.
  14920. @end deftypevr
  14921. @end deftypevr
  14922. @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
  14923. Specifies whether job files (documents) are preserved after a job is
  14924. printed. If a numeric value is specified, job files are preserved for
  14925. the indicated number of seconds after printing. Otherwise a boolean
  14926. value applies indefinitely.
  14927. Defaults to @samp{86400}.
  14928. @end deftypevr
  14929. @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
  14930. Specifies whether the job history is preserved after a job is printed.
  14931. If a numeric value is specified, the job history is preserved for the
  14932. indicated number of seconds after printing. If @code{#t}, the job
  14933. history is preserved until the MaxJobs limit is reached.
  14934. Defaults to @samp{#t}.
  14935. @end deftypevr
  14936. @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
  14937. Specifies the amount of time to wait for job completion before
  14938. restarting the scheduler.
  14939. Defaults to @samp{30}.
  14940. @end deftypevr
  14941. @deftypevr {@code{cups-configuration} parameter} string rip-cache
  14942. Specifies the maximum amount of memory to use when converting documents
  14943. into bitmaps for a printer.
  14944. Defaults to @samp{"128m"}.
  14945. @end deftypevr
  14946. @deftypevr {@code{cups-configuration} parameter} string server-admin
  14947. Specifies the email address of the server administrator.
  14948. Defaults to @samp{"root@@localhost.localdomain"}.
  14949. @end deftypevr
  14950. @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
  14951. The ServerAlias directive is used for HTTP Host header validation when
  14952. clients connect to the scheduler from external interfaces. Using the
  14953. special name @code{*} can expose your system to known browser-based DNS
  14954. rebinding attacks, even when accessing sites through a firewall. If the
  14955. auto-discovery of alternate names does not work, we recommend listing
  14956. each alternate name with a ServerAlias directive instead of using
  14957. @code{*}.
  14958. Defaults to @samp{*}.
  14959. @end deftypevr
  14960. @deftypevr {@code{cups-configuration} parameter} string server-name
  14961. Specifies the fully-qualified host name of the server.
  14962. Defaults to @samp{"localhost"}.
  14963. @end deftypevr
  14964. @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
  14965. Specifies what information is included in the Server header of HTTP
  14966. responses. @code{None} disables the Server header. @code{ProductOnly}
  14967. reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
  14968. reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
  14969. @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
  14970. the output of the @code{uname} command. @code{Full} reports @code{CUPS
  14971. 2.0.0 (@var{uname}) IPP/2.0}.
  14972. Defaults to @samp{Minimal}.
  14973. @end deftypevr
  14974. @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
  14975. Listens on the specified interfaces for encrypted connections. Valid
  14976. values are of the form @var{address}:@var{port}, where @var{address} is
  14977. either an IPv6 address enclosed in brackets, an IPv4 address, or
  14978. @code{*} to indicate all addresses.
  14979. Defaults to @samp{()}.
  14980. @end deftypevr
  14981. @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
  14982. Sets encryption options. By default, CUPS only supports encryption
  14983. using TLS v1.0 or higher using known secure cipher suites. Security is
  14984. reduced when @code{Allow} options are used, and enhanced when @code{Deny}
  14985. options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
  14986. suites, which are required for some older clients. The @code{AllowSSL3} option
  14987. enables SSL v3.0, which is required for some older clients that do not support
  14988. TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
  14989. @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
  14990. protocol version to TLS v1.1.
  14991. Defaults to @samp{()}.
  14992. @end deftypevr
  14993. @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
  14994. Specifies whether the scheduler requires clients to strictly adhere to
  14995. the IPP specifications.
  14996. Defaults to @samp{#f}.
  14997. @end deftypevr
  14998. @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
  14999. Specifies the HTTP request timeout, in seconds.
  15000. Defaults to @samp{300}.
  15001. @end deftypevr
  15002. @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
  15003. Specifies whether the web interface is enabled.
  15004. Defaults to @samp{#f}.
  15005. @end deftypevr
  15006. At this point you're probably thinking ``oh dear, Guix manual, I like
  15007. you but you can stop already with the configuration options''. Indeed.
  15008. However, one more point: it could be that you have an existing
  15009. @code{cupsd.conf} that you want to use. In that case, you can pass an
  15010. @code{opaque-cups-configuration} as the configuration of a
  15011. @code{cups-service-type}.
  15012. Available @code{opaque-cups-configuration} fields are:
  15013. @deftypevr {@code{opaque-cups-configuration} parameter} package cups
  15014. The CUPS package.
  15015. @end deftypevr
  15016. @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
  15017. The contents of the @code{cupsd.conf}, as a string.
  15018. @end deftypevr
  15019. @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
  15020. The contents of the @code{cups-files.conf} file, as a string.
  15021. @end deftypevr
  15022. For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
  15023. strings of the same name, you could instantiate a CUPS service like
  15024. this:
  15025. @lisp
  15026. (service cups-service-type
  15027. (opaque-cups-configuration
  15028. (cupsd.conf cupsd.conf)
  15029. (cups-files.conf cups-files.conf)))
  15030. @end lisp
  15031. @node Desktop Services
  15032. @subsection Desktop Services
  15033. The @code{(gnu services desktop)} module provides services that are
  15034. usually useful in the context of a ``desktop'' setup---that is, on a
  15035. machine running a graphical display server, possibly with graphical user
  15036. interfaces, etc. It also defines services that provide specific desktop
  15037. environments like GNOME, Xfce or MATE.
  15038. To simplify things, the module defines a variable containing the set of
  15039. services that users typically expect on a machine with a graphical
  15040. environment and networking:
  15041. @defvr {Scheme Variable} %desktop-services
  15042. This is a list of services that builds upon @code{%base-services} and
  15043. adds or adjusts services for a typical ``desktop'' setup.
  15044. In particular, it adds a graphical login manager (@pxref{X Window,
  15045. @code{gdm-service-type}}), screen lockers, a network management tool
  15046. (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
  15047. support (@pxref{Networking Services, @code{modem-manager-service-type}}),
  15048. energy and color management services, the @code{elogind} login and seat
  15049. manager, the Polkit privilege service, the GeoClue location service, the
  15050. AccountsService daemon that allows authorized users change system passwords,
  15051. an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
  15052. name service switch service configured to be able to use @code{nss-mdns}
  15053. (@pxref{Name Service Switch, mDNS}).
  15054. @end defvr
  15055. The @code{%desktop-services} variable can be used as the @code{services}
  15056. field of an @code{operating-system} declaration (@pxref{operating-system
  15057. Reference, @code{services}}).
  15058. Additionally, the @code{gnome-desktop-service-type},
  15059. @code{xfce-desktop-service}, @code{mate-desktop-service-type},
  15060. @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
  15061. procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
  15062. ``add GNOME'' means that system-level services like the backlight adjustment
  15063. helpers and the power management utilities are added to the system, extending
  15064. @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
  15065. elevated privileges on a limited number of special-purpose system interfaces.
  15066. Additionally, adding a service made by @code{gnome-desktop-service-type} adds
  15067. the GNOME metapackage to the system profile. Likewise, adding the Xfce
  15068. service not only adds the @code{xfce} metapackage to the system profile, but
  15069. it also gives the Thunar file manager the ability to open a ``root-mode'' file
  15070. management window, if the user authenticates using the administrator's
  15071. password via the standard polkit graphical interface. To ``add MATE'' means
  15072. that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
  15073. to operate with elevated privileges on a limited number of special-purpose
  15074. system interfaces. Additionally, adding a service of type
  15075. @code{mate-desktop-service-type} adds the MATE metapackage to the system
  15076. profile. ``Adding Enlightenment'' means that @code{dbus} is extended
  15077. appropriately, and several of Enlightenment's binaries are set as setuid,
  15078. allowing Enlightenment's screen locker and other functionality to work as
  15079. expected.
  15080. The desktop environments in Guix use the Xorg display server by
  15081. default. If you'd like to use the newer display server protocol
  15082. called Wayland, you need to use the @code{sddm-service} instead of
  15083. GDM as the graphical login manager. You should then
  15084. select the ``GNOME (Wayland)'' session in SDDM@. Alternatively you can
  15085. also try starting GNOME on Wayland manually from a TTY with the
  15086. command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
  15087. gnome-session``. Currently only GNOME has support for Wayland.
  15088. @defvr {Scheme Variable} gnome-desktop-service-type
  15089. This is the type of the service that adds the @uref{https://www.gnome.org,
  15090. GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
  15091. object (see below).
  15092. This service adds the @code{gnome} package to the system profile, and extends
  15093. polkit with the actions from @code{gnome-settings-daemon}.
  15094. @end defvr
  15095. @deftp {Data Type} gnome-desktop-configuration
  15096. Configuration record for the GNOME desktop environment.
  15097. @table @asis
  15098. @item @code{gnome} (default: @code{gnome})
  15099. The GNOME package to use.
  15100. @end table
  15101. @end deftp
  15102. @defvr {Scheme Variable} xfce-desktop-service-type
  15103. This is the type of a service to run the @uref{Xfce, https://xfce.org/}
  15104. desktop environment. Its value is an @code{xfce-desktop-configuration} object
  15105. (see below).
  15106. This service adds the @code{xfce} package to the system profile, and
  15107. extends polkit with the ability for @code{thunar} to manipulate the file
  15108. system as root from within a user session, after the user has authenticated
  15109. with the administrator's password.
  15110. Note that @code{xfce4-panel} and its plugin packages should be installed in
  15111. the same profile to ensure compatibility. When using this service, you should
  15112. add extra plugins (@code{xfce4-whiskermenu-plugin},
  15113. @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
  15114. @code{operating-system}.
  15115. @end defvr
  15116. @deftp {Data Type} xfce-desktop-configuration
  15117. Configuration record for the Xfce desktop environment.
  15118. @table @asis
  15119. @item @code{xfce} (default: @code{xfce})
  15120. The Xfce package to use.
  15121. @end table
  15122. @end deftp
  15123. @deffn {Scheme Variable} mate-desktop-service-type
  15124. This is the type of the service that runs the @uref{https://mate-desktop.org/,
  15125. MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
  15126. object (see below).
  15127. This service adds the @code{mate} package to the system
  15128. profile, and extends polkit with the actions from
  15129. @code{mate-settings-daemon}.
  15130. @end deffn
  15131. @deftp {Data Type} mate-desktop-configuration
  15132. Configuration record for the MATE desktop environment.
  15133. @table @asis
  15134. @item @code{mate} (default: @code{mate})
  15135. The MATE package to use.
  15136. @end table
  15137. @end deftp
  15138. @deffn {Scheme Variable} lxqt-desktop-service-type
  15139. This is the type of the service that runs the @uref{https://lxqt.github.io,
  15140. LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
  15141. object (see below).
  15142. This service adds the @code{lxqt} package to the system
  15143. profile.
  15144. @end deffn
  15145. @deftp {Data Type} lxqt-desktop-configuration
  15146. Configuration record for the LXQt desktop environment.
  15147. @table @asis
  15148. @item @code{lxqt} (default: @code{lxqt})
  15149. The LXQT package to use.
  15150. @end table
  15151. @end deftp
  15152. @deffn {Scheme Variable} enlightenment-desktop-service-type
  15153. Return a service that adds the @code{enlightenment} package to the system
  15154. profile, and extends dbus with actions from @code{efl}.
  15155. @end deffn
  15156. @deftp {Data Type} enlightenment-desktop-service-configuration
  15157. @table @asis
  15158. @item @code{enlightenment} (default: @code{enlightenment})
  15159. The enlightenment package to use.
  15160. @end table
  15161. @end deftp
  15162. Because the GNOME, Xfce and MATE desktop services pull in so many packages,
  15163. the default @code{%desktop-services} variable doesn't include any of
  15164. them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
  15165. @code{%desktop-services} in the @code{services} field of your
  15166. @code{operating-system}:
  15167. @lisp
  15168. (use-modules (gnu))
  15169. (use-service-modules desktop)
  15170. (operating-system
  15171. ...
  15172. ;; cons* adds items to the list given as its last argument.
  15173. (services (cons* (service gnome-desktop-service-type)
  15174. (service xfce-desktop-service)
  15175. %desktop-services))
  15176. ...)
  15177. @end lisp
  15178. These desktop environments will then be available as options in the
  15179. graphical login window.
  15180. The actual service definitions included in @code{%desktop-services} and
  15181. provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
  15182. are described below.
  15183. @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
  15184. Return a service that runs the ``system bus'', using @var{dbus}, with
  15185. support for @var{services}.
  15186. @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
  15187. facility. Its system bus is used to allow system services to communicate
  15188. and to be notified of system-wide events.
  15189. @var{services} must be a list of packages that provide an
  15190. @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
  15191. and policy files. For example, to allow avahi-daemon to use the system bus,
  15192. @var{services} must be equal to @code{(list avahi)}.
  15193. @end deffn
  15194. @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
  15195. Return a service that runs the @code{elogind} login and
  15196. seat management daemon. @uref{https://github.com/elogind/elogind,
  15197. Elogind} exposes a D-Bus interface that can be used to know which users
  15198. are logged in, know what kind of sessions they have open, suspend the
  15199. system, inhibit system suspend, reboot the system, and other tasks.
  15200. Elogind handles most system-level power events for a computer, for
  15201. example suspending the system when a lid is closed, or shutting it down
  15202. when the power button is pressed.
  15203. The @var{config} keyword argument specifies the configuration for
  15204. elogind, and should be the result of an @code{(elogind-configuration
  15205. (@var{parameter} @var{value})...)} invocation. Available parameters and
  15206. their default values are:
  15207. @table @code
  15208. @item kill-user-processes?
  15209. @code{#f}
  15210. @item kill-only-users
  15211. @code{()}
  15212. @item kill-exclude-users
  15213. @code{("root")}
  15214. @item inhibit-delay-max-seconds
  15215. @code{5}
  15216. @item handle-power-key
  15217. @code{poweroff}
  15218. @item handle-suspend-key
  15219. @code{suspend}
  15220. @item handle-hibernate-key
  15221. @code{hibernate}
  15222. @item handle-lid-switch
  15223. @code{suspend}
  15224. @item handle-lid-switch-docked
  15225. @code{ignore}
  15226. @item handle-lid-switch-external-power
  15227. @code{ignore}
  15228. @item power-key-ignore-inhibited?
  15229. @code{#f}
  15230. @item suspend-key-ignore-inhibited?
  15231. @code{#f}
  15232. @item hibernate-key-ignore-inhibited?
  15233. @code{#f}
  15234. @item lid-switch-ignore-inhibited?
  15235. @code{#t}
  15236. @item holdoff-timeout-seconds
  15237. @code{30}
  15238. @item idle-action
  15239. @code{ignore}
  15240. @item idle-action-seconds
  15241. @code{(* 30 60)}
  15242. @item runtime-directory-size-percent
  15243. @code{10}
  15244. @item runtime-directory-size
  15245. @code{#f}
  15246. @item remove-ipc?
  15247. @code{#t}
  15248. @item suspend-state
  15249. @code{("mem" "standby" "freeze")}
  15250. @item suspend-mode
  15251. @code{()}
  15252. @item hibernate-state
  15253. @code{("disk")}
  15254. @item hibernate-mode
  15255. @code{("platform" "shutdown")}
  15256. @item hybrid-sleep-state
  15257. @code{("disk")}
  15258. @item hybrid-sleep-mode
  15259. @code{("suspend" "platform" "shutdown")}
  15260. @end table
  15261. @end deffn
  15262. @deffn {Scheme Procedure} accountsservice-service @
  15263. [#:accountsservice @var{accountsservice}]
  15264. Return a service that runs AccountsService, a system service that can
  15265. list available accounts, change their passwords, and so on.
  15266. AccountsService integrates with PolicyKit to enable unprivileged users
  15267. to acquire the capability to modify their system configuration.
  15268. @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
  15269. accountsservice web site} for more information.
  15270. The @var{accountsservice} keyword argument is the @code{accountsservice}
  15271. package to expose as a service.
  15272. @end deffn
  15273. @deffn {Scheme Procedure} polkit-service @
  15274. [#:polkit @var{polkit}]
  15275. Return a service that runs the
  15276. @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
  15277. management service}, which allows system administrators to grant access to
  15278. privileged operations in a structured way. By querying the Polkit service, a
  15279. privileged system component can know when it should grant additional
  15280. capabilities to ordinary users. For example, an ordinary user can be granted
  15281. the capability to suspend the system if the user is logged in locally.
  15282. @end deffn
  15283. @defvr {Scheme Variable} polkit-wheel-service
  15284. Service that adds the @code{wheel} group as admins to the Polkit
  15285. service. This makes it so that users in the @code{wheel} group are queried
  15286. for their own passwords when performing administrative actions instead of
  15287. @code{root}'s, similar to the behaviour used by @code{sudo}.
  15288. @end defvr
  15289. @defvr {Scheme Variable} upower-service-type
  15290. Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
  15291. system-wide monitor for power consumption and battery levels, with the given
  15292. configuration settings.
  15293. It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
  15294. notably used by GNOME.
  15295. @end defvr
  15296. @deftp {Data Type} upower-configuration
  15297. Data type representation the configuration for UPower.
  15298. @table @asis
  15299. @item @code{upower} (default: @var{upower})
  15300. Package to use for @code{upower}.
  15301. @item @code{watts-up-pro?} (default: @code{#f})
  15302. Enable the Watts Up Pro device.
  15303. @item @code{poll-batteries?} (default: @code{#t})
  15304. Enable polling the kernel for battery level changes.
  15305. @item @code{ignore-lid?} (default: @code{#f})
  15306. Ignore the lid state, this can be useful if it's incorrect on a device.
  15307. @item @code{use-percentage-for-policy?} (default: @code{#f})
  15308. Whether battery percentage based policy should be used. The default is to use
  15309. the time left, change to @code{#t} to use the percentage.
  15310. @item @code{percentage-low} (default: @code{10})
  15311. When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
  15312. at which the battery is considered low.
  15313. @item @code{percentage-critical} (default: @code{3})
  15314. When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
  15315. at which the battery is considered critical.
  15316. @item @code{percentage-action} (default: @code{2})
  15317. When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
  15318. at which action will be taken.
  15319. @item @code{time-low} (default: @code{1200})
  15320. When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
  15321. seconds at which the battery is considered low.
  15322. @item @code{time-critical} (default: @code{300})
  15323. When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
  15324. seconds at which the battery is considered critical.
  15325. @item @code{time-action} (default: @code{120})
  15326. When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
  15327. seconds at which action will be taken.
  15328. @item @code{critical-power-action} (default: @code{'hybrid-sleep})
  15329. The action taken when @code{percentage-action} or @code{time-action} is
  15330. reached (depending on the configuration of @code{use-percentage-for-policy?}).
  15331. Possible values are:
  15332. @itemize @bullet
  15333. @item
  15334. @code{'power-off}
  15335. @item
  15336. @code{'hibernate}
  15337. @item
  15338. @code{'hybrid-sleep}.
  15339. @end itemize
  15340. @end table
  15341. @end deftp
  15342. @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
  15343. Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
  15344. UDisks}, a @dfn{disk management} daemon that provides user interfaces
  15345. with notifications and ways to mount/unmount disks. Programs that talk
  15346. to UDisks include the @command{udisksctl} command, part of UDisks, and
  15347. GNOME Disks. Note that Udisks relies on the @command{mount} command, so
  15348. it will only be able to use the file-system utilities installed in the
  15349. system profile. For example if you want to be able to mount NTFS
  15350. file-systems in read and write fashion, you'll need to have
  15351. @code{ntfs-3g} installed system-wide.
  15352. @end deffn
  15353. @deffn {Scheme Variable} colord-service-type
  15354. This is the type of the service that runs @command{colord}, a system
  15355. service with a D-Bus
  15356. interface to manage the color profiles of input and output devices such as
  15357. screens and scanners. It is notably used by the GNOME Color Manager graphical
  15358. tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
  15359. site} for more information.
  15360. @end deffn
  15361. @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
  15362. Return a configuration allowing an application to access GeoClue
  15363. location data. @var{name} is the Desktop ID of the application, without
  15364. the @code{.desktop} part. If @var{allowed?} is true, the application
  15365. will have access to location information by default. The boolean
  15366. @var{system?} value indicates whether an application is a system component
  15367. or not. Finally @var{users} is a list of UIDs of all users for which
  15368. this application is allowed location info access. An empty users list
  15369. means that all users are allowed.
  15370. @end deffn
  15371. @cindex scanner access
  15372. @deffn {Scheme Procedure} sane-service-type
  15373. This service provides access to scanners @i{via}
  15374. @uref{http://www.sane-project.org, SANE} by installing the necessary udev
  15375. rules.
  15376. @end deffn
  15377. @defvr {Scheme Variable} %standard-geoclue-applications
  15378. The standard list of well-known GeoClue application configurations,
  15379. granting authority to the GNOME date-and-time utility to ask for the
  15380. current location in order to set the time zone, and allowing the
  15381. IceCat and Epiphany web browsers to request location information.
  15382. IceCat and Epiphany both query the user before allowing a web page to
  15383. know the user's location.
  15384. @end defvr
  15385. @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
  15386. [#:whitelist '()] @
  15387. [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
  15388. [#:submit-data? #f]
  15389. [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
  15390. [#:submission-nick "geoclue"] @
  15391. [#:applications %standard-geoclue-applications]
  15392. Return a service that runs the GeoClue location service. This service
  15393. provides a D-Bus interface to allow applications to request access to a
  15394. user's physical location, and optionally to add information to online
  15395. location databases. See
  15396. @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
  15397. web site} for more information.
  15398. @end deffn
  15399. @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
  15400. [@w{#:auto-enable? #f}]
  15401. Return a service that runs the @command{bluetoothd} daemon, which
  15402. manages all the Bluetooth devices and provides a number of D-Bus
  15403. interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
  15404. powered automatically at boot, which can be useful when using a
  15405. bluetooth keyboard or mouse.
  15406. Users need to be in the @code{lp} group to access the D-Bus service.
  15407. @end deffn
  15408. @defvr {Scheme Variable} gnome-keyring-service-type
  15409. This is the type of the service that adds the
  15410. @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
  15411. value is a @code{gnome-keyring-configuration} object (see below).
  15412. This service adds the @code{gnome-keyring} package to the system profile
  15413. and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
  15414. a user's login keyring when they log in or setting its password with passwd.
  15415. @end defvr
  15416. @deftp {Data Type} gnome-keyring-configuration
  15417. Configuration record for the GNOME Keyring service.
  15418. @table @asis
  15419. @item @code{keyring} (default: @code{gnome-keyring})
  15420. The GNOME keyring package to use.
  15421. @item @code{pam-services}
  15422. A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
  15423. services to extend, where @var{service} is the name of an existing
  15424. service to extend and @var{kind} is one of @code{login} or
  15425. @code{passwd}.
  15426. If @code{login} is given, it adds an optional
  15427. @code{pam_gnome_keyring.so} to the auth block without arguments and to
  15428. the session block with @code{auto_start}. If @code{passwd} is given, it
  15429. adds an optional @code{pam_gnome_keyring.so} to the password block
  15430. without arguments.
  15431. By default, this field contains ``gdm-password'' with the value @code{login}
  15432. and ``passwd'' is with the value @code{passwd}.
  15433. @end table
  15434. @end deftp
  15435. @node Sound Services
  15436. @subsection Sound Services
  15437. @cindex sound support
  15438. @cindex ALSA
  15439. @cindex PulseAudio, sound support
  15440. The @code{(gnu services sound)} module provides a service to configure the
  15441. Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
  15442. preferred ALSA output driver.
  15443. @deffn {Scheme Variable} alsa-service-type
  15444. This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
  15445. Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
  15446. configuration file. The value for this type is a @command{alsa-configuration}
  15447. record as in this example:
  15448. @lisp
  15449. (service alsa-service-type)
  15450. @end lisp
  15451. See below for details about @code{alsa-configuration}.
  15452. @end deffn
  15453. @deftp {Data Type} alsa-configuration
  15454. Data type representing the configuration for @code{alsa-service}.
  15455. @table @asis
  15456. @item @code{alsa-plugins} (default: @var{alsa-plugins})
  15457. @code{alsa-plugins} package to use.
  15458. @item @code{pulseaudio?} (default: @var{#t})
  15459. Whether ALSA applications should transparently be made to use the
  15460. @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
  15461. Using PulseAudio allows you to run several sound-producing applications
  15462. at the same time and to individual control them @i{via}
  15463. @command{pavucontrol}, among other things.
  15464. @item @code{extra-options} (default: @var{""})
  15465. String to append to the @file{/etc/asound.conf} file.
  15466. @end table
  15467. @end deftp
  15468. Individual users who want to override the system configuration of ALSA can do
  15469. it with the @file{~/.asoundrc} file:
  15470. @example
  15471. # In guix, we have to specify the absolute path for plugins.
  15472. pcm_type.jack @{
  15473. lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
  15474. @}
  15475. # Routing ALSA to jack:
  15476. # <http://jackaudio.org/faq/routing_alsa.html>.
  15477. pcm.rawjack @{
  15478. type jack
  15479. playback_ports @{
  15480. 0 system:playback_1
  15481. 1 system:playback_2
  15482. @}
  15483. capture_ports @{
  15484. 0 system:capture_1
  15485. 1 system:capture_2
  15486. @}
  15487. @}
  15488. pcm.!default @{
  15489. type plug
  15490. slave @{
  15491. pcm "rawjack"
  15492. @}
  15493. @}
  15494. @end example
  15495. See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
  15496. details.
  15497. @deffn {Scheme Variable} pulseaudio-service-type
  15498. This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
  15499. sound server. It exists to allow system overrides of the default settings
  15500. via @code{pulseaudio-configuration}, see below.
  15501. @quotation Warning
  15502. This service overrides per-user configuration files. If you want
  15503. PulseAudio to honor configuration files in @file{~/.config/pulse} you
  15504. have to unset the environment variables @env{PULSE_CONFIG} and
  15505. @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
  15506. @end quotation
  15507. @quotation Warning
  15508. This service on its own does not ensure, that the @code{pulseaudio} package
  15509. exists on your machine. It merely adds configuration files for it, as
  15510. detailed below. In the (admittedly unlikely) case, that you find yourself
  15511. without a @code{pulseaudio} package, consider enabling it through the
  15512. @code{alsa-service-type} above.
  15513. @end quotation
  15514. @end deffn
  15515. @deftp {Data Type} pulseaudio-configuration
  15516. Data type representing the configuration for @code{pulseaudio-service}.
  15517. @table @asis
  15518. @item @code{client-conf} (default: @code{'()})
  15519. List of settings to set in @file{client.conf}.
  15520. Accepts a list of strings or a symbol-value pairs. A string will be
  15521. inserted as-is with a newline added. A pair will be formatted as
  15522. ``key = value'', again with a newline added.
  15523. @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
  15524. List of settings to set in @file{daemon.conf}, formatted just like
  15525. @var{client-conf}.
  15526. @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
  15527. Script file to use as @file{default.pa}.
  15528. @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
  15529. Script file to use as @file{system.pa}.
  15530. @end table
  15531. @end deftp
  15532. @deffn {Scheme Variable} ladspa-service-type
  15533. This service sets the @var{LADSPA_PATH} variable, so that programs, which
  15534. respect it, e.g. PulseAudio, can load LADSPA plugins.
  15535. The following example will setup the service to enable modules from the
  15536. @code{swh-plugins} package:
  15537. @lisp
  15538. (service ladspa-service-type
  15539. (ladspa-configuration (plugins (list swh-plugins))))
  15540. @end lisp
  15541. See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
  15542. details.
  15543. @end deffn
  15544. @node Database Services
  15545. @subsection Database Services
  15546. @cindex database
  15547. @cindex SQL
  15548. The @code{(gnu services databases)} module provides the following services.
  15549. @subsubheading PostgreSQL
  15550. The following example describes a PostgreSQL service with the default
  15551. configuration.
  15552. @lisp
  15553. (service postgresql-service-type
  15554. (postgresql-configuration
  15555. (postgresql postgresql-10)))
  15556. @end lisp
  15557. If the services fails to start, it may be due to an incompatible
  15558. cluster already present in @var{data-directory}. Adjust it (or, if you
  15559. don't need the cluster anymore, delete @var{data-directory}), then
  15560. restart the service.
  15561. Peer authentication is used by default and the @code{postgres} user
  15562. account has no shell, which prevents the direct execution of @code{psql}
  15563. commands as this user. To use @code{psql}, you can temporarily log in
  15564. as @code{postgres} using a shell, create a PostgreSQL superuser with the
  15565. same name as one of the system users and then create the associated
  15566. database.
  15567. @example
  15568. sudo -u postgres -s /bin/sh
  15569. createuser --interactive
  15570. createdb $MY_USER_LOGIN # Replace appropriately.
  15571. @end example
  15572. @deftp {Data Type} postgresql-configuration
  15573. Data type representing the configuration for the
  15574. @code{postgresql-service-type}.
  15575. @table @asis
  15576. @item @code{postgresql}
  15577. PostgreSQL package to use for the service.
  15578. @item @code{port} (default: @code{5432})
  15579. Port on which PostgreSQL should listen.
  15580. @item @code{locale} (default: @code{"en_US.utf8"})
  15581. Locale to use as the default when creating the database cluster.
  15582. @item @code{config-file} (default: @code{(postgresql-config-file)})
  15583. The configuration file to use when running PostgreSQL@. The default
  15584. behaviour uses the postgresql-config-file record with the default values
  15585. for the fields.
  15586. @item @code{log-directory} (default: @code{"/var/log/postgresql"})
  15587. The directory where @command{pg_ctl} output will be written in a file
  15588. named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
  15589. configuration errors for instance.
  15590. @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
  15591. Directory in which to store the data.
  15592. @item @code{extension-packages} (default: @code{'()})
  15593. @cindex postgresql extension-packages
  15594. Additional extensions are loaded from packages listed in
  15595. @var{extension-packages}. Extensions are available at runtime. For instance,
  15596. to create a geographic database using the @code{postgis} extension, a user can
  15597. configure the postgresql-service as in this example:
  15598. @cindex postgis
  15599. @lisp
  15600. (use-package-modules databases geo)
  15601. (operating-system
  15602. ...
  15603. ;; postgresql is required to run `psql' but postgis is not required for
  15604. ;; proper operation.
  15605. (packages (cons* postgresql %base-packages))
  15606. (services
  15607. (cons*
  15608. (service postgresql-service-type
  15609. (postgresql-configuration
  15610. (postgresql postgresql-10)
  15611. (extension-packages (list postgis))))
  15612. %base-services)))
  15613. @end lisp
  15614. Then the extension becomes visible and you can initialise an empty geographic
  15615. database in this way:
  15616. @example
  15617. psql -U postgres
  15618. > create database postgistest;
  15619. > \connect postgistest;
  15620. > create extension postgis;
  15621. > create extension postgis_topology;
  15622. @end example
  15623. There is no need to add this field for contrib extensions such as hstore or
  15624. dblink as they are already loadable by postgresql. This field is only
  15625. required to add extensions provided by other packages.
  15626. @end table
  15627. @end deftp
  15628. @deftp {Data Type} postgresql-config-file
  15629. Data type representing the PostgreSQL configuration file. As shown in
  15630. the following example, this can be used to customize the configuration
  15631. of PostgreSQL@. Note that you can use any G-expression or filename in
  15632. place of this record, if you already have a configuration file you'd
  15633. like to use for example.
  15634. @lisp
  15635. (service postgresql-service-type
  15636. (postgresql-configuration
  15637. (config-file
  15638. (postgresql-config-file
  15639. (log-destination "stderr")
  15640. (hba-file
  15641. (plain-file "pg_hba.conf"
  15642. "
  15643. local all all trust
  15644. host all all 127.0.0.1/32 md5
  15645. host all all ::1/128 md5"))
  15646. (extra-config
  15647. '(("session_preload_libraries" "auto_explain")
  15648. ("random_page_cost" 2)
  15649. ("auto_explain.log_min_duration" "100 ms")
  15650. ("work_mem" "500 MB")
  15651. ("logging_collector" #t)
  15652. ("log_directory" "/var/log/postgresql")))))))
  15653. @end lisp
  15654. @table @asis
  15655. @item @code{log-destination} (default: @code{"syslog"})
  15656. The logging method to use for PostgreSQL@. Multiple values are accepted,
  15657. separated by commas.
  15658. @item @code{hba-file} (default: @code{%default-postgres-hba})
  15659. Filename or G-expression for the host-based authentication
  15660. configuration.
  15661. @item @code{ident-file} (default: @code{%default-postgres-ident})
  15662. Filename or G-expression for the user name mapping configuration.
  15663. @item @code{socket-directory} (default: @code{"/var/lib/postgresql"})
  15664. Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
  15665. is to listen for connections from client applications. If set to
  15666. @code{#false} PostgreSQL does not listen on any Unix-domain sockets, in
  15667. which case only TCP/IP sockets can be used to connect to the server.
  15668. @item @code{extra-config} (default: @code{'()})
  15669. List of additional keys and values to include in the PostgreSQL config
  15670. file. Each entry in the list should be a list where the first element
  15671. is the key, and the remaining elements are the values.
  15672. The values can be numbers, booleans or strings and will be mapped to
  15673. PostgreSQL parameters types @code{Boolean}, @code{String},
  15674. @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
  15675. @uref{https://www.postgresql.org/docs/current/config-setting.html,
  15676. here}.
  15677. @end table
  15678. @end deftp
  15679. @deffn {Scheme Variable} postgresql-role-service-type
  15680. This service allows to create PostgreSQL roles and databases after
  15681. PostgreSQL service start. Here is an example of its use.
  15682. @lisp
  15683. (service postgresql-role-service-type
  15684. (postgresql-role-configuration
  15685. (roles
  15686. (list (postgresql-role
  15687. (name "test")
  15688. (create-database? #t))))))
  15689. @end lisp
  15690. This service can be extended with extra roles, as in this
  15691. example:
  15692. @lisp
  15693. (service-extension postgresql-role-service-type
  15694. (const (postgresql-role
  15695. (name "alice")
  15696. (create-database? #t))))
  15697. @end lisp
  15698. @end deffn
  15699. @deftp {Data Type} postgresql-role
  15700. PostgreSQL manages database access permissions using the concept of
  15701. roles. A role can be thought of as either a database user, or a group
  15702. of database users, depending on how the role is set up. Roles can own
  15703. database objects (for example, tables) and can assign privileges on
  15704. those objects to other roles to control who has access to which objects.
  15705. @table @asis
  15706. @item @code{name}
  15707. The role name.
  15708. @item @code{permissions} (default: @code{'(createdb login)})
  15709. The role permissions list. Supported permissions are @code{bypassrls},
  15710. @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
  15711. @code{superuser}.
  15712. @item @code{create-database?} (default: @code{#f})
  15713. Whether to create a database with the same name as the role.
  15714. @end table
  15715. @end deftp
  15716. @deftp {Data Type} postgresql-role-configuration
  15717. Data type representing the configuration of
  15718. @var{postgresql-role-service-type}.
  15719. @table @asis
  15720. @item @code{host} (default: @code{"/var/run/postgresql"})
  15721. The PostgreSQL host to connect to.
  15722. @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
  15723. File name of the log file.
  15724. @item @code{roles} (default: @code{'()})
  15725. The initial PostgreSQL roles to create.
  15726. @end table
  15727. @end deftp
  15728. @subsubheading MariaDB/MySQL
  15729. @defvr {Scheme Variable} mysql-service-type
  15730. This is the service type for a MySQL or MariaDB database server. Its value
  15731. is a @code{mysql-configuration} object that specifies which package to use,
  15732. as well as various settings for the @command{mysqld} daemon.
  15733. @end defvr
  15734. @deftp {Data Type} mysql-configuration
  15735. Data type representing the configuration of @var{mysql-service-type}.
  15736. @table @asis
  15737. @item @code{mysql} (default: @var{mariadb})
  15738. Package object of the MySQL database server, can be either @var{mariadb}
  15739. or @var{mysql}.
  15740. For MySQL, a temporary root password will be displayed at activation time.
  15741. For MariaDB, the root password is empty.
  15742. @item @code{bind-address} (default: @code{"127.0.0.1"})
  15743. The IP on which to listen for network connections. Use @code{"0.0.0.0"}
  15744. to bind to all available network interfaces.
  15745. @item @code{port} (default: @code{3306})
  15746. TCP port on which the database server listens for incoming connections.
  15747. @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
  15748. Socket file to use for local (non-network) connections.
  15749. @item @code{extra-content} (default: @code{""})
  15750. Additional settings for the @file{my.cnf} configuration file.
  15751. @item @code{auto-upgrade?} (default: @code{#t})
  15752. Whether to automatically run @command{mysql_upgrade} after starting the
  15753. service. This is necessary to upgrade the @dfn{system schema} after
  15754. ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
  15755. be disabled if you would rather do that manually.
  15756. @end table
  15757. @end deftp
  15758. @subsubheading Memcached
  15759. @defvr {Scheme Variable} memcached-service-type
  15760. This is the service type for the @uref{https://memcached.org/,
  15761. Memcached} service, which provides a distributed in memory cache. The
  15762. value for the service type is a @code{memcached-configuration} object.
  15763. @end defvr
  15764. @lisp
  15765. (service memcached-service-type)
  15766. @end lisp
  15767. @deftp {Data Type} memcached-configuration
  15768. Data type representing the configuration of memcached.
  15769. @table @asis
  15770. @item @code{memcached} (default: @code{memcached})
  15771. The Memcached package to use.
  15772. @item @code{interfaces} (default: @code{'("0.0.0.0")})
  15773. Network interfaces on which to listen.
  15774. @item @code{tcp-port} (default: @code{11211})
  15775. Port on which to accept connections.
  15776. @item @code{udp-port} (default: @code{11211})
  15777. Port on which to accept UDP connections on, a value of 0 will disable
  15778. listening on a UDP socket.
  15779. @item @code{additional-options} (default: @code{'()})
  15780. Additional command line options to pass to @code{memcached}.
  15781. @end table
  15782. @end deftp
  15783. @subsubheading MongoDB
  15784. @defvr {Scheme Variable} mongodb-service-type
  15785. This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
  15786. The value for the service type is a @code{mongodb-configuration} object.
  15787. @end defvr
  15788. @lisp
  15789. (service mongodb-service-type)
  15790. @end lisp
  15791. @deftp {Data Type} mongodb-configuration
  15792. Data type representing the configuration of mongodb.
  15793. @table @asis
  15794. @item @code{mongodb} (default: @code{mongodb})
  15795. The MongoDB package to use.
  15796. @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
  15797. The configuration file for MongoDB.
  15798. @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
  15799. This value is used to create the directory, so that it exists and is
  15800. owned by the mongodb user. It should match the data-directory which
  15801. MongoDB is configured to use through the configuration file.
  15802. @end table
  15803. @end deftp
  15804. @subsubheading Redis
  15805. @defvr {Scheme Variable} redis-service-type
  15806. This is the service type for the @uref{https://redis.io/, Redis}
  15807. key/value store, whose value is a @code{redis-configuration} object.
  15808. @end defvr
  15809. @deftp {Data Type} redis-configuration
  15810. Data type representing the configuration of redis.
  15811. @table @asis
  15812. @item @code{redis} (default: @code{redis})
  15813. The Redis package to use.
  15814. @item @code{bind} (default: @code{"127.0.0.1"})
  15815. Network interface on which to listen.
  15816. @item @code{port} (default: @code{6379})
  15817. Port on which to accept connections on, a value of 0 will disable
  15818. listening on a TCP socket.
  15819. @item @code{working-directory} (default: @code{"/var/lib/redis"})
  15820. Directory in which to store the database and related files.
  15821. @end table
  15822. @end deftp
  15823. @node Mail Services
  15824. @subsection Mail Services
  15825. @cindex mail
  15826. @cindex email
  15827. The @code{(gnu services mail)} module provides Guix service definitions
  15828. for email services: IMAP, POP3, and LMTP servers, as well as mail
  15829. transport agents (MTAs). Lots of acronyms! These services are detailed
  15830. in the subsections below.
  15831. @subsubheading Dovecot Service
  15832. @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
  15833. Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
  15834. @end deffn
  15835. By default, Dovecot does not need much configuration; the default
  15836. configuration object created by @code{(dovecot-configuration)} will
  15837. suffice if your mail is delivered to @code{~/Maildir}. A self-signed
  15838. certificate will be generated for TLS-protected connections, though
  15839. Dovecot will also listen on cleartext ports by default. There are a
  15840. number of options, though, which mail administrators might need to change,
  15841. and as is the case with other services, Guix allows the system
  15842. administrator to specify these parameters via a uniform Scheme interface.
  15843. For example, to specify that mail is located at @code{maildir~/.mail},
  15844. one would instantiate the Dovecot service like this:
  15845. @lisp
  15846. (dovecot-service #:config
  15847. (dovecot-configuration
  15848. (mail-location "maildir:~/.mail")))
  15849. @end lisp
  15850. The available configuration parameters follow. Each parameter
  15851. definition is preceded by its type; for example, @samp{string-list foo}
  15852. indicates that the @code{foo} parameter should be specified as a list of
  15853. strings. There is also a way to specify the configuration as a string,
  15854. if you have an old @code{dovecot.conf} file that you want to port over
  15855. from some other system; see the end for more details.
  15856. @c The following documentation was initially generated by
  15857. @c (generate-documentation) in (gnu services mail). Manually maintained
  15858. @c documentation is better, so we shouldn't hesitate to edit below as
  15859. @c needed. However if the change you want to make to this documentation
  15860. @c can be done in an automated way, it's probably easier to change
  15861. @c (generate-documentation) than to make it below and have to deal with
  15862. @c the churn as dovecot updates.
  15863. Available @code{dovecot-configuration} fields are:
  15864. @deftypevr {@code{dovecot-configuration} parameter} package dovecot
  15865. The dovecot package.
  15866. @end deftypevr
  15867. @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
  15868. A list of IPs or hosts where to listen for connections. @samp{*}
  15869. listens on all IPv4 interfaces, @samp{::} listens on all IPv6
  15870. interfaces. If you want to specify non-default ports or anything more
  15871. complex, customize the address and port fields of the
  15872. @samp{inet-listener} of the specific services you are interested in.
  15873. @end deftypevr
  15874. @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
  15875. List of protocols we want to serve. Available protocols include
  15876. @samp{imap}, @samp{pop3}, and @samp{lmtp}.
  15877. Available @code{protocol-configuration} fields are:
  15878. @deftypevr {@code{protocol-configuration} parameter} string name
  15879. The name of the protocol.
  15880. @end deftypevr
  15881. @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
  15882. UNIX socket path to the master authentication server to find users.
  15883. This is used by imap (for shared users) and lda.
  15884. It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
  15885. @end deftypevr
  15886. @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
  15887. Space separated list of plugins to load.
  15888. @end deftypevr
  15889. @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
  15890. Maximum number of IMAP connections allowed for a user from each IP
  15891. address. NOTE: The username is compared case-sensitively.
  15892. Defaults to @samp{10}.
  15893. @end deftypevr
  15894. @end deftypevr
  15895. @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
  15896. List of services to enable. Available services include @samp{imap},
  15897. @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
  15898. @samp{lmtp}.
  15899. Available @code{service-configuration} fields are:
  15900. @deftypevr {@code{service-configuration} parameter} string kind
  15901. The service kind. Valid values include @code{director},
  15902. @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
  15903. @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
  15904. @code{tcpwrap}, @code{quota-warning}, or anything else.
  15905. @end deftypevr
  15906. @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
  15907. Listeners for the service. A listener is either a
  15908. @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
  15909. an @code{inet-listener-configuration}.
  15910. Defaults to @samp{()}.
  15911. Available @code{unix-listener-configuration} fields are:
  15912. @deftypevr {@code{unix-listener-configuration} parameter} string path
  15913. Path to the file, relative to @code{base-dir} field. This is also used as
  15914. the section name.
  15915. @end deftypevr
  15916. @deftypevr {@code{unix-listener-configuration} parameter} string mode
  15917. The access mode for the socket.
  15918. Defaults to @samp{"0600"}.
  15919. @end deftypevr
  15920. @deftypevr {@code{unix-listener-configuration} parameter} string user
  15921. The user to own the socket.
  15922. Defaults to @samp{""}.
  15923. @end deftypevr
  15924. @deftypevr {@code{unix-listener-configuration} parameter} string group
  15925. The group to own the socket.
  15926. Defaults to @samp{""}.
  15927. @end deftypevr
  15928. Available @code{fifo-listener-configuration} fields are:
  15929. @deftypevr {@code{fifo-listener-configuration} parameter} string path
  15930. Path to the file, relative to @code{base-dir} field. This is also used as
  15931. the section name.
  15932. @end deftypevr
  15933. @deftypevr {@code{fifo-listener-configuration} parameter} string mode
  15934. The access mode for the socket.
  15935. Defaults to @samp{"0600"}.
  15936. @end deftypevr
  15937. @deftypevr {@code{fifo-listener-configuration} parameter} string user
  15938. The user to own the socket.
  15939. Defaults to @samp{""}.
  15940. @end deftypevr
  15941. @deftypevr {@code{fifo-listener-configuration} parameter} string group
  15942. The group to own the socket.
  15943. Defaults to @samp{""}.
  15944. @end deftypevr
  15945. Available @code{inet-listener-configuration} fields are:
  15946. @deftypevr {@code{inet-listener-configuration} parameter} string protocol
  15947. The protocol to listen for.
  15948. @end deftypevr
  15949. @deftypevr {@code{inet-listener-configuration} parameter} string address
  15950. The address on which to listen, or empty for all addresses.
  15951. Defaults to @samp{""}.
  15952. @end deftypevr
  15953. @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
  15954. The port on which to listen.
  15955. @end deftypevr
  15956. @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
  15957. Whether to use SSL for this service; @samp{yes}, @samp{no}, or
  15958. @samp{required}.
  15959. Defaults to @samp{#t}.
  15960. @end deftypevr
  15961. @end deftypevr
  15962. @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
  15963. Maximum number of simultaneous client connections per process. Once
  15964. this number of connections is received, the next incoming connection
  15965. will prompt Dovecot to spawn another process. If set to 0,
  15966. @code{default-client-limit} is used instead.
  15967. Defaults to @samp{0}.
  15968. @end deftypevr
  15969. @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
  15970. Number of connections to handle before starting a new process.
  15971. Typically the only useful values are 0 (unlimited) or 1. 1 is more
  15972. secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
  15973. Defaults to @samp{1}.
  15974. @end deftypevr
  15975. @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
  15976. Maximum number of processes that can exist for this service. If set to
  15977. 0, @code{default-process-limit} is used instead.
  15978. Defaults to @samp{0}.
  15979. @end deftypevr
  15980. @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
  15981. Number of processes to always keep waiting for more connections.
  15982. Defaults to @samp{0}.
  15983. @end deftypevr
  15984. @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
  15985. If you set @samp{service-count 0}, you probably need to grow
  15986. this.
  15987. Defaults to @samp{256000000}.
  15988. @end deftypevr
  15989. @end deftypevr
  15990. @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
  15991. Dict configuration, as created by the @code{dict-configuration}
  15992. constructor.
  15993. Available @code{dict-configuration} fields are:
  15994. @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
  15995. A list of key-value pairs that this dict should hold.
  15996. Defaults to @samp{()}.
  15997. @end deftypevr
  15998. @end deftypevr
  15999. @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
  16000. A list of passdb configurations, each one created by the
  16001. @code{passdb-configuration} constructor.
  16002. Available @code{passdb-configuration} fields are:
  16003. @deftypevr {@code{passdb-configuration} parameter} string driver
  16004. The driver that the passdb should use. Valid values include
  16005. @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
  16006. @samp{static}.
  16007. Defaults to @samp{"pam"}.
  16008. @end deftypevr
  16009. @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
  16010. Space separated list of arguments to the passdb driver.
  16011. Defaults to @samp{""}.
  16012. @end deftypevr
  16013. @end deftypevr
  16014. @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
  16015. List of userdb configurations, each one created by the
  16016. @code{userdb-configuration} constructor.
  16017. Available @code{userdb-configuration} fields are:
  16018. @deftypevr {@code{userdb-configuration} parameter} string driver
  16019. The driver that the userdb should use. Valid values include
  16020. @samp{passwd} and @samp{static}.
  16021. Defaults to @samp{"passwd"}.
  16022. @end deftypevr
  16023. @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
  16024. Space separated list of arguments to the userdb driver.
  16025. Defaults to @samp{""}.
  16026. @end deftypevr
  16027. @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
  16028. Override fields from passwd.
  16029. Defaults to @samp{()}.
  16030. @end deftypevr
  16031. @end deftypevr
  16032. @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
  16033. Plug-in configuration, created by the @code{plugin-configuration}
  16034. constructor.
  16035. @end deftypevr
  16036. @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
  16037. List of namespaces. Each item in the list is created by the
  16038. @code{namespace-configuration} constructor.
  16039. Available @code{namespace-configuration} fields are:
  16040. @deftypevr {@code{namespace-configuration} parameter} string name
  16041. Name for this namespace.
  16042. @end deftypevr
  16043. @deftypevr {@code{namespace-configuration} parameter} string type
  16044. Namespace type: @samp{private}, @samp{shared} or @samp{public}.
  16045. Defaults to @samp{"private"}.
  16046. @end deftypevr
  16047. @deftypevr {@code{namespace-configuration} parameter} string separator
  16048. Hierarchy separator to use. You should use the same separator for
  16049. all namespaces or some clients get confused. @samp{/} is usually a good
  16050. one. The default however depends on the underlying mail storage
  16051. format.
  16052. Defaults to @samp{""}.
  16053. @end deftypevr
  16054. @deftypevr {@code{namespace-configuration} parameter} string prefix
  16055. Prefix required to access this namespace. This needs to be
  16056. different for all namespaces. For example @samp{Public/}.
  16057. Defaults to @samp{""}.
  16058. @end deftypevr
  16059. @deftypevr {@code{namespace-configuration} parameter} string location
  16060. Physical location of the mailbox. This is in the same format as
  16061. mail_location, which is also the default for it.
  16062. Defaults to @samp{""}.
  16063. @end deftypevr
  16064. @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
  16065. There can be only one INBOX, and this setting defines which
  16066. namespace has it.
  16067. Defaults to @samp{#f}.
  16068. @end deftypevr
  16069. @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
  16070. If namespace is hidden, it's not advertised to clients via NAMESPACE
  16071. extension. You'll most likely also want to set @samp{list? #f}. This is mostly
  16072. useful when converting from another server with different namespaces
  16073. which you want to deprecate but still keep working. For example you can
  16074. create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
  16075. and @samp{mail/}.
  16076. Defaults to @samp{#f}.
  16077. @end deftypevr
  16078. @deftypevr {@code{namespace-configuration} parameter} boolean list?
  16079. Show the mailboxes under this namespace with the LIST command. This
  16080. makes the namespace visible for clients that do not support the NAMESPACE
  16081. extension. The special @code{children} value lists child mailboxes, but
  16082. hides the namespace prefix.
  16083. Defaults to @samp{#t}.
  16084. @end deftypevr
  16085. @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
  16086. Namespace handles its own subscriptions. If set to @code{#f}, the
  16087. parent namespace handles them. The empty prefix should always have this
  16088. as @code{#t}).
  16089. Defaults to @samp{#t}.
  16090. @end deftypevr
  16091. @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
  16092. List of predefined mailboxes in this namespace.
  16093. Defaults to @samp{()}.
  16094. Available @code{mailbox-configuration} fields are:
  16095. @deftypevr {@code{mailbox-configuration} parameter} string name
  16096. Name for this mailbox.
  16097. @end deftypevr
  16098. @deftypevr {@code{mailbox-configuration} parameter} string auto
  16099. @samp{create} will automatically create this mailbox.
  16100. @samp{subscribe} will both create and subscribe to the mailbox.
  16101. Defaults to @samp{"no"}.
  16102. @end deftypevr
  16103. @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
  16104. List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
  16105. Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
  16106. @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
  16107. Defaults to @samp{()}.
  16108. @end deftypevr
  16109. @end deftypevr
  16110. @end deftypevr
  16111. @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
  16112. Base directory where to store runtime data.
  16113. Defaults to @samp{"/var/run/dovecot/"}.
  16114. @end deftypevr
  16115. @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
  16116. Greeting message for clients.
  16117. Defaults to @samp{"Dovecot ready."}.
  16118. @end deftypevr
  16119. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
  16120. List of trusted network ranges. Connections from these IPs are
  16121. allowed to override their IP addresses and ports (for logging and for
  16122. authentication checks). @samp{disable-plaintext-auth} is also ignored
  16123. for these networks. Typically you would specify your IMAP proxy servers
  16124. here.
  16125. Defaults to @samp{()}.
  16126. @end deftypevr
  16127. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
  16128. List of login access check sockets (e.g.@: tcpwrap).
  16129. Defaults to @samp{()}.
  16130. @end deftypevr
  16131. @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
  16132. Show more verbose process titles (in ps). Currently shows user name
  16133. and IP address. Useful for seeing who is actually using the IMAP
  16134. processes (e.g.@: shared mailboxes or if the same uid is used for multiple
  16135. accounts).
  16136. Defaults to @samp{#f}.
  16137. @end deftypevr
  16138. @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
  16139. Should all processes be killed when Dovecot master process shuts down.
  16140. Setting this to @code{#f} means that Dovecot can be upgraded without
  16141. forcing existing client connections to close (although that could also
  16142. be a problem if the upgrade is e.g.@: due to a security fix).
  16143. Defaults to @samp{#t}.
  16144. @end deftypevr
  16145. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
  16146. If non-zero, run mail commands via this many connections to doveadm
  16147. server, instead of running them directly in the same process.
  16148. Defaults to @samp{0}.
  16149. @end deftypevr
  16150. @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
  16151. UNIX socket or host:port used for connecting to doveadm server.
  16152. Defaults to @samp{"doveadm-server"}.
  16153. @end deftypevr
  16154. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
  16155. List of environment variables that are preserved on Dovecot startup
  16156. and passed down to all of its child processes. You can also give
  16157. key=value pairs to always set specific settings.
  16158. @end deftypevr
  16159. @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
  16160. Disable LOGIN command and all other plaintext authentications unless
  16161. SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
  16162. matches the local IP (i.e.@: you're connecting from the same computer),
  16163. the connection is considered secure and plaintext authentication is
  16164. allowed. See also ssl=required setting.
  16165. Defaults to @samp{#t}.
  16166. @end deftypevr
  16167. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
  16168. Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
  16169. Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
  16170. for caching to be used.
  16171. Defaults to @samp{0}.
  16172. @end deftypevr
  16173. @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
  16174. Time to live for cached data. After TTL expires the cached record
  16175. is no longer used, *except* if the main database lookup returns internal
  16176. failure. We also try to handle password changes automatically: If
  16177. user's previous authentication was successful, but this one wasn't, the
  16178. cache isn't used. For now this works only with plaintext
  16179. authentication.
  16180. Defaults to @samp{"1 hour"}.
  16181. @end deftypevr
  16182. @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
  16183. TTL for negative hits (user not found, password mismatch).
  16184. 0 disables caching them completely.
  16185. Defaults to @samp{"1 hour"}.
  16186. @end deftypevr
  16187. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
  16188. List of realms for SASL authentication mechanisms that need them.
  16189. You can leave it empty if you don't want to support multiple realms.
  16190. Many clients simply use the first one listed here, so keep the default
  16191. realm first.
  16192. Defaults to @samp{()}.
  16193. @end deftypevr
  16194. @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
  16195. Default realm/domain to use if none was specified. This is used for
  16196. both SASL realms and appending @@domain to username in plaintext
  16197. logins.
  16198. Defaults to @samp{""}.
  16199. @end deftypevr
  16200. @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
  16201. List of allowed characters in username. If the user-given username
  16202. contains a character not listed in here, the login automatically fails.
  16203. This is just an extra check to make sure user can't exploit any
  16204. potential quote escaping vulnerabilities with SQL/LDAP databases. If
  16205. you want to allow all characters, set this value to empty.
  16206. Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
  16207. @end deftypevr
  16208. @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
  16209. Username character translations before it's looked up from
  16210. databases. The value contains series of from -> to characters. For
  16211. example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
  16212. translated to @samp{@@}.
  16213. Defaults to @samp{""}.
  16214. @end deftypevr
  16215. @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
  16216. Username formatting before it's looked up from databases. You can
  16217. use the standard variables here, e.g.@: %Lu would lowercase the username,
  16218. %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
  16219. change the @samp{@@} into @samp{-AT-}. This translation is done after
  16220. @samp{auth-username-translation} changes.
  16221. Defaults to @samp{"%Lu"}.
  16222. @end deftypevr
  16223. @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
  16224. If you want to allow master users to log in by specifying the master
  16225. username within the normal username string (i.e.@: not using SASL
  16226. mechanism's support for it), you can specify the separator character
  16227. here. The format is then <username><separator><master username>.
  16228. UW-IMAP uses @samp{*} as the separator, so that could be a good
  16229. choice.
  16230. Defaults to @samp{""}.
  16231. @end deftypevr
  16232. @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
  16233. Username to use for users logging in with ANONYMOUS SASL
  16234. mechanism.
  16235. Defaults to @samp{"anonymous"}.
  16236. @end deftypevr
  16237. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
  16238. Maximum number of dovecot-auth worker processes. They're used to
  16239. execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
  16240. They're automatically created and destroyed as needed.
  16241. Defaults to @samp{30}.
  16242. @end deftypevr
  16243. @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
  16244. Host name to use in GSSAPI principal names. The default is to use
  16245. the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
  16246. allow all keytab entries.
  16247. Defaults to @samp{""}.
  16248. @end deftypevr
  16249. @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
  16250. Kerberos keytab to use for the GSSAPI mechanism. Will use the
  16251. system default (usually @file{/etc/krb5.keytab}) if not specified. You may
  16252. need to change the auth service to run as root to be able to read this
  16253. file.
  16254. Defaults to @samp{""}.
  16255. @end deftypevr
  16256. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
  16257. Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
  16258. and @samp{ntlm-auth} helper.
  16259. <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
  16260. Defaults to @samp{#f}.
  16261. @end deftypevr
  16262. @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
  16263. Path for Samba's @samp{ntlm-auth} helper binary.
  16264. Defaults to @samp{"/usr/bin/ntlm_auth"}.
  16265. @end deftypevr
  16266. @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
  16267. Time to delay before replying to failed authentications.
  16268. Defaults to @samp{"2 secs"}.
  16269. @end deftypevr
  16270. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
  16271. Require a valid SSL client certificate or the authentication
  16272. fails.
  16273. Defaults to @samp{#f}.
  16274. @end deftypevr
  16275. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
  16276. Take the username from client's SSL certificate, using
  16277. @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
  16278. CommonName.
  16279. Defaults to @samp{#f}.
  16280. @end deftypevr
  16281. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
  16282. List of wanted authentication mechanisms. Supported mechanisms are:
  16283. @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
  16284. @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
  16285. @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
  16286. @samp{disable-plaintext-auth} setting.
  16287. @end deftypevr
  16288. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
  16289. List of IPs or hostnames to all director servers, including ourself.
  16290. Ports can be specified as ip:port. The default port is the same as what
  16291. director service's @samp{inet-listener} is using.
  16292. Defaults to @samp{()}.
  16293. @end deftypevr
  16294. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
  16295. List of IPs or hostnames to all backend mail servers. Ranges are
  16296. allowed too, like 10.0.0.10-10.0.0.30.
  16297. Defaults to @samp{()}.
  16298. @end deftypevr
  16299. @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
  16300. How long to redirect users to a specific server after it no longer
  16301. has any connections.
  16302. Defaults to @samp{"15 min"}.
  16303. @end deftypevr
  16304. @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
  16305. How the username is translated before being hashed. Useful values
  16306. include %Ln if user can log in with or without @@domain, %Ld if mailboxes
  16307. are shared within domain.
  16308. Defaults to @samp{"%Lu"}.
  16309. @end deftypevr
  16310. @deftypevr {@code{dovecot-configuration} parameter} string log-path
  16311. Log file to use for error messages. @samp{syslog} logs to syslog,
  16312. @samp{/dev/stderr} logs to stderr.
  16313. Defaults to @samp{"syslog"}.
  16314. @end deftypevr
  16315. @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
  16316. Log file to use for informational messages. Defaults to
  16317. @samp{log-path}.
  16318. Defaults to @samp{""}.
  16319. @end deftypevr
  16320. @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
  16321. Log file to use for debug messages. Defaults to
  16322. @samp{info-log-path}.
  16323. Defaults to @samp{""}.
  16324. @end deftypevr
  16325. @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
  16326. Syslog facility to use if you're logging to syslog. Usually if you
  16327. don't want to use @samp{mail}, you'll use local0..local7. Also other
  16328. standard facilities are supported.
  16329. Defaults to @samp{"mail"}.
  16330. @end deftypevr
  16331. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
  16332. Log unsuccessful authentication attempts and the reasons why they
  16333. failed.
  16334. Defaults to @samp{#f}.
  16335. @end deftypevr
  16336. @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
  16337. In case of password mismatches, log the attempted password. Valid
  16338. values are no, plain and sha1. sha1 can be useful for detecting brute
  16339. force password attempts vs. user simply trying the same password over
  16340. and over again. You can also truncate the value to n chars by appending
  16341. ":n" (e.g.@: sha1:6).
  16342. Defaults to @samp{"no"}.
  16343. @end deftypevr
  16344. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
  16345. Even more verbose logging for debugging purposes. Shows for example
  16346. SQL queries.
  16347. Defaults to @samp{#f}.
  16348. @end deftypevr
  16349. @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
  16350. In case of password mismatches, log the passwords and used scheme so
  16351. the problem can be debugged. Enabling this also enables
  16352. @samp{auth-debug}.
  16353. Defaults to @samp{#f}.
  16354. @end deftypevr
  16355. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
  16356. Enable mail process debugging. This can help you figure out why
  16357. Dovecot isn't finding your mails.
  16358. Defaults to @samp{#f}.
  16359. @end deftypevr
  16360. @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
  16361. Show protocol level SSL errors.
  16362. Defaults to @samp{#f}.
  16363. @end deftypevr
  16364. @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
  16365. Prefix for each line written to log file. % codes are in
  16366. strftime(3) format.
  16367. Defaults to @samp{"\"%b %d %H:%M:%S \""}.
  16368. @end deftypevr
  16369. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
  16370. List of elements we want to log. The elements which have a
  16371. non-empty variable value are joined together to form a comma-separated
  16372. string.
  16373. @end deftypevr
  16374. @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
  16375. Login log format. %s contains @samp{login-log-format-elements}
  16376. string, %$ contains the data we want to log.
  16377. Defaults to @samp{"%$: %s"}.
  16378. @end deftypevr
  16379. @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
  16380. Log prefix for mail processes. See doc/wiki/Variables.txt for list
  16381. of possible variables you can use.
  16382. Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
  16383. @end deftypevr
  16384. @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
  16385. Format to use for logging mail deliveries. You can use variables:
  16386. @table @code
  16387. @item %$
  16388. Delivery status message (e.g.@: @samp{saved to INBOX})
  16389. @item %m
  16390. Message-ID
  16391. @item %s
  16392. Subject
  16393. @item %f
  16394. From address
  16395. @item %p
  16396. Physical size
  16397. @item %w
  16398. Virtual size.
  16399. @end table
  16400. Defaults to @samp{"msgid=%m: %$"}.
  16401. @end deftypevr
  16402. @deftypevr {@code{dovecot-configuration} parameter} string mail-location
  16403. Location for users' mailboxes. The default is empty, which means
  16404. that Dovecot tries to find the mailboxes automatically. This won't work
  16405. if the user doesn't yet have any mail, so you should explicitly tell
  16406. Dovecot the full location.
  16407. If you're using mbox, giving a path to the INBOX
  16408. file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
  16409. where the other mailboxes are kept. This is called the @emph{root mail
  16410. directory}, and it must be the first path given in the
  16411. @samp{mail-location} setting.
  16412. There are a few special variables you can use, e.g.:
  16413. @table @samp
  16414. @item %u
  16415. username
  16416. @item %n
  16417. user part in user@@domain, same as %u if there's no domain
  16418. @item %d
  16419. domain part in user@@domain, empty if there's no domain
  16420. @item %h
  16421. home director
  16422. @end table
  16423. See doc/wiki/Variables.txt for full list. Some examples:
  16424. @table @samp
  16425. @item maildir:~/Maildir
  16426. @item mbox:~/mail:INBOX=/var/mail/%u
  16427. @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
  16428. @end table
  16429. Defaults to @samp{""}.
  16430. @end deftypevr
  16431. @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
  16432. System user and group used to access mails. If you use multiple,
  16433. userdb can override these by returning uid or gid fields. You can use
  16434. either numbers or names. <doc/wiki/UserIds.txt>.
  16435. Defaults to @samp{""}.
  16436. @end deftypevr
  16437. @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
  16438. Defaults to @samp{""}.
  16439. @end deftypevr
  16440. @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
  16441. Group to enable temporarily for privileged operations. Currently
  16442. this is used only with INBOX when either its initial creation or
  16443. dotlocking fails. Typically this is set to @samp{"mail"} to give access to
  16444. @file{/var/mail}.
  16445. Defaults to @samp{""}.
  16446. @end deftypevr
  16447. @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
  16448. Grant access to these supplementary groups for mail processes.
  16449. Typically these are used to set up access to shared mailboxes. Note
  16450. that it may be dangerous to set these if users can create symlinks
  16451. (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
  16452. could allow a user to delete others' mailboxes, or @code{ln -s
  16453. /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
  16454. @samp{""}.
  16455. @end deftypevr
  16456. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
  16457. Allow full file system access to clients. There's no access checks
  16458. other than what the operating system does for the active UID/GID@. It
  16459. works with both maildir and mboxes, allowing you to prefix mailboxes
  16460. names with e.g.@: @file{/path/} or @file{~user/}.
  16461. Defaults to @samp{#f}.
  16462. @end deftypevr
  16463. @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
  16464. Don't use @code{mmap()} at all. This is required if you store indexes to
  16465. shared file systems (NFS or clustered file system).
  16466. Defaults to @samp{#f}.
  16467. @end deftypevr
  16468. @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
  16469. Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
  16470. supports @samp{O_EXCL} since version 3, so this should be safe to use
  16471. nowadays by default.
  16472. Defaults to @samp{#t}.
  16473. @end deftypevr
  16474. @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
  16475. When to use fsync() or fdatasync() calls:
  16476. @table @code
  16477. @item optimized
  16478. Whenever necessary to avoid losing important data
  16479. @item always
  16480. Useful with e.g.@: NFS when @code{write()}s are delayed
  16481. @item never
  16482. Never use it (best performance, but crashes can lose data).
  16483. @end table
  16484. Defaults to @samp{"optimized"}.
  16485. @end deftypevr
  16486. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
  16487. Mail storage exists in NFS@. Set this to yes to make Dovecot flush
  16488. NFS caches whenever needed. If you're using only a single mail server
  16489. this isn't needed.
  16490. Defaults to @samp{#f}.
  16491. @end deftypevr
  16492. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
  16493. Mail index files also exist in NFS@. Setting this to yes requires
  16494. @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
  16495. Defaults to @samp{#f}.
  16496. @end deftypevr
  16497. @deftypevr {@code{dovecot-configuration} parameter} string lock-method
  16498. Locking method for index files. Alternatives are fcntl, flock and
  16499. dotlock. Dotlocking uses some tricks which may create more disk I/O
  16500. than other locking methods. NFS users: flock doesn't work, remember to
  16501. change @samp{mmap-disable}.
  16502. Defaults to @samp{"fcntl"}.
  16503. @end deftypevr
  16504. @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
  16505. Directory in which LDA/LMTP temporarily stores incoming mails >128
  16506. kB.
  16507. Defaults to @samp{"/tmp"}.
  16508. @end deftypevr
  16509. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
  16510. Valid UID range for users. This is mostly to make sure that users can't
  16511. log in as daemons or other system users. Note that denying root logins is
  16512. hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
  16513. is set to 0.
  16514. Defaults to @samp{500}.
  16515. @end deftypevr
  16516. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
  16517. Defaults to @samp{0}.
  16518. @end deftypevr
  16519. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
  16520. Valid GID range for users. Users having non-valid GID as primary group ID
  16521. aren't allowed to log in. If user belongs to supplementary groups with
  16522. non-valid GIDs, those groups are not set.
  16523. Defaults to @samp{1}.
  16524. @end deftypevr
  16525. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
  16526. Defaults to @samp{0}.
  16527. @end deftypevr
  16528. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
  16529. Maximum allowed length for mail keyword name. It's only forced when
  16530. trying to create new keywords.
  16531. Defaults to @samp{50}.
  16532. @end deftypevr
  16533. @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
  16534. List of directories under which chrooting is allowed for mail
  16535. processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
  16536. too). This setting doesn't affect @samp{login-chroot}
  16537. @samp{mail-chroot} or auth chroot settings. If this setting is empty,
  16538. @samp{/./} in home dirs are ignored. WARNING: Never add directories here
  16539. which local users can modify, that may lead to root exploit. Usually
  16540. this should be done only if you don't allow shell access for users.
  16541. <doc/wiki/Chrooting.txt>.
  16542. Defaults to @samp{()}.
  16543. @end deftypevr
  16544. @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
  16545. Default chroot directory for mail processes. This can be overridden
  16546. for specific users in user database by giving @samp{/./} in user's home
  16547. directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
  16548. there is no real need to do chrooting, Dovecot doesn't allow users to
  16549. access files outside their mail directory anyway. If your home
  16550. directories are prefixed with the chroot directory, append @samp{/.} to
  16551. @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
  16552. Defaults to @samp{""}.
  16553. @end deftypevr
  16554. @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
  16555. UNIX socket path to master authentication server to find users.
  16556. This is used by imap (for shared users) and lda.
  16557. Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
  16558. @end deftypevr
  16559. @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
  16560. Directory where to look up mail plugins.
  16561. Defaults to @samp{"/usr/lib/dovecot"}.
  16562. @end deftypevr
  16563. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
  16564. List of plugins to load for all services. Plugins specific to IMAP,
  16565. LDA, etc.@: are added to this list in their own .conf files.
  16566. Defaults to @samp{()}.
  16567. @end deftypevr
  16568. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
  16569. The minimum number of mails in a mailbox before updates are done to
  16570. cache file. This allows optimizing Dovecot's behavior to do less disk
  16571. writes at the cost of more disk reads.
  16572. Defaults to @samp{0}.
  16573. @end deftypevr
  16574. @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
  16575. When IDLE command is running, mailbox is checked once in a while to
  16576. see if there are any new mails or other changes. This setting defines
  16577. the minimum time to wait between those checks. Dovecot can also use
  16578. dnotify, inotify and kqueue to find out immediately when changes
  16579. occur.
  16580. Defaults to @samp{"30 secs"}.
  16581. @end deftypevr
  16582. @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
  16583. Save mails with CR+LF instead of plain LF@. This makes sending those
  16584. mails take less CPU, especially with sendfile() syscall with Linux and
  16585. FreeBSD@. But it also creates a bit more disk I/O which may just make it
  16586. slower. Also note that if other software reads the mboxes/maildirs,
  16587. they may handle the extra CRs wrong and cause problems.
  16588. Defaults to @samp{#f}.
  16589. @end deftypevr
  16590. @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
  16591. By default LIST command returns all entries in maildir beginning
  16592. with a dot. Enabling this option makes Dovecot return only entries
  16593. which are directories. This is done by stat()ing each entry, so it
  16594. causes more disk I/O.
  16595. (For systems setting struct @samp{dirent->d_type} this check is free
  16596. and it's done always regardless of this setting).
  16597. Defaults to @samp{#f}.
  16598. @end deftypevr
  16599. @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
  16600. When copying a message, do it with hard links whenever possible.
  16601. This makes the performance much better, and it's unlikely to have any
  16602. side effects.
  16603. Defaults to @samp{#t}.
  16604. @end deftypevr
  16605. @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
  16606. Assume Dovecot is the only MUA accessing Maildir: Scan cur/
  16607. directory only when its mtime changes unexpectedly or when we can't find
  16608. the mail otherwise.
  16609. Defaults to @samp{#f}.
  16610. @end deftypevr
  16611. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
  16612. Which locking methods to use for locking mbox. There are four
  16613. available:
  16614. @table @code
  16615. @item dotlock
  16616. Create <mailbox>.lock file. This is the oldest and most NFS-safe
  16617. solution. If you want to use /var/mail/ like directory, the users will
  16618. need write access to that directory.
  16619. @item dotlock-try
  16620. Same as dotlock, but if it fails because of permissions or because there
  16621. isn't enough disk space, just skip it.
  16622. @item fcntl
  16623. Use this if possible. Works with NFS too if lockd is used.
  16624. @item flock
  16625. May not exist in all systems. Doesn't work with NFS.
  16626. @item lockf
  16627. May not exist in all systems. Doesn't work with NFS.
  16628. @end table
  16629. You can use multiple locking methods; if you do the order they're declared
  16630. in is important to avoid deadlocks if other MTAs/MUAs are using multiple
  16631. locking methods as well. Some operating systems don't allow using some of
  16632. them simultaneously.
  16633. @end deftypevr
  16634. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
  16635. @end deftypevr
  16636. @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
  16637. Maximum time to wait for lock (all of them) before aborting.
  16638. Defaults to @samp{"5 mins"}.
  16639. @end deftypevr
  16640. @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
  16641. If dotlock exists but the mailbox isn't modified in any way,
  16642. override the lock file after this much time.
  16643. Defaults to @samp{"2 mins"}.
  16644. @end deftypevr
  16645. @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
  16646. When mbox changes unexpectedly we have to fully read it to find out
  16647. what changed. If the mbox is large this can take a long time. Since
  16648. the change is usually just a newly appended mail, it'd be faster to
  16649. simply read the new mails. If this setting is enabled, Dovecot does
  16650. this but still safely fallbacks to re-reading the whole mbox file
  16651. whenever something in mbox isn't how it's expected to be. The only real
  16652. downside to this setting is that if some other MUA changes message
  16653. flags, Dovecot doesn't notice it immediately. Note that a full sync is
  16654. done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
  16655. Defaults to @samp{#t}.
  16656. @end deftypevr
  16657. @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
  16658. Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
  16659. EXAMINE, EXPUNGE or CHECK commands. If this is set,
  16660. @samp{mbox-dirty-syncs} is ignored.
  16661. Defaults to @samp{#f}.
  16662. @end deftypevr
  16663. @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
  16664. Delay writing mbox headers until doing a full write sync (EXPUNGE
  16665. and CHECK commands and when closing the mailbox). This is especially
  16666. useful for POP3 where clients often delete all mails. The downside is
  16667. that our changes aren't immediately visible to other MUAs.
  16668. Defaults to @samp{#t}.
  16669. @end deftypevr
  16670. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
  16671. If mbox size is smaller than this (e.g.@: 100k), don't write index
  16672. files. If an index file already exists it's still read, just not
  16673. updated.
  16674. Defaults to @samp{0}.
  16675. @end deftypevr
  16676. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
  16677. Maximum dbox file size until it's rotated.
  16678. Defaults to @samp{10000000}.
  16679. @end deftypevr
  16680. @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
  16681. Maximum dbox file age until it's rotated. Typically in days. Day
  16682. begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
  16683. disabled.
  16684. Defaults to @samp{"1d"}.
  16685. @end deftypevr
  16686. @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
  16687. When creating new mdbox files, immediately preallocate their size to
  16688. @samp{mdbox-rotate-size}. This setting currently works only in Linux
  16689. with some file systems (ext4, xfs).
  16690. Defaults to @samp{#f}.
  16691. @end deftypevr
  16692. @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
  16693. sdbox and mdbox support saving mail attachments to external files,
  16694. which also allows single instance storage for them. Other backends
  16695. don't support this for now.
  16696. WARNING: This feature hasn't been tested much yet. Use at your own risk.
  16697. Directory root where to store mail attachments. Disabled, if empty.
  16698. Defaults to @samp{""}.
  16699. @end deftypevr
  16700. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
  16701. Attachments smaller than this aren't saved externally. It's also
  16702. possible to write a plugin to disable saving specific attachments
  16703. externally.
  16704. Defaults to @samp{128000}.
  16705. @end deftypevr
  16706. @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
  16707. File system backend to use for saving attachments:
  16708. @table @code
  16709. @item posix
  16710. No SiS done by Dovecot (but this might help FS's own deduplication)
  16711. @item sis posix
  16712. SiS with immediate byte-by-byte comparison during saving
  16713. @item sis-queue posix
  16714. SiS with delayed comparison and deduplication.
  16715. @end table
  16716. Defaults to @samp{"sis posix"}.
  16717. @end deftypevr
  16718. @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
  16719. Hash format to use in attachment filenames. You can add any text and
  16720. variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
  16721. @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
  16722. truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
  16723. Defaults to @samp{"%@{sha1@}"}.
  16724. @end deftypevr
  16725. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
  16726. Defaults to @samp{100}.
  16727. @end deftypevr
  16728. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
  16729. Defaults to @samp{1000}.
  16730. @end deftypevr
  16731. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
  16732. Default VSZ (virtual memory size) limit for service processes.
  16733. This is mainly intended to catch and kill processes that leak memory
  16734. before they eat up everything.
  16735. Defaults to @samp{256000000}.
  16736. @end deftypevr
  16737. @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
  16738. Login user is internally used by login processes. This is the most
  16739. untrusted user in Dovecot system. It shouldn't have access to anything
  16740. at all.
  16741. Defaults to @samp{"dovenull"}.
  16742. @end deftypevr
  16743. @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
  16744. Internal user is used by unprivileged processes. It should be
  16745. separate from login user, so that login processes can't disturb other
  16746. processes.
  16747. Defaults to @samp{"dovecot"}.
  16748. @end deftypevr
  16749. @deftypevr {@code{dovecot-configuration} parameter} string ssl?
  16750. SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
  16751. Defaults to @samp{"required"}.
  16752. @end deftypevr
  16753. @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
  16754. PEM encoded X.509 SSL/TLS certificate (public key).
  16755. Defaults to @samp{"</etc/dovecot/default.pem"}.
  16756. @end deftypevr
  16757. @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
  16758. PEM encoded SSL/TLS private key. The key is opened before
  16759. dropping root privileges, so keep the key file unreadable by anyone but
  16760. root.
  16761. Defaults to @samp{"</etc/dovecot/private/default.pem"}.
  16762. @end deftypevr
  16763. @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
  16764. If key file is password protected, give the password here.
  16765. Alternatively give it when starting dovecot with -p parameter. Since
  16766. this file is often world-readable, you may want to place this setting
  16767. instead to a different.
  16768. Defaults to @samp{""}.
  16769. @end deftypevr
  16770. @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
  16771. PEM encoded trusted certificate authority. Set this only if you
  16772. intend to use @samp{ssl-verify-client-cert? #t}. The file should
  16773. contain the CA certificate(s) followed by the matching
  16774. CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
  16775. Defaults to @samp{""}.
  16776. @end deftypevr
  16777. @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
  16778. Require that CRL check succeeds for client certificates.
  16779. Defaults to @samp{#t}.
  16780. @end deftypevr
  16781. @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
  16782. Request client to send a certificate. If you also want to require
  16783. it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
  16784. Defaults to @samp{#f}.
  16785. @end deftypevr
  16786. @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
  16787. Which field from certificate to use for username. commonName and
  16788. x500UniqueIdentifier are the usual choices. You'll also need to set
  16789. @samp{auth-ssl-username-from-cert? #t}.
  16790. Defaults to @samp{"commonName"}.
  16791. @end deftypevr
  16792. @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
  16793. Minimum SSL protocol version to accept.
  16794. Defaults to @samp{"TLSv1"}.
  16795. @end deftypevr
  16796. @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
  16797. SSL ciphers to use.
  16798. Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
  16799. @end deftypevr
  16800. @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
  16801. SSL crypto device to use, for valid values run "openssl engine".
  16802. Defaults to @samp{""}.
  16803. @end deftypevr
  16804. @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
  16805. Address to use when sending rejection mails.
  16806. %d expands to recipient domain.
  16807. Defaults to @samp{"postmaster@@%d"}.
  16808. @end deftypevr
  16809. @deftypevr {@code{dovecot-configuration} parameter} string hostname
  16810. Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
  16811. and in LMTP replies. Default is the system's real hostname@@domain.
  16812. Defaults to @samp{""}.
  16813. @end deftypevr
  16814. @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
  16815. If user is over quota, return with temporary failure instead of
  16816. bouncing the mail.
  16817. Defaults to @samp{#f}.
  16818. @end deftypevr
  16819. @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
  16820. Binary to use for sending mails.
  16821. Defaults to @samp{"/usr/sbin/sendmail"}.
  16822. @end deftypevr
  16823. @deftypevr {@code{dovecot-configuration} parameter} string submission-host
  16824. If non-empty, send mails via this SMTP host[:port] instead of
  16825. sendmail.
  16826. Defaults to @samp{""}.
  16827. @end deftypevr
  16828. @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
  16829. Subject: header to use for rejection mails. You can use the same
  16830. variables as for @samp{rejection-reason} below.
  16831. Defaults to @samp{"Rejected: %s"}.
  16832. @end deftypevr
  16833. @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
  16834. Human readable error message for rejection mails. You can use
  16835. variables:
  16836. @table @code
  16837. @item %n
  16838. CRLF
  16839. @item %r
  16840. reason
  16841. @item %s
  16842. original subject
  16843. @item %t
  16844. recipient
  16845. @end table
  16846. Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
  16847. @end deftypevr
  16848. @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
  16849. Delimiter character between local-part and detail in email
  16850. address.
  16851. Defaults to @samp{"+"}.
  16852. @end deftypevr
  16853. @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
  16854. Header where the original recipient address (SMTP's RCPT TO:
  16855. address) is taken from if not available elsewhere. With dovecot-lda -a
  16856. parameter overrides this. A commonly used header for this is
  16857. X-Original-To.
  16858. Defaults to @samp{""}.
  16859. @end deftypevr
  16860. @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
  16861. Should saving a mail to a nonexistent mailbox automatically create
  16862. it?.
  16863. Defaults to @samp{#f}.
  16864. @end deftypevr
  16865. @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
  16866. Should automatically created mailboxes be also automatically
  16867. subscribed?.
  16868. Defaults to @samp{#f}.
  16869. @end deftypevr
  16870. @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
  16871. Maximum IMAP command line length. Some clients generate very long
  16872. command lines with huge mailboxes, so you may need to raise this if you
  16873. get "Too long argument" or "IMAP command line too large" errors
  16874. often.
  16875. Defaults to @samp{64000}.
  16876. @end deftypevr
  16877. @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
  16878. IMAP logout format string:
  16879. @table @code
  16880. @item %i
  16881. total number of bytes read from client
  16882. @item %o
  16883. total number of bytes sent to client.
  16884. @end table
  16885. See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
  16886. 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@}"}.
  16887. @end deftypevr
  16888. @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
  16889. Override the IMAP CAPABILITY response. If the value begins with '+',
  16890. add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
  16891. Defaults to @samp{""}.
  16892. @end deftypevr
  16893. @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
  16894. How long to wait between "OK Still here" notifications when client
  16895. is IDLEing.
  16896. Defaults to @samp{"2 mins"}.
  16897. @end deftypevr
  16898. @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
  16899. ID field names and values to send to clients. Using * as the value
  16900. makes Dovecot use the default value. The following fields have default
  16901. values currently: name, version, os, os-version, support-url,
  16902. support-email.
  16903. Defaults to @samp{""}.
  16904. @end deftypevr
  16905. @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
  16906. ID fields sent by client to log. * means everything.
  16907. Defaults to @samp{""}.
  16908. @end deftypevr
  16909. @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
  16910. Workarounds for various client bugs:
  16911. @table @code
  16912. @item delay-newmail
  16913. Send EXISTS/RECENT new mail notifications only when replying to NOOP and
  16914. CHECK commands. Some clients ignore them otherwise, for example OSX
  16915. Mail (<v2.1). Outlook Express breaks more badly though, without this it
  16916. may show user "Message no longer in server" errors. Note that OE6
  16917. still breaks even with this workaround if synchronization is set to
  16918. "Headers Only".
  16919. @item tb-extra-mailbox-sep
  16920. Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
  16921. adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
  16922. ignore the extra @samp{/} instead of treating it as invalid mailbox name.
  16923. @item tb-lsub-flags
  16924. Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
  16925. This makes Thunderbird realize they aren't selectable and show them
  16926. greyed out, instead of only later giving "not selectable" popup error.
  16927. @end table
  16928. Defaults to @samp{()}.
  16929. @end deftypevr
  16930. @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
  16931. Host allowed in URLAUTH URLs sent by client. "*" allows all.
  16932. Defaults to @samp{""}.
  16933. @end deftypevr
  16934. Whew! Lots of configuration options. The nice thing about it though is
  16935. that Guix has a complete interface to Dovecot's configuration
  16936. language. This allows not only a nice way to declare configurations,
  16937. but also offers reflective capabilities as well: users can write code to
  16938. inspect and transform configurations from within Scheme.
  16939. However, it could be that you just want to get a @code{dovecot.conf} up
  16940. and running. In that case, you can pass an
  16941. @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
  16942. @code{dovecot-service}. As its name indicates, an opaque configuration
  16943. does not have easy reflective capabilities.
  16944. Available @code{opaque-dovecot-configuration} fields are:
  16945. @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
  16946. The dovecot package.
  16947. @end deftypevr
  16948. @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
  16949. The contents of the @code{dovecot.conf}, as a string.
  16950. @end deftypevr
  16951. For example, if your @code{dovecot.conf} is just the empty string, you
  16952. could instantiate a dovecot service like this:
  16953. @lisp
  16954. (dovecot-service #:config
  16955. (opaque-dovecot-configuration
  16956. (string "")))
  16957. @end lisp
  16958. @subsubheading OpenSMTPD Service
  16959. @deffn {Scheme Variable} opensmtpd-service-type
  16960. This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
  16961. service, whose value should be an @code{opensmtpd-configuration} object
  16962. as in this example:
  16963. @lisp
  16964. (service opensmtpd-service-type
  16965. (opensmtpd-configuration
  16966. (config-file (local-file "./my-smtpd.conf"))))
  16967. @end lisp
  16968. @end deffn
  16969. @deftp {Data Type} opensmtpd-configuration
  16970. Data type representing the configuration of opensmtpd.
  16971. @table @asis
  16972. @item @code{package} (default: @var{opensmtpd})
  16973. Package object of the OpenSMTPD SMTP server.
  16974. @item @code{config-file} (default: @code{%default-opensmtpd-file})
  16975. File-like object of the OpenSMTPD configuration file to use. By default
  16976. it listens on the loopback network interface, and allows for mail from
  16977. users and daemons on the local machine, as well as permitting email to
  16978. remote servers. Run @command{man smtpd.conf} for more information.
  16979. @end table
  16980. @end deftp
  16981. @subsubheading Exim Service
  16982. @cindex mail transfer agent (MTA)
  16983. @cindex MTA (mail transfer agent)
  16984. @cindex SMTP
  16985. @deffn {Scheme Variable} exim-service-type
  16986. This is the type of the @uref{https://exim.org, Exim} mail transfer
  16987. agent (MTA), whose value should be an @code{exim-configuration} object
  16988. as in this example:
  16989. @lisp
  16990. (service exim-service-type
  16991. (exim-configuration
  16992. (config-file (local-file "./my-exim.conf"))))
  16993. @end lisp
  16994. @end deffn
  16995. In order to use an @code{exim-service-type} service you must also have a
  16996. @code{mail-aliases-service-type} service present in your
  16997. @code{operating-system} (even if it has no aliases).
  16998. @deftp {Data Type} exim-configuration
  16999. Data type representing the configuration of exim.
  17000. @table @asis
  17001. @item @code{package} (default: @var{exim})
  17002. Package object of the Exim server.
  17003. @item @code{config-file} (default: @code{#f})
  17004. File-like object of the Exim configuration file to use. If its value is
  17005. @code{#f} then use the default configuration file from the package
  17006. provided in @code{package}. The resulting configuration file is loaded
  17007. after setting the @code{exim_user} and @code{exim_group} configuration
  17008. variables.
  17009. @end table
  17010. @end deftp
  17011. @subsubheading Getmail service
  17012. @cindex IMAP
  17013. @cindex POP
  17014. @deffn {Scheme Variable} getmail-service-type
  17015. This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
  17016. mail retriever, whose value should be an @code{getmail-configuration}.
  17017. @end deffn
  17018. Available @code{getmail-configuration} fields are:
  17019. @deftypevr {@code{getmail-configuration} parameter} symbol name
  17020. A symbol to identify the getmail service.
  17021. Defaults to @samp{"unset"}.
  17022. @end deftypevr
  17023. @deftypevr {@code{getmail-configuration} parameter} package package
  17024. The getmail package to use.
  17025. @end deftypevr
  17026. @deftypevr {@code{getmail-configuration} parameter} string user
  17027. The user to run getmail as.
  17028. Defaults to @samp{"getmail"}.
  17029. @end deftypevr
  17030. @deftypevr {@code{getmail-configuration} parameter} string group
  17031. The group to run getmail as.
  17032. Defaults to @samp{"getmail"}.
  17033. @end deftypevr
  17034. @deftypevr {@code{getmail-configuration} parameter} string directory
  17035. The getmail directory to use.
  17036. Defaults to @samp{"/var/lib/getmail/default"}.
  17037. @end deftypevr
  17038. @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
  17039. The getmail configuration file to use.
  17040. Available @code{getmail-configuration-file} fields are:
  17041. @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
  17042. What mail account to retrieve mail from, and how to access that account.
  17043. Available @code{getmail-retriever-configuration} fields are:
  17044. @deftypevr {@code{getmail-retriever-configuration} parameter} string type
  17045. The type of mail retriever to use. Valid values include @samp{passwd}
  17046. and @samp{static}.
  17047. Defaults to @samp{"SimpleIMAPSSLRetriever"}.
  17048. @end deftypevr
  17049. @deftypevr {@code{getmail-retriever-configuration} parameter} string server
  17050. Username to login to the mail server with.
  17051. Defaults to @samp{unset}.
  17052. @end deftypevr
  17053. @deftypevr {@code{getmail-retriever-configuration} parameter} string username
  17054. Username to login to the mail server with.
  17055. Defaults to @samp{unset}.
  17056. @end deftypevr
  17057. @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
  17058. Port number to connect to.
  17059. Defaults to @samp{#f}.
  17060. @end deftypevr
  17061. @deftypevr {@code{getmail-retriever-configuration} parameter} string password
  17062. Override fields from passwd.
  17063. Defaults to @samp{""}.
  17064. @end deftypevr
  17065. @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
  17066. Override fields from passwd.
  17067. Defaults to @samp{()}.
  17068. @end deftypevr
  17069. @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
  17070. PEM-formatted key file to use for the TLS negotiation.
  17071. Defaults to @samp{""}.
  17072. @end deftypevr
  17073. @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
  17074. PEM-formatted certificate file to use for the TLS negotiation.
  17075. Defaults to @samp{""}.
  17076. @end deftypevr
  17077. @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
  17078. CA certificates to use.
  17079. Defaults to @samp{""}.
  17080. @end deftypevr
  17081. @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
  17082. Extra retriever parameters.
  17083. Defaults to @samp{()}.
  17084. @end deftypevr
  17085. @end deftypevr
  17086. @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
  17087. What to do with retrieved messages.
  17088. Available @code{getmail-destination-configuration} fields are:
  17089. @deftypevr {@code{getmail-destination-configuration} parameter} string type
  17090. The type of mail destination. Valid values include @samp{Maildir},
  17091. @samp{Mboxrd} and @samp{MDA_external}.
  17092. Defaults to @samp{unset}.
  17093. @end deftypevr
  17094. @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
  17095. The path option for the mail destination. The behaviour depends on the
  17096. chosen type.
  17097. Defaults to @samp{""}.
  17098. @end deftypevr
  17099. @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
  17100. Extra destination parameters
  17101. Defaults to @samp{()}.
  17102. @end deftypevr
  17103. @end deftypevr
  17104. @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
  17105. Configure getmail.
  17106. Available @code{getmail-options-configuration} fields are:
  17107. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
  17108. If set to @samp{0}, getmail will only print warnings and errors. A
  17109. value of @samp{1} means that messages will be printed about retrieving
  17110. and deleting messages. If set to @samp{2}, getmail will print messages
  17111. about each of it's actions.
  17112. Defaults to @samp{1}.
  17113. @end deftypevr
  17114. @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
  17115. If true, getmail will retrieve all available messages. Otherwise it
  17116. will only retrieve messages it hasn't seen previously.
  17117. Defaults to @samp{#t}.
  17118. @end deftypevr
  17119. @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
  17120. If set to true, messages will be deleted from the server after
  17121. retrieving and successfully delivering them. Otherwise, messages will
  17122. be left on the server.
  17123. Defaults to @samp{#f}.
  17124. @end deftypevr
  17125. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
  17126. Getmail will delete messages this number of days after seeing them, if
  17127. they have been delivered. This means messages will be left on the
  17128. server this number of days after delivering them. A value of @samp{0}
  17129. disabled this feature.
  17130. Defaults to @samp{0}.
  17131. @end deftypevr
  17132. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
  17133. Delete messages larger than this of bytes after retrieving them, even if
  17134. the delete and delete-after options are disabled. A value of @samp{0}
  17135. disables this feature.
  17136. Defaults to @samp{0}.
  17137. @end deftypevr
  17138. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
  17139. Retrieve messages totalling up to this number of bytes before closing
  17140. the session with the server. A value of @samp{0} disables this feature.
  17141. Defaults to @samp{0}.
  17142. @end deftypevr
  17143. @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
  17144. Don't retrieve messages larger than this number of bytes. A value of
  17145. @samp{0} disables this feature.
  17146. Defaults to @samp{0}.
  17147. @end deftypevr
  17148. @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
  17149. If true, getmail will add a Delivered-To header to messages.
  17150. Defaults to @samp{#t}.
  17151. @end deftypevr
  17152. @deftypevr {@code{getmail-options-configuration} parameter} boolean received
  17153. If set, getmail adds a Received header to the messages.
  17154. Defaults to @samp{#t}.
  17155. @end deftypevr
  17156. @deftypevr {@code{getmail-options-configuration} parameter} string message-log
  17157. Getmail will record a log of its actions to the named file. A value of
  17158. @samp{""} disables this feature.
  17159. Defaults to @samp{""}.
  17160. @end deftypevr
  17161. @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
  17162. If true, getmail will record a log of its actions using the system
  17163. logger.
  17164. Defaults to @samp{#f}.
  17165. @end deftypevr
  17166. @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
  17167. If true, getmail will log information about messages not retrieved and
  17168. the reason for not retrieving them, as well as starting and ending
  17169. information lines.
  17170. Defaults to @samp{#f}.
  17171. @end deftypevr
  17172. @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
  17173. Extra options to include.
  17174. Defaults to @samp{()}.
  17175. @end deftypevr
  17176. @end deftypevr
  17177. @end deftypevr
  17178. @deftypevr {@code{getmail-configuration} parameter} list idle
  17179. A list of mailboxes that getmail should wait on the server for new mail
  17180. notifications. This depends on the server supporting the IDLE
  17181. extension.
  17182. Defaults to @samp{()}.
  17183. @end deftypevr
  17184. @deftypevr {@code{getmail-configuration} parameter} list environment-variables
  17185. Environment variables to set for getmail.
  17186. Defaults to @samp{()}.
  17187. @end deftypevr
  17188. @subsubheading Mail Aliases Service
  17189. @cindex email aliases
  17190. @cindex aliases, for email addresses
  17191. @deffn {Scheme Variable} mail-aliases-service-type
  17192. This is the type of the service which provides @code{/etc/aliases},
  17193. specifying how to deliver mail to users on this system.
  17194. @lisp
  17195. (service mail-aliases-service-type
  17196. '(("postmaster" "bob")
  17197. ("bob" "bob@@example.com" "bob@@example2.com")))
  17198. @end lisp
  17199. @end deffn
  17200. The configuration for a @code{mail-aliases-service-type} service is an
  17201. association list denoting how to deliver mail that comes to this
  17202. system. Each entry is of the form @code{(alias addresses ...)}, with
  17203. @code{alias} specifying the local alias and @code{addresses} specifying
  17204. where to deliver this user's mail.
  17205. The aliases aren't required to exist as users on the local system. In
  17206. the above example, there doesn't need to be a @code{postmaster} entry in
  17207. the @code{operating-system}'s @code{user-accounts} in order to deliver
  17208. the @code{postmaster} mail to @code{bob} (which subsequently would
  17209. deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
  17210. @subsubheading GNU Mailutils IMAP4 Daemon
  17211. @cindex GNU Mailutils IMAP4 Daemon
  17212. @deffn {Scheme Variable} imap4d-service-type
  17213. This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
  17214. mailutils, GNU Mailutils Manual}), whose value should be an
  17215. @code{imap4d-configuration} object as in this example:
  17216. @lisp
  17217. (service imap4d-service-type
  17218. (imap4d-configuration
  17219. (config-file (local-file "imap4d.conf"))))
  17220. @end lisp
  17221. @end deffn
  17222. @deftp {Data Type} imap4d-configuration
  17223. Data type representing the configuration of @command{imap4d}.
  17224. @table @asis
  17225. @item @code{package} (default: @code{mailutils})
  17226. The package that provides @command{imap4d}.
  17227. @item @code{config-file} (default: @code{%default-imap4d-config-file})
  17228. File-like object of the configuration file to use, by default it will listen
  17229. on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
  17230. Mailutils Manual}, for details.
  17231. @end table
  17232. @end deftp
  17233. @subsubheading Radicale Service
  17234. @cindex CalDAV
  17235. @cindex CardDAV
  17236. @deffn {Scheme Variable} radicale-service-type
  17237. This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
  17238. server whose value should be a @code{radicale-configuration}.
  17239. @end deffn
  17240. @deftp {Data Type} radicale-configuration
  17241. Data type representing the configuration of @command{radicale}.
  17242. @table @asis
  17243. @item @code{package} (default: @code{radicale})
  17244. The package that provides @command{radicale}.
  17245. @item @code{config-file} (default: @code{%default-radicale-config-file})
  17246. File-like object of the configuration file to use, by default it will listen
  17247. on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
  17248. @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
  17249. @end table
  17250. @end deftp
  17251. @node Messaging Services
  17252. @subsection Messaging Services
  17253. @cindex messaging
  17254. @cindex jabber
  17255. @cindex XMPP
  17256. The @code{(gnu services messaging)} module provides Guix service
  17257. definitions for messaging services. Currently it provides the following
  17258. services:
  17259. @subsubheading Prosody Service
  17260. @deffn {Scheme Variable} prosody-service-type
  17261. This is the type for the @uref{https://prosody.im, Prosody XMPP
  17262. communication server}. Its value must be a @code{prosody-configuration}
  17263. record as in this example:
  17264. @lisp
  17265. (service prosody-service-type
  17266. (prosody-configuration
  17267. (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
  17268. (int-components
  17269. (list
  17270. (int-component-configuration
  17271. (hostname "conference.example.net")
  17272. (plugin "muc")
  17273. (mod-muc (mod-muc-configuration)))))
  17274. (virtualhosts
  17275. (list
  17276. (virtualhost-configuration
  17277. (domain "example.net"))))))
  17278. @end lisp
  17279. See below for details about @code{prosody-configuration}.
  17280. @end deffn
  17281. By default, Prosody does not need much configuration. Only one
  17282. @code{virtualhosts} field is needed: it specifies the domain you wish
  17283. Prosody to serve.
  17284. You can perform various sanity checks on the generated configuration
  17285. with the @code{prosodyctl check} command.
  17286. Prosodyctl will also help you to import certificates from the
  17287. @code{letsencrypt} directory so that the @code{prosody} user can access
  17288. them. See @url{https://prosody.im/doc/letsencrypt}.
  17289. @example
  17290. prosodyctl --root cert import /etc/letsencrypt/live
  17291. @end example
  17292. The available configuration parameters follow. Each parameter
  17293. definition is preceded by its type; for example, @samp{string-list foo}
  17294. indicates that the @code{foo} parameter should be specified as a list of
  17295. strings. Types starting with @code{maybe-} denote parameters that won't
  17296. show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
  17297. There is also a way to specify the configuration as a string, if you
  17298. have an old @code{prosody.cfg.lua} file that you want to port over from
  17299. some other system; see the end for more details.
  17300. The @code{file-object} type designates either a file-like object
  17301. (@pxref{G-Expressions, file-like objects}) or a file name.
  17302. @c The following documentation was initially generated by
  17303. @c (generate-documentation) in (gnu services messaging). Manually maintained
  17304. @c documentation is better, so we shouldn't hesitate to edit below as
  17305. @c needed. However if the change you want to make to this documentation
  17306. @c can be done in an automated way, it's probably easier to change
  17307. @c (generate-documentation) than to make it below and have to deal with
  17308. @c the churn as Prosody updates.
  17309. Available @code{prosody-configuration} fields are:
  17310. @deftypevr {@code{prosody-configuration} parameter} package prosody
  17311. The Prosody package.
  17312. @end deftypevr
  17313. @deftypevr {@code{prosody-configuration} parameter} file-name data-path
  17314. Location of the Prosody data storage directory. See
  17315. @url{https://prosody.im/doc/configure}.
  17316. Defaults to @samp{"/var/lib/prosody"}.
  17317. @end deftypevr
  17318. @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
  17319. Additional plugin directories. They are searched in all the specified
  17320. paths in order. See @url{https://prosody.im/doc/plugins_directory}.
  17321. Defaults to @samp{()}.
  17322. @end deftypevr
  17323. @deftypevr {@code{prosody-configuration} parameter} file-name certificates
  17324. Every virtual host and component needs a certificate so that clients and
  17325. servers can securely verify its identity. Prosody will automatically load
  17326. certificates/keys from the directory specified here.
  17327. Defaults to @samp{"/etc/prosody/certs"}.
  17328. @end deftypevr
  17329. @deftypevr {@code{prosody-configuration} parameter} string-list admins
  17330. This is a list of accounts that are admins for the server. Note that you
  17331. must create the accounts separately. See @url{https://prosody.im/doc/admins} and
  17332. @url{https://prosody.im/doc/creating_accounts}.
  17333. Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
  17334. Defaults to @samp{()}.
  17335. @end deftypevr
  17336. @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
  17337. Enable use of libevent for better performance under high load. See
  17338. @url{https://prosody.im/doc/libevent}.
  17339. Defaults to @samp{#f}.
  17340. @end deftypevr
  17341. @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
  17342. This is the list of modules Prosody will load on startup. It looks for
  17343. @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
  17344. Documentation on modules can be found at:
  17345. @url{https://prosody.im/doc/modules}.
  17346. Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
  17347. @end deftypevr
  17348. @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
  17349. @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
  17350. should you want to disable them then add them to this list.
  17351. Defaults to @samp{()}.
  17352. @end deftypevr
  17353. @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
  17354. Path to a text file where the shared groups are defined. If this path is
  17355. empty then @samp{mod_groups} does nothing. See
  17356. @url{https://prosody.im/doc/modules/mod_groups}.
  17357. Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
  17358. @end deftypevr
  17359. @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
  17360. Disable account creation by default, for security. See
  17361. @url{https://prosody.im/doc/creating_accounts}.
  17362. Defaults to @samp{#f}.
  17363. @end deftypevr
  17364. @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
  17365. These are the SSL/TLS-related settings. Most of them are disabled so to
  17366. use Prosody's defaults. If you do not completely understand these options, do
  17367. not add them to your config, it is easy to lower the security of your server
  17368. using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
  17369. Available @code{ssl-configuration} fields are:
  17370. @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
  17371. This determines what handshake to use.
  17372. @end deftypevr
  17373. @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
  17374. Path to your private key file.
  17375. @end deftypevr
  17376. @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
  17377. Path to your certificate file.
  17378. @end deftypevr
  17379. @deftypevr {@code{ssl-configuration} parameter} file-object capath
  17380. Path to directory containing root certificates that you wish Prosody to
  17381. trust when verifying the certificates of remote servers.
  17382. Defaults to @samp{"/etc/ssl/certs"}.
  17383. @end deftypevr
  17384. @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
  17385. Path to a file containing root certificates that you wish Prosody to trust.
  17386. Similar to @code{capath} but with all certificates concatenated together.
  17387. @end deftypevr
  17388. @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
  17389. A list of verification options (these mostly map to OpenSSL's
  17390. @code{set_verify()} flags).
  17391. @end deftypevr
  17392. @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
  17393. A list of general options relating to SSL/TLS@. These map to OpenSSL's
  17394. @code{set_options()}. For a full list of options available in LuaSec, see the
  17395. LuaSec source.
  17396. @end deftypevr
  17397. @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
  17398. How long a chain of certificate authorities to check when looking for a
  17399. trusted root certificate.
  17400. @end deftypevr
  17401. @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
  17402. An OpenSSL cipher string. This selects what ciphers Prosody will offer to
  17403. clients, and in what order.
  17404. @end deftypevr
  17405. @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
  17406. A path to a file containing parameters for Diffie-Hellman key exchange. You
  17407. can create such a file with:
  17408. @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
  17409. @end deftypevr
  17410. @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
  17411. Curve for Elliptic curve Diffie-Hellman. Prosody's default is
  17412. @samp{"secp384r1"}.
  17413. @end deftypevr
  17414. @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
  17415. A list of ``extra'' verification options.
  17416. @end deftypevr
  17417. @deftypevr {@code{ssl-configuration} parameter} maybe-string password
  17418. Password for encrypted private keys.
  17419. @end deftypevr
  17420. @end deftypevr
  17421. @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
  17422. Whether to force all client-to-server connections to be encrypted or not.
  17423. See @url{https://prosody.im/doc/modules/mod_tls}.
  17424. Defaults to @samp{#f}.
  17425. @end deftypevr
  17426. @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
  17427. Set of mechanisms that will never be offered. See
  17428. @url{https://prosody.im/doc/modules/mod_saslauth}.
  17429. Defaults to @samp{("DIGEST-MD5")}.
  17430. @end deftypevr
  17431. @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
  17432. Whether to force all server-to-server connections to be encrypted or not.
  17433. See @url{https://prosody.im/doc/modules/mod_tls}.
  17434. Defaults to @samp{#f}.
  17435. @end deftypevr
  17436. @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
  17437. Whether to require encryption and certificate authentication. This
  17438. provides ideal security, but requires servers you communicate with to support
  17439. encryption AND present valid, trusted certificates. See
  17440. @url{https://prosody.im/doc/s2s#security}.
  17441. Defaults to @samp{#f}.
  17442. @end deftypevr
  17443. @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
  17444. Many servers don't support encryption or have invalid or self-signed
  17445. certificates. You can list domains here that will not be required to
  17446. authenticate using certificates. They will be authenticated using DNS@. See
  17447. @url{https://prosody.im/doc/s2s#security}.
  17448. Defaults to @samp{()}.
  17449. @end deftypevr
  17450. @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
  17451. Even if you leave @code{s2s-secure-auth?} disabled, you can still require
  17452. valid certificates for some domains by specifying a list here. See
  17453. @url{https://prosody.im/doc/s2s#security}.
  17454. Defaults to @samp{()}.
  17455. @end deftypevr
  17456. @deftypevr {@code{prosody-configuration} parameter} string authentication
  17457. Select the authentication backend to use. The default provider stores
  17458. passwords in plaintext and uses Prosody's configured data storage to store the
  17459. authentication data. If you do not trust your server please see
  17460. @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
  17461. about using the hashed backend. See also
  17462. @url{https://prosody.im/doc/authentication}
  17463. Defaults to @samp{"internal_plain"}.
  17464. @end deftypevr
  17465. @deftypevr {@code{prosody-configuration} parameter} maybe-string log
  17466. Set logging options. Advanced logging configuration is not yet supported
  17467. by the Prosody service. See @url{https://prosody.im/doc/logging}.
  17468. Defaults to @samp{"*syslog"}.
  17469. @end deftypevr
  17470. @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
  17471. File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
  17472. Defaults to @samp{"/var/run/prosody/prosody.pid"}.
  17473. @end deftypevr
  17474. @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
  17475. Maximum allowed size of the HTTP body (in bytes).
  17476. @end deftypevr
  17477. @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
  17478. Some modules expose their own URL in various ways. This URL is built
  17479. from the protocol, host and port used. If Prosody sits behind a proxy, the
  17480. public URL will be @code{http-external-url} instead. See
  17481. @url{https://prosody.im/doc/http#external_url}.
  17482. @end deftypevr
  17483. @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
  17484. A host in Prosody is a domain on which user accounts can be created. For
  17485. example if you want your users to have addresses like
  17486. @samp{"john.smith@@example.com"} then you need to add a host
  17487. @samp{"example.com"}. All options in this list will apply only to this host.
  17488. Note: the name @emph{virtual} host is used in configuration to avoid confusion with
  17489. the actual physical host that Prosody is installed on. A single Prosody
  17490. instance can serve many domains, each one defined as a VirtualHost entry in
  17491. Prosody's configuration. Conversely a server that hosts a single domain would
  17492. have just one VirtualHost entry.
  17493. See @url{https://prosody.im/doc/configure#virtual_host_settings}.
  17494. Available @code{virtualhost-configuration} fields are:
  17495. 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:
  17496. @deftypevr {@code{virtualhost-configuration} parameter} string domain
  17497. Domain you wish Prosody to serve.
  17498. @end deftypevr
  17499. @end deftypevr
  17500. @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
  17501. Components are extra services on a server which are available to clients,
  17502. usually on a subdomain of the main server (such as
  17503. @samp{"mycomponent.example.com"}). Example components might be chatroom
  17504. servers, user directories, or gateways to other protocols.
  17505. Internal components are implemented with Prosody-specific plugins. To add an
  17506. internal component, you simply fill the hostname field, and the plugin you wish
  17507. to use for the component.
  17508. See @url{https://prosody.im/doc/components}.
  17509. Defaults to @samp{()}.
  17510. Available @code{int-component-configuration} fields are:
  17511. 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:
  17512. @deftypevr {@code{int-component-configuration} parameter} string hostname
  17513. Hostname of the component.
  17514. @end deftypevr
  17515. @deftypevr {@code{int-component-configuration} parameter} string plugin
  17516. Plugin you wish to use for the component.
  17517. @end deftypevr
  17518. @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
  17519. Multi-user chat (MUC) is Prosody's module for allowing you to create
  17520. hosted chatrooms/conferences for XMPP users.
  17521. General information on setting up and using multi-user chatrooms can be found
  17522. in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
  17523. which you should read if you are new to XMPP chatrooms.
  17524. See also @url{https://prosody.im/doc/modules/mod_muc}.
  17525. Available @code{mod-muc-configuration} fields are:
  17526. @deftypevr {@code{mod-muc-configuration} parameter} string name
  17527. The name to return in service discovery responses.
  17528. Defaults to @samp{"Prosody Chatrooms"}.
  17529. @end deftypevr
  17530. @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
  17531. If @samp{#t}, this will only allow admins to create new chatrooms.
  17532. Otherwise anyone can create a room. The value @samp{"local"} restricts room
  17533. creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
  17534. can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
  17535. restricts to service administrators only.
  17536. Defaults to @samp{#f}.
  17537. @end deftypevr
  17538. @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
  17539. Maximum number of history messages that will be sent to the member that has
  17540. just joined the room.
  17541. Defaults to @samp{20}.
  17542. @end deftypevr
  17543. @end deftypevr
  17544. @end deftypevr
  17545. @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
  17546. External components use XEP-0114, which most standalone components
  17547. support. To add an external component, you simply fill the hostname field. See
  17548. @url{https://prosody.im/doc/components}.
  17549. Defaults to @samp{()}.
  17550. Available @code{ext-component-configuration} fields are:
  17551. 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:
  17552. @deftypevr {@code{ext-component-configuration} parameter} string component-secret
  17553. Password which the component will use to log in.
  17554. @end deftypevr
  17555. @deftypevr {@code{ext-component-configuration} parameter} string hostname
  17556. Hostname of the component.
  17557. @end deftypevr
  17558. @end deftypevr
  17559. @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
  17560. Port(s) Prosody listens on for component connections.
  17561. Defaults to @samp{(5347)}.
  17562. @end deftypevr
  17563. @deftypevr {@code{prosody-configuration} parameter} string component-interface
  17564. Interface Prosody listens on for component connections.
  17565. Defaults to @samp{"127.0.0.1"}.
  17566. @end deftypevr
  17567. @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
  17568. Raw content that will be added to the configuration file.
  17569. @end deftypevr
  17570. It could be that you just want to get a @code{prosody.cfg.lua}
  17571. up and running. In that case, you can pass an
  17572. @code{opaque-prosody-configuration} record as the value of
  17573. @code{prosody-service-type}. As its name indicates, an opaque configuration
  17574. does not have easy reflective capabilities.
  17575. Available @code{opaque-prosody-configuration} fields are:
  17576. @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
  17577. The prosody package.
  17578. @end deftypevr
  17579. @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
  17580. The contents of the @code{prosody.cfg.lua} to use.
  17581. @end deftypevr
  17582. For example, if your @code{prosody.cfg.lua} is just the empty
  17583. string, you could instantiate a prosody service like this:
  17584. @lisp
  17585. (service prosody-service-type
  17586. (opaque-prosody-configuration
  17587. (prosody.cfg.lua "")))
  17588. @end lisp
  17589. @c end of Prosody auto-generated documentation
  17590. @subsubheading BitlBee Service
  17591. @cindex IRC (Internet Relay Chat)
  17592. @cindex IRC gateway
  17593. @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
  17594. interface to a variety of messaging protocols such as XMPP.
  17595. @defvr {Scheme Variable} bitlbee-service-type
  17596. This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
  17597. gateway daemon. Its value is a @code{bitlbee-configuration} (see
  17598. below).
  17599. To have BitlBee listen on port 6667 on localhost, add this line to your
  17600. services:
  17601. @lisp
  17602. (service bitlbee-service-type)
  17603. @end lisp
  17604. @end defvr
  17605. @deftp {Data Type} bitlbee-configuration
  17606. This is the configuration for BitlBee, with the following fields:
  17607. @table @asis
  17608. @item @code{interface} (default: @code{"127.0.0.1"})
  17609. @itemx @code{port} (default: @code{6667})
  17610. Listen on the network interface corresponding to the IP address
  17611. specified in @var{interface}, on @var{port}.
  17612. When @var{interface} is @code{127.0.0.1}, only local clients can
  17613. connect; when it is @code{0.0.0.0}, connections can come from any
  17614. networking interface.
  17615. @item @code{bitlbee} (default: @code{bitlbee})
  17616. The BitlBee package to use.
  17617. @item @code{plugins} (default: @code{'()})
  17618. List of plugin packages to use---e.g., @code{bitlbee-discord}.
  17619. @item @code{extra-settings} (default: @code{""})
  17620. Configuration snippet added as-is to the BitlBee configuration file.
  17621. @end table
  17622. @end deftp
  17623. @subsubheading Quassel Service
  17624. @cindex IRC (Internet Relay Chat)
  17625. @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
  17626. meaning that one or more clients can attach to and detach from the
  17627. central core.
  17628. @defvr {Scheme Variable} quassel-service-type
  17629. This is the service type for the @url{https://quassel-irc.org/,Quassel}
  17630. IRC backend daemon. Its value is a @code{quassel-configuration}
  17631. (see below).
  17632. @end defvr
  17633. @deftp {Data Type} quassel-configuration
  17634. This is the configuration for Quassel, with the following fields:
  17635. @table @asis
  17636. @item @code{quassel} (default: @code{quassel})
  17637. The Quassel package to use.
  17638. @item @code{interface} (default: @code{"::,0.0.0.0"})
  17639. @item @code{port} (default: @code{4242})
  17640. Listen on the network interface(s) corresponding to the IPv4 or IPv6
  17641. interfaces specified in the comma delimited @var{interface}, on
  17642. @var{port}.
  17643. @item @code{loglevel} (default: @code{"Info"})
  17644. The level of logging desired. Accepted values are Debug, Info, Warning
  17645. and Error.
  17646. @end table
  17647. @end deftp
  17648. @node Telephony Services
  17649. @subsection Telephony Services
  17650. @cindex Murmur (VoIP server)
  17651. @cindex VoIP server
  17652. This section describes how to set up and run a Murmur server. Murmur is
  17653. the server of the @uref{https://mumble.info, Mumble} voice-over-IP
  17654. (VoIP) suite.
  17655. @deftp {Data Type} murmur-configuration
  17656. The service type for the Murmur server. An example configuration can
  17657. look like this:
  17658. @lisp
  17659. (service murmur-service-type
  17660. (murmur-configuration
  17661. (welcome-text
  17662. "Welcome to this Mumble server running on Guix!")
  17663. (cert-required? #t) ;disallow text password logins
  17664. (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
  17665. (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
  17666. @end lisp
  17667. After reconfiguring your system, you can manually set the murmur @code{SuperUser}
  17668. password with the command that is printed during the activation phase.
  17669. It is recommended to register a normal Mumble user account
  17670. and grant it admin or moderator rights.
  17671. You can use the @code{mumble} client to
  17672. login as new normal user, register yourself, and log out.
  17673. For the next step login with the name @code{SuperUser} use
  17674. the @code{SuperUser} password that you set previously,
  17675. and grant your newly registered mumble user administrator or moderator
  17676. rights and create some channels.
  17677. Available @code{murmur-configuration} fields are:
  17678. @table @asis
  17679. @item @code{package} (default: @code{mumble})
  17680. Package that contains @code{bin/murmurd}.
  17681. @item @code{user} (default: @code{"murmur"})
  17682. User who will run the Murmur server.
  17683. @item @code{group} (default: @code{"murmur"})
  17684. Group of the user who will run the murmur server.
  17685. @item @code{port} (default: @code{64738})
  17686. Port on which the server will listen.
  17687. @item @code{welcome-text} (default: @code{""})
  17688. Welcome text sent to clients when they connect.
  17689. @item @code{server-password} (default: @code{""})
  17690. Password the clients have to enter in order to connect.
  17691. @item @code{max-users} (default: @code{100})
  17692. Maximum of users that can be connected to the server at once.
  17693. @item @code{max-user-bandwidth} (default: @code{#f})
  17694. Maximum voice traffic a user can send per second.
  17695. @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
  17696. File name of the sqlite database.
  17697. The service's user will become the owner of the directory.
  17698. @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
  17699. File name of the log file.
  17700. The service's user will become the owner of the directory.
  17701. @item @code{autoban-attempts} (default: @code{10})
  17702. Maximum number of logins a user can make in @code{autoban-timeframe}
  17703. without getting auto banned for @code{autoban-time}.
  17704. @item @code{autoban-timeframe} (default: @code{120})
  17705. Timeframe for autoban in seconds.
  17706. @item @code{autoban-time} (default: @code{300})
  17707. Amount of time in seconds for which a client gets banned
  17708. when violating the autoban limits.
  17709. @item @code{opus-threshold} (default: @code{100})
  17710. Percentage of clients that need to support opus
  17711. before switching over to opus audio codec.
  17712. @item @code{channel-nesting-limit} (default: @code{10})
  17713. How deep channels can be nested at maximum.
  17714. @item @code{channelname-regex} (default: @code{#f})
  17715. A string in form of a Qt regular expression that channel names must conform to.
  17716. @item @code{username-regex} (default: @code{#f})
  17717. A string in form of a Qt regular expression that user names must conform to.
  17718. @item @code{text-message-length} (default: @code{5000})
  17719. Maximum size in bytes that a user can send in one text chat message.
  17720. @item @code{image-message-length} (default: @code{(* 128 1024)})
  17721. Maximum size in bytes that a user can send in one image message.
  17722. @item @code{cert-required?} (default: @code{#f})
  17723. If it is set to @code{#t} clients that use weak password authentication
  17724. will not be accepted. Users must have completed the certificate wizard to join.
  17725. @item @code{remember-channel?} (default: @code{#f})
  17726. Should murmur remember the last channel each user was in when they disconnected
  17727. and put them into the remembered channel when they rejoin.
  17728. @item @code{allow-html?} (default: @code{#f})
  17729. Should html be allowed in text messages, user comments, and channel descriptions.
  17730. @item @code{allow-ping?} (default: @code{#f})
  17731. Setting to true exposes the current user count, the maximum user count, and
  17732. the server's maximum bandwidth per client to unauthenticated users. In the
  17733. Mumble client, this information is shown in the Connect dialog.
  17734. Disabling this setting will prevent public listing of the server.
  17735. @item @code{bonjour?} (default: @code{#f})
  17736. Should the server advertise itself in the local network through the bonjour protocol.
  17737. @item @code{send-version?} (default: @code{#f})
  17738. Should the murmur server version be exposed in ping requests.
  17739. @item @code{log-days} (default: @code{31})
  17740. Murmur also stores logs in the database, which are accessible via RPC.
  17741. The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
  17742. or -1 to disable logging to the database.
  17743. @item @code{obfuscate-ips?} (default: @code{#t})
  17744. Should logged ips be obfuscated to protect the privacy of users.
  17745. @item @code{ssl-cert} (default: @code{#f})
  17746. File name of the SSL/TLS certificate used for encrypted connections.
  17747. @lisp
  17748. (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
  17749. @end lisp
  17750. @item @code{ssl-key} (default: @code{#f})
  17751. Filepath to the ssl private key used for encrypted connections.
  17752. @lisp
  17753. (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
  17754. @end lisp
  17755. @item @code{ssl-dh-params} (default: @code{#f})
  17756. File name of a PEM-encoded file with Diffie-Hellman parameters
  17757. for the SSL/TLS encryption. Alternatively you set it to
  17758. @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
  17759. or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
  17760. @item @code{ssl-ciphers} (default: @code{#f})
  17761. The @code{ssl-ciphers} option chooses the cipher suites to make available for use
  17762. in SSL/TLS.
  17763. This option is specified using
  17764. @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
  17765. OpenSSL cipher list notation}.
  17766. It is recommended that you try your cipher string using 'openssl ciphers <string>'
  17767. before setting it here, to get a feel for which cipher suites you will get.
  17768. After setting this option, it is recommend that you inspect your Murmur log
  17769. to ensure that Murmur is using the cipher suites that you expected it to.
  17770. Note: Changing this option may impact the backwards compatibility of your
  17771. Murmur server, and can remove the ability for older Mumble clients to be able
  17772. to connect to it.
  17773. @item @code{public-registration} (default: @code{#f})
  17774. Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
  17775. You can optionally register your server in the public server list that the
  17776. @code{mumble} client shows on startup.
  17777. You cannot register your server if you have set a @code{server-password},
  17778. or set @code{allow-ping} to @code{#f}.
  17779. It might take a few hours until it shows up in the public list.
  17780. @item @code{file} (default: @code{#f})
  17781. Optional alternative override for this configuration.
  17782. @end table
  17783. @end deftp
  17784. @deftp {Data Type} murmur-public-registration-configuration
  17785. Configuration for public registration of a murmur service.
  17786. @table @asis
  17787. @item @code{name}
  17788. This is a display name for your server. Not to be confused with the hostname.
  17789. @item @code{password}
  17790. A password to identify your registration.
  17791. Subsequent updates will need the same password. Don't lose your password.
  17792. @item @code{url}
  17793. This should be a @code{http://} or @code{https://} link to your web
  17794. site.
  17795. @item @code{hostname} (default: @code{#f})
  17796. By default your server will be listed by its IP address.
  17797. If it is set your server will be linked by this host name instead.
  17798. @end table
  17799. @end deftp
  17800. @node Monitoring Services
  17801. @subsection Monitoring Services
  17802. @subsubheading Tailon Service
  17803. @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
  17804. viewing and searching log files.
  17805. The following example will configure the service with default values.
  17806. By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
  17807. @lisp
  17808. (service tailon-service-type)
  17809. @end lisp
  17810. The following example customises more of the Tailon configuration,
  17811. adding @command{sed} to the list of allowed commands.
  17812. @lisp
  17813. (service tailon-service-type
  17814. (tailon-configuration
  17815. (config-file
  17816. (tailon-configuration-file
  17817. (allowed-commands '("tail" "grep" "awk" "sed"))))))
  17818. @end lisp
  17819. @deftp {Data Type} tailon-configuration
  17820. Data type representing the configuration of Tailon.
  17821. This type has the following parameters:
  17822. @table @asis
  17823. @item @code{config-file} (default: @code{(tailon-configuration-file)})
  17824. The configuration file to use for Tailon. This can be set to a
  17825. @dfn{tailon-configuration-file} record value, or any gexp
  17826. (@pxref{G-Expressions}).
  17827. For example, to instead use a local file, the @code{local-file} function
  17828. can be used:
  17829. @lisp
  17830. (service tailon-service-type
  17831. (tailon-configuration
  17832. (config-file (local-file "./my-tailon.conf"))))
  17833. @end lisp
  17834. @item @code{package} (default: @code{tailon})
  17835. The tailon package to use.
  17836. @end table
  17837. @end deftp
  17838. @deftp {Data Type} tailon-configuration-file
  17839. Data type representing the configuration options for Tailon.
  17840. This type has the following parameters:
  17841. @table @asis
  17842. @item @code{files} (default: @code{(list "/var/log")})
  17843. List of files to display. The list can include strings for a single file
  17844. or directory, or a list, where the first item is the name of a
  17845. subsection, and the remaining items are the files or directories in that
  17846. subsection.
  17847. @item @code{bind} (default: @code{"localhost:8080"})
  17848. Address and port to which Tailon should bind on.
  17849. @item @code{relative-root} (default: @code{#f})
  17850. URL path to use for Tailon, set to @code{#f} to not use a path.
  17851. @item @code{allow-transfers?} (default: @code{#t})
  17852. Allow downloading the log files in the web interface.
  17853. @item @code{follow-names?} (default: @code{#t})
  17854. Allow tailing of not-yet existent files.
  17855. @item @code{tail-lines} (default: @code{200})
  17856. Number of lines to read initially from each file.
  17857. @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
  17858. Commands to allow running. By default, @code{sed} is disabled.
  17859. @item @code{debug?} (default: @code{#f})
  17860. Set @code{debug?} to @code{#t} to show debug messages.
  17861. @item @code{wrap-lines} (default: @code{#t})
  17862. Initial line wrapping state in the web interface. Set to @code{#t} to
  17863. initially wrap lines (the default), or to @code{#f} to initially not
  17864. wrap lines.
  17865. @item @code{http-auth} (default: @code{#f})
  17866. HTTP authentication type to use. Set to @code{#f} to disable
  17867. authentication (the default). Supported values are @code{"digest"} or
  17868. @code{"basic"}.
  17869. @item @code{users} (default: @code{#f})
  17870. If HTTP authentication is enabled (see @code{http-auth}), access will be
  17871. restricted to the credentials provided here. To configure users, use a
  17872. list of pairs, where the first element of the pair is the username, and
  17873. the 2nd element of the pair is the password.
  17874. @lisp
  17875. (tailon-configuration-file
  17876. (http-auth "basic")
  17877. (users '(("user1" . "password1")
  17878. ("user2" . "password2"))))
  17879. @end lisp
  17880. @end table
  17881. @end deftp
  17882. @subsubheading Darkstat Service
  17883. @cindex darkstat
  17884. Darkstat is a packet sniffer that captures network traffic, calculates
  17885. statistics about usage, and serves reports over HTTP.
  17886. @defvar {Scheme Variable} darkstat-service-type
  17887. This is the service type for the
  17888. @uref{https://unix4lyfe.org/darkstat/, darkstat}
  17889. service, its value must be a @code{darkstat-configuration} record as in
  17890. this example:
  17891. @lisp
  17892. (service darkstat-service-type
  17893. (darkstat-configuration
  17894. (interface "eno1")))
  17895. @end lisp
  17896. @end defvar
  17897. @deftp {Data Type} darkstat-configuration
  17898. Data type representing the configuration of @command{darkstat}.
  17899. @table @asis
  17900. @item @code{package} (default: @code{darkstat})
  17901. The darkstat package to use.
  17902. @item @code{interface}
  17903. Capture traffic on the specified network interface.
  17904. @item @code{port} (default: @code{"667"})
  17905. Bind the web interface to the specified port.
  17906. @item @code{bind-address} (default: @code{"127.0.0.1"})
  17907. Bind the web interface to the specified address.
  17908. @item @code{base} (default: @code{"/"})
  17909. Specify the path of the base URL@. This can be useful if
  17910. @command{darkstat} is accessed via a reverse proxy.
  17911. @end table
  17912. @end deftp
  17913. @subsubheading Prometheus Node Exporter Service
  17914. @cindex prometheus-node-exporter
  17915. The Prometheus ``node exporter'' makes hardware and operating system statistics
  17916. provided by the Linux kernel available for the Prometheus monitoring system.
  17917. This service should be deployed on all physical nodes and virtual machines,
  17918. where monitoring these statistics is desirable.
  17919. @defvar {Scheme variable} prometheus-node-exporter-service-type
  17920. This is the service type for the
  17921. @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
  17922. service, its value must be a @code{prometheus-node-exporter-configuration}.
  17923. @lisp
  17924. (service prometheus-node-exporter-service-type)
  17925. @end lisp
  17926. @end defvar
  17927. @deftp {Data Type} prometheus-node-exporter-configuration
  17928. Data type representing the configuration of @command{node_exporter}.
  17929. @table @asis
  17930. @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
  17931. The prometheus-node-exporter package to use.
  17932. @item @code{web-listen-address} (default: @code{":9100"})
  17933. Bind the web interface to the specified address.
  17934. @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
  17935. This directory can be used to export metrics specific to this machine.
  17936. Files containing metrics in the text format, with the filename ending in
  17937. @code{.prom} should be placed in this directory.
  17938. @item @code{extra-options} (default: @code{'()})
  17939. Extra options to pass to the Prometheus node exporter.
  17940. @end table
  17941. @end deftp
  17942. @subsubheading Zabbix server
  17943. @cindex zabbix zabbix-server
  17944. Zabbix provides monitoring metrics, among others network utilization, CPU load
  17945. and disk space consumption:
  17946. @itemize
  17947. @item High performance, high capacity (able to monitor hundreds of thousands of devices).
  17948. @item Auto-discovery of servers and network devices and interfaces.
  17949. @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
  17950. @item Distributed monitoring with centralized web administration.
  17951. @item Native high performance agents.
  17952. @item SLA, and ITIL KPI metrics on reporting.
  17953. @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
  17954. @item Remote command execution through Zabbix proxies.
  17955. @end itemize
  17956. @c %start of fragment
  17957. Available @code{zabbix-server-configuration} fields are:
  17958. @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
  17959. The zabbix-server package.
  17960. @end deftypevr
  17961. @deftypevr {@code{zabbix-server-configuration} parameter} string user
  17962. User who will run the Zabbix server.
  17963. Defaults to @samp{"zabbix"}.
  17964. @end deftypevr
  17965. @deftypevr {@code{zabbix-server-configuration} parameter} group group
  17966. Group who will run the Zabbix server.
  17967. Defaults to @samp{"zabbix"}.
  17968. @end deftypevr
  17969. @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
  17970. Database host name.
  17971. Defaults to @samp{"127.0.0.1"}.
  17972. @end deftypevr
  17973. @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
  17974. Database name.
  17975. Defaults to @samp{"zabbix"}.
  17976. @end deftypevr
  17977. @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
  17978. Database user.
  17979. Defaults to @samp{"zabbix"}.
  17980. @end deftypevr
  17981. @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
  17982. Database password. Please, use @code{include-files} with
  17983. @code{DBPassword=SECRET} inside a specified file instead.
  17984. Defaults to @samp{""}.
  17985. @end deftypevr
  17986. @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
  17987. Database port.
  17988. Defaults to @samp{5432}.
  17989. @end deftypevr
  17990. @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
  17991. Specifies where log messages are written to:
  17992. @itemize @bullet
  17993. @item
  17994. @code{system} - syslog.
  17995. @item
  17996. @code{file} - file specified with @code{log-file} parameter.
  17997. @item
  17998. @code{console} - standard output.
  17999. @end itemize
  18000. Defaults to @samp{""}.
  18001. @end deftypevr
  18002. @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
  18003. Log file name for @code{log-type} @code{file} parameter.
  18004. Defaults to @samp{"/var/log/zabbix/server.log"}.
  18005. @end deftypevr
  18006. @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
  18007. Name of PID file.
  18008. Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
  18009. @end deftypevr
  18010. @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
  18011. The location of certificate authority (CA) files for SSL server
  18012. certificate verification.
  18013. Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
  18014. @end deftypevr
  18015. @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
  18016. Location of SSL client certificates.
  18017. Defaults to @samp{"/etc/ssl/certs"}.
  18018. @end deftypevr
  18019. @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
  18020. Extra options will be appended to Zabbix server configuration file.
  18021. Defaults to @samp{""}.
  18022. @end deftypevr
  18023. @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
  18024. You may include individual files or all files in a directory in the
  18025. configuration file.
  18026. Defaults to @samp{()}.
  18027. @end deftypevr
  18028. @c %end of fragment
  18029. @subsubheading Zabbix agent
  18030. @cindex zabbix zabbix-agent
  18031. Zabbix agent gathers information for Zabbix server.
  18032. @c %start of fragment
  18033. Available @code{zabbix-agent-configuration} fields are:
  18034. @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
  18035. The zabbix-agent package.
  18036. @end deftypevr
  18037. @deftypevr {@code{zabbix-agent-configuration} parameter} string user
  18038. User who will run the Zabbix agent.
  18039. Defaults to @samp{"zabbix"}.
  18040. @end deftypevr
  18041. @deftypevr {@code{zabbix-agent-configuration} parameter} group group
  18042. Group who will run the Zabbix agent.
  18043. Defaults to @samp{"zabbix"}.
  18044. @end deftypevr
  18045. @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
  18046. Unique, case sensitive hostname which is required for active checks and
  18047. must match hostname as configured on the server.
  18048. Defaults to @samp{""}.
  18049. @end deftypevr
  18050. @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
  18051. Specifies where log messages are written to:
  18052. @itemize @bullet
  18053. @item
  18054. @code{system} - syslog.
  18055. @item
  18056. @code{file} - file specified with @code{log-file} parameter.
  18057. @item
  18058. @code{console} - standard output.
  18059. @end itemize
  18060. Defaults to @samp{""}.
  18061. @end deftypevr
  18062. @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
  18063. Log file name for @code{log-type} @code{file} parameter.
  18064. Defaults to @samp{"/var/log/zabbix/agent.log"}.
  18065. @end deftypevr
  18066. @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
  18067. Name of PID file.
  18068. Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
  18069. @end deftypevr
  18070. @deftypevr {@code{zabbix-agent-configuration} parameter} list server
  18071. List of IP addresses, optionally in CIDR notation, or hostnames of
  18072. Zabbix servers and Zabbix proxies. Incoming connections will be
  18073. accepted only from the hosts listed here.
  18074. Defaults to @samp{("127.0.0.1")}.
  18075. @end deftypevr
  18076. @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
  18077. List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
  18078. proxies for active checks. If port is not specified, default port is
  18079. used. If this parameter is not specified, active checks are disabled.
  18080. Defaults to @samp{("127.0.0.1")}.
  18081. @end deftypevr
  18082. @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
  18083. Extra options will be appended to Zabbix server configuration file.
  18084. Defaults to @samp{""}.
  18085. @end deftypevr
  18086. @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
  18087. You may include individual files or all files in a directory in the
  18088. configuration file.
  18089. Defaults to @samp{()}.
  18090. @end deftypevr
  18091. @c %end of fragment
  18092. @subsubheading Zabbix front-end
  18093. @cindex zabbix zabbix-front-end
  18094. This service provides a WEB interface to Zabbix server.
  18095. @c %start of fragment
  18096. Available @code{zabbix-front-end-configuration} fields are:
  18097. @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
  18098. NGINX configuration.
  18099. @end deftypevr
  18100. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
  18101. Database host name.
  18102. Defaults to @samp{"localhost"}.
  18103. @end deftypevr
  18104. @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
  18105. Database port.
  18106. Defaults to @samp{5432}.
  18107. @end deftypevr
  18108. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
  18109. Database name.
  18110. Defaults to @samp{"zabbix"}.
  18111. @end deftypevr
  18112. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
  18113. Database user.
  18114. Defaults to @samp{"zabbix"}.
  18115. @end deftypevr
  18116. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
  18117. Database password. Please, use @code{db-secret-file} instead.
  18118. Defaults to @samp{""}.
  18119. @end deftypevr
  18120. @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
  18121. Secret file containing the credentials for the Zabbix front-end. The value
  18122. must be a local file name, not a G-expression. You are expected to create
  18123. this file manually. Its contents will be copied into @file{zabbix.conf.php}
  18124. as the value of @code{$DB['PASSWORD']}.
  18125. Defaults to @samp{""}.
  18126. @end deftypevr
  18127. @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
  18128. Zabbix server hostname.
  18129. Defaults to @samp{"localhost"}.
  18130. @end deftypevr
  18131. @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
  18132. Zabbix server port.
  18133. Defaults to @samp{10051}.
  18134. @end deftypevr
  18135. @c %end of fragment
  18136. @node Kerberos Services
  18137. @subsection Kerberos Services
  18138. @cindex Kerberos
  18139. The @code{(gnu services kerberos)} module provides services relating to
  18140. the authentication protocol @dfn{Kerberos}.
  18141. @subsubheading Krb5 Service
  18142. Programs using a Kerberos client library normally
  18143. expect a configuration file in @file{/etc/krb5.conf}.
  18144. This service generates such a file from a definition provided in the
  18145. operating system declaration.
  18146. It does not cause any daemon to be started.
  18147. No ``keytab'' files are provided by this service---you must explicitly create them.
  18148. This service is known to work with the MIT client library, @code{mit-krb5}.
  18149. Other implementations have not been tested.
  18150. @defvr {Scheme Variable} krb5-service-type
  18151. A service type for Kerberos 5 clients.
  18152. @end defvr
  18153. @noindent
  18154. Here is an example of its use:
  18155. @lisp
  18156. (service krb5-service-type
  18157. (krb5-configuration
  18158. (default-realm "EXAMPLE.COM")
  18159. (allow-weak-crypto? #t)
  18160. (realms (list
  18161. (krb5-realm
  18162. (name "EXAMPLE.COM")
  18163. (admin-server "groucho.example.com")
  18164. (kdc "karl.example.com"))
  18165. (krb5-realm
  18166. (name "ARGRX.EDU")
  18167. (admin-server "kerb-admin.argrx.edu")
  18168. (kdc "keys.argrx.edu"))))))
  18169. @end lisp
  18170. @noindent
  18171. This example provides a Kerberos@tie{}5 client configuration which:
  18172. @itemize
  18173. @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
  18174. of which have distinct administration servers and key distribution centers;
  18175. @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
  18176. specified by clients;
  18177. @item Accepts services which only support encryption types known to be weak.
  18178. @end itemize
  18179. The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
  18180. Only the most commonly used ones are described here.
  18181. For a full list, and more detailed explanation of each, see the MIT
  18182. @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
  18183. documentation.
  18184. @deftp {Data Type} krb5-realm
  18185. @cindex realm, kerberos
  18186. @table @asis
  18187. @item @code{name}
  18188. This field is a string identifying the name of the realm.
  18189. A common convention is to use the fully qualified DNS name of your organization,
  18190. converted to upper case.
  18191. @item @code{admin-server}
  18192. This field is a string identifying the host where the administration server is
  18193. running.
  18194. @item @code{kdc}
  18195. This field is a string identifying the key distribution center
  18196. for the realm.
  18197. @end table
  18198. @end deftp
  18199. @deftp {Data Type} krb5-configuration
  18200. @table @asis
  18201. @item @code{allow-weak-crypto?} (default: @code{#f})
  18202. If this flag is @code{#t} then services which only offer encryption algorithms
  18203. known to be weak will be accepted.
  18204. @item @code{default-realm} (default: @code{#f})
  18205. This field should be a string identifying the default Kerberos
  18206. realm for the client.
  18207. You should set this field to the name of your Kerberos realm.
  18208. If this value is @code{#f}
  18209. then a realm must be specified with every Kerberos principal when invoking programs
  18210. such as @command{kinit}.
  18211. @item @code{realms}
  18212. This should be a non-empty list of @code{krb5-realm} objects, which clients may
  18213. access.
  18214. Normally, one of them will have a @code{name} field matching the @code{default-realm}
  18215. field.
  18216. @end table
  18217. @end deftp
  18218. @subsubheading PAM krb5 Service
  18219. @cindex pam-krb5
  18220. The @code{pam-krb5} service allows for login authentication and password
  18221. management via Kerberos.
  18222. You will need this service if you want PAM enabled applications to authenticate
  18223. users using Kerberos.
  18224. @defvr {Scheme Variable} pam-krb5-service-type
  18225. A service type for the Kerberos 5 PAM module.
  18226. @end defvr
  18227. @deftp {Data Type} pam-krb5-configuration
  18228. Data type representing the configuration of the Kerberos 5 PAM module.
  18229. This type has the following parameters:
  18230. @table @asis
  18231. @item @code{pam-krb5} (default: @code{pam-krb5})
  18232. The pam-krb5 package to use.
  18233. @item @code{minimum-uid} (default: @code{1000})
  18234. The smallest user ID for which Kerberos authentications should be attempted.
  18235. Local accounts with lower values will silently fail to authenticate.
  18236. @end table
  18237. @end deftp
  18238. @node LDAP Services
  18239. @subsection LDAP Services
  18240. @cindex LDAP
  18241. @cindex nslcd, LDAP service
  18242. The @code{(gnu services authentication)} module provides the
  18243. @code{nslcd-service-type}, which can be used to authenticate against an LDAP
  18244. server. In addition to configuring the service itself, you may want to add
  18245. @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
  18246. Switch} for detailed information.
  18247. Here is a simple operating system declaration with a default configuration of
  18248. the @code{nslcd-service-type} and a Name Service Switch configuration that
  18249. consults the @code{ldap} name service last:
  18250. @lisp
  18251. (use-service-modules authentication)
  18252. (use-modules (gnu system nss))
  18253. ...
  18254. (operating-system
  18255. ...
  18256. (services
  18257. (cons*
  18258. (service nslcd-service-type)
  18259. (service dhcp-client-service-type)
  18260. %base-services))
  18261. (name-service-switch
  18262. (let ((services (list (name-service (name "db"))
  18263. (name-service (name "files"))
  18264. (name-service (name "ldap")))))
  18265. (name-service-switch
  18266. (inherit %mdns-host-lookup-nss)
  18267. (password services)
  18268. (shadow services)
  18269. (group services)
  18270. (netgroup services)
  18271. (gshadow services)))))
  18272. @end lisp
  18273. @c %start of generated documentation for nslcd-configuration
  18274. Available @code{nslcd-configuration} fields are:
  18275. @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
  18276. The @code{nss-pam-ldapd} package to use.
  18277. @end deftypevr
  18278. @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
  18279. The number of threads to start that can handle requests and perform LDAP
  18280. queries. Each thread opens a separate connection to the LDAP server.
  18281. The default is to start 5 threads.
  18282. Defaults to @samp{disabled}.
  18283. @end deftypevr
  18284. @deftypevr {@code{nslcd-configuration} parameter} string uid
  18285. This specifies the user id with which the daemon should be run.
  18286. Defaults to @samp{"nslcd"}.
  18287. @end deftypevr
  18288. @deftypevr {@code{nslcd-configuration} parameter} string gid
  18289. This specifies the group id with which the daemon should be run.
  18290. Defaults to @samp{"nslcd"}.
  18291. @end deftypevr
  18292. @deftypevr {@code{nslcd-configuration} parameter} log-option log
  18293. This option controls the way logging is done via a list containing
  18294. SCHEME and LEVEL@. The SCHEME argument may either be the symbols
  18295. @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
  18296. argument is optional and specifies the log level. The log level may be
  18297. one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
  18298. @samp{notice}, @samp{info} or @samp{debug}. All messages with the
  18299. specified log level or higher are logged.
  18300. Defaults to @samp{("/var/log/nslcd" info)}.
  18301. @end deftypevr
  18302. @deftypevr {@code{nslcd-configuration} parameter} list uri
  18303. The list of LDAP server URIs. Normally, only the first server will be
  18304. used with the following servers as fall-back.
  18305. Defaults to @samp{("ldap://localhost:389/")}.
  18306. @end deftypevr
  18307. @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
  18308. The version of the LDAP protocol to use. The default is to use the
  18309. maximum version supported by the LDAP library.
  18310. Defaults to @samp{disabled}.
  18311. @end deftypevr
  18312. @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
  18313. Specifies the distinguished name with which to bind to the directory
  18314. server for lookups. The default is to bind anonymously.
  18315. Defaults to @samp{disabled}.
  18316. @end deftypevr
  18317. @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
  18318. Specifies the credentials with which to bind. This option is only
  18319. applicable when used with binddn.
  18320. Defaults to @samp{disabled}.
  18321. @end deftypevr
  18322. @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
  18323. Specifies the distinguished name to use when the root user tries to
  18324. modify a user's password using the PAM module.
  18325. Defaults to @samp{disabled}.
  18326. @end deftypevr
  18327. @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
  18328. Specifies the credentials with which to bind if the root user tries to
  18329. change a user's password. This option is only applicable when used with
  18330. rootpwmoddn
  18331. Defaults to @samp{disabled}.
  18332. @end deftypevr
  18333. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
  18334. Specifies the SASL mechanism to be used when performing SASL
  18335. authentication.
  18336. Defaults to @samp{disabled}.
  18337. @end deftypevr
  18338. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
  18339. Specifies the SASL realm to be used when performing SASL authentication.
  18340. Defaults to @samp{disabled}.
  18341. @end deftypevr
  18342. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
  18343. Specifies the authentication identity to be used when performing SASL
  18344. authentication.
  18345. Defaults to @samp{disabled}.
  18346. @end deftypevr
  18347. @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
  18348. Specifies the authorization identity to be used when performing SASL
  18349. authentication.
  18350. Defaults to @samp{disabled}.
  18351. @end deftypevr
  18352. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
  18353. Determines whether the LDAP server host name should be canonicalised. If
  18354. this is enabled the LDAP library will do a reverse host name lookup. By
  18355. default, it is left up to the LDAP library whether this check is
  18356. performed or not.
  18357. Defaults to @samp{disabled}.
  18358. @end deftypevr
  18359. @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
  18360. Set the name for the GSS-API Kerberos credentials cache.
  18361. Defaults to @samp{disabled}.
  18362. @end deftypevr
  18363. @deftypevr {@code{nslcd-configuration} parameter} string base
  18364. The directory search base.
  18365. Defaults to @samp{"dc=example,dc=com"}.
  18366. @end deftypevr
  18367. @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
  18368. Specifies the search scope (subtree, onelevel, base or children). The
  18369. default scope is subtree; base scope is almost never useful for name
  18370. service lookups; children scope is not supported on all servers.
  18371. Defaults to @samp{(subtree)}.
  18372. @end deftypevr
  18373. @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
  18374. Specifies the policy for dereferencing aliases. The default policy is
  18375. to never dereference aliases.
  18376. Defaults to @samp{disabled}.
  18377. @end deftypevr
  18378. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
  18379. Specifies whether automatic referral chasing should be enabled. The
  18380. default behaviour is to chase referrals.
  18381. Defaults to @samp{disabled}.
  18382. @end deftypevr
  18383. @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
  18384. This option allows for custom attributes to be looked up instead of the
  18385. default RFC 2307 attributes. It is a list of maps, each consisting of
  18386. the name of a map, the RFC 2307 attribute to match and the query
  18387. expression for the attribute as it is available in the directory.
  18388. Defaults to @samp{()}.
  18389. @end deftypevr
  18390. @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
  18391. A list of filters consisting of the name of a map to which the filter
  18392. applies and an LDAP search filter expression.
  18393. Defaults to @samp{()}.
  18394. @end deftypevr
  18395. @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
  18396. Specifies the time limit in seconds to use when connecting to the
  18397. directory server. The default value is 10 seconds.
  18398. Defaults to @samp{disabled}.
  18399. @end deftypevr
  18400. @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
  18401. Specifies the time limit (in seconds) to wait for a response from the
  18402. LDAP server. A value of zero, which is the default, is to wait
  18403. indefinitely for searches to be completed.
  18404. Defaults to @samp{disabled}.
  18405. @end deftypevr
  18406. @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
  18407. Specifies the period if inactivity (in seconds) after which the con‐
  18408. nection to the LDAP server will be closed. The default is not to time
  18409. out connections.
  18410. Defaults to @samp{disabled}.
  18411. @end deftypevr
  18412. @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
  18413. Specifies the number of seconds to sleep when connecting to all LDAP
  18414. servers fails. By default one second is waited between the first
  18415. failure and the first retry.
  18416. Defaults to @samp{disabled}.
  18417. @end deftypevr
  18418. @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
  18419. Specifies the time after which the LDAP server is considered to be
  18420. permanently unavailable. Once this time is reached retries will be done
  18421. only once per this time period. The default value is 10 seconds.
  18422. Defaults to @samp{disabled}.
  18423. @end deftypevr
  18424. @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
  18425. Specifies whether to use SSL/TLS or not (the default is not to). If
  18426. 'start-tls is specified then StartTLS is used rather than raw LDAP over
  18427. SSL.
  18428. Defaults to @samp{disabled}.
  18429. @end deftypevr
  18430. @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
  18431. Specifies what checks to perform on a server-supplied certificate. The
  18432. meaning of the values is described in the ldap.conf(5) manual page.
  18433. Defaults to @samp{disabled}.
  18434. @end deftypevr
  18435. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
  18436. Specifies the directory containing X.509 certificates for peer authen‐
  18437. tication. This parameter is ignored when using GnuTLS.
  18438. Defaults to @samp{disabled}.
  18439. @end deftypevr
  18440. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
  18441. Specifies the path to the X.509 certificate for peer authentication.
  18442. Defaults to @samp{disabled}.
  18443. @end deftypevr
  18444. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
  18445. Specifies the path to an entropy source. This parameter is ignored when
  18446. using GnuTLS.
  18447. Defaults to @samp{disabled}.
  18448. @end deftypevr
  18449. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
  18450. Specifies the ciphers to use for TLS as a string.
  18451. Defaults to @samp{disabled}.
  18452. @end deftypevr
  18453. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
  18454. Specifies the path to the file containing the local certificate for
  18455. client TLS authentication.
  18456. Defaults to @samp{disabled}.
  18457. @end deftypevr
  18458. @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
  18459. Specifies the path to the file containing the private key for client TLS
  18460. authentication.
  18461. Defaults to @samp{disabled}.
  18462. @end deftypevr
  18463. @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
  18464. Set this to a number greater than 0 to request paged results from the
  18465. LDAP server in accordance with RFC2696. The default (0) is to not
  18466. request paged results.
  18467. Defaults to @samp{disabled}.
  18468. @end deftypevr
  18469. @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
  18470. This option prevents group membership lookups through LDAP for the
  18471. specified users. Alternatively, the value 'all-local may be used. With
  18472. that value nslcd builds a full list of non-LDAP users on startup.
  18473. Defaults to @samp{disabled}.
  18474. @end deftypevr
  18475. @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
  18476. This option ensures that LDAP users with a numeric user id lower than
  18477. the specified value are ignored.
  18478. Defaults to @samp{disabled}.
  18479. @end deftypevr
  18480. @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
  18481. This option specifies an offset that is added to all LDAP numeric user
  18482. ids. This can be used to avoid user id collisions with local users.
  18483. Defaults to @samp{disabled}.
  18484. @end deftypevr
  18485. @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
  18486. This option specifies an offset that is added to all LDAP numeric group
  18487. ids. This can be used to avoid user id collisions with local groups.
  18488. Defaults to @samp{disabled}.
  18489. @end deftypevr
  18490. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
  18491. If this option is set, the member attribute of a group may point to
  18492. another group. Members of nested groups are also returned in the higher
  18493. level group and parent groups are returned when finding groups for a
  18494. specific user. The default is not to perform extra searches for nested
  18495. groups.
  18496. Defaults to @samp{disabled}.
  18497. @end deftypevr
  18498. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
  18499. If this option is set, the group member list is not retrieved when
  18500. looking up groups. Lookups for finding which groups a user belongs to
  18501. will remain functional so the user will likely still get the correct
  18502. groups assigned on login.
  18503. Defaults to @samp{disabled}.
  18504. @end deftypevr
  18505. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
  18506. If this option is set, functions which cause all user/group entries to
  18507. be loaded from the directory will not succeed in doing so. This can
  18508. dramatically reduce LDAP server load in situations where there are a
  18509. great number of users and/or groups. This option is not recommended for
  18510. most configurations.
  18511. Defaults to @samp{disabled}.
  18512. @end deftypevr
  18513. @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
  18514. This option can be used to specify how user and group names are verified
  18515. within the system. This pattern is used to check all user and group
  18516. names that are requested and returned from LDAP.
  18517. Defaults to @samp{disabled}.
  18518. @end deftypevr
  18519. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
  18520. This specifies whether or not to perform searches using case-insensitive
  18521. matching. Enabling this could open up the system to authorization
  18522. bypass vulnerabilities and introduce nscd cache poisoning
  18523. vulnerabilities which allow denial of service.
  18524. Defaults to @samp{disabled}.
  18525. @end deftypevr
  18526. @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
  18527. This option specifies whether password policy controls are requested and
  18528. handled from the LDAP server when performing user authentication.
  18529. Defaults to @samp{disabled}.
  18530. @end deftypevr
  18531. @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
  18532. By default nslcd performs an LDAP search with the user's credentials
  18533. after BIND (authentication) to ensure that the BIND operation was
  18534. successful. The default search is a simple check to see if the user's
  18535. DN exists. A search filter can be specified that will be used instead.
  18536. It should return at least one entry.
  18537. Defaults to @samp{disabled}.
  18538. @end deftypevr
  18539. @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
  18540. This option allows flexible fine tuning of the authorisation check that
  18541. should be performed. The search filter specified is executed and if any
  18542. entries match, access is granted, otherwise access is denied.
  18543. Defaults to @samp{disabled}.
  18544. @end deftypevr
  18545. @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
  18546. If this option is set password modification using pam_ldap will be
  18547. denied and the specified message will be presented to the user instead.
  18548. The message can be used to direct the user to an alternative means of
  18549. changing their password.
  18550. Defaults to @samp{disabled}.
  18551. @end deftypevr
  18552. @deftypevr {@code{nslcd-configuration} parameter} list pam-services
  18553. List of pam service names for which LDAP authentication should suffice.
  18554. Defaults to @samp{()}.
  18555. @end deftypevr
  18556. @c %end of generated documentation for nslcd-configuration
  18557. @node Web Services
  18558. @subsection Web Services
  18559. @cindex web
  18560. @cindex www
  18561. @cindex HTTP
  18562. The @code{(gnu services web)} module provides the Apache HTTP Server,
  18563. the nginx web server, and also a fastcgi wrapper daemon.
  18564. @subsubheading Apache HTTP Server
  18565. @deffn {Scheme Variable} httpd-service-type
  18566. Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
  18567. (@dfn{httpd}). The value for this service type is a
  18568. @code{httpd-configuration} record.
  18569. A simple example configuration is given below.
  18570. @lisp
  18571. (service httpd-service-type
  18572. (httpd-configuration
  18573. (config
  18574. (httpd-config-file
  18575. (server-name "www.example.com")
  18576. (document-root "/srv/http/www.example.com")))))
  18577. @end lisp
  18578. Other services can also extend the @code{httpd-service-type} to add to
  18579. the configuration.
  18580. @lisp
  18581. (simple-service 'www.example.com-server httpd-service-type
  18582. (list
  18583. (httpd-virtualhost
  18584. "*:80"
  18585. (list (string-join '("ServerName www.example.com"
  18586. "DocumentRoot /srv/http/www.example.com")
  18587. "\n")))))
  18588. @end lisp
  18589. @end deffn
  18590. The details for the @code{httpd-configuration}, @code{httpd-module},
  18591. @code{httpd-config-file} and @code{httpd-virtualhost} record types are
  18592. given below.
  18593. @deffn {Data Type} httpd-configuration
  18594. This data type represents the configuration for the httpd service.
  18595. @table @asis
  18596. @item @code{package} (default: @code{httpd})
  18597. The httpd package to use.
  18598. @item @code{pid-file} (default: @code{"/var/run/httpd"})
  18599. The pid file used by the shepherd-service.
  18600. @item @code{config} (default: @code{(httpd-config-file)})
  18601. The configuration file to use with the httpd service. The default value
  18602. is a @code{httpd-config-file} record, but this can also be a different
  18603. G-expression that generates a file, for example a @code{plain-file}. A
  18604. file outside of the store can also be specified through a string.
  18605. @end table
  18606. @end deffn
  18607. @deffn {Data Type} httpd-module
  18608. This data type represents a module for the httpd service.
  18609. @table @asis
  18610. @item @code{name}
  18611. The name of the module.
  18612. @item @code{file}
  18613. The file for the module. This can be relative to the httpd package being
  18614. used, the absolute location of a file, or a G-expression for a file
  18615. within the store, for example @code{(file-append mod-wsgi
  18616. "/modules/mod_wsgi.so")}.
  18617. @end table
  18618. @end deffn
  18619. @defvr {Scheme Variable} %default-httpd-modules
  18620. A default list of @code{httpd-module} objects.
  18621. @end defvr
  18622. @deffn {Data Type} httpd-config-file
  18623. This data type represents a configuration file for the httpd service.
  18624. @table @asis
  18625. @item @code{modules} (default: @code{%default-httpd-modules})
  18626. The modules to load. Additional modules can be added here, or loaded by
  18627. additional configuration.
  18628. For example, in order to handle requests for PHP files, you can use Apache’s
  18629. @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
  18630. @lisp
  18631. (service httpd-service-type
  18632. (httpd-configuration
  18633. (config
  18634. (httpd-config-file
  18635. (modules (cons*
  18636. (httpd-module
  18637. (name "proxy_module")
  18638. (file "modules/mod_proxy.so"))
  18639. (httpd-module
  18640. (name "proxy_fcgi_module")
  18641. (file "modules/mod_proxy_fcgi.so"))
  18642. %default-httpd-modules))
  18643. (extra-config (list "\
  18644. <FilesMatch \\.php$>
  18645. SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
  18646. </FilesMatch>"))))))
  18647. (service php-fpm-service-type
  18648. (php-fpm-configuration
  18649. (socket "/var/run/php-fpm.sock")
  18650. (socket-group "httpd")))
  18651. @end lisp
  18652. @item @code{server-root} (default: @code{httpd})
  18653. The @code{ServerRoot} in the configuration file, defaults to the httpd
  18654. package. Directives including @code{Include} and @code{LoadModule} are
  18655. taken as relative to the server root.
  18656. @item @code{server-name} (default: @code{#f})
  18657. The @code{ServerName} in the configuration file, used to specify the
  18658. request scheme, hostname and port that the server uses to identify
  18659. itself.
  18660. This doesn't need to be set in the server config, and can be specified
  18661. in virtual hosts. The default is @code{#f} to not specify a
  18662. @code{ServerName}.
  18663. @item @code{document-root} (default: @code{"/srv/http"})
  18664. The @code{DocumentRoot} from which files will be served.
  18665. @item @code{listen} (default: @code{'("80")})
  18666. The list of values for the @code{Listen} directives in the config
  18667. file. The value should be a list of strings, when each string can
  18668. specify the port number to listen on, and optionally the IP address and
  18669. protocol to use.
  18670. @item @code{pid-file} (default: @code{"/var/run/httpd"})
  18671. The @code{PidFile} to use. This should match the @code{pid-file} set in
  18672. the @code{httpd-configuration} so that the Shepherd service is
  18673. configured correctly.
  18674. @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
  18675. The @code{ErrorLog} to which the server will log errors.
  18676. @item @code{user} (default: @code{"httpd"})
  18677. The @code{User} which the server will answer requests as.
  18678. @item @code{group} (default: @code{"httpd"})
  18679. The @code{Group} which the server will answer requests as.
  18680. @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
  18681. A flat list of strings and G-expressions which will be added to the end
  18682. of the configuration file.
  18683. Any values which the service is extended with will be appended to this
  18684. list.
  18685. @end table
  18686. @end deffn
  18687. @deffn {Data Type} httpd-virtualhost
  18688. This data type represents a virtualhost configuration block for the httpd service.
  18689. These should be added to the extra-config for the httpd-service.
  18690. @lisp
  18691. (simple-service 'www.example.com-server httpd-service-type
  18692. (list
  18693. (httpd-virtualhost
  18694. "*:80"
  18695. (list (string-join '("ServerName www.example.com"
  18696. "DocumentRoot /srv/http/www.example.com")
  18697. "\n")))))
  18698. @end lisp
  18699. @table @asis
  18700. @item @code{addresses-and-ports}
  18701. The addresses and ports for the @code{VirtualHost} directive.
  18702. @item @code{contents}
  18703. The contents of the @code{VirtualHost} directive, this should be a list
  18704. of strings and G-expressions.
  18705. @end table
  18706. @end deffn
  18707. @subsubheading NGINX
  18708. @deffn {Scheme Variable} nginx-service-type
  18709. Service type for the @uref{https://nginx.org/,NGinx} web server. The
  18710. value for this service type is a @code{<nginx-configuration>} record.
  18711. A simple example configuration is given below.
  18712. @lisp
  18713. (service nginx-service-type
  18714. (nginx-configuration
  18715. (server-blocks
  18716. (list (nginx-server-configuration
  18717. (server-name '("www.example.com"))
  18718. (root "/srv/http/www.example.com"))))))
  18719. @end lisp
  18720. In addition to adding server blocks to the service configuration
  18721. directly, this service can be extended by other services to add server
  18722. blocks, as in this example:
  18723. @lisp
  18724. (simple-service 'my-extra-server nginx-service-type
  18725. (list (nginx-server-configuration
  18726. (root "/srv/http/extra-website")
  18727. (try-files (list "$uri" "$uri/index.html")))))
  18728. @end lisp
  18729. @end deffn
  18730. At startup, @command{nginx} has not yet read its configuration file, so
  18731. it uses a default file to log error messages. If it fails to load its
  18732. configuration file, that is where error messages are logged. After the
  18733. configuration file is loaded, the default error log file changes as per
  18734. configuration. In our case, startup error messages can be found in
  18735. @file{/var/run/nginx/logs/error.log}, and after configuration in
  18736. @file{/var/log/nginx/error.log}. The second location can be changed
  18737. with the @var{log-directory} configuration option.
  18738. @deffn {Data Type} nginx-configuration
  18739. This data type represents the configuration for NGinx. Some
  18740. configuration can be done through this and the other provided record
  18741. types, or alternatively, a config file can be provided.
  18742. @table @asis
  18743. @item @code{nginx} (default: @code{nginx})
  18744. The nginx package to use.
  18745. @item @code{log-directory} (default: @code{"/var/log/nginx"})
  18746. The directory to which NGinx will write log files.
  18747. @item @code{run-directory} (default: @code{"/var/run/nginx"})
  18748. The directory in which NGinx will create a pid file, and write temporary
  18749. files.
  18750. @item @code{server-blocks} (default: @code{'()})
  18751. A list of @dfn{server blocks} to create in the generated configuration
  18752. file, the elements should be of type
  18753. @code{<nginx-server-configuration>}.
  18754. The following example would setup NGinx to serve @code{www.example.com}
  18755. from the @code{/srv/http/www.example.com} directory, without using
  18756. HTTPS.
  18757. @lisp
  18758. (service nginx-service-type
  18759. (nginx-configuration
  18760. (server-blocks
  18761. (list (nginx-server-configuration
  18762. (server-name '("www.example.com"))
  18763. (root "/srv/http/www.example.com"))))))
  18764. @end lisp
  18765. @item @code{upstream-blocks} (default: @code{'()})
  18766. A list of @dfn{upstream blocks} to create in the generated configuration
  18767. file, the elements should be of type
  18768. @code{<nginx-upstream-configuration>}.
  18769. Configuring upstreams through the @code{upstream-blocks} can be useful
  18770. when combined with @code{locations} in the
  18771. @code{<nginx-server-configuration>} records. The following example
  18772. creates a server configuration with one location configuration, that
  18773. will proxy requests to a upstream configuration, which will handle
  18774. requests with two servers.
  18775. @lisp
  18776. (service
  18777. nginx-service-type
  18778. (nginx-configuration
  18779. (server-blocks
  18780. (list (nginx-server-configuration
  18781. (server-name '("www.example.com"))
  18782. (root "/srv/http/www.example.com")
  18783. (locations
  18784. (list
  18785. (nginx-location-configuration
  18786. (uri "/path1")
  18787. (body '("proxy_pass http://server-proxy;"))))))))
  18788. (upstream-blocks
  18789. (list (nginx-upstream-configuration
  18790. (name "server-proxy")
  18791. (servers (list "server1.example.com"
  18792. "server2.example.com")))))))
  18793. @end lisp
  18794. @item @code{file} (default: @code{#f})
  18795. If a configuration @var{file} is provided, this will be used, rather than
  18796. generating a configuration file from the provided @code{log-directory},
  18797. @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
  18798. proper operation, these arguments should match what is in @var{file} to ensure
  18799. that the directories are created when the service is activated.
  18800. This can be useful if you have an existing configuration file, or it's
  18801. not possible to do what is required through the other parts of the
  18802. nginx-configuration record.
  18803. @item @code{server-names-hash-bucket-size} (default: @code{#f})
  18804. Bucket size for the server names hash tables, defaults to @code{#f} to
  18805. use the size of the processors cache line.
  18806. @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
  18807. Maximum bucket size for the server names hash tables.
  18808. @item @code{modules} (default: @code{'()})
  18809. List of nginx dynamic modules to load. This should be a list of file
  18810. names of loadable modules, as in this example:
  18811. @lisp
  18812. (modules
  18813. (list
  18814. (file-append nginx-accept-language-module "\
  18815. /etc/nginx/modules/ngx_http_accept_language_module.so")
  18816. (file-append nginx-lua-module "\
  18817. /etc/nginx/modules/ngx_http_lua_module.so")))
  18818. @end lisp
  18819. @item @code{lua-package-path} (default: @code{'()})
  18820. List of nginx lua packages to load. This should be a list of package
  18821. names of loadable lua modules, as in this example:
  18822. @lisp
  18823. (lua-package-path (list lua-resty-core
  18824. lua-resty-lrucache
  18825. lua-resty-signal
  18826. lua-tablepool
  18827. lua-resty-shell))
  18828. @end lisp
  18829. @item @code{lua-package-cpath} (default: @code{'()})
  18830. List of nginx lua C packages to load. This should be a list of package
  18831. names of loadable lua C modules, as in this example:
  18832. @lisp
  18833. (lua-package-cpath (list lua-resty-signal))
  18834. @end lisp
  18835. @item @code{global-directives} (default: @code{'((events . ()))})
  18836. Association list of global directives for the top level of the nginx
  18837. configuration. Values may themselves be association lists.
  18838. @lisp
  18839. (global-directives
  18840. `((worker_processes . 16)
  18841. (pcre_jit . on)
  18842. (events . ((worker_connections . 1024)))))
  18843. @end lisp
  18844. @item @code{extra-content} (default: @code{""})
  18845. Extra content for the @code{http} block. Should be string or a string
  18846. valued G-expression.
  18847. @end table
  18848. @end deffn
  18849. @deftp {Data Type} nginx-server-configuration
  18850. Data type representing the configuration of an nginx server block.
  18851. This type has the following parameters:
  18852. @table @asis
  18853. @item @code{listen} (default: @code{'("80" "443 ssl")})
  18854. Each @code{listen} directive sets the address and port for IP, or the
  18855. path for a UNIX-domain socket on which the server will accept requests.
  18856. Both address and port, or only address or only port can be specified.
  18857. An address may also be a hostname, for example:
  18858. @lisp
  18859. '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
  18860. @end lisp
  18861. @item @code{server-name} (default: @code{(list 'default)})
  18862. A list of server names this server represents. @code{'default} represents the
  18863. default server for connections matching no other server.
  18864. @item @code{root} (default: @code{"/srv/http"})
  18865. Root of the website nginx will serve.
  18866. @item @code{locations} (default: @code{'()})
  18867. A list of @dfn{nginx-location-configuration} or
  18868. @dfn{nginx-named-location-configuration} records to use within this
  18869. server block.
  18870. @item @code{index} (default: @code{(list "index.html")})
  18871. Index files to look for when clients ask for a directory. If it cannot be found,
  18872. Nginx will send the list of files in the directory.
  18873. @item @code{try-files} (default: @code{'()})
  18874. A list of files whose existence is checked in the specified order.
  18875. @code{nginx} will use the first file it finds to process the request.
  18876. @item @code{ssl-certificate} (default: @code{#f})
  18877. Where to find the certificate for secure connections. Set it to @code{#f} if
  18878. you don't have a certificate or you don't want to use HTTPS.
  18879. @item @code{ssl-certificate-key} (default: @code{#f})
  18880. Where to find the private key for secure connections. Set it to @code{#f} if
  18881. you don't have a key or you don't want to use HTTPS.
  18882. @item @code{server-tokens?} (default: @code{#f})
  18883. Whether the server should add its configuration to response.
  18884. @item @code{raw-content} (default: @code{'()})
  18885. A list of raw lines added to the server block.
  18886. @end table
  18887. @end deftp
  18888. @deftp {Data Type} nginx-upstream-configuration
  18889. Data type representing the configuration of an nginx @code{upstream}
  18890. block. This type has the following parameters:
  18891. @table @asis
  18892. @item @code{name}
  18893. Name for this group of servers.
  18894. @item @code{servers}
  18895. Specify the addresses of the servers in the group. The address can be
  18896. specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
  18897. (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
  18898. prefix @samp{unix:}. For addresses using an IP address or domain name,
  18899. the default port is 80, and a different port can be specified
  18900. explicitly.
  18901. @end table
  18902. @end deftp
  18903. @deftp {Data Type} nginx-location-configuration
  18904. Data type representing the configuration of an nginx @code{location}
  18905. block. This type has the following parameters:
  18906. @table @asis
  18907. @item @code{uri}
  18908. URI which this location block matches.
  18909. @anchor{nginx-location-configuration body}
  18910. @item @code{body}
  18911. Body of the location block, specified as a list of strings. This can contain
  18912. many
  18913. configuration directives. For example, to pass requests to a upstream
  18914. server group defined using an @code{nginx-upstream-configuration} block,
  18915. the following directive would be specified in the body @samp{(list "proxy_pass
  18916. http://upstream-name;")}.
  18917. @end table
  18918. @end deftp
  18919. @deftp {Data Type} nginx-named-location-configuration
  18920. Data type representing the configuration of an nginx named location
  18921. block. Named location blocks are used for request redirection, and not
  18922. used for regular request processing. This type has the following
  18923. parameters:
  18924. @table @asis
  18925. @item @code{name}
  18926. Name to identify this location block.
  18927. @item @code{body}
  18928. @xref{nginx-location-configuration body}, as the body for named location
  18929. blocks can be used in a similar way to the
  18930. @code{nginx-location-configuration body}. One restriction is that the
  18931. body of a named location block cannot contain location blocks.
  18932. @end table
  18933. @end deftp
  18934. @subsubheading Varnish Cache
  18935. @cindex Varnish
  18936. Varnish is a fast cache server that sits in between web applications
  18937. and end users. It proxies requests from clients and caches the
  18938. accessed URLs such that multiple requests for the same resource only
  18939. creates one request to the back-end.
  18940. @defvr {Scheme Variable} varnish-service-type
  18941. Service type for the Varnish daemon.
  18942. @end defvr
  18943. @deftp {Data Type} varnish-configuration
  18944. Data type representing the @code{varnish} service configuration.
  18945. This type has the following parameters:
  18946. @table @asis
  18947. @item @code{package} (default: @code{varnish})
  18948. The Varnish package to use.
  18949. @item @code{name} (default: @code{"default"})
  18950. A name for this Varnish instance. Varnish will create a directory in
  18951. @file{/var/varnish/} with this name and keep temporary files there. If
  18952. the name starts with a forward slash, it is interpreted as an absolute
  18953. directory name.
  18954. Pass the @code{-n} argument to other Varnish programs to connect to the
  18955. named instance, e.g.@: @command{varnishncsa -n default}.
  18956. @item @code{backend} (default: @code{"localhost:8080"})
  18957. The backend to use. This option has no effect if @code{vcl} is set.
  18958. @item @code{vcl} (default: #f)
  18959. The @dfn{VCL} (Varnish Configuration Language) program to run. If this
  18960. is @code{#f}, Varnish will proxy @code{backend} using the default
  18961. configuration. Otherwise this must be a file-like object with valid
  18962. VCL syntax.
  18963. @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
  18964. For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
  18965. can do something along these lines:
  18966. @lisp
  18967. (define %gnu-mirror
  18968. (plain-file "gnu.vcl"
  18969. "vcl 4.1;
  18970. backend gnu @{ .host = \"www.gnu.org\"; @}"))
  18971. (operating-system
  18972. ;; @dots{}
  18973. (services (cons (service varnish-service-type
  18974. (varnish-configuration
  18975. (listen '(":80"))
  18976. (vcl %gnu-mirror)))
  18977. %base-services)))
  18978. @end lisp
  18979. The configuration of an already running Varnish instance can be inspected
  18980. and changed using the @command{varnishadm} program.
  18981. Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
  18982. @url{https://book.varnish-software.com/4.0/,Varnish Book} for
  18983. comprehensive documentation on Varnish and its configuration language.
  18984. @item @code{listen} (default: @code{'("localhost:80")})
  18985. List of addresses Varnish will listen on.
  18986. @item @code{storage} (default: @code{'("malloc,128m")})
  18987. List of storage backends that will be available in VCL.
  18988. @item @code{parameters} (default: @code{'()})
  18989. List of run-time parameters in the form @code{'(("parameter" . "value"))}.
  18990. @item @code{extra-options} (default: @code{'()})
  18991. Additional arguments to pass to the @command{varnishd} process.
  18992. @end table
  18993. @end deftp
  18994. @subsubheading Patchwork
  18995. @cindex Patchwork
  18996. Patchwork is a patch tracking system. It can collect patches sent to a
  18997. mailing list, and display them in a web interface.
  18998. @defvr {Scheme Variable} patchwork-service-type
  18999. Service type for Patchwork.
  19000. @end defvr
  19001. The following example is an example of a minimal service for Patchwork, for
  19002. the @code{patchwork.example.com} domain.
  19003. @lisp
  19004. (service patchwork-service-type
  19005. (patchwork-configuration
  19006. (domain "patchwork.example.com")
  19007. (settings-module
  19008. (patchwork-settings-module
  19009. (allowed-hosts (list domain))
  19010. (default-from-email "patchwork@@patchwork.example.com")))
  19011. (getmail-retriever-config
  19012. (getmail-retriever-configuration
  19013. (type "SimpleIMAPSSLRetriever")
  19014. (server "imap.example.com")
  19015. (port 993)
  19016. (username "patchwork")
  19017. (password-command
  19018. (list (file-append coreutils "/bin/cat")
  19019. "/etc/getmail-patchwork-imap-password"))
  19020. (extra-parameters
  19021. '((mailboxes . ("Patches"))))))))
  19022. @end lisp
  19023. There are three records for configuring the Patchwork service. The
  19024. @code{<patchwork-configuration>} relates to the configuration for Patchwork
  19025. within the HTTPD service.
  19026. The @code{settings-module} field within the @code{<patchwork-configuration>}
  19027. record can be populated with the @code{<patchwork-settings-module>} record,
  19028. which describes a settings module that is generated within the Guix store.
  19029. For the @code{database-configuration} field within the
  19030. @code{<patchwork-settings-module>}, the
  19031. @code{<patchwork-database-configuration>} must be used.
  19032. @deftp {Data Type} patchwork-configuration
  19033. Data type representing the Patchwork service configuration. This type has the
  19034. following parameters:
  19035. @table @asis
  19036. @item @code{patchwork} (default: @code{patchwork})
  19037. The Patchwork package to use.
  19038. @item @code{domain}
  19039. The domain to use for Patchwork, this is used in the HTTPD service virtual
  19040. host.
  19041. @item @code{settings-module}
  19042. The settings module to use for Patchwork. As a Django application, Patchwork
  19043. is configured with a Python module containing the settings. This can either be
  19044. an instance of the @code{<patchwork-settings-module>} record, any other record
  19045. that represents the settings in the store, or a directory outside of the
  19046. store.
  19047. @item @code{static-path} (default: @code{"/static/"})
  19048. The path under which the HTTPD service should serve the static files.
  19049. @item @code{getmail-retriever-config}
  19050. The getmail-retriever-configuration record value to use with
  19051. Patchwork. Getmail will be configured with this value, the messages will be
  19052. delivered to Patchwork.
  19053. @end table
  19054. @end deftp
  19055. @deftp {Data Type} patchwork-settings-module
  19056. Data type representing a settings module for Patchwork. Some of these
  19057. settings relate directly to Patchwork, but others relate to Django, the web
  19058. framework used by Patchwork, or the Django Rest Framework library. This type
  19059. has the following parameters:
  19060. @table @asis
  19061. @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
  19062. The database connection settings used for Patchwork. See the
  19063. @code{<patchwork-database-configuration>} record type for more information.
  19064. @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
  19065. Patchwork, as a Django web application uses a secret key for cryptographically
  19066. signing values. This file should contain a unique unpredictable value.
  19067. If this file does not exist, it will be created and populated with a random
  19068. value by the patchwork-setup shepherd service.
  19069. This setting relates to Django.
  19070. @item @code{allowed-hosts}
  19071. A list of valid hosts for this Patchwork service. This should at least include
  19072. the domain specified in the @code{<patchwork-configuration>} record.
  19073. This is a Django setting.
  19074. @item @code{default-from-email}
  19075. The email address from which Patchwork should send email by default.
  19076. This is a Patchwork setting.
  19077. @item @code{static-url} (default: @code{#f})
  19078. The URL to use when serving static assets. It can be part of a URL, or a full
  19079. URL, but must end in a @code{/}.
  19080. If the default value is used, the @code{static-path} value from the
  19081. @code{<patchwork-configuration>} record will be used.
  19082. This is a Django setting.
  19083. @item @code{admins} (default: @code{'()})
  19084. Email addresses to send the details of errors that occur. Each value should
  19085. be a list containing two elements, the name and then the email address.
  19086. This is a Django setting.
  19087. @item @code{debug?} (default: @code{#f})
  19088. Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
  19089. messages will be shown.
  19090. This is a Django setting.
  19091. @item @code{enable-rest-api?} (default: @code{#t})
  19092. Whether to enable the Patchwork REST API.
  19093. This is a Patchwork setting.
  19094. @item @code{enable-xmlrpc?} (default: @code{#t})
  19095. Whether to enable the XML RPC API.
  19096. This is a Patchwork setting.
  19097. @item @code{force-https-links?} (default: @code{#t})
  19098. Whether to use HTTPS links on Patchwork pages.
  19099. This is a Patchwork setting.
  19100. @item @code{extra-settings} (default: @code{""})
  19101. Extra code to place at the end of the Patchwork settings module.
  19102. @end table
  19103. @end deftp
  19104. @deftp {Data Type} patchwork-database-configuration
  19105. Data type representing the database configuration for Patchwork.
  19106. @table @asis
  19107. @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
  19108. The database engine to use.
  19109. @item @code{name} (default: @code{"patchwork"})
  19110. The name of the database to use.
  19111. @item @code{user} (default: @code{"httpd"})
  19112. The user to connect to the database as.
  19113. @item @code{password} (default: @code{""})
  19114. The password to use when connecting to the database.
  19115. @item @code{host} (default: @code{""})
  19116. The host to make the database connection to.
  19117. @item @code{port} (default: @code{""})
  19118. The port on which to connect to the database.
  19119. @end table
  19120. @end deftp
  19121. @subsubheading Mumi
  19122. @cindex Mumi, Debbugs Web interface
  19123. @cindex Debbugs, Mumi Web interface
  19124. @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
  19125. Web interface to the Debbugs bug tracker, by default for
  19126. @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
  19127. but it also fetches and indexes mail retrieved from Debbugs.
  19128. @defvr {Scheme Variable} mumi-service-type
  19129. This is the service type for Mumi.
  19130. @end defvr
  19131. @deftp {Data Type} mumi-configuration
  19132. Data type representing the Mumi service configuration. This type has the
  19133. following fields:
  19134. @table @asis
  19135. @item @code{mumi} (default: @code{mumi})
  19136. The Mumi package to use.
  19137. @item @code{mailer?} (default: @code{#true})
  19138. Whether to enable or disable the mailer component.
  19139. @item @code{mumi-configuration-sender}
  19140. The email address used as the sender for comments.
  19141. @item @code{mumi-configuration-smtp}
  19142. A URI to configure the SMTP settings for Mailutils. This could be
  19143. something like @code{sendmail:///path/to/bin/msmtp} or any other URI
  19144. supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
  19145. mailutils, GNU@tie{}Mailutils}.
  19146. @end table
  19147. @end deftp
  19148. @subsubheading FastCGI
  19149. @cindex fastcgi
  19150. @cindex fcgiwrap
  19151. FastCGI is an interface between the front-end and the back-end of a web
  19152. service. It is a somewhat legacy facility; new web services should
  19153. generally just talk HTTP between the front-end and the back-end.
  19154. However there are a number of back-end services such as PHP or the
  19155. optimized HTTP Git repository access that use FastCGI, so we have
  19156. support for it in Guix.
  19157. To use FastCGI, you configure the front-end web server (e.g., nginx) to
  19158. dispatch some subset of its requests to the fastcgi backend, which
  19159. listens on a local TCP or UNIX socket. There is an intermediary
  19160. @code{fcgiwrap} program that sits between the actual backend process and
  19161. the web server. The front-end indicates which backend program to run,
  19162. passing that information to the @code{fcgiwrap} process.
  19163. @defvr {Scheme Variable} fcgiwrap-service-type
  19164. A service type for the @code{fcgiwrap} FastCGI proxy.
  19165. @end defvr
  19166. @deftp {Data Type} fcgiwrap-configuration
  19167. Data type representing the configuration of the @code{fcgiwrap} service.
  19168. This type has the following parameters:
  19169. @table @asis
  19170. @item @code{package} (default: @code{fcgiwrap})
  19171. The fcgiwrap package to use.
  19172. @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
  19173. The socket on which the @code{fcgiwrap} process should listen, as a
  19174. string. Valid @var{socket} values include
  19175. @code{unix:@var{/path/to/unix/socket}},
  19176. @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
  19177. @code{tcp6:[@var{ipv6_addr}]:port}.
  19178. @item @code{user} (default: @code{fcgiwrap})
  19179. @itemx @code{group} (default: @code{fcgiwrap})
  19180. The user and group names, as strings, under which to run the
  19181. @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
  19182. the user asks for the specific user or group names @code{fcgiwrap} that
  19183. the corresponding user and/or group is present on the system.
  19184. It is possible to configure a FastCGI-backed web service to pass HTTP
  19185. authentication information from the front-end to the back-end, and to
  19186. allow @code{fcgiwrap} to run the back-end process as a corresponding
  19187. local user. To enable this capability on the back-end, run
  19188. @code{fcgiwrap} as the @code{root} user and group. Note that this
  19189. capability also has to be configured on the front-end as well.
  19190. @end table
  19191. @end deftp
  19192. @cindex php-fpm
  19193. PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
  19194. with some additional features useful for sites of any size.
  19195. These features include:
  19196. @itemize @bullet
  19197. @item Adaptive process spawning
  19198. @item Basic statistics (similar to Apache's mod_status)
  19199. @item Advanced process management with graceful stop/start
  19200. @item Ability to start workers with different uid/gid/chroot/environment
  19201. and different php.ini (replaces safe_mode)
  19202. @item Stdout & stderr logging
  19203. @item Emergency restart in case of accidental opcode cache destruction
  19204. @item Accelerated upload support
  19205. @item Support for a "slowlog"
  19206. @item Enhancements to FastCGI, such as fastcgi_finish_request() -
  19207. a special function to finish request & flush all data while continuing to do
  19208. something time-consuming (video converting, stats processing, etc.)
  19209. @end itemize
  19210. ...@: and much more.
  19211. @defvr {Scheme Variable} php-fpm-service-type
  19212. A Service type for @code{php-fpm}.
  19213. @end defvr
  19214. @deftp {Data Type} php-fpm-configuration
  19215. Data Type for php-fpm service configuration.
  19216. @table @asis
  19217. @item @code{php} (default: @code{php})
  19218. The php package to use.
  19219. @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
  19220. The address on which to accept FastCGI requests. Valid syntaxes are:
  19221. @table @asis
  19222. @item @code{"ip.add.re.ss:port"}
  19223. Listen on a TCP socket to a specific address on a specific port.
  19224. @item @code{"port"}
  19225. Listen on a TCP socket to all addresses on a specific port.
  19226. @item @code{"/path/to/unix/socket"}
  19227. Listen on a unix socket.
  19228. @end table
  19229. @item @code{user} (default: @code{php-fpm})
  19230. User who will own the php worker processes.
  19231. @item @code{group} (default: @code{php-fpm})
  19232. Group of the worker processes.
  19233. @item @code{socket-user} (default: @code{php-fpm})
  19234. User who can speak to the php-fpm socket.
  19235. @item @code{socket-group} (default: @code{nginx})
  19236. Group that can speak to the php-fpm socket.
  19237. @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
  19238. The process id of the php-fpm process is written to this file
  19239. once the service has started.
  19240. @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
  19241. Log for the php-fpm master process.
  19242. @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
  19243. Detailed settings for the php-fpm process manager.
  19244. Must be one of:
  19245. @table @asis
  19246. @item @code{<php-fpm-dynamic-process-manager-configuration>}
  19247. @item @code{<php-fpm-static-process-manager-configuration>}
  19248. @item @code{<php-fpm-on-demand-process-manager-configuration>}
  19249. @end table
  19250. @item @code{display-errors} (default @code{#f})
  19251. Determines whether php errors and warning should be sent to clients
  19252. and displayed in their browsers.
  19253. This is useful for local php development, but a security risk for public sites,
  19254. as error messages can reveal passwords and personal data.
  19255. @item @code{timezone} (default @code{#f})
  19256. Specifies @code{php_admin_value[date.timezone]} parameter.
  19257. @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
  19258. This file will log the @code{stderr} outputs of php worker processes.
  19259. Can be set to @code{#f} to disable logging.
  19260. @item @code{file} (default @code{#f})
  19261. An optional override of the whole configuration.
  19262. You can use the @code{mixed-text-file} function or an absolute filepath for it.
  19263. @item @code{php-ini-file} (default @code{#f})
  19264. An optional override of the default php settings.
  19265. It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
  19266. You can use the @code{mixed-text-file} function or an absolute filepath for it.
  19267. For local development it is useful to set a higher timeout and memory
  19268. limit for spawned php processes. This be accomplished with the
  19269. following operating system configuration snippet:
  19270. @lisp
  19271. (define %local-php-ini
  19272. (plain-file "php.ini"
  19273. "memory_limit = 2G
  19274. max_execution_time = 1800"))
  19275. (operating-system
  19276. ;; @dots{}
  19277. (services (cons (service php-fpm-service-type
  19278. (php-fpm-configuration
  19279. (php-ini-file %local-php-ini)))
  19280. %base-services)))
  19281. @end lisp
  19282. Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
  19283. directives} for comprehensive documentation on the acceptable
  19284. @file{php.ini} directives.
  19285. @end table
  19286. @end deftp
  19287. @deftp {Data type} php-fpm-dynamic-process-manager-configuration
  19288. Data Type for the @code{dynamic} php-fpm process manager. With the
  19289. @code{dynamic} process manager, spare worker processes are kept around
  19290. based on it's configured limits.
  19291. @table @asis
  19292. @item @code{max-children} (default: @code{5})
  19293. Maximum of worker processes.
  19294. @item @code{start-servers} (default: @code{2})
  19295. How many worker processes should be started on start-up.
  19296. @item @code{min-spare-servers} (default: @code{1})
  19297. How many spare worker processes should be kept around at minimum.
  19298. @item @code{max-spare-servers} (default: @code{3})
  19299. How many spare worker processes should be kept around at maximum.
  19300. @end table
  19301. @end deftp
  19302. @deftp {Data type} php-fpm-static-process-manager-configuration
  19303. Data Type for the @code{static} php-fpm process manager. With the
  19304. @code{static} process manager, an unchanging number of worker processes
  19305. are created.
  19306. @table @asis
  19307. @item @code{max-children} (default: @code{5})
  19308. Maximum of worker processes.
  19309. @end table
  19310. @end deftp
  19311. @deftp {Data type} php-fpm-on-demand-process-manager-configuration
  19312. Data Type for the @code{on-demand} php-fpm process manager. With the
  19313. @code{on-demand} process manager, worker processes are only created as
  19314. requests arrive.
  19315. @table @asis
  19316. @item @code{max-children} (default: @code{5})
  19317. Maximum of worker processes.
  19318. @item @code{process-idle-timeout} (default: @code{10})
  19319. The time in seconds after which a process with no requests is killed.
  19320. @end table
  19321. @end deftp
  19322. @deffn {Scheme Procedure} nginx-php-location @
  19323. [#:nginx-package nginx] @
  19324. [socket (string-append "/var/run/php" @
  19325. (version-major (package-version php)) @
  19326. "-fpm.sock")]
  19327. A helper function to quickly add php to an @code{nginx-server-configuration}.
  19328. @end deffn
  19329. A simple services setup for nginx with php can look like this:
  19330. @lisp
  19331. (services (cons* (service dhcp-client-service-type)
  19332. (service php-fpm-service-type)
  19333. (service nginx-service-type
  19334. (nginx-server-configuration
  19335. (server-name '("example.com"))
  19336. (root "/srv/http/")
  19337. (locations
  19338. (list (nginx-php-location)))
  19339. (listen '("80"))
  19340. (ssl-certificate #f)
  19341. (ssl-certificate-key #f)))
  19342. %base-services))
  19343. @end lisp
  19344. @cindex cat-avatar-generator
  19345. The cat avatar generator is a simple service to demonstrate the use of php-fpm
  19346. in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
  19347. the hash of a user's email address.
  19348. @deffn {Scheme Procedure} cat-avatar-generator-service @
  19349. [#:cache-dir "/var/cache/cat-avatar-generator"] @
  19350. [#:package cat-avatar-generator] @
  19351. [#:configuration (nginx-server-configuration)]
  19352. Returns an nginx-server-configuration that inherits @code{configuration}. It
  19353. extends the nginx configuration to add a server block that serves @code{package},
  19354. a version of cat-avatar-generator. During execution, cat-avatar-generator will
  19355. be able to use @code{cache-dir} as its cache directory.
  19356. @end deffn
  19357. A simple setup for cat-avatar-generator can look like this:
  19358. @lisp
  19359. (services (cons* (cat-avatar-generator-service
  19360. #:configuration
  19361. (nginx-server-configuration
  19362. (server-name '("example.com"))))
  19363. ...
  19364. %base-services))
  19365. @end lisp
  19366. @subsubheading Hpcguix-web
  19367. @cindex hpcguix-web
  19368. The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
  19369. program is a customizable web interface to browse Guix packages,
  19370. initially designed for users of high-performance computing (HPC)
  19371. clusters.
  19372. @defvr {Scheme Variable} hpcguix-web-service-type
  19373. The service type for @code{hpcguix-web}.
  19374. @end defvr
  19375. @deftp {Data Type} hpcguix-web-configuration
  19376. Data type for the hpcguix-web service configuration.
  19377. @table @asis
  19378. @item @code{specs}
  19379. A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
  19380. configuration. The main items available in this spec are:
  19381. @table @asis
  19382. @item @code{title-prefix} (default: @code{"hpcguix | "})
  19383. The page title prefix.
  19384. @item @code{guix-command} (default: @code{"guix"})
  19385. The @command{guix} command.
  19386. @item @code{package-filter-proc} (default: @code{(const #t)})
  19387. A procedure specifying how to filter packages that are displayed.
  19388. @item @code{package-page-extension-proc} (default: @code{(const '())})
  19389. Extension package for @code{hpcguix-web}.
  19390. @item @code{menu} (default: @code{'()})
  19391. Additional entry in page @code{menu}.
  19392. @item @code{channels} (default: @code{%default-channels})
  19393. List of channels from which the package list is built (@pxref{Channels}).
  19394. @item @code{package-list-expiration} (default: @code{(* 12 3600)})
  19395. The expiration time, in seconds, after which the package list is rebuilt from
  19396. the latest instances of the given channels.
  19397. @end table
  19398. See the hpcguix-web repository for a
  19399. @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
  19400. complete example}.
  19401. @item @code{package} (default: @code{hpcguix-web})
  19402. The hpcguix-web package to use.
  19403. @end table
  19404. @end deftp
  19405. A typical hpcguix-web service declaration looks like this:
  19406. @lisp
  19407. (service hpcguix-web-service-type
  19408. (hpcguix-web-configuration
  19409. (specs
  19410. #~(define site-config
  19411. (hpcweb-configuration
  19412. (title-prefix "Guix-HPC - ")
  19413. (menu '(("/about" "ABOUT"))))))))
  19414. @end lisp
  19415. @quotation Note
  19416. The hpcguix-web service periodically updates the package list it publishes by
  19417. pulling channels from Git. To that end, it needs to access X.509 certificates
  19418. so that it can authenticate Git servers when communicating over HTTPS, and it
  19419. assumes that @file{/etc/ssl/certs} contains those certificates.
  19420. Thus, make sure to add @code{nss-certs} or another certificate package to the
  19421. @code{packages} field of your configuration. @ref{X.509 Certificates}, for
  19422. more information on X.509 certificates.
  19423. @end quotation
  19424. @subsubheading gmnisrv
  19425. @cindex gmnisrv
  19426. The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
  19427. simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
  19428. @deffn {Scheme Variable} gmnisrv-service-type
  19429. This is the type of the gmnisrv service, whose value should be a
  19430. @code{gmnisrv-configuration} object, as in this example:
  19431. @lisp
  19432. (service gmnisrv-service-type
  19433. (gmnisrv-configuration
  19434. (config-file (local-file "./my-gmnisrv.ini"))))
  19435. @end lisp
  19436. @end deffn
  19437. @deftp {Data Type} gmnisrv-configuration
  19438. Data type representing the configuration of gmnisrv.
  19439. @table @asis
  19440. @item @code{package} (default: @var{gmnisrv})
  19441. Package object of the gmnisrv server.
  19442. @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
  19443. File-like object of the gmnisrv configuration file to use. The default
  19444. configuration listens on port 1965 and serves files from
  19445. @file{/srv/gemini}. Certificates are stored in
  19446. @file{/var/lib/gemini/certs}. For more information, run @command{man
  19447. gmnisrv} and @command{man gmnisrv.ini}.
  19448. @end table
  19449. @end deftp
  19450. @node Certificate Services
  19451. @subsection Certificate Services
  19452. @cindex Web
  19453. @cindex HTTP, HTTPS
  19454. @cindex Let's Encrypt
  19455. @cindex TLS certificates
  19456. The @code{(gnu services certbot)} module provides a service to
  19457. automatically obtain a valid TLS certificate from the Let's Encrypt
  19458. certificate authority. These certificates can then be used to serve
  19459. content securely over HTTPS or other TLS-based protocols, with the
  19460. knowledge that the client will be able to verify the server's
  19461. authenticity.
  19462. @url{https://letsencrypt.org/, Let's Encrypt} provides the
  19463. @code{certbot} tool to automate the certification process. This tool
  19464. first securely generates a key on the server. It then makes a request
  19465. to the Let's Encrypt certificate authority (CA) to sign the key. The CA
  19466. checks that the request originates from the host in question by using a
  19467. challenge-response protocol, requiring the server to provide its
  19468. response over HTTP@. If that protocol completes successfully, the CA
  19469. signs the key, resulting in a certificate. That certificate is valid
  19470. for a limited period of time, and therefore to continue to provide TLS
  19471. services, the server needs to periodically ask the CA to renew its
  19472. signature.
  19473. The certbot service automates this process: the initial key
  19474. generation, the initial certification request to the Let's Encrypt
  19475. service, the web server challenge/response integration, writing the
  19476. certificate to disk, the automated periodic renewals, and the deployment
  19477. tasks associated with the renewal (e.g.@: reloading services, copying keys
  19478. with different permissions).
  19479. Certbot is run twice a day, at a random minute within the hour. It
  19480. won't do anything until your certificates are due for renewal or
  19481. revoked, but running it regularly would give your service a chance of
  19482. staying online in case a Let's Encrypt-initiated revocation happened for
  19483. some reason.
  19484. By using this service, you agree to the ACME Subscriber Agreement, which
  19485. can be found there:
  19486. @url{https://acme-v01.api.letsencrypt.org/directory}.
  19487. @defvr {Scheme Variable} certbot-service-type
  19488. A service type for the @code{certbot} Let's Encrypt client. Its value
  19489. must be a @code{certbot-configuration} record as in this example:
  19490. @lisp
  19491. (define %nginx-deploy-hook
  19492. (program-file
  19493. "nginx-deploy-hook"
  19494. #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
  19495. (kill pid SIGHUP))))
  19496. (service certbot-service-type
  19497. (certbot-configuration
  19498. (email "foo@@example.net")
  19499. (certificates
  19500. (list
  19501. (certificate-configuration
  19502. (domains '("example.net" "www.example.net"))
  19503. (deploy-hook %nginx-deploy-hook))
  19504. (certificate-configuration
  19505. (domains '("bar.example.net")))))))
  19506. @end lisp
  19507. See below for details about @code{certbot-configuration}.
  19508. @end defvr
  19509. @deftp {Data Type} certbot-configuration
  19510. Data type representing the configuration of the @code{certbot} service.
  19511. This type has the following parameters:
  19512. @table @asis
  19513. @item @code{package} (default: @code{certbot})
  19514. The certbot package to use.
  19515. @item @code{webroot} (default: @code{/var/www})
  19516. The directory from which to serve the Let's Encrypt challenge/response
  19517. files.
  19518. @item @code{certificates} (default: @code{()})
  19519. A list of @code{certificates-configuration}s for which to generate
  19520. certificates and request signatures. Each certificate has a @code{name}
  19521. and several @code{domains}.
  19522. @item @code{email} (default: @code{#f})
  19523. Optional email address used for registration and recovery contact.
  19524. Setting this is encouraged as it allows you to receive important
  19525. notifications about the account and issued certificates.
  19526. @item @code{server} (default: @code{#f})
  19527. Optional URL of ACME server. Setting this overrides certbot's default,
  19528. which is the Let's Encrypt server.
  19529. @item @code{rsa-key-size} (default: @code{2048})
  19530. Size of the RSA key.
  19531. @item @code{default-location} (default: @i{see below})
  19532. The default @code{nginx-location-configuration}. Because @code{certbot}
  19533. needs to be able to serve challenges and responses, it needs to be able
  19534. to run a web server. It does so by extending the @code{nginx} web
  19535. service with an @code{nginx-server-configuration} listening on the
  19536. @var{domains} on port 80, and which has a
  19537. @code{nginx-location-configuration} for the @code{/.well-known/} URI
  19538. path subspace used by Let's Encrypt. @xref{Web Services}, for more on
  19539. these nginx configuration data types.
  19540. Requests to other URL paths will be matched by the
  19541. @code{default-location}, which if present is added to all
  19542. @code{nginx-server-configuration}s.
  19543. By default, the @code{default-location} will issue a redirect from
  19544. @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
  19545. you to define what to serve on your site via @code{https}.
  19546. Pass @code{#f} to not issue a default location.
  19547. @end table
  19548. @end deftp
  19549. @deftp {Data Type} certificate-configuration
  19550. Data type representing the configuration of a certificate.
  19551. This type has the following parameters:
  19552. @table @asis
  19553. @item @code{name} (default: @i{see below})
  19554. This name is used by Certbot for housekeeping and in file paths; it
  19555. doesn't affect the content of the certificate itself. To see
  19556. certificate names, run @code{certbot certificates}.
  19557. Its default is the first provided domain.
  19558. @item @code{domains} (default: @code{()})
  19559. The first domain provided will be the subject CN of the certificate, and
  19560. all domains will be Subject Alternative Names on the certificate.
  19561. @item @code{challenge} (default: @code{#f})
  19562. The challenge type that has to be run by certbot. If @code{#f} is specified,
  19563. default to the HTTP challenge. If a value is specified, defaults to the
  19564. manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
  19565. the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
  19566. and gives Let's Encrypt permission to log the public IP address of the
  19567. requesting machine.
  19568. @item @code{authentication-hook} (default: @code{#f})
  19569. Command to be run in a shell once for each certificate challenge to be
  19570. answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
  19571. will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
  19572. contains the validation string and @code{$CERTBOT_TOKEN} contains the
  19573. file name of the resource requested when performing an HTTP-01 challenge.
  19574. @item @code{cleanup-hook} (default: @code{#f})
  19575. Command to be run in a shell once for each certificate challenge that
  19576. have been answered by the @code{auth-hook}. For this command, the shell
  19577. variables available in the @code{auth-hook} script are still available, and
  19578. additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
  19579. of the @code{auth-hook} script.
  19580. @item @code{deploy-hook} (default: @code{#f})
  19581. Command to be run in a shell once for each successfully issued
  19582. certificate. For this command, the shell variable
  19583. @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
  19584. example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
  19585. certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
  19586. contain a space-delimited list of renewed certificate domains (for
  19587. example, @samp{"example.com www.example.com"}.
  19588. @end table
  19589. @end deftp
  19590. For each @code{certificate-configuration}, the certificate is saved to
  19591. @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
  19592. saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
  19593. @node DNS Services
  19594. @subsection DNS Services
  19595. @cindex DNS (domain name system)
  19596. @cindex domain name system (DNS)
  19597. The @code{(gnu services dns)} module provides services related to the
  19598. @dfn{domain name system} (DNS). It provides a server service for hosting
  19599. an @emph{authoritative} DNS server for multiple zones, slave or master.
  19600. This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
  19601. caching and forwarding DNS server for the LAN, which uses
  19602. @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
  19603. @subsubheading Knot Service
  19604. An example configuration of an authoritative server for two zones, one master
  19605. and one slave, is:
  19606. @lisp
  19607. (define-zone-entries example.org.zone
  19608. ;; Name TTL Class Type Data
  19609. ("@@" "" "IN" "A" "127.0.0.1")
  19610. ("@@" "" "IN" "NS" "ns")
  19611. ("ns" "" "IN" "A" "127.0.0.1"))
  19612. (define master-zone
  19613. (knot-zone-configuration
  19614. (domain "example.org")
  19615. (zone (zone-file
  19616. (origin "example.org")
  19617. (entries example.org.zone)))))
  19618. (define slave-zone
  19619. (knot-zone-configuration
  19620. (domain "plop.org")
  19621. (dnssec-policy "default")
  19622. (master (list "plop-master"))))
  19623. (define plop-master
  19624. (knot-remote-configuration
  19625. (id "plop-master")
  19626. (address (list "208.76.58.171"))))
  19627. (operating-system
  19628. ;; ...
  19629. (services (cons* (service knot-service-type
  19630. (knot-configuration
  19631. (remotes (list plop-master))
  19632. (zones (list master-zone slave-zone))))
  19633. ;; ...
  19634. %base-services)))
  19635. @end lisp
  19636. @deffn {Scheme Variable} knot-service-type
  19637. This is the type for the Knot DNS server.
  19638. Knot DNS is an authoritative DNS server, meaning that it can serve multiple
  19639. zones, that is to say domain names you would buy from a registrar. This server
  19640. is not a resolver, meaning that it can only resolve names for which it is
  19641. authoritative. This server can be configured to serve zones as a master server
  19642. or a slave server as a per-zone basis. Slave zones will get their data from
  19643. masters, and will serve it as an authoritative server. From the point of view
  19644. of a resolver, there is no difference between master and slave.
  19645. The following data types are used to configure the Knot DNS server:
  19646. @end deffn
  19647. @deftp {Data Type} knot-key-configuration
  19648. Data type representing a key.
  19649. This type has the following parameters:
  19650. @table @asis
  19651. @item @code{id} (default: @code{""})
  19652. An identifier for other configuration fields to refer to this key. IDs must
  19653. be unique and must not be empty.
  19654. @item @code{algorithm} (default: @code{#f})
  19655. The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
  19656. @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
  19657. and @code{'hmac-sha512}.
  19658. @item @code{secret} (default: @code{""})
  19659. The secret key itself.
  19660. @end table
  19661. @end deftp
  19662. @deftp {Data Type} knot-acl-configuration
  19663. Data type representing an Access Control List (ACL) configuration.
  19664. This type has the following parameters:
  19665. @table @asis
  19666. @item @code{id} (default: @code{""})
  19667. An identifier for other configuration fields to refer to this key. IDs must be
  19668. unique and must not be empty.
  19669. @item @code{address} (default: @code{'()})
  19670. An ordered list of IP addresses, network subnets, or network ranges represented
  19671. with strings. The query must match one of them. Empty value means that
  19672. address match is not required.
  19673. @item @code{key} (default: @code{'()})
  19674. An ordered list of references to keys represented with strings. The string
  19675. must match a key ID defined in a @code{knot-key-configuration}. No key means
  19676. that a key is not require to match that ACL.
  19677. @item @code{action} (default: @code{'()})
  19678. An ordered list of actions that are permitted or forbidden by this ACL@. Possible
  19679. values are lists of zero or more elements from @code{'transfer}, @code{'notify}
  19680. and @code{'update}.
  19681. @item @code{deny?} (default: @code{#f})
  19682. When true, the ACL defines restrictions. Listed actions are forbidden. When
  19683. false, listed actions are allowed.
  19684. @end table
  19685. @end deftp
  19686. @deftp {Data Type} zone-entry
  19687. Data type representing a record entry in a zone file.
  19688. This type has the following parameters:
  19689. @table @asis
  19690. @item @code{name} (default: @code{"@@"})
  19691. The name of the record. @code{"@@"} refers to the origin of the zone. Names
  19692. are relative to the origin of the zone. For example, in the @code{example.org}
  19693. zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
  19694. Names ending with a dot are absolute, which means that @code{"ns.example.org."}
  19695. refers to @code{ns.example.org}.
  19696. @item @code{ttl} (default: @code{""})
  19697. The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
  19698. @item @code{class} (default: @code{"IN"})
  19699. The class of the record. Knot currently supports only @code{"IN"} and
  19700. partially @code{"CH"}.
  19701. @item @code{type} (default: @code{"A"})
  19702. The type of the record. Common types include A (IPv4 address), AAAA (IPv6
  19703. address), NS (Name Server) and MX (Mail eXchange). Many other types are
  19704. defined.
  19705. @item @code{data} (default: @code{""})
  19706. The data contained in the record. For instance an IP address associated with
  19707. an A record, or a domain name associated with an NS record. Remember that
  19708. domain names are relative to the origin unless they end with a dot.
  19709. @end table
  19710. @end deftp
  19711. @deftp {Data Type} zone-file
  19712. Data type representing the content of a zone file.
  19713. This type has the following parameters:
  19714. @table @asis
  19715. @item @code{entries} (default: @code{'()})
  19716. The list of entries. The SOA record is taken care of, so you don't need to
  19717. put it in the list of entries. This list should probably contain an entry
  19718. for your primary authoritative DNS server. Other than using a list of entries
  19719. directly, you can use @code{define-zone-entries} to define a object containing
  19720. the list of entries more easily, that you can later pass to the @code{entries}
  19721. field of the @code{zone-file}.
  19722. @item @code{origin} (default: @code{""})
  19723. The name of your zone. This parameter cannot be empty.
  19724. @item @code{ns} (default: @code{"ns"})
  19725. The domain of your primary authoritative DNS server. The name is relative to
  19726. the origin, unless it ends with a dot. It is mandatory that this primary
  19727. DNS server corresponds to an NS record in the zone and that it is associated
  19728. to an IP address in the list of entries.
  19729. @item @code{mail} (default: @code{"hostmaster"})
  19730. An email address people can contact you at, as the owner of the zone. This
  19731. is translated as @code{<mail>@@<origin>}.
  19732. @item @code{serial} (default: @code{1})
  19733. The serial number of the zone. As this is used to keep track of changes by
  19734. both slaves and resolvers, it is mandatory that it @emph{never} decreases.
  19735. Always increment it when you make a change in your zone.
  19736. @item @code{refresh} (default: @code{(* 2 24 3600)})
  19737. The frequency at which slaves will do a zone transfer. This value is a number
  19738. of seconds. It can be computed by multiplications or with
  19739. @code{(string->duration)}.
  19740. @item @code{retry} (default: @code{(* 15 60)})
  19741. The period after which a slave will retry to contact its master when it fails
  19742. to do so a first time.
  19743. @item @code{expiry} (default: @code{(* 14 24 3600)})
  19744. Default TTL of records. Existing records are considered correct for at most
  19745. this amount of time. After this period, resolvers will invalidate their cache
  19746. and check again that it still exists.
  19747. @item @code{nx} (default: @code{3600})
  19748. Default TTL of inexistant records. This delay is usually short because you want
  19749. your new domains to reach everyone quickly.
  19750. @end table
  19751. @end deftp
  19752. @deftp {Data Type} knot-remote-configuration
  19753. Data type representing a remote configuration.
  19754. This type has the following parameters:
  19755. @table @asis
  19756. @item @code{id} (default: @code{""})
  19757. An identifier for other configuration fields to refer to this remote. IDs must
  19758. be unique and must not be empty.
  19759. @item @code{address} (default: @code{'()})
  19760. An ordered list of destination IP addresses. Addresses are tried in sequence.
  19761. An optional port can be given with the @@ separator. For instance:
  19762. @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
  19763. @item @code{via} (default: @code{'()})
  19764. An ordered list of source IP addresses. An empty list will have Knot choose
  19765. an appropriate source IP@. An optional port can be given with the @@ separator.
  19766. The default is to choose at random.
  19767. @item @code{key} (default: @code{#f})
  19768. A reference to a key, that is a string containing the identifier of a key
  19769. defined in a @code{knot-key-configuration} field.
  19770. @end table
  19771. @end deftp
  19772. @deftp {Data Type} knot-keystore-configuration
  19773. Data type representing a keystore to hold dnssec keys.
  19774. This type has the following parameters:
  19775. @table @asis
  19776. @item @code{id} (default: @code{""})
  19777. The id of the keystore. It must not be empty.
  19778. @item @code{backend} (default: @code{'pem})
  19779. The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
  19780. @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
  19781. The configuration string of the backend. An example for the PKCS#11 is:
  19782. @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
  19783. For the pem backend, the string represents a path in the file system.
  19784. @end table
  19785. @end deftp
  19786. @deftp {Data Type} knot-policy-configuration
  19787. Data type representing a dnssec policy. Knot DNS is able to automatically
  19788. sign your zones. It can either generate and manage your keys automatically or
  19789. use keys that you generate.
  19790. Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
  19791. used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
  19792. zone. In order to be trusted, the KSK needs to be present in the parent zone
  19793. (usually a top-level domain). If your registrar supports dnssec, you will
  19794. have to send them your KSK's hash so they can add a DS record in their zone.
  19795. This is not automated and need to be done each time you change your KSK.
  19796. The policy also defines the lifetime of keys. Usually, ZSK can be changed
  19797. easily and use weaker cryptographic functions (they use lower parameters) in
  19798. order to sign records quickly, so they are changed often. The KSK however
  19799. requires manual interaction with the registrar, so they are changed less often
  19800. and use stronger parameters because they sign only one record.
  19801. This type has the following parameters:
  19802. @table @asis
  19803. @item @code{id} (default: @code{""})
  19804. The id of the policy. It must not be empty.
  19805. @item @code{keystore} (default: @code{"default"})
  19806. A reference to a keystore, that is a string containing the identifier of a
  19807. keystore defined in a @code{knot-keystore-configuration} field. The
  19808. @code{"default"} identifier means the default keystore (a kasp database that
  19809. was setup by this service).
  19810. @item @code{manual?} (default: @code{#f})
  19811. Whether the key management is manual or automatic.
  19812. @item @code{single-type-signing?} (default: @code{#f})
  19813. When @code{#t}, use the Single-Type Signing Scheme.
  19814. @item @code{algorithm} (default: @code{"ecdsap256sha256"})
  19815. An algorithm of signing keys and issued signatures.
  19816. @item @code{ksk-size} (default: @code{256})
  19817. The length of the KSK@. Note that this value is correct for the default
  19818. algorithm, but would be unsecure for other algorithms.
  19819. @item @code{zsk-size} (default: @code{256})
  19820. The length of the ZSK@. Note that this value is correct for the default
  19821. algorithm, but would be unsecure for other algorithms.
  19822. @item @code{dnskey-ttl} (default: @code{'default})
  19823. The TTL value for DNSKEY records added into zone apex. The special
  19824. @code{'default} value means same as the zone SOA TTL.
  19825. @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
  19826. The period between ZSK publication and the next rollover initiation.
  19827. @item @code{propagation-delay} (default: @code{(* 24 3600)})
  19828. An extra delay added for each key rollover step. This value should be high
  19829. enough to cover propagation of data from the master server to all slaves.
  19830. @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
  19831. A validity period of newly issued signatures.
  19832. @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
  19833. A period how long before a signature expiration the signature will be refreshed.
  19834. @item @code{nsec3?} (default: @code{#f})
  19835. When @code{#t}, NSEC3 will be used instead of NSEC.
  19836. @item @code{nsec3-iterations} (default: @code{5})
  19837. The number of additional times the hashing is performed.
  19838. @item @code{nsec3-salt-length} (default: @code{8})
  19839. The length of a salt field in octets, which is appended to the original owner
  19840. name before hashing.
  19841. @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
  19842. The validity period of newly issued salt field.
  19843. @end table
  19844. @end deftp
  19845. @deftp {Data Type} knot-zone-configuration
  19846. Data type representing a zone served by Knot.
  19847. This type has the following parameters:
  19848. @table @asis
  19849. @item @code{domain} (default: @code{""})
  19850. The domain served by this configuration. It must not be empty.
  19851. @item @code{file} (default: @code{""})
  19852. The file where this zone is saved. This parameter is ignored by master zones.
  19853. Empty means default location that depends on the domain name.
  19854. @item @code{zone} (default: @code{(zone-file)})
  19855. The content of the zone file. This parameter is ignored by slave zones. It
  19856. must contain a zone-file record.
  19857. @item @code{master} (default: @code{'()})
  19858. A list of master remotes. When empty, this zone is a master. When set, this
  19859. zone is a slave. This is a list of remotes identifiers.
  19860. @item @code{ddns-master} (default: @code{#f})
  19861. The main master. When empty, it defaults to the first master in the list of
  19862. masters.
  19863. @item @code{notify} (default: @code{'()})
  19864. A list of slave remote identifiers.
  19865. @item @code{acl} (default: @code{'()})
  19866. A list of acl identifiers.
  19867. @item @code{semantic-checks?} (default: @code{#f})
  19868. When set, this adds more semantic checks to the zone.
  19869. @item @code{disable-any?} (default: @code{#f})
  19870. When set, this forbids queries of the ANY type.
  19871. @item @code{zonefile-sync} (default: @code{0})
  19872. The delay between a modification in memory and on disk. 0 means immediate
  19873. synchronization.
  19874. @item @code{zonefile-load} (default: @code{#f})
  19875. The way the zone file contents are applied during zone load. Possible values
  19876. are:
  19877. @itemize
  19878. @item @code{#f} for using the default value from Knot,
  19879. @item @code{'none} for not using the zone file at all,
  19880. @item @code{'difference} for computing the difference between already available
  19881. contents and zone contents and applying it to the current zone contents,
  19882. @item @code{'difference-no-serial} for the same as @code{'difference}, but
  19883. ignoring the SOA serial in the zone file, while the server takes care of it
  19884. automatically.
  19885. @item @code{'whole} for loading zone contents from the zone file.
  19886. @end itemize
  19887. @item @code{journal-content} (default: @code{#f})
  19888. The way the journal is used to store zone and its changes. Possible values
  19889. are @code{'none} to not use it at all, @code{'changes} to store changes and
  19890. @code{'all} to store contents. @code{#f} does not set this option, so the
  19891. default value from Knot is used.
  19892. @item @code{max-journal-usage} (default: @code{#f})
  19893. The maximum size for the journal on disk. @code{#f} does not set this option,
  19894. so the default value from Knot is used.
  19895. @item @code{max-journal-depth} (default: @code{#f})
  19896. The maximum size of the history. @code{#f} does not set this option, so the
  19897. default value from Knot is used.
  19898. @item @code{max-zone-size} (default: @code{#f})
  19899. The maximum size of the zone file. This limit is enforced for incoming
  19900. transfer and updates. @code{#f} does not set this option, so the default
  19901. value from Knot is used.
  19902. @item @code{dnssec-policy} (default: @code{#f})
  19903. A reference to a @code{knot-policy-configuration} record, or the special
  19904. name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
  19905. on this zone.
  19906. @item @code{serial-policy} (default: @code{'increment})
  19907. A policy between @code{'increment} and @code{'unixtime}.
  19908. @end table
  19909. @end deftp
  19910. @deftp {Data Type} knot-configuration
  19911. Data type representing the Knot configuration.
  19912. This type has the following parameters:
  19913. @table @asis
  19914. @item @code{knot} (default: @code{knot})
  19915. The Knot package.
  19916. @item @code{run-directory} (default: @code{"/var/run/knot"})
  19917. The run directory. This directory will be used for pid file and sockets.
  19918. @item @code{includes} (default: @code{'()})
  19919. A list of strings or file-like objects denoting other files that must be
  19920. included at the top of the configuration file.
  19921. @cindex secrets, Knot service
  19922. This can be used to manage secrets out-of-band. For example, secret
  19923. keys may be stored in an out-of-band file not managed by Guix, and
  19924. thus not visible in @file{/gnu/store}---e.g., you could store secret
  19925. key configuration in @file{/etc/knot/secrets.conf} and add this file
  19926. to the @code{includes} list.
  19927. One can generate a secret tsig key (for nsupdate and zone transfers with the
  19928. keymgr command from the knot package. Note that the package is not automatically
  19929. installed by the service. The following example shows how to generate a new
  19930. tsig key:
  19931. @example
  19932. keymgr -t mysecret > /etc/knot/secrets.conf
  19933. chmod 600 /etc/knot/secrets.conf
  19934. @end example
  19935. Also note that the generated key will be named @var{mysecret}, so it is the
  19936. name that needs to be used in the @var{key} field of the
  19937. @code{knot-acl-configuration} record and in other places that need to refer
  19938. to that key.
  19939. It can also be used to add configuration not supported by this interface.
  19940. @item @code{listen-v4} (default: @code{"0.0.0.0"})
  19941. An ip address on which to listen.
  19942. @item @code{listen-v6} (default: @code{"::"})
  19943. An ip address on which to listen.
  19944. @item @code{listen-port} (default: @code{53})
  19945. A port on which to listen.
  19946. @item @code{keys} (default: @code{'()})
  19947. The list of knot-key-configuration used by this configuration.
  19948. @item @code{acls} (default: @code{'()})
  19949. The list of knot-acl-configuration used by this configuration.
  19950. @item @code{remotes} (default: @code{'()})
  19951. The list of knot-remote-configuration used by this configuration.
  19952. @item @code{zones} (default: @code{'()})
  19953. The list of knot-zone-configuration used by this configuration.
  19954. @end table
  19955. @end deftp
  19956. @subsubheading Knot Resolver Service
  19957. @deffn {Scheme Variable} knot-resolver-service-type
  19958. This is the type of the knot resolver service, whose value should be
  19959. an @code{knot-resolver-configuration} object as in this example:
  19960. @lisp
  19961. (service knot-resolver-service-type
  19962. (knot-resolver-configuration
  19963. (kresd-config-file (plain-file "kresd.conf" "
  19964. net.listen('192.168.0.1', 5353)
  19965. user('knot-resolver', 'knot-resolver')
  19966. modules = @{ 'hints > iterate', 'stats', 'predict' @}
  19967. cache.size = 100 * MB
  19968. "))))
  19969. @end lisp
  19970. For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
  19971. @end deffn
  19972. @deftp {Data Type} knot-resolver-configuration
  19973. Data type representing the configuration of knot-resolver.
  19974. @table @asis
  19975. @item @code{package} (default: @var{knot-resolver})
  19976. Package object of the knot DNS resolver.
  19977. @item @code{kresd-config-file} (default: %kresd.conf)
  19978. File-like object of the kresd configuration file to use, by default it
  19979. will listen on @code{127.0.0.1} and @code{::1}.
  19980. @item @code{garbage-collection-interval} (default: 1000)
  19981. Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
  19982. @end table
  19983. @end deftp
  19984. @subsubheading Dnsmasq Service
  19985. @deffn {Scheme Variable} dnsmasq-service-type
  19986. This is the type of the dnsmasq service, whose value should be an
  19987. @code{dnsmasq-configuration} object as in this example:
  19988. @lisp
  19989. (service dnsmasq-service-type
  19990. (dnsmasq-configuration
  19991. (no-resolv? #t)
  19992. (servers '("192.168.1.1"))))
  19993. @end lisp
  19994. @end deffn
  19995. @deftp {Data Type} dnsmasq-configuration
  19996. Data type representing the configuration of dnsmasq.
  19997. @table @asis
  19998. @item @code{package} (default: @var{dnsmasq})
  19999. Package object of the dnsmasq server.
  20000. @item @code{no-hosts?} (default: @code{#f})
  20001. When true, don't read the hostnames in /etc/hosts.
  20002. @item @code{port} (default: @code{53})
  20003. The port to listen on. Setting this to zero completely disables DNS
  20004. responses, leaving only DHCP and/or TFTP functions.
  20005. @item @code{local-service?} (default: @code{#t})
  20006. Accept DNS queries only from hosts whose address is on a local subnet,
  20007. ie a subnet for which an interface exists on the server.
  20008. @item @code{listen-addresses} (default: @code{'()})
  20009. Listen on the given IP addresses.
  20010. @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
  20011. The file to read the IP address of the upstream nameservers from.
  20012. @item @code{no-resolv?} (default: @code{#f})
  20013. When true, don't read @var{resolv-file}.
  20014. @item @code{servers} (default: @code{'()})
  20015. Specify IP address of upstream servers directly.
  20016. @item @code{addresses} (default: @code{'()})
  20017. For each entry, specify an IP address to return for any host in the
  20018. given domains. Queries in the domains are never forwarded and always
  20019. replied to with the specified IP address.
  20020. This is useful for redirecting hosts locally, for example:
  20021. @lisp
  20022. (service dnsmasq-service-type
  20023. (dnsmasq-configuration
  20024. (addresses
  20025. '(; Redirect to a local web-server.
  20026. "/example.org/127.0.0.1"
  20027. ; Redirect subdomain to a specific IP.
  20028. "/subdomain.example.org/192.168.1.42"))))
  20029. @end lisp
  20030. Note that rules in @file{/etc/hosts} take precedence over this.
  20031. @item @code{cache-size} (default: @code{150})
  20032. Set the size of dnsmasq's cache. Setting the cache size to zero
  20033. disables caching.
  20034. @item @code{negative-cache?} (default: @code{#t})
  20035. When false, disable negative caching.
  20036. @item @code{tftp-enable?} (default: @code{#f})
  20037. Whether to enable the built-in TFTP server.
  20038. @item @code{tftp-no-fail?} (default: @code{#f})
  20039. If true, does not fail dnsmasq if the TFTP server could not start up.
  20040. @item @code{tftp-single-port?} (default: @code{#f})
  20041. Whether to use only one single port for TFTP.
  20042. @item @code{tftp-secure?} (default: @code{#f})
  20043. If true, only files owned by the user running the dnsmasq process are accessible.
  20044. If dnsmasq is being run as root, different rules apply:
  20045. @code{tftp-secure?} has no effect, but only files which have the
  20046. world-readable bit set are accessible.
  20047. @item @code{tftp-max} (default: @code{#f})
  20048. If set, sets the maximal number of concurrent connections allowed.
  20049. @item @code{tftp-mtu} (default: @code{#f})
  20050. If set, sets the MTU for TFTP packets to that value.
  20051. @item @code{tftp-no-blocksize?} (default: @code{#f})
  20052. If true, stops the TFTP server from negotiating the blocksize with a client.
  20053. @item @code{tftp-lowercase?} (default: @code{#f})
  20054. Whether to convert all filenames in TFTP requests to lowercase.
  20055. @item @code{tftp-port-range} (default: @code{#f})
  20056. If set, fixes the dynamical ports (one per client) to the given range
  20057. (@code{"<start>,<end>"}).
  20058. @item @code{tftp-root} (default: @code{/var/empty,lo})
  20059. Look for files to transfer using TFTP relative to the given directory.
  20060. When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
  20061. getting outside the specified root. Absolute paths (starting with @samp{/}) are
  20062. allowed, but they must be within the TFTP-root. If the optional interface
  20063. argument is given, the directory is only used for TFTP requests via that
  20064. interface.
  20065. @item @code{tftp-unique-root} (default: @code{#f})
  20066. If set, add the IP or hardware address of the TFTP client as a path component
  20067. on the end of the TFTP-root. Only valid if a TFTP root is set and the
  20068. directory exists. Defaults to adding IP address (in standard dotted-quad
  20069. format).
  20070. For instance, if @option{--tftp-root} is @samp{/tftp} and client
  20071. @samp{1.2.3.4} requests file @file{myfile} then the effective path will
  20072. be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
  20073. @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
  20074. append the MAC address instead, using lowercase zero padded digits
  20075. separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
  20076. resolving MAC addresses is only possible if the client is in the local
  20077. network or obtained a DHCP lease from dnsmasq.
  20078. @end table
  20079. @end deftp
  20080. @subsubheading ddclient Service
  20081. @cindex ddclient
  20082. The ddclient service described below runs the ddclient daemon, which takes
  20083. care of automatically updating DNS entries for service providers such as
  20084. @uref{https://dyn.com/dns/, Dyn}.
  20085. The following example show instantiates the service with its default
  20086. configuration:
  20087. @lisp
  20088. (service ddclient-service-type)
  20089. @end lisp
  20090. Note that ddclient needs to access credentials that are stored in a
  20091. @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
  20092. @code{secret-file} below). You are expected to create this file manually, in
  20093. an ``out-of-band'' fashion (you @emph{could} make this file part of the
  20094. service configuration, for instance by using @code{plain-file}, but it will be
  20095. world-readable @i{via} @file{/gnu/store}). See the examples in the
  20096. @file{share/ddclient} directory of the @code{ddclient} package.
  20097. @c %start of fragment
  20098. Available @code{ddclient-configuration} fields are:
  20099. @deftypevr {@code{ddclient-configuration} parameter} package ddclient
  20100. The ddclient package.
  20101. @end deftypevr
  20102. @deftypevr {@code{ddclient-configuration} parameter} integer daemon
  20103. The period after which ddclient will retry to check IP and domain name.
  20104. Defaults to @samp{300}.
  20105. @end deftypevr
  20106. @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
  20107. Use syslog for the output.
  20108. Defaults to @samp{#t}.
  20109. @end deftypevr
  20110. @deftypevr {@code{ddclient-configuration} parameter} string mail
  20111. Mail to user.
  20112. Defaults to @samp{"root"}.
  20113. @end deftypevr
  20114. @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
  20115. Mail failed update to user.
  20116. Defaults to @samp{"root"}.
  20117. @end deftypevr
  20118. @deftypevr {@code{ddclient-configuration} parameter} string pid
  20119. The ddclient PID file.
  20120. Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
  20121. @end deftypevr
  20122. @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
  20123. Enable SSL support.
  20124. Defaults to @samp{#t}.
  20125. @end deftypevr
  20126. @deftypevr {@code{ddclient-configuration} parameter} string user
  20127. Specifies the user name or ID that is used when running ddclient
  20128. program.
  20129. Defaults to @samp{"ddclient"}.
  20130. @end deftypevr
  20131. @deftypevr {@code{ddclient-configuration} parameter} string group
  20132. Group of the user who will run the ddclient program.
  20133. Defaults to @samp{"ddclient"}.
  20134. @end deftypevr
  20135. @deftypevr {@code{ddclient-configuration} parameter} string secret-file
  20136. Secret file which will be appended to @file{ddclient.conf} file. This
  20137. file contains credentials for use by ddclient. You are expected to
  20138. create it manually.
  20139. Defaults to @samp{"/etc/ddclient/secrets.conf"}.
  20140. @end deftypevr
  20141. @deftypevr {@code{ddclient-configuration} parameter} list extra-options
  20142. Extra options will be appended to @file{ddclient.conf} file.
  20143. Defaults to @samp{()}.
  20144. @end deftypevr
  20145. @c %end of fragment
  20146. @node VPN Services
  20147. @subsection VPN Services
  20148. @cindex VPN (virtual private network)
  20149. @cindex virtual private network (VPN)
  20150. The @code{(gnu services vpn)} module provides services related to
  20151. @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
  20152. your machine to connect to a VPN, and a @emph{server} service for your machine
  20153. to host a VPN@. Both services use @uref{https://openvpn.net/, OpenVPN}.
  20154. @deffn {Scheme Procedure} openvpn-client-service @
  20155. [#:config (openvpn-client-configuration)]
  20156. Return a service that runs @command{openvpn}, a VPN daemon, as a client.
  20157. @end deffn
  20158. @deffn {Scheme Procedure} openvpn-server-service @
  20159. [#:config (openvpn-server-configuration)]
  20160. Return a service that runs @command{openvpn}, a VPN daemon, as a server.
  20161. Both can be run simultaneously.
  20162. @end deffn
  20163. @c %automatically generated documentation
  20164. Available @code{openvpn-client-configuration} fields are:
  20165. @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
  20166. The OpenVPN package.
  20167. @end deftypevr
  20168. @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
  20169. The OpenVPN pid file.
  20170. Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
  20171. @end deftypevr
  20172. @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
  20173. The protocol (UDP or TCP) used to open a channel between clients and
  20174. servers.
  20175. Defaults to @samp{udp}.
  20176. @end deftypevr
  20177. @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
  20178. The device type used to represent the VPN connection.
  20179. Defaults to @samp{tun}.
  20180. @end deftypevr
  20181. If you do not have some of these files (eg.@: you use a username and
  20182. password), you can disable any of the following three fields by setting
  20183. it to @code{'disabled}.
  20184. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
  20185. The certificate authority to check connections against.
  20186. Defaults to @samp{"/etc/openvpn/ca.crt"}.
  20187. @end deftypevr
  20188. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
  20189. The certificate of the machine the daemon is running on. It should be
  20190. signed by the authority given in @code{ca}.
  20191. Defaults to @samp{"/etc/openvpn/client.crt"}.
  20192. @end deftypevr
  20193. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
  20194. The key of the machine the daemon is running on. It must be the key whose
  20195. certificate is @code{cert}.
  20196. Defaults to @samp{"/etc/openvpn/client.key"}.
  20197. @end deftypevr
  20198. @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
  20199. Whether to use the lzo compression algorithm.
  20200. Defaults to @samp{#t}.
  20201. @end deftypevr
  20202. @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
  20203. Don't re-read key files across SIGUSR1 or --ping-restart.
  20204. Defaults to @samp{#t}.
  20205. @end deftypevr
  20206. @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
  20207. Don't close and reopen TUN/TAP device or run up/down scripts across
  20208. SIGUSR1 or --ping-restart restarts.
  20209. Defaults to @samp{#t}.
  20210. @end deftypevr
  20211. @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
  20212. (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
  20213. poll/epoll/select prior to the write operation.
  20214. Defaults to @samp{#f}.
  20215. @end deftypevr
  20216. @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
  20217. Verbosity level.
  20218. Defaults to @samp{3}.
  20219. @end deftypevr
  20220. @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
  20221. Add an additional layer of HMAC authentication on top of the TLS control
  20222. channel to protect against DoS attacks.
  20223. Defaults to @samp{#f}.
  20224. @end deftypevr
  20225. @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
  20226. Authenticate with server using username/password. The option is a file
  20227. containing username/password on 2 lines. Do not use a file-like object as it
  20228. would be added to the store and readable by any user.
  20229. Defaults to @samp{'disabled}.
  20230. @end deftypevr
  20231. @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
  20232. Whether to check the server certificate has server usage extension.
  20233. Defaults to @samp{#t}.
  20234. @end deftypevr
  20235. @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
  20236. Bind to a specific local port number.
  20237. Defaults to @samp{#f}.
  20238. @end deftypevr
  20239. @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
  20240. Retry resolving server address.
  20241. Defaults to @samp{#t}.
  20242. @end deftypevr
  20243. @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
  20244. A list of remote servers to connect to.
  20245. Defaults to @samp{()}.
  20246. Available @code{openvpn-remote-configuration} fields are:
  20247. @deftypevr {@code{openvpn-remote-configuration} parameter} string name
  20248. Server name.
  20249. Defaults to @samp{"my-server"}.
  20250. @end deftypevr
  20251. @deftypevr {@code{openvpn-remote-configuration} parameter} number port
  20252. Port number the server listens to.
  20253. Defaults to @samp{1194}.
  20254. @end deftypevr
  20255. @end deftypevr
  20256. @c %end of automatic openvpn-client documentation
  20257. @c %automatically generated documentation
  20258. Available @code{openvpn-server-configuration} fields are:
  20259. @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
  20260. The OpenVPN package.
  20261. @end deftypevr
  20262. @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
  20263. The OpenVPN pid file.
  20264. Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
  20265. @end deftypevr
  20266. @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
  20267. The protocol (UDP or TCP) used to open a channel between clients and
  20268. servers.
  20269. Defaults to @samp{udp}.
  20270. @end deftypevr
  20271. @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
  20272. The device type used to represent the VPN connection.
  20273. Defaults to @samp{tun}.
  20274. @end deftypevr
  20275. If you do not have some of these files (eg.@: you use a username and
  20276. password), you can disable any of the following three fields by setting
  20277. it to @code{'disabled}.
  20278. @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
  20279. The certificate authority to check connections against.
  20280. Defaults to @samp{"/etc/openvpn/ca.crt"}.
  20281. @end deftypevr
  20282. @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
  20283. The certificate of the machine the daemon is running on. It should be
  20284. signed by the authority given in @code{ca}.
  20285. Defaults to @samp{"/etc/openvpn/client.crt"}.
  20286. @end deftypevr
  20287. @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
  20288. The key of the machine the daemon is running on. It must be the key whose
  20289. certificate is @code{cert}.
  20290. Defaults to @samp{"/etc/openvpn/client.key"}.
  20291. @end deftypevr
  20292. @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
  20293. Whether to use the lzo compression algorithm.
  20294. Defaults to @samp{#t}.
  20295. @end deftypevr
  20296. @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
  20297. Don't re-read key files across SIGUSR1 or --ping-restart.
  20298. Defaults to @samp{#t}.
  20299. @end deftypevr
  20300. @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
  20301. Don't close and reopen TUN/TAP device or run up/down scripts across
  20302. SIGUSR1 or --ping-restart restarts.
  20303. Defaults to @samp{#t}.
  20304. @end deftypevr
  20305. @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
  20306. (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
  20307. poll/epoll/select prior to the write operation.
  20308. Defaults to @samp{#f}.
  20309. @end deftypevr
  20310. @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
  20311. Verbosity level.
  20312. Defaults to @samp{3}.
  20313. @end deftypevr
  20314. @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
  20315. Add an additional layer of HMAC authentication on top of the TLS control
  20316. channel to protect against DoS attacks.
  20317. Defaults to @samp{#f}.
  20318. @end deftypevr
  20319. @deftypevr {@code{openvpn-server-configuration} parameter} number port
  20320. Specifies the port number on which the server listens.
  20321. Defaults to @samp{1194}.
  20322. @end deftypevr
  20323. @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
  20324. An ip and mask specifying the subnet inside the virtual network.
  20325. Defaults to @samp{"10.8.0.0 255.255.255.0"}.
  20326. @end deftypevr
  20327. @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
  20328. A CIDR notation specifying the IPv6 subnet inside the virtual network.
  20329. Defaults to @samp{#f}.
  20330. @end deftypevr
  20331. @deftypevr {@code{openvpn-server-configuration} parameter} string dh
  20332. The Diffie-Hellman parameters file.
  20333. Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
  20334. @end deftypevr
  20335. @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
  20336. The file that records client IPs.
  20337. Defaults to @samp{"/etc/openvpn/ipp.txt"}.
  20338. @end deftypevr
  20339. @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
  20340. When true, the server will act as a gateway for its clients.
  20341. Defaults to @samp{#f}.
  20342. @end deftypevr
  20343. @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
  20344. When true, clients are allowed to talk to each other inside the VPN.
  20345. Defaults to @samp{#f}.
  20346. @end deftypevr
  20347. @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
  20348. Causes ping-like messages to be sent back and forth over the link so
  20349. that each side knows when the other side has gone down. @code{keepalive}
  20350. requires a pair. The first element is the period of the ping sending,
  20351. and the second element is the timeout before considering the other side
  20352. down.
  20353. @end deftypevr
  20354. @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
  20355. The maximum number of clients.
  20356. Defaults to @samp{100}.
  20357. @end deftypevr
  20358. @deftypevr {@code{openvpn-server-configuration} parameter} string status
  20359. The status file. This file shows a small report on current connection.
  20360. It is truncated and rewritten every minute.
  20361. Defaults to @samp{"/var/run/openvpn/status"}.
  20362. @end deftypevr
  20363. @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
  20364. The list of configuration for some clients.
  20365. Defaults to @samp{()}.
  20366. Available @code{openvpn-ccd-configuration} fields are:
  20367. @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
  20368. Client name.
  20369. Defaults to @samp{"client"}.
  20370. @end deftypevr
  20371. @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
  20372. Client own network
  20373. Defaults to @samp{#f}.
  20374. @end deftypevr
  20375. @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
  20376. Client VPN IP.
  20377. Defaults to @samp{#f}.
  20378. @end deftypevr
  20379. @end deftypevr
  20380. @c %end of automatic openvpn-server documentation
  20381. @node Network File System
  20382. @subsection Network File System
  20383. @cindex NFS
  20384. The @code{(gnu services nfs)} module provides the following services,
  20385. which are most commonly used in relation to mounting or exporting
  20386. directory trees as @dfn{network file systems} (NFS).
  20387. While it is possible to use the individual components that together make
  20388. up a Network File System service, we recommended to configure an NFS
  20389. server with the @code{nfs-service-type}.
  20390. @subsubheading NFS Service
  20391. @cindex NFS, server
  20392. The NFS service takes care of setting up all NFS component services,
  20393. kernel configuration file systems, and installs configuration files in
  20394. the locations that NFS expects.
  20395. @defvr {Scheme Variable} nfs-service-type
  20396. A service type for a complete NFS server.
  20397. @end defvr
  20398. @deftp {Data Type} nfs-configuration
  20399. This data type represents the configuration of the NFS service and all
  20400. of its subsystems.
  20401. It has the following parameters:
  20402. @table @asis
  20403. @item @code{nfs-utils} (default: @code{nfs-utils})
  20404. The nfs-utils package to use.
  20405. @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
  20406. If a list of string values is provided, the @command{rpc.nfsd} daemon
  20407. will be limited to supporting the given versions of the NFS protocol.
  20408. @item @code{exports} (default: @code{'()})
  20409. This is a list of directories the NFS server should export. Each entry
  20410. is a list consisting of two elements: a directory name and a string
  20411. containing all options. This is an example in which the directory
  20412. @file{/export} is served to all NFS clients as a read-only share:
  20413. @lisp
  20414. (nfs-configuration
  20415. (exports
  20416. '(("/export"
  20417. "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
  20418. @end lisp
  20419. @item @code{rpcmountd-port} (default: @code{#f})
  20420. The network port that the @command{rpc.mountd} daemon should use.
  20421. @item @code{rpcstatd-port} (default: @code{#f})
  20422. The network port that the @command{rpc.statd} daemon should use.
  20423. @item @code{rpcbind} (default: @code{rpcbind})
  20424. The rpcbind package to use.
  20425. @item @code{idmap-domain} (default: @code{"localdomain"})
  20426. The local NFSv4 domain name.
  20427. @item @code{nfsd-port} (default: @code{2049})
  20428. The network port that the @command{nfsd} daemon should use.
  20429. @item @code{nfsd-threads} (default: @code{8})
  20430. The number of threads used by the @command{nfsd} daemon.
  20431. @item @code{nfsd-tcp?} (default: @code{#t})
  20432. Whether the @command{nfsd} daemon should listen on a TCP socket.
  20433. @item @code{nfsd-udp?} (default: @code{#f})
  20434. Whether the @command{nfsd} daemon should listen on a UDP socket.
  20435. @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  20436. The directory where the pipefs file system is mounted.
  20437. @item @code{debug} (default: @code{'()"})
  20438. A list of subsystems for which debugging output should be enabled. This
  20439. is a list of symbols. Any of these symbols are valid: @code{nfsd},
  20440. @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
  20441. @end table
  20442. @end deftp
  20443. If you don't need a complete NFS service or prefer to build it yourself
  20444. you can use the individual component services that are documented below.
  20445. @subsubheading RPC Bind Service
  20446. @cindex rpcbind
  20447. The RPC Bind service provides a facility to map program numbers into
  20448. universal addresses.
  20449. Many NFS related services use this facility. Hence it is automatically
  20450. started when a dependent service starts.
  20451. @defvr {Scheme Variable} rpcbind-service-type
  20452. A service type for the RPC portmapper daemon.
  20453. @end defvr
  20454. @deftp {Data Type} rpcbind-configuration
  20455. Data type representing the configuration of the RPC Bind Service.
  20456. This type has the following parameters:
  20457. @table @asis
  20458. @item @code{rpcbind} (default: @code{rpcbind})
  20459. The rpcbind package to use.
  20460. @item @code{warm-start?} (default: @code{#t})
  20461. If this parameter is @code{#t}, then the daemon will read a
  20462. state file on startup thus reloading state information saved by a previous
  20463. instance.
  20464. @end table
  20465. @end deftp
  20466. @subsubheading Pipefs Pseudo File System
  20467. @cindex pipefs
  20468. @cindex rpc_pipefs
  20469. The pipefs file system is used to transfer NFS related data
  20470. between the kernel and user space programs.
  20471. @defvr {Scheme Variable} pipefs-service-type
  20472. A service type for the pipefs pseudo file system.
  20473. @end defvr
  20474. @deftp {Data Type} pipefs-configuration
  20475. Data type representing the configuration of the pipefs pseudo file system service.
  20476. This type has the following parameters:
  20477. @table @asis
  20478. @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  20479. The directory to which the file system is to be attached.
  20480. @end table
  20481. @end deftp
  20482. @subsubheading GSS Daemon Service
  20483. @cindex GSSD
  20484. @cindex GSS
  20485. @cindex global security system
  20486. The @dfn{global security system} (GSS) daemon provides strong security for RPC
  20487. based protocols.
  20488. Before exchanging RPC requests an RPC client must establish a security
  20489. context. Typically this is done using the Kerberos command @command{kinit}
  20490. or automatically at login time using PAM services (@pxref{Kerberos Services}).
  20491. @defvr {Scheme Variable} gss-service-type
  20492. A service type for the Global Security System (GSS) daemon.
  20493. @end defvr
  20494. @deftp {Data Type} gss-configuration
  20495. Data type representing the configuration of the GSS daemon service.
  20496. This type has the following parameters:
  20497. @table @asis
  20498. @item @code{nfs-utils} (default: @code{nfs-utils})
  20499. The package in which the @command{rpc.gssd} command is to be found.
  20500. @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  20501. The directory where the pipefs file system is mounted.
  20502. @end table
  20503. @end deftp
  20504. @subsubheading IDMAP Daemon Service
  20505. @cindex idmapd
  20506. @cindex name mapper
  20507. The idmap daemon service provides mapping between user IDs and user names.
  20508. Typically it is required in order to access file systems mounted via NFSv4.
  20509. @defvr {Scheme Variable} idmap-service-type
  20510. A service type for the Identity Mapper (IDMAP) daemon.
  20511. @end defvr
  20512. @deftp {Data Type} idmap-configuration
  20513. Data type representing the configuration of the IDMAP daemon service.
  20514. This type has the following parameters:
  20515. @table @asis
  20516. @item @code{nfs-utils} (default: @code{nfs-utils})
  20517. The package in which the @command{rpc.idmapd} command is to be found.
  20518. @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
  20519. The directory where the pipefs file system is mounted.
  20520. @item @code{domain} (default: @code{#f})
  20521. The local NFSv4 domain name.
  20522. This must be a string or @code{#f}.
  20523. If it is @code{#f} then the daemon will use the host's fully qualified domain name.
  20524. @item @code{verbosity} (default: @code{0})
  20525. The verbosity level of the daemon.
  20526. @end table
  20527. @end deftp
  20528. @node Continuous Integration
  20529. @subsection Continuous Integration
  20530. @cindex continuous integration
  20531. @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
  20532. continuous integration tool for Guix. It can be used both for development and
  20533. for providing substitutes to others (@pxref{Substitutes}).
  20534. The @code{(gnu services cuirass)} module provides the following service.
  20535. @defvr {Scheme Procedure} cuirass-service-type
  20536. The type of the Cuirass service. Its value must be a
  20537. @code{cuirass-configuration} object, as described below.
  20538. @end defvr
  20539. To add build jobs, you have to set the @code{specifications} field of the
  20540. configuration. Here is an example of a service that polls the Guix repository
  20541. and builds the packages from a manifest. Some of the packages are defined in
  20542. the @code{"custom-packages"} input, which is the equivalent of
  20543. @env{GUIX_PACKAGE_PATH}.
  20544. @lisp
  20545. (define %cuirass-specs
  20546. #~(list
  20547. '((#:name . "my-manifest")
  20548. (#:load-path-inputs . ("guix"))
  20549. (#:package-path-inputs . ("custom-packages"))
  20550. (#:proc-input . "guix")
  20551. (#:proc-file . "build-aux/cuirass/gnu-system.scm")
  20552. (#:proc . cuirass-jobs)
  20553. (#:proc-args . ((subset . "manifests")
  20554. (systems . ("x86_64-linux"))
  20555. (manifests . (("config" . "guix/manifest.scm")))))
  20556. (#:inputs . (((#:name . "guix")
  20557. (#:url . "git://git.savannah.gnu.org/guix.git")
  20558. (#:load-path . ".")
  20559. (#:branch . "master")
  20560. (#:no-compile? . #t))
  20561. ((#:name . "config")
  20562. (#:url . "https://git.example.org/config.git")
  20563. (#:load-path . ".")
  20564. (#:branch . "master")
  20565. (#:no-compile? . #t))
  20566. ((#:name . "custom-packages")
  20567. (#:url . "https://git.example.org/custom-packages.git")
  20568. (#:load-path . ".")
  20569. (#:branch . "master")
  20570. (#:no-compile? . #t)))))))
  20571. (service cuirass-service-type
  20572. (cuirass-configuration
  20573. (specifications %cuirass-specs)))
  20574. @end lisp
  20575. While information related to build jobs is located directly in the
  20576. specifications, global settings for the @command{cuirass} process are
  20577. accessible in other @code{cuirass-configuration} fields.
  20578. @deftp {Data Type} cuirass-configuration
  20579. Data type representing the configuration of Cuirass.
  20580. @table @asis
  20581. @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
  20582. Location of the log file.
  20583. @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
  20584. Location of the log file used by the web interface.
  20585. @item @code{queries-log-file} (default: @code{#f})
  20586. Location of the SQL queries log file. By default, SQL queries logging is
  20587. disabled.
  20588. @item @code{web-queries-log-file} (default: @code{#f})
  20589. Location of the web SQL queries log file. By default, web SQL queries
  20590. logging is disabled.
  20591. @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
  20592. Location of the repository cache.
  20593. @item @code{user} (default: @code{"cuirass"})
  20594. Owner of the @code{cuirass} process.
  20595. @item @code{group} (default: @code{"cuirass"})
  20596. Owner's group of the @code{cuirass} process.
  20597. @item @code{interval} (default: @code{60})
  20598. Number of seconds between the poll of the repositories followed by the
  20599. Cuirass jobs.
  20600. @item @code{queue-size} (default: @code{1})
  20601. Size of the database writer queue.
  20602. @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
  20603. Location of sqlite database which contains the build results and previously
  20604. added specifications.
  20605. @item @code{ttl} (default: @code{(* 30 24 3600)})
  20606. Specifies the time-to-live (TTL) in seconds of garbage collector roots that
  20607. are registered for build results. This means that build results are protected
  20608. from garbage collection for at least @var{ttl} seconds.
  20609. @item @code{port} (default: @code{8081})
  20610. Port number used by the HTTP server.
  20611. @item @code{host} (default: @code{"localhost"})
  20612. Listen on the network interface for @var{host}. The default is to
  20613. accept connections from localhost.
  20614. @item @code{specifications} (default: @code{#~'()})
  20615. A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
  20616. where a specification is an association list
  20617. (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
  20618. keys are keywords (@code{#:keyword-example}) as shown in the example
  20619. above.
  20620. @item @code{use-substitutes?} (default: @code{#f})
  20621. This allows using substitutes to avoid building every dependencies of a job
  20622. from source.
  20623. @item @code{one-shot?} (default: @code{#f})
  20624. Only evaluate specifications and build derivations once.
  20625. @item @code{fallback?} (default: @code{#f})
  20626. When substituting a pre-built binary fails, fall back to building
  20627. packages locally.
  20628. @item @code{extra-options} (default: @code{'()})
  20629. Extra options to pass when running the Cuirass processes.
  20630. @item @code{cuirass} (default: @code{cuirass})
  20631. The Cuirass package to use.
  20632. @end table
  20633. @end deftp
  20634. @node Power Management Services
  20635. @subsection Power Management Services
  20636. @cindex tlp
  20637. @cindex power management with TLP
  20638. @subsubheading TLP daemon
  20639. The @code{(gnu services pm)} module provides a Guix service definition
  20640. for the Linux power management tool TLP.
  20641. TLP enables various powersaving modes in userspace and kernel.
  20642. Contrary to @code{upower-service}, it is not a passive,
  20643. monitoring tool, as it will apply custom settings each time a new power
  20644. source is detected. More information can be found at
  20645. @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
  20646. @deffn {Scheme Variable} tlp-service-type
  20647. The service type for the TLP tool. The default settings are optimised
  20648. for battery life on most systems, but you can tweak them to your heart's
  20649. content by adding a valid @code{tlp-configuration}:
  20650. @lisp
  20651. (service tlp-service-type
  20652. (tlp-configuration
  20653. (cpu-scaling-governor-on-ac (list "performance"))
  20654. (sched-powersave-on-bat? #t)))
  20655. @end lisp
  20656. @end deffn
  20657. Each parameter definition is preceded by its type; for example,
  20658. @samp{boolean foo} indicates that the @code{foo} parameter
  20659. should be specified as a boolean. Types starting with
  20660. @code{maybe-} denote parameters that won't show up in TLP config file
  20661. when their value is @code{'disabled}.
  20662. @c The following documentation was initially generated by
  20663. @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
  20664. @c documentation is better, so we shouldn't hesitate to edit below as
  20665. @c needed. However if the change you want to make to this documentation
  20666. @c can be done in an automated way, it's probably easier to change
  20667. @c (generate-documentation) than to make it below and have to deal with
  20668. @c the churn as TLP updates.
  20669. Available @code{tlp-configuration} fields are:
  20670. @deftypevr {@code{tlp-configuration} parameter} package tlp
  20671. The TLP package.
  20672. @end deftypevr
  20673. @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
  20674. Set to true if you wish to enable TLP.
  20675. Defaults to @samp{#t}.
  20676. @end deftypevr
  20677. @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
  20678. Default mode when no power supply can be detected. Alternatives are AC
  20679. and BAT.
  20680. Defaults to @samp{"AC"}.
  20681. @end deftypevr
  20682. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
  20683. Number of seconds Linux kernel has to wait after the disk goes idle,
  20684. before syncing on AC.
  20685. Defaults to @samp{0}.
  20686. @end deftypevr
  20687. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
  20688. Same as @code{disk-idle-ac} but on BAT mode.
  20689. Defaults to @samp{2}.
  20690. @end deftypevr
  20691. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
  20692. Dirty pages flushing periodicity, expressed in seconds.
  20693. Defaults to @samp{15}.
  20694. @end deftypevr
  20695. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
  20696. Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
  20697. Defaults to @samp{60}.
  20698. @end deftypevr
  20699. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
  20700. CPU frequency scaling governor on AC mode. With intel_pstate driver,
  20701. alternatives are powersave and performance. With acpi-cpufreq driver,
  20702. alternatives are ondemand, powersave, performance and conservative.
  20703. Defaults to @samp{disabled}.
  20704. @end deftypevr
  20705. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
  20706. Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
  20707. Defaults to @samp{disabled}.
  20708. @end deftypevr
  20709. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
  20710. Set the min available frequency for the scaling governor on AC.
  20711. Defaults to @samp{disabled}.
  20712. @end deftypevr
  20713. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
  20714. Set the max available frequency for the scaling governor on AC.
  20715. Defaults to @samp{disabled}.
  20716. @end deftypevr
  20717. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
  20718. Set the min available frequency for the scaling governor on BAT.
  20719. Defaults to @samp{disabled}.
  20720. @end deftypevr
  20721. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
  20722. Set the max available frequency for the scaling governor on BAT.
  20723. Defaults to @samp{disabled}.
  20724. @end deftypevr
  20725. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
  20726. Limit the min P-state to control the power dissipation of the CPU, in AC
  20727. mode. Values are stated as a percentage of the available performance.
  20728. Defaults to @samp{disabled}.
  20729. @end deftypevr
  20730. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
  20731. Limit the max P-state to control the power dissipation of the CPU, in AC
  20732. mode. Values are stated as a percentage of the available performance.
  20733. Defaults to @samp{disabled}.
  20734. @end deftypevr
  20735. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
  20736. Same as @code{cpu-min-perf-on-ac} on BAT mode.
  20737. Defaults to @samp{disabled}.
  20738. @end deftypevr
  20739. @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
  20740. Same as @code{cpu-max-perf-on-ac} on BAT mode.
  20741. Defaults to @samp{disabled}.
  20742. @end deftypevr
  20743. @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
  20744. Enable CPU turbo boost feature on AC mode.
  20745. Defaults to @samp{disabled}.
  20746. @end deftypevr
  20747. @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
  20748. Same as @code{cpu-boost-on-ac?} on BAT mode.
  20749. Defaults to @samp{disabled}.
  20750. @end deftypevr
  20751. @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
  20752. Allow Linux kernel to minimize the number of CPU cores/hyper-threads
  20753. used under light load conditions.
  20754. Defaults to @samp{#f}.
  20755. @end deftypevr
  20756. @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
  20757. Same as @code{sched-powersave-on-ac?} but on BAT mode.
  20758. Defaults to @samp{#t}.
  20759. @end deftypevr
  20760. @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
  20761. Enable Linux kernel NMI watchdog.
  20762. Defaults to @samp{#f}.
  20763. @end deftypevr
  20764. @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
  20765. For Linux kernels with PHC patch applied, change CPU voltages. An
  20766. example value would be @samp{"F:V F:V F:V F:V"}.
  20767. Defaults to @samp{disabled}.
  20768. @end deftypevr
  20769. @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
  20770. Set CPU performance versus energy saving policy on AC@. Alternatives are
  20771. performance, normal, powersave.
  20772. Defaults to @samp{"performance"}.
  20773. @end deftypevr
  20774. @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
  20775. Same as @code{energy-perf-policy-ac} but on BAT mode.
  20776. Defaults to @samp{"powersave"}.
  20777. @end deftypevr
  20778. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
  20779. Hard disk devices.
  20780. @end deftypevr
  20781. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
  20782. Hard disk advanced power management level.
  20783. @end deftypevr
  20784. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
  20785. Same as @code{disk-apm-bat} but on BAT mode.
  20786. @end deftypevr
  20787. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
  20788. Hard disk spin down timeout. One value has to be specified for each
  20789. declared hard disk.
  20790. Defaults to @samp{disabled}.
  20791. @end deftypevr
  20792. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
  20793. Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
  20794. Defaults to @samp{disabled}.
  20795. @end deftypevr
  20796. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
  20797. Select IO scheduler for disk devices. One value has to be specified for
  20798. each declared hard disk. Example alternatives are cfq, deadline and
  20799. noop.
  20800. Defaults to @samp{disabled}.
  20801. @end deftypevr
  20802. @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
  20803. SATA aggressive link power management (ALPM) level. Alternatives are
  20804. min_power, medium_power, max_performance.
  20805. Defaults to @samp{"max_performance"}.
  20806. @end deftypevr
  20807. @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
  20808. Same as @code{sata-linkpwr-ac} but on BAT mode.
  20809. Defaults to @samp{"min_power"}.
  20810. @end deftypevr
  20811. @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
  20812. Exclude specified SATA host devices for link power management.
  20813. Defaults to @samp{disabled}.
  20814. @end deftypevr
  20815. @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
  20816. Enable Runtime Power Management for AHCI controller and disks on AC
  20817. mode.
  20818. Defaults to @samp{disabled}.
  20819. @end deftypevr
  20820. @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
  20821. Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
  20822. Defaults to @samp{disabled}.
  20823. @end deftypevr
  20824. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
  20825. Seconds of inactivity before disk is suspended.
  20826. Defaults to @samp{15}.
  20827. @end deftypevr
  20828. @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
  20829. PCI Express Active State Power Management level. Alternatives are
  20830. default, performance, powersave.
  20831. Defaults to @samp{"performance"}.
  20832. @end deftypevr
  20833. @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
  20834. Same as @code{pcie-aspm-ac} but on BAT mode.
  20835. Defaults to @samp{"powersave"}.
  20836. @end deftypevr
  20837. @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
  20838. Radeon graphics clock speed level. Alternatives are low, mid, high,
  20839. auto, default.
  20840. Defaults to @samp{"high"}.
  20841. @end deftypevr
  20842. @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
  20843. Same as @code{radeon-power-ac} but on BAT mode.
  20844. Defaults to @samp{"low"}.
  20845. @end deftypevr
  20846. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
  20847. Radeon dynamic power management method (DPM). Alternatives are battery,
  20848. performance.
  20849. Defaults to @samp{"performance"}.
  20850. @end deftypevr
  20851. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
  20852. Same as @code{radeon-dpm-state-ac} but on BAT mode.
  20853. Defaults to @samp{"battery"}.
  20854. @end deftypevr
  20855. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
  20856. Radeon DPM performance level. Alternatives are auto, low, high.
  20857. Defaults to @samp{"auto"}.
  20858. @end deftypevr
  20859. @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
  20860. Same as @code{radeon-dpm-perf-ac} but on BAT mode.
  20861. Defaults to @samp{"auto"}.
  20862. @end deftypevr
  20863. @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
  20864. Wifi power saving mode.
  20865. Defaults to @samp{#f}.
  20866. @end deftypevr
  20867. @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
  20868. Same as @code{wifi-power-ac?} but on BAT mode.
  20869. Defaults to @samp{#t}.
  20870. @end deftypevr
  20871. @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
  20872. Disable wake on LAN.
  20873. Defaults to @samp{#t}.
  20874. @end deftypevr
  20875. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
  20876. Timeout duration in seconds before activating audio power saving on
  20877. Intel HDA and AC97 devices. A value of 0 disables power saving.
  20878. Defaults to @samp{0}.
  20879. @end deftypevr
  20880. @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
  20881. Same as @code{sound-powersave-ac} but on BAT mode.
  20882. Defaults to @samp{1}.
  20883. @end deftypevr
  20884. @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
  20885. Disable controller in powersaving mode on Intel HDA devices.
  20886. Defaults to @samp{#t}.
  20887. @end deftypevr
  20888. @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
  20889. Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
  20890. powered on again by releasing (and reinserting) the eject lever or by
  20891. pressing the disc eject button on newer models.
  20892. Defaults to @samp{#f}.
  20893. @end deftypevr
  20894. @deftypevr {@code{tlp-configuration} parameter} string bay-device
  20895. Name of the optical drive device to power off.
  20896. Defaults to @samp{"sr0"}.
  20897. @end deftypevr
  20898. @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
  20899. Runtime Power Management for PCI(e) bus devices. Alternatives are on
  20900. and auto.
  20901. Defaults to @samp{"on"}.
  20902. @end deftypevr
  20903. @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
  20904. Same as @code{runtime-pm-ac} but on BAT mode.
  20905. Defaults to @samp{"auto"}.
  20906. @end deftypevr
  20907. @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
  20908. Runtime Power Management for all PCI(e) bus devices, except blacklisted
  20909. ones.
  20910. Defaults to @samp{#t}.
  20911. @end deftypevr
  20912. @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
  20913. Exclude specified PCI(e) device addresses from Runtime Power Management.
  20914. Defaults to @samp{disabled}.
  20915. @end deftypevr
  20916. @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
  20917. Exclude PCI(e) devices assigned to the specified drivers from Runtime
  20918. Power Management.
  20919. @end deftypevr
  20920. @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
  20921. Enable USB autosuspend feature.
  20922. Defaults to @samp{#t}.
  20923. @end deftypevr
  20924. @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
  20925. Exclude specified devices from USB autosuspend.
  20926. Defaults to @samp{disabled}.
  20927. @end deftypevr
  20928. @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
  20929. Exclude WWAN devices from USB autosuspend.
  20930. Defaults to @samp{#t}.
  20931. @end deftypevr
  20932. @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
  20933. Include specified devices into USB autosuspend, even if they are already
  20934. excluded by the driver or via @code{usb-blacklist-wwan?}.
  20935. Defaults to @samp{disabled}.
  20936. @end deftypevr
  20937. @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
  20938. Enable USB autosuspend before shutdown.
  20939. Defaults to @samp{disabled}.
  20940. @end deftypevr
  20941. @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
  20942. Restore radio device state (bluetooth, wifi, wwan) from previous
  20943. shutdown on system startup.
  20944. Defaults to @samp{#f}.
  20945. @end deftypevr
  20946. @cindex thermald
  20947. @cindex CPU frequency scaling with thermald
  20948. @subsubheading Thermald daemon
  20949. The @code{(gnu services pm)} module provides an interface to
  20950. thermald, a CPU frequency scaling service which helps prevent overheating.
  20951. @defvr {Scheme Variable} thermald-service-type
  20952. This is the service type for
  20953. @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
  20954. Thermal Daemon, which is responsible for controlling the thermal state
  20955. of processors and preventing overheating.
  20956. @end defvr
  20957. @deftp {Data Type} thermald-configuration
  20958. Data type representing the configuration of @code{thermald-service-type}.
  20959. @table @asis
  20960. @item @code{ignore-cpuid-check?} (default: @code{#f})
  20961. Ignore cpuid check for supported CPU models.
  20962. @item @code{thermald} (default: @var{thermald})
  20963. Package object of thermald.
  20964. @end table
  20965. @end deftp
  20966. @node Audio Services
  20967. @subsection Audio Services
  20968. The @code{(gnu services audio)} module provides a service to start MPD
  20969. (the Music Player Daemon).
  20970. @cindex mpd
  20971. @subsubheading Music Player Daemon
  20972. The Music Player Daemon (MPD) is a service that can play music while
  20973. being controlled from the local machine or over the network by a variety
  20974. of clients.
  20975. The following example shows how one might run @code{mpd} as user
  20976. @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
  20977. @lisp
  20978. (service mpd-service-type
  20979. (mpd-configuration
  20980. (user "bob")
  20981. (port "6666")))
  20982. @end lisp
  20983. @defvr {Scheme Variable} mpd-service-type
  20984. The service type for @command{mpd}
  20985. @end defvr
  20986. @deftp {Data Type} mpd-configuration
  20987. Data type representing the configuration of @command{mpd}.
  20988. @table @asis
  20989. @item @code{user} (default: @code{"mpd"})
  20990. The user to run mpd as.
  20991. @item @code{music-dir} (default: @code{"~/Music"})
  20992. The directory to scan for music files.
  20993. @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
  20994. The directory to store playlists.
  20995. @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
  20996. The location of the music database.
  20997. @item @code{state-file} (default: @code{"~/.mpd/state"})
  20998. The location of the file that stores current MPD's state.
  20999. @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
  21000. The location of the sticker database.
  21001. @item @code{port} (default: @code{"6600"})
  21002. The port to run mpd on.
  21003. @item @code{address} (default: @code{"any"})
  21004. The address that mpd will bind to. To use a Unix domain socket,
  21005. an absolute path can be specified here.
  21006. @item @code{outputs} (default: @code{"(list (mpd-output))"})
  21007. The audio outputs that MPD can use. By default this is a single output using pulseaudio.
  21008. @end table
  21009. @end deftp
  21010. @deftp {Data Type} mpd-output
  21011. Data type representing an @command{mpd} audio output.
  21012. @table @asis
  21013. @item @code{name} (default: @code{"MPD"})
  21014. The name of the audio output.
  21015. @item @code{type} (default: @code{"pulse"})
  21016. The type of audio output.
  21017. @item @code{enabled?} (default: @code{#t})
  21018. Specifies whether this audio output is enabled when MPD is started. By
  21019. default, all audio outputs are enabled. This is just the default
  21020. setting when there is no state file; with a state file, the previous
  21021. state is restored.
  21022. @item @code{tags?} (default: @code{#t})
  21023. If set to @code{#f}, then MPD will not send tags to this output. This
  21024. is only useful for output plugins that can receive tags, for example the
  21025. @code{httpd} output plugin.
  21026. @item @code{always-on?} (default: @code{#f})
  21027. If set to @code{#t}, then MPD attempts to keep this audio output always
  21028. open. This may be useful for streaming servers, when you don’t want to
  21029. disconnect all listeners even when playback is accidentally stopped.
  21030. @item @code{mixer-type}
  21031. This field accepts a symbol that specifies which mixer should be used
  21032. for this audio output: the @code{hardware} mixer, the @code{software}
  21033. mixer, the @code{null} mixer (allows setting the volume, but with no
  21034. effect; this can be used as a trick to implement an external mixer
  21035. External Mixer) or no mixer (@code{none}).
  21036. @item @code{extra-options} (default: @code{'()})
  21037. An association list of option symbols to string values to be appended to
  21038. the audio output configuration.
  21039. @end table
  21040. @end deftp
  21041. The following example shows a configuration of @code{mpd} that provides
  21042. an HTTP audio streaming output.
  21043. @lisp
  21044. (service mpd-service-type
  21045. (mpd-configuration
  21046. (outputs
  21047. (list (mpd-output
  21048. (name "streaming")
  21049. (type "httpd")
  21050. (mixer-type 'null)
  21051. (extra-options
  21052. `((encoder . "vorbis")
  21053. (port . "8080"))))))))
  21054. @end lisp
  21055. @node Virtualization Services
  21056. @subsection Virtualization Services
  21057. The @code{(gnu services virtualization)} module provides services for
  21058. the libvirt and virtlog daemons, as well as other virtualization-related
  21059. services.
  21060. @subsubheading Libvirt daemon
  21061. @code{libvirtd} is the server side daemon component of the libvirt
  21062. virtualization management system. This daemon runs on host servers
  21063. and performs required management tasks for virtualized guests.
  21064. @deffn {Scheme Variable} libvirt-service-type
  21065. This is the type of the @uref{https://libvirt.org, libvirt daemon}.
  21066. Its value must be a @code{libvirt-configuration}.
  21067. @lisp
  21068. (service libvirt-service-type
  21069. (libvirt-configuration
  21070. (unix-sock-group "libvirt")
  21071. (tls-port "16555")))
  21072. @end lisp
  21073. @end deffn
  21074. @c Auto-generated with (generate-libvirt-documentation)
  21075. Available @code{libvirt-configuration} fields are:
  21076. @deftypevr {@code{libvirt-configuration} parameter} package libvirt
  21077. Libvirt package.
  21078. @end deftypevr
  21079. @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
  21080. Flag listening for secure TLS connections on the public TCP/IP port.
  21081. You must set @code{listen} for this to have any effect.
  21082. It is necessary to setup a CA and issue server certificates before using
  21083. this capability.
  21084. Defaults to @samp{#t}.
  21085. @end deftypevr
  21086. @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
  21087. Listen for unencrypted TCP connections on the public TCP/IP port. You must
  21088. set @code{listen} for this to have any effect.
  21089. Using the TCP socket requires SASL authentication by default. Only SASL
  21090. mechanisms which support data encryption are allowed. This is
  21091. DIGEST_MD5 and GSSAPI (Kerberos5).
  21092. Defaults to @samp{#f}.
  21093. @end deftypevr
  21094. @deftypevr {@code{libvirt-configuration} parameter} string tls-port
  21095. Port for accepting secure TLS connections. This can be a port number,
  21096. or service name.
  21097. Defaults to @samp{"16514"}.
  21098. @end deftypevr
  21099. @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
  21100. Port for accepting insecure TCP connections. This can be a port number,
  21101. or service name.
  21102. Defaults to @samp{"16509"}.
  21103. @end deftypevr
  21104. @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
  21105. IP address or hostname used for client connections.
  21106. Defaults to @samp{"0.0.0.0"}.
  21107. @end deftypevr
  21108. @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
  21109. Flag toggling mDNS advertisement of the libvirt service.
  21110. Alternatively can disable for all services on a host by stopping the
  21111. Avahi daemon.
  21112. Defaults to @samp{#f}.
  21113. @end deftypevr
  21114. @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
  21115. Default mDNS advertisement name. This must be unique on the immediate
  21116. broadcast network.
  21117. Defaults to @samp{"Virtualization Host <hostname>"}.
  21118. @end deftypevr
  21119. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
  21120. UNIX domain socket group ownership. This can be used to allow a
  21121. 'trusted' set of users access to management capabilities without
  21122. becoming root.
  21123. Defaults to @samp{"root"}.
  21124. @end deftypevr
  21125. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
  21126. UNIX socket permissions for the R/O socket. This is used for monitoring
  21127. VM status only.
  21128. Defaults to @samp{"0777"}.
  21129. @end deftypevr
  21130. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
  21131. UNIX socket permissions for the R/W socket. Default allows only root.
  21132. If PolicyKit is enabled on the socket, the default will change to allow
  21133. everyone (eg, 0777)
  21134. Defaults to @samp{"0770"}.
  21135. @end deftypevr
  21136. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
  21137. UNIX socket permissions for the admin socket. Default allows only owner
  21138. (root), do not change it unless you are sure to whom you are exposing
  21139. the access to.
  21140. Defaults to @samp{"0777"}.
  21141. @end deftypevr
  21142. @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
  21143. The directory in which sockets will be found/created.
  21144. Defaults to @samp{"/var/run/libvirt"}.
  21145. @end deftypevr
  21146. @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
  21147. Authentication scheme for UNIX read-only sockets. By default socket
  21148. permissions allow anyone to connect
  21149. Defaults to @samp{"polkit"}.
  21150. @end deftypevr
  21151. @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
  21152. Authentication scheme for UNIX read-write sockets. By default socket
  21153. permissions only allow root. If PolicyKit support was compiled into
  21154. libvirt, the default will be to use 'polkit' auth.
  21155. Defaults to @samp{"polkit"}.
  21156. @end deftypevr
  21157. @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
  21158. Authentication scheme for TCP sockets. If you don't enable SASL, then
  21159. all TCP traffic is cleartext. Don't do this outside of a dev/test
  21160. scenario.
  21161. Defaults to @samp{"sasl"}.
  21162. @end deftypevr
  21163. @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
  21164. Authentication scheme for TLS sockets. TLS sockets already have
  21165. encryption provided by the TLS layer, and limited authentication is done
  21166. by certificates.
  21167. It is possible to make use of any SASL authentication mechanism as well,
  21168. by using 'sasl' for this option
  21169. Defaults to @samp{"none"}.
  21170. @end deftypevr
  21171. @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
  21172. API access control scheme.
  21173. By default an authenticated user is allowed access to all APIs. Access
  21174. drivers can place restrictions on this.
  21175. Defaults to @samp{()}.
  21176. @end deftypevr
  21177. @deftypevr {@code{libvirt-configuration} parameter} string key-file
  21178. Server key file path. If set to an empty string, then no private key is
  21179. loaded.
  21180. Defaults to @samp{""}.
  21181. @end deftypevr
  21182. @deftypevr {@code{libvirt-configuration} parameter} string cert-file
  21183. Server key file path. If set to an empty string, then no certificate is
  21184. loaded.
  21185. Defaults to @samp{""}.
  21186. @end deftypevr
  21187. @deftypevr {@code{libvirt-configuration} parameter} string ca-file
  21188. Server key file path. If set to an empty string, then no CA certificate
  21189. is loaded.
  21190. Defaults to @samp{""}.
  21191. @end deftypevr
  21192. @deftypevr {@code{libvirt-configuration} parameter} string crl-file
  21193. Certificate revocation list path. If set to an empty string, then no
  21194. CRL is loaded.
  21195. Defaults to @samp{""}.
  21196. @end deftypevr
  21197. @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
  21198. Disable verification of our own server certificates.
  21199. When libvirtd starts it performs some sanity checks against its own
  21200. certificates.
  21201. Defaults to @samp{#f}.
  21202. @end deftypevr
  21203. @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
  21204. Disable verification of client certificates.
  21205. Client certificate verification is the primary authentication mechanism.
  21206. Any client which does not present a certificate signed by the CA will be
  21207. rejected.
  21208. Defaults to @samp{#f}.
  21209. @end deftypevr
  21210. @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
  21211. Whitelist of allowed x509 Distinguished Name.
  21212. Defaults to @samp{()}.
  21213. @end deftypevr
  21214. @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
  21215. Whitelist of allowed SASL usernames. The format for username depends on
  21216. the SASL authentication mechanism.
  21217. Defaults to @samp{()}.
  21218. @end deftypevr
  21219. @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
  21220. Override the compile time default TLS priority string. The default is
  21221. usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
  21222. is desired for libvirt to deviate from the global default settings.
  21223. Defaults to @samp{"NORMAL"}.
  21224. @end deftypevr
  21225. @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
  21226. Maximum number of concurrent client connections to allow over all
  21227. sockets combined.
  21228. Defaults to @samp{5000}.
  21229. @end deftypevr
  21230. @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
  21231. Maximum length of queue of connections waiting to be accepted by the
  21232. daemon. Note, that some protocols supporting retransmission may obey
  21233. this so that a later reattempt at connection succeeds.
  21234. Defaults to @samp{1000}.
  21235. @end deftypevr
  21236. @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
  21237. Maximum length of queue of accepted but not yet authenticated clients.
  21238. Set this to zero to turn this feature off
  21239. Defaults to @samp{20}.
  21240. @end deftypevr
  21241. @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
  21242. Number of workers to start up initially.
  21243. Defaults to @samp{5}.
  21244. @end deftypevr
  21245. @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
  21246. Maximum number of worker threads.
  21247. If the number of active clients exceeds @code{min-workers}, then more
  21248. threads are spawned, up to max_workers limit. Typically you'd want
  21249. max_workers to equal maximum number of clients allowed.
  21250. Defaults to @samp{20}.
  21251. @end deftypevr
  21252. @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
  21253. Number of priority workers. If all workers from above pool are stuck,
  21254. some calls marked as high priority (notably domainDestroy) can be
  21255. executed in this pool.
  21256. Defaults to @samp{5}.
  21257. @end deftypevr
  21258. @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
  21259. Total global limit on concurrent RPC calls.
  21260. Defaults to @samp{20}.
  21261. @end deftypevr
  21262. @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
  21263. Limit on concurrent requests from a single client connection. To avoid
  21264. one client monopolizing the server this should be a small fraction of
  21265. the global max_requests and max_workers parameter.
  21266. Defaults to @samp{5}.
  21267. @end deftypevr
  21268. @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
  21269. Same as @code{min-workers} but for the admin interface.
  21270. Defaults to @samp{1}.
  21271. @end deftypevr
  21272. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
  21273. Same as @code{max-workers} but for the admin interface.
  21274. Defaults to @samp{5}.
  21275. @end deftypevr
  21276. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
  21277. Same as @code{max-clients} but for the admin interface.
  21278. Defaults to @samp{5}.
  21279. @end deftypevr
  21280. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
  21281. Same as @code{max-queued-clients} but for the admin interface.
  21282. Defaults to @samp{5}.
  21283. @end deftypevr
  21284. @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
  21285. Same as @code{max-client-requests} but for the admin interface.
  21286. Defaults to @samp{5}.
  21287. @end deftypevr
  21288. @deftypevr {@code{libvirt-configuration} parameter} integer log-level
  21289. Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
  21290. Defaults to @samp{3}.
  21291. @end deftypevr
  21292. @deftypevr {@code{libvirt-configuration} parameter} string log-filters
  21293. Logging filters.
  21294. A filter allows to select a different logging level for a given category
  21295. of logs. The format for a filter is one of:
  21296. @itemize @bullet
  21297. @item
  21298. x:name
  21299. @item
  21300. x:+name
  21301. @end itemize
  21302. where @code{name} is a string which is matched against the category
  21303. given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
  21304. file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
  21305. name in the filter can be a substring of the full category name, in
  21306. order to match multiple similar categories), the optional @samp{"+"}
  21307. prefix tells libvirt to log stack trace for each message matching name,
  21308. and @code{x} is the minimal level where matching messages should be
  21309. logged:
  21310. @itemize @bullet
  21311. @item
  21312. 1: DEBUG
  21313. @item
  21314. 2: INFO
  21315. @item
  21316. 3: WARNING
  21317. @item
  21318. 4: ERROR
  21319. @end itemize
  21320. Multiple filters can be defined in a single filters statement, they just
  21321. need to be separated by spaces.
  21322. Defaults to @samp{"3:remote 4:event"}.
  21323. @end deftypevr
  21324. @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
  21325. Logging outputs.
  21326. An output is one of the places to save logging information. The format
  21327. for an output can be:
  21328. @table @code
  21329. @item x:stderr
  21330. output goes to stderr
  21331. @item x:syslog:name
  21332. use syslog for the output and use the given name as the ident
  21333. @item x:file:file_path
  21334. output to a file, with the given filepath
  21335. @item x:journald
  21336. output to journald logging system
  21337. @end table
  21338. In all case the x prefix is the minimal level, acting as a filter
  21339. @itemize @bullet
  21340. @item
  21341. 1: DEBUG
  21342. @item
  21343. 2: INFO
  21344. @item
  21345. 3: WARNING
  21346. @item
  21347. 4: ERROR
  21348. @end itemize
  21349. Multiple outputs can be defined, they just need to be separated by
  21350. spaces.
  21351. Defaults to @samp{"3:stderr"}.
  21352. @end deftypevr
  21353. @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
  21354. Allows usage of the auditing subsystem to be altered
  21355. @itemize @bullet
  21356. @item
  21357. 0: disable all auditing
  21358. @item
  21359. 1: enable auditing, only if enabled on host
  21360. @item
  21361. 2: enable auditing, and exit if disabled on host.
  21362. @end itemize
  21363. Defaults to @samp{1}.
  21364. @end deftypevr
  21365. @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
  21366. Send audit messages via libvirt logging infrastructure.
  21367. Defaults to @samp{#f}.
  21368. @end deftypevr
  21369. @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
  21370. Host UUID@. UUID must not have all digits be the same.
  21371. Defaults to @samp{""}.
  21372. @end deftypevr
  21373. @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
  21374. Source to read host UUID.
  21375. @itemize @bullet
  21376. @item
  21377. @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
  21378. @item
  21379. @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
  21380. @end itemize
  21381. If @code{dmidecode} does not provide a valid UUID a temporary UUID will
  21382. be generated.
  21383. Defaults to @samp{"smbios"}.
  21384. @end deftypevr
  21385. @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
  21386. A keepalive message is sent to a client after @code{keepalive_interval}
  21387. seconds of inactivity to check if the client is still responding. If
  21388. set to -1, libvirtd will never send keepalive requests; however clients
  21389. can still send them and the daemon will send responses.
  21390. Defaults to @samp{5}.
  21391. @end deftypevr
  21392. @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
  21393. Maximum number of keepalive messages that are allowed to be sent to the
  21394. client without getting any response before the connection is considered
  21395. broken.
  21396. In other words, the connection is automatically closed approximately
  21397. after @code{keepalive_interval * (keepalive_count + 1)} seconds since
  21398. the last message received from the client. When @code{keepalive-count}
  21399. is set to 0, connections will be automatically closed after
  21400. @code{keepalive-interval} seconds of inactivity without sending any
  21401. keepalive messages.
  21402. Defaults to @samp{5}.
  21403. @end deftypevr
  21404. @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
  21405. Same as above but for admin interface.
  21406. Defaults to @samp{5}.
  21407. @end deftypevr
  21408. @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
  21409. Same as above but for admin interface.
  21410. Defaults to @samp{5}.
  21411. @end deftypevr
  21412. @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
  21413. Timeout for Open vSwitch calls.
  21414. The @code{ovs-vsctl} utility is used for the configuration and its
  21415. timeout option is set by default to 5 seconds to avoid potential
  21416. infinite waits blocking libvirt.
  21417. Defaults to @samp{5}.
  21418. @end deftypevr
  21419. @c %end of autogenerated docs
  21420. @subsubheading Virtlog daemon
  21421. The virtlogd service is a server side daemon component of libvirt that is
  21422. used to manage logs from virtual machine consoles.
  21423. This daemon is not used directly by libvirt client applications, rather it
  21424. is called on their behalf by @code{libvirtd}. By maintaining the logs in a
  21425. standalone daemon, the main @code{libvirtd} daemon can be restarted without
  21426. risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
  21427. itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
  21428. @deffn {Scheme Variable} virtlog-service-type
  21429. This is the type of the virtlog daemon.
  21430. Its value must be a @code{virtlog-configuration}.
  21431. @lisp
  21432. (service virtlog-service-type
  21433. (virtlog-configuration
  21434. (max-clients 1000)))
  21435. @end lisp
  21436. @end deffn
  21437. @deftypevr {@code{virtlog-configuration} parameter} integer log-level
  21438. Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
  21439. Defaults to @samp{3}.
  21440. @end deftypevr
  21441. @deftypevr {@code{virtlog-configuration} parameter} string log-filters
  21442. Logging filters.
  21443. A filter allows to select a different logging level for a given category
  21444. of logs The format for a filter is one of:
  21445. @itemize @bullet
  21446. @item
  21447. x:name
  21448. @item
  21449. x:+name
  21450. @end itemize
  21451. where @code{name} is a string which is matched against the category
  21452. given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
  21453. file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
  21454. be a substring of the full category name, in order to match multiple
  21455. similar categories), the optional "+" prefix tells libvirt to log stack
  21456. trace for each message matching name, and @code{x} is the minimal level
  21457. where matching messages should be logged:
  21458. @itemize @bullet
  21459. @item
  21460. 1: DEBUG
  21461. @item
  21462. 2: INFO
  21463. @item
  21464. 3: WARNING
  21465. @item
  21466. 4: ERROR
  21467. @end itemize
  21468. Multiple filters can be defined in a single filters statement, they just
  21469. need to be separated by spaces.
  21470. Defaults to @samp{"3:remote 4:event"}.
  21471. @end deftypevr
  21472. @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
  21473. Logging outputs.
  21474. An output is one of the places to save logging information The format
  21475. for an output can be:
  21476. @table @code
  21477. @item x:stderr
  21478. output goes to stderr
  21479. @item x:syslog:name
  21480. use syslog for the output and use the given name as the ident
  21481. @item x:file:file_path
  21482. output to a file, with the given filepath
  21483. @item x:journald
  21484. output to journald logging system
  21485. @end table
  21486. In all case the x prefix is the minimal level, acting as a filter
  21487. @itemize @bullet
  21488. @item
  21489. 1: DEBUG
  21490. @item
  21491. 2: INFO
  21492. @item
  21493. 3: WARNING
  21494. @item
  21495. 4: ERROR
  21496. @end itemize
  21497. Multiple outputs can be defined, they just need to be separated by
  21498. spaces.
  21499. Defaults to @samp{"3:stderr"}.
  21500. @end deftypevr
  21501. @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
  21502. Maximum number of concurrent client connections to allow over all
  21503. sockets combined.
  21504. Defaults to @samp{1024}.
  21505. @end deftypevr
  21506. @deftypevr {@code{virtlog-configuration} parameter} integer max-size
  21507. Maximum file size before rolling over.
  21508. Defaults to @samp{2MB}
  21509. @end deftypevr
  21510. @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
  21511. Maximum number of backup files to keep.
  21512. Defaults to @samp{3}
  21513. @end deftypevr
  21514. @anchor{transparent-emulation-qemu}
  21515. @subsubheading Transparent Emulation with QEMU
  21516. @cindex emulation
  21517. @cindex @code{binfmt_misc}
  21518. @code{qemu-binfmt-service-type} provides support for transparent
  21519. emulation of program binaries built for different architectures---e.g.,
  21520. it allows you to transparently execute an ARMv7 program on an x86_64
  21521. machine. It achieves this by combining the @uref{https://www.qemu.org,
  21522. QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
  21523. This feature only allows you to emulate GNU/Linux on a different
  21524. architecture, but see below for GNU/Hurd support.
  21525. @defvr {Scheme Variable} qemu-binfmt-service-type
  21526. This is the type of the QEMU/binfmt service for transparent emulation.
  21527. Its value must be a @code{qemu-binfmt-configuration} object, which
  21528. specifies the QEMU package to use as well as the architecture we want to
  21529. emulated:
  21530. @lisp
  21531. (service qemu-binfmt-service-type
  21532. (qemu-binfmt-configuration
  21533. (platforms (lookup-qemu-platforms "arm" "aarch64"))))
  21534. @end lisp
  21535. In this example, we enable transparent emulation for the ARM and aarch64
  21536. platforms. Running @code{herd stop qemu-binfmt} turns it off, and
  21537. running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
  21538. herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
  21539. @end defvr
  21540. @deftp {Data Type} qemu-binfmt-configuration
  21541. This is the configuration for the @code{qemu-binfmt} service.
  21542. @table @asis
  21543. @item @code{platforms} (default: @code{'()})
  21544. The list of emulated QEMU platforms. Each item must be a @dfn{platform
  21545. object} as returned by @code{lookup-qemu-platforms} (see below).
  21546. @item @code{guix-support?} (default: @code{#t})
  21547. When it is true, QEMU and all its dependencies are added to the build
  21548. environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
  21549. @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
  21550. handlers to be used within the build environment, which in turn means
  21551. that you can transparently build programs for another architecture.
  21552. For example, let's suppose you're on an x86_64 machine and you have this
  21553. service:
  21554. @lisp
  21555. (service qemu-binfmt-service-type
  21556. (qemu-binfmt-configuration
  21557. (platforms (lookup-qemu-platforms "arm"))
  21558. (guix-support? #t)))
  21559. @end lisp
  21560. You can run:
  21561. @example
  21562. guix build -s armhf-linux inkscape
  21563. @end example
  21564. @noindent
  21565. and it will build Inkscape for ARMv7 @emph{as if it were a native
  21566. build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
  21567. if you'd like to test a package build for an architecture you don't have
  21568. access to!
  21569. When @code{guix-support?} is set to @code{#f}, programs for other
  21570. architectures can still be executed transparently, but invoking commands
  21571. like @command{guix build -s armhf-linux @dots{}} will fail.
  21572. @item @code{qemu} (default: @code{qemu})
  21573. The QEMU package to use.
  21574. @end table
  21575. @end deftp
  21576. @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
  21577. Return the list of QEMU platform objects corresponding to
  21578. @var{platforms}@dots{}. @var{platforms} must be a list of strings
  21579. corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
  21580. @code{"mips64el"}, and so on.
  21581. @end deffn
  21582. @deffn {Scheme Procedure} qemu-platform? @var{obj}
  21583. Return true if @var{obj} is a platform object.
  21584. @end deffn
  21585. @deffn {Scheme Procedure} qemu-platform-name @var{platform}
  21586. Return the name of @var{platform}---a string such as @code{"arm"}.
  21587. @end deffn
  21588. @subsubheading The Hurd in a Virtual Machine
  21589. @cindex @code{hurd}
  21590. @cindex the Hurd
  21591. @cindex childhurd
  21592. Service @code{hurd-vm} provides support for running GNU/Hurd in a
  21593. virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
  21594. to be used on GNU/Linux and the given GNU/Hurd operating system
  21595. configuration is cross-compiled. The virtual machine is a Shepherd
  21596. service that can be referred to by the names @code{hurd-vm} and
  21597. @code{childhurd} and be controlled with commands such as:
  21598. @example
  21599. herd start hurd-vm
  21600. herd stop childhurd
  21601. @end example
  21602. When the service is running, you can view its console by connecting to
  21603. it with a VNC client, for example with:
  21604. @example
  21605. guix environment --ad-hoc tigervnc-client -- \
  21606. vncviewer localhost:5900
  21607. @end example
  21608. The default configuration (see @code{hurd-vm-configuration} below)
  21609. spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
  21610. (the virtual machine emulator) redirects to port 10222 on the host.
  21611. Thus, you can connect over SSH to the childhurd with:
  21612. @example
  21613. ssh root@@localhost -p 10022
  21614. @end example
  21615. The childhurd is volatile and stateless: it starts with a fresh root
  21616. file system every time you restart it. By default though, all the files
  21617. under @file{/etc/childhurd} on the host are copied as is to the root
  21618. file system of the childhurd when it boots. This allows you to
  21619. initialize ``secrets'' inside the VM: SSH host keys, authorized
  21620. substitute keys, and so on---see the explanation of @code{secret-root}
  21621. below.
  21622. @defvr {Scheme Variable} hurd-vm-service-type
  21623. This is the type of the Hurd in a Virtual Machine service. Its value
  21624. must be a @code{hurd-vm-configuration} object, which specifies the
  21625. operating system (@pxref{operating-system Reference}) and the disk size
  21626. for the Hurd Virtual Machine, the QEMU package to use as well as the
  21627. options for running it.
  21628. For example:
  21629. @lisp
  21630. (service hurd-vm-service-type
  21631. (hurd-vm-configuration
  21632. (disk-size (* 5000 (expt 2 20))) ;5G
  21633. (memory-size 1024))) ;1024MiB
  21634. @end lisp
  21635. would create a disk image big enough to build GNU@tie{}Hello, with some
  21636. extra memory.
  21637. @end defvr
  21638. @deftp {Data Type} hurd-vm-configuration
  21639. The data type representing the configuration for
  21640. @code{hurd-vm-service-type}.
  21641. @table @asis
  21642. @item @code{os} (default: @var{%hurd-vm-operating-system})
  21643. The operating system to instantiate. This default is bare-bones with a
  21644. permissive OpenSSH secure shell daemon listening on port 2222
  21645. (@pxref{Networking Services, @code{openssh-service-type}}).
  21646. @item @code{qemu} (default: @code{qemu-minimal})
  21647. The QEMU package to use.
  21648. @item @code{image} (default: @var{hurd-vm-disk-image})
  21649. The procedure used to build the disk-image built from this
  21650. configuration.
  21651. @item @code{disk-size} (default: @code{'guess})
  21652. The size of the disk image.
  21653. @item @code{memory-size} (default: @code{512})
  21654. The memory size of the Virtual Machine in mebibytes.
  21655. @item @code{options} (default: @code{'("--snapshot")})
  21656. The extra options for running QEMU.
  21657. @item @code{id} (default: @code{#f})
  21658. If set, a non-zero positive integer used to parameterize Childhurd
  21659. instances. It is appended to the service's name,
  21660. e.g. @code{childhurd1}.
  21661. @item @code{net-options} (default: @var{hurd-vm-net-options})
  21662. The procedure used to produce the list of QEMU networking options.
  21663. By default, it produces
  21664. @lisp
  21665. '("--device" "rtl8139,netdev=net0"
  21666. "--netdev" "user,id=net0\
  21667. ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
  21668. ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
  21669. ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
  21670. @end lisp
  21671. with forwarded ports:
  21672. @example
  21673. @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
  21674. @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
  21675. @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
  21676. @end example
  21677. @item @code{secret-root} (default: @file{/etc/childhurd})
  21678. The root directory with out-of-band secrets to be installed into the
  21679. childhurd once it runs. Childhurds are volatile which means that on
  21680. every startup, secrets such as the SSH host keys and Guix signing key
  21681. are recreated.
  21682. If the @file{/etc/childhurd} directory does not exist, the
  21683. @code{secret-service} running in the Childhurd will be sent an empty
  21684. list of secrets.
  21685. By default, the service automatically populates @file{/etc/childhurd}
  21686. with the following non-volatile secrets, unless they already exist:
  21687. @example
  21688. /etc/childhurd/etc/guix/acl
  21689. /etc/childhurd/etc/guix/signing-key.pub
  21690. /etc/childhurd/etc/guix/signing-key.sec
  21691. /etc/childhurd/etc/ssh/ssh_host_ed25519_key
  21692. /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
  21693. /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
  21694. /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
  21695. @end example
  21696. These files are automatically sent to the guest Hurd VM when it boots,
  21697. including permissions.
  21698. @cindex childhurd, offloading
  21699. @cindex Hurd, offloading
  21700. Having these files in place means that only a couple of things are
  21701. missing to allow the host to offload @code{i586-gnu} builds to the
  21702. childhurd:
  21703. @enumerate
  21704. @item
  21705. Authorizing the childhurd's key on the host so that the host accepts
  21706. build results coming from the childhurd, which can be done like so:
  21707. @example
  21708. guix archive --authorize < \
  21709. /etc/childhurd/etc/guix/signing-key.pub
  21710. @end example
  21711. @item
  21712. Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
  21713. Offload Setup}).
  21714. @end enumerate
  21715. We're working towards making that happen automatically---get in touch
  21716. with us at @email{guix-devel@@gnu.org} to discuss it!
  21717. @end table
  21718. @end deftp
  21719. Note that by default the VM image is volatile, i.e., once stopped the
  21720. contents are lost. If you want a stateful image instead, override the
  21721. configuration's @code{image} and @code{options} without
  21722. the @code{--snapshot} flag using something along these lines:
  21723. @lisp
  21724. (service hurd-vm-service-type
  21725. (hurd-vm-configuration
  21726. (image (const "/out/of/store/writable/hurd.img"))
  21727. (options '())))
  21728. @end lisp
  21729. @subsubheading Ganeti
  21730. @cindex ganeti
  21731. @quotation Note
  21732. This service is considered experimental. Configuration options may be changed
  21733. in a backwards-incompatible manner, and not all features have been thorougly
  21734. tested. Users of this service are encouraged to share their experience at
  21735. @email{guix-devel@@gnu.org}.
  21736. @end quotation
  21737. Ganeti is a virtual machine management system. It is designed to keep virtual
  21738. machines running on a cluster of servers even in the event of hardware failures,
  21739. and to make maintenance and recovery tasks easy. It consists of multiple
  21740. services which are described later in this section. In addition to the Ganeti
  21741. service, you will need the OpenSSH service (@pxref{Networking Services,
  21742. @code{openssh-service-type}}), and update the @file{/etc/hosts} file
  21743. (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
  21744. and address (or use a DNS server).
  21745. All nodes participating in a Ganeti cluster should have the same Ganeti and
  21746. @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
  21747. cluster node that supports multiple storage backends, and installs the
  21748. @code{debootstrap} and @code{guix} @dfn{OS providers}:
  21749. @lisp
  21750. (use-package-modules virtualization)
  21751. (use-service-modules base ganeti networking ssh)
  21752. (operating-system
  21753. ;; @dots{}
  21754. (host-name "node1")
  21755. (hosts-file (plain-file "hosts" (format #f "
  21756. 127.0.0.1 localhost
  21757. ::1 localhost
  21758. 192.168.1.200 ganeti.example.com
  21759. 192.168.1.201 node1.example.com node1
  21760. 192.168.1.202 node2.example.com node2
  21761. ")))
  21762. ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
  21763. ;; in order to use the "plain", "drbd" and "rbd" storage backends.
  21764. (packages (append (map specification->package
  21765. '("qemu" "lvm2" "drbd-utils" "ceph"
  21766. ;; Add the debootstrap and guix OS providers.
  21767. "ganeti-instance-guix" "ganeti-instance-debootstrap"))
  21768. %base-packages))
  21769. (services
  21770. (append (list (static-networking-service "eth0" "192.168.1.201"
  21771. #:netmask "255.255.255.0"
  21772. #:gateway "192.168.1.254"
  21773. #:name-servers '("192.168.1.252"
  21774. "192.168.1.253"))
  21775. ;; Ganeti uses SSH to communicate between nodes.
  21776. (service openssh-service-type
  21777. (openssh-configuration
  21778. (permit-root-login 'without-password)))
  21779. (service ganeti-service-type
  21780. (ganeti-configuration
  21781. ;; This list specifies allowed file system paths
  21782. ;; for storing virtual machine images.
  21783. (file-storage-paths '("/srv/ganeti/file-storage"))
  21784. ;; This variable configures a single "variant" for
  21785. ;; both Debootstrap and Guix that works with KVM.
  21786. (os %default-ganeti-os))))
  21787. %base-services)))
  21788. @end lisp
  21789. Users are advised to read the
  21790. @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
  21791. administrators guide} to learn about the various cluster options and
  21792. day-to-day operations. There is also a
  21793. @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
  21794. describing how to configure and initialize a small cluster.
  21795. @defvr {Scheme Variable} ganeti-service-type
  21796. This is a service type that includes all the various services that Ganeti
  21797. nodes should run.
  21798. Its value is a @code{ganeti-configuration} object that defines the package
  21799. to use for CLI operations, as well as configuration for the various daemons.
  21800. Allowed file storage paths and available guest operating systems are also
  21801. configured through this data type.
  21802. @end defvr
  21803. @deftp {Data Type} ganeti-configuration
  21804. The @code{ganeti} service takes the following configuration options:
  21805. @table @asis
  21806. @item @code{ganeti} (default: @code{ganeti})
  21807. The @code{ganeti} package to use. It will be installed to the system profile
  21808. and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
  21809. that the value specified here does not affect the other services as each refer
  21810. to a specific @code{ganeti} package (see below).
  21811. @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
  21812. @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
  21813. @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
  21814. @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
  21815. @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
  21816. @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
  21817. @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
  21818. @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
  21819. @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
  21820. @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
  21821. These options control the various daemons and cron jobs that are distributed
  21822. with Ganeti. The possible values for these are described in detail below.
  21823. To override a setting, you must use the configuration type for that service:
  21824. @lisp
  21825. (service ganeti-service-type
  21826. (ganeti-configuration
  21827. (rapi-configuration
  21828. (ganeti-rapi-configuration
  21829. (interface "eth1"))))
  21830. (watcher-configuration
  21831. (ganeti-watcher-configuration
  21832. (rapi-ip "10.0.0.1"))))
  21833. @end lisp
  21834. @item @code{file-storage-paths} (default: @code{'()})
  21835. List of allowed directories for file storage backend.
  21836. @item @code{os} (default: @code{%default-ganeti-os})
  21837. List of @code{<ganeti-os>} records.
  21838. @end table
  21839. In essence @code{ganeti-service-type} is shorthand for declaring each service
  21840. individually:
  21841. @lisp
  21842. (service ganeti-noded-service-type)
  21843. (service ganeti-confd-service-type)
  21844. (service ganeti-wconfd-service-type)
  21845. (service ganeti-luxid-service-type)
  21846. (service ganeti-kvmd-service-type)
  21847. (service ganeti-mond-service-type)
  21848. (service ganeti-metad-service-type)
  21849. (service ganeti-watcher-service-type)
  21850. (service ganeti-cleaner-service-type)
  21851. @end lisp
  21852. Plus a service extension for @code{etc-service-type} that configures the file
  21853. storage backend and OS variants.
  21854. @end deftp
  21855. @deftp {Data Type} ganeti-os
  21856. This data type is suitable for passing to the @code{os} parameter of
  21857. @code{ganeti-configuration}. It takes the following parameters:
  21858. @table @asis
  21859. @item @code{name}
  21860. The name for this OS provider. It is only used to specify where the
  21861. configuration ends up. Setting it to ``debootstrap'' will create
  21862. @file{/etc/ganeti/instance-debootstrap}.
  21863. @item @code{extension}
  21864. The file extension for variants of this OS type. For example
  21865. @file{.conf} or @file{.scm}.
  21866. @item @code{variants} (default: @code{'()})
  21867. List of @code{ganeti-os-variant} objects for this OS.
  21868. @end table
  21869. @end deftp
  21870. @deftp {Data Type} ganeti-os-variant
  21871. This is the data type for a Ganeti OS variant. It takes the following
  21872. parameters:
  21873. @table @asis
  21874. @item @code{name}
  21875. The name of this variant.
  21876. @item @code{configuration}
  21877. A configuration file for this variant.
  21878. @end table
  21879. @end deftp
  21880. @defvr {Scheme Variable} %default-debootstrap-hooks
  21881. This variable contains hooks to configure networking and the GRUB bootloader.
  21882. @end defvr
  21883. @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
  21884. This variable contains a list of packages suitable for a fully-virtualized guest.
  21885. @end defvr
  21886. @deftp {Data Type} debootstrap-configuration
  21887. This data type creates configuration files suitable for the debootstrap OS provider.
  21888. @table @asis
  21889. @item @code{hooks} (default: @code{%default-debootstrap-hooks})
  21890. When not @code{#f}, this must be a G-expression that specifies a directory with
  21891. scripts that will run when the OS is installed. It can also be a list of
  21892. @code{(name . file-like)} pairs. For example:
  21893. @lisp
  21894. `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
  21895. @end lisp
  21896. That will create a directory with one executable named @code{99-hello-world}
  21897. and run it every time this variant is installed. If set to @code{#f}, hooks
  21898. in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
  21899. @item @code{proxy} (default: @code{#f})
  21900. Optional HTTP proxy to use.
  21901. @item @code{mirror} (default: @code{#f})
  21902. The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
  21903. The default varies depending on the distribution.
  21904. @item @code{arch} (default: @code{#f})
  21905. The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
  21906. on an AArch64 host. Default is to use the current system architecture.
  21907. @item @code{suite} (default: @code{"stable"})
  21908. When set, this must be a Debian distribution ``suite'' such as @code{buster}
  21909. or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
  21910. @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
  21911. List of extra packages that will get installed by dpkg in addition
  21912. to the minimal system.
  21913. @item @code{components} (default: @code{#f})
  21914. When set, must be a list of Debian repository ``components''. For example
  21915. @code{'("main" "contrib")}.
  21916. @item @code{generate-cache?} (default: @code{#t})
  21917. Whether to automatically cache the generated debootstrap archive.
  21918. @item @code{clean-cache} (default: @code{14})
  21919. Discard the cache after this amount of days. Use @code{#f} to never
  21920. clear the cache.
  21921. @item @code{partition-style} (default: @code{'msdos})
  21922. The type of partition to create. When set, it must be one of
  21923. @code{'msdos}, @code{'none} or a string.
  21924. @item @code{partition-alignment} (default: @code{2048})
  21925. Alignment of the partition in sectors.
  21926. @end table
  21927. @end deftp
  21928. @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
  21929. This is a helper procedure that creates a @code{ganeti-os-variant} record. It
  21930. takes two parameters: a name and a @code{debootstrap-configuration} object.
  21931. @end deffn
  21932. @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
  21933. This is a helper procedure that creates a @code{ganeti-os} record. It takes
  21934. a list of variants created with @code{debootstrap-variant}.
  21935. @end deffn
  21936. @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
  21937. This is a helper procedure that creates a @code{ganeti-os-variant} record for
  21938. use with the Guix OS provider. It takes a name and a G-expression that returns
  21939. a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
  21940. Guix System configuration.
  21941. @end deffn
  21942. @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
  21943. This is a helper procedure that creates a @code{ganeti-os} record. It
  21944. takes a list of variants produced by @code{guix-variant}.
  21945. @end deffn
  21946. @defvr {Scheme Variable} %default-debootstrap-variants
  21947. This is a convenience variable to make the debootstrap provider work
  21948. ``out of the box'' without users having to declare variants manually. It
  21949. contains a single debootstrap variant with the default configuration:
  21950. @lisp
  21951. (list (debootstrap-variant
  21952. "default"
  21953. (debootstrap-configuration)))
  21954. @end lisp
  21955. @end defvr
  21956. @defvr {Scheme Variable} %default-guix-variants
  21957. This is a convenience variable to make the Guix OS provider work without
  21958. additional configuration. It creates a virtual machine that has an SSH
  21959. server, a serial console, and authorizes the Ganeti hosts SSH keys.
  21960. @lisp
  21961. (list (guix-variant
  21962. "default"
  21963. (file-append ganeti-instance-guix
  21964. "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
  21965. @end lisp
  21966. @end defvr
  21967. Users can implement support for OS providers unbeknownst to Guix by extending
  21968. the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
  21969. For example:
  21970. @lisp
  21971. (ganeti-os
  21972. (name "custom")
  21973. (extension ".conf")
  21974. (variants
  21975. (list (ganeti-os-variant
  21976. (name "foo")
  21977. (configuration (plain-file "bar" "this is fine"))))))
  21978. @end lisp
  21979. That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
  21980. to a file in the store with contents @code{this is fine}. It also creates
  21981. @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
  21982. Obviously this may not work for all OS providers out there. If you find the
  21983. interface limiting, please reach out to @email{guix-devel@@gnu.org}.
  21984. The rest of this section documents the various services that are included by
  21985. @code{ganeti-service-type}.
  21986. @defvr {Scheme Variable} ganeti-noded-service-type
  21987. @command{ganeti-noded} is the daemon responsible for node-specific functions
  21988. within the Ganeti system. The value of this service must be a
  21989. @code{ganeti-noded-configuration} object.
  21990. @end defvr
  21991. @deftp {Data Type} ganeti-noded-configuration
  21992. This is the configuration for the @code{ganeti-noded} service.
  21993. @table @asis
  21994. @item @code{ganeti} (default: @code{ganeti})
  21995. The @code{ganeti} package to use for this service.
  21996. @item @code{port} (default: @code{1811})
  21997. The TCP port on which the node daemon listens for network requests.
  21998. @item @code{address} (default: @code{"0.0.0.0"})
  21999. The network address that the daemon will bind to. The default address means
  22000. bind to all available addresses.
  22001. @item @code{interface} (default: @code{#f})
  22002. When this is set, it must be a specific network interface (e.g.@: @code{eth0})
  22003. that the daemon will bind to.
  22004. @item @code{max-clients} (default: @code{20})
  22005. This sets a limit on the maximum number of simultaneous client connections
  22006. that the daemon will handle. Connections above this count are accepted, but
  22007. no responses will be sent until enough connections have closed.
  22008. @item @code{ssl?} (default: @code{#t})
  22009. Whether to use SSL/TLS to encrypt network communications. The certificate
  22010. is automatically provisioned by the cluster and can be rotated with
  22011. @command{gnt-cluster renew-crypto}.
  22012. @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
  22013. This can be used to provide a specific encryption key for TLS communications.
  22014. @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
  22015. This can be used to provide a specific certificate for TLS communications.
  22016. @item @code{debug?} (default: @code{#f})
  22017. When true, the daemon performs additional logging for debugging purposes.
  22018. Note that this will leak encryption details to the log files, use with caution.
  22019. @end table
  22020. @end deftp
  22021. @defvr {Scheme Variable} ganeti-confd-service-type
  22022. @command{ganeti-confd} answers queries related to the configuration of a
  22023. Ganeti cluster. The purpose of this daemon is to have a highly available
  22024. and fast way to query cluster configuration values. It is automatically
  22025. active on all @dfn{master candidates}. The value of this service must be a
  22026. @code{ganeti-confd-configuration} object.
  22027. @end defvr
  22028. @deftp {Data Type} ganeti-confd-configuration
  22029. This is the configuration for the @code{ganeti-confd} service.
  22030. @table @asis
  22031. @item @code{ganeti} (default: @code{ganeti})
  22032. The @code{ganeti} package to use for this service.
  22033. @item @code{port} (default: @code{1814})
  22034. The UDP port on which to listen for network requests.
  22035. @item @code{address} (default: @code{"0.0.0.0"})
  22036. Network address that the daemon will bind to.
  22037. @item @code{debug?} (default: @code{#f})
  22038. When true, the daemon performs additional logging for debugging purposes.
  22039. @end table
  22040. @end deftp
  22041. @defvr {Scheme Variable} ganeti-wconfd-service-type
  22042. @command{ganeti-wconfd} is the daemon that has authoritative knowledge
  22043. about the cluster configuration and is the only entity that can accept
  22044. changes to it. All jobs that need to modify the configuration will do so
  22045. by sending appropriate requests to this daemon. It only runs on the
  22046. @dfn{master node} and will automatically disable itself on other nodes.
  22047. The value of this service must be a
  22048. @code{ganeti-wconfd-configuration} object.
  22049. @end defvr
  22050. @deftp {Data Type} ganeti-wconfd-configuration
  22051. This is the configuration for the @code{ganeti-wconfd} service.
  22052. @table @asis
  22053. @item @code{ganeti} (default: @code{ganeti})
  22054. The @code{ganeti} package to use for this service.
  22055. @item @code{no-voting?} (default: @code{#f})
  22056. The daemon will refuse to start if the majority of cluster nodes does not
  22057. agree that it is running on the master node. Set to @code{#t} to start
  22058. even if a quorum can not be reached (dangerous, use with caution).
  22059. @item @code{debug?} (default: @code{#f})
  22060. When true, the daemon performs additional logging for debugging purposes.
  22061. @end table
  22062. @end deftp
  22063. @defvr {Scheme Variable} ganeti-luxid-service-type
  22064. @command{ganeti-luxid} is a daemon used to answer queries related to the
  22065. configuration and the current live state of a Ganeti cluster. Additionally,
  22066. it is the authoritative daemon for the Ganeti job queue. Jobs can be
  22067. submitted via this daemon and it schedules and starts them.
  22068. It takes a @code{ganeti-luxid-configuration} object.
  22069. @end defvr
  22070. @deftp {Data Type} ganeti-luxid-configuration
  22071. This is the configuration for the @code{ganeti-wconfd} service.
  22072. @table @asis
  22073. @item @code{ganeti} (default: @code{ganeti})
  22074. The @code{ganeti} package to use for this service.
  22075. @item @code{no-voting?} (default: @code{#f})
  22076. The daemon will refuse to start if it cannot verify that the majority of
  22077. cluster nodes believes that it is running on the master node. Set to
  22078. @code{#t} to ignore such checks and start anyway (this can be dangerous).
  22079. @item @code{debug?} (default: @code{#f})
  22080. When true, the daemon performs additional logging for debugging purposes.
  22081. @end table
  22082. @end deftp
  22083. @defvr {Scheme Variable} ganeti-rapi-service-type
  22084. @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
  22085. the master node and can be used to perform cluster actions programmatically
  22086. via a JSON-based RPC protocol.
  22087. Most query operations are allowed without authentication (unless
  22088. @var{require-authentication?} is set), whereas write operations require
  22089. explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
  22090. the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
  22091. API documentation} for more information.
  22092. The value of this service must be a @code{ganeti-rapi-configuration} object.
  22093. @end defvr
  22094. @deftp {Data Type} ganeti-rapi-configuration
  22095. This is the configuration for the @code{ganeti-rapi} service.
  22096. @table @asis
  22097. @item @code{ganeti} (default: @code{ganeti})
  22098. The @code{ganeti} package to use for this service.
  22099. @item @code{require-authentication?} (default: @code{#f})
  22100. Whether to require authentication even for read-only operations.
  22101. @item @code{port} (default: @code{5080})
  22102. The TCP port on which to listen to API requests.
  22103. @item @code{address} (default: @code{"0.0.0.0"})
  22104. The network address that the service will bind to. By default it listens
  22105. on all configured addresses.
  22106. @item @code{interface} (default: @code{#f})
  22107. When set, it must specify a specific network interface such as @code{eth0}
  22108. that the daemon will bind to.
  22109. @item @code{max-clients} (default: @code{20})
  22110. The maximum number of simultaneous client requests to handle. Further
  22111. connections are allowed, but no responses are sent until enough connections
  22112. have closed.
  22113. @item @code{ssl?} (default: @code{#t})
  22114. Whether to use SSL/TLS encryption on the RAPI port.
  22115. @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
  22116. This can be used to provide a specific encryption key for TLS communications.
  22117. @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
  22118. This can be used to provide a specific certificate for TLS communications.
  22119. @item @code{debug?} (default: @code{#f})
  22120. When true, the daemon performs additional logging for debugging purposes.
  22121. Note that this will leak encryption details to the log files, use with caution.
  22122. @end table
  22123. @end deftp
  22124. @defvr {Scheme Variable} ganeti-kvmd-service-type
  22125. @command{ganeti-kvmd} is responsible for determining whether a given KVM
  22126. instance was shut down by an administrator or a user. Normally Ganeti will
  22127. restart an instance that was not stopped through Ganeti itself. If the
  22128. cluster option @code{user_shutdown} is true, this daemon monitors the
  22129. @code{QMP} socket provided by QEMU and listens for shutdown events, and
  22130. marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
  22131. it shuts down gracefully by itself.
  22132. It takes a @code{ganeti-kvmd-configuration} object.
  22133. @end defvr
  22134. @deftp {Data Type} ganeti-kvmd-configuration
  22135. @table @asis
  22136. @item @code{ganeti} (default: @code{ganeti})
  22137. The @code{ganeti} package to use for this service.
  22138. @item @code{debug?} (default: @code{#f})
  22139. When true, the daemon performs additional logging for debugging purposes.
  22140. @end table
  22141. @end deftp
  22142. @defvr {Scheme Variable} ganeti-mond-service-type
  22143. @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
  22144. functionality. It is responsible for running data collectors and publish the
  22145. collected information through a HTTP interface.
  22146. It takes a @code{ganeti-mond-configuration} object.
  22147. @end defvr
  22148. @deftp {Data Type} ganeti-mond-configuration
  22149. @table @asis
  22150. @item @code{ganeti} (default: @code{ganeti})
  22151. The @code{ganeti} package to use for this service.
  22152. @item @code{port} (default: @code{1815})
  22153. The port on which the daemon will listen.
  22154. @item @code{address} (default: @code{"0.0.0.0"})
  22155. The network address that the daemon will bind to. By default it binds to all
  22156. available interfaces.
  22157. @item @code{debug?} (default: @code{#f})
  22158. When true, the daemon performs additional logging for debugging purposes.
  22159. @end table
  22160. @end deftp
  22161. @defvr {Scheme Variable} ganeti-metad-service-type
  22162. @command{ganeti-metad} is an optional daemon that can be used to provide
  22163. information about the cluster to instances or OS install scripts.
  22164. It takes a @code{ganeti-metad-configuration} object.
  22165. @end defvr
  22166. @deftp {Data Type} ganeti-metad-configuration
  22167. @table @asis
  22168. @item @code{ganeti} (default: @code{ganeti})
  22169. The @code{ganeti} package to use for this service.
  22170. @item @code{port} (default: @code{80})
  22171. The port on which the daemon will listen.
  22172. @item @code{address} (default: @code{#f})
  22173. If set, the daemon will bind to this address only. If left unset, the behavior
  22174. depends on the cluster configuration.
  22175. @item @code{debug?} (default: @code{#f})
  22176. When true, the daemon performs additional logging for debugging purposes.
  22177. @end table
  22178. @end deftp
  22179. @defvr {Scheme Variable} ganeti-watcher-service-type
  22180. @command{ganeti-watcher} is a script designed to run periodically and ensure
  22181. the health of a cluster. It will automatically restart instances that have
  22182. stopped without Ganeti's consent, and repairs DRBD links in case a node has
  22183. rebooted. It also archives old cluster jobs and restarts Ganeti daemons
  22184. that are not running. If the cluster parameter @code{ensure_node_health}
  22185. is set, the watcher will also shutdown instances and DRBD devices if the
  22186. node it is running on is declared offline by known master candidates.
  22187. It can be paused on all nodes with @command{gnt-cluster watcher pause}.
  22188. The service takes a @code{ganeti-watcher-configuration} object.
  22189. @end defvr
  22190. @deftp {Data Type} ganeti-watcher-configuration
  22191. @table @asis
  22192. @item @code{ganeti} (default: @code{ganeti})
  22193. The @code{ganeti} package to use for this service.
  22194. @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
  22195. How often to run the script. The default is every five minutes.
  22196. @item @code{rapi-ip} (default: @code{#f})
  22197. This option needs to be specified only if the RAPI daemon is configured to use
  22198. a particular interface or address. By default the cluster address is used.
  22199. @item @code{job-age} (default: @code{(* 6 3600)})
  22200. Archive cluster jobs older than this age, specified in seconds. The default
  22201. is 6 hours. This keeps @command{gnt-job list} manageable.
  22202. @item @code{verify-disks?} (default: @code{#t})
  22203. If this is @code{#f}, the watcher will not try to repair broken DRBD links
  22204. automatically. Administrators will need to use @command{gnt-cluster verify-disks}
  22205. manually instead.
  22206. @item @code{debug?} (default: @code{#f})
  22207. When @code{#t}, the script performs additional logging for debugging purposes.
  22208. @end table
  22209. @end deftp
  22210. @defvr {Scheme Variable} ganeti-cleaner-service-type
  22211. @command{ganeti-cleaner} is a script designed to run periodically and remove
  22212. old files from the cluster. This service type controls two @dfn{cron jobs}:
  22213. one intended for the master node that permanently purges old cluster jobs,
  22214. and one intended for every node that removes expired X509 certificates, keys,
  22215. and outdated @command{ganeti-watcher} information. Like all Ganeti services,
  22216. it is safe to include even on non-master nodes as it will disable itself as
  22217. necessary.
  22218. It takes a @code{ganeti-cleaner-configuration} object.
  22219. @end defvr
  22220. @deftp {Data Type} ganeti-cleaner-configuration
  22221. @table @asis
  22222. @item @code{ganeti} (default: @code{ganeti})
  22223. The @code{ganeti} package to use for the @command{gnt-cleaner} command.
  22224. @item @code{master-schedule} (default: @code{"45 1 * * *"})
  22225. How often to run the master cleaning job. The default is once per day, at
  22226. 01:45:00.
  22227. @item @code{node-schedule} (default: @code{"45 2 * * *"})
  22228. How often to run the node cleaning job. The default is once per day, at
  22229. 02:45:00.
  22230. @end table
  22231. @end deftp
  22232. @node Version Control Services
  22233. @subsection Version Control Services
  22234. The @code{(gnu services version-control)} module provides a service to
  22235. allow remote access to local Git repositories. There are three options:
  22236. the @code{git-daemon-service}, which provides access to repositories via
  22237. the @code{git://} unsecured TCP-based protocol, extending the
  22238. @code{nginx} web server to proxy some requests to
  22239. @code{git-http-backend}, or providing a web interface with
  22240. @code{cgit-service-type}.
  22241. @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
  22242. Return a service that runs @command{git daemon}, a simple TCP server to
  22243. expose repositories over the Git protocol for anonymous access.
  22244. The optional @var{config} argument should be a
  22245. @code{<git-daemon-configuration>} object, by default it allows read-only
  22246. access to exported@footnote{By creating the magic file
  22247. @file{git-daemon-export-ok} in the repository directory.} repositories under
  22248. @file{/srv/git}.
  22249. @end deffn
  22250. @deftp {Data Type} git-daemon-configuration
  22251. Data type representing the configuration for @code{git-daemon-service}.
  22252. @table @asis
  22253. @item @code{package} (default: @code{git})
  22254. Package object of the Git distributed version control system.
  22255. @item @code{export-all?} (default: @code{#f})
  22256. Whether to allow access for all Git repositories, even if they do not
  22257. have the @file{git-daemon-export-ok} file.
  22258. @item @code{base-path} (default: @file{/srv/git})
  22259. Whether to remap all the path requests as relative to the given path.
  22260. If you run @command{git daemon} with @code{(base-path "/srv/git")} on
  22261. @samp{example.com}, then if you later try to pull
  22262. @indicateurl{git://example.com/hello.git}, git daemon will interpret the
  22263. path as @file{/srv/git/hello.git}.
  22264. @item @code{user-path} (default: @code{#f})
  22265. Whether to allow @code{~user} notation to be used in requests. When
  22266. specified with empty string, requests to
  22267. @indicateurl{git://host/~alice/foo} is taken as a request to access
  22268. @code{foo} repository in the home directory of user @code{alice}. If
  22269. @code{(user-path "@var{path}")} is specified, the same request is taken
  22270. as a request to access @file{@var{path}/foo} repository in the home
  22271. directory of user @code{alice}.
  22272. @item @code{listen} (default: @code{'()})
  22273. Whether to listen on specific IP addresses or hostnames, defaults to
  22274. all.
  22275. @item @code{port} (default: @code{#f})
  22276. Whether to listen on an alternative port, which defaults to 9418.
  22277. @item @code{whitelist} (default: @code{'()})
  22278. If not empty, only allow access to this list of directories.
  22279. @item @code{extra-options} (default: @code{'()})
  22280. Extra options will be passed to @command{git daemon}, please run
  22281. @command{man git-daemon} for more information.
  22282. @end table
  22283. @end deftp
  22284. The @code{git://} protocol lacks authentication. When you pull from a
  22285. repository fetched via @code{git://}, you don't know whether the data you
  22286. receive was modified or is even coming from the specified host, and your
  22287. connection is subject to eavesdropping. It's better to use an authenticated
  22288. and encrypted transport, such as @code{https}. Although Git allows you
  22289. to serve repositories using unsophisticated file-based web servers,
  22290. there is a faster protocol implemented by the @code{git-http-backend}
  22291. program. This program is the back-end of a proper Git web service. It
  22292. is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
  22293. on running the necessary @code{fcgiwrap} daemon.
  22294. Guix has a separate configuration data type for serving Git repositories
  22295. over HTTP.
  22296. @deftp {Data Type} git-http-configuration
  22297. Data type representing the configuration for a future
  22298. @code{git-http-service-type}; can currently be used to configure Nginx
  22299. through @code{git-http-nginx-location-configuration}.
  22300. @table @asis
  22301. @item @code{package} (default: @var{git})
  22302. Package object of the Git distributed version control system.
  22303. @item @code{git-root} (default: @file{/srv/git})
  22304. Directory containing the Git repositories to expose to the world.
  22305. @item @code{export-all?} (default: @code{#f})
  22306. Whether to expose access for all Git repositories in @var{git-root},
  22307. even if they do not have the @file{git-daemon-export-ok} file.
  22308. @item @code{uri-path} (default: @samp{/git/})
  22309. Path prefix for Git access. With the default @samp{/git/} prefix, this
  22310. will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
  22311. @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
  22312. with this prefix are not passed on to this Git instance.
  22313. @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
  22314. The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
  22315. Services}.
  22316. @end table
  22317. @end deftp
  22318. There is no @code{git-http-service-type}, currently; instead you can
  22319. create an @code{nginx-location-configuration} from a
  22320. @code{git-http-configuration} and then add that location to a web
  22321. server.
  22322. @deffn {Scheme Procedure} git-http-nginx-location-configuration @
  22323. [config=(git-http-configuration)]
  22324. Compute an @code{nginx-location-configuration} that corresponds to the
  22325. given Git http configuration. An example nginx service definition to
  22326. serve the default @file{/srv/git} over HTTPS might be:
  22327. @lisp
  22328. (service nginx-service-type
  22329. (nginx-configuration
  22330. (server-blocks
  22331. (list
  22332. (nginx-server-configuration
  22333. (listen '("443 ssl"))
  22334. (server-name "git.my-host.org")
  22335. (ssl-certificate
  22336. "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
  22337. (ssl-certificate-key
  22338. "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
  22339. (locations
  22340. (list
  22341. (git-http-nginx-location-configuration
  22342. (git-http-configuration (uri-path "/"))))))))))
  22343. @end lisp
  22344. This example assumes that you are using Let's Encrypt to get your TLS
  22345. certificate. @xref{Certificate Services}. The default @code{certbot}
  22346. service will redirect all HTTP traffic on @code{git.my-host.org} to
  22347. HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
  22348. system services. @xref{Web Services}.
  22349. @end deffn
  22350. @subsubheading Cgit Service
  22351. @cindex Cgit service
  22352. @cindex Git, web interface
  22353. @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
  22354. repositories written in C.
  22355. The following example will configure the service with default values.
  22356. By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
  22357. @lisp
  22358. (service cgit-service-type)
  22359. @end lisp
  22360. The @code{file-object} type designates either a file-like object
  22361. (@pxref{G-Expressions, file-like objects}) or a string.
  22362. @c %start of fragment
  22363. Available @code{cgit-configuration} fields are:
  22364. @deftypevr {@code{cgit-configuration} parameter} package package
  22365. The CGIT package.
  22366. @end deftypevr
  22367. @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
  22368. NGINX configuration.
  22369. @end deftypevr
  22370. @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
  22371. Specifies a command which will be invoked to format the content of about
  22372. pages (both top-level and for each repository).
  22373. Defaults to @samp{""}.
  22374. @end deftypevr
  22375. @deftypevr {@code{cgit-configuration} parameter} string agefile
  22376. Specifies a path, relative to each repository path, which can be used to
  22377. specify the date and time of the youngest commit in the repository.
  22378. Defaults to @samp{""}.
  22379. @end deftypevr
  22380. @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
  22381. Specifies a command that will be invoked for authenticating repository
  22382. access.
  22383. Defaults to @samp{""}.
  22384. @end deftypevr
  22385. @deftypevr {@code{cgit-configuration} parameter} string branch-sort
  22386. Flag which, when set to @samp{age}, enables date ordering in the branch
  22387. ref list, and when set @samp{name} enables ordering by branch name.
  22388. Defaults to @samp{"name"}.
  22389. @end deftypevr
  22390. @deftypevr {@code{cgit-configuration} parameter} string cache-root
  22391. Path used to store the cgit cache entries.
  22392. Defaults to @samp{"/var/cache/cgit"}.
  22393. @end deftypevr
  22394. @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
  22395. Number which specifies the time-to-live, in minutes, for the cached
  22396. version of repository pages accessed with a fixed SHA1.
  22397. Defaults to @samp{-1}.
  22398. @end deftypevr
  22399. @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
  22400. Number which specifies the time-to-live, in minutes, for the cached
  22401. version of repository pages accessed without a fixed SHA1.
  22402. Defaults to @samp{5}.
  22403. @end deftypevr
  22404. @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
  22405. Number which specifies the time-to-live, in minutes, for the cached
  22406. version of the repository summary page.
  22407. Defaults to @samp{5}.
  22408. @end deftypevr
  22409. @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
  22410. Number which specifies the time-to-live, in minutes, for the cached
  22411. version of the repository index page.
  22412. Defaults to @samp{5}.
  22413. @end deftypevr
  22414. @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
  22415. Number which specifies the time-to-live, in minutes, for the result of
  22416. scanning a path for Git repositories.
  22417. Defaults to @samp{15}.
  22418. @end deftypevr
  22419. @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
  22420. Number which specifies the time-to-live, in minutes, for the cached
  22421. version of the repository about page.
  22422. Defaults to @samp{15}.
  22423. @end deftypevr
  22424. @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
  22425. Number which specifies the time-to-live, in minutes, for the cached
  22426. version of snapshots.
  22427. Defaults to @samp{5}.
  22428. @end deftypevr
  22429. @deftypevr {@code{cgit-configuration} parameter} integer cache-size
  22430. The maximum number of entries in the cgit cache. When set to @samp{0},
  22431. caching is disabled.
  22432. Defaults to @samp{0}.
  22433. @end deftypevr
  22434. @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
  22435. Sort items in the repo list case sensitively.
  22436. Defaults to @samp{#t}.
  22437. @end deftypevr
  22438. @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
  22439. List of common prefixes which, when combined with a repository URL,
  22440. generates valid clone URLs for the repository.
  22441. Defaults to @samp{()}.
  22442. @end deftypevr
  22443. @deftypevr {@code{cgit-configuration} parameter} list clone-url
  22444. List of @code{clone-url} templates.
  22445. Defaults to @samp{()}.
  22446. @end deftypevr
  22447. @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
  22448. Command which will be invoked to format commit messages.
  22449. Defaults to @samp{""}.
  22450. @end deftypevr
  22451. @deftypevr {@code{cgit-configuration} parameter} string commit-sort
  22452. Flag which, when set to @samp{date}, enables strict date ordering in the
  22453. commit log, and when set to @samp{topo} enables strict topological
  22454. ordering.
  22455. Defaults to @samp{"git log"}.
  22456. @end deftypevr
  22457. @deftypevr {@code{cgit-configuration} parameter} file-object css
  22458. URL which specifies the css document to include in all cgit pages.
  22459. Defaults to @samp{"/share/cgit/cgit.css"}.
  22460. @end deftypevr
  22461. @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
  22462. Specifies a command which will be invoked to format names and email
  22463. address of committers, authors, and taggers, as represented in various
  22464. places throughout the cgit interface.
  22465. Defaults to @samp{""}.
  22466. @end deftypevr
  22467. @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
  22468. Flag which, when set to @samp{#t}, will make cgit generate a HTML
  22469. fragment suitable for embedding in other HTML pages.
  22470. Defaults to @samp{#f}.
  22471. @end deftypevr
  22472. @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
  22473. Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
  22474. commit history graph to the left of the commit messages in the
  22475. repository log page.
  22476. Defaults to @samp{#f}.
  22477. @end deftypevr
  22478. @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
  22479. Flag which, when set to @samp{#t}, allows all filter settings to be
  22480. overridden in repository-specific cgitrc files.
  22481. Defaults to @samp{#f}.
  22482. @end deftypevr
  22483. @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
  22484. Flag which, when set to @samp{#t}, allows users to follow a file in the
  22485. log view.
  22486. Defaults to @samp{#f}.
  22487. @end deftypevr
  22488. @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
  22489. If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
  22490. clones.
  22491. Defaults to @samp{#t}.
  22492. @end deftypevr
  22493. @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
  22494. Flag which, when set to @samp{#t}, will make cgit generate extra links
  22495. "summary", "commit", "tree" for each repo in the repository index.
  22496. Defaults to @samp{#f}.
  22497. @end deftypevr
  22498. @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
  22499. Flag which, when set to @samp{#t}, will make cgit display the owner of
  22500. each repo in the repository index.
  22501. Defaults to @samp{#t}.
  22502. @end deftypevr
  22503. @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
  22504. Flag which, when set to @samp{#t}, will make cgit print the number of
  22505. modified files for each commit on the repository log page.
  22506. Defaults to @samp{#f}.
  22507. @end deftypevr
  22508. @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
  22509. Flag which, when set to @samp{#t}, will make cgit print the number of
  22510. added and removed lines for each commit on the repository log page.
  22511. Defaults to @samp{#f}.
  22512. @end deftypevr
  22513. @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
  22514. Flag which, when set to @code{#t}, will make cgit display remote
  22515. branches in the summary and refs views.
  22516. Defaults to @samp{#f}.
  22517. @end deftypevr
  22518. @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
  22519. Flag which, when set to @code{1}, will make cgit use the subject of the
  22520. parent commit as link text when generating links to parent commits in
  22521. commit view.
  22522. Defaults to @samp{#f}.
  22523. @end deftypevr
  22524. @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
  22525. Flag which, when set to @samp{#t}, will make cgit use the subject of the
  22526. parent commit as link text when generating links to parent commits in
  22527. commit view.
  22528. Defaults to @samp{#f}.
  22529. @end deftypevr
  22530. @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
  22531. Flag which, when set to @samp{#t}, will make cgit generate linenumber
  22532. links for plaintext blobs printed in the tree view.
  22533. Defaults to @samp{#t}.
  22534. @end deftypevr
  22535. @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
  22536. Flag which, when set to @samp{#f}, will allow cgit to use Git config to
  22537. set any repo specific settings.
  22538. Defaults to @samp{#f}.
  22539. @end deftypevr
  22540. @deftypevr {@code{cgit-configuration} parameter} file-object favicon
  22541. URL used as link to a shortcut icon for cgit.
  22542. Defaults to @samp{"/favicon.ico"}.
  22543. @end deftypevr
  22544. @deftypevr {@code{cgit-configuration} parameter} string footer
  22545. The content of the file specified with this option will be included
  22546. verbatim at the bottom of all pages (i.e.@: it replaces the standard
  22547. "generated by..."@: message).
  22548. Defaults to @samp{""}.
  22549. @end deftypevr
  22550. @deftypevr {@code{cgit-configuration} parameter} string head-include
  22551. The content of the file specified with this option will be included
  22552. verbatim in the HTML HEAD section on all pages.
  22553. Defaults to @samp{""}.
  22554. @end deftypevr
  22555. @deftypevr {@code{cgit-configuration} parameter} string header
  22556. The content of the file specified with this option will be included
  22557. verbatim at the top of all pages.
  22558. Defaults to @samp{""}.
  22559. @end deftypevr
  22560. @deftypevr {@code{cgit-configuration} parameter} file-object include
  22561. Name of a configfile to include before the rest of the current config-
  22562. file is parsed.
  22563. Defaults to @samp{""}.
  22564. @end deftypevr
  22565. @deftypevr {@code{cgit-configuration} parameter} string index-header
  22566. The content of the file specified with this option will be included
  22567. verbatim above the repository index.
  22568. Defaults to @samp{""}.
  22569. @end deftypevr
  22570. @deftypevr {@code{cgit-configuration} parameter} string index-info
  22571. The content of the file specified with this option will be included
  22572. verbatim below the heading on the repository index page.
  22573. Defaults to @samp{""}.
  22574. @end deftypevr
  22575. @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
  22576. Flag which, if set to @samp{#t}, makes cgit print commit and tag times
  22577. in the servers timezone.
  22578. Defaults to @samp{#f}.
  22579. @end deftypevr
  22580. @deftypevr {@code{cgit-configuration} parameter} file-object logo
  22581. URL which specifies the source of an image which will be used as a logo
  22582. on all cgit pages.
  22583. Defaults to @samp{"/share/cgit/cgit.png"}.
  22584. @end deftypevr
  22585. @deftypevr {@code{cgit-configuration} parameter} string logo-link
  22586. URL loaded when clicking on the cgit logo image.
  22587. Defaults to @samp{""}.
  22588. @end deftypevr
  22589. @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
  22590. Command which will be invoked to format the Owner column of the main
  22591. page.
  22592. Defaults to @samp{""}.
  22593. @end deftypevr
  22594. @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
  22595. Number of items to display in atom feeds view.
  22596. Defaults to @samp{10}.
  22597. @end deftypevr
  22598. @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
  22599. Number of entries to list per page in "log" view.
  22600. Defaults to @samp{50}.
  22601. @end deftypevr
  22602. @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
  22603. Number of commit message characters to display in "log" view.
  22604. Defaults to @samp{80}.
  22605. @end deftypevr
  22606. @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
  22607. Specifies the number of entries to list per page on the repository index
  22608. page.
  22609. Defaults to @samp{50}.
  22610. @end deftypevr
  22611. @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
  22612. Specifies the maximum number of repo description characters to display
  22613. on the repository index page.
  22614. Defaults to @samp{80}.
  22615. @end deftypevr
  22616. @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
  22617. Specifies the maximum size of a blob to display HTML for in KBytes.
  22618. Defaults to @samp{0}.
  22619. @end deftypevr
  22620. @deftypevr {@code{cgit-configuration} parameter} string max-stats
  22621. Maximum statistics period. Valid values are @samp{week},@samp{month},
  22622. @samp{quarter} and @samp{year}.
  22623. Defaults to @samp{""}.
  22624. @end deftypevr
  22625. @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
  22626. Mimetype for the specified filename extension.
  22627. Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
  22628. "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
  22629. "image/png") (svg "image/svg+xml"))}.
  22630. @end deftypevr
  22631. @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
  22632. Specifies the file to use for automatic mimetype lookup.
  22633. Defaults to @samp{""}.
  22634. @end deftypevr
  22635. @deftypevr {@code{cgit-configuration} parameter} string module-link
  22636. Text which will be used as the formatstring for a hyperlink when a
  22637. submodule is printed in a directory listing.
  22638. Defaults to @samp{""}.
  22639. @end deftypevr
  22640. @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
  22641. If set to the value @samp{#t} caching will be disabled.
  22642. Defaults to @samp{#f}.
  22643. @end deftypevr
  22644. @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
  22645. If set to @samp{#t} showing full author email addresses will be
  22646. disabled.
  22647. Defaults to @samp{#f}.
  22648. @end deftypevr
  22649. @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
  22650. Flag which, when set to @samp{#t}, will make cgit omit the standard
  22651. header on all pages.
  22652. Defaults to @samp{#f}.
  22653. @end deftypevr
  22654. @deftypevr {@code{cgit-configuration} parameter} project-list project-list
  22655. A list of subdirectories inside of @code{repository-directory}, relative
  22656. to it, that should loaded as Git repositories. An empty list means that
  22657. all subdirectories will be loaded.
  22658. Defaults to @samp{()}.
  22659. @end deftypevr
  22660. @deftypevr {@code{cgit-configuration} parameter} file-object readme
  22661. Text which will be used as default value for @code{cgit-repo-readme}.
  22662. Defaults to @samp{""}.
  22663. @end deftypevr
  22664. @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
  22665. If set to @code{#t} and @code{repository-directory} is enabled, if any
  22666. repositories are found with a suffix of @code{.git}, this suffix will be
  22667. removed for the URL and name.
  22668. Defaults to @samp{#f}.
  22669. @end deftypevr
  22670. @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
  22671. Maximum number of files to consider when detecting renames.
  22672. Defaults to @samp{-1}.
  22673. @end deftypevr
  22674. @deftypevr {@code{cgit-configuration} parameter} string repository-sort
  22675. The way in which repositories in each section are sorted.
  22676. Defaults to @samp{""}.
  22677. @end deftypevr
  22678. @deftypevr {@code{cgit-configuration} parameter} robots-list robots
  22679. Text used as content for the @code{robots} meta-tag.
  22680. Defaults to @samp{("noindex" "nofollow")}.
  22681. @end deftypevr
  22682. @deftypevr {@code{cgit-configuration} parameter} string root-desc
  22683. Text printed below the heading on the repository index page.
  22684. Defaults to @samp{"a fast webinterface for the git dscm"}.
  22685. @end deftypevr
  22686. @deftypevr {@code{cgit-configuration} parameter} string root-readme
  22687. The content of the file specified with this option will be included
  22688. verbatim below the ``about'' link on the repository index page.
  22689. Defaults to @samp{""}.
  22690. @end deftypevr
  22691. @deftypevr {@code{cgit-configuration} parameter} string root-title
  22692. Text printed as heading on the repository index page.
  22693. Defaults to @samp{""}.
  22694. @end deftypevr
  22695. @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
  22696. If set to @samp{#t} and repository-directory is enabled,
  22697. repository-directory will recurse into directories whose name starts
  22698. with a period. Otherwise, repository-directory will stay away from such
  22699. directories, considered as ``hidden''. Note that this does not apply to
  22700. the @file{.git} directory in non-bare repos.
  22701. Defaults to @samp{#f}.
  22702. @end deftypevr
  22703. @deftypevr {@code{cgit-configuration} parameter} list snapshots
  22704. Text which specifies the default set of snapshot formats that cgit
  22705. generates links for.
  22706. Defaults to @samp{()}.
  22707. @end deftypevr
  22708. @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
  22709. Name of the directory to scan for repositories (represents
  22710. @code{scan-path}).
  22711. Defaults to @samp{"/srv/git"}.
  22712. @end deftypevr
  22713. @deftypevr {@code{cgit-configuration} parameter} string section
  22714. The name of the current repository section - all repositories defined
  22715. after this option will inherit the current section name.
  22716. Defaults to @samp{""}.
  22717. @end deftypevr
  22718. @deftypevr {@code{cgit-configuration} parameter} string section-sort
  22719. Flag which, when set to @samp{1}, will sort the sections on the
  22720. repository listing by name.
  22721. Defaults to @samp{""}.
  22722. @end deftypevr
  22723. @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
  22724. A number which, if defined prior to repository-directory, specifies how
  22725. many path elements from each repo path to use as a default section name.
  22726. Defaults to @samp{0}.
  22727. @end deftypevr
  22728. @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
  22729. If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
  22730. default.
  22731. Defaults to @samp{#f}.
  22732. @end deftypevr
  22733. @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
  22734. Specifies a command which will be invoked to format plaintext blobs in
  22735. the tree view.
  22736. Defaults to @samp{""}.
  22737. @end deftypevr
  22738. @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
  22739. Specifies the number of branches to display in the repository ``summary''
  22740. view.
  22741. Defaults to @samp{10}.
  22742. @end deftypevr
  22743. @deftypevr {@code{cgit-configuration} parameter} integer summary-log
  22744. Specifies the number of log entries to display in the repository
  22745. ``summary'' view.
  22746. Defaults to @samp{10}.
  22747. @end deftypevr
  22748. @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
  22749. Specifies the number of tags to display in the repository ``summary''
  22750. view.
  22751. Defaults to @samp{10}.
  22752. @end deftypevr
  22753. @deftypevr {@code{cgit-configuration} parameter} string strict-export
  22754. Filename which, if specified, needs to be present within the repository
  22755. for cgit to allow access to that repository.
  22756. Defaults to @samp{""}.
  22757. @end deftypevr
  22758. @deftypevr {@code{cgit-configuration} parameter} string virtual-root
  22759. URL which, if specified, will be used as root for all cgit links.
  22760. Defaults to @samp{"/"}.
  22761. @end deftypevr
  22762. @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
  22763. A list of @dfn{cgit-repo} records to use with config.
  22764. Defaults to @samp{()}.
  22765. Available @code{repository-cgit-configuration} fields are:
  22766. @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
  22767. A mask of snapshot formats for this repo that cgit generates links for,
  22768. restricted by the global @code{snapshots} setting.
  22769. Defaults to @samp{()}.
  22770. @end deftypevr
  22771. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
  22772. Override the default @code{source-filter}.
  22773. Defaults to @samp{""}.
  22774. @end deftypevr
  22775. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
  22776. The relative URL used to access the repository.
  22777. Defaults to @samp{""}.
  22778. @end deftypevr
  22779. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
  22780. Override the default @code{about-filter}.
  22781. Defaults to @samp{""}.
  22782. @end deftypevr
  22783. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
  22784. Flag which, when set to @samp{age}, enables date ordering in the branch
  22785. ref list, and when set to @samp{name} enables ordering by branch name.
  22786. Defaults to @samp{""}.
  22787. @end deftypevr
  22788. @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
  22789. A list of URLs which can be used to clone repo.
  22790. Defaults to @samp{()}.
  22791. @end deftypevr
  22792. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
  22793. Override the default @code{commit-filter}.
  22794. Defaults to @samp{""}.
  22795. @end deftypevr
  22796. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
  22797. Flag which, when set to @samp{date}, enables strict date ordering in the
  22798. commit log, and when set to @samp{topo} enables strict topological
  22799. ordering.
  22800. Defaults to @samp{""}.
  22801. @end deftypevr
  22802. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
  22803. The name of the default branch for this repository. If no such branch
  22804. exists in the repository, the first branch name (when sorted) is used as
  22805. default instead. By default branch pointed to by HEAD, or ``master'' if
  22806. there is no suitable HEAD.
  22807. Defaults to @samp{""}.
  22808. @end deftypevr
  22809. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
  22810. The value to show as repository description.
  22811. Defaults to @samp{""}.
  22812. @end deftypevr
  22813. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
  22814. The value to show as repository homepage.
  22815. Defaults to @samp{""}.
  22816. @end deftypevr
  22817. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
  22818. Override the default @code{email-filter}.
  22819. Defaults to @samp{""}.
  22820. @end deftypevr
  22821. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
  22822. A flag which can be used to disable the global setting
  22823. @code{enable-commit-graph?}.
  22824. Defaults to @samp{disabled}.
  22825. @end deftypevr
  22826. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
  22827. A flag which can be used to disable the global setting
  22828. @code{enable-log-filecount?}.
  22829. Defaults to @samp{disabled}.
  22830. @end deftypevr
  22831. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
  22832. A flag which can be used to disable the global setting
  22833. @code{enable-log-linecount?}.
  22834. Defaults to @samp{disabled}.
  22835. @end deftypevr
  22836. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
  22837. Flag which, when set to @code{#t}, will make cgit display remote
  22838. branches in the summary and refs views.
  22839. Defaults to @samp{disabled}.
  22840. @end deftypevr
  22841. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
  22842. A flag which can be used to override the global setting
  22843. @code{enable-subject-links?}.
  22844. Defaults to @samp{disabled}.
  22845. @end deftypevr
  22846. @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
  22847. A flag which can be used to override the global setting
  22848. @code{enable-html-serving?}.
  22849. Defaults to @samp{disabled}.
  22850. @end deftypevr
  22851. @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
  22852. Flag which, when set to @code{#t}, hides the repository from the
  22853. repository index.
  22854. Defaults to @samp{#f}.
  22855. @end deftypevr
  22856. @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
  22857. Flag which, when set to @samp{#t}, ignores the repository.
  22858. Defaults to @samp{#f}.
  22859. @end deftypevr
  22860. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
  22861. URL which specifies the source of an image which will be used as a logo
  22862. on this repo’s pages.
  22863. Defaults to @samp{""}.
  22864. @end deftypevr
  22865. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
  22866. URL loaded when clicking on the cgit logo image.
  22867. Defaults to @samp{""}.
  22868. @end deftypevr
  22869. @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
  22870. Override the default @code{owner-filter}.
  22871. Defaults to @samp{""}.
  22872. @end deftypevr
  22873. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
  22874. Text which will be used as the formatstring for a hyperlink when a
  22875. submodule is printed in a directory listing. The arguments for the
  22876. formatstring are the path and SHA1 of the submodule commit.
  22877. Defaults to @samp{""}.
  22878. @end deftypevr
  22879. @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
  22880. Text which will be used as the formatstring for a hyperlink when a
  22881. submodule with the specified subdirectory path is printed in a directory
  22882. listing.
  22883. Defaults to @samp{()}.
  22884. @end deftypevr
  22885. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
  22886. Override the default maximum statistics period.
  22887. Defaults to @samp{""}.
  22888. @end deftypevr
  22889. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
  22890. The value to show as repository name.
  22891. Defaults to @samp{""}.
  22892. @end deftypevr
  22893. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
  22894. A value used to identify the owner of the repository.
  22895. Defaults to @samp{""}.
  22896. @end deftypevr
  22897. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
  22898. An absolute path to the repository directory.
  22899. Defaults to @samp{""}.
  22900. @end deftypevr
  22901. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
  22902. A path (relative to repo) which specifies a file to include verbatim as
  22903. the ``About'' page for this repo.
  22904. Defaults to @samp{""}.
  22905. @end deftypevr
  22906. @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
  22907. The name of the current repository section - all repositories defined
  22908. after this option will inherit the current section name.
  22909. Defaults to @samp{""}.
  22910. @end deftypevr
  22911. @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
  22912. Extra options will be appended to cgitrc file.
  22913. Defaults to @samp{()}.
  22914. @end deftypevr
  22915. @end deftypevr
  22916. @deftypevr {@code{cgit-configuration} parameter} list extra-options
  22917. Extra options will be appended to cgitrc file.
  22918. Defaults to @samp{()}.
  22919. @end deftypevr
  22920. @c %end of fragment
  22921. However, it could be that you just want to get a @code{cgitrc} up and
  22922. running. In that case, you can pass an @code{opaque-cgit-configuration}
  22923. as a record to @code{cgit-service-type}. As its name indicates, an
  22924. opaque configuration does not have easy reflective capabilities.
  22925. Available @code{opaque-cgit-configuration} fields are:
  22926. @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
  22927. The cgit package.
  22928. @end deftypevr
  22929. @deftypevr {@code{opaque-cgit-configuration} parameter} string string
  22930. The contents of the @code{cgitrc}, as a string.
  22931. @end deftypevr
  22932. For example, if your @code{cgitrc} is just the empty string, you
  22933. could instantiate a cgit service like this:
  22934. @lisp
  22935. (service cgit-service-type
  22936. (opaque-cgit-configuration
  22937. (cgitrc "")))
  22938. @end lisp
  22939. @subsubheading Gitolite Service
  22940. @cindex Gitolite service
  22941. @cindex Git, hosting
  22942. @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
  22943. repositories on a central server.
  22944. Gitolite can handle multiple repositories and users, and supports flexible
  22945. configuration of the permissions for the users on the repositories.
  22946. The following example will configure Gitolite using the default @code{git}
  22947. user, and the provided SSH public key.
  22948. @lisp
  22949. (service gitolite-service-type
  22950. (gitolite-configuration
  22951. (admin-pubkey (plain-file
  22952. "yourname.pub"
  22953. "ssh-rsa AAAA... guix@@example.com"))))
  22954. @end lisp
  22955. Gitolite is configured through a special admin repository which you can clone,
  22956. for example, if you setup Gitolite on @code{example.com}, you would run the
  22957. following command to clone the admin repository.
  22958. @example
  22959. git clone git@@example.com:gitolite-admin
  22960. @end example
  22961. When the Gitolite service is activated, the provided @code{admin-pubkey} will
  22962. be inserted in to the @file{keydir} directory in the gitolite-admin
  22963. repository. If this results in a change in the repository, it will be
  22964. committed using the message ``gitolite setup by GNU Guix''.
  22965. @deftp {Data Type} gitolite-configuration
  22966. Data type representing the configuration for @code{gitolite-service-type}.
  22967. @table @asis
  22968. @item @code{package} (default: @var{gitolite})
  22969. Gitolite package to use.
  22970. @item @code{user} (default: @var{git})
  22971. User to use for Gitolite. This will be user that you use when accessing
  22972. Gitolite over SSH.
  22973. @item @code{group} (default: @var{git})
  22974. Group to use for Gitolite.
  22975. @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
  22976. Directory in which to store the Gitolite configuration and repositories.
  22977. @item @code{rc-file} (default: @var{(gitolite-rc-file)})
  22978. A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
  22979. representing the configuration for Gitolite.
  22980. @item @code{admin-pubkey} (default: @var{#f})
  22981. A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
  22982. setup Gitolite. This will be inserted in to the @file{keydir} directory
  22983. within the gitolite-admin repository.
  22984. To specify the SSH key as a string, use the @code{plain-file} function.
  22985. @lisp
  22986. (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
  22987. @end lisp
  22988. @end table
  22989. @end deftp
  22990. @deftp {Data Type} gitolite-rc-file
  22991. Data type representing the Gitolite RC file.
  22992. @table @asis
  22993. @item @code{umask} (default: @code{#o0077})
  22994. This controls the permissions Gitolite sets on the repositories and their
  22995. contents.
  22996. A value like @code{#o0027} will give read access to the group used by Gitolite
  22997. (by default: @code{git}). This is necessary when using Gitolite with software
  22998. like cgit or gitweb.
  22999. @item @code{git-config-keys} (default: @code{""})
  23000. Gitolite allows you to set git config values using the @samp{config}
  23001. keyword. This setting allows control over the config keys to accept.
  23002. @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
  23003. Set the role names allowed to be used by users running the perms command.
  23004. @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
  23005. This setting controls the commands and features to enable within Gitolite.
  23006. @end table
  23007. @end deftp
  23008. @node Game Services
  23009. @subsection Game Services
  23010. @subsubheading The Battle for Wesnoth Service
  23011. @cindex wesnothd
  23012. @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
  23013. based tactical strategy game, with several single player campaigns, and
  23014. multiplayer games (both networked and local).
  23015. @defvar {Scheme Variable} wesnothd-service-type
  23016. Service type for the wesnothd service. Its value must be a
  23017. @code{wesnothd-configuration} object. To run wesnothd in the default
  23018. configuration, instantiate it as:
  23019. @lisp
  23020. (service wesnothd-service-type)
  23021. @end lisp
  23022. @end defvar
  23023. @deftp {Data Type} wesnothd-configuration
  23024. Data type representing the configuration of @command{wesnothd}.
  23025. @table @asis
  23026. @item @code{package} (default: @code{wesnoth-server})
  23027. The wesnoth server package to use.
  23028. @item @code{port} (default: @code{15000})
  23029. The port to bind the server to.
  23030. @end table
  23031. @end deftp
  23032. @node PAM Mount Service
  23033. @subsection PAM Mount Service
  23034. @cindex pam-mount
  23035. The @code{(gnu services pam-mount)} module provides a service allowing
  23036. users to mount volumes when they log in. It should be able to mount any
  23037. volume format supported by the system.
  23038. @defvar {Scheme Variable} pam-mount-service-type
  23039. Service type for PAM Mount support.
  23040. @end defvar
  23041. @deftp {Data Type} pam-mount-configuration
  23042. Data type representing the configuration of PAM Mount.
  23043. It takes the following parameters:
  23044. @table @asis
  23045. @item @code{rules}
  23046. The configuration rules that will be used to generate
  23047. @file{/etc/security/pam_mount.conf.xml}.
  23048. The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
  23049. Guile Reference Manual}), and the default ones don't mount anything for
  23050. anyone at login:
  23051. @lisp
  23052. `((debug (@@ (enable "0")))
  23053. (mntoptions (@@ (allow ,(string-join
  23054. '("nosuid" "nodev" "loop"
  23055. "encryption" "fsck" "nonempty"
  23056. "allow_root" "allow_other")
  23057. ","))))
  23058. (mntoptions (@@ (require "nosuid,nodev")))
  23059. (logout (@@ (wait "0")
  23060. (hup "0")
  23061. (term "no")
  23062. (kill "no")))
  23063. (mkmountpoint (@@ (enable "1")
  23064. (remove "true"))))
  23065. @end lisp
  23066. Some @code{volume} elements must be added to automatically mount volumes
  23067. at login. Here's an example allowing the user @code{alice} to mount her
  23068. encrypted @env{HOME} directory and allowing the user @code{bob} to mount
  23069. the partition where he stores his data:
  23070. @lisp
  23071. (define pam-mount-rules
  23072. `((debug (@@ (enable "0")))
  23073. (volume (@@ (user "alice")
  23074. (fstype "crypt")
  23075. (path "/dev/sda2")
  23076. (mountpoint "/home/alice")))
  23077. (volume (@@ (user "bob")
  23078. (fstype "auto")
  23079. (path "/dev/sdb3")
  23080. (mountpoint "/home/bob/data")
  23081. (options "defaults,autodefrag,compress")))
  23082. (mntoptions (@@ (allow ,(string-join
  23083. '("nosuid" "nodev" "loop"
  23084. "encryption" "fsck" "nonempty"
  23085. "allow_root" "allow_other")
  23086. ","))))
  23087. (mntoptions (@@ (require "nosuid,nodev")))
  23088. (logout (@@ (wait "0")
  23089. (hup "0")
  23090. (term "no")
  23091. (kill "no")))
  23092. (mkmountpoint (@@ (enable "1")
  23093. (remove "true")))))
  23094. (service pam-mount-service-type
  23095. (pam-mount-configuration
  23096. (rules pam-mount-rules)))
  23097. @end lisp
  23098. The complete list of possible options can be found in the man page for
  23099. @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
  23100. @end table
  23101. @end deftp
  23102. @node Guix Services
  23103. @subsection Guix Services
  23104. @subsubheading Guix Build Coordinator
  23105. The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
  23106. Coordinator} aids in distributing derivation builds among machines
  23107. running an @dfn{agent}. The build daemon is still used to build the
  23108. derivations, but the Guix Build Coordinator manages allocating builds
  23109. and working with the results.
  23110. @quotation Note
  23111. This service is considered experimental. Configuration options may be
  23112. changed in a backwards-incompatible manner, and not all features have
  23113. been thorougly tested.
  23114. @end quotation
  23115. The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
  23116. more connected @dfn{agent} processes. The coordinator process handles
  23117. clients submitting builds, and allocating builds to agents. The agent
  23118. processes talk to a build daemon to actually perform the builds, then
  23119. send the results back to the coordinator.
  23120. There is a script to run the coordinator component of the Guix Build
  23121. Coordinator, but the Guix service uses a custom Guile script instead, to
  23122. provide better integration with G-expressions used in the configuration.
  23123. @defvar {Scheme Variable} guix-build-coordinator-service-type
  23124. Service type for the Guix Build Coordinator. Its value must be a
  23125. @code{guix-build-coordinator-configuration} object.
  23126. @end defvar
  23127. @deftp {Data Type} guix-build-coordinator-configuration
  23128. Data type representing the configuration of the Guix Build Coordinator.
  23129. @table @asis
  23130. @item @code{package} (default: @code{guix-build-coordinator})
  23131. The Guix Build Coordinator package to use.
  23132. @item @code{user} (default: @code{"guix-build-coordinator"})
  23133. The system user to run the service as.
  23134. @item @code{group} (default: @code{"guix-build-coordinator"})
  23135. The system group to run the service as.
  23136. @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
  23137. The URI to use for the database.
  23138. @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
  23139. The URI describing how to listen to requests from agent processes.
  23140. @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
  23141. The URI describing how to listen to requests from clients. The client
  23142. API allows submitting builds and currently isn't authenticated, so take
  23143. care when configuring this value.
  23144. @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
  23145. A G-expression for the allocation strategy to be used. This is a
  23146. procedure that takes the datastore as an argument and populates the
  23147. allocation plan in the database.
  23148. @item @code{hooks} (default: @var{'()})
  23149. An association list of hooks. These provide a way to execute arbitrary
  23150. code upon certain events, like a build result being processed.
  23151. @item @code{guile} (default: @code{guile-3.0-latest})
  23152. The Guile package with which to run the Guix Build Coordinator.
  23153. @end table
  23154. @end deftp
  23155. @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
  23156. Service type for a Guix Build Coordinator agent. Its value must be a
  23157. @code{guix-build-coordinator-agent-configuration} object.
  23158. @end defvar
  23159. @deftp {Data Type} guix-build-coordinator-agent-configuration
  23160. Data type representing the configuration a Guix Build Coordinator agent.
  23161. @table @asis
  23162. @item @code{package} (default: @code{guix-build-coordinator})
  23163. The Guix Build Coordinator package to use.
  23164. @item @code{user} (default: @code{"guix-build-coordinator-agent"})
  23165. The system user to run the service as.
  23166. @item @code{coordinator} (default: @code{"http://localhost:8745"})
  23167. The URI to use when connecting to the coordinator.
  23168. @item @code{uuid}
  23169. The UUID of the agent. This should be generated by the coordinator
  23170. process, stored in the coordinator database, and used by the intended
  23171. agent.
  23172. @item @code{password} (default: @code{#f})
  23173. The password to use when connecting to the coordinator. A file to read
  23174. the password from can also be specified, and this is more secure.
  23175. @item @code{password-file} (default: @code{#f})
  23176. A file containing the password to use when connecting to the
  23177. coordinator.
  23178. @item @code{systems} (default: @code{#f})
  23179. The systems for which this agent should fetch builds. The agent process
  23180. will use the current system it's running on as the default.
  23181. @item @code{max-parallel-builds} (default: @code{1})
  23182. The number of builds to perform in parallel.
  23183. @item @code{derivation-substitute-urls} (default: @code{#f})
  23184. URLs from which to attempt to fetch substitutes for derivations, if the
  23185. derivations aren't already available.
  23186. @item @code{non-derivation-substitute-urls} (default: @code{#f})
  23187. URLs from which to attempt to fetch substitutes for build inputs, if the
  23188. input store items aren't already available.
  23189. @end table
  23190. @end deftp
  23191. The Guix Build Coordinator package contains a script to query an
  23192. instance of the Guix Data Service for derivations to build, and then
  23193. submit builds for those derivations to the coordinator. The service
  23194. type below assists in running this script. This is an additional tool
  23195. that may be useful when building derivations contained within an
  23196. instance of the Guix Data Service.
  23197. @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
  23198. Service type for the
  23199. guix-build-coordinator-queue-builds-from-guix-data-service script. Its
  23200. value must be a @code{guix-build-coordinator-queue-builds-configuration}
  23201. object.
  23202. @end defvar
  23203. @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
  23204. Data type representing the options to the queue builds from guix data
  23205. service script.
  23206. @table @asis
  23207. @item @code{package} (default: @code{guix-build-coordinator})
  23208. The Guix Build Coordinator package to use.
  23209. @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
  23210. The system user to run the service as.
  23211. @item @code{coordinator} (default: @code{"http://localhost:8745"})
  23212. The URI to use when connecting to the coordinator.
  23213. @item @code{systems} (default: @code{#f})
  23214. The systems for which to fetch derivations to build.
  23215. @item @code{systems-and-targets} (default: @code{#f})
  23216. An association list of system and target pairs for which to fetch
  23217. derivations to build.
  23218. @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
  23219. The Guix Data Service instance from which to query to find out about
  23220. derivations to build.
  23221. @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
  23222. A file to record which commits have been processed, to avoid needlessly
  23223. processing them again if the service is restarted.
  23224. @end table
  23225. @end deftp
  23226. @subsubheading Guix Data Service
  23227. The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
  23228. and provides data about GNU Guix. This includes information about
  23229. packages, derivations and lint warnings.
  23230. The data is stored in a PostgreSQL database, and available through a web
  23231. interface.
  23232. @defvar {Scheme Variable} guix-data-service-type
  23233. Service type for the Guix Data Service. Its value must be a
  23234. @code{guix-data-service-configuration} object. The service optionally
  23235. extends the getmail service, as the guix-commits mailing list is used to
  23236. find out about changes in the Guix git repository.
  23237. @end defvar
  23238. @deftp {Data Type} guix-data-service-configuration
  23239. Data type representing the configuration of the Guix Data Service.
  23240. @table @asis
  23241. @item @code{package} (default: @code{guix-data-service})
  23242. The Guix Data Service package to use.
  23243. @item @code{user} (default: @code{"guix-data-service"})
  23244. The system user to run the service as.
  23245. @item @code{group} (default: @code{"guix-data-service"})
  23246. The system group to run the service as.
  23247. @item @code{port} (default: @code{8765})
  23248. The port to bind the web service to.
  23249. @item @code{host} (default: @code{"127.0.0.1"})
  23250. The host to bind the web service to.
  23251. @item @code{getmail-idle-mailboxes} (default: @code{#f})
  23252. If set, this is the list of mailboxes that the getmail service will be
  23253. configured to listen to.
  23254. @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
  23255. If set, this is the @code{getmail-retriever-configuration} object with
  23256. which to configure getmail to fetch mail from the guix-commits mailing
  23257. list.
  23258. @item @code{extra-options} (default: @var{'()})
  23259. Extra command line options for @code{guix-data-service}.
  23260. @item @code{extra-process-jobs-options} (default: @var{'()})
  23261. Extra command line options for @code{guix-data-service-process-jobs}.
  23262. @end table
  23263. @end deftp
  23264. @node Linux Services
  23265. @subsection Linux Services
  23266. @cindex oom
  23267. @cindex out of memory killer
  23268. @cindex earlyoom
  23269. @cindex early out of memory daemon
  23270. @subsubheading Early OOM Service
  23271. @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
  23272. Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
  23273. space and provides a more responsive and configurable alternative to the
  23274. in-kernel OOM killer. It is useful to prevent the system from becoming
  23275. unresponsive when it runs out of memory.
  23276. @deffn {Scheme Variable} earlyoom-service-type
  23277. The service type for running @command{earlyoom}, the Early OOM daemon.
  23278. Its value must be a @code{earlyoom-configuration} object, described
  23279. below. The service can be instantiated in its default configuration
  23280. with:
  23281. @lisp
  23282. (service earlyoom-service-type)
  23283. @end lisp
  23284. @end deffn
  23285. @deftp {Data Type} earlyoom-configuration
  23286. This is the configuration record for the @code{earlyoom-service-type}.
  23287. @table @asis
  23288. @item @code{earlyoom} (default: @var{earlyoom})
  23289. The Earlyoom package to use.
  23290. @item @code{minimum-available-memory} (default: @code{10})
  23291. The threshold for the minimum @emph{available} memory, in percentages.
  23292. @item @code{minimum-free-swap} (default: @code{10})
  23293. The threshold for the minimum free swap memory, in percentages.
  23294. @item @code{prefer-regexp} (default: @code{#f})
  23295. A regular expression (as a string) to match the names of the processes
  23296. that should be preferably killed.
  23297. @item @code{avoid-regexp} (default: @code{#f})
  23298. A regular expression (as a string) to match the names of the processes
  23299. that should @emph{not} be killed.
  23300. @item @code{memory-report-interval} (default: @code{0})
  23301. The interval in seconds at which a memory report is printed. It is
  23302. disabled by default.
  23303. @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
  23304. A boolean indicating whether the positive adjustments set in
  23305. @file{/proc/*/oom_score_adj} should be ignored.
  23306. @item @code{show-debug-messages?} (default: @code{#f})
  23307. A boolean indicating whether debug messages should be printed. The logs
  23308. are saved at @file{/var/log/earlyoom.log}.
  23309. @item @code{send-notification-command} (default: @code{#f})
  23310. This can be used to provide a custom command used for sending
  23311. notifications.
  23312. @end table
  23313. @end deftp
  23314. @cindex modprobe
  23315. @cindex kernel module loader
  23316. @subsubheading Kernel Module Loader Service
  23317. The kernel module loader service allows one to load loadable kernel
  23318. modules at boot. This is especially useful for modules that don't
  23319. autoload and need to be manually loaded, as it's the case with
  23320. @code{ddcci}.
  23321. @deffn {Scheme Variable} kernel-module-loader-service-type
  23322. The service type for loading loadable kernel modules at boot with
  23323. @command{modprobe}. Its value must be a list of strings representing
  23324. module names. For example loading the drivers provided by
  23325. @code{ddcci-driver-linux}, in debugging mode by passing some module
  23326. parameters, can be done as follow:
  23327. @lisp
  23328. (use-modules (gnu) (gnu services))
  23329. (use-package-modules linux)
  23330. (use-service-modules linux)
  23331. (define ddcci-config
  23332. (plain-file "ddcci.conf"
  23333. "options ddcci dyndbg delay=120"))
  23334. (operating-system
  23335. ...
  23336. (services (cons* (service kernel-module-loader-service-type
  23337. '("ddcci" "ddcci_backlight"))
  23338. (simple-service 'ddcci-config etc-service-type
  23339. (list `("modprobe.d/ddcci.conf"
  23340. ,ddcci-config)))
  23341. %base-services))
  23342. (kernel-loadable-modules (list ddcci-driver-linux)))
  23343. @end lisp
  23344. @end deffn
  23345. @cindex zram
  23346. @cindex compressed swap
  23347. @cindex Compressed RAM-based block devices
  23348. @subsubheading Zram Device Service
  23349. The Zram device service provides a compressed swap device in system
  23350. memory. The Linux Kernel documentation has more information about
  23351. @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
  23352. devices.
  23353. @deffn {Scheme Variable} zram-device-service-type
  23354. This service creates the zram block device, formats it as swap and
  23355. enables it as a swap device. The service's value is a
  23356. @code{zram-device-configuration} record.
  23357. @deftp {Data Type} zram-device-configuration
  23358. This is the data type representing the configuration for the zram-device
  23359. service.
  23360. @table @asis
  23361. @item @code{size} (default @code{"1G"})
  23362. This is the amount of space you wish to provide for the zram device. It
  23363. accepts a string and can be a number of bytes or use a suffix, eg.:
  23364. @code{"512M"} or @code{1024000}.
  23365. @item @code{compression-algorithm} (default @code{'lzo})
  23366. This is the compression algorithm you wish to use. It is difficult to
  23367. list all the possible compression options, but common ones supported by
  23368. Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
  23369. @item @code{memory-limit} (default @code{0})
  23370. This is the maximum amount of memory which the zram device can use.
  23371. Setting it to '0' disables the limit. While it is generally expected
  23372. that compression will be 2:1, it is possible that uncompressable data
  23373. can be written to swap and this is a method to limit how much memory can
  23374. be used. It accepts a string and can be a number of bytes or use a
  23375. suffix, eg.: @code{"2G"}.
  23376. @item @code{priority} (default @code{-1})
  23377. This is the priority of the swap device created from the zram device.
  23378. @code{swapon} accepts values between -1 and 32767, with higher values
  23379. indicating higher priority. Higher priority swap will generally be used
  23380. first.
  23381. @end table
  23382. @end deftp
  23383. @end deffn
  23384. @node Hurd Services
  23385. @subsection Hurd Services
  23386. @defvr {Scheme Variable} hurd-console-service-type
  23387. This service starts the fancy @code{VGA} console client on the Hurd.
  23388. The service's value is a @code{hurd-console-configuration} record.
  23389. @end defvr
  23390. @deftp {Data Type} hurd-console-configuration
  23391. This is the data type representing the configuration for the
  23392. hurd-console-service.
  23393. @table @asis
  23394. @item @code{hurd} (default: @var{hurd})
  23395. The Hurd package to use.
  23396. @end table
  23397. @end deftp
  23398. @defvr {Scheme Variable} hurd-getty-service-type
  23399. This service starts a tty using the Hurd @code{getty} program.
  23400. The service's value is a @code{hurd-getty-configuration} record.
  23401. @end defvr
  23402. @deftp {Data Type} hurd-getty-configuration
  23403. This is the data type representing the configuration for the
  23404. hurd-getty-service.
  23405. @table @asis
  23406. @item @code{hurd} (default: @var{hurd})
  23407. The Hurd package to use.
  23408. @item @code{tty}
  23409. The name of the console this Getty runs on---e.g., @code{"tty1"}.
  23410. @item @code{baud-rate} (default: @code{38400})
  23411. An integer specifying the baud rate of the tty.
  23412. @end table
  23413. @end deftp
  23414. @node Miscellaneous Services
  23415. @subsection Miscellaneous Services
  23416. @cindex fingerprint
  23417. @subsubheading Fingerprint Service
  23418. The @code{(gnu services authentication)} module provides a DBus service to
  23419. read and identify fingerprints via a fingerprint sensor.
  23420. @defvr {Scheme Variable} fprintd-service-type
  23421. The service type for @command{fprintd}, which provides the fingerprint
  23422. reading capability.
  23423. @lisp
  23424. (service fprintd-service-type)
  23425. @end lisp
  23426. @end defvr
  23427. @cindex sysctl
  23428. @subsubheading System Control Service
  23429. The @code{(gnu services sysctl)} provides a service to configure kernel
  23430. parameters at boot.
  23431. @defvr {Scheme Variable} sysctl-service-type
  23432. The service type for @command{sysctl}, which modifies kernel parameters
  23433. under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
  23434. instantiated as:
  23435. @lisp
  23436. (service sysctl-service-type
  23437. (sysctl-configuration
  23438. (settings '(("net.ipv4.ip_forward" . "1")))))
  23439. @end lisp
  23440. @end defvr
  23441. @deftp {Data Type} sysctl-configuration
  23442. The data type representing the configuration of @command{sysctl}.
  23443. @table @asis
  23444. @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
  23445. The @command{sysctl} executable to use.
  23446. @item @code{settings} (default: @code{'()})
  23447. An association list specifies kernel parameters and their values.
  23448. @end table
  23449. @end deftp
  23450. @cindex pcscd
  23451. @subsubheading PC/SC Smart Card Daemon Service
  23452. The @code{(gnu services security-token)} module provides the following service
  23453. to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
  23454. daemon program for pcsc-lite and the MuscleCard framework. It is a resource
  23455. manager that coordinates communications with smart card readers, smart cards
  23456. and cryptographic tokens that are connected to the system.
  23457. @defvr {Scheme Variable} pcscd-service-type
  23458. Service type for the @command{pcscd} service. Its value must be a
  23459. @code{pcscd-configuration} object. To run pcscd in the default
  23460. configuration, instantiate it as:
  23461. @lisp
  23462. (service pcscd-service-type)
  23463. @end lisp
  23464. @end defvr
  23465. @deftp {Data Type} pcscd-configuration
  23466. The data type representing the configuration of @command{pcscd}.
  23467. @table @asis
  23468. @item @code{pcsc-lite} (default: @code{pcsc-lite})
  23469. The pcsc-lite package that provides pcscd.
  23470. @item @code{usb-drivers} (default: @code{(list ccid)})
  23471. List of packages that provide USB drivers to pcscd. Drivers are expected to be
  23472. under @file{pcsc/drivers} in the store directory of the package.
  23473. @end table
  23474. @end deftp
  23475. @cindex lirc
  23476. @subsubheading Lirc Service
  23477. The @code{(gnu services lirc)} module provides the following service.
  23478. @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
  23479. [#:device #f] [#:driver #f] [#:config-file #f] @
  23480. [#:extra-options '()]
  23481. Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
  23482. decodes infrared signals from remote controls.
  23483. Optionally, @var{device}, @var{driver} and @var{config-file}
  23484. (configuration file name) may be specified. See @command{lircd} manual
  23485. for details.
  23486. Finally, @var{extra-options} is a list of additional command-line options
  23487. passed to @command{lircd}.
  23488. @end deffn
  23489. @cindex spice
  23490. @subsubheading Spice Service
  23491. The @code{(gnu services spice)} module provides the following service.
  23492. @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
  23493. Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
  23494. that enables sharing the clipboard with a vm and setting the guest display
  23495. resolution when the graphical console window resizes.
  23496. @end deffn
  23497. @cindex inputattach
  23498. @subsubheading inputattach Service
  23499. @cindex tablet input, for Xorg
  23500. @cindex touchscreen input, for Xorg
  23501. The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
  23502. use input devices such as Wacom tablets, touchscreens, or joysticks with the
  23503. Xorg display server.
  23504. @deffn {Scheme Variable} inputattach-service-type
  23505. Type of a service that runs @command{inputattach} on a device and
  23506. dispatches events from it.
  23507. @end deffn
  23508. @deftp {Data Type} inputattach-configuration
  23509. @table @asis
  23510. @item @code{device-type} (default: @code{"wacom"})
  23511. The type of device to connect to. Run @command{inputattach --help}, from the
  23512. @code{inputattach} package, to see the list of supported device types.
  23513. @item @code{device} (default: @code{"/dev/ttyS0"})
  23514. The device file to connect to the device.
  23515. @item @code{baud-rate} (default: @code{#f})
  23516. Baud rate to use for the serial connection.
  23517. Should be a number or @code{#f}.
  23518. @item @code{log-file} (default: @code{#f})
  23519. If true, this must be the name of a file to log messages to.
  23520. @end table
  23521. @end deftp
  23522. @subsubheading Dictionary Service
  23523. @cindex dictionary
  23524. The @code{(gnu services dict)} module provides the following service:
  23525. @defvr {Scheme Variable} dicod-service-type
  23526. This is the type of the service that runs the @command{dicod} daemon, an
  23527. implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
  23528. @end defvr
  23529. @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
  23530. Return a service that runs the @command{dicod} daemon, an implementation
  23531. of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
  23532. The optional @var{config} argument specifies the configuration for
  23533. @command{dicod}, which should be a @code{<dicod-configuration>} object, by
  23534. default it serves the GNU Collaborative International Dictionary of English.
  23535. You can add @command{open localhost} to your @file{~/.dico} file to make
  23536. @code{localhost} the default server for @command{dico} client
  23537. (@pxref{Initialization File,,, dico, GNU Dico Manual}).
  23538. @end deffn
  23539. @deftp {Data Type} dicod-configuration
  23540. Data type representing the configuration of dicod.
  23541. @table @asis
  23542. @item @code{dico} (default: @var{dico})
  23543. Package object of the GNU Dico dictionary server.
  23544. @item @code{interfaces} (default: @var{'("localhost")})
  23545. This is the list of IP addresses and ports and possibly socket file
  23546. names to listen to (@pxref{Server Settings, @code{listen} directive,,
  23547. dico, GNU Dico Manual}).
  23548. @item @code{handlers} (default: @var{'()})
  23549. List of @code{<dicod-handler>} objects denoting handlers (module instances).
  23550. @item @code{databases} (default: @var{(list %dicod-database:gcide)})
  23551. List of @code{<dicod-database>} objects denoting dictionaries to be served.
  23552. @end table
  23553. @end deftp
  23554. @deftp {Data Type} dicod-handler
  23555. Data type representing a dictionary handler (module instance).
  23556. @table @asis
  23557. @item @code{name}
  23558. Name of the handler (module instance).
  23559. @item @code{module} (default: @var{#f})
  23560. Name of the dicod module of the handler (instance). If it is @code{#f},
  23561. the module has the same name as the handler.
  23562. (@pxref{Modules,,, dico, GNU Dico Manual}).
  23563. @item @code{options}
  23564. List of strings or gexps representing the arguments for the module handler
  23565. @end table
  23566. @end deftp
  23567. @deftp {Data Type} dicod-database
  23568. Data type representing a dictionary database.
  23569. @table @asis
  23570. @item @code{name}
  23571. Name of the database, will be used in DICT commands.
  23572. @item @code{handler}
  23573. Name of the dicod handler (module instance) used by this database
  23574. (@pxref{Handlers,,, dico, GNU Dico Manual}).
  23575. @item @code{complex?} (default: @var{#f})
  23576. Whether the database configuration complex. The complex configuration
  23577. will need a corresponding @code{<dicod-handler>} object, otherwise not.
  23578. @item @code{options}
  23579. List of strings or gexps representing the arguments for the database
  23580. (@pxref{Databases,,, dico, GNU Dico Manual}).
  23581. @end table
  23582. @end deftp
  23583. @defvr {Scheme Variable} %dicod-database:gcide
  23584. A @code{<dicod-database>} object serving the GNU Collaborative International
  23585. Dictionary of English using the @code{gcide} package.
  23586. @end defvr
  23587. The following is an example @code{dicod-service} configuration.
  23588. @lisp
  23589. (dicod-service #:config
  23590. (dicod-configuration
  23591. (handlers (list (dicod-handler
  23592. (name "wordnet")
  23593. (module "dictorg")
  23594. (options
  23595. (list #~(string-append "dbdir=" #$wordnet))))))
  23596. (databases (list (dicod-database
  23597. (name "wordnet")
  23598. (complex? #t)
  23599. (handler "wordnet")
  23600. (options '("database=wn")))
  23601. %dicod-database:gcide))))
  23602. @end lisp
  23603. @cindex Docker
  23604. @subsubheading Docker Service
  23605. The @code{(gnu services docker)} module provides the following services.
  23606. @defvr {Scheme Variable} docker-service-type
  23607. This is the type of the service that runs @url{https://www.docker.com,Docker},
  23608. a daemon that can execute application bundles (sometimes referred to as
  23609. ``containers'') in isolated environments.
  23610. @end defvr
  23611. @deftp {Data Type} docker-configuration
  23612. This is the data type representing the configuration of Docker and Containerd.
  23613. @table @asis
  23614. @item @code{package} (default: @code{docker})
  23615. The Docker daemon package to use.
  23616. @item @code{package} (default: @code{docker-cli})
  23617. The Docker client package to use.
  23618. @item @code{containerd} (default: @var{containerd})
  23619. The Containerd package to use.
  23620. @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
  23621. The Docker user-land networking proxy package to use.
  23622. @item @code{enable-proxy?} (default @code{#t})
  23623. Enable or disable the use of the Docker user-land networking proxy.
  23624. @item @code{debug?} (default @code{#f})
  23625. Enable or disable debug output.
  23626. @item @code{enable-iptables?} (default @code{#t})
  23627. Enable or disable the addition of iptables rules.
  23628. @end table
  23629. @end deftp
  23630. @cindex Singularity, container service
  23631. @defvr {Scheme Variable} singularity-service-type
  23632. This is the type of the service that allows you to run
  23633. @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
  23634. create and run application bundles (aka. ``containers''). The value for this
  23635. service is the Singularity package to use.
  23636. The service does not install a daemon; instead, it installs helper programs as
  23637. setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
  23638. @command{singularity run} and similar commands.
  23639. @end defvr
  23640. @cindex Audit
  23641. @subsubheading Auditd Service
  23642. The @code{(gnu services auditd)} module provides the following service.
  23643. @defvr {Scheme Variable} auditd-service-type
  23644. This is the type of the service that runs
  23645. @url{https://people.redhat.com/sgrubb/audit/,auditd},
  23646. a daemon that tracks security-relevant information on your system.
  23647. Examples of things that can be tracked:
  23648. @enumerate
  23649. @item
  23650. File accesses
  23651. @item
  23652. System calls
  23653. @item
  23654. Invoked commands
  23655. @item
  23656. Failed login attempts
  23657. @item
  23658. Firewall filtering
  23659. @item
  23660. Network access
  23661. @end enumerate
  23662. @command{auditctl} from the @code{audit} package can be used in order
  23663. to add or remove events to be tracked (until the next reboot).
  23664. In order to permanently track events, put the command line arguments
  23665. of auditctl into a file called @code{audit.rules} in the configuration
  23666. directory (see below).
  23667. @command{aureport} from the @code{audit} package can be used in order
  23668. to view a report of all recorded events.
  23669. The audit daemon by default logs into the file
  23670. @file{/var/log/audit.log}.
  23671. @end defvr
  23672. @deftp {Data Type} auditd-configuration
  23673. This is the data type representing the configuration of auditd.
  23674. @table @asis
  23675. @item @code{audit} (default: @code{audit})
  23676. The audit package to use.
  23677. @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
  23678. The directory containing the configuration file for the audit package, which
  23679. must be named @code{auditd.conf}, and optionally some audit rules to
  23680. instantiate on startup.
  23681. @end table
  23682. @end deftp
  23683. @cindex rshiny
  23684. @subsubheading R-Shiny service
  23685. The @code{(gnu services science)} module provides the following service.
  23686. @defvr {Scheme Variable} rshiny-service-type
  23687. This is a type of service which is used to run a webapp created with
  23688. @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
  23689. variable and runs the provided script to call @code{runApp}.
  23690. @deftp {Data Type} rshiny-configuration
  23691. This is the data type representing the configuration of rshiny.
  23692. @table @asis
  23693. @item @code{package} (default: @code{r-shiny})
  23694. The package to use.
  23695. @item @code{binary} (defaunlt @code{"rshiny"})
  23696. The name of the binary or shell script located at @code{package/bin/} to
  23697. run when the service is run.
  23698. The common way to create this file is as follows:
  23699. @lisp
  23700. @dots{}
  23701. (let* ((out (assoc-ref %outputs "out"))
  23702. (targetdir (string-append out "/share/" ,name))
  23703. (app (string-append out "/bin/" ,name))
  23704. (Rbin (string-append (assoc-ref %build-inputs "r-min")
  23705. "/bin/Rscript")))
  23706. ;; @dots{}
  23707. (mkdir-p (string-append out "/bin"))
  23708. (call-with-output-file app
  23709. (lambda (port)
  23710. (format port
  23711. "#!~a
  23712. library(shiny)
  23713. setwd(\"~a\")
  23714. runApp(launch.browser=0, port=4202)~%\n"
  23715. Rbin targetdir))))
  23716. @end lisp
  23717. @end table
  23718. @end deftp
  23719. @end defvr
  23720. @cindex Nix
  23721. @subsubheading Nix service
  23722. The @code{(gnu services nix)} module provides the following service.
  23723. @defvr {Scheme Variable} nix-service-type
  23724. This is the type of the service that runs build daemon of the
  23725. @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
  23726. how to use it:
  23727. @lisp
  23728. (use-modules (gnu))
  23729. (use-service-modules nix)
  23730. (use-package-modules package-management)
  23731. (operating-system
  23732. ;; @dots{}
  23733. (packages (append (list nix)
  23734. %base-packages))
  23735. (services (append (list (service nix-service-type))
  23736. %base-services)))
  23737. @end lisp
  23738. After @command{guix system reconfigure} configure Nix for your user:
  23739. @itemize
  23740. @item Add a Nix channel and update it. See
  23741. @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
  23742. @item Create a symlink to your profile and activate Nix profile:
  23743. @end itemize
  23744. @example
  23745. $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
  23746. $ source /run/current-system/profile/etc/profile.d/nix.sh
  23747. @end example
  23748. @end defvr
  23749. @deftp {Data Type} nix-configuration
  23750. This data type represents the configuration of the Nix daemon.
  23751. @table @asis
  23752. @item @code{nix} (default: @code{nix})
  23753. The Nix package to use.
  23754. @item @code{sandbox} (default: @code{#t})
  23755. Specifies whether builds are sandboxed by default.
  23756. @item @code{build-sandbox-items} (default: @code{'()})
  23757. This is a list of strings or objects appended to the
  23758. @code{build-sandbox-items} field of the configuration file.
  23759. @item @code{extra-config} (default: @code{'()})
  23760. This is a list of strings or objects appended to the configuration file.
  23761. It is used to pass extra text to be added verbatim to the configuration
  23762. file.
  23763. @item @code{extra-options} (default: @code{'()})
  23764. Extra command line options for @code{nix-service-type}.
  23765. @end table
  23766. @end deftp
  23767. @node Setuid Programs
  23768. @section Setuid Programs
  23769. @cindex setuid programs
  23770. Some programs need to run with ``root'' privileges, even when they are
  23771. launched by unprivileged users. A notorious example is the
  23772. @command{passwd} program, which users can run to change their
  23773. password, and which needs to access the @file{/etc/passwd} and
  23774. @file{/etc/shadow} files---something normally restricted to root, for
  23775. obvious security reasons. To address that, these executables are
  23776. @dfn{setuid-root}, meaning that they always run with root privileges
  23777. (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
  23778. for more info about the setuid mechanism).
  23779. The store itself @emph{cannot} contain setuid programs: that would be a
  23780. security issue since any user on the system can write derivations that
  23781. populate the store (@pxref{The Store}). Thus, a different mechanism is
  23782. used: instead of changing the setuid bit directly on files that are in
  23783. the store, we let the system administrator @emph{declare} which programs
  23784. should be setuid root.
  23785. The @code{setuid-programs} field of an @code{operating-system}
  23786. declaration contains a list of G-expressions denoting the names of
  23787. programs to be setuid-root (@pxref{Using the Configuration System}).
  23788. For instance, the @command{passwd} program, which is part of the Shadow
  23789. package, can be designated by this G-expression (@pxref{G-Expressions}):
  23790. @example
  23791. #~(string-append #$shadow "/bin/passwd")
  23792. @end example
  23793. A default set of setuid programs is defined by the
  23794. @code{%setuid-programs} variable of the @code{(gnu system)} module.
  23795. @defvr {Scheme Variable} %setuid-programs
  23796. A list of G-expressions denoting common programs that are setuid-root.
  23797. The list includes commands such as @command{passwd}, @command{ping},
  23798. @command{su}, and @command{sudo}.
  23799. @end defvr
  23800. Under the hood, the actual setuid programs are created in the
  23801. @file{/run/setuid-programs} directory at system activation time. The
  23802. files in this directory refer to the ``real'' binaries, which are in the
  23803. store.
  23804. @node X.509 Certificates
  23805. @section X.509 Certificates
  23806. @cindex HTTPS, certificates
  23807. @cindex X.509 certificates
  23808. @cindex TLS
  23809. Web servers available over HTTPS (that is, HTTP over the transport-layer
  23810. security mechanism, TLS) send client programs an @dfn{X.509 certificate}
  23811. that the client can then use to @emph{authenticate} the server. To do
  23812. that, clients verify that the server's certificate is signed by a
  23813. so-called @dfn{certificate authority} (CA). But to verify the CA's
  23814. signature, clients must have first acquired the CA's certificate.
  23815. Web browsers such as GNU@tie{}IceCat include their own set of CA
  23816. certificates, such that they are able to verify CA signatures
  23817. out-of-the-box.
  23818. However, most other programs that can talk HTTPS---@command{wget},
  23819. @command{git}, @command{w3m}, etc.---need to be told where CA
  23820. certificates can be found.
  23821. @cindex @code{nss-certs}
  23822. In Guix, this is done by adding a package that provides certificates
  23823. to the @code{packages} field of the @code{operating-system} declaration
  23824. (@pxref{operating-system Reference}). Guix includes one such package,
  23825. @code{nss-certs}, which is a set of CA certificates provided as part of
  23826. Mozilla's Network Security Services.
  23827. Note that it is @emph{not} part of @code{%base-packages}, so you need to
  23828. explicitly add it. The @file{/etc/ssl/certs} directory, which is where
  23829. most applications and libraries look for certificates by default, points
  23830. to the certificates installed globally.
  23831. Unprivileged users, including users of Guix on a foreign distro,
  23832. can also install their own certificate package in
  23833. their profile. A number of environment variables need to be defined so
  23834. that applications and libraries know where to find them. Namely, the
  23835. OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
  23836. variables. Some applications add their own environment variables; for
  23837. instance, the Git version control system honors the certificate bundle
  23838. pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
  23839. would typically run something like:
  23840. @example
  23841. guix install nss-certs
  23842. export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
  23843. export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
  23844. export GIT_SSL_CAINFO="$SSL_CERT_FILE"
  23845. @end example
  23846. As another example, R requires the @env{CURL_CA_BUNDLE} environment
  23847. variable to point to a certificate bundle, so you would have to run
  23848. something like this:
  23849. @example
  23850. guix install nss-certs
  23851. export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
  23852. @end example
  23853. For other applications you may want to look up the required environment
  23854. variable in the relevant documentation.
  23855. @node Name Service Switch
  23856. @section Name Service Switch
  23857. @cindex name service switch
  23858. @cindex NSS
  23859. The @code{(gnu system nss)} module provides bindings to the
  23860. configuration file of the libc @dfn{name service switch} or @dfn{NSS}
  23861. (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
  23862. Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
  23863. extended with new ``name'' lookup methods for system databases, which
  23864. includes host names, service names, user accounts, and more (@pxref{Name
  23865. Service Switch, System Databases and Name Service Switch,, libc, The GNU
  23866. C Library Reference Manual}).
  23867. The NSS configuration specifies, for each system database, which lookup
  23868. method is to be used, and how the various methods are chained
  23869. together---for instance, under which circumstances NSS should try the
  23870. next method in the list. The NSS configuration is given in the
  23871. @code{name-service-switch} field of @code{operating-system} declarations
  23872. (@pxref{operating-system Reference, @code{name-service-switch}}).
  23873. @cindex nss-mdns
  23874. @cindex .local, host name lookup
  23875. As an example, the declaration below configures the NSS to use the
  23876. @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
  23877. back-end}, which supports host name lookups over multicast DNS (mDNS)
  23878. for host names ending in @code{.local}:
  23879. @lisp
  23880. (name-service-switch
  23881. (hosts (list %files ;first, check /etc/hosts
  23882. ;; If the above did not succeed, try
  23883. ;; with 'mdns_minimal'.
  23884. (name-service
  23885. (name "mdns_minimal")
  23886. ;; 'mdns_minimal' is authoritative for
  23887. ;; '.local'. When it returns "not found",
  23888. ;; no need to try the next methods.
  23889. (reaction (lookup-specification
  23890. (not-found => return))))
  23891. ;; Then fall back to DNS.
  23892. (name-service
  23893. (name "dns"))
  23894. ;; Finally, try with the "full" 'mdns'.
  23895. (name-service
  23896. (name "mdns")))))
  23897. @end lisp
  23898. Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
  23899. contains this configuration, so you will not have to type it if all you
  23900. want is to have @code{.local} host lookup working.
  23901. Note that, in this case, in addition to setting the
  23902. @code{name-service-switch} of the @code{operating-system} declaration,
  23903. you also need to use @code{avahi-service-type} (@pxref{Networking Services,
  23904. @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
  23905. (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
  23906. to the name service cache daemon (@pxref{Base Services,
  23907. @code{nscd-service}}).
  23908. For convenience, the following variables provide typical NSS
  23909. configurations.
  23910. @defvr {Scheme Variable} %default-nss
  23911. This is the default name service switch configuration, a
  23912. @code{name-service-switch} object.
  23913. @end defvr
  23914. @defvr {Scheme Variable} %mdns-host-lookup-nss
  23915. This is the name service switch configuration with support for host name
  23916. lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
  23917. @end defvr
  23918. The reference for name service switch configuration is given below. It
  23919. is a direct mapping of the configuration file format of the C library , so
  23920. please refer to the C library manual for more information (@pxref{NSS
  23921. Configuration File,,, libc, The GNU C Library Reference Manual}).
  23922. Compared to the configuration file format of libc NSS, it has the advantage
  23923. not only of adding this warm parenthetic feel that we like, but also
  23924. static checks: you will know about syntax errors and typos as soon as you
  23925. run @command{guix system}.
  23926. @deftp {Data Type} name-service-switch
  23927. This is the data type representation the configuration of libc's name
  23928. service switch (NSS). Each field below represents one of the supported
  23929. system databases.
  23930. @table @code
  23931. @item aliases
  23932. @itemx ethers
  23933. @itemx group
  23934. @itemx gshadow
  23935. @itemx hosts
  23936. @itemx initgroups
  23937. @itemx netgroup
  23938. @itemx networks
  23939. @itemx password
  23940. @itemx public-key
  23941. @itemx rpc
  23942. @itemx services
  23943. @itemx shadow
  23944. The system databases handled by the NSS@. Each of these fields must be a
  23945. list of @code{<name-service>} objects (see below).
  23946. @end table
  23947. @end deftp
  23948. @deftp {Data Type} name-service
  23949. This is the data type representing an actual name service and the
  23950. associated lookup action.
  23951. @table @code
  23952. @item name
  23953. A string denoting the name service (@pxref{Services in the NSS
  23954. configuration,,, libc, The GNU C Library Reference Manual}).
  23955. Note that name services listed here must be visible to nscd. This is
  23956. achieved by passing the @code{#:name-services} argument to
  23957. @code{nscd-service} the list of packages providing the needed name
  23958. services (@pxref{Base Services, @code{nscd-service}}).
  23959. @item reaction
  23960. An action specified using the @code{lookup-specification} macro
  23961. (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
  23962. Reference Manual}). For example:
  23963. @lisp
  23964. (lookup-specification (unavailable => continue)
  23965. (success => return))
  23966. @end lisp
  23967. @end table
  23968. @end deftp
  23969. @node Initial RAM Disk
  23970. @section Initial RAM Disk
  23971. @cindex initrd
  23972. @cindex initial RAM disk
  23973. For bootstrapping purposes, the Linux-Libre kernel is passed an
  23974. @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
  23975. root file system as well as an initialization script. The latter is
  23976. responsible for mounting the real root file system, and for loading any
  23977. kernel modules that may be needed to achieve that.
  23978. The @code{initrd-modules} field of an @code{operating-system}
  23979. declaration allows you to specify Linux-libre kernel modules that must
  23980. be available in the initrd. In particular, this is where you would list
  23981. modules needed to actually drive the hard disk where your root partition
  23982. is---although the default value of @code{initrd-modules} should cover
  23983. most use cases. For example, assuming you need the @code{megaraid_sas}
  23984. module in addition to the default modules to be able to access your root
  23985. file system, you would write:
  23986. @lisp
  23987. (operating-system
  23988. ;; @dots{}
  23989. (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
  23990. @end lisp
  23991. @defvr {Scheme Variable} %base-initrd-modules
  23992. This is the list of kernel modules included in the initrd by default.
  23993. @end defvr
  23994. Furthermore, if you need lower-level customization, the @code{initrd}
  23995. field of an @code{operating-system} declaration allows
  23996. you to specify which initrd you would like to use. The @code{(gnu
  23997. system linux-initrd)} module provides three ways to build an initrd: the
  23998. high-level @code{base-initrd} procedure and the low-level
  23999. @code{raw-initrd} and @code{expression->initrd} procedures.
  24000. The @code{base-initrd} procedure is intended to cover most common uses.
  24001. For example, if you want to add a bunch of kernel modules to be loaded
  24002. at boot time, you can define the @code{initrd} field of the operating
  24003. system declaration like this:
  24004. @lisp
  24005. (initrd (lambda (file-systems . rest)
  24006. ;; Create a standard initrd but set up networking
  24007. ;; with the parameters QEMU expects by default.
  24008. (apply base-initrd file-systems
  24009. #:qemu-networking? #t
  24010. rest)))
  24011. @end lisp
  24012. The @code{base-initrd} procedure also handles common use cases that
  24013. involves using the system as a QEMU guest, or as a ``live'' system with
  24014. volatile root file system.
  24015. The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
  24016. Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
  24017. such as trying to guess which kernel modules and packages should be included
  24018. to the initrd. An example use of @code{raw-initrd} is when a user has
  24019. a custom Linux kernel configuration and default kernel modules included by
  24020. @code{base-initrd} are not available.
  24021. The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
  24022. honors several options passed on the Linux kernel command line
  24023. (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
  24024. @code{-append} option of QEMU), notably:
  24025. @table @code
  24026. @item --load=@var{boot}
  24027. Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
  24028. program, once it has mounted the root file system.
  24029. Guix uses this option to yield control to a boot program that runs the
  24030. service activation programs and then spawns the GNU@tie{}Shepherd, the
  24031. initialization system.
  24032. @item --root=@var{root}
  24033. Mount @var{root} as the root file system. @var{root} can be a device
  24034. name like @code{/dev/sda1}, a file system label, or a file system UUID.
  24035. When unspecified, the device name from the root file system of the
  24036. operating system declaration is used.
  24037. @item --system=@var{system}
  24038. Have @file{/run/booted-system} and @file{/run/current-system} point to
  24039. @var{system}.
  24040. @item modprobe.blacklist=@var{modules}@dots{}
  24041. @cindex module, black-listing
  24042. @cindex black list, of kernel modules
  24043. Instruct the initial RAM disk as well as the @command{modprobe} command
  24044. (from the kmod package) to refuse to load @var{modules}. @var{modules}
  24045. must be a comma-separated list of module names---e.g.,
  24046. @code{usbkbd,9pnet}.
  24047. @item --repl
  24048. Start a read-eval-print loop (REPL) from the initial RAM disk before it
  24049. tries to load kernel modules and to mount the root file system. Our
  24050. marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
  24051. love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
  24052. Manual}, for more information on Guile's REPL.
  24053. @end table
  24054. Now that you know all the features that initial RAM disks produced by
  24055. @code{base-initrd} and @code{raw-initrd} provide,
  24056. here is how to use it and customize it further.
  24057. @cindex initrd
  24058. @cindex initial RAM disk
  24059. @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
  24060. [#:linux-modules '()] [#:mapped-devices '()] @
  24061. [#:keyboard-layout #f] @
  24062. [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
  24063. Return a derivation that builds a raw initrd. @var{file-systems} is
  24064. a list of file systems to be mounted by the initrd, possibly in addition to
  24065. the root file system specified on the kernel command line via @option{--root}.
  24066. @var{linux-modules} is a list of kernel modules to be loaded at boot time.
  24067. @var{mapped-devices} is a list of device mappings to realize before
  24068. @var{file-systems} are mounted (@pxref{Mapped Devices}).
  24069. @var{helper-packages} is a list of packages to be copied in the initrd.
  24070. It may
  24071. include @code{e2fsck/static} or other packages needed by the initrd to check
  24072. the root file system.
  24073. When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
  24074. the desired console keyboard layout. This is done before @var{mapped-devices}
  24075. are set up and before @var{file-systems} are mounted such that, should the
  24076. user need to enter a passphrase or use the REPL, this happens using the
  24077. intended keyboard layout.
  24078. When @var{qemu-networking?} is true, set up networking with the standard QEMU
  24079. parameters. When @var{virtio?} is true, load additional modules so that the
  24080. initrd can be used as a QEMU guest with para-virtualized I/O drivers.
  24081. When @var{volatile-root?} is true, the root file system is writable but any changes
  24082. to it are lost.
  24083. @end deffn
  24084. @deffn {Scheme Procedure} base-initrd @var{file-systems} @
  24085. [#:mapped-devices '()] [#:keyboard-layout #f] @
  24086. [#:qemu-networking? #f] [#:volatile-root? #f] @
  24087. [#:linux-modules '()]
  24088. Return as a file-like object a generic initrd, with kernel
  24089. modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
  24090. mounted by the initrd, possibly in addition to the root file system specified
  24091. on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
  24092. mappings to realize before @var{file-systems} are mounted.
  24093. When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
  24094. the desired console keyboard layout. This is done before @var{mapped-devices}
  24095. are set up and before @var{file-systems} are mounted such that, should the
  24096. user need to enter a passphrase or use the REPL, this happens using the
  24097. intended keyboard layout.
  24098. @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
  24099. The initrd is automatically populated with all the kernel modules necessary
  24100. for @var{file-systems} and for the given options. Additional kernel
  24101. modules can be listed in @var{linux-modules}. They will be added to the initrd, and
  24102. loaded at boot time in the order in which they appear.
  24103. @end deffn
  24104. Needless to say, the initrds we produce and use embed a
  24105. statically-linked Guile, and the initialization program is a Guile
  24106. program. That gives a lot of flexibility. The
  24107. @code{expression->initrd} procedure builds such an initrd, given the
  24108. program to run in that initrd.
  24109. @deffn {Scheme Procedure} expression->initrd @var{exp} @
  24110. [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
  24111. Return as a file-like object a Linux initrd (a gzipped cpio archive)
  24112. containing @var{guile} and that evaluates @var{exp}, a G-expression,
  24113. upon booting. All the derivations referenced by @var{exp} are
  24114. automatically copied to the initrd.
  24115. @end deffn
  24116. @node Bootloader Configuration
  24117. @section Bootloader Configuration
  24118. @cindex bootloader
  24119. @cindex boot loader
  24120. The operating system supports multiple bootloaders. The bootloader is
  24121. configured using @code{bootloader-configuration} declaration. All the
  24122. fields of this structure are bootloader agnostic except for one field,
  24123. @code{bootloader} that indicates the bootloader to be configured and
  24124. installed.
  24125. Some of the bootloaders do not honor every field of
  24126. @code{bootloader-configuration}. For instance, the extlinux
  24127. bootloader does not support themes and thus ignores the @code{theme}
  24128. field.
  24129. @deftp {Data Type} bootloader-configuration
  24130. The type of a bootloader configuration declaration.
  24131. @table @asis
  24132. @item @code{bootloader}
  24133. @cindex EFI, bootloader
  24134. @cindex UEFI, bootloader
  24135. @cindex BIOS, bootloader
  24136. The bootloader to use, as a @code{bootloader} object. For now
  24137. @code{grub-bootloader}, @code{grub-efi-bootloader},
  24138. @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
  24139. @code{u-boot-bootloader} are supported.
  24140. @cindex ARM, bootloaders
  24141. @cindex AArch64, bootloaders
  24142. Available bootloaders are described in @code{(gnu bootloader @dots{})}
  24143. modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
  24144. of bootloaders for a wide range of ARM and AArch64 systems, using the
  24145. @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
  24146. @vindex grub-efi-bootloader
  24147. @code{grub-efi-bootloader} allows to boot on modern systems using the
  24148. @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
  24149. use if the installation image contains a @file{/sys/firmware/efi} directory
  24150. when you boot it on your system.
  24151. @vindex grub-bootloader
  24152. @code{grub-bootloader} allows you to boot in particular Intel-based machines
  24153. in ``legacy'' BIOS mode.
  24154. @vindex grub-efi-netboot-bootloader
  24155. @code{grub-efi-netboot-bootloader} allows you to boot your system over network
  24156. through TFTP@. In combination with an NFS root file system this allows you to
  24157. build a diskless Guix system.
  24158. The installation of the @code{grub-efi-netboot-bootloader} generates the content
  24159. of the TFTP root directory at @code{target}
  24160. (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
  24161. You may want to mount your TFTP server directory onto @code{target} to move the
  24162. required files to the TFTP server automatically.
  24163. If you plan to use an NFS root file system as well (actually if you mount the
  24164. store from an NFS share), then the TFTP server needs to serve the file
  24165. @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
  24166. image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
  24167. initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
  24168. files from the store will be accessed by GRUB through TFTP with their normal
  24169. store path, for example as
  24170. @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
  24171. Two symlinks are created to make this possible. The first symlink is
  24172. @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
  24173. @file{../../../boot/grub/grub.cfg},
  24174. where @code{target} may be @file{/boot}. In this case the link is not leaving
  24175. the served TFTP root directory, but otherwise it does. The second link is
  24176. @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
  24177. is leaving the served TFTP root directory.
  24178. The assumption behind all this is that you have an NFS server exporting the root
  24179. file system for your Guix system, and additionally a TFTP server exporting your
  24180. @code{target} directory—usually @file{/boot}—from that same root file system for
  24181. your Guix system. In this constellation the symlinks will work.
  24182. For other constellations you will have to program your own bootloader installer,
  24183. which then takes care to make necessary files from the store accessible through
  24184. TFTP, for example by copying them into the TFTP root directory at @code{target}.
  24185. It is important to note that symlinks pointing outside the TFTP root directory
  24186. may need to be allowed in the configuration of your TFTP server. Further the
  24187. store link exposes the whole store through TFTP@. Both points need to be
  24188. considered carefully for security aspects.
  24189. Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
  24190. NFS servers, you also need a properly configured DHCP server to make the booting
  24191. over netboot possible. For all this we can currently only recommend you to look
  24192. for instructions about @acronym{PXE, Preboot eXecution Environment}.
  24193. @item @code{target}
  24194. This is a string denoting the target onto which to install the
  24195. bootloader.
  24196. The interpretation depends on the bootloader in question. For
  24197. @code{grub-bootloader}, for example, it should be a device name understood by
  24198. the bootloader @command{installer} command, such as @code{/dev/sda} or
  24199. @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
  24200. @code{grub-efi-bootloader}, it should be the mount point of the EFI file
  24201. system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
  24202. @code{target} should be the mount point corresponding to the TFTP root
  24203. directory of your TFTP server.
  24204. @item @code{menu-entries} (default: @code{()})
  24205. A possibly empty list of @code{menu-entry} objects (see below), denoting
  24206. entries to appear in the bootloader menu, in addition to the current
  24207. system entry and the entry pointing to previous system generations.
  24208. @item @code{default-entry} (default: @code{0})
  24209. The index of the default boot menu entry. Index 0 is for the entry of the
  24210. current system.
  24211. @item @code{timeout} (default: @code{5})
  24212. The number of seconds to wait for keyboard input before booting. Set to
  24213. 0 to boot immediately, and to -1 to wait indefinitely.
  24214. @cindex keyboard layout, for the bootloader
  24215. @item @code{keyboard-layout} (default: @code{#f})
  24216. If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
  24217. layout, usually US@tie{}English (``qwerty'').
  24218. Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
  24219. Layout}).
  24220. @quotation Note
  24221. This option is currently ignored by bootloaders other than @code{grub} and
  24222. @code{grub-efi}.
  24223. @end quotation
  24224. @item @code{theme} (default: @var{#f})
  24225. The bootloader theme object describing the theme to use. If no theme
  24226. is provided, some bootloaders might use a default theme, that's true
  24227. for GRUB.
  24228. @item @code{terminal-outputs} (default: @code{'(gfxterm)})
  24229. The output terminals used for the bootloader boot menu, as a list of
  24230. symbols. GRUB accepts the values: @code{console}, @code{serial},
  24231. @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
  24232. @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
  24233. corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
  24234. configuration,,, grub,GNU GRUB manual}).
  24235. @item @code{terminal-inputs} (default: @code{'()})
  24236. The input terminals used for the bootloader boot menu, as a list of
  24237. symbols. For GRUB, the default is the native platform terminal as
  24238. determined at run-time. GRUB accepts the values: @code{console},
  24239. @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
  24240. @code{usb_keyboard}. This field corresponds to the GRUB variable
  24241. @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
  24242. manual}).
  24243. @item @code{serial-unit} (default: @code{#f})
  24244. The serial unit used by the bootloader, as an integer from 0 to 3.
  24245. For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
  24246. corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
  24247. @item @code{serial-speed} (default: @code{#f})
  24248. The speed of the serial interface, as an integer. For GRUB, the
  24249. default value is chosen at run-time; currently GRUB chooses
  24250. 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
  24251. @end table
  24252. @end deftp
  24253. @cindex dual boot
  24254. @cindex boot menu
  24255. Should you want to list additional boot menu entries @i{via} the
  24256. @code{menu-entries} field above, you will need to create them with the
  24257. @code{menu-entry} form. For example, imagine you want to be able to
  24258. boot another distro (hard to imagine!), you can define a menu entry
  24259. along these lines:
  24260. @lisp
  24261. (menu-entry
  24262. (label "The Other Distro")
  24263. (linux "/boot/old/vmlinux-2.6.32")
  24264. (linux-arguments '("root=/dev/sda2"))
  24265. (initrd "/boot/old/initrd"))
  24266. @end lisp
  24267. Details below.
  24268. @deftp {Data Type} menu-entry
  24269. The type of an entry in the bootloader menu.
  24270. @table @asis
  24271. @item @code{label}
  24272. The label to show in the menu---e.g., @code{"GNU"}.
  24273. @item @code{linux} (default: @code{#f})
  24274. The Linux kernel image to boot, for example:
  24275. @lisp
  24276. (file-append linux-libre "/bzImage")
  24277. @end lisp
  24278. For GRUB, it is also possible to specify a device explicitly in the
  24279. file path using GRUB's device naming convention (@pxref{Naming
  24280. convention,,, grub, GNU GRUB manual}), for example:
  24281. @example
  24282. "(hd0,msdos1)/boot/vmlinuz"
  24283. @end example
  24284. If the device is specified explicitly as above, then the @code{device}
  24285. field is ignored entirely.
  24286. @item @code{linux-arguments} (default: @code{()})
  24287. The list of extra Linux kernel command-line arguments---e.g.,
  24288. @code{("console=ttyS0")}.
  24289. @item @code{initrd} (default: @code{#f})
  24290. A G-Expression or string denoting the file name of the initial RAM disk
  24291. to use (@pxref{G-Expressions}).
  24292. @item @code{device} (default: @code{#f})
  24293. The device where the kernel and initrd are to be found---i.e., for GRUB,
  24294. @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
  24295. This may be a file system label (a string), a file system UUID (a
  24296. bytevector, @pxref{File Systems}), or @code{#f}, in which case
  24297. the bootloader will search the device containing the file specified by
  24298. the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
  24299. must @emph{not} be an OS device name such as @file{/dev/sda1}.
  24300. @item @code{multiboot-kernel} (default: @code{#f})
  24301. The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
  24302. manual}). When this field is set, a Multiboot menu-entry is generated.
  24303. For example:
  24304. @lisp
  24305. (file-append mach "/boot/gnumach")
  24306. @end lisp
  24307. @item @code{multiboot-arguments} (default: @code{()})
  24308. The list of extra command-line arguments for the multiboot-kernel.
  24309. @item @code{multiboot-modules} (default: @code{()})
  24310. The list of commands for loading Multiboot modules. For example:
  24311. @lisp
  24312. (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
  24313. @dots{})
  24314. (list (file-append libc "/lib/ld.so.1") "exec"
  24315. @dots{}))
  24316. @end lisp
  24317. @end table
  24318. @end deftp
  24319. @cindex HDPI
  24320. @cindex HiDPI
  24321. @cindex resolution
  24322. @c FIXME: Write documentation once it's stable.
  24323. For now only GRUB has theme support. GRUB themes are created using
  24324. the @code{grub-theme} form, which is not fully documented yet.
  24325. @deftp {Data Type} grub-theme
  24326. Data type representing the configuration of the GRUB theme.
  24327. @table @asis
  24328. @item @code{gfxmode} (default: @code{'("auto")})
  24329. The GRUB @code{gfxmode} to set (a list of screen resolution strings,
  24330. @pxref{gfxmode,,, grub, GNU GRUB manual}).
  24331. @end table
  24332. @end deftp
  24333. @deffn {Scheme Procedure} grub-theme
  24334. Return the default GRUB theme used by the operating system if no
  24335. @code{theme} field is specified in @code{bootloader-configuration}
  24336. record.
  24337. It comes with a fancy background image displaying the GNU and Guix
  24338. logos.
  24339. @end deffn
  24340. For example, to override the default resolution, you may use something
  24341. like
  24342. @lisp
  24343. (bootloader
  24344. (bootloader-configuration
  24345. ;; @dots{}
  24346. (theme (grub-theme
  24347. (inherit (grub-theme))
  24348. (gfxmode '("1024x786x32" "auto"))))))
  24349. @end lisp
  24350. @node Invoking guix system
  24351. @section Invoking @code{guix system}
  24352. Once you have written an operating system declaration as seen in the
  24353. previous section, it can be @dfn{instantiated} using the @command{guix
  24354. system} command. The synopsis is:
  24355. @example
  24356. guix system @var{options}@dots{} @var{action} @var{file}
  24357. @end example
  24358. @var{file} must be the name of a file containing an
  24359. @code{operating-system} declaration. @var{action} specifies how the
  24360. operating system is instantiated. Currently the following values are
  24361. supported:
  24362. @table @code
  24363. @item search
  24364. Display available service type definitions that match the given regular
  24365. expressions, sorted by relevance:
  24366. @cindex HDPI
  24367. @cindex HiDPI
  24368. @cindex resolution
  24369. @example
  24370. $ guix system search console
  24371. name: console-fonts
  24372. location: gnu/services/base.scm:806:2
  24373. extends: shepherd-root
  24374. description: Install the given fonts on the specified ttys (fonts are per
  24375. + virtual console on GNU/Linux). The value of this service is a list of
  24376. + tty/font pairs. The font can be the name of a font provided by the `kbd'
  24377. + package or any valid argument to `setfont', as in this example:
  24378. +
  24379. + '(("tty1" . "LatGrkCyr-8x16")
  24380. + ("tty2" . (file-append
  24381. + font-tamzen
  24382. + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
  24383. + ("tty3" . (file-append
  24384. + font-terminus
  24385. + "/share/consolefonts/ter-132n"))) ; for HDPI
  24386. relevance: 9
  24387. name: mingetty
  24388. location: gnu/services/base.scm:1190:2
  24389. extends: shepherd-root
  24390. description: Provide console login using the `mingetty' program.
  24391. relevance: 2
  24392. name: login
  24393. location: gnu/services/base.scm:860:2
  24394. extends: pam
  24395. description: Provide a console log-in service as specified by its
  24396. + configuration value, a `login-configuration' object.
  24397. relevance: 2
  24398. @dots{}
  24399. @end example
  24400. As for @command{guix package --search}, the result is written in
  24401. @code{recutils} format, which makes it easy to filter the output
  24402. (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
  24403. @item reconfigure
  24404. Build the operating system described in @var{file}, activate it, and
  24405. switch to it@footnote{This action (and the related actions
  24406. @code{switch-generation} and @code{roll-back}) are usable only on
  24407. systems already running Guix System.}.
  24408. @quotation Note
  24409. @c The paragraph below refers to the problem discussed at
  24410. @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
  24411. It is highly recommended to run @command{guix pull} once before you run
  24412. @command{guix system reconfigure} for the first time (@pxref{Invoking
  24413. guix pull}). Failing to do that you would see an older version of Guix
  24414. once @command{reconfigure} has completed.
  24415. @end quotation
  24416. This effects all the configuration specified in @var{file}: user
  24417. accounts, system services, global package list, setuid programs, etc.
  24418. The command starts system services specified in @var{file} that are not
  24419. currently running; if a service is currently running this command will
  24420. arrange for it to be upgraded the next time it is stopped (e.g.@: by
  24421. @code{herd stop X} or @code{herd restart X}).
  24422. This command creates a new generation whose number is one greater than
  24423. the current generation (as reported by @command{guix system
  24424. list-generations}). If that generation already exists, it will be
  24425. overwritten. This behavior mirrors that of @command{guix package}
  24426. (@pxref{Invoking guix package}).
  24427. It also adds a bootloader menu entry for the new OS configuration,
  24428. ---unless @option{--no-bootloader} is passed. For GRUB, it moves
  24429. entries for older configurations to a submenu, allowing you to choose
  24430. an older system generation at boot time should you need it.
  24431. @cindex provenance tracking, of the operating system
  24432. Upon completion, the new system is deployed under
  24433. @file{/run/current-system}. This directory contains @dfn{provenance
  24434. meta-data}: the list of channels in use (@pxref{Channels}) and
  24435. @var{file} itself, when available. You can view it by running:
  24436. @example
  24437. guix system describe
  24438. @end example
  24439. This information is useful should you later want to inspect how this
  24440. particular generation was built. In fact, assuming @var{file} is
  24441. self-contained, you can later rebuild generation @var{n} of your
  24442. operating system with:
  24443. @example
  24444. guix time-machine \
  24445. -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
  24446. system reconfigure \
  24447. /var/guix/profiles/system-@var{n}-link/configuration.scm
  24448. @end example
  24449. You can think of it as some sort of built-in version control! Your
  24450. system is not just a binary artifact: @emph{it carries its own source}.
  24451. @xref{Service Reference, @code{provenance-service-type}}, for more
  24452. information on provenance tracking.
  24453. By default, @command{reconfigure} @emph{prevents you from downgrading
  24454. your system}, which could (re)introduce security vulnerabilities and
  24455. also cause problems with ``stateful'' services such as database
  24456. management systems. You can override that behavior by passing
  24457. @option{--allow-downgrades}.
  24458. @item switch-generation
  24459. @cindex generations
  24460. Switch to an existing system generation. This action atomically
  24461. switches the system profile to the specified system generation. It
  24462. also rearranges the system's existing bootloader menu entries. It
  24463. makes the menu entry for the specified system generation the default,
  24464. and it moves the entries for the other generations to a submenu, if
  24465. supported by the bootloader being used. The next time the system
  24466. boots, it will use the specified system generation.
  24467. The bootloader itself is not being reinstalled when using this
  24468. command. Thus, the installed bootloader is used with an updated
  24469. configuration file.
  24470. The target generation can be specified explicitly by its generation
  24471. number. For example, the following invocation would switch to system
  24472. generation 7:
  24473. @example
  24474. guix system switch-generation 7
  24475. @end example
  24476. The target generation can also be specified relative to the current
  24477. generation with the form @code{+N} or @code{-N}, where @code{+3} means
  24478. ``3 generations ahead of the current generation,'' and @code{-1} means
  24479. ``1 generation prior to the current generation.'' When specifying a
  24480. negative value such as @code{-1}, you must precede it with @code{--} to
  24481. prevent it from being parsed as an option. For example:
  24482. @example
  24483. guix system switch-generation -- -1
  24484. @end example
  24485. Currently, the effect of invoking this action is @emph{only} to switch
  24486. the system profile to an existing generation and rearrange the
  24487. bootloader menu entries. To actually start using the target system
  24488. generation, you must reboot after running this action. In the future,
  24489. it will be updated to do the same things as @command{reconfigure},
  24490. like activating and deactivating services.
  24491. This action will fail if the specified generation does not exist.
  24492. @item roll-back
  24493. @cindex rolling back
  24494. Switch to the preceding system generation. The next time the system
  24495. boots, it will use the preceding system generation. This is the inverse
  24496. of @command{reconfigure}, and it is exactly the same as invoking
  24497. @command{switch-generation} with an argument of @code{-1}.
  24498. Currently, as with @command{switch-generation}, you must reboot after
  24499. running this action to actually start using the preceding system
  24500. generation.
  24501. @item delete-generations
  24502. @cindex deleting system generations
  24503. @cindex saving space
  24504. Delete system generations, making them candidates for garbage collection
  24505. (@pxref{Invoking guix gc}, for information on how to run the ``garbage
  24506. collector'').
  24507. This works in the same way as @samp{guix package --delete-generations}
  24508. (@pxref{Invoking guix package, @option{--delete-generations}}). With no
  24509. arguments, all system generations but the current one are deleted:
  24510. @example
  24511. guix system delete-generations
  24512. @end example
  24513. You can also select the generations you want to delete. The example below
  24514. deletes all the system generations that are more than two month old:
  24515. @example
  24516. guix system delete-generations 2m
  24517. @end example
  24518. Running this command automatically reinstalls the bootloader with an updated
  24519. list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
  24520. longer lists the generations that have been deleted.
  24521. @item build
  24522. Build the derivation of the operating system, which includes all the
  24523. configuration files and programs needed to boot and run the system.
  24524. This action does not actually install anything.
  24525. @item init
  24526. Populate the given directory with all the files necessary to run the
  24527. operating system specified in @var{file}. This is useful for first-time
  24528. installations of Guix System. For instance:
  24529. @example
  24530. guix system init my-os-config.scm /mnt
  24531. @end example
  24532. copies to @file{/mnt} all the store items required by the configuration
  24533. specified in @file{my-os-config.scm}. This includes configuration
  24534. files, packages, and so on. It also creates other essential files
  24535. needed for the system to operate correctly---e.g., the @file{/etc},
  24536. @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
  24537. This command also installs bootloader on the target specified in
  24538. @file{my-os-config}, unless the @option{--no-bootloader} option was
  24539. passed.
  24540. @item vm
  24541. @cindex virtual machine
  24542. @cindex VM
  24543. @anchor{guix system vm}
  24544. Build a virtual machine that contains the operating system declared in
  24545. @var{file}, and return a script to run that virtual machine (VM).
  24546. @quotation Note
  24547. The @code{vm} action and others below
  24548. can use KVM support in the Linux-libre kernel. Specifically, if the
  24549. machine has hardware virtualization support, the corresponding
  24550. KVM kernel module should be loaded, and the @file{/dev/kvm} device node
  24551. must exist and be readable and writable by the user and by the
  24552. build users of the daemon (@pxref{Build Environment Setup}).
  24553. @end quotation
  24554. Arguments given to the script are passed to QEMU as in the example
  24555. below, which enables networking and requests 1@tie{}GiB of RAM for the
  24556. emulated machine:
  24557. @example
  24558. $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
  24559. @end example
  24560. The VM shares its store with the host system.
  24561. Additional file systems can be shared between the host and the VM using
  24562. the @option{--share} and @option{--expose} command-line options: the former
  24563. specifies a directory to be shared with write access, while the latter
  24564. provides read-only access to the shared directory.
  24565. The example below creates a VM in which the user's home directory is
  24566. accessible read-only, and where the @file{/exchange} directory is a
  24567. read-write mapping of @file{$HOME/tmp} on the host:
  24568. @example
  24569. guix system vm my-config.scm \
  24570. --expose=$HOME --share=$HOME/tmp=/exchange
  24571. @end example
  24572. On GNU/Linux, the default is to boot directly to the kernel; this has
  24573. the advantage of requiring only a very tiny root disk image since the
  24574. store of the host can then be mounted.
  24575. The @option{--full-boot} option forces a complete boot sequence, starting
  24576. with the bootloader. This requires more disk space since a root image
  24577. containing at least the kernel, initrd, and bootloader data files must
  24578. be created. The @option{--image-size} option can be used to specify the
  24579. size of the image.
  24580. @cindex System images, creation in various formats
  24581. @cindex Creating system images in various formats
  24582. @item vm-image
  24583. @itemx image
  24584. @itemx docker-image
  24585. Return a virtual machine, disk image, or Docker image of the operating
  24586. system declared in @var{file} that stands alone. By default,
  24587. @command{guix system} estimates the size of the image needed to store
  24588. the system, but you can use the @option{--image-size} option to specify
  24589. a value. Docker images are built to contain exactly what they need, so
  24590. the @option{--image-size} option is ignored in the case of
  24591. @code{docker-image}.
  24592. @cindex image, creating disk images
  24593. The @code{image} command can produce various image types. The
  24594. image type can be selected using the @option{--image-type} option. It
  24595. defaults to @code{efi-raw}. When its value is @code{iso9660}, the
  24596. @option{--label} option can be used to specify a volume ID with
  24597. @code{image}. By default, the root file system of a disk image is
  24598. mounted non-volatile; the @option{--volatile} option can be provided to
  24599. make it volatile instead. When using @code{image}, the bootloader
  24600. installed on the generated image is taken from the provided
  24601. @code{operating-system} definition. The following example demonstrates
  24602. how to generate an image that uses the @code{grub-efi-bootloader}
  24603. bootloader and boot it with QEMU:
  24604. @example
  24605. image=$(guix system image --image-type=qcow2 \
  24606. gnu/system/examples/lightweight-desktop.tmpl)
  24607. cp $image /tmp/my-image.qcow2
  24608. chmod +w /tmp/my-image.qcow2
  24609. qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
  24610. -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
  24611. @end example
  24612. When using the @code{efi-raw} image type, a raw disk image is produced;
  24613. it can be copied as is to a USB stick, for instance. Assuming
  24614. @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
  24615. the image to it using the following command:
  24616. @example
  24617. # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
  24618. @end example
  24619. The @code{--list-image-types} command lists all the available image
  24620. types.
  24621. @cindex vm-image, creating virtual machine images
  24622. When using @code{vm-image}, the returned image is in qcow2 format, which
  24623. the QEMU emulator can efficiently use. @xref{Running Guix in a VM}, for
  24624. more information on how to run the image in a virtual machine. The
  24625. @code{grub-bootloader} bootloader is always used independently of what
  24626. is declared in the @code{operating-system} file passed as argument.
  24627. This is to make it easier to work with QEMU, which uses the SeaBIOS BIOS
  24628. by default, expecting a bootloader to be installed in the Master Boot
  24629. Record (MBR).
  24630. @cindex docker-image, creating docker images
  24631. When using @code{docker-image}, a Docker image is produced. Guix builds
  24632. the image from scratch, not from a pre-existing Docker base image. As a
  24633. result, it contains @emph{exactly} what you define in the operating
  24634. system configuration file. You can then load the image and launch a
  24635. Docker container using commands like the following:
  24636. @example
  24637. image_id="`docker load < guix-system-docker-image.tar.gz`"
  24638. container_id="`docker create $image_id`"
  24639. docker start $container_id
  24640. @end example
  24641. This command starts a new Docker container from the specified image. It
  24642. will boot the Guix system in the usual manner, which means it will
  24643. start any services you have defined in the operating system
  24644. configuration. You can get an interactive shell running in the container
  24645. using @command{docker exec}:
  24646. @example
  24647. docker exec -ti $container_id /run/current-system/profile/bin/bash --login
  24648. @end example
  24649. Depending on what you run in the Docker container, it
  24650. may be necessary to give the container additional permissions. For
  24651. example, if you intend to build software using Guix inside of the Docker
  24652. container, you may need to pass the @option{--privileged} option to
  24653. @code{docker create}.
  24654. Last, the @option{--network} option applies to @command{guix system
  24655. docker-image}: it produces an image where network is supposedly shared
  24656. with the host, and thus without services like nscd or NetworkManager.
  24657. @item container
  24658. Return a script to run the operating system declared in @var{file}
  24659. within a container. Containers are a set of lightweight isolation
  24660. mechanisms provided by the kernel Linux-libre. Containers are
  24661. substantially less resource-demanding than full virtual machines since
  24662. the kernel, shared objects, and other resources can be shared with the
  24663. host system; this also means they provide thinner isolation.
  24664. Currently, the script must be run as root in order to support more than
  24665. a single user and group. The container shares its store with the host
  24666. system.
  24667. As with the @code{vm} action (@pxref{guix system vm}), additional file
  24668. systems to be shared between the host and container can be specified
  24669. using the @option{--share} and @option{--expose} options:
  24670. @example
  24671. guix system container my-config.scm \
  24672. --expose=$HOME --share=$HOME/tmp=/exchange
  24673. @end example
  24674. @quotation Note
  24675. This option requires Linux-libre 3.19 or newer.
  24676. @end quotation
  24677. @end table
  24678. @var{options} can contain any of the common build options (@pxref{Common
  24679. Build Options}). In addition, @var{options} can contain one of the
  24680. following:
  24681. @table @option
  24682. @item --expression=@var{expr}
  24683. @itemx -e @var{expr}
  24684. Consider the operating-system @var{expr} evaluates to.
  24685. This is an alternative to specifying a file which evaluates to an
  24686. operating system.
  24687. This is used to generate the Guix system installer @pxref{Building the
  24688. Installation Image}).
  24689. @item --system=@var{system}
  24690. @itemx -s @var{system}
  24691. Attempt to build for @var{system} instead of the host system type.
  24692. This works as per @command{guix build} (@pxref{Invoking guix build}).
  24693. @item --derivation
  24694. @itemx -d
  24695. Return the derivation file name of the given operating system without
  24696. building anything.
  24697. @cindex provenance tracking, of the operating system
  24698. @item --save-provenance
  24699. As discussed above, @command{guix system init} and @command{guix system
  24700. reconfigure} always save provenance information @i{via} a dedicated
  24701. service (@pxref{Service Reference, @code{provenance-service-type}}).
  24702. However, other commands don't do that by default. If you wish to, say,
  24703. create a virtual machine image that contains provenance information, you
  24704. can run:
  24705. @example
  24706. guix system vm-image --save-provenance config.scm
  24707. @end example
  24708. That way, the resulting image will effectively ``embed its own source''
  24709. in the form of meta-data in @file{/run/current-system}. With that
  24710. information, one can rebuild the image to make sure it really contains
  24711. what it pretends to contain; or they could use that to derive a variant
  24712. of the image.
  24713. @item --image-type=@var{type}
  24714. @itemx -t @var{type}
  24715. For the @code{image} action, create an image with given @var{type}.
  24716. When this option is omitted, @command{guix system} uses the
  24717. @code{efi-raw} image type.
  24718. @cindex ISO-9660 format
  24719. @cindex CD image format
  24720. @cindex DVD image format
  24721. @option{--image-type=iso9660} produces an ISO-9660 image, suitable
  24722. for burning on CDs and DVDs.
  24723. @item --image-size=@var{size}
  24724. For the @code{vm-image} and @code{image} actions, create an image
  24725. of the given @var{size}. @var{size} may be a number of bytes, or it may
  24726. include a unit as a suffix (@pxref{Block size, size specifications,,
  24727. coreutils, GNU Coreutils}).
  24728. When this option is omitted, @command{guix system} computes an estimate
  24729. of the image size as a function of the size of the system declared in
  24730. @var{file}.
  24731. @item --network
  24732. @itemx -N
  24733. For the @code{container} action, allow containers to access the host network,
  24734. that is, do not create a network namespace.
  24735. @item --root=@var{file}
  24736. @itemx -r @var{file}
  24737. Make @var{file} a symlink to the result, and register it as a garbage
  24738. collector root.
  24739. @item --skip-checks
  24740. Skip pre-installation safety checks.
  24741. By default, @command{guix system init} and @command{guix system
  24742. reconfigure} perform safety checks: they make sure the file systems that
  24743. appear in the @code{operating-system} declaration actually exist
  24744. (@pxref{File Systems}), and that any Linux kernel modules that may be
  24745. needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
  24746. RAM Disk}). Passing this option skips these tests altogether.
  24747. @item --allow-downgrades
  24748. Instruct @command{guix system reconfigure} to allow system downgrades.
  24749. By default, @command{reconfigure} prevents you from downgrading your
  24750. system. It achieves that by comparing the provenance info of your
  24751. system (shown by @command{guix system describe}) with that of your
  24752. @command{guix} command (shown by @command{guix describe}). If the
  24753. commits for @command{guix} are not descendants of those used for your
  24754. system, @command{guix system reconfigure} errors out. Passing
  24755. @option{--allow-downgrades} allows you to bypass these checks.
  24756. @quotation Note
  24757. Make sure you understand its security implications before using
  24758. @option{--allow-downgrades}.
  24759. @end quotation
  24760. @cindex on-error
  24761. @cindex on-error strategy
  24762. @cindex error strategy
  24763. @item --on-error=@var{strategy}
  24764. Apply @var{strategy} when an error occurs when reading @var{file}.
  24765. @var{strategy} may be one of the following:
  24766. @table @code
  24767. @item nothing-special
  24768. Report the error concisely and exit. This is the default strategy.
  24769. @item backtrace
  24770. Likewise, but also display a backtrace.
  24771. @item debug
  24772. Report the error and enter Guile's debugger. From there, you can run
  24773. commands such as @code{,bt} to get a backtrace, @code{,locals} to
  24774. display local variable values, and more generally inspect the state of the
  24775. program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
  24776. a list of available debugging commands.
  24777. @end table
  24778. @end table
  24779. Once you have built, configured, re-configured, and re-re-configured
  24780. your Guix installation, you may find it useful to list the operating
  24781. system generations available on disk---and that you can choose from the
  24782. bootloader boot menu:
  24783. @table @code
  24784. @item describe
  24785. Describe the current system generation: its file name, the kernel and
  24786. bootloader used, etc., as well as provenance information when available.
  24787. @item list-generations
  24788. List a summary of each generation of the operating system available on
  24789. disk, in a human-readable way. This is similar to the
  24790. @option{--list-generations} option of @command{guix package}
  24791. (@pxref{Invoking guix package}).
  24792. Optionally, one can specify a pattern, with the same syntax that is used
  24793. in @command{guix package --list-generations}, to restrict the list of
  24794. generations displayed. For instance, the following command displays
  24795. generations that are up to 10 days old:
  24796. @example
  24797. $ guix system list-generations 10d
  24798. @end example
  24799. @end table
  24800. The @command{guix system} command has even more to offer! The following
  24801. sub-commands allow you to visualize how your system services relate to
  24802. each other:
  24803. @anchor{system-extension-graph}
  24804. @table @code
  24805. @item extension-graph
  24806. Emit to standard output the @dfn{service
  24807. extension graph} of the operating system defined in @var{file}
  24808. (@pxref{Service Composition}, for more information on service
  24809. extensions). By default the output is in Dot/Graphviz format, but you
  24810. can choose a different format with @option{--graph-backend}, as with
  24811. @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
  24812. The command:
  24813. @example
  24814. $ guix system extension-graph @var{file} | xdot -
  24815. @end example
  24816. shows the extension relations among services.
  24817. @anchor{system-shepherd-graph}
  24818. @item shepherd-graph
  24819. Emit to standard output the @dfn{dependency
  24820. graph} of shepherd services of the operating system defined in
  24821. @var{file}. @xref{Shepherd Services}, for more information and for an
  24822. example graph.
  24823. Again, the default output format is Dot/Graphviz, but you can pass
  24824. @option{--graph-backend} to select a different one.
  24825. @end table
  24826. @node Invoking guix deploy
  24827. @section Invoking @code{guix deploy}
  24828. We've already seen @code{operating-system} declarations used to manage a
  24829. machine's configuration locally. Suppose you need to configure multiple
  24830. machines, though---perhaps you're managing a service on the web that's
  24831. comprised of several servers. @command{guix deploy} enables you to use those
  24832. same @code{operating-system} declarations to manage multiple remote hosts at
  24833. once as a logical ``deployment''.
  24834. @quotation Note
  24835. The functionality described in this section is still under development
  24836. and is subject to change. Get in touch with us on
  24837. @email{guix-devel@@gnu.org}!
  24838. @end quotation
  24839. @example
  24840. guix deploy @var{file}
  24841. @end example
  24842. Such an invocation will deploy the machines that the code within @var{file}
  24843. evaluates to. As an example, @var{file} might contain a definition like this:
  24844. @lisp
  24845. ;; This is a Guix deployment of a "bare bones" setup, with
  24846. ;; no X11 display server, to a machine with an SSH daemon
  24847. ;; listening on localhost:2222. A configuration such as this
  24848. ;; may be appropriate for virtual machine with ports
  24849. ;; forwarded to the host's loopback interface.
  24850. (use-service-modules networking ssh)
  24851. (use-package-modules bootloaders)
  24852. (define %system
  24853. (operating-system
  24854. (host-name "gnu-deployed")
  24855. (timezone "Etc/UTC")
  24856. (bootloader (bootloader-configuration
  24857. (bootloader grub-bootloader)
  24858. (target "/dev/vda")
  24859. (terminal-outputs '(console))))
  24860. (file-systems (cons (file-system
  24861. (mount-point "/")
  24862. (device "/dev/vda1")
  24863. (type "ext4"))
  24864. %base-file-systems))
  24865. (services
  24866. (append (list (service dhcp-client-service-type)
  24867. (service openssh-service-type
  24868. (openssh-configuration
  24869. (permit-root-login #t)
  24870. (allow-empty-passwords? #t))))
  24871. %base-services))))
  24872. (list (machine
  24873. (operating-system %system)
  24874. (environment managed-host-environment-type)
  24875. (configuration (machine-ssh-configuration
  24876. (host-name "localhost")
  24877. (system "x86_64-linux")
  24878. (user "alice")
  24879. (identity "./id_rsa")
  24880. (port 2222)))))
  24881. @end lisp
  24882. The file should evaluate to a list of @var{machine} objects. This example,
  24883. upon being deployed, will create a new generation on the remote system
  24884. realizing the @code{operating-system} declaration @code{%system}.
  24885. @code{environment} and @code{configuration} specify how the machine should be
  24886. provisioned---that is, how the computing resources should be created and
  24887. managed. The above example does not create any resources, as a
  24888. @code{'managed-host} is a machine that is already running the Guix system and
  24889. available over the network. This is a particularly simple case; a more
  24890. complex deployment may involve, for example, starting virtual machines through
  24891. a Virtual Private Server (VPS) provider. In such a case, a different
  24892. @var{environment} type would be used.
  24893. Do note that you first need to generate a key pair on the coordinator machine
  24894. to allow the daemon to export signed archives of files from the store
  24895. (@pxref{Invoking guix archive}), though this step is automatic on Guix
  24896. System:
  24897. @example
  24898. # guix archive --generate-key
  24899. @end example
  24900. @noindent
  24901. Each target machine must authorize the key of the master machine so that it
  24902. accepts store items it receives from the coordinator:
  24903. @example
  24904. # guix archive --authorize < coordinator-public-key.txt
  24905. @end example
  24906. @code{user}, in this example, specifies the name of the user account to log in
  24907. as to perform the deployment. Its default value is @code{root}, but root
  24908. login over SSH may be forbidden in some cases. To work around this,
  24909. @command{guix deploy} can log in as an unprivileged user and employ
  24910. @code{sudo} to escalate privileges. This will only work if @code{sudo} is
  24911. currently installed on the remote and can be invoked non-interactively as
  24912. @code{user}. That is, the line in @code{sudoers} granting @code{user} the
  24913. ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
  24914. be accomplished with the following operating system configuration snippet:
  24915. @lisp
  24916. (use-modules ...
  24917. (gnu system)) ;for %sudoers-specification
  24918. (define %user "username")
  24919. (operating-system
  24920. ...
  24921. (sudoers-file
  24922. (plain-file "sudoers"
  24923. (string-append (plain-file-content %sudoers-specification)
  24924. (format #f "~a ALL = NOPASSWD: ALL~%"
  24925. %user)))))
  24926. @end lisp
  24927. For more information regarding the format of the @file{sudoers} file,
  24928. consult @command{man sudoers}.
  24929. @deftp {Data Type} machine
  24930. This is the data type representing a single machine in a heterogeneous Guix
  24931. deployment.
  24932. @table @asis
  24933. @item @code{operating-system}
  24934. The object of the operating system configuration to deploy.
  24935. @item @code{environment}
  24936. An @code{environment-type} describing how the machine should be provisioned.
  24937. @item @code{configuration} (default: @code{#f})
  24938. An object describing the configuration for the machine's @code{environment}.
  24939. If the @code{environment} has a default configuration, @code{#f} may be used.
  24940. If @code{#f} is used for an environment with no default configuration,
  24941. however, an error will be thrown.
  24942. @end table
  24943. @end deftp
  24944. @deftp {Data Type} machine-ssh-configuration
  24945. This is the data type representing the SSH client parameters for a machine
  24946. with an @code{environment} of @code{managed-host-environment-type}.
  24947. @table @asis
  24948. @item @code{host-name}
  24949. @item @code{build-locally?} (default: @code{#t})
  24950. If false, system derivations will be built on the machine being deployed to.
  24951. @item @code{system}
  24952. The system type describing the architecture of the machine being deployed
  24953. to---e.g., @code{"x86_64-linux"}.
  24954. @item @code{authorize?} (default: @code{#t})
  24955. If true, the coordinator's signing key will be added to the remote's ACL
  24956. keyring.
  24957. @item @code{port} (default: @code{22})
  24958. @item @code{user} (default: @code{"root"})
  24959. @item @code{identity} (default: @code{#f})
  24960. If specified, the path to the SSH private key to use to authenticate with the
  24961. remote host.
  24962. @item @code{host-key} (default: @code{#f})
  24963. This should be the SSH host key of the machine, which looks like this:
  24964. @example
  24965. ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
  24966. @end example
  24967. When @code{host-key} is @code{#f}, the server is authenticated against
  24968. the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
  24969. client does.
  24970. @item @code{allow-downgrades?} (default: @code{#f})
  24971. Whether to allow potential downgrades.
  24972. Like @command{guix system reconfigure}, @command{guix deploy} compares
  24973. the channel commits currently deployed on the remote host (as returned
  24974. by @command{guix system describe}) to those currently in use (as
  24975. returned by @command{guix describe}) to determine whether commits
  24976. currently in use are descendants of those deployed. When this is not
  24977. the case and @code{allow-downgrades?} is false, it raises an error.
  24978. This ensures you do not accidentally downgrade remote machines.
  24979. @end table
  24980. @end deftp
  24981. @deftp {Data Type} digital-ocean-configuration
  24982. This is the data type describing the Droplet that should be created for a
  24983. machine with an @code{environment} of @code{digital-ocean-environment-type}.
  24984. @table @asis
  24985. @item @code{ssh-key}
  24986. The path to the SSH private key to use to authenticate with the remote
  24987. host. In the future, this field may not exist.
  24988. @item @code{tags}
  24989. A list of string ``tags'' that uniquely identify the machine. Must be given
  24990. such that no two machines in the deployment have the same set of tags.
  24991. @item @code{region}
  24992. A Digital Ocean region slug, such as @code{"nyc3"}.
  24993. @item @code{size}
  24994. A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
  24995. @item @code{enable-ipv6?}
  24996. Whether or not the droplet should be created with IPv6 networking.
  24997. @end table
  24998. @end deftp
  24999. @node Running Guix in a VM
  25000. @section Running Guix in a Virtual Machine
  25001. @cindex virtual machine
  25002. To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
  25003. distributed at
  25004. @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
  25005. This image is a compressed image in QCOW format. You will first need to
  25006. decompress with @command{xz -d}, and then you can pass it to an emulator such
  25007. as QEMU (see below for details).
  25008. This image boots the Xfce graphical environment and it contains some
  25009. commonly used tools. You can install more software in the image by running
  25010. @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
  25011. also reconfigure the system based on its initial configuration file available
  25012. as @file{/run/current-system/configuration.scm} (@pxref{Using the
  25013. Configuration System}).
  25014. Instead of using this pre-built image, one can also build their own virtual
  25015. machine image using @command{guix system vm-image} (@pxref{Invoking guix
  25016. system}). The returned image is in qcow2 format, which the
  25017. @uref{https://qemu.org/, QEMU emulator} can efficiently use.
  25018. @cindex QEMU
  25019. If you built your own image, you must copy it out of the store
  25020. (@pxref{The Store}) and give yourself permission to write to the copy
  25021. before you can use it. When invoking QEMU, you must choose a system
  25022. emulator that is suitable for your hardware platform. Here is a minimal
  25023. QEMU invocation that will boot the result of @command{guix system
  25024. vm-image} on x86_64 hardware:
  25025. @example
  25026. $ qemu-system-x86_64 \
  25027. -nic user,model=virtio-net-pci \
  25028. -enable-kvm -m 1024 \
  25029. -device virtio-blk,drive=myhd \
  25030. -drive if=none,file=/tmp/qemu-image,id=myhd
  25031. @end example
  25032. Here is what each of these options means:
  25033. @table @code
  25034. @item qemu-system-x86_64
  25035. This specifies the hardware platform to emulate. This should match the
  25036. host.
  25037. @item -nic user,model=virtio-net-pci
  25038. Enable the unprivileged user-mode network stack. The guest OS can
  25039. access the host but not vice versa. This is the simplest way to get the
  25040. guest OS online. @code{model} specifies which network device to emulate:
  25041. @code{virtio-net-pci} is a special device made for virtualized operating
  25042. systems and recommended for most uses. Assuming your hardware platform is
  25043. x86_64, you can get a list of available NIC models by running
  25044. @command{qemu-system-x86_64 -nic model=help}.
  25045. @item -enable-kvm
  25046. If your system has hardware virtualization extensions, enabling the
  25047. virtual machine support (KVM) of the Linux kernel will make things run
  25048. faster.
  25049. @c To run Xfce + 'guix pull', we need at least 1G of RAM.
  25050. @item -m 1024
  25051. RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
  25052. which may be insufficient for some operations.
  25053. @item -device virtio-blk,drive=myhd
  25054. Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
  25055. ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
  25056. better performance than if it were emulating a complete disk drive. See the
  25057. QEMU and KVM documentation for more info.
  25058. @item -drive if=none,file=/tmp/qemu-image,id=myhd
  25059. Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
  25060. store of the ``myhd'' drive.
  25061. @end table
  25062. The default @command{run-vm.sh} script that is returned by an invocation of
  25063. @command{guix system vm} does not add a @command{-nic user} flag by default.
  25064. To get network access from within the vm add the @code{(dhcp-client-service)}
  25065. to your system definition and start the VM using
  25066. @command{`guix system vm config.scm` -nic user}. An important caveat of using
  25067. @command{-nic user} for networking is that @command{ping} will not work, because
  25068. it uses the ICMP protocol. You'll have to use a different command to check for
  25069. network connectivity, for example @command{guix download}.
  25070. @subsection Connecting Through SSH
  25071. @cindex SSH
  25072. @cindex SSH server
  25073. To enable SSH inside a VM you need to add an SSH server like
  25074. @code{openssh-service-type} to your VM (@pxref{Networking Services,
  25075. @code{openssh-service-type}}). In addition you need to forward the SSH port,
  25076. 22 by default, to the host. You can do this with
  25077. @example
  25078. `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
  25079. @end example
  25080. To connect to the VM you can run
  25081. @example
  25082. ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
  25083. @end example
  25084. The @command{-p} tells @command{ssh} the port you want to connect to.
  25085. @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
  25086. every time you modify your @command{config.scm} file and the
  25087. @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
  25088. connection to an unknown host every time you connect.
  25089. @subsection Using @command{virt-viewer} with Spice
  25090. As an alternative to the default @command{qemu} graphical client you can
  25091. use the @command{remote-viewer} from the @command{virt-viewer} package. To
  25092. connect pass the @command{-spice port=5930,disable-ticketing} flag to
  25093. @command{qemu}. See previous section for further information on how to do this.
  25094. Spice also allows you to do some nice stuff like share your clipboard with your
  25095. VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
  25096. @example
  25097. -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
  25098. -chardev spicevmc,name=vdagent,id=vdagent
  25099. -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
  25100. name=com.redhat.spice.0
  25101. @end example
  25102. You'll also need to add the @code{(spice-vdagent-service)} to your
  25103. system definition (@pxref{Miscellaneous Services, Spice service}).
  25104. @node Defining Services
  25105. @section Defining Services
  25106. The previous sections show the available services and how one can combine
  25107. them in an @code{operating-system} declaration. But how do we define
  25108. them in the first place? And what is a service anyway?
  25109. @menu
  25110. * Service Composition:: The model for composing services.
  25111. * Service Types and Services:: Types and services.
  25112. * Service Reference:: API reference.
  25113. * Shepherd Services:: A particular type of service.
  25114. @end menu
  25115. @node Service Composition
  25116. @subsection Service Composition
  25117. @cindex services
  25118. @cindex daemons
  25119. Here we define a @dfn{service} as, broadly, something that extends the
  25120. functionality of the operating system. Often a service is a process---a
  25121. @dfn{daemon}---started when the system boots: a secure shell server, a
  25122. Web server, the Guix build daemon, etc. Sometimes a service is a daemon
  25123. whose execution can be triggered by another daemon---e.g., an FTP server
  25124. started by @command{inetd} or a D-Bus service activated by
  25125. @command{dbus-daemon}. Occasionally, a service does not map to a
  25126. daemon. For instance, the ``account'' service collects user accounts
  25127. and makes sure they exist when the system runs; the ``udev'' service
  25128. collects device management rules and makes them available to the eudev
  25129. daemon; the @file{/etc} service populates the @file{/etc} directory
  25130. of the system.
  25131. @cindex service extensions
  25132. Guix system services are connected by @dfn{extensions}. For instance, the
  25133. secure shell service @emph{extends} the Shepherd---the
  25134. initialization system, running as PID@tie{}1---by giving it the command
  25135. lines to start and stop the secure shell daemon (@pxref{Networking
  25136. Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
  25137. service by passing it its @file{.service} specification, and extends the
  25138. udev service by passing it device management rules (@pxref{Desktop
  25139. Services, @code{upower-service}}); the Guix daemon service extends the
  25140. Shepherd by passing it the command lines to start and stop the daemon,
  25141. and extends the account service by passing it a list of required build
  25142. user accounts (@pxref{Base Services}).
  25143. All in all, services and their ``extends'' relations form a directed
  25144. acyclic graph (DAG). If we represent services as boxes and extensions
  25145. as arrows, a typical system might provide something like this:
  25146. @image{images/service-graph,,5in,Typical service extension graph.}
  25147. @cindex system service
  25148. At the bottom, we see the @dfn{system service}, which produces the
  25149. directory containing everything to run and boot the system, as returned
  25150. by the @command{guix system build} command. @xref{Service Reference},
  25151. to learn about the other service types shown here.
  25152. @xref{system-extension-graph, the @command{guix system extension-graph}
  25153. command}, for information on how to generate this representation for a
  25154. particular operating system definition.
  25155. @cindex service types
  25156. Technically, developers can define @dfn{service types} to express these
  25157. relations. There can be any number of services of a given type on the
  25158. system---for instance, a system running two instances of the GNU secure
  25159. shell server (lsh) has two instances of @code{lsh-service-type}, with
  25160. different parameters.
  25161. The following section describes the programming interface for service
  25162. types and services.
  25163. @node Service Types and Services
  25164. @subsection Service Types and Services
  25165. A @dfn{service type} is a node in the DAG described above. Let us start
  25166. with a simple example, the service type for the Guix build daemon
  25167. (@pxref{Invoking guix-daemon}):
  25168. @lisp
  25169. (define guix-service-type
  25170. (service-type
  25171. (name 'guix)
  25172. (extensions
  25173. (list (service-extension shepherd-root-service-type guix-shepherd-service)
  25174. (service-extension account-service-type guix-accounts)
  25175. (service-extension activation-service-type guix-activation)))
  25176. (default-value (guix-configuration))))
  25177. @end lisp
  25178. @noindent
  25179. It defines three things:
  25180. @enumerate
  25181. @item
  25182. A name, whose sole purpose is to make inspection and debugging easier.
  25183. @item
  25184. A list of @dfn{service extensions}, where each extension designates the
  25185. target service type and a procedure that, given the parameters of the
  25186. service, returns a list of objects to extend the service of that type.
  25187. Every service type has at least one service extension. The only
  25188. exception is the @dfn{boot service type}, which is the ultimate service.
  25189. @item
  25190. Optionally, a default value for instances of this type.
  25191. @end enumerate
  25192. In this example, @code{guix-service-type} extends three services:
  25193. @table @code
  25194. @item shepherd-root-service-type
  25195. The @code{guix-shepherd-service} procedure defines how the Shepherd
  25196. service is extended. Namely, it returns a @code{<shepherd-service>}
  25197. object that defines how @command{guix-daemon} is started and stopped
  25198. (@pxref{Shepherd Services}).
  25199. @item account-service-type
  25200. This extension for this service is computed by @code{guix-accounts},
  25201. which returns a list of @code{user-group} and @code{user-account}
  25202. objects representing the build user accounts (@pxref{Invoking
  25203. guix-daemon}).
  25204. @item activation-service-type
  25205. Here @code{guix-activation} is a procedure that returns a gexp, which is
  25206. a code snippet to run at ``activation time''---e.g., when the service is
  25207. booted.
  25208. @end table
  25209. A service of this type is instantiated like this:
  25210. @lisp
  25211. (service guix-service-type
  25212. (guix-configuration
  25213. (build-accounts 5)
  25214. (extra-options '("--gc-keep-derivations"))))
  25215. @end lisp
  25216. The second argument to the @code{service} form is a value representing
  25217. the parameters of this specific service instance.
  25218. @xref{guix-configuration-type, @code{guix-configuration}}, for
  25219. information about the @code{guix-configuration} data type. When the
  25220. value is omitted, the default value specified by
  25221. @code{guix-service-type} is used:
  25222. @lisp
  25223. (service guix-service-type)
  25224. @end lisp
  25225. @code{guix-service-type} is quite simple because it extends other
  25226. services but is not extensible itself.
  25227. @c @subsubsubsection Extensible Service Types
  25228. The service type for an @emph{extensible} service looks like this:
  25229. @lisp
  25230. (define udev-service-type
  25231. (service-type (name 'udev)
  25232. (extensions
  25233. (list (service-extension shepherd-root-service-type
  25234. udev-shepherd-service)))
  25235. (compose concatenate) ;concatenate the list of rules
  25236. (extend (lambda (config rules)
  25237. (match config
  25238. (($ <udev-configuration> udev initial-rules)
  25239. (udev-configuration
  25240. (udev udev) ;the udev package to use
  25241. (rules (append initial-rules rules)))))))))
  25242. @end lisp
  25243. This is the service type for the
  25244. @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
  25245. management daemon}. Compared to the previous example, in addition to an
  25246. extension of @code{shepherd-root-service-type}, we see two new fields:
  25247. @table @code
  25248. @item compose
  25249. This is the procedure to @dfn{compose} the list of extensions to
  25250. services of this type.
  25251. Services can extend the udev service by passing it lists of rules; we
  25252. compose those extensions simply by concatenating them.
  25253. @item extend
  25254. This procedure defines how the value of the service is @dfn{extended} with
  25255. the composition of the extensions.
  25256. Udev extensions are composed into a list of rules, but the udev service
  25257. value is itself a @code{<udev-configuration>} record. So here, we
  25258. extend that record by appending the list of rules it contains to the
  25259. list of contributed rules.
  25260. @item description
  25261. This is a string giving an overview of the service type. The string can
  25262. contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
  25263. @command{guix system search} command searches these strings and displays
  25264. them (@pxref{Invoking guix system}).
  25265. @end table
  25266. There can be only one instance of an extensible service type such as
  25267. @code{udev-service-type}. If there were more, the
  25268. @code{service-extension} specifications would be ambiguous.
  25269. Still here? The next section provides a reference of the programming
  25270. interface for services.
  25271. @node Service Reference
  25272. @subsection Service Reference
  25273. We have seen an overview of service types (@pxref{Service Types and
  25274. Services}). This section provides a reference on how to manipulate
  25275. services and service types. This interface is provided by the
  25276. @code{(gnu services)} module.
  25277. @deffn {Scheme Procedure} service @var{type} [@var{value}]
  25278. Return a new service of @var{type}, a @code{<service-type>} object (see
  25279. below). @var{value} can be any object; it represents the parameters of
  25280. this particular service instance.
  25281. When @var{value} is omitted, the default value specified by @var{type}
  25282. is used; if @var{type} does not specify a default value, an error is
  25283. raised.
  25284. For instance, this:
  25285. @lisp
  25286. (service openssh-service-type)
  25287. @end lisp
  25288. @noindent
  25289. is equivalent to this:
  25290. @lisp
  25291. (service openssh-service-type
  25292. (openssh-configuration))
  25293. @end lisp
  25294. In both cases the result is an instance of @code{openssh-service-type}
  25295. with the default configuration.
  25296. @end deffn
  25297. @deffn {Scheme Procedure} service? @var{obj}
  25298. Return true if @var{obj} is a service.
  25299. @end deffn
  25300. @deffn {Scheme Procedure} service-kind @var{service}
  25301. Return the type of @var{service}---i.e., a @code{<service-type>} object.
  25302. @end deffn
  25303. @deffn {Scheme Procedure} service-value @var{service}
  25304. Return the value associated with @var{service}. It represents its
  25305. parameters.
  25306. @end deffn
  25307. Here is an example of how a service is created and manipulated:
  25308. @lisp
  25309. (define s
  25310. (service nginx-service-type
  25311. (nginx-configuration
  25312. (nginx nginx)
  25313. (log-directory log-directory)
  25314. (run-directory run-directory)
  25315. (file config-file))))
  25316. (service? s)
  25317. @result{} #t
  25318. (eq? (service-kind s) nginx-service-type)
  25319. @result{} #t
  25320. @end lisp
  25321. The @code{modify-services} form provides a handy way to change the
  25322. parameters of some of the services of a list such as
  25323. @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
  25324. evaluates to a list of services. Of course, you could always use
  25325. standard list combinators such as @code{map} and @code{fold} to do that
  25326. (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
  25327. @code{modify-services} simply provides a more concise form for this
  25328. common pattern.
  25329. @deffn {Scheme Syntax} modify-services @var{services} @
  25330. (@var{type} @var{variable} => @var{body}) @dots{}
  25331. Modify the services listed in @var{services} according to the given
  25332. clauses. Each clause has the form:
  25333. @example
  25334. (@var{type} @var{variable} => @var{body})
  25335. @end example
  25336. where @var{type} is a service type---e.g.,
  25337. @code{guix-service-type}---and @var{variable} is an identifier that is
  25338. bound within the @var{body} to the service parameters---e.g., a
  25339. @code{guix-configuration} instance---of the original service of that
  25340. @var{type}.
  25341. The @var{body} should evaluate to the new service parameters, which will
  25342. be used to configure the new service. This new service will replace the
  25343. original in the resulting list. Because a service's service parameters
  25344. are created using @code{define-record-type*}, you can write a succinct
  25345. @var{body} that evaluates to the new service parameters by using the
  25346. @code{inherit} feature that @code{define-record-type*} provides.
  25347. @xref{Using the Configuration System}, for example usage.
  25348. @end deffn
  25349. Next comes the programming interface for service types. This is
  25350. something you want to know when writing new service definitions, but not
  25351. necessarily when simply looking for ways to customize your
  25352. @code{operating-system} declaration.
  25353. @deftp {Data Type} service-type
  25354. @cindex service type
  25355. This is the representation of a @dfn{service type} (@pxref{Service Types
  25356. and Services}).
  25357. @table @asis
  25358. @item @code{name}
  25359. This is a symbol, used only to simplify inspection and debugging.
  25360. @item @code{extensions}
  25361. A non-empty list of @code{<service-extension>} objects (see below).
  25362. @item @code{compose} (default: @code{#f})
  25363. If this is @code{#f}, then the service type denotes services that cannot
  25364. be extended---i.e., services that do not receive ``values'' from other
  25365. services.
  25366. Otherwise, it must be a one-argument procedure. The procedure is called
  25367. by @code{fold-services} and is passed a list of values collected from
  25368. extensions. It may return any single value.
  25369. @item @code{extend} (default: @code{#f})
  25370. If this is @code{#f}, services of this type cannot be extended.
  25371. Otherwise, it must be a two-argument procedure: @code{fold-services}
  25372. calls it, passing it the initial value of the service as the first
  25373. argument and the result of applying @code{compose} to the extension
  25374. values as the second argument. It must return a value that is a valid
  25375. parameter value for the service instance.
  25376. @item @code{description}
  25377. This is a string, possibly using Texinfo markup, describing in a couple
  25378. of sentences what the service is about. This string allows users to
  25379. find about the service through @command{guix system search}
  25380. (@pxref{Invoking guix system}).
  25381. @item @code{default-value} (default: @code{&no-default-value})
  25382. The default value associated for instances of this service type. This
  25383. allows users to use the @code{service} form without its second argument:
  25384. @lisp
  25385. (service @var{type})
  25386. @end lisp
  25387. The returned service in this case has the default value specified by
  25388. @var{type}.
  25389. @end table
  25390. @xref{Service Types and Services}, for examples.
  25391. @end deftp
  25392. @deffn {Scheme Procedure} service-extension @var{target-type} @
  25393. @var{compute}
  25394. Return a new extension for services of type @var{target-type}.
  25395. @var{compute} must be a one-argument procedure: @code{fold-services}
  25396. calls it, passing it the value associated with the service that provides
  25397. the extension; it must return a valid value for the target service.
  25398. @end deffn
  25399. @deffn {Scheme Procedure} service-extension? @var{obj}
  25400. Return true if @var{obj} is a service extension.
  25401. @end deffn
  25402. Occasionally, you might want to simply extend an existing service. This
  25403. involves creating a new service type and specifying the extension of
  25404. interest, which can be verbose; the @code{simple-service} procedure
  25405. provides a shorthand for this.
  25406. @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
  25407. Return a service that extends @var{target} with @var{value}. This works
  25408. by creating a singleton service type @var{name}, of which the returned
  25409. service is an instance.
  25410. For example, this extends mcron (@pxref{Scheduled Job Execution}) with
  25411. an additional job:
  25412. @lisp
  25413. (simple-service 'my-mcron-job mcron-service-type
  25414. #~(job '(next-hour (3)) "guix gc -F 2G"))
  25415. @end lisp
  25416. @end deffn
  25417. At the core of the service abstraction lies the @code{fold-services}
  25418. procedure, which is responsible for ``compiling'' a list of services
  25419. down to a single directory that contains everything needed to boot and
  25420. run the system---the directory shown by the @command{guix system build}
  25421. command (@pxref{Invoking guix system}). In essence, it propagates
  25422. service extensions down the service graph, updating each node parameters
  25423. on the way, until it reaches the root node.
  25424. @deffn {Scheme Procedure} fold-services @var{services} @
  25425. [#:target-type @var{system-service-type}]
  25426. Fold @var{services} by propagating their extensions down to the root of
  25427. type @var{target-type}; return the root service adjusted accordingly.
  25428. @end deffn
  25429. Lastly, the @code{(gnu services)} module also defines several essential
  25430. service types, some of which are listed below.
  25431. @defvr {Scheme Variable} system-service-type
  25432. This is the root of the service graph. It produces the system directory
  25433. as returned by the @command{guix system build} command.
  25434. @end defvr
  25435. @defvr {Scheme Variable} boot-service-type
  25436. The type of the ``boot service'', which produces the @dfn{boot script}.
  25437. The boot script is what the initial RAM disk runs when booting.
  25438. @end defvr
  25439. @defvr {Scheme Variable} etc-service-type
  25440. The type of the @file{/etc} service. This service is used to create
  25441. files under @file{/etc} and can be extended by
  25442. passing it name/file tuples such as:
  25443. @lisp
  25444. (list `("issue" ,(plain-file "issue" "Welcome!\n")))
  25445. @end lisp
  25446. In this example, the effect would be to add an @file{/etc/issue} file
  25447. pointing to the given file.
  25448. @end defvr
  25449. @defvr {Scheme Variable} setuid-program-service-type
  25450. Type for the ``setuid-program service''. This service collects lists of
  25451. executable file names, passed as gexps, and adds them to the set of
  25452. setuid-root programs on the system (@pxref{Setuid Programs}).
  25453. @end defvr
  25454. @defvr {Scheme Variable} profile-service-type
  25455. Type of the service that populates the @dfn{system profile}---i.e., the
  25456. programs under @file{/run/current-system/profile}. Other services can
  25457. extend it by passing it lists of packages to add to the system profile.
  25458. @end defvr
  25459. @cindex provenance tracking, of the operating system
  25460. @anchor{provenance-service-type}
  25461. @defvr {Scheme Variable} provenance-service-type
  25462. This is the type of the service that records @dfn{provenance meta-data}
  25463. in the system itself. It creates several files under
  25464. @file{/run/current-system}:
  25465. @table @file
  25466. @item channels.scm
  25467. This is a ``channel file'' that can be passed to @command{guix pull -C}
  25468. or @command{guix time-machine -C}, and which describes the channels used
  25469. to build the system, if that information was available
  25470. (@pxref{Channels}).
  25471. @item configuration.scm
  25472. This is the file that was passed as the value for this
  25473. @code{provenance-service-type} service. By default, @command{guix
  25474. system reconfigure} automatically passes the OS configuration file it
  25475. received on the command line.
  25476. @item provenance
  25477. This contains the same information as the two other files but in a
  25478. format that is more readily processable.
  25479. @end table
  25480. In general, these two pieces of information (channels and configuration
  25481. file) are enough to reproduce the operating system ``from source''.
  25482. @quotation Caveats
  25483. This information is necessary to rebuild your operating system, but it
  25484. is not always sufficient. In particular, @file{configuration.scm}
  25485. itself is insufficient if it is not self-contained---if it refers to
  25486. external Guile modules or to extra files. If you want
  25487. @file{configuration.scm} to be self-contained, we recommend that modules
  25488. or files it refers to be part of a channel.
  25489. Besides, provenance meta-data is ``silent'' in the sense that it does
  25490. not change the bits contained in your system, @emph{except for the
  25491. meta-data bits themselves}. Two different OS configurations or sets of
  25492. channels can lead to the same system, bit-for-bit; when
  25493. @code{provenance-service-type} is used, these two systems will have
  25494. different meta-data and thus different store file names, which makes
  25495. comparison less trivial.
  25496. @end quotation
  25497. This service is automatically added to your operating system
  25498. configuration when you use @command{guix system reconfigure},
  25499. @command{guix system init}, or @command{guix deploy}.
  25500. @end defvr
  25501. @node Shepherd Services
  25502. @subsection Shepherd Services
  25503. @cindex shepherd services
  25504. @cindex PID 1
  25505. @cindex init system
  25506. The @code{(gnu services shepherd)} module provides a way to define
  25507. services managed by the GNU@tie{}Shepherd, which is the
  25508. initialization system---the first process that is started when the
  25509. system boots, also known as PID@tie{}1
  25510. (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
  25511. Services in the Shepherd can depend on each other. For instance, the
  25512. SSH daemon may need to be started after the syslog daemon has been
  25513. started, which in turn can only happen once all the file systems have
  25514. been mounted. The simple operating system defined earlier (@pxref{Using
  25515. the Configuration System}) results in a service graph like this:
  25516. @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
  25517. You can actually generate such a graph for any operating system
  25518. definition using the @command{guix system shepherd-graph} command
  25519. (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
  25520. The @code{%shepherd-root-service} is a service object representing
  25521. PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
  25522. by passing it lists of @code{<shepherd-service>} objects.
  25523. @deftp {Data Type} shepherd-service
  25524. The data type representing a service managed by the Shepherd.
  25525. @table @asis
  25526. @item @code{provision}
  25527. This is a list of symbols denoting what the service provides.
  25528. These are the names that may be passed to @command{herd start},
  25529. @command{herd status}, and similar commands (@pxref{Invoking herd,,,
  25530. shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
  25531. @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
  25532. @item @code{requirement} (default: @code{'()})
  25533. List of symbols denoting the Shepherd services this one depends on.
  25534. @cindex one-shot services, for the Shepherd
  25535. @item @code{one-shot?} (default: @code{#f})
  25536. Whether this service is @dfn{one-shot}. One-shot services stop immediately
  25537. after their @code{start} action has completed. @xref{Slots of services,,,
  25538. shepherd, The GNU Shepherd Manual}, for more info.
  25539. @item @code{respawn?} (default: @code{#t})
  25540. Whether to restart the service when it stops, for instance when the
  25541. underlying process dies.
  25542. @item @code{start}
  25543. @itemx @code{stop} (default: @code{#~(const #f)})
  25544. The @code{start} and @code{stop} fields refer to the Shepherd's
  25545. facilities to start and stop processes (@pxref{Service De- and
  25546. Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
  25547. G-expressions that get expanded in the Shepherd configuration file
  25548. (@pxref{G-Expressions}).
  25549. @item @code{actions} (default: @code{'()})
  25550. @cindex actions, of Shepherd services
  25551. This is a list of @code{shepherd-action} objects (see below) defining
  25552. @dfn{actions} supported by the service, in addition to the standard
  25553. @code{start} and @code{stop} actions. Actions listed here become available as
  25554. @command{herd} sub-commands:
  25555. @example
  25556. herd @var{action} @var{service} [@var{arguments}@dots{}]
  25557. @end example
  25558. @item @code{auto-start?} (default: @code{#t})
  25559. Whether this service should be started automatically by the Shepherd. If it
  25560. is @code{#f} the service has to be started manually with @code{herd start}.
  25561. @item @code{documentation}
  25562. A documentation string, as shown when running:
  25563. @example
  25564. herd doc @var{service-name}
  25565. @end example
  25566. where @var{service-name} is one of the symbols in @code{provision}
  25567. (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
  25568. @item @code{modules} (default: @code{%default-modules})
  25569. This is the list of modules that must be in scope when @code{start} and
  25570. @code{stop} are evaluated.
  25571. @end table
  25572. @end deftp
  25573. @deftp {Data Type} shepherd-action
  25574. This is the data type that defines additional actions implemented by a
  25575. Shepherd service (see above).
  25576. @table @code
  25577. @item name
  25578. Symbol naming the action.
  25579. @item documentation
  25580. This is a documentation string for the action. It can be viewed by running:
  25581. @example
  25582. herd doc @var{service} action @var{action}
  25583. @end example
  25584. @item procedure
  25585. This should be a gexp that evaluates to a procedure of at least one argument,
  25586. which is the ``running value'' of the service (@pxref{Slots of services,,,
  25587. shepherd, The GNU Shepherd Manual}).
  25588. @end table
  25589. The following example defines an action called @code{say-hello} that kindly
  25590. greets the user:
  25591. @lisp
  25592. (shepherd-action
  25593. (name 'say-hello)
  25594. (documentation "Say hi!")
  25595. (procedure #~(lambda (running . args)
  25596. (format #t "Hello, friend! arguments: ~s\n"
  25597. args)
  25598. #t)))
  25599. @end lisp
  25600. Assuming this action is added to the @code{example} service, then you can do:
  25601. @example
  25602. # herd say-hello example
  25603. Hello, friend! arguments: ()
  25604. # herd say-hello example a b c
  25605. Hello, friend! arguments: ("a" "b" "c")
  25606. @end example
  25607. This, as you can see, is a fairly sophisticated way to say hello.
  25608. @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
  25609. info on actions.
  25610. @end deftp
  25611. @defvr {Scheme Variable} shepherd-root-service-type
  25612. The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
  25613. This is the service type that extensions target when they want to create
  25614. shepherd services (@pxref{Service Types and Services}, for an example).
  25615. Each extension must pass a list of @code{<shepherd-service>}. Its
  25616. value must be a @code{shepherd-configuration}, as described below.
  25617. @end defvr
  25618. @deftp {Data Type} shepherd-configuration
  25619. This data type represents the Shepherd's configuration.
  25620. @table @code
  25621. @item shepherd (default: @code{shepherd})
  25622. The Shepherd package to use.
  25623. @item services (default: @code{'()})
  25624. A list of @code{<shepherd-service>} to start.
  25625. You should probably use the service extension
  25626. mechanism instead (@pxref{Shepherd Services}).
  25627. @end table
  25628. @end deftp
  25629. @defvr {Scheme Variable} %shepherd-root-service
  25630. This service represents PID@tie{}1.
  25631. @end defvr
  25632. @node Documentation
  25633. @chapter Documentation
  25634. @cindex documentation, searching for
  25635. @cindex searching for documentation
  25636. @cindex Info, documentation format
  25637. @cindex man pages
  25638. @cindex manual pages
  25639. In most cases packages installed with Guix come with documentation.
  25640. There are two main documentation formats: ``Info'', a browseable
  25641. hypertext format used for GNU software, and ``manual pages'' (or ``man
  25642. pages''), the linear documentation format traditionally found on Unix.
  25643. Info manuals are accessed with the @command{info} command or with Emacs,
  25644. and man pages are accessed using @command{man}.
  25645. You can look for documentation of software installed on your system by
  25646. keyword. For example, the following command searches for information
  25647. about ``TLS'' in Info manuals:
  25648. @example
  25649. $ info -k TLS
  25650. "(emacs)Network Security" -- STARTTLS
  25651. "(emacs)Network Security" -- TLS
  25652. "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
  25653. "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
  25654. @dots{}
  25655. @end example
  25656. @noindent
  25657. The command below searches for the same keyword in man pages:
  25658. @example
  25659. $ man -k TLS
  25660. SSL (7) - OpenSSL SSL/TLS library
  25661. certtool (1) - GnuTLS certificate tool
  25662. @dots {}
  25663. @end example
  25664. These searches are purely local to your computer so you have the
  25665. guarantee that documentation you find corresponds to what you have
  25666. actually installed, you can access it off-line, and your privacy is
  25667. respected.
  25668. Once you have these results, you can view the relevant documentation by
  25669. running, say:
  25670. @example
  25671. $ info "(gnutls)Core TLS API"
  25672. @end example
  25673. @noindent
  25674. or:
  25675. @example
  25676. $ man certtool
  25677. @end example
  25678. Info manuals contain sections and indices as well as hyperlinks like
  25679. those found in Web pages. The @command{info} reader (@pxref{Top, Info
  25680. reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
  25681. (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
  25682. bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
  25683. Introduction}, for an introduction to Info navigation.
  25684. @node Installing Debugging Files
  25685. @chapter Installing Debugging Files
  25686. @cindex debugging files
  25687. Program binaries, as produced by the GCC compilers for instance, are
  25688. typically written in the ELF format, with a section containing
  25689. @dfn{debugging information}. Debugging information is what allows the
  25690. debugger, GDB, to map binary code to source code; it is required to
  25691. debug a compiled program in good conditions.
  25692. This chapter explains how to use separate debug info when packages
  25693. provide it, and how to rebuild packages with debug info when it's
  25694. missing.
  25695. @menu
  25696. * Separate Debug Info:: Installing 'debug' outputs.
  25697. * Rebuilding Debug Info:: Building missing debug info.
  25698. @end menu
  25699. @node Separate Debug Info
  25700. @section Separate Debug Info
  25701. The problem with debugging information is that is takes up a fair amount
  25702. of disk space. For example, debugging information for the GNU C Library
  25703. weighs in at more than 60 MiB@. Thus, as a user, keeping all the
  25704. debugging info of all the installed programs is usually not an option.
  25705. Yet, space savings should not come at the cost of an impediment to
  25706. debugging---especially in the GNU system, which should make it easier
  25707. for users to exert their computing freedom (@pxref{GNU Distribution}).
  25708. Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
  25709. mechanism that allows users to get the best of both worlds: debugging
  25710. information can be stripped from the binaries and stored in separate
  25711. files. GDB is then able to load debugging information from those files,
  25712. when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
  25713. with GDB}).
  25714. The GNU distribution takes advantage of this by storing debugging
  25715. information in the @code{lib/debug} sub-directory of a separate package
  25716. output unimaginatively called @code{debug} (@pxref{Packages with
  25717. Multiple Outputs}). Users can choose to install the @code{debug} output
  25718. of a package when they need it. For instance, the following command
  25719. installs the debugging information for the GNU C Library and for GNU
  25720. Guile:
  25721. @example
  25722. guix install glibc:debug guile:debug
  25723. @end example
  25724. GDB must then be told to look for debug files in the user's profile, by
  25725. setting the @code{debug-file-directory} variable (consider setting it
  25726. from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
  25727. GDB}):
  25728. @example
  25729. (gdb) set debug-file-directory ~/.guix-profile/lib/debug
  25730. @end example
  25731. From there on, GDB will pick up debugging information from the
  25732. @file{.debug} files under @file{~/.guix-profile/lib/debug}.
  25733. In addition, you will most likely want GDB to be able to show the source
  25734. code being debugged. To do that, you will have to unpack the source
  25735. code of the package of interest (obtained with @code{guix build
  25736. --source}, @pxref{Invoking guix build}), and to point GDB to that source
  25737. directory using the @code{directory} command (@pxref{Source Path,
  25738. @code{directory},, gdb, Debugging with GDB}).
  25739. @c XXX: keep me up-to-date
  25740. The @code{debug} output mechanism in Guix is implemented by the
  25741. @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
  25742. opt-in---debugging information is available only for the packages with
  25743. definitions explicitly declaring a @code{debug} output. To check
  25744. whether a package has a @code{debug} output, use @command{guix package
  25745. --list-available} (@pxref{Invoking guix package}).
  25746. Read on for how to deal with packages lacking a @code{debug} output.
  25747. @node Rebuilding Debug Info
  25748. @section Rebuilding Debug Info
  25749. @cindex debugging info, rebuilding
  25750. As we saw above, some packages, but not all, provide debugging info in a
  25751. @code{debug} output. What can you do when debugging info is missing?
  25752. The @option{--with-debug-info} option provides a solution to that: it
  25753. allows you to rebuild the package(s) for which debugging info is
  25754. missing---and only those---and to graft those onto the application
  25755. you're debugging. Thus, while it's not as fast as installing a
  25756. @code{debug} output, it is relatively inexpensive.
  25757. Let's illustrate that. Suppose you're experiencing a bug in Inkscape
  25758. and would like to see what's going on in GLib, a library that's deep
  25759. down in its dependency graph. As it turns out, GLib does not have a
  25760. @code{debug} output and the backtrace GDB shows is all sadness:
  25761. @example
  25762. (gdb) bt
  25763. #0 0x00007ffff5f92190 in g_getenv ()
  25764. from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
  25765. #1 0x00007ffff608a7d6 in gobject_init_ctor ()
  25766. from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
  25767. #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
  25768. env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
  25769. #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
  25770. at dl-init.c:118
  25771. @end example
  25772. To address that, you install Inkscape linked against a variant GLib that
  25773. contains debug info:
  25774. @example
  25775. guix install inkscape --with-debug-info=glib
  25776. @end example
  25777. This time, debugging will be a whole lot nicer:
  25778. @example
  25779. $ gdb --args sh -c 'exec inkscape'
  25780. @dots{}
  25781. (gdb) b g_getenv
  25782. Function "g_getenv" not defined.
  25783. Make breakpoint pending on future shared library load? (y or [n]) y
  25784. Breakpoint 1 (g_getenv) pending.
  25785. (gdb) r
  25786. Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
  25787. @dots{}
  25788. (gdb) bt
  25789. #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
  25790. #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
  25791. #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
  25792. #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
  25793. env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
  25794. @dots{}
  25795. @end example
  25796. Much better!
  25797. Note that there can be packages for which @option{--with-debug-info}
  25798. will not have the desired effect. @xref{Package Transformation Options,
  25799. @option{--with-debug-info}}, for more information.
  25800. @node Security Updates
  25801. @chapter Security Updates
  25802. @cindex security updates
  25803. @cindex security vulnerabilities
  25804. Occasionally, important security vulnerabilities are discovered in software
  25805. packages and must be patched. Guix developers try hard to keep track of
  25806. known vulnerabilities and to apply fixes as soon as possible in the
  25807. @code{master} branch of Guix (we do not yet provide a ``stable'' branch
  25808. containing only security updates). The @command{guix lint} tool helps
  25809. developers find out about vulnerable versions of software packages in the
  25810. distribution:
  25811. @smallexample
  25812. $ guix lint -c cve
  25813. gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
  25814. gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
  25815. gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
  25816. @dots{}
  25817. @end smallexample
  25818. @xref{Invoking guix lint}, for more information.
  25819. Guix follows a functional
  25820. package management discipline (@pxref{Introduction}), which implies
  25821. that, when a package is changed, @emph{every package that depends on it}
  25822. must be rebuilt. This can significantly slow down the deployment of
  25823. fixes in core packages such as libc or Bash, since basically the whole
  25824. distribution would need to be rebuilt. Using pre-built binaries helps
  25825. (@pxref{Substitutes}), but deployment may still take more time than
  25826. desired.
  25827. @cindex grafts
  25828. To address this, Guix implements @dfn{grafts}, a mechanism that allows
  25829. for fast deployment of critical updates without the costs associated
  25830. with a whole-distribution rebuild. The idea is to rebuild only the
  25831. package that needs to be patched, and then to ``graft'' it onto packages
  25832. explicitly installed by the user and that were previously referring to
  25833. the original package. The cost of grafting is typically very low, and
  25834. order of magnitudes lower than a full rebuild of the dependency chain.
  25835. @cindex replacements of packages, for grafts
  25836. For instance, suppose a security update needs to be applied to Bash.
  25837. Guix developers will provide a package definition for the ``fixed''
  25838. Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
  25839. Packages}). Then, the original package definition is augmented with a
  25840. @code{replacement} field pointing to the package containing the bug fix:
  25841. @lisp
  25842. (define bash
  25843. (package
  25844. (name "bash")
  25845. ;; @dots{}
  25846. (replacement bash-fixed)))
  25847. @end lisp
  25848. From there on, any package depending directly or indirectly on Bash---as
  25849. reported by @command{guix gc --requisites} (@pxref{Invoking guix
  25850. gc})---that is installed is automatically ``rewritten'' to refer to
  25851. @code{bash-fixed} instead of @code{bash}. This grafting process takes
  25852. time proportional to the size of the package, usually less than a
  25853. minute for an ``average'' package on a recent machine. Grafting is
  25854. recursive: when an indirect dependency requires grafting, then grafting
  25855. ``propagates'' up to the package that the user is installing.
  25856. Currently, the length of the name and version of the graft and that of
  25857. the package it replaces (@code{bash-fixed} and @code{bash} in the example
  25858. above) must be equal. This restriction mostly comes from the fact that
  25859. grafting works by patching files, including binary files, directly.
  25860. Other restrictions may apply: for instance, when adding a graft to a
  25861. package providing a shared library, the original shared library and its
  25862. replacement must have the same @code{SONAME} and be binary-compatible.
  25863. The @option{--no-grafts} command-line option allows you to forcefully
  25864. avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
  25865. Thus, the command:
  25866. @example
  25867. guix build bash --no-grafts
  25868. @end example
  25869. @noindent
  25870. returns the store file name of the original Bash, whereas:
  25871. @example
  25872. guix build bash
  25873. @end example
  25874. @noindent
  25875. returns the store file name of the ``fixed'', replacement Bash. This
  25876. allows you to distinguish between the two variants of Bash.
  25877. To verify which Bash your whole profile refers to, you can run
  25878. (@pxref{Invoking guix gc}):
  25879. @example
  25880. guix gc -R `readlink -f ~/.guix-profile` | grep bash
  25881. @end example
  25882. @noindent
  25883. @dots{} and compare the store file names that you get with those above.
  25884. Likewise for a complete Guix system generation:
  25885. @example
  25886. guix gc -R `guix system build my-config.scm` | grep bash
  25887. @end example
  25888. Lastly, to check which Bash running processes are using, you can use the
  25889. @command{lsof} command:
  25890. @example
  25891. lsof | grep /gnu/store/.*bash
  25892. @end example
  25893. @node Bootstrapping
  25894. @chapter Bootstrapping
  25895. @c Adapted from the ELS 2013 paper.
  25896. @cindex bootstrapping
  25897. Bootstrapping in our context refers to how the distribution gets built
  25898. ``from nothing''. Remember that the build environment of a derivation
  25899. contains nothing but its declared inputs (@pxref{Introduction}). So
  25900. there's an obvious chicken-and-egg problem: how does the first package
  25901. get built? How does the first compiler get compiled?
  25902. It is tempting to think of this question as one that only die-hard
  25903. hackers may care about. However, while the answer to that question is
  25904. technical in nature, its implications are wide-ranging. How the
  25905. distribution is bootstrapped defines the extent to which we, as
  25906. individuals and as a collective of users and hackers, can trust the
  25907. software we run. It is a central concern from the standpoint of
  25908. @emph{security} and from a @emph{user freedom} viewpoint.
  25909. @cindex bootstrap binaries
  25910. The GNU system is primarily made of C code, with libc at its core. The
  25911. GNU build system itself assumes the availability of a Bourne shell and
  25912. command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
  25913. `grep'. Furthermore, build programs---programs that run
  25914. @code{./configure}, @code{make}, etc.---are written in Guile Scheme
  25915. (@pxref{Derivations}). Consequently, to be able to build anything at
  25916. all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
  25917. Binutils, libc, and the other packages mentioned above---the
  25918. @dfn{bootstrap binaries}.
  25919. These bootstrap binaries are ``taken for granted'', though we can also
  25920. re-create them if needed (@pxref{Preparing to Use the Bootstrap
  25921. Binaries}).
  25922. @menu
  25923. * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
  25924. * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
  25925. @end menu
  25926. @node Reduced Binary Seed Bootstrap
  25927. @section The Reduced Binary Seed Bootstrap
  25928. Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
  25929. a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
  25930. Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
  25931. GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
  25932. ``taken for granted.''
  25933. Taking the bootstrap binaries for granted means that we consider them to
  25934. be a correct and trustworthy ``seed'' for building the complete system.
  25935. Therein lies a problem: the combined size of these bootstrap binaries is
  25936. about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
  25937. or even inspecting these is next to impossible.
  25938. For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
  25939. ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
  25940. Source Bootstrap'' and while we are working towards that goal it would
  25941. be hyperbole to use that term for what we do now.}.
  25942. The Reduced Binary Seed bootstrap removes the most critical tools---from a
  25943. trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
  25944. Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
  25945. linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
  25946. written in Scheme and the Mes C Library, built for TinyCC and for GCC).
  25947. Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
  25948. C Library are built from source. From here on the more traditional
  25949. bootstrap process resumes. This approach has reduced the bootstrap
  25950. binaries in size to about 145MB in Guix v1.1.
  25951. The next step that Guix has taken is to replace the shell and all its
  25952. utilities with implementations in Guile Scheme, the @emph{Scheme-only
  25953. bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
  25954. POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
  25955. which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
  25956. Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
  25957. removed are now built from source.
  25958. Building the GNU System from source is currently only possibly by adding
  25959. some historical GNU packages as intermediate steps@footnote{Packages
  25960. such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
  25961. @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
  25962. @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
  25963. and GNU packages become more bootstrappable again (e.g., new releases of
  25964. GNU Sed will also ship as gzipped tarballs again, as alternative to the
  25965. hard to bootstrap @code{xz}-compression), this set of added packages can
  25966. hopefully be reduced again.
  25967. The graph below shows the resulting dependency graph for
  25968. @code{gcc-core-mesboot0}, the bootstrap compiler used for the
  25969. traditional bootstrap of the rest of the Guix System.
  25970. @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
  25971. @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
  25972. The only significant binary bootstrap seeds that remain@footnote{
  25973. Ignoring the 68KB @code{mescc-tools}; that will be removed later,
  25974. together with @code{mes}.} are a Scheme intepreter and a Scheme
  25975. compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
  25976. static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
  25977. to get Guile running.}.
  25978. This further reduction has brought down the size of the binary seed to
  25979. about 60MB for @code{i686-linux} and @code{x86_64-linux}.
  25980. Work is ongoing to remove all binary blobs from our free software
  25981. bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
  25982. is work to bring these bootstraps to the @code{arm-linux} and
  25983. @code{aarch64-linux} architectures and to the Hurd.
  25984. If you are interested, join us on @samp{#bootstrappable} on the Freenode
  25985. IRC network or discuss on @email{bug-mes@@gnu.org} or
  25986. @email{gash-devel@@nongnu.org}.
  25987. @node Preparing to Use the Bootstrap Binaries
  25988. @section Preparing to Use the Bootstrap Binaries
  25989. @c As of Emacs 24.3, Info-mode displays the image, but since it's a
  25990. @c large image, it's hard to scroll. Oh well.
  25991. @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
  25992. The figure above shows the very beginning of the dependency graph of the
  25993. distribution, corresponding to the package definitions of the @code{(gnu
  25994. packages bootstrap)} module. A similar figure can be generated with
  25995. @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
  25996. @example
  25997. guix graph -t derivation \
  25998. -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
  25999. | dot -Tps > gcc.ps
  26000. @end example
  26001. or, for the further Reduced Binary Seed bootstrap
  26002. @example
  26003. guix graph -t derivation \
  26004. -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
  26005. | dot -Tps > mes.ps
  26006. @end example
  26007. At this level of detail, things are
  26008. slightly complex. First, Guile itself consists of an ELF executable,
  26009. along with many source and compiled Scheme files that are dynamically
  26010. loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
  26011. tarball shown in this graph. This tarball is part of Guix's ``source''
  26012. distribution, and gets inserted into the store with @code{add-to-store}
  26013. (@pxref{The Store}).
  26014. But how do we write a derivation that unpacks this tarball and adds it
  26015. to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
  26016. derivation---the first one that gets built---uses @code{bash} as its
  26017. builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
  26018. @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
  26019. @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
  26020. the Guix source distribution, whose sole purpose is to allow the Guile
  26021. tarball to be unpacked.
  26022. Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
  26023. Guile that can be used to run subsequent build programs. Its first task
  26024. is to download tarballs containing the other pre-built binaries---this
  26025. is what the @file{.tar.xz.drv} derivations do. Guix modules such as
  26026. @code{ftp-client.scm} are used for this purpose. The
  26027. @code{module-import.drv} derivations import those modules in a directory
  26028. in the store, using the original layout. The
  26029. @code{module-import-compiled.drv} derivations compile those modules, and
  26030. write them in an output directory with the right layout. This
  26031. corresponds to the @code{#:modules} argument of
  26032. @code{build-expression->derivation} (@pxref{Derivations}).
  26033. Finally, the various tarballs are unpacked by the derivations
  26034. @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
  26035. @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
  26036. point we have a working C tool chain.
  26037. @unnumberedsec Building the Build Tools
  26038. Bootstrapping is complete when we have a full tool chain that does not
  26039. depend on the pre-built bootstrap tools discussed above. This
  26040. no-dependency requirement is verified by checking whether the files of
  26041. the final tool chain contain references to the @file{/gnu/store}
  26042. directories of the bootstrap inputs. The process that leads to this
  26043. ``final'' tool chain is described by the package definitions found in
  26044. the @code{(gnu packages commencement)} module.
  26045. The @command{guix graph} command allows us to ``zoom out'' compared to
  26046. the graph above, by looking at the level of package objects instead of
  26047. individual derivations---remember that a package may translate to
  26048. several derivations, typically one derivation to download its source,
  26049. one to build the Guile modules it needs, and one to actually build the
  26050. package from source. The command:
  26051. @example
  26052. guix graph -t bag \
  26053. -e '(@@@@ (gnu packages commencement)
  26054. glibc-final-with-bootstrap-bash)' | xdot -
  26055. @end example
  26056. @noindent
  26057. displays the dependency graph leading to the ``final'' C
  26058. library@footnote{You may notice the @code{glibc-intermediate} label,
  26059. suggesting that it is not @emph{quite} final, but as a good
  26060. approximation, we will consider it final.}, depicted below.
  26061. @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
  26062. @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
  26063. The first tool that gets built with the bootstrap binaries is
  26064. GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
  26065. for all the following packages. From there Findutils and Diffutils get
  26066. built.
  26067. Then come the first-stage Binutils and GCC, built as pseudo cross
  26068. tools---i.e., with @option{--target} equal to @option{--host}. They are
  26069. used to build libc. Thanks to this cross-build trick, this libc is
  26070. guaranteed not to hold any reference to the initial tool chain.
  26071. From there the final Binutils and GCC (not shown above) are built. GCC
  26072. uses @command{ld} from the final Binutils, and links programs against
  26073. the just-built libc. This tool chain is used to build the other
  26074. packages used by Guix and by the GNU Build System: Guile, Bash,
  26075. Coreutils, etc.
  26076. And voilà! At this point we have the complete set of build tools that
  26077. the GNU Build System expects. These are in the @code{%final-inputs}
  26078. variable of the @code{(gnu packages commencement)} module, and are
  26079. implicitly used by any package that uses @code{gnu-build-system}
  26080. (@pxref{Build Systems, @code{gnu-build-system}}).
  26081. @unnumberedsec Building the Bootstrap Binaries
  26082. @cindex bootstrap binaries
  26083. Because the final tool chain does not depend on the bootstrap binaries,
  26084. those rarely need to be updated. Nevertheless, it is useful to have an
  26085. automated way to produce them, should an update occur, and this is what
  26086. the @code{(gnu packages make-bootstrap)} module provides.
  26087. The following command builds the tarballs containing the bootstrap binaries
  26088. (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
  26089. bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
  26090. and Guile, and a tarball containing a mixture of Coreutils and other basic
  26091. command-line tools):
  26092. @example
  26093. guix build bootstrap-tarballs
  26094. @end example
  26095. The generated tarballs are those that should be referred to in the
  26096. @code{(gnu packages bootstrap)} module mentioned at the beginning of
  26097. this section.
  26098. Still here? Then perhaps by now you've started to wonder: when do we
  26099. reach a fixed point? That is an interesting question! The answer is
  26100. unknown, but if you would like to investigate further (and have
  26101. significant computational and storage resources to do so), then let us
  26102. know.
  26103. @unnumberedsec Reducing the Set of Bootstrap Binaries
  26104. Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
  26105. binary code! Why is that a problem? It's a problem because these big chunks
  26106. of binary code are practically non-auditable, which makes it hard to establish
  26107. what source code produced them. Every unauditable binary also leaves us
  26108. vulnerable to compiler backdoors as described by Ken Thompson in the 1984
  26109. paper @emph{Reflections on Trusting Trust}.
  26110. This is mitigated by the fact that our bootstrap binaries were generated
  26111. from an earlier Guix revision. Nevertheless it lacks the level of
  26112. transparency that we get in the rest of the package dependency graph,
  26113. where Guix always gives us a source-to-binary mapping. Thus, our goal
  26114. is to reduce the set of bootstrap binaries to the bare minimum.
  26115. The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
  26116. on-going projects to do that. One of these is about replacing the
  26117. bootstrap GCC with a sequence of assemblers, interpreters, and compilers
  26118. of increasing complexity, which could be built from source starting from
  26119. a simple and auditable assembler.
  26120. Our first major achievement is the replacement of of GCC, the GNU C Library
  26121. and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
  26122. (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
  26123. and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
  26124. bootstrapped yet and thus we inject them as binary seeds. We call this the
  26125. Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
  26126. binaries! Also, it has eliminated the C compiler binary; i686-linux and
  26127. x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
  26128. Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
  26129. also looking at any other bootstrap binaries. Your help is welcome!
  26130. @node Porting
  26131. @chapter Porting to a New Platform
  26132. As discussed above, the GNU distribution is self-contained, and
  26133. self-containment is achieved by relying on pre-built ``bootstrap
  26134. binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
  26135. operating system kernel, CPU architecture, and application binary
  26136. interface (ABI). Thus, to port the distribution to a platform that is
  26137. not yet supported, one must build those bootstrap binaries, and update
  26138. the @code{(gnu packages bootstrap)} module to use them on that platform.
  26139. Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
  26140. When everything goes well, and assuming the GNU tool chain supports the
  26141. target platform, this can be as simple as running a command like this
  26142. one:
  26143. @example
  26144. guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
  26145. @end example
  26146. For this to work, the @code{glibc-dynamic-linker} procedure in
  26147. @code{(gnu packages bootstrap)} must be augmented to return the right
  26148. file name for libc's dynamic linker on that platform; likewise,
  26149. @code{system->linux-architecture} in @code{(gnu packages linux)} must be
  26150. taught about the new platform.
  26151. Once these are built, the @code{(gnu packages bootstrap)} module needs
  26152. to be updated to refer to these binaries on the target platform. That
  26153. is, the hashes and URLs of the bootstrap tarballs for the new platform
  26154. must be added alongside those of the currently supported platforms. The
  26155. bootstrap Guile tarball is treated specially: it is expected to be
  26156. available locally, and @file{gnu/local.mk} has rules to download it for
  26157. the supported architectures; a rule for the new platform must be added
  26158. as well.
  26159. In practice, there may be some complications. First, it may be that the
  26160. extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
  26161. above) is not recognized by all the GNU tools. Typically, glibc
  26162. recognizes some of these, whereas GCC uses an extra @option{--with-abi}
  26163. configure flag (see @code{gcc.scm} for examples of how to handle this).
  26164. Second, some of the required packages could fail to build for that
  26165. platform. Lastly, the generated binaries could be broken for some
  26166. reason.
  26167. @c *********************************************************************
  26168. @include contributing.texi
  26169. @c *********************************************************************
  26170. @node Acknowledgments
  26171. @chapter Acknowledgments
  26172. Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
  26173. which was designed and
  26174. implemented by Eelco Dolstra, with contributions from other people (see
  26175. the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
  26176. management, and promoted unprecedented features, such as transactional
  26177. package upgrades and rollbacks, per-user profiles, and referentially
  26178. transparent build processes. Without this work, Guix would not exist.
  26179. The Nix-based software distributions, Nixpkgs and NixOS, have also been
  26180. an inspiration for Guix.
  26181. GNU@tie{}Guix itself is a collective work with contributions from a
  26182. number of people. See the @file{AUTHORS} file in Guix for more
  26183. information on these fine people. The @file{THANKS} file lists people
  26184. who have helped by reporting bugs, taking care of the infrastructure,
  26185. providing artwork and themes, making suggestions, and more---thank you!
  26186. @c *********************************************************************
  26187. @node GNU Free Documentation License
  26188. @appendix GNU Free Documentation License
  26189. @cindex license, GNU Free Documentation License
  26190. @include fdl-1.3.texi
  26191. @c *********************************************************************
  26192. @node Concept Index
  26193. @unnumbered Concept Index
  26194. @printindex cp
  26195. @node Programming Index
  26196. @unnumbered Programming Index
  26197. @syncodeindex tp fn
  26198. @syncodeindex vr fn
  26199. @printindex fn
  26200. @bye
  26201. @c Local Variables:
  26202. @c ispell-local-dictionary: "american";
  26203. @c End: