6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
14 @set KEY-SERVER pool.sks-keyservers.net
16 @c Base URL for downloads.
17 @set BASE-URL https://ftp.gnu.org/gnu/guix
19 @c The official substitute server used by default.
20 @set SUBSTITUTE-SERVER ci.guix.gnu.org
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 ng0@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018 Marius Bakke@*
50 Copyright @copyright{} 2017 Hartmut Goebel@*
51 Copyright @copyright{} 2017 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018, 2019 Gábor Boskovits@*
62 Copyright @copyright{} 2018, 2019 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019 Diego Nicola Barbato@*
67 Copyright @copyright{} 2019 Ivan Petkov@*
69 Permission is granted to copy, distribute and/or modify this document
70 under the terms of the GNU Free Documentation License, Version 1.3 or
71 any later version published by the Free Software Foundation; with no
72 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
73 copy of the license is included in the section entitled ``GNU Free
74 Documentation License''.
77 @dircategory System administration
79 * Guix: (guix). Manage installed software and system configuration.
80 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
81 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
82 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
83 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
86 @dircategory Software development
88 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
89 * guix build: (guix)Invoking guix build. Building packages.
90 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
94 @title GNU Guix Reference Manual
95 @subtitle Using the GNU Guix Functional Package Manager
96 @author The GNU Guix Developers
99 @vskip 0pt plus 1filll
100 Edition @value{EDITION} @*
108 @c *********************************************************************
112 This document describes GNU Guix version @value{VERSION}, a functional
113 package management tool written for the GNU system.
115 @c TRANSLATORS: You can replace the following paragraph with information on
116 @c how to join your own translation team and how to report issues with the
118 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
119 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
120 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
121 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
122 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
123 would like to translate it in your native language, consider joining the
124 @uref{https://translationproject.org/domain/guix-manual.html, Translation
128 * Introduction:: What is Guix about?
129 * Installation:: Installing Guix.
130 * System Installation:: Installing the whole operating system.
131 * Package Management:: Package installation, upgrade, etc.
132 * Development:: Guix-aided software development.
133 * Programming Interface:: Using Guix in Scheme.
134 * Utilities:: Package management commands.
135 * System Configuration:: Configuring the operating system.
136 * Documentation:: Browsing software user manuals.
137 * Installing Debugging Files:: Feeding the debugger.
138 * Security Updates:: Deploying security fixes quickly.
139 * Bootstrapping:: GNU/Linux built from scratch.
140 * Porting:: Targeting another platform or kernel.
141 * Contributing:: Your help needed!
143 * Acknowledgments:: Thanks!
144 * GNU Free Documentation License:: The license of this manual.
145 * Concept Index:: Concepts.
146 * Programming Index:: Data types, functions, and variables.
149 --- The Detailed Node Listing ---
153 * Managing Software the Guix Way:: What's special.
154 * GNU Distribution:: The packages and tools.
158 * Binary Installation:: Getting Guix running in no time!
159 * Requirements:: Software needed to build and run Guix.
160 * Running the Test Suite:: Testing Guix.
161 * Setting Up the Daemon:: Preparing the build daemon's environment.
162 * Invoking guix-daemon:: Running the build daemon.
163 * Application Setup:: Application-specific setup.
165 Setting Up the Daemon
167 * Build Environment Setup:: Preparing the isolated build environment.
168 * Daemon Offload Setup:: Offloading builds to remote machines.
169 * SELinux Support:: Using an SELinux policy for the daemon.
173 * Limitations:: What you can expect.
174 * Hardware Considerations:: Supported hardware.
175 * USB Stick and DVD Installation:: Preparing the installation medium.
176 * Preparing for Installation:: Networking, partitioning, etc.
177 * Guided Graphical Installation:: Easy graphical installation.
178 * Manual Installation:: Manual installation for wizards.
179 * After System Installation:: When installation succeeded.
180 * Installing Guix in a VM:: Guix System playground.
181 * Building the Installation Image:: How this comes to be.
185 * Keyboard Layout and Networking and Partitioning:: Initial setup.
186 * Proceeding with the Installation:: Installing.
190 * Features:: How Guix will make your life brighter.
191 * Invoking guix package:: Package installation, removal, etc.
192 * Substitutes:: Downloading pre-built binaries.
193 * Packages with Multiple Outputs:: Single source package, multiple outputs.
194 * Invoking guix gc:: Running the garbage collector.
195 * Invoking guix pull:: Fetching the latest Guix and distribution.
196 * Channels:: Customizing the package collection.
197 * Inferiors:: Interacting with another revision of Guix.
198 * Invoking guix describe:: Display information about your Guix revision.
199 * Invoking guix archive:: Exporting and importing store files.
203 * Official Substitute Server:: One particular source of substitutes.
204 * Substitute Server Authorization:: How to enable or disable substitutes.
205 * Substitute Authentication:: How Guix verifies substitutes.
206 * Proxy Settings:: How to get substitutes via proxy.
207 * Substitution Failure:: What happens when substitution fails.
208 * On Trusting Binaries:: How can you trust that binary blob?
212 * Invoking guix environment:: Setting up development environments.
213 * Invoking guix pack:: Creating software bundles.
215 Programming Interface
217 * Package Modules:: Packages from the programmer's viewpoint.
218 * Defining Packages:: Defining new packages.
219 * Build Systems:: Specifying how packages are built.
220 * The Store:: Manipulating the package store.
221 * Derivations:: Low-level interface to package derivations.
222 * The Store Monad:: Purely functional interface to the store.
223 * G-Expressions:: Manipulating build expressions.
224 * Invoking guix repl:: Fiddling with Guix interactively.
228 * package Reference:: The package data type.
229 * origin Reference:: The origin data type.
233 * Invoking guix build:: Building packages from the command line.
234 * Invoking guix edit:: Editing package definitions.
235 * Invoking guix download:: Downloading a file and printing its hash.
236 * Invoking guix hash:: Computing the cryptographic hash of a file.
237 * Invoking guix import:: Importing package definitions.
238 * Invoking guix refresh:: Updating package definitions.
239 * Invoking guix lint:: Finding errors in package definitions.
240 * Invoking guix size:: Profiling disk usage.
241 * Invoking guix graph:: Visualizing the graph of packages.
242 * Invoking guix publish:: Sharing substitutes.
243 * Invoking guix challenge:: Challenging substitute servers.
244 * Invoking guix copy:: Copying to and from a remote store.
245 * Invoking guix container:: Process isolation.
246 * Invoking guix weather:: Assessing substitute availability.
247 * Invoking guix processes:: Listing client processes.
249 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.
258 * Using the Configuration System:: Customizing your GNU system.
259 * operating-system Reference:: Detail of operating-system declarations.
260 * File Systems:: Configuring file system mounts.
261 * Mapped Devices:: Block device extra processing.
262 * User Accounts:: Specifying user accounts.
263 * Keyboard Layout:: How the system interprets key strokes.
264 * Locales:: Language and cultural convention settings.
265 * Services:: Specifying system services.
266 * Setuid Programs:: Programs running with root privileges.
267 * X.509 Certificates:: Authenticating HTTPS servers.
268 * Name Service Switch:: Configuring libc's name service switch.
269 * Initial RAM Disk:: Linux-Libre bootstrapping.
270 * Bootloader Configuration:: Configuring the boot loader.
271 * Invoking guix system:: Instantiating a system configuration.
272 * Running Guix in a VM:: How to run Guix System in a virtual machine.
273 * Defining Services:: Adding new service definitions.
277 * Base Services:: Essential system services.
278 * Scheduled Job Execution:: The mcron service.
279 * Log Rotation:: The rottlog service.
280 * Networking Services:: Network setup, SSH daemon, etc.
281 * X Window:: Graphical display.
282 * Printing Services:: Local and remote printer support.
283 * Desktop Services:: D-Bus and desktop services.
284 * Sound Services:: ALSA and Pulseaudio services.
285 * Database Services:: SQL databases, key-value stores, etc.
286 * Mail Services:: IMAP, POP3, SMTP, and all that.
287 * Messaging Services:: Messaging services.
288 * Telephony Services:: Telephony services.
289 * Monitoring Services:: Monitoring services.
290 * Kerberos Services:: Kerberos services.
291 * Web Services:: Web servers.
292 * Certificate Services:: TLS certificates via Let's Encrypt.
293 * DNS Services:: DNS daemons.
294 * VPN Services:: VPN daemons.
295 * Network File System:: NFS related services.
296 * Continuous Integration:: The Cuirass service.
297 * Power Management Services:: Extending battery life.
298 * Audio Services:: The MPD.
299 * Virtualization Services:: Virtualization services.
300 * Version Control Services:: Providing remote access to Git repositories.
301 * Game Services:: Game servers.
302 * Miscellaneous Services:: Other services.
306 * Service Composition:: The model for composing services.
307 * Service Types and Services:: Types and services.
308 * Service Reference:: API reference.
309 * Shepherd Services:: A particular type of service.
314 @c *********************************************************************
316 @chapter Introduction
319 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
320 using the international phonetic alphabet (IPA).} is a package
321 management tool for and distribution of the GNU system.
322 Guix makes it easy for unprivileged
323 users to install, upgrade, or remove software packages, to roll back to a
324 previous package set, to build packages from source, and generally
325 assists with the creation and maintenance of software environments.
328 @cindex GuixSD, now Guix System
329 @cindex Guix System Distribution, now Guix System
330 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
331 complements the available tools without interference (@pxref{Installation}),
332 or you can use it as a standalone operating system distribution,
333 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
334 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
335 group everything under the ``Guix'' banner since, after all, Guix System is
336 readily available through the @command{guix system} command, even if you're
337 using a different distro underneath!}. @xref{GNU Distribution}.
340 * Managing Software the Guix Way:: What's special.
341 * GNU Distribution:: The packages and tools.
344 @node Managing Software the Guix Way
345 @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}).
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}).
358 @cindex extensibility of the distribution
359 @cindex customization, of packages
360 Guix includes package definitions for many GNU and non-GNU packages, all
361 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
362 user's computing freedom}. It is @emph{extensible}: users can write
363 their own package definitions (@pxref{Defining Packages}) and make them
364 available as independent package modules (@pxref{Package Modules}). It
365 is also @emph{customizable}: users can @emph{derive} specialized package
366 definitions from existing ones, including from the command line
367 (@pxref{Package Transformation Options}).
369 @cindex functional package management
371 Under the hood, Guix implements the @dfn{functional package management}
372 discipline pioneered by Nix (@pxref{Acknowledgments}).
373 In Guix, the package build and installation process is seen
374 as a @emph{function}, in the mathematical sense. That function takes inputs,
375 such as build scripts, a compiler, and libraries, and
376 returns an installed package. As a pure function, its result depends
377 solely on its inputs---for instance, it cannot refer to software or
378 scripts that were not explicitly passed as inputs. A build function
379 always produces the same result when passed a given set of inputs. It
380 cannot alter the environment of the running system in
381 any way; for instance, it cannot create, modify, or delete files outside
382 of its build and installation directories. This is achieved by running
383 build processes in isolated environments (or @dfn{containers}), where only their
384 explicit inputs are visible.
387 The result of package build functions is @dfn{cached} in the file
388 system, in a special directory called @dfn{the store} (@pxref{The
389 Store}). Each package is installed in a directory of its own in the
390 store---by default under @file{/gnu/store}. The directory name contains
391 a hash of all the inputs used to build that package; thus, changing an
392 input yields a different directory name.
394 This approach is the foundation for the salient features of Guix: support
395 for transactional package upgrade and rollback, per-user installation, and
396 garbage collection of packages (@pxref{Features}).
399 @node GNU Distribution
400 @section GNU Distribution
403 Guix comes with a distribution of the GNU system consisting entirely of
404 free software@footnote{The term ``free'' here refers to the
405 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
406 users of that software}.}. The
407 distribution can be installed on its own (@pxref{System Installation}),
408 but it is also possible to install Guix as a package manager on top of
409 an installed GNU/Linux system (@pxref{Installation}). When we need to
410 distinguish between the two, we refer to the standalone distribution as
413 The distribution provides core GNU packages such as GNU libc, GCC, and
414 Binutils, as well as many GNU and non-GNU applications. The complete
415 list of available packages can be browsed
416 @url{https://www.gnu.org/software/guix/packages,on-line} or by
417 running @command{guix package} (@pxref{Invoking guix package}):
420 guix package --list-available
423 Our goal is to provide a practical 100% free software distribution of
424 Linux-based and other variants of GNU, with a focus on the promotion and
425 tight integration of GNU components, and an emphasis on programs and
426 tools that help users exert that freedom.
428 Packages are currently available on the following platforms:
433 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
436 Intel 32-bit architecture (IA32), Linux-Libre kernel;
439 ARMv7-A architecture with hard float, Thumb-2 and NEON,
440 using the EABI hard-float application binary interface (ABI),
441 and Linux-Libre kernel.
444 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
447 little-endian 64-bit MIPS processors, specifically the Loongson series,
448 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
449 supported; in particular, the project's build farms no longer provide
450 substitutes for this architecture.
454 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
455 configuration and Guix takes care of instantiating the configuration in a
456 transactional, reproducible, and stateless fashion (@pxref{System
457 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
458 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
459 Manual}), the well-known GNU utilities and tool chain, as well as the
460 graphical environment or system services of your choice.
462 Guix System is available on all the above platforms except
463 @code{mips64el-linux}.
466 For information on porting to other architectures or kernels,
469 Building this distribution is a cooperative effort, and you are invited
470 to join! @xref{Contributing}, for information about how you can help.
473 @c *********************************************************************
475 @chapter Installation
477 @cindex installing Guix
480 We recommend the use of this
481 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
482 shell installer script} to install Guix on top of a running GNU/Linux system,
483 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
484 with the installation of the package manager, which can be done on top of a
485 running GNU/Linux system. If, instead, you want to install the complete GNU
486 operating system, @pxref{System Installation}.} The script automates the
487 download, installation, and initial configuration of Guix. It should be run
491 @cindex foreign distro
492 @cindex directories related to foreign distro
493 When installed on a foreign distro, GNU@tie{}Guix complements the available
494 tools without interference. Its data lives exclusively in two directories,
495 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
496 such as @file{/etc}, are left untouched.
498 Once installed, Guix can be updated by running @command{guix pull}
499 (@pxref{Invoking guix pull}).
501 If you prefer to perform the installation steps manually or want to tweak
502 them, you may find the following subsections useful. They describe the
503 software requirements of Guix, as well as how to install it manually and get
507 * Binary Installation:: Getting Guix running in no time!
508 * Requirements:: Software needed to build and run Guix.
509 * Running the Test Suite:: Testing Guix.
510 * Setting Up the Daemon:: Preparing the build daemon's environment.
511 * Invoking guix-daemon:: Running the build daemon.
512 * Application Setup:: Application-specific setup.
515 @node Binary Installation
516 @section Binary Installation
518 @cindex installing Guix from binaries
519 @cindex installer script
520 This section describes how to install Guix on an arbitrary system from a
521 self-contained tarball providing binaries for Guix and for all its
522 dependencies. This is often quicker than installing from source, which
523 is described in the next sections. The only requirement is to have
526 @c Note duplicated from the ``Installation'' node.
528 We recommend the use of this
529 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
530 shell installer script}. The script automates the download, installation, and
531 initial configuration steps described below. It should be run as the root
535 Installing goes along these lines:
539 @cindex downloading Guix binary
540 Download the binary tarball from
541 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
542 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
543 already running the kernel Linux, and so on.
545 @c The following is somewhat duplicated in ``System Installation''.
546 Make sure to download the associated @file{.sig} file and to verify the
547 authenticity of the tarball against it, along these lines:
550 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
551 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
554 If that command fails because you do not have the required public key,
555 then run this command to import it:
558 $ gpg --keyserver @value{KEY-SERVER} \
559 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
563 and rerun the @code{gpg --verify} command.
564 @c end authentication part
567 Now, you need to become the @code{root} user. Depending on your distribution,
568 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
572 # tar --warning=no-timestamp -xf \
573 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
574 # mv var/guix /var/ && mv gnu /
577 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
578 The latter contains a ready-to-use profile for @code{root} (see next
581 Do @emph{not} unpack the tarball on a working Guix system since that
582 would overwrite its own essential files.
584 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
585 not emit warnings about ``implausibly old time stamps'' (such
586 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
588 They stem from the fact that all the
589 files in the archive have their modification time set to zero (which
590 means January 1st, 1970.) This is done on purpose to make sure the
591 archive content is independent of its creation time, thus making it
595 Make the profile available under @file{~root/.config/guix/current}, which is
596 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
599 # mkdir -p ~root/.config/guix
600 # ln -sf /var/guix/profiles/per-user/root/current-guix \
601 ~root/.config/guix/current
604 Source @file{etc/profile} to augment @code{PATH} and other relevant
605 environment variables:
608 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
609 source $GUIX_PROFILE/etc/profile
613 Create the group and user accounts for build users as explained below
614 (@pxref{Build Environment Setup}).
617 Run the daemon, and set it to automatically start on boot.
619 If your host distro uses the systemd init system, this can be achieved
622 @c Versions of systemd that supported symlinked service files are not
623 @c yet widely deployed, so we should suggest that users copy the service
626 @c See this thread for more information:
627 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
630 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
632 # systemctl start guix-daemon && systemctl enable guix-daemon
635 If your host distro uses the Upstart init system:
638 # initctl reload-configuration
639 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
644 Otherwise, you can still start the daemon manually with:
647 # ~root/.config/guix/current/bin/guix-daemon \
648 --build-users-group=guixbuild
652 Make the @command{guix} command available to other users on the machine,
656 # mkdir -p /usr/local/bin
658 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
661 It is also a good idea to make the Info version of this manual available
665 # mkdir -p /usr/local/share/info
666 # cd /usr/local/share/info
667 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
671 That way, assuming @file{/usr/local/share/info} is in the search path,
672 running @command{info guix} will open this manual (@pxref{Other Info
673 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
677 @cindex substitutes, authorization thereof
678 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
679 (@pxref{Substitutes}), authorize them:
682 # guix archive --authorize < \
683 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
687 Each user may need to perform a few additional steps to make their Guix
688 environment ready for use, @pxref{Application Setup}.
691 Voilà, the installation is complete!
693 You can confirm that Guix is working by installing a sample package into
700 The binary installation tarball can be (re)produced and verified simply
701 by running the following command in the Guix source tree:
704 make guix-binary.@var{system}.tar.xz
708 ...@: which, in turn, runs:
711 guix pack -s @var{system} --localstatedir \
712 --profile-name=current-guix guix
715 @xref{Invoking guix pack}, for more info on this handy tool.
718 @section Requirements
720 This section lists requirements when building Guix from source. The
721 build procedure for Guix is the same as for other GNU software, and is
722 not covered here. Please see the files @file{README} and @file{INSTALL}
723 in the Guix source tree for additional details.
725 @cindex official website
726 GNU Guix is available for download from its website at
727 @url{https://www.gnu.org/software/guix/}.
729 GNU Guix depends on the following packages:
732 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
733 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
736 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
737 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
738 Guile,, gnutls-guile, GnuTLS-Guile});
740 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
743 @c FIXME: Specify a version number once a release has been made.
744 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
746 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON};
747 @item @url{https://zlib.net, zlib};
748 @item @url{https://www.gnu.org/software/make/, GNU Make}.
751 The following dependencies are optional:
755 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
756 Support for build offloading (@pxref{Daemon Offload Setup}) and
757 @command{guix copy} (@pxref{Invoking guix copy}) depends on
758 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
759 version 0.10.2 or later.
762 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
763 substitutes can be used and @command{guix publish} can compress substitutes
767 When @url{http://www.bzip.org, libbz2} is available,
768 @command{guix-daemon} can use it to compress build logs.
771 Unless @code{--disable-daemon} was passed to @command{configure}, the
772 following packages are also needed:
775 @item @url{https://gnupg.org/, GNU libgcrypt};
776 @item @url{https://sqlite.org, SQLite 3};
777 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
781 @cindex state directory
782 When configuring Guix on a system that already has a Guix installation,
783 be sure to specify the same state directory as the existing installation
784 using the @code{--localstatedir} option of the @command{configure}
785 script (@pxref{Directory Variables, @code{localstatedir},, standards,
786 GNU Coding Standards}). The @command{configure} script protects against
787 unintended misconfiguration of @var{localstatedir} so you do not
788 inadvertently corrupt your store (@pxref{The Store}).
790 @cindex Nix, compatibility
791 When a working installation of @url{https://nixos.org/nix/, the Nix package
792 manager} is available, you
793 can instead configure Guix with @code{--disable-daemon}. In that case,
794 Nix replaces the three dependencies above.
796 Guix is compatible with Nix, so it is possible to share the same store
797 between both. To do so, you must pass @command{configure} not only the
798 same @code{--with-store-dir} value, but also the same
799 @code{--localstatedir} value. The latter is essential because it
800 specifies where the database that stores metadata about the store is
801 located, among other things. The default values for Nix are
802 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
803 Note that @code{--disable-daemon} is not required if
804 your goal is to share the store with Nix.
806 @node Running the Test Suite
807 @section Running the Test Suite
810 After a successful @command{configure} and @code{make} run, it is a good
811 idea to run the test suite. It can help catch issues with the setup or
812 environment, or bugs in Guix itself---and really, reporting test
813 failures is a good way to help improve the software. To run the test
820 Test cases can run in parallel: you can use the @code{-j} option of
821 GNU@tie{}make to speed things up. The first run may take a few minutes
822 on a recent machine; subsequent runs will be faster because the store
823 that is created for test purposes will already have various things in
826 It is also possible to run a subset of the tests by defining the
827 @code{TESTS} makefile variable as in this example:
830 make check TESTS="tests/store.scm tests/cpio.scm"
833 By default, tests results are displayed at a file level. In order to
834 see the details of every individual test cases, it is possible to define
835 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
838 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
841 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
842 @file{test-suite.log} file. Please specify the Guix version being used
843 as well as version numbers of the dependencies (@pxref{Requirements}) in
846 Guix also comes with a whole-system test suite that tests complete
847 Guix System instances. It can only run on systems where
848 Guix is already installed, using:
855 or, again, by defining @code{TESTS} to select a subset of tests to run:
858 make check-system TESTS="basic mcron"
861 These system tests are defined in the @code{(gnu tests @dots{})}
862 modules. They work by running the operating systems under test with
863 lightweight instrumentation in a virtual machine (VM). They can be
864 computationally intensive or rather cheap, depending on whether
865 substitutes are available for their dependencies (@pxref{Substitutes}).
866 Some of them require a lot of storage space to hold VM images.
868 Again in case of test failures, please send @email{bug-guix@@gnu.org}
871 @node Setting Up the Daemon
872 @section Setting Up the Daemon
875 Operations such as building a package or running the garbage collector
876 are all performed by a specialized process, the @dfn{build daemon}, on
877 behalf of clients. Only the daemon may access the store and its
878 associated database. Thus, any operation that manipulates the store
879 goes through the daemon. For instance, command-line tools such as
880 @command{guix package} and @command{guix build} communicate with the
881 daemon (@i{via} remote procedure calls) to instruct it what to do.
883 The following sections explain how to prepare the build daemon's
884 environment. See also @ref{Substitutes}, for information on how to allow
885 the daemon to download pre-built binaries.
888 * Build Environment Setup:: Preparing the isolated build environment.
889 * Daemon Offload Setup:: Offloading builds to remote machines.
890 * SELinux Support:: Using an SELinux policy for the daemon.
893 @node Build Environment Setup
894 @subsection Build Environment Setup
896 @cindex build environment
897 In a standard multi-user setup, Guix and its daemon---the
898 @command{guix-daemon} program---are installed by the system
899 administrator; @file{/gnu/store} is owned by @code{root} and
900 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
901 Guix tools to build packages or otherwise access the store, and the
902 daemon will do it on their behalf, ensuring that the store is kept in a
903 consistent state, and allowing built packages to be shared among users.
906 When @command{guix-daemon} runs as @code{root}, you may not want package
907 build processes themselves to run as @code{root} too, for obvious
908 security reasons. To avoid that, a special pool of @dfn{build users}
909 should be created for use by build processes started by the daemon.
910 These build users need not have a shell and a home directory: they will
911 just be used when the daemon drops @code{root} privileges in build
912 processes. Having several such users allows the daemon to launch
913 distinct build processes under separate UIDs, which guarantees that they
914 do not interfere with each other---an essential feature since builds are
915 regarded as pure functions (@pxref{Introduction}).
917 On a GNU/Linux system, a build user pool may be created like this (using
918 Bash syntax and the @code{shadow} commands):
920 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
921 @c for why `-G' is needed.
923 # groupadd --system guixbuild
924 # for i in `seq -w 1 10`;
926 useradd -g guixbuild -G guixbuild \
927 -d /var/empty -s `which nologin` \
928 -c "Guix build user $i" --system \
934 The number of build users determines how many build jobs may run in
935 parallel, as specified by the @option{--max-jobs} option
936 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
937 @command{guix system vm} and related commands, you may need to add the
938 build users to the @code{kvm} group so they can access @file{/dev/kvm},
939 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
940 (@pxref{Invoking guix system}).
942 The @code{guix-daemon} program may then be run as @code{root} with the
943 following command@footnote{If your machine uses the systemd init system,
944 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
945 file in @file{/etc/systemd/system} will ensure that
946 @command{guix-daemon} is automatically started. Similarly, if your
947 machine uses the Upstart init system, drop the
948 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
949 file in @file{/etc/init}.}:
952 # guix-daemon --build-users-group=guixbuild
957 This way, the daemon starts build processes in a chroot, under one of
958 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
959 environment contains nothing but:
961 @c Keep this list in sync with libstore/build.cc! -----------------------
964 a minimal @code{/dev} directory, created mostly independently from the
965 host @code{/dev}@footnote{``Mostly'', because while the set of files
966 that appear in the chroot's @code{/dev} is fixed, most of these files
967 can only be created if the host has them.};
970 the @code{/proc} directory; it only shows the processes of the container
971 since a separate PID name space is used;
974 @file{/etc/passwd} with an entry for the current user and an entry for
978 @file{/etc/group} with an entry for the user's group;
981 @file{/etc/hosts} with an entry that maps @code{localhost} to
985 a writable @file{/tmp} directory.
988 You can influence the directory where the daemon stores build trees
989 @i{via} the @code{TMPDIR} environment variable. However, the build tree
990 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
991 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
992 This way, the value of @code{TMPDIR} does not leak inside build
993 environments, which avoids discrepancies in cases where build processes
994 capture the name of their build tree.
997 The daemon also honors the @code{http_proxy} environment variable for
998 HTTP downloads it performs, be it for fixed-output derivations
999 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
1001 If you are installing Guix as an unprivileged user, it is still possible
1002 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
1003 However, build processes will not be isolated from one another, and not
1004 from the rest of the system. Thus, build processes may interfere with
1005 each other, and may access programs, libraries, and other files
1006 available on the system---making it much harder to view them as
1007 @emph{pure} functions.
1010 @node Daemon Offload Setup
1011 @subsection Using the Offload Facility
1015 When desired, the build daemon can @dfn{offload} derivation builds to
1016 other machines running Guix, using the @code{offload} @dfn{build
1017 hook}@footnote{This feature is available only when
1018 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1019 present.}. When that
1020 feature is enabled, a list of user-specified build machines is read from
1021 @file{/etc/guix/machines.scm}; every time a build is requested, for
1022 instance via @code{guix build}, the daemon attempts to offload it to one
1023 of the machines that satisfy the constraints of the derivation, in
1024 particular its system type---e.g., @file{x86_64-linux}. Missing
1025 prerequisites for the build are copied over SSH to the target machine,
1026 which then proceeds with the build; upon success the output(s) of the
1027 build are copied back to the initial machine.
1029 The @file{/etc/guix/machines.scm} file typically looks like this:
1032 (list (build-machine
1033 (name "eightysix.example.org")
1034 (system "x86_64-linux")
1035 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1037 (speed 2.)) ;incredibly fast!
1040 (name "meeps.example.org")
1041 (system "mips64el-linux")
1042 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1045 (string-append (getenv "HOME")
1046 "/.ssh/identity-for-guix"))))
1050 In the example above we specify a list of two build machines, one for
1051 the @code{x86_64} architecture and one for the @code{mips64el}
1054 In fact, this file is---not surprisingly!---a Scheme file that is
1055 evaluated when the @code{offload} hook is started. Its return value
1056 must be a list of @code{build-machine} objects. While this example
1057 shows a fixed list of build machines, one could imagine, say, using
1058 DNS-SD to return a list of potential build machines discovered in the
1059 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1060 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1063 @deftp {Data Type} build-machine
1064 This data type represents build machines to which the daemon may offload
1065 builds. The important fields are:
1070 The host name of the remote machine.
1073 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1076 The user account to use when connecting to the remote machine over SSH.
1077 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1078 allow non-interactive logins.
1081 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1082 This is used to authenticate the machine when we connect to it. It is a
1083 long string that looks like this:
1086 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1089 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1090 key can be found in a file such as
1091 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1093 If the machine is running the SSH daemon of GNU@tie{}lsh,
1094 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1095 similar file. It can be converted to the OpenSSH format using
1096 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1099 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1100 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1105 A number of optional fields may be specified:
1109 @item @code{port} (default: @code{22})
1110 Port number of SSH server on the machine.
1112 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1113 The SSH private key file to use when connecting to the machine, in
1114 OpenSSH format. This key must not be protected with a passphrase.
1116 Note that the default value is the private key @emph{of the root
1117 account}. Make sure it exists if you use the default.
1119 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1120 @itemx @code{compression-level} (default: @code{3})
1121 The SSH-level compression methods and compression level requested.
1123 Note that offloading relies on SSH compression to reduce bandwidth usage
1124 when transferring files to and from build machines.
1126 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1127 File name of the Unix-domain socket @command{guix-daemon} is listening
1130 @item @code{parallel-builds} (default: @code{1})
1131 The number of builds that may run in parallel on the machine.
1133 @item @code{speed} (default: @code{1.0})
1134 A ``relative speed factor''. The offload scheduler will tend to prefer
1135 machines with a higher speed factor.
1137 @item @code{features} (default: @code{'()})
1138 A list of strings denoting specific features supported by the machine.
1139 An example is @code{"kvm"} for machines that have the KVM Linux modules
1140 and corresponding hardware support. Derivations can request features by
1141 name, and they will be scheduled on matching build machines.
1146 The @command{guix} command must be in the search path on the build
1147 machines. You can check whether this is the case by running:
1150 ssh build-machine guix repl --version
1153 There is one last thing to do once @file{machines.scm} is in place. As
1154 explained above, when offloading, files are transferred back and forth
1155 between the machine stores. For this to work, you first need to
1156 generate a key pair on each machine to allow the daemon to export signed
1157 archives of files from the store (@pxref{Invoking guix archive}):
1160 # guix archive --generate-key
1164 Each build machine must authorize the key of the master machine so that
1165 it accepts store items it receives from the master:
1168 # guix archive --authorize < master-public-key.txt
1172 Likewise, the master machine must authorize the key of each build machine.
1174 All the fuss with keys is here to express pairwise mutual trust
1175 relations between the master and the build machines. Concretely, when
1176 the master receives files from a build machine (and @i{vice versa}), its
1177 build daemon can make sure they are genuine, have not been tampered
1178 with, and that they are signed by an authorized key.
1180 @cindex offload test
1181 To test whether your setup is operational, run this command on the
1188 This will attempt to connect to each of the build machines specified in
1189 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1190 available on each machine, attempt to export to the machine and import
1191 from it, and report any error in the process.
1193 If you want to test a different machine file, just specify it on the
1197 # guix offload test machines-qualif.scm
1200 Last, you can test the subset of the machines whose name matches a
1201 regular expression like this:
1204 # guix offload test machines.scm '\.gnu\.org$'
1207 @cindex offload status
1208 To display the current load of all build hosts, run this command on the
1212 # guix offload status
1216 @node SELinux Support
1217 @subsection SELinux Support
1219 @cindex SELinux, daemon policy
1220 @cindex mandatory access control, SELinux
1221 @cindex security, guix-daemon
1222 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1223 can be installed on a system where SELinux is enabled, in order to label
1224 Guix files and to specify the expected behavior of the daemon. Since
1225 Guix System does not provide an SELinux base policy, the daemon policy cannot
1226 be used on Guix System.
1228 @subsubsection Installing the SELinux policy
1229 @cindex SELinux, policy installation
1230 To install the policy run this command as root:
1233 semodule -i etc/guix-daemon.cil
1236 Then relabel the file system with @code{restorecon} or by a different
1237 mechanism provided by your system.
1239 Once the policy is installed, the file system has been relabeled, and
1240 the daemon has been restarted, it should be running in the
1241 @code{guix_daemon_t} context. You can confirm this with the following
1245 ps -Zax | grep guix-daemon
1248 Monitor the SELinux log files as you run a command like @code{guix build
1249 hello} to convince yourself that SELinux permits all necessary
1252 @subsubsection Limitations
1253 @cindex SELinux, limitations
1255 This policy is not perfect. Here is a list of limitations or quirks
1256 that should be considered when deploying the provided SELinux policy for
1261 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1262 operations involve contexts that have anything to do with
1263 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1264 but it would be preferrable to define socket rules for only this label.
1267 @code{guix gc} cannot access arbitrary links to profiles. By design,
1268 the file label of the destination of a symlink is independent of the
1269 file label of the link itself. Although all profiles under
1270 $localstatedir are labelled, the links to these profiles inherit the
1271 label of the directory they are in. For links in the user’s home
1272 directory this will be @code{user_home_t}. But for links from the root
1273 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1274 directory, etc, this won’t work. @code{guix gc} would be prevented from
1275 reading and following these links.
1278 The daemon’s feature to listen for TCP connections might no longer work.
1279 This might require extra rules, because SELinux treats network sockets
1280 differently from files.
1283 Currently all files with a name matching the regular expression
1284 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1285 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1286 that name in any profile would be permitted to run in the
1287 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1288 build a package that provides this executable and convince a user to
1289 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1290 At that point SELinux could not prevent it from accessing files that are
1291 allowed for processes in that domain.
1293 We could generate a much more restrictive policy at installation time,
1294 so that only the @emph{exact} file name of the currently installed
1295 @code{guix-daemon} executable would be labelled with
1296 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1297 The downside is that root would have to install or upgrade the policy at
1298 installation time whenever the Guix package that provides the
1299 effectively running @code{guix-daemon} executable is upgraded.
1302 @node Invoking guix-daemon
1303 @section Invoking @command{guix-daemon}
1305 The @command{guix-daemon} program implements all the functionality to
1306 access the store. This includes launching build processes, running the
1307 garbage collector, querying the availability of a build result, etc. It
1308 is normally run as @code{root} like this:
1311 # guix-daemon --build-users-group=guixbuild
1315 For details on how to set it up, @pxref{Setting Up the Daemon}.
1318 @cindex container, build environment
1319 @cindex build environment
1320 @cindex reproducible builds
1321 By default, @command{guix-daemon} launches build processes under
1322 different UIDs, taken from the build group specified with
1323 @code{--build-users-group}. In addition, each build process is run in a
1324 chroot environment that only contains the subset of the store that the
1325 build process depends on, as specified by its derivation
1326 (@pxref{Programming Interface, derivation}), plus a set of specific
1327 system directories. By default, the latter contains @file{/dev} and
1328 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1329 @dfn{container}: in addition to having its own file system tree, it has
1330 a separate mount name space, its own PID name space, network name space,
1331 etc. This helps achieve reproducible builds (@pxref{Features}).
1333 When the daemon performs a build on behalf of the user, it creates a
1334 build directory under @file{/tmp} or under the directory specified by
1335 its @code{TMPDIR} environment variable. This directory is shared with
1336 the container for the duration of the build, though within the container,
1337 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1339 The build directory is automatically deleted upon completion, unless the
1340 build failed and the client specified @option{--keep-failed}
1341 (@pxref{Invoking guix build, @option{--keep-failed}}).
1343 The daemon listens for connections and spawns one sub-process for each session
1344 started by a client (one of the @command{guix} sub-commands.) The
1345 @command{guix processes} command allows you to get an overview of the activity
1346 on your system by viewing each of the active sessions and clients.
1347 @xref{Invoking guix processes}, for more information.
1349 The following command-line options are supported:
1352 @item --build-users-group=@var{group}
1353 Take users from @var{group} to run build processes (@pxref{Setting Up
1354 the Daemon, build users}).
1356 @item --no-substitutes
1358 Do not use substitutes for build products. That is, always build things
1359 locally instead of allowing downloads of pre-built binaries
1360 (@pxref{Substitutes}).
1362 When the daemon runs with @code{--no-substitutes}, clients can still
1363 explicitly enable substitution @i{via} the @code{set-build-options}
1364 remote procedure call (@pxref{The Store}).
1366 @item --substitute-urls=@var{urls}
1367 @anchor{daemon-substitute-urls}
1368 Consider @var{urls} the default whitespace-separated list of substitute
1369 source URLs. When this option is omitted,
1370 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1372 This means that substitutes may be downloaded from @var{urls}, as long
1373 as they are signed by a trusted signature (@pxref{Substitutes}).
1376 @item --no-build-hook
1377 Do not use the @dfn{build hook}.
1379 The build hook is a helper program that the daemon can start and to
1380 which it submits build requests. This mechanism is used to offload
1381 builds to other machines (@pxref{Daemon Offload Setup}).
1383 @item --cache-failures
1384 Cache build failures. By default, only successful builds are cached.
1386 When this option is used, @command{guix gc --list-failures} can be used
1387 to query the set of store items marked as failed; @command{guix gc
1388 --clear-failures} removes store items from the set of cached failures.
1389 @xref{Invoking guix gc}.
1391 @item --cores=@var{n}
1393 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1396 The default value is @code{0}, but it may be overridden by clients, such
1397 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1400 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1401 in the build process, which can then use it to exploit internal
1402 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1404 @item --max-jobs=@var{n}
1406 Allow at most @var{n} build jobs in parallel. The default value is
1407 @code{1}. Setting it to @code{0} means that no builds will be performed
1408 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1409 Setup}), or simply fail.
1411 @item --max-silent-time=@var{seconds}
1412 When the build or substitution process remains silent for more than
1413 @var{seconds}, terminate it and report a build failure.
1415 The default value is @code{0}, which disables the timeout.
1417 The value specified here can be overridden by clients (@pxref{Common
1418 Build Options, @code{--max-silent-time}}).
1420 @item --timeout=@var{seconds}
1421 Likewise, when the build or substitution process lasts for more than
1422 @var{seconds}, terminate it and report a build failure.
1424 The default value is @code{0}, which disables the timeout.
1426 The value specified here can be overridden by clients (@pxref{Common
1427 Build Options, @code{--timeout}}).
1429 @item --rounds=@var{N}
1430 Build each derivation @var{n} times in a row, and raise an error if
1431 consecutive build results are not bit-for-bit identical. Note that this
1432 setting can be overridden by clients such as @command{guix build}
1433 (@pxref{Invoking guix build}).
1435 When used in conjunction with @option{--keep-failed}, the differing
1436 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1437 This makes it easy to look for differences between the two results.
1440 Produce debugging output.
1442 This is useful to debug daemon start-up issues, but then it may be
1443 overridden by clients, for example the @code{--verbosity} option of
1444 @command{guix build} (@pxref{Invoking guix build}).
1446 @item --chroot-directory=@var{dir}
1447 Add @var{dir} to the build chroot.
1449 Doing this may change the result of build processes---for instance if
1450 they use optional dependencies found in @var{dir} when it is available,
1451 and not otherwise. For that reason, it is not recommended to do so.
1452 Instead, make sure that each derivation declares all the inputs that it
1455 @item --disable-chroot
1456 Disable chroot builds.
1458 Using this option is not recommended since, again, it would allow build
1459 processes to gain access to undeclared dependencies. It is necessary,
1460 though, when @command{guix-daemon} is running under an unprivileged user
1463 @item --log-compression=@var{type}
1464 Compress build logs according to @var{type}, one of @code{gzip},
1465 @code{bzip2}, or @code{none}.
1467 Unless @code{--lose-logs} is used, all the build logs are kept in the
1468 @var{localstatedir}. To save space, the daemon automatically compresses
1469 them with bzip2 by default.
1471 @item --disable-deduplication
1472 @cindex deduplication
1473 Disable automatic file ``deduplication'' in the store.
1475 By default, files added to the store are automatically ``deduplicated'':
1476 if a newly added file is identical to another one found in the store,
1477 the daemon makes the new file a hard link to the other file. This can
1478 noticeably reduce disk usage, at the expense of slightly increased
1479 input/output load at the end of a build process. This option disables
1482 @item --gc-keep-outputs[=yes|no]
1483 Tell whether the garbage collector (GC) must keep outputs of live
1487 @cindex garbage collector roots
1488 When set to ``yes'', the GC will keep the outputs of any live derivation
1489 available in the store---the @code{.drv} files. The default is ``no'',
1490 meaning that derivation outputs are kept only if they are reachable from a GC
1491 root. @xref{Invoking guix gc}, for more on GC roots.
1493 @item --gc-keep-derivations[=yes|no]
1494 Tell whether the garbage collector (GC) must keep derivations
1495 corresponding to live outputs.
1497 When set to ``yes'', as is the case by default, the GC keeps
1498 derivations---i.e., @code{.drv} files---as long as at least one of their
1499 outputs is live. This allows users to keep track of the origins of
1500 items in their store. Setting it to ``no'' saves a bit of disk space.
1502 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1503 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1504 ``yes'' causes liveness to flow from derivations to outputs. When both are
1505 set to ``yes'', the effect is to keep all the build prerequisites (the
1506 sources, compiler, libraries, and other build-time tools) of live objects in
1507 the store, regardless of whether these prerequisites are reachable from a GC
1508 root. This is convenient for developers since it saves rebuilds or downloads.
1510 @item --impersonate-linux-2.6
1511 On Linux-based systems, impersonate Linux 2.6. This means that the
1512 kernel's @code{uname} system call will report 2.6 as the release number.
1514 This might be helpful to build programs that (usually wrongfully) depend
1515 on the kernel version number.
1518 Do not keep build logs. By default they are kept under
1519 @code{@var{localstatedir}/guix/log}.
1521 @item --system=@var{system}
1522 Assume @var{system} as the current system type. By default it is the
1523 architecture/kernel pair found at configure time, such as
1524 @code{x86_64-linux}.
1526 @item --listen=@var{endpoint}
1527 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1528 as the file name of a Unix-domain socket if it starts with
1529 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1530 host name or host name and port to listen to. Here are a few examples:
1533 @item --listen=/gnu/var/daemon
1534 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1535 creating it if needed.
1537 @item --listen=localhost
1538 @cindex daemon, remote access
1539 @cindex remote access to the daemon
1540 @cindex daemon, cluster setup
1541 @cindex clusters, daemon setup
1542 Listen for TCP connections on the network interface corresponding to
1543 @code{localhost}, on port 44146.
1545 @item --listen=128.0.0.42:1234
1546 Listen for TCP connections on the network interface corresponding to
1547 @code{128.0.0.42}, on port 1234.
1550 This option can be repeated multiple times, in which case
1551 @command{guix-daemon} accepts connections on all the specified
1552 endpoints. Users can tell client commands what endpoint to connect to
1553 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1554 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1557 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1558 @code{--listen=@var{host}} is suitable on local networks, such as
1559 clusters, where only trusted nodes may connect to the build daemon. In
1560 other cases where remote access to the daemon is needed, we recommend
1561 using Unix-domain sockets along with SSH.
1564 When @code{--listen} is omitted, @command{guix-daemon} listens for
1565 connections on the Unix-domain socket located at
1566 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1570 @node Application Setup
1571 @section Application Setup
1573 @cindex foreign distro
1574 When using Guix on top of GNU/Linux distribution other than Guix System---a
1575 so-called @dfn{foreign distro}---a few additional steps are needed to
1576 get everything in place. Here are some of them.
1580 @anchor{locales-and-locpath}
1581 @cindex locales, when not on Guix System
1583 @vindex GUIX_LOCPATH
1584 Packages installed @i{via} Guix will not use the locale data of the
1585 host system. Instead, you must first install one of the locale packages
1586 available with Guix and then define the @code{GUIX_LOCPATH} environment
1590 $ guix install glibc-locales
1591 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1594 Note that the @code{glibc-locales} package contains data for all the
1595 locales supported by the GNU@tie{}libc and weighs in at around
1596 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1597 limited to a few UTF-8 locales.
1599 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1600 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1601 Manual}). There are two important differences though:
1605 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1606 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1607 to make sure the programs of the foreign distro will not end up loading
1608 incompatible locale data.
1611 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1612 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1613 should your Guix profile contain a mixture of programs linked against
1614 different libc version, each libc version will only try to load locale
1615 data in the right format.
1618 This is important because the locale data format used by different libc
1619 versions may be incompatible.
1621 @subsection Name Service Switch
1623 @cindex name service switch, glibc
1624 @cindex NSS (name service switch), glibc
1625 @cindex nscd (name service caching daemon)
1626 @cindex name service caching daemon (nscd)
1627 When using Guix on a foreign distro, we @emph{strongly recommend} that
1628 the system run the GNU C library's @dfn{name service cache daemon},
1629 @command{nscd}, which should be listening on the
1630 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1631 installed with Guix may fail to look up host names or user accounts, or
1632 may even crash. The next paragraphs explain why.
1634 @cindex @file{nsswitch.conf}
1635 The GNU C library implements a @dfn{name service switch} (NSS), which is
1636 an extensible mechanism for ``name lookups'' in general: host name
1637 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1638 The GNU C Library Reference Manual}).
1640 @cindex Network information service (NIS)
1641 @cindex NIS (Network information service)
1642 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1643 lookup implementations: for example, the @code{nss-mdns} plugin allow
1644 resolution of @code{.local} host names, the @code{nis} plugin allows
1645 user account lookup using the Network information service (NIS), and so
1646 on. These extra ``lookup services'' are configured system-wide in
1647 @file{/etc/nsswitch.conf}, and all the programs running on the system
1648 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1651 When they perform a name lookup---for instance by calling the
1652 @code{getaddrinfo} function in C---applications first try to connect to
1653 the nscd; on success, nscd performs name lookups on their behalf. If
1654 the nscd is not running, then they perform the name lookup by
1655 themselves, by loading the name lookup services into their own address
1656 space and running it. These name lookup services---the
1657 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1658 the host system's C library, rather than from the C library the
1659 application is linked against (the C library coming from Guix).
1661 And this is where the problem is: if your application is linked against
1662 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1663 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1664 likely crash or have its name lookups fail unexpectedly.
1666 Running @command{nscd} on the system, among other advantages, eliminates
1667 this binary incompatibility problem because those @code{libnss_*.so}
1668 files are loaded in the @command{nscd} process, not in applications
1671 @subsection X11 Fonts
1674 The majority of graphical applications use Fontconfig to locate and
1675 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1676 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1677 by default. Thus, to allow graphical applications installed with Guix
1678 to display fonts, you have to install fonts with Guix as well.
1679 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1680 @code{font-gnu-freefont-ttf}.
1682 To display text written in Chinese languages, Japanese, or Korean in
1683 graphical applications, consider installing
1684 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1685 has multiple outputs, one per language family (@pxref{Packages with
1686 Multiple Outputs}). For instance, the following command installs fonts
1687 for Chinese languages:
1690 guix install font-adobe-source-han-sans:cn
1693 @cindex @code{xterm}
1694 Older programs such as @command{xterm} do not use Fontconfig and instead
1695 rely on server-side font rendering. Such programs require to specify a
1696 full name of a font using XLFD (X Logical Font Description), like this:
1699 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1702 To be able to use such full names for the TrueType fonts installed in
1703 your Guix profile, you need to extend the font path of the X server:
1705 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1706 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1708 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1711 @cindex @code{xlsfonts}
1712 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1713 to make sure your TrueType fonts are listed there.
1715 @cindex @code{fc-cache}
1717 After installing fonts you may have to refresh the font cache to use
1718 them in applications. The same applies when applications installed via
1719 Guix do not seem to find fonts. To force rebuilding of the font cache
1720 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1721 @code{fontconfig} package.
1723 @subsection X.509 Certificates
1725 @cindex @code{nss-certs}
1726 The @code{nss-certs} package provides X.509 certificates, which allow
1727 programs to authenticate Web servers accessed over HTTPS.
1729 When using Guix on a foreign distro, you can install this package and
1730 define the relevant environment variables so that packages know where to
1731 look for certificates. @xref{X.509 Certificates}, for detailed
1734 @subsection Emacs Packages
1736 @cindex @code{emacs}
1737 When you install Emacs packages with Guix, the elisp files may be placed
1738 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1740 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1741 directory exists because potentially there may exist thousands of Emacs
1742 packages and storing all their files in a single directory may not be
1743 reliable (because of name conflicts). So we think using a separate
1744 directory for each package is a good idea. It is very similar to how
1745 the Emacs package system organizes the file structure (@pxref{Package
1746 Files,,, emacs, The GNU Emacs Manual}).
1748 By default, Emacs (installed with Guix) ``knows'' where these packages
1749 are placed, so you do not need to perform any configuration. If, for
1750 some reason, you want to avoid auto-loading Emacs packages installed
1751 with Guix, you can do so by running Emacs with @code{--no-site-file}
1752 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1754 @subsection The GCC toolchain
1759 Guix offers individual compiler packages such as @code{gcc} but if you
1760 are in need of a complete toolchain for compiling and linking source
1761 code what you really want is the @code{gcc-toolchain} package. This
1762 package provides a complete GCC toolchain for C/C++ development,
1763 including GCC itself, the GNU C Library (headers and binaries, plus
1764 debugging symbols in the @code{debug} output), Binutils, and a linker
1767 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1768 passed to the linker, add corresponding @code{-rpath} arguments, and
1769 invoke the actual linker with this new set of arguments. You can instruct the
1770 wrapper to refuse to link against libraries not in the store by setting the
1771 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1775 @c *********************************************************************
1776 @node System Installation
1777 @chapter System Installation
1779 @cindex installing Guix System
1780 @cindex Guix System, installation
1781 This section explains how to install Guix System
1782 on a machine. Guix, as a package manager, can
1783 also be installed on top of a running GNU/Linux system,
1784 @pxref{Installation}.
1788 @c This paragraph is for people reading this from tty2 of the
1789 @c installation image.
1790 You are reading this documentation with an Info reader. For details on
1791 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1792 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1793 Info}. Hit @kbd{l} afterwards to come back here.
1795 Alternately, run @command{info info} in another tty to keep the manual
1801 * Limitations:: What you can expect.
1802 * Hardware Considerations:: Supported hardware.
1803 * USB Stick and DVD Installation:: Preparing the installation medium.
1804 * Preparing for Installation:: Networking, partitioning, etc.
1805 * Guided Graphical Installation:: Easy graphical installation.
1806 * Manual Installation:: Manual installation for wizards.
1807 * After System Installation:: When installation succeeded.
1808 * Installing Guix in a VM:: Guix System playground.
1809 * Building the Installation Image:: How this comes to be.
1813 @section Limitations
1815 We consider Guix System to be ready for a wide range of ``desktop'' and server
1816 use cases. The reliability guarantees it provides---transactional upgrades
1817 and rollbacks, reproducibility---make it a solid foundation.
1819 Nevertheless, before you proceed with the installation, be aware of the
1820 following noteworthy limitations applicable to version @value{VERSION}:
1824 Support for the Logical Volume Manager (LVM) is missing.
1827 More and more system services are provided (@pxref{Services}), but some
1831 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1832 as well as a number of X11 window managers. However, KDE is currently
1836 More than a disclaimer, this is an invitation to report issues (and success
1837 stories!), and to join us in improving it. @xref{Contributing}, for more
1841 @node Hardware Considerations
1842 @section Hardware Considerations
1844 @cindex hardware support on Guix System
1845 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1846 builds around the kernel Linux-libre, which means that only hardware for
1847 which free software drivers and firmware exist is supported. Nowadays,
1848 a wide range of off-the-shelf hardware is supported on
1849 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1850 Ethernet controllers. Unfortunately, there are still areas where
1851 hardware vendors deny users control over their own computing, and such
1852 hardware is not supported on Guix System.
1854 @cindex WiFi, hardware support
1855 One of the main areas where free drivers or firmware are lacking is WiFi
1856 devices. WiFi devices known to work include those using Atheros chips
1857 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1858 driver, and those using Broadcom/AirForce chips (BCM43xx with
1859 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1860 Linux-libre driver. Free firmware exists for both and is available
1861 out-of-the-box on Guix System, as part of @code{%base-firmware}
1862 (@pxref{operating-system Reference, @code{firmware}}).
1864 @cindex RYF, Respects Your Freedom
1865 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1866 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1867 certification program for hardware products that respect your freedom
1868 and your privacy and ensure that you have control over your device. We
1869 encourage you to check the list of RYF-certified devices.
1871 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1872 web site. It contains a catalog of hardware devices with information
1873 about their support in GNU/Linux.
1876 @node USB Stick and DVD Installation
1877 @section USB Stick and DVD Installation
1879 An ISO-9660 installation image that can be written to a USB stick or
1880 burnt to a DVD can be downloaded from
1881 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1882 where @var{system} is one of:
1886 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1889 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1892 @c start duplication of authentication part from ``Binary Installation''
1893 Make sure to download the associated @file{.sig} file and to verify the
1894 authenticity of the image against it, along these lines:
1897 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1898 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1901 If that command fails because you do not have the required public key,
1902 then run this command to import it:
1905 $ gpg --keyserver @value{KEY-SERVER} \
1906 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
1910 and rerun the @code{gpg --verify} command.
1913 This image contains the tools necessary for an installation.
1914 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1916 @unnumberedsubsec Copying to a USB Stick
1918 To copy the image to a USB stick, follow these steps:
1922 Decompress the image using the @command{xz} command:
1925 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1929 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1930 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1931 copy the image with:
1934 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1938 Access to @file{/dev/sdX} usually requires root privileges.
1941 @unnumberedsubsec Burning on a DVD
1943 To copy the image to a DVD, follow these steps:
1947 Decompress the image using the @command{xz} command:
1950 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1954 Insert a blank DVD into your machine, and determine
1955 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1956 copy the image with:
1959 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1962 Access to @file{/dev/srX} usually requires root privileges.
1965 @unnumberedsubsec Booting
1967 Once this is done, you should be able to reboot the system and boot from
1968 the USB stick or DVD. The latter usually requires you to get in the
1969 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1971 @xref{Installing Guix in a VM}, if, instead, you would like to install
1972 Guix System in a virtual machine (VM).
1975 @node Preparing for Installation
1976 @section Preparing for Installation
1978 Once you have booted, you can use the guided graphical installer, which makes
1979 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1980 if you are already familiar with GNU/Linux and if you want more control than
1981 what the graphical installer provides, you can choose the ``manual''
1982 installation process (@pxref{Manual Installation}).
1984 The graphical installer is available on TTY1. You can obtain root shells on
1985 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1986 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1987 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1988 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
1989 which allows you to select text with the left mouse button and to paste it
1990 with the middle button.
1993 Installation requires access to the Internet so that any missing
1994 dependencies of your system configuration can be downloaded. See the
1995 ``Networking'' section below.
1998 @node Guided Graphical Installation
1999 @section Guided Graphical Installation
2001 The graphical installer is a text-based user interface. It will guide you,
2002 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2004 The first dialog boxes allow you to set up the system as you use it during the
2005 installation: you can choose the language, keyboard layout, and set up
2006 networking, which will be used during the installation. The image below shows
2007 the networking dialog.
2009 @image{images/installer-network,5in,, networking setup with the graphical installer}
2011 Later steps allow you to partition your hard disk, as shown in the image
2012 below, to choose whether or not to use encrypted file systems, to enter the
2013 host name and root password, and to create an additional account, among other
2016 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2018 Note that, at any time, the installer allows you to exit the current
2019 installation step and resume at a previous step, as show in the image below.
2021 @image{images/installer-resume,5in,, resuming the installation process}
2023 Once you're done, the installer produces an operating system configuration and
2024 displays it (@pxref{Using the Configuration System}). At that point you can
2025 hit ``OK'' and installation will proceed. On success, you can reboot into the
2026 new system and enjoy. @xref{After System Installation}, for what's next!
2029 @node Manual Installation
2030 @section Manual Installation
2032 This section describes how you would ``manually'' install GNU@tie{}Guix System
2033 on your machine. This option requires familiarity with GNU/Linux, with the
2034 shell, and with common administration tools. If you think this is not for
2035 you, consider using the guided graphical installer (@pxref{Guided Graphical
2038 The installation system provides root shells on TTYs 3 to 6; press
2039 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2040 many common tools needed to install the system. But it is also a full-blown
2041 Guix System, which means that you can install additional packages, should you
2042 need it, using @command{guix package} (@pxref{Invoking guix package}).
2045 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2046 * Proceeding with the Installation:: Installing.
2049 @node Keyboard Layout and Networking and Partitioning
2050 @subsection Keyboard Layout, Networking, and Partitioning
2052 Before you can install the system, you may want to adjust the keyboard layout,
2053 set up networking, and partition your target hard disk. This section will
2054 guide you through this.
2056 @subsubsection Keyboard Layout
2058 @cindex keyboard layout
2059 The installation image uses the US qwerty keyboard layout. If you want
2060 to change it, you can use the @command{loadkeys} command. For example,
2061 the following command selects the Dvorak keyboard layout:
2067 See the files under @file{/run/current-system/profile/share/keymaps} for
2068 a list of available keyboard layouts. Run @command{man loadkeys} for
2071 @subsubsection Networking
2073 Run the following command to see what your network interfaces are called:
2080 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2086 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2087 Wired interfaces have a name starting with @samp{e}; for example, the
2088 interface corresponding to the first on-board Ethernet controller is
2089 called @samp{eno1}. Wireless interfaces have a name starting with
2090 @samp{w}, like @samp{w1p2s0}.
2093 @item Wired connection
2094 To configure a wired network run the following command, substituting
2095 @var{interface} with the name of the wired interface you want to use.
2098 ifconfig @var{interface} up
2101 @item Wireless connection
2104 To configure wireless networking, you can create a configuration file
2105 for the @command{wpa_supplicant} configuration tool (its location is not
2106 important) using one of the available text editors such as
2110 nano wpa_supplicant.conf
2113 As an example, the following stanza can go to this file and will work
2114 for many wireless networks, provided you give the actual SSID and
2115 passphrase for the network you are connecting to:
2119 ssid="@var{my-ssid}"
2121 psk="the network's secret passphrase"
2125 Start the wireless service and run it in the background with the
2126 following command (substitute @var{interface} with the name of the
2127 network interface you want to use):
2130 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2133 Run @command{man wpa_supplicant} for more information.
2137 At this point, you need to acquire an IP address. On a network where IP
2138 addresses are automatically assigned @i{via} DHCP, you can run:
2141 dhclient -v @var{interface}
2144 Try to ping a server to see if networking is up and running:
2150 Setting up network access is almost always a requirement because the
2151 image does not contain all the software and tools that may be needed.
2153 @cindex installing over SSH
2154 If you want to, you can continue the installation remotely by starting
2158 herd start ssh-daemon
2161 Make sure to either set a password with @command{passwd}, or configure
2162 OpenSSH public key authentication before logging in.
2164 @subsubsection Disk Partitioning
2166 Unless this has already been done, the next step is to partition, and
2167 then format the target partition(s).
2169 The installation image includes several partitioning tools, including
2170 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2171 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2172 the partition layout you want:
2178 If your disk uses the GUID Partition Table (GPT) format and you plan to
2179 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2180 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2183 @cindex EFI, installation
2184 @cindex UEFI, installation
2185 @cindex ESP, EFI system partition
2186 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2187 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2188 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2191 parted /dev/sda set 1 esp on
2195 @vindex grub-bootloader
2196 @vindex grub-efi-bootloader
2197 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2198 @file{/sys/firmware/efi} exists in the installation image, then you should
2199 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2200 Otherwise you should use the BIOS-based GRUB, known as
2201 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2205 Once you are done partitioning the target hard disk drive, you have to
2206 create a file system on the relevant partition(s)@footnote{Currently
2207 Guix System only supports ext4 and btrfs file systems. In particular, code
2208 that reads file system UUIDs and labels only works for these file system
2209 types.}. For the ESP, if you have one and assuming it is
2210 @file{/dev/sda1}, run:
2213 mkfs.fat -F32 /dev/sda1
2216 Preferably, assign file systems a label so that you can easily and
2217 reliably refer to them in @code{file-system} declarations (@pxref{File
2218 Systems}). This is typically done using the @code{-L} option of
2219 @command{mkfs.ext4} and related commands. So, assuming the target root
2220 partition lives at @file{/dev/sda2}, a file system with the label
2221 @code{my-root} can be created with:
2224 mkfs.ext4 -L my-root /dev/sda2
2227 @cindex encrypted disk
2228 If you are instead planning to encrypt the root partition, you can use
2229 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2230 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2231 @code{man cryptsetup}} for more information.) Assuming you want to
2232 store the root partition on @file{/dev/sda2}, the command sequence would
2233 be along these lines:
2236 cryptsetup luksFormat /dev/sda2
2237 cryptsetup open --type luks /dev/sda2 my-partition
2238 mkfs.ext4 -L my-root /dev/mapper/my-partition
2241 Once that is done, mount the target file system under @file{/mnt}
2242 with a command like (again, assuming @code{my-root} is the label of the
2246 mount LABEL=my-root /mnt
2249 Also mount any other file systems you would like to use on the target
2250 system relative to this path. If you have opted for @file{/boot/efi} as an
2251 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2252 found by @code{guix system init} afterwards.
2254 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2255 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2256 sure to initialize them with @command{mkswap}. Assuming you have one
2257 swap partition on @file{/dev/sda3}, you would run:
2264 Alternatively, you may use a swap file. For example, assuming that in
2265 the new system you want to use the file @file{/swapfile} as a swap file,
2266 you would run@footnote{This example will work for many types of file
2267 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2268 btrfs), the required steps may be different. For details, see the
2269 manual pages for @command{mkswap} and @command{swapon}.}:
2272 # This is 10 GiB of swap space. Adjust "count" to change the size.
2273 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2274 # For security, make the file readable and writable only by root.
2275 chmod 600 /mnt/swapfile
2276 mkswap /mnt/swapfile
2277 swapon /mnt/swapfile
2280 Note that if you have encrypted the root partition and created a swap
2281 file in its file system as described above, then the encryption also
2282 protects the swap file, just like any other file in that file system.
2284 @node Proceeding with the Installation
2285 @subsection Proceeding with the Installation
2287 With the target partitions ready and the target root mounted on
2288 @file{/mnt}, we're ready to go. First, run:
2291 herd start cow-store /mnt
2294 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2295 during the installation phase are written to the target disk on @file{/mnt}
2296 rather than kept in memory. This is necessary because the first phase of
2297 the @command{guix system init} command (see below) entails downloads or
2298 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2300 Next, you have to edit a file and
2301 provide the declaration of the operating system to be installed. To
2302 that end, the installation system comes with three text editors. We
2303 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2304 supports syntax highlighting and parentheses matching; other editors
2305 include GNU Zile (an Emacs clone), and
2306 nvi (a clone of the original BSD @command{vi} editor).
2307 We strongly recommend storing that file on the target root file system, say,
2308 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2309 configuration file once you have rebooted into the newly-installed system.
2311 @xref{Using the Configuration System}, for an overview of the
2312 configuration file. The example configurations discussed in that
2313 section are available under @file{/etc/configuration} in the
2314 installation image. Thus, to get started with a system configuration
2315 providing a graphical display server (a ``desktop'' system), you can run
2316 something along these lines:
2320 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2321 # nano /mnt/etc/config.scm
2324 You should pay attention to what your configuration file contains, and
2329 Make sure the @code{bootloader-configuration} form refers to the target
2330 you want to install GRUB on. It should mention @code{grub-bootloader} if
2331 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2332 for newer UEFI systems. For legacy systems, the @code{target} field
2333 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2334 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2335 currently mounted and a @code{file-system} entry is specified in your
2339 Be sure that your file system labels match the value of their respective
2340 @code{device} fields in your @code{file-system} configuration, assuming
2341 your @code{file-system} configuration uses the @code{file-system-label}
2342 procedure in its @code{device} field.
2345 If there are encrypted or RAID partitions, make sure to add a
2346 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2349 Once you are done preparing the configuration file, the new system must
2350 be initialized (remember that the target root file system is mounted
2354 guix system init /mnt/etc/config.scm /mnt
2358 This copies all the necessary files and installs GRUB on
2359 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2360 more information, @pxref{Invoking guix system}. This command may trigger
2361 downloads or builds of missing packages, which can take some time.
2363 Once that command has completed---and hopefully succeeded!---you can run
2364 @command{reboot} and boot into the new system. The @code{root} password
2365 in the new system is initially empty; other users' passwords need to be
2366 initialized by running the @command{passwd} command as @code{root},
2367 unless your configuration specifies otherwise
2368 (@pxref{user-account-password, user account passwords}).
2369 @xref{After System Installation}, for what's next!
2372 @node After System Installation
2373 @section After System Installation
2375 Success, you've now booted into Guix System! From then on, you can update the
2376 system whenever you want by running, say:
2380 sudo guix system reconfigure /etc/config.scm
2384 This builds a new system generation with the latest packages and services
2385 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2386 your system includes the latest security updates (@pxref{Security Updates}).
2388 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2390 @cindex sudo vs. @command{guix pull}
2391 Note that @command{sudo guix} runs your user's @command{guix} command and
2392 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2393 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2396 Join us on @code{#guix} on the Freenode IRC network or on
2397 @email{guix-devel@@gnu.org} to share your experience!
2400 @node Installing Guix in a VM
2401 @section Installing Guix in a Virtual Machine
2403 @cindex virtual machine, Guix System installation
2404 @cindex virtual private server (VPS)
2405 @cindex VPS (virtual private server)
2406 If you'd like to install Guix System in a virtual machine (VM) or on a
2407 virtual private server (VPS) rather than on your beloved machine, this
2410 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2411 disk image, follow these steps:
2415 First, retrieve and decompress the Guix system installation image as
2416 described previously (@pxref{USB Stick and DVD Installation}).
2419 Create a disk image that will hold the installed system. To make a
2420 qcow2-formatted disk image, use the @command{qemu-img} command:
2423 qemu-img create -f qcow2 guixsd.img 50G
2426 The resulting file will be much smaller than 50 GB (typically less than
2427 1 MB), but it will grow as the virtualized storage device is filled up.
2430 Boot the USB installation image in an VM:
2433 qemu-system-x86_64 -m 1024 -smp 1 \
2434 -net user -net nic,model=virtio -boot menu=on \
2435 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2436 -drive file=guixsd.img
2439 The ordering of the drives matters.
2441 In the VM console, quickly press the @kbd{F12} key to enter the boot
2442 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2446 You're now root in the VM, proceed with the installation process.
2447 @xref{Preparing for Installation}, and follow the instructions.
2450 Once installation is complete, you can boot the system that's on your
2451 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2454 @node Building the Installation Image
2455 @section Building the Installation Image
2457 @cindex installation image
2458 The installation image described above was built using the @command{guix
2459 system} command, specifically:
2462 guix system disk-image --file-system-type=iso9660 \
2463 gnu/system/install.scm
2466 Have a look at @file{gnu/system/install.scm} in the source tree,
2467 and see also @ref{Invoking guix system} for more information
2468 about the installation image.
2470 @section Building the Installation Image for ARM Boards
2472 Many ARM boards require a specific variant of the
2473 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2475 If you build a disk image and the bootloader is not available otherwise
2476 (on another boot drive etc), it's advisable to build an image that
2477 includes the bootloader, specifically:
2480 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2483 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2484 board, a list of possible boards will be printed.
2486 @c *********************************************************************
2487 @node Package Management
2488 @chapter Package Management
2491 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2492 remove software packages, without having to know about their build
2493 procedures or dependencies. Guix also goes beyond this obvious set of
2496 This chapter describes the main features of Guix, as well as the
2497 package management tools it provides. Along with the command-line
2498 interface described below (@pxref{Invoking guix package, @code{guix
2499 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2500 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2501 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2505 guix install emacs-guix
2509 * Features:: How Guix will make your life brighter.
2510 * Invoking guix package:: Package installation, removal, etc.
2511 * Substitutes:: Downloading pre-built binaries.
2512 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2513 * Invoking guix gc:: Running the garbage collector.
2514 * Invoking guix pull:: Fetching the latest Guix and distribution.
2515 * Channels:: Customizing the package collection.
2516 * Inferiors:: Interacting with another revision of Guix.
2517 * Invoking guix describe:: Display information about your Guix revision.
2518 * Invoking guix archive:: Exporting and importing store files.
2524 When using Guix, each package ends up in the @dfn{package store}, in its
2525 own directory---something that resembles
2526 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2528 Instead of referring to these directories, users have their own
2529 @dfn{profile}, which points to the packages that they actually want to
2530 use. These profiles are stored within each user's home directory, at
2531 @code{$HOME/.guix-profile}.
2533 For example, @code{alice} installs GCC 4.7.2. As a result,
2534 @file{/home/alice/.guix-profile/bin/gcc} points to
2535 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2536 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2537 simply continues to point to
2538 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2539 coexist on the same system without any interference.
2541 The @command{guix package} command is the central tool to manage
2542 packages (@pxref{Invoking guix package}). It operates on the per-user
2543 profiles, and can be used @emph{with normal user privileges}.
2545 @cindex transactions
2546 The command provides the obvious install, remove, and upgrade
2547 operations. Each invocation is actually a @emph{transaction}: either
2548 the specified operation succeeds, or nothing happens. Thus, if the
2549 @command{guix package} process is terminated during the transaction,
2550 or if a power outage occurs during the transaction, then the user's
2551 profile remains in its previous state, and remains usable.
2553 In addition, any package transaction may be @emph{rolled back}. So, if,
2554 for example, an upgrade installs a new version of a package that turns
2555 out to have a serious bug, users may roll back to the previous instance
2556 of their profile, which was known to work well. Similarly, the global
2557 system configuration on Guix is subject to
2558 transactional upgrades and roll-back
2559 (@pxref{Using the Configuration System}).
2561 All packages in the package store may be @emph{garbage-collected}.
2562 Guix can determine which packages are still referenced by user
2563 profiles, and remove those that are provably no longer referenced
2564 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2565 generations of their profile so that the packages they refer to can be
2568 @cindex reproducibility
2569 @cindex reproducible builds
2570 Guix takes a @dfn{purely functional} approach to package
2571 management, as described in the introduction (@pxref{Introduction}).
2572 Each @file{/gnu/store} package directory name contains a hash of all the
2573 inputs that were used to build that package---compiler, libraries, build
2574 scripts, etc. This direct correspondence allows users to make sure a
2575 given package installation matches the current state of their
2576 distribution. It also helps maximize @dfn{build reproducibility}:
2577 thanks to the isolated build environments that are used, a given build
2578 is likely to yield bit-identical files when performed on different
2579 machines (@pxref{Invoking guix-daemon, container}).
2582 This foundation allows Guix to support @dfn{transparent binary/source
2583 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2584 available from an external source---a @dfn{substitute}, Guix just
2585 downloads it and unpacks it;
2586 otherwise, it builds the package from source, locally
2587 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2588 reproducible, users do not have to trust servers that provide
2589 substitutes: they can force a local build and @emph{challenge} providers
2590 (@pxref{Invoking guix challenge}).
2592 Control over the build environment is a feature that is also useful for
2593 developers. The @command{guix environment} command allows developers of
2594 a package to quickly set up the right development environment for their
2595 package, without having to manually install the dependencies of the
2596 package into their profile (@pxref{Invoking guix environment}).
2598 @cindex replication, of software environments
2599 @cindex provenance tracking, of software artifacts
2600 All of Guix and its package definitions is version-controlled, and
2601 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2602 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2603 Guix instance on a different machine or at a later point in time, which in
2604 turn allows you to @emph{replicate complete software environments}, while
2605 retaining precise @dfn{provenance tracking} of the software.
2607 @node Invoking guix package
2608 @section Invoking @command{guix package}
2610 @cindex installing packages
2611 @cindex removing packages
2612 @cindex package installation
2613 @cindex package removal
2614 The @command{guix package} command is the tool that allows users to
2615 install, upgrade, and remove packages, as well as rolling back to
2616 previous configurations. It operates only on the user's own profile,
2617 and works with normal user privileges (@pxref{Features}). Its syntax
2621 guix package @var{options}
2624 @cindex transactions
2625 Primarily, @var{options} specifies the operations to be performed during
2626 the transaction. Upon completion, a new profile is created, but
2627 previous @dfn{generations} of the profile remain available, should the user
2630 For example, to remove @code{lua} and install @code{guile} and
2631 @code{guile-cairo} in a single transaction:
2634 guix package -r lua -i guile guile-cairo
2637 @cindex aliases, for @command{guix package}
2638 For your convenience, we also provide the following aliases:
2642 @command{guix search} is an alias for @command{guix package -s},
2644 @command{guix install} is an alias for @command{guix package -i},
2646 @command{guix remove} is an alias for @command{guix package -r},
2648 and @command{guix upgrade} is an alias for @command{guix package -u}.
2651 These aliases are less expressive than @command{guix package} and provide
2652 fewer options, so in some cases you'll probably want to use @command{guix
2655 @command{guix package} also supports a @dfn{declarative approach}
2656 whereby the user specifies the exact set of packages to be available and
2657 passes it @i{via} the @option{--manifest} option
2658 (@pxref{profile-manifest, @option{--manifest}}).
2661 For each user, a symlink to the user's default profile is automatically
2662 created in @file{$HOME/.guix-profile}. This symlink always points to the
2663 current generation of the user's default profile. Thus, users can add
2664 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2665 variable, and so on.
2666 @cindex search paths
2667 If you are not using Guix System, consider adding the
2668 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2669 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2670 shells get all the right environment variable definitions:
2673 GUIX_PROFILE="$HOME/.guix-profile" ; \
2674 source "$HOME/.guix-profile/etc/profile"
2677 In a multi-user setup, user profiles are stored in a place registered as
2678 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2679 to (@pxref{Invoking guix gc}). That directory is normally
2680 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2681 @var{localstatedir} is the value passed to @code{configure} as
2682 @code{--localstatedir}, and @var{user} is the user name. The
2683 @file{per-user} directory is created when @command{guix-daemon} is
2684 started, and the @var{user} sub-directory is created by @command{guix
2687 The @var{options} can be among the following:
2691 @item --install=@var{package} @dots{}
2692 @itemx -i @var{package} @dots{}
2693 Install the specified @var{package}s.
2695 Each @var{package} may specify either a simple package name, such as
2696 @code{guile}, or a package name followed by an at-sign and version number,
2697 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2698 case, the newest version prefixed by @code{1.8} is selected.)
2700 If no version number is specified, the
2701 newest available version will be selected. In addition, @var{package}
2702 may contain a colon, followed by the name of one of the outputs of the
2703 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2704 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2705 name (and optionally version) are searched for among the GNU
2706 distribution modules (@pxref{Package Modules}).
2708 @cindex propagated inputs
2709 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2710 that automatically get installed along with the required package
2711 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2712 @code{package} objects}, for information about propagated inputs in
2713 package definitions).
2715 @anchor{package-cmd-propagated-inputs}
2716 An example is the GNU MPC library: its C header files refer to those of
2717 the GNU MPFR library, which in turn refer to those of the GMP library.
2718 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2719 in the profile; removing MPC also removes MPFR and GMP---unless they had
2720 also been explicitly installed by the user.
2722 Besides, packages sometimes rely on the definition of environment
2723 variables for their search paths (see explanation of
2724 @code{--search-paths} below). Any missing or possibly incorrect
2725 environment variable definitions are reported here.
2727 @item --install-from-expression=@var{exp}
2729 Install the package @var{exp} evaluates to.
2731 @var{exp} must be a Scheme expression that evaluates to a
2732 @code{<package>} object. This option is notably useful to disambiguate
2733 between same-named variants of a package, with expressions such as
2734 @code{(@@ (gnu packages base) guile-final)}.
2736 Note that this option installs the first output of the specified
2737 package, which may be insufficient when needing a specific output of a
2738 multiple-output package.
2740 @item --install-from-file=@var{file}
2741 @itemx -f @var{file}
2742 Install the package that the code within @var{file} evaluates to.
2744 As an example, @var{file} might contain a definition like this
2745 (@pxref{Defining Packages}):
2748 @verbatiminclude package-hello.scm
2751 Developers may find it useful to include such a @file{guix.scm} file
2752 in the root of their project source tree that can be used to test
2753 development snapshots and create reproducible development environments
2754 (@pxref{Invoking guix environment}).
2756 @item --remove=@var{package} @dots{}
2757 @itemx -r @var{package} @dots{}
2758 Remove the specified @var{package}s.
2760 As for @code{--install}, each @var{package} may specify a version number
2761 and/or output name in addition to the package name. For instance,
2762 @code{-r glibc:debug} would remove the @code{debug} output of
2765 @item --upgrade[=@var{regexp} @dots{}]
2766 @itemx -u [@var{regexp} @dots{}]
2767 @cindex upgrading packages
2768 Upgrade all the installed packages. If one or more @var{regexp}s are
2769 specified, upgrade only installed packages whose name matches a
2770 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2772 Note that this upgrades package to the latest version of packages found
2773 in the distribution currently installed. To update your distribution,
2774 you should regularly run @command{guix pull} (@pxref{Invoking guix
2777 @item --do-not-upgrade[=@var{regexp} @dots{}]
2778 When used together with the @code{--upgrade} option, do @emph{not}
2779 upgrade any packages whose name matches a @var{regexp}. For example, to
2780 upgrade all packages in the current profile except those containing the
2781 substring ``emacs'':
2784 $ guix package --upgrade . --do-not-upgrade emacs
2787 @item @anchor{profile-manifest}--manifest=@var{file}
2788 @itemx -m @var{file}
2789 @cindex profile declaration
2790 @cindex profile manifest
2791 Create a new generation of the profile from the manifest object
2792 returned by the Scheme code in @var{file}.
2794 This allows you to @emph{declare} the profile's contents rather than
2795 constructing it through a sequence of @code{--install} and similar
2796 commands. The advantage is that @var{file} can be put under version
2797 control, copied to different machines to reproduce the same profile, and
2800 @c FIXME: Add reference to (guix profile) documentation when available.
2801 @var{file} must return a @dfn{manifest} object, which is roughly a list
2804 @findex packages->manifest
2806 (use-package-modules guile emacs)
2811 ;; Use a specific package output.
2812 (list guile-2.0 "debug")))
2815 @findex specifications->manifest
2816 In this example we have to know which modules define the @code{emacs}
2817 and @code{guile-2.0} variables to provide the right
2818 @code{use-package-modules} line, which can be cumbersome. We can
2819 instead provide regular package specifications and let
2820 @code{specifications->manifest} look up the corresponding package
2824 (specifications->manifest
2825 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2829 @cindex rolling back
2830 @cindex undoing transactions
2831 @cindex transactions, undoing
2832 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2833 the last transaction.
2835 When combined with options such as @code{--install}, roll back occurs
2836 before any other actions.
2838 When rolling back from the first generation that actually contains
2839 installed packages, the profile is made to point to the @dfn{zeroth
2840 generation}, which contains no files apart from its own metadata.
2842 After having rolled back, installing, removing, or upgrading packages
2843 overwrites previous future generations. Thus, the history of the
2844 generations in a profile is always linear.
2846 @item --switch-generation=@var{pattern}
2847 @itemx -S @var{pattern}
2849 Switch to a particular generation defined by @var{pattern}.
2851 @var{pattern} may be either a generation number or a number prefixed
2852 with ``+'' or ``-''. The latter means: move forward/backward by a
2853 specified number of generations. For example, if you want to return to
2854 the latest generation after @code{--roll-back}, use
2855 @code{--switch-generation=+1}.
2857 The difference between @code{--roll-back} and
2858 @code{--switch-generation=-1} is that @code{--switch-generation} will
2859 not make a zeroth generation, so if a specified generation does not
2860 exist, the current generation will not be changed.
2862 @item --search-paths[=@var{kind}]
2863 @cindex search paths
2864 Report environment variable definitions, in Bash syntax, that may be
2865 needed in order to use the set of installed packages. These environment
2866 variables are used to specify @dfn{search paths} for files used by some
2867 of the installed packages.
2869 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2870 environment variables to be defined so it can look for headers and
2871 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2872 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2873 library are installed in the profile, then @code{--search-paths} will
2874 suggest setting these variables to @code{@var{profile}/include} and
2875 @code{@var{profile}/lib}, respectively.
2877 The typical use case is to define these environment variables in the
2881 $ eval `guix package --search-paths`
2884 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2885 meaning that the returned environment variable definitions will either
2886 be exact settings, or prefixes or suffixes of the current value of these
2887 variables. When omitted, @var{kind} defaults to @code{exact}.
2889 This option can also be used to compute the @emph{combined} search paths
2890 of several profiles. Consider this example:
2893 $ guix package -p foo -i guile
2894 $ guix package -p bar -i guile-json
2895 $ guix package -p foo -p bar --search-paths
2898 The last command above reports about the @code{GUILE_LOAD_PATH}
2899 variable, even though, taken individually, neither @file{foo} nor
2900 @file{bar} would lead to that recommendation.
2903 @item --profile=@var{profile}
2904 @itemx -p @var{profile}
2905 Use @var{profile} instead of the user's default profile.
2907 @cindex collisions, in a profile
2908 @cindex colliding packages in profiles
2909 @cindex profile collisions
2910 @item --allow-collisions
2911 Allow colliding packages in the new profile. Use at your own risk!
2913 By default, @command{guix package} reports as an error @dfn{collisions}
2914 in the profile. Collisions happen when two or more different versions
2915 or variants of a given package end up in the profile.
2918 Use the bootstrap Guile to build the profile. This option is only
2919 useful to distribution developers.
2923 In addition to these actions, @command{guix package} supports the
2924 following options to query the current state of a profile, or the
2925 availability of packages:
2929 @item --search=@var{regexp}
2930 @itemx -s @var{regexp}
2931 @cindex searching for packages
2932 List the available packages whose name, synopsis, or description matches
2933 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2934 Print all the metadata of matching packages in
2935 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2936 GNU recutils manual}).
2938 This allows specific fields to be extracted using the @command{recsel}
2939 command, for instance:
2942 $ guix package -s malloc | recsel -p name,version,relevance
2956 Similarly, to show the name of all the packages available under the
2957 terms of the GNU@tie{}LGPL version 3:
2960 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2967 It is also possible to refine search results using several @code{-s} flags to
2968 @command{guix package}, or several arguments to @command{guix search}. For
2969 example, the following command returns a list of board games (this time using
2970 the @command{guix search} alias):
2973 $ guix search '\<board\>' game | recsel -p name
2978 If we were to omit @code{-s game}, we would also get software packages
2979 that deal with printed circuit boards; removing the angle brackets
2980 around @code{board} would further add packages that have to do with
2983 And now for a more elaborate example. The following command searches
2984 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2985 libraries, and prints the name and synopsis of the matching packages:
2988 $ guix search crypto library | \
2989 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
2993 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
2994 information on @dfn{selection expressions} for @code{recsel -e}.
2996 @item --show=@var{package}
2997 Show details about @var{package}, taken from the list of available packages, in
2998 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3002 $ guix package --show=python | recsel -p name,version
3010 You may also specify the full name of a package to only get details about a
3011 specific version of it:
3013 $ guix package --show=python@@3.4 | recsel -p name,version
3020 @item --list-installed[=@var{regexp}]
3021 @itemx -I [@var{regexp}]
3022 List the currently installed packages in the specified profile, with the
3023 most recently installed packages shown last. When @var{regexp} is
3024 specified, list only installed packages whose name matches @var{regexp}.
3026 For each installed package, print the following items, separated by
3027 tabs: the package name, its version string, the part of the package that
3028 is installed (for instance, @code{out} for the default output,
3029 @code{include} for its headers, etc.), and the path of this package in
3032 @item --list-available[=@var{regexp}]
3033 @itemx -A [@var{regexp}]
3034 List packages currently available in the distribution for this system
3035 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3036 installed packages whose name matches @var{regexp}.
3038 For each package, print the following items separated by tabs: its name,
3039 its version string, the parts of the package (@pxref{Packages with
3040 Multiple Outputs}), and the source location of its definition.
3042 @item --list-generations[=@var{pattern}]
3043 @itemx -l [@var{pattern}]
3045 Return a list of generations along with their creation dates; for each
3046 generation, show the installed packages, with the most recently
3047 installed packages shown last. Note that the zeroth generation is never
3050 For each installed package, print the following items, separated by
3051 tabs: the name of a package, its version string, the part of the package
3052 that is installed (@pxref{Packages with Multiple Outputs}), and the
3053 location of this package in the store.
3055 When @var{pattern} is used, the command returns only matching
3056 generations. Valid patterns include:
3059 @item @emph{Integers and comma-separated integers}. Both patterns denote
3060 generation numbers. For instance, @code{--list-generations=1} returns
3063 And @code{--list-generations=1,8,2} outputs three generations in the
3064 specified order. Neither spaces nor trailing commas are allowed.
3066 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3067 specified generations and everything in between. Note that the start of
3068 a range must be smaller than its end.
3070 It is also possible to omit the endpoint. For example,
3071 @code{--list-generations=2..}, returns all generations starting from the
3074 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3075 or months by passing an integer along with the first letter of the
3076 duration. For example, @code{--list-generations=20d} lists generations
3077 that are up to 20 days old.
3080 @item --delete-generations[=@var{pattern}]
3081 @itemx -d [@var{pattern}]
3082 When @var{pattern} is omitted, delete all generations except the current
3085 This command accepts the same patterns as @option{--list-generations}.
3086 When @var{pattern} is specified, delete the matching generations. When
3087 @var{pattern} specifies a duration, generations @emph{older} than the
3088 specified duration match. For instance, @code{--delete-generations=1m}
3089 deletes generations that are more than one month old.
3091 If the current generation matches, it is @emph{not} deleted. Also, the
3092 zeroth generation is never deleted.
3094 Note that deleting generations prevents rolling back to them.
3095 Consequently, this command must be used with care.
3099 Finally, since @command{guix package} may actually start build
3100 processes, it supports all the common build options (@pxref{Common Build
3101 Options}). It also supports package transformation options, such as
3102 @option{--with-source} (@pxref{Package Transformation Options}).
3103 However, note that package transformations are lost when upgrading; to
3104 preserve transformations across upgrades, you should define your own
3105 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3106 (@pxref{Defining Packages}).
3109 @section Substitutes
3112 @cindex pre-built binaries
3113 Guix supports transparent source/binary deployment, which means that it
3114 can either build things locally, or download pre-built items from a
3115 server, or both. We call these pre-built items @dfn{substitutes}---they
3116 are substitutes for local build results. In many cases, downloading a
3117 substitute is much faster than building things locally.
3119 Substitutes can be anything resulting from a derivation build
3120 (@pxref{Derivations}). Of course, in the common case, they are
3121 pre-built package binaries, but source tarballs, for instance, which
3122 also result from derivation builds, can be available as substitutes.
3125 * Official Substitute Server:: One particular source of substitutes.
3126 * Substitute Server Authorization:: How to enable or disable substitutes.
3127 * Substitute Authentication:: How Guix verifies substitutes.
3128 * Proxy Settings:: How to get substitutes via proxy.
3129 * Substitution Failure:: What happens when substitution fails.
3130 * On Trusting Binaries:: How can you trust that binary blob?
3133 @node Official Substitute Server
3134 @subsection Official Substitute Server
3138 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3139 that builds packages from Guix continuously for some
3140 architectures, and makes them available as substitutes. This is the
3141 default source of substitutes; it can be overridden by passing the
3142 @option{--substitute-urls} option either to @command{guix-daemon}
3143 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3144 or to client tools such as @command{guix package}
3145 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3148 Substitute URLs can be either HTTP or HTTPS.
3149 HTTPS is recommended because communications are encrypted; conversely,
3150 using HTTP makes all communications visible to an eavesdropper, who
3151 could use the information gathered to determine, for instance, whether
3152 your system has unpatched security vulnerabilities.
3154 Substitutes from the official build farm are enabled by default when
3155 using Guix System (@pxref{GNU Distribution}). However,
3156 they are disabled by default when using Guix on a foreign distribution,
3157 unless you have explicitly enabled them via one of the recommended
3158 installation steps (@pxref{Installation}). The following paragraphs
3159 describe how to enable or disable substitutes for the official build
3160 farm; the same procedure can also be used to enable substitutes for any
3161 other substitute server.
3163 @node Substitute Server Authorization
3164 @subsection Substitute Server Authorization
3167 @cindex substitutes, authorization thereof
3168 @cindex access control list (ACL), for substitutes
3169 @cindex ACL (access control list), for substitutes
3170 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3172 must add its public key to the access control list (ACL) of archive
3173 imports, using the @command{guix archive} command (@pxref{Invoking guix
3174 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3175 be compromised and to serve genuine substitutes.
3177 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3178 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3179 the installation prefix of Guix. If you installed Guix from source,
3180 make sure you checked the GPG signature of
3181 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3182 Then, you can run something like this:
3185 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3189 Similarly, the @file{hydra.gnu.org.pub} file contains the public key
3190 of an independent build farm also run by the project, reachable at
3191 @indicateurl{https://mirror.hydra.gnu.org}.
3194 Once this is in place, the output of a command like @code{guix build}
3195 should change from something like:
3198 $ guix build emacs --dry-run
3199 The following derivations would be built:
3200 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3201 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3202 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3203 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3211 $ guix build emacs --dry-run
3212 112.3 MB would be downloaded:
3213 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3214 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3215 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3216 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3221 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3222 will be downloaded, when possible, for future builds.
3224 @cindex substitutes, how to disable
3225 The substitute mechanism can be disabled globally by running
3226 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3227 guix-daemon}). It can also be disabled temporarily by passing the
3228 @code{--no-substitutes} option to @command{guix package}, @command{guix
3229 build}, and other command-line tools.
3231 @node Substitute Authentication
3232 @subsection Substitute Authentication
3234 @cindex digital signatures
3235 Guix detects and raises an error when attempting to use a substitute
3236 that has been tampered with. Likewise, it ignores substitutes that are
3237 not signed, or that are not signed by one of the keys listed in the ACL.
3239 There is one exception though: if an unauthorized server provides
3240 substitutes that are @emph{bit-for-bit identical} to those provided by
3241 an authorized server, then the unauthorized server becomes eligible for
3242 downloads. For example, assume we have chosen two substitute servers
3246 --substitute-urls="https://a.example.org https://b.example.org"
3250 @cindex reproducible builds
3251 If the ACL contains only the key for @code{b.example.org}, and if
3252 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3253 then Guix will download substitutes from @code{a.example.org} because it
3254 comes first in the list and can be considered a mirror of
3255 @code{b.example.org}. In practice, independent build machines usually
3256 produce the same binaries, thanks to bit-reproducible builds (see
3259 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3260 (in other words, the server is not authenticated), contrary to what
3261 HTTPS clients such as Web browsers usually do. This is because Guix
3262 authenticates substitute information itself, as explained above, which
3263 is what we care about (whereas X.509 certificates are about
3264 authenticating bindings between domain names and public keys.)
3266 @node Proxy Settings
3267 @subsection Proxy Settings
3270 Substitutes are downloaded over HTTP or HTTPS.
3271 The @code{http_proxy} environment
3272 variable can be set in the environment of @command{guix-daemon} and is
3273 honored for downloads of substitutes. Note that the value of
3274 @code{http_proxy} in the environment where @command{guix build},
3275 @command{guix package}, and other client commands are run has
3276 @emph{absolutely no effect}.
3278 @node Substitution Failure
3279 @subsection Substitution Failure
3281 Even when a substitute for a derivation is available, sometimes the
3282 substitution attempt will fail. This can happen for a variety of
3283 reasons: the substitute server might be offline, the substitute may
3284 recently have been deleted, the connection might have been interrupted,
3287 When substitutes are enabled and a substitute for a derivation is
3288 available, but the substitution attempt fails, Guix will attempt to
3289 build the derivation locally depending on whether or not
3290 @code{--fallback} was given (@pxref{fallback-option,, common build
3291 option @code{--fallback}}). Specifically, if @code{--fallback} was
3292 omitted, then no local build will be performed, and the derivation is
3293 considered to have failed. However, if @code{--fallback} was given,
3294 then Guix will attempt to build the derivation locally, and the success
3295 or failure of the derivation depends on the success or failure of the
3296 local build. Note that when substitutes are disabled or no substitute
3297 is available for the derivation in question, a local build will
3298 @emph{always} be performed, regardless of whether or not
3299 @code{--fallback} was given.
3301 To get an idea of how many substitutes are available right now, you can
3302 try running the @command{guix weather} command (@pxref{Invoking guix
3303 weather}). This command provides statistics on the substitutes provided
3306 @node On Trusting Binaries
3307 @subsection On Trusting Binaries
3309 @cindex trust, of pre-built binaries
3310 Today, each individual's control over their own computing is at the
3311 mercy of institutions, corporations, and groups with enough power and
3312 determination to subvert the computing infrastructure and exploit its
3313 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3314 convenient, we encourage users to also build on their own, or even run
3315 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3316 interesting target. One way to help is by publishing the software you
3317 build using @command{guix publish} so that others have one more choice
3318 of server to download substitutes from (@pxref{Invoking guix publish}).
3320 Guix has the foundations to maximize build reproducibility
3321 (@pxref{Features}). In most cases, independent builds of a given
3322 package or derivation should yield bit-identical results. Thus, through
3323 a diverse set of independent package builds, we can strengthen the
3324 integrity of our systems. The @command{guix challenge} command aims to
3325 help users assess substitute servers, and to assist developers in
3326 finding out about non-deterministic package builds (@pxref{Invoking guix
3327 challenge}). Similarly, the @option{--check} option of @command{guix
3328 build} allows users to check whether previously-installed substitutes
3329 are genuine by rebuilding them locally (@pxref{build-check,
3330 @command{guix build --check}}).
3332 In the future, we want Guix to have support to publish and retrieve
3333 binaries to/from other users, in a peer-to-peer fashion. If you would
3334 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3336 @node Packages with Multiple Outputs
3337 @section Packages with Multiple Outputs
3339 @cindex multiple-output packages
3340 @cindex package outputs
3343 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3344 source package leads to exactly one directory in the store. When running
3345 @command{guix install glibc}, one installs the default output of the
3346 GNU libc package; the default output is called @code{out}, but its name
3347 can be omitted as shown in this command. In this particular case, the
3348 default output of @code{glibc} contains all the C header files, shared
3349 libraries, static libraries, Info documentation, and other supporting
3352 Sometimes it is more appropriate to separate the various types of files
3353 produced from a single source package into separate outputs. For
3354 instance, the GLib C library (used by GTK+ and related packages)
3355 installs more than 20 MiB of reference documentation as HTML pages.
3356 To save space for users who do not need it, the documentation goes to a
3357 separate output, called @code{doc}. To install the main GLib output,
3358 which contains everything but the documentation, one would run:
3364 @cindex documentation
3365 The command to install its documentation is:
3368 guix install glib:doc
3371 Some packages install programs with different ``dependency footprints''.
3372 For instance, the WordNet package installs both command-line tools and
3373 graphical user interfaces (GUIs). The former depend solely on the C
3374 library, whereas the latter depend on Tcl/Tk and the underlying X
3375 libraries. In this case, we leave the command-line tools in the default
3376 output, whereas the GUIs are in a separate output. This allows users
3377 who do not need the GUIs to save space. The @command{guix size} command
3378 can help find out about such situations (@pxref{Invoking guix size}).
3379 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3381 There are several such multiple-output packages in the GNU distribution.
3382 Other conventional output names include @code{lib} for libraries and
3383 possibly header files, @code{bin} for stand-alone programs, and
3384 @code{debug} for debugging information (@pxref{Installing Debugging
3385 Files}). The outputs of a packages are listed in the third column of
3386 the output of @command{guix package --list-available} (@pxref{Invoking
3390 @node Invoking guix gc
3391 @section Invoking @command{guix gc}
3393 @cindex garbage collector
3395 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3396 The @command{guix gc} command allows users to explicitly run the garbage
3397 collector to reclaim space from the @file{/gnu/store} directory. It is
3398 the @emph{only} way to remove files from @file{/gnu/store}---removing
3399 files or directories manually may break it beyond repair!
3402 @cindex garbage collector roots
3403 The garbage collector has a set of known @dfn{roots}: any file under
3404 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3405 cannot be deleted; any other file is considered @dfn{dead} and may be
3406 deleted. The set of garbage collector roots (``GC roots'' for short)
3407 includes default user profiles; by default, the symlinks under
3408 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3409 added with @command{guix build --root}, for example (@pxref{Invoking
3410 guix build}). The @command{guix gc --list-roots} command lists them.
3412 Prior to running @code{guix gc --collect-garbage} to make space, it is
3413 often useful to remove old generations from user profiles; that way, old
3414 package builds referenced by those generations can be reclaimed. This
3415 is achieved by running @code{guix package --delete-generations}
3416 (@pxref{Invoking guix package}).
3418 Our recommendation is to run a garbage collection periodically, or when
3419 you are short on disk space. For instance, to guarantee that at least
3420 5@tie{}GB are available on your disk, simply run:
3426 It is perfectly safe to run as a non-interactive periodic job
3427 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3428 Running @command{guix gc} with no arguments will collect as
3429 much garbage as it can, but that is often inconvenient: you may find
3430 yourself having to rebuild or re-download software that is ``dead'' from
3431 the GC viewpoint but that is necessary to build other pieces of
3432 software---e.g., the compiler tool chain.
3434 The @command{guix gc} command has three modes of operation: it can be
3435 used to garbage-collect any dead files (the default), to delete specific
3436 files (the @code{--delete} option), to print garbage-collector
3437 information, or for more advanced queries. The garbage collection
3438 options are as follows:
3441 @item --collect-garbage[=@var{min}]
3442 @itemx -C [@var{min}]
3443 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3444 sub-directories. This is the default operation when no option is
3447 When @var{min} is given, stop once @var{min} bytes have been collected.
3448 @var{min} may be a number of bytes, or it may include a unit as a
3449 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3450 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3452 When @var{min} is omitted, collect all the garbage.
3454 @item --free-space=@var{free}
3455 @itemx -F @var{free}
3456 Collect garbage until @var{free} space is available under
3457 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3458 as @code{500MiB}, as described above.
3460 When @var{free} or more is already available in @file{/gnu/store}, do
3461 nothing and exit immediately.
3463 @item --delete-generations[=@var{duration}]
3464 @itemx -d [@var{duration}]
3465 Before starting the garbage collection process, delete all the generations
3466 older than @var{duration}, for all the user profiles; when run as root, this
3467 applies to all the profiles @emph{of all the users}.
3469 For example, this command deletes all the generations of all your profiles
3470 that are older than 2 months (except generations that are current), and then
3471 proceeds to free space until at least 10 GiB are available:
3474 guix gc -d 2m -F 10G
3479 Attempt to delete all the store files and directories specified as
3480 arguments. This fails if some of the files are not in the store, or if
3481 they are still live.
3483 @item --list-failures
3484 List store items corresponding to cached build failures.
3486 This prints nothing unless the daemon was started with
3487 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3488 @option{--cache-failures}}).
3491 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3494 @item --clear-failures
3495 Remove the specified store items from the failed-build cache.
3497 Again, this option only makes sense when the daemon is started with
3498 @option{--cache-failures}. Otherwise, it does nothing.
3501 Show the list of dead files and directories still present in the
3502 store---i.e., files and directories no longer reachable from any root.
3505 Show the list of live store files and directories.
3509 In addition, the references among existing store files can be queried:
3515 @cindex package dependencies
3516 List the references (respectively, the referrers) of store files given
3522 List the requisites of the store files passed as arguments. Requisites
3523 include the store files themselves, their references, and the references
3524 of these, recursively. In other words, the returned list is the
3525 @dfn{transitive closure} of the store files.
3527 @xref{Invoking guix size}, for a tool to profile the size of the closure
3528 of an element. @xref{Invoking guix graph}, for a tool to visualize
3529 the graph of references.
3533 Return the derivation(s) leading to the given store items
3534 (@pxref{Derivations}).
3536 For example, this command:
3539 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3543 returns the @file{.drv} file(s) leading to the @code{emacs} package
3544 installed in your profile.
3546 Note that there may be zero matching @file{.drv} files, for instance
3547 because these files have been garbage-collected. There can also be more
3548 than one matching @file{.drv} due to fixed-output derivations.
3551 Lastly, the following options allow you to check the integrity of the
3552 store and to control disk usage.
3556 @item --verify[=@var{options}]
3557 @cindex integrity, of the store
3558 @cindex integrity checking
3559 Verify the integrity of the store.
3561 By default, make sure that all the store items marked as valid in the
3562 database of the daemon actually exist in @file{/gnu/store}.
3564 When provided, @var{options} must be a comma-separated list containing one
3565 or more of @code{contents} and @code{repair}.
3567 When passing @option{--verify=contents}, the daemon computes the
3568 content hash of each store item and compares it against its hash in the
3569 database. Hash mismatches are reported as data corruptions. Because it
3570 traverses @emph{all the files in the store}, this command can take a
3571 long time, especially on systems with a slow disk drive.
3573 @cindex repairing the store
3574 @cindex corruption, recovering from
3575 Using @option{--verify=repair} or @option{--verify=contents,repair}
3576 causes the daemon to try to repair corrupt store items by fetching
3577 substitutes for them (@pxref{Substitutes}). Because repairing is not
3578 atomic, and thus potentially dangerous, it is available only to the
3579 system administrator. A lightweight alternative, when you know exactly
3580 which items in the store are corrupt, is @command{guix build --repair}
3581 (@pxref{Invoking guix build}).
3584 @cindex deduplication
3585 Optimize the store by hard-linking identical files---this is
3586 @dfn{deduplication}.
3588 The daemon performs deduplication after each successful build or archive
3589 import, unless it was started with @code{--disable-deduplication}
3590 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3591 this option is primarily useful when the daemon was running with
3592 @code{--disable-deduplication}.
3596 @node Invoking guix pull
3597 @section Invoking @command{guix pull}
3599 @cindex upgrading Guix
3600 @cindex updating Guix
3601 @cindex @command{guix pull}
3603 Packages are installed or upgraded to the latest version available in
3604 the distribution currently available on your local machine. To update
3605 that distribution, along with the Guix tools, you must run @command{guix
3606 pull}: the command downloads the latest Guix source code and package
3607 descriptions, and deploys it. Source code is downloaded from a
3608 @uref{https://git-scm.com, Git} repository, by default the official
3609 GNU@tie{}Guix repository, though this can be customized.
3611 On completion, @command{guix package} will use packages and package
3612 versions from this just-retrieved copy of Guix. Not only that, but all
3613 the Guix commands and Scheme modules will also be taken from that latest
3614 version. New @command{guix} sub-commands added by the update also
3617 Any user can update their Guix copy using @command{guix pull}, and the
3618 effect is limited to the user who run @command{guix pull}. For
3619 instance, when user @code{root} runs @command{guix pull}, this has no
3620 effect on the version of Guix that user @code{alice} sees, and vice
3623 The result of running @command{guix pull} is a @dfn{profile} available
3624 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3625 make sure to add it to the beginning of your search path so that you use
3626 the latest version, and similarly for the Info manual
3627 (@pxref{Documentation}):
3630 export PATH="$HOME/.config/guix/current/bin:$PATH"
3631 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3634 The @code{--list-generations} or @code{-l} option lists past generations
3635 produced by @command{guix pull}, along with details about their provenance:
3639 Generation 1 Jun 10 2018 00:18:18
3641 repository URL: https://git.savannah.gnu.org/git/guix.git
3642 branch: origin/master
3643 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3645 Generation 2 Jun 11 2018 11:02:49
3647 repository URL: https://git.savannah.gnu.org/git/guix.git
3648 branch: origin/master
3649 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3650 2 new packages: keepalived, libnfnetlink
3651 6 packages upgraded: emacs-nix-mode@@2.0.4,
3652 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3653 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3655 Generation 3 Jun 13 2018 23:31:07 (current)
3657 repository URL: https://git.savannah.gnu.org/git/guix.git
3658 branch: origin/master
3659 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3660 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3661 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3664 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3665 describe the current status of Guix.
3667 This @code{~/.config/guix/current} profile works like any other profile
3668 created by @command{guix package} (@pxref{Invoking guix package}). That
3669 is, you can list generations, roll back to the previous
3670 generation---i.e., the previous Guix---and so on:
3673 $ guix package -p ~/.config/guix/current --roll-back
3674 switched from generation 3 to 2
3675 $ guix package -p ~/.config/guix/current --delete-generations=1
3676 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3679 The @command{guix pull} command is usually invoked with no arguments,
3680 but it supports the following options:
3683 @item --url=@var{url}
3684 @itemx --commit=@var{commit}
3685 @itemx --branch=@var{branch}
3686 Download code for the @code{guix} channel from the specified @var{url}, at the
3687 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3688 string), or @var{branch}.
3690 @cindex @file{channels.scm}, configuration file
3691 @cindex configuration file for channels
3692 These options are provided for convenience, but you can also specify your
3693 configuration in the @file{~/.config/guix/channels.scm} file or using the
3694 @option{--channels} option (see below).
3696 @item --channels=@var{file}
3697 @itemx -C @var{file}
3698 Read the list of channels from @var{file} instead of
3699 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3700 evaluates to a list of channel objects. @xref{Channels}, for more
3705 Display the list of packages added or upgraded since the previous generation.
3707 This is the same information as displayed upon @command{guix pull} completion,
3708 but without ellipses; it is also similar to the output of @command{guix pull
3709 -l} for the last generation (see below).
3711 @item --list-generations[=@var{pattern}]
3712 @itemx -l [@var{pattern}]
3713 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3714 is provided, the subset of generations that match @var{pattern}.
3715 The syntax of @var{pattern} is the same as with @code{guix package
3716 --list-generations} (@pxref{Invoking guix package}).
3718 @xref{Invoking guix describe}, for a way to display information about the
3719 current generation only.
3721 @item --profile=@var{profile}
3722 @itemx -p @var{profile}
3723 Use @var{profile} instead of @file{~/.config/guix/current}.
3727 Show which channel commit(s) would be used and what would be built or
3728 substituted but do not actually do it.
3730 @item --system=@var{system}
3731 @itemx -s @var{system}
3732 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3733 the system type of the build host.
3736 Produce verbose output, writing build logs to the standard error output.
3739 Use the bootstrap Guile to build the latest Guix. This option is only
3740 useful to Guix developers.
3743 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3744 repository and branch to pull from, as well as @emph{additional} repositories
3745 containing package modules that should be deployed. @xref{Channels}, for more
3748 In addition, @command{guix pull} supports all the common build options
3749 (@pxref{Common Build Options}).
3755 @cindex @file{channels.scm}, configuration file
3756 @cindex configuration file for channels
3757 @cindex @command{guix pull}, configuration file
3758 @cindex configuration of @command{guix pull}
3759 Guix and its package collection are updated by running @command{guix pull}
3760 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3761 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3762 customized by defining @dfn{channels} in the
3763 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3764 of a Git repository to be deployed, and @command{guix pull} can be instructed
3765 to pull from one or more channels. In other words, channels can be used to
3766 @emph{customize} and to @emph{extend} Guix, as we will see below.
3768 @subsection Using a Custom Guix Channel
3770 The channel called @code{guix} specifies where Guix itself---its command-line
3771 tools as well as its package collection---should be downloaded. For instance,
3772 suppose you want to update from your own copy of the Guix repository at
3773 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3774 write in @code{~/.config/guix/channels.scm} this specification:
3777 ;; Tell 'guix pull' to use my own repo.
3780 (url "https://example.org/my-guix.git")
3781 (branch "super-hacks")))
3785 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3786 branch of the repository at @code{example.org}.
3788 @subsection Specifying Additional Channels
3790 @cindex extending the package collection (channels)
3791 @cindex personal packages (channels)
3792 @cindex channels, for personal packages
3793 You can also specify @emph{additional channels} to pull from. Let's say you
3794 have a bunch of custom package variants or personal packages that you think
3795 would make little sense to contribute to the Guix project, but would like to
3796 have these packages transparently available to you at the command line. You
3797 would first write modules containing those package definitions (@pxref{Package
3798 Modules}), maintain them in a Git repository, and then you and anyone else can
3799 use it as an additional channel to get packages from. Neat, no?
3801 @c What follows stems from discussions at
3802 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3803 @c earlier discussions on guix-devel@gnu.org.
3805 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3806 publish your personal channel to the world, we would like to share a few words
3811 Before publishing a channel, please consider contributing your package
3812 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3813 to free software of all sorts, and packages in Guix proper are readily
3814 available to all Guix users and benefit from the project's quality assurance
3818 When you maintain package definitions outside Guix, we, Guix developers,
3819 consider that @emph{the compatibility burden is on you}. Remember that
3820 package modules and package definitions are just Scheme code that uses various
3821 programming interfaces (APIs). We want to remain free to change these APIs to
3822 keep improving Guix, possibly in ways that break your channel. We never
3823 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3827 Corollary: if you're using an external channel and that channel breaks, please
3828 @emph{report the issue to the channel authors}, not to the Guix project.
3831 You've been warned! Having said this, we believe external channels are a
3832 practical way to exert your freedom to augment Guix' package collection and to
3833 share your improvements, which are basic tenets of
3834 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3835 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3838 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3839 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3842 @vindex %default-channels
3844 ;; Add my personal packages to those Guix provides.
3846 (name 'my-personal-packages)
3847 (url "https://example.org/personal-packages.git"))
3852 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3853 add a channel the list of channels that the variable @code{%default-channels}
3854 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3855 Manual}). With this file in place, @command{guix pull} builds not only Guix
3856 but also the package modules from your own repository. The result in
3857 @file{~/.config/guix/current} is the union of Guix with your own package
3861 $ guix pull --list-generations
3863 Generation 19 Aug 27 2018 16:20:48
3865 repository URL: https://git.savannah.gnu.org/git/guix.git
3867 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3868 my-personal-packages dd3df5e
3869 repository URL: https://example.org/personal-packages.git
3871 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3872 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3873 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3877 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3878 both Guix and packages from the @code{my-personal-packages} channel. Among
3879 the new and upgraded packages that are listed, some like @code{my-gimp} and
3880 @code{my-emacs-with-cool-features} might come from
3881 @code{my-personal-packages}, while others come from the Guix default channel.
3883 To create a channel, create a Git repository containing your own package
3884 modules and make it available. The repository can contain anything, but a
3885 useful channel will contain Guile modules that export packages. Once you
3886 start using a channel, Guix will behave as if the root directory of that
3887 channel's Git repository has been added to the Guile load path (@pxref{Load
3888 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3889 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3890 module, then the module will be available under the name @code{(my-packages
3891 my-tools)}, and you will be able to use it like any other module
3892 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3894 @cindex dependencies, channels
3895 @cindex meta-data, channels
3896 @subsection Declaring Channel Dependencies
3898 Channel authors may decide to augment a package collection provided by other
3899 channels. They can declare their channel to be dependent on other channels in
3900 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3901 the channel repository.
3903 The meta-data file should contain a simple S-expression like this:
3910 (name some-collection)
3911 (url "https://example.org/first-collection.git"))
3913 (name some-other-collection)
3914 (url "https://example.org/second-collection.git")
3915 (branch "testing"))))
3918 In the above example this channel is declared to depend on two other channels,
3919 which will both be fetched automatically. The modules provided by the channel
3920 will be compiled in an environment where the modules of all these declared
3921 channels are available.
3923 For the sake of reliability and maintainability, you should avoid dependencies
3924 on channels that you don't control, and you should aim to keep the number of
3925 dependencies to a minimum.
3927 @subsection Replicating Guix
3929 @cindex pinning, channels
3930 @cindex replicating Guix
3931 @cindex reproducibility, of Guix
3932 The @command{guix pull --list-generations} output above shows precisely which
3933 commits were used to build this instance of Guix. We can thus replicate it,
3934 say, on another machine, by providing a channel specification in
3935 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3938 ;; Deploy specific commits of my channels of interest.
3941 (url "https://git.savannah.gnu.org/git/guix.git")
3942 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3944 (name 'my-personal-packages)
3945 (url "https://example.org/personal-packages.git")
3946 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3949 The @command{guix describe --format=channels} command can even generate this
3950 list of channels directly (@pxref{Invoking guix describe}).
3952 At this point the two machines run the @emph{exact same Guix}, with access to
3953 the @emph{exact same packages}. The output of @command{guix build gimp} on
3954 one machine will be exactly the same, bit for bit, as the output of the same
3955 command on the other machine. It also means both machines have access to all
3956 the source code of Guix and, transitively, to all the source code of every
3959 This gives you super powers, allowing you to track the provenance of binary
3960 artifacts with very fine grain, and to reproduce software environments at
3961 will---some sort of ``meta reproducibility'' capabilities, if you will.
3962 @xref{Inferiors}, for another way to take advantage of these super powers.
3967 @c TODO: Remove this once we're more confident about API stability.
3969 The functionality described here is a ``technology preview'' as of version
3970 @value{VERSION}. As such, the interface is subject to change.
3974 @cindex composition of Guix revisions
3975 Sometimes you might need to mix packages from the revision of Guix you're
3976 currently running with packages available in a different revision of Guix.
3977 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3978 revisions in arbitrary ways.
3980 @cindex inferior packages
3981 Technically, an ``inferior'' is essentially a separate Guix process connected
3982 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
3983 @code{(guix inferior)} module allows you to create inferiors and to
3984 communicate with them. It also provides a high-level interface to browse and
3985 manipulate the packages that an inferior provides---@dfn{inferior packages}.
3987 When combined with channels (@pxref{Channels}), inferiors provide a simple way
3988 to interact with a separate revision of Guix. For example, let's assume you
3989 want to install in your profile the current @code{guile} package, along with
3990 the @code{guile-json} as it existed in an older revision of Guix---perhaps
3991 because the newer @code{guile-json} has an incompatible API and you want to
3992 run your code against the old API@. To do that, you could write a manifest for
3993 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
3994 manifest, you would create an inferior for that old Guix revision you care
3995 about, and you would look up the @code{guile-json} package in the inferior:
3998 (use-modules (guix inferior) (guix channels)
3999 (srfi srfi-1)) ;for 'first'
4002 ;; This is the old revision from which we want to
4003 ;; extract guile-json.
4006 (url "https://git.savannah.gnu.org/git/guix.git")
4008 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4011 ;; An inferior representing the above revision.
4012 (inferior-for-channels channels))
4014 ;; Now create a manifest with the current "guile" package
4015 ;; and the old "guile-json" package.
4017 (list (first (lookup-inferior-packages inferior "guile-json"))
4018 (specification->package "guile")))
4021 On its first run, @command{guix package --manifest} might have to build the
4022 channel you specified before it can create the inferior; subsequent runs will
4023 be much faster because the Guix revision will be cached.
4025 The @code{(guix inferior)} module provides the following procedures to open an
4028 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4029 [#:cache-directory] [#:ttl]
4030 Return an inferior for @var{channels}, a list of channels. Use the cache at
4031 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4032 This procedure opens a new connection to the build daemon.
4034 As a side effect, this procedure may build or substitute binaries for
4035 @var{channels}, which can take time.
4038 @deffn {Scheme Procedure} open-inferior @var{directory} @
4039 [#:command "bin/guix"]
4040 Open the inferior Guix in @var{directory}, running
4041 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4042 the inferior could not be launched.
4045 @cindex inferior packages
4046 The procedures listed below allow you to obtain and manipulate inferior
4049 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4050 Return the list of packages known to @var{inferior}.
4053 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4055 Return the sorted list of inferior packages matching @var{name} in
4056 @var{inferior}, with highest version numbers first. If @var{version} is true,
4057 return only packages with a version number prefixed by @var{version}.
4060 @deffn {Scheme Procedure} inferior-package? @var{obj}
4061 Return true if @var{obj} is an inferior package.
4064 @deffn {Scheme Procedure} inferior-package-name @var{package}
4065 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4066 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4067 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4068 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4069 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4070 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4071 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4072 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4073 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4074 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4075 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4076 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4077 These procedures are the counterpart of package record accessors
4078 (@pxref{package Reference}). Most of them work by querying the inferior
4079 @var{package} comes from, so the inferior must still be live when you call
4083 Inferior packages can be used transparently like any other package or
4084 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4085 transparently handled by the @code{packages->manifest} procedure, which is
4086 commonly use in manifests (@pxref{Invoking guix package, the
4087 @option{--manifest} option of @command{guix package}}). Thus you can insert
4088 an inferior package pretty much anywhere you would insert a regular package:
4089 in manifests, in the @code{packages} field of your @code{operating-system}
4090 declaration, and so on.
4092 @node Invoking guix describe
4093 @section Invoking @command{guix describe}
4095 @cindex reproducibility
4096 @cindex replicating Guix
4097 Often you may want to answer questions like: ``Which revision of Guix am I
4098 using?'' or ``Which channels am I using?'' This is useful information in many
4099 situations: if you want to @emph{replicate} an environment on a different
4100 machine or user account, if you want to report a bug or to determine what
4101 change in the channels you are using caused it, or if you want to record your
4102 system state for reproducibility purposes. The @command{guix describe}
4103 command answers these questions.
4105 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4106 displays the channel(s) that it was built from, including their repository URL
4107 and commit IDs (@pxref{Channels}):
4111 Generation 10 Sep 03 2018 17:32:44 (current)
4113 repository URL: https://git.savannah.gnu.org/git/guix.git
4115 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4118 If you're familiar with the Git version control system, this is similar in
4119 spirit to @command{git describe}; the output is also similar to that of
4120 @command{guix pull --list-generations}, but limited to the current generation
4121 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4122 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4123 information is all it takes to describe the revision of Guix you're using, and
4124 also to replicate it.
4126 To make it easier to replicate Guix, @command{guix describe} can also be asked
4127 to return a list of channels instead of the human-readable description above:
4130 $ guix describe -f channels
4133 (url "https://git.savannah.gnu.org/git/guix.git")
4135 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4139 You can save this to a file and feed it to @command{guix pull -C} on some
4140 other machine or at a later point in time, which will instantiate @emph{this
4141 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4142 From there on, since you're able to deploy the same revision of Guix, you can
4143 just as well @emph{replicate a complete software environment}. We humbly
4144 think that this is @emph{awesome}, and we hope you'll like it too!
4146 The details of the options supported by @command{guix describe} are as
4150 @item --format=@var{format}
4151 @itemx -f @var{format}
4152 Produce output in the specified @var{format}, one of:
4156 produce human-readable output;
4158 produce a list of channel specifications that can be passed to @command{guix
4159 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4163 produce a list of channel specifications in JSON format;
4165 produce a list of channel specifications in Recutils format.
4168 @item --profile=@var{profile}
4169 @itemx -p @var{profile}
4170 Display information about @var{profile}.
4173 @node Invoking guix archive
4174 @section Invoking @command{guix archive}
4176 @cindex @command{guix archive}
4178 The @command{guix archive} command allows users to @dfn{export} files
4179 from the store into a single archive, and to later @dfn{import} them on
4180 a machine that runs Guix.
4181 In particular, it allows store files to be transferred from one machine
4182 to the store on another machine.
4185 If you're looking for a way to produce archives in a format suitable for
4186 tools other than Guix, @pxref{Invoking guix pack}.
4189 @cindex exporting store items
4190 To export store files as an archive to standard output, run:
4193 guix archive --export @var{options} @var{specifications}...
4196 @var{specifications} may be either store file names or package
4197 specifications, as for @command{guix package} (@pxref{Invoking guix
4198 package}). For instance, the following command creates an archive
4199 containing the @code{gui} output of the @code{git} package and the main
4200 output of @code{emacs}:
4203 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4206 If the specified packages are not built yet, @command{guix archive}
4207 automatically builds them. The build process may be controlled with the
4208 common build options (@pxref{Common Build Options}).
4210 To transfer the @code{emacs} package to a machine connected over SSH,
4214 guix archive --export -r emacs | ssh the-machine guix archive --import
4218 Similarly, a complete user profile may be transferred from one machine
4219 to another like this:
4222 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4223 ssh the-machine guix archive --import
4227 However, note that, in both examples, all of @code{emacs} and the
4228 profile as well as all of their dependencies are transferred (due to
4229 @code{-r}), regardless of what is already available in the store on the
4230 target machine. The @code{--missing} option can help figure out which
4231 items are missing from the target store. The @command{guix copy}
4232 command simplifies and optimizes this whole process, so this is probably
4233 what you should use in this case (@pxref{Invoking guix copy}).
4235 @cindex nar, archive format
4236 @cindex normalized archive (nar)
4237 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4238 comparable in spirit to `tar', but with differences
4239 that make it more appropriate for our purposes. First, rather than
4240 recording all Unix metadata for each file, the nar format only mentions
4241 the file type (regular, directory, or symbolic link); Unix permissions
4242 and owner/group are dismissed. Second, the order in which directory
4243 entries are stored always follows the order of file names according to
4244 the C locale collation order. This makes archive production fully
4247 When exporting, the daemon digitally signs the contents of the archive,
4248 and that digital signature is appended. When importing, the daemon
4249 verifies the signature and rejects the import in case of an invalid
4250 signature or if the signing key is not authorized.
4251 @c FIXME: Add xref to daemon doc about signatures.
4253 The main options are:
4257 Export the specified store files or packages (see below.) Write the
4258 resulting archive to the standard output.
4260 Dependencies are @emph{not} included in the output, unless
4261 @code{--recursive} is passed.
4265 When combined with @code{--export}, this instructs @command{guix
4266 archive} to include dependencies of the given items in the archive.
4267 Thus, the resulting archive is self-contained: it contains the closure
4268 of the exported store items.
4271 Read an archive from the standard input, and import the files listed
4272 therein into the store. Abort if the archive has an invalid digital
4273 signature, or if it is signed by a public key not among the authorized
4274 keys (see @code{--authorize} below.)
4277 Read a list of store file names from the standard input, one per line,
4278 and write on the standard output the subset of these files missing from
4281 @item --generate-key[=@var{parameters}]
4282 @cindex signing, archives
4283 Generate a new key pair for the daemon. This is a prerequisite before
4284 archives can be exported with @code{--export}. Note that this operation
4285 usually takes time, because it needs to gather enough entropy to
4286 generate the key pair.
4288 The generated key pair is typically stored under @file{/etc/guix}, in
4289 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4290 key, which must be kept secret.) When @var{parameters} is omitted,
4291 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4292 versions before 1.6.0, it is a 4096-bit RSA key.
4293 Alternatively, @var{parameters} can specify
4294 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4295 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4296 Libgcrypt Reference Manual}).
4299 @cindex authorizing, archives
4300 Authorize imports signed by the public key passed on standard input.
4301 The public key must be in ``s-expression advanced format''---i.e., the
4302 same format as the @file{signing-key.pub} file.
4304 The list of authorized keys is kept in the human-editable file
4305 @file{/etc/guix/acl}. The file contains
4306 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4307 s-expressions''} and is structured as an access-control list in the
4308 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4311 @item --extract=@var{directory}
4312 @itemx -x @var{directory}
4313 Read a single-item archive as served by substitute servers
4314 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4315 low-level operation needed in only very narrow use cases; see below.
4317 For example, the following command extracts the substitute for Emacs
4318 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4322 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4323 | bunzip2 | guix archive -x /tmp/emacs
4326 Single-item archives are different from multiple-item archives produced
4327 by @command{guix archive --export}; they contain a single store item,
4328 and they do @emph{not} embed a signature. Thus this operation does
4329 @emph{no} signature verification and its output should be considered
4332 The primary purpose of this operation is to facilitate inspection of
4333 archive contents coming from possibly untrusted substitute servers.
4338 @c *********************************************************************
4340 @chapter Development
4342 @cindex software development
4343 If you are a software developer, Guix provides tools that you should find
4344 helpful---independently of the language you're developing in. This is what
4345 this chapter is about.
4347 The @command{guix environment} command provides a convenient way to set up
4348 @dfn{development environments} containing all the dependencies and tools
4349 necessary to work on the software package of your choice. The @command{guix
4350 pack} command allows you to create @dfn{application bundles} that can be
4351 easily distributed to users who do not run Guix.
4354 * Invoking guix environment:: Setting up development environments.
4355 * Invoking guix pack:: Creating software bundles.
4358 @node Invoking guix environment
4359 @section Invoking @command{guix environment}
4361 @cindex reproducible build environments
4362 @cindex development environments
4363 @cindex @command{guix environment}
4364 @cindex environment, package build environment
4365 The purpose of @command{guix environment} is to assist hackers in
4366 creating reproducible development environments without polluting their
4367 package profile. The @command{guix environment} tool takes one or more
4368 packages, builds all of their inputs, and creates a shell
4369 environment to use them.
4371 The general syntax is:
4374 guix environment @var{options} @var{package}@dots{}
4377 The following example spawns a new shell set up for the development of
4381 guix environment guile
4384 If the needed dependencies are not built yet, @command{guix environment}
4385 automatically builds them. The environment of the new shell is an augmented
4386 version of the environment that @command{guix environment} was run in.
4387 It contains the necessary search paths for building the given package
4388 added to the existing environment variables. To create a ``pure''
4389 environment, in which the original environment variables have been unset,
4390 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4391 environment variables such as @code{PATH} in their @file{~/.bashrc}
4392 file. As a consequence, when @code{guix environment} launches it, Bash
4393 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4394 environment variables. It is an error to define such environment
4395 variables in @file{.bashrc}; instead, they should be defined in
4396 @file{.bash_profile}, which is sourced only by log-in shells.
4397 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4398 details on Bash start-up files.}.
4400 @vindex GUIX_ENVIRONMENT
4401 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4402 variable in the shell it spawns; its value is the file name of the
4403 profile of this environment. This allows users to, say, define a
4404 specific prompt for development environments in their @file{.bashrc}
4405 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4408 if [ -n "$GUIX_ENVIRONMENT" ]
4410 export PS1="\u@@\h \w [dev]\$ "
4415 ...@: or to browse the profile:
4418 $ ls "$GUIX_ENVIRONMENT/bin"
4421 Additionally, more than one package may be specified, in which case the
4422 union of the inputs for the given packages are used. For example, the
4423 command below spawns a shell where all of the dependencies of both Guile
4424 and Emacs are available:
4427 guix environment guile emacs
4430 Sometimes an interactive shell session is not desired. An arbitrary
4431 command may be invoked by placing the @code{--} token to separate the
4432 command from the rest of the arguments:
4435 guix environment guile -- make -j4
4438 In other situations, it is more convenient to specify the list of
4439 packages needed in the environment. For example, the following command
4440 runs @command{python} from an environment containing Python@tie{}2.7 and
4444 guix environment --ad-hoc python2-numpy python-2.7 -- python
4447 Furthermore, one might want the dependencies of a package and also some
4448 additional packages that are not build-time or runtime dependencies, but
4449 are useful when developing nonetheless. Because of this, the
4450 @code{--ad-hoc} flag is positional. Packages appearing before
4451 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4452 added to the environment. Packages appearing after are interpreted as
4453 packages that will be added to the environment directly. For example,
4454 the following command creates a Guix development environment that
4455 additionally includes Git and strace:
4458 guix environment guix --ad-hoc git strace
4461 Sometimes it is desirable to isolate the environment as much as
4462 possible, for maximal purity and reproducibility. In particular, when
4463 using Guix on a host distro that is not Guix System, it is desirable to
4464 prevent access to @file{/usr/bin} and other system-wide resources from
4465 the development environment. For example, the following command spawns
4466 a Guile REPL in a ``container'' where only the store and the current
4467 working directory are mounted:
4470 guix environment --ad-hoc --container guile -- guile
4474 The @code{--container} option requires Linux-libre 3.19 or newer.
4477 The available options are summarized below.
4480 @item --root=@var{file}
4481 @itemx -r @var{file}
4482 @cindex persistent environment
4483 @cindex garbage collector root, for environments
4484 Make @var{file} a symlink to the profile for this environment, and
4485 register it as a garbage collector root.
4487 This is useful if you want to protect your environment from garbage
4488 collection, to make it ``persistent''.
4490 When this option is omitted, the environment is protected from garbage
4491 collection only for the duration of the @command{guix environment}
4492 session. This means that next time you recreate the same environment,
4493 you could have to rebuild or re-download packages. @xref{Invoking guix
4494 gc}, for more on GC roots.
4496 @item --expression=@var{expr}
4497 @itemx -e @var{expr}
4498 Create an environment for the package or list of packages that
4499 @var{expr} evaluates to.
4501 For example, running:
4504 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4507 starts a shell with the environment for this specific variant of the
4513 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4516 starts a shell with all the base system packages available.
4518 The above commands only use the default output of the given packages.
4519 To select other outputs, two element tuples can be specified:
4522 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
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.
4530 As an example, @var{file} might contain a definition like this
4531 (@pxref{Defining Packages}):
4534 @verbatiminclude environment-gdb.scm
4537 @item --manifest=@var{file}
4538 @itemx -m @var{file}
4539 Create an environment for the packages contained in the manifest object
4540 returned by the Scheme code in @var{file}.
4542 This is similar to the same-named option in @command{guix package}
4543 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4547 Include all specified packages in the resulting environment, as if an
4548 @i{ad hoc} package were defined with them as inputs. This option is
4549 useful for quickly creating an environment without having to write a
4550 package expression to contain the desired inputs.
4552 For instance, the command:
4555 guix environment --ad-hoc guile guile-sdl -- guile
4558 runs @command{guile} in an environment where Guile and Guile-SDL are
4561 Note that this example implicitly asks for the default output of
4562 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4563 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4564 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4566 This option may be composed with the default behavior of @command{guix
4567 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4568 as packages whose dependencies will be added to the environment, the
4569 default behavior. Packages appearing after are interpreted as packages
4570 that will be added to the environment directly.
4573 Unset existing environment variables when building the new environment, except
4574 those specified with @option{--preserve} (see below.) This has the effect of
4575 creating an environment in which search paths only contain package inputs.
4577 @item --preserve=@var{regexp}
4578 @itemx -E @var{regexp}
4579 When used alongside @option{--pure}, preserve the environment variables
4580 matching @var{regexp}---in other words, put them on a ``white list'' of
4581 environment variables that must be preserved. This option can be repeated
4585 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4589 This example runs @command{mpirun} in a context where the only environment
4590 variables defined are @code{PATH}, environment variables whose name starts
4591 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4594 @item --search-paths
4595 Display the environment variable definitions that make up the
4598 @item --system=@var{system}
4599 @itemx -s @var{system}
4600 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4605 Run @var{command} within an isolated container. The current working
4606 directory outside the container is mapped inside the container.
4607 Additionally, unless overridden with @code{--user}, a dummy home
4608 directory is created that matches the current user's home directory, and
4609 @file{/etc/passwd} is configured accordingly.
4611 The spawned process runs as the current user outside the container. Inside
4612 the container, it has the same UID and GID as the current user, unless
4613 @option{--user} is passed (see below.)
4617 For containers, share the network namespace with the host system.
4618 Containers created without this flag only have access to the loopback
4621 @item --link-profile
4623 For containers, link the environment profile to
4624 @file{~/.guix-profile} within the container. This is equivalent to
4625 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4626 within the container. Linking will fail and abort the environment if
4627 the directory already exists, which will certainly be the case if
4628 @command{guix environment} was invoked in the user's home directory.
4630 Certain packages are configured to look in
4631 @code{~/.guix-profile} for configuration files and data;@footnote{For
4632 example, the @code{fontconfig} package inspects
4633 @file{~/.guix-profile/share/fonts} for additional fonts.}
4634 @code{--link-profile} allows these programs to behave as expected within
4637 @item --user=@var{user}
4638 @itemx -u @var{user}
4639 For containers, use the username @var{user} in place of the current
4640 user. The generated @file{/etc/passwd} entry within the container will
4641 contain the name @var{user}, the home directory will be
4642 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4643 the UID and GID inside the container are 1000. @var{user}
4644 need not exist on the system.
4646 Additionally, any shared or exposed path (see @code{--share} and
4647 @code{--expose} respectively) whose target is within the current user's
4648 home directory will be remapped relative to @file{/home/USER}; this
4649 includes the automatic mapping of the current working directory.
4652 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4654 guix environment --container --user=foo \
4655 --expose=$HOME/test \
4656 --expose=/tmp/target=$HOME/target
4659 While this will limit the leaking of user identity through home paths
4660 and each of the user fields, this is only one useful component of a
4661 broader privacy/anonymity solution---not one in and of itself.
4663 @item --expose=@var{source}[=@var{target}]
4664 For containers, expose the file system @var{source} from the host system
4665 as the read-only file system @var{target} within the container. If
4666 @var{target} is not specified, @var{source} is used as the target mount
4667 point in the container.
4669 The example below spawns a Guile REPL in a container in which the user's
4670 home directory is accessible read-only via the @file{/exchange}
4674 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4677 @item --share=@var{source}[=@var{target}]
4678 For containers, share the file system @var{source} from the host system
4679 as the writable file system @var{target} within the container. If
4680 @var{target} is not specified, @var{source} is used as the target mount
4681 point in the container.
4683 The example below spawns a Guile REPL in a container in which the user's
4684 home directory is accessible for both reading and writing via the
4685 @file{/exchange} directory:
4688 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4692 @command{guix environment}
4693 also supports all of the common build options that @command{guix
4694 build} supports (@pxref{Common Build Options}) as well as package
4695 transformation options (@pxref{Package Transformation Options}).
4697 @node Invoking guix pack
4698 @section Invoking @command{guix pack}
4700 Occasionally you want to pass software to people who are not (yet!)
4701 lucky enough to be using Guix. You'd tell them to run @command{guix
4702 package -i @var{something}}, but that's not possible in this case. This
4703 is where @command{guix pack} comes in.
4706 If you are looking for ways to exchange binaries among machines that
4707 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4708 publish}, and @ref{Invoking guix archive}.
4713 @cindex application bundle
4714 @cindex software bundle
4715 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4716 @dfn{software bundle}: it creates a tarball or some other archive
4717 containing the binaries of the software you're interested in, and all
4718 its dependencies. The resulting archive can be used on any machine that
4719 does not have Guix, and people can run the exact same binaries as those
4720 you have with Guix. The pack itself is created in a bit-reproducible
4721 fashion, so anyone can verify that it really contains the build results
4722 that you pretend to be shipping.
4724 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4725 their dependencies, you can run:
4728 $ guix pack guile emacs geiser
4730 /gnu/store/@dots{}-pack.tar.gz
4733 The result here is a tarball containing a @file{/gnu/store} directory
4734 with all the relevant packages. The resulting tarball contains a
4735 @dfn{profile} with the three packages of interest; the profile is the
4736 same as would be created by @command{guix package -i}. It is this
4737 mechanism that is used to create Guix's own standalone binary tarball
4738 (@pxref{Binary Installation}).
4740 Users of this pack would have to run
4741 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4742 find inconvenient. To work around it, you can create, say, a
4743 @file{/opt/gnu/bin} symlink to the profile:
4746 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4750 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4752 @cindex relocatable binaries, with @command{guix pack}
4753 What if the recipient of your pack does not have root privileges on
4754 their machine, and thus cannot unpack it in the root file system? In
4755 that case, you will want to use the @code{--relocatable} option (see
4756 below). This option produces @dfn{relocatable binaries}, meaning they
4757 they can be placed anywhere in the file system hierarchy: in the example
4758 above, users can unpack your tarball in their home directory and
4759 directly run @file{./opt/gnu/bin/guile}.
4761 @cindex Docker, build an image with guix pack
4762 Alternatively, you can produce a pack in the Docker image format using
4763 the following command:
4766 guix pack -f docker guile emacs geiser
4770 The result is a tarball that can be passed to the @command{docker load}
4772 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4773 documentation} for more information.
4775 @cindex Singularity, build an image with guix pack
4776 @cindex SquashFS, build an image with guix pack
4777 Yet another option is to produce a SquashFS image with the following
4781 guix pack -f squashfs guile emacs geiser
4785 The result is a SquashFS file system image that can either be mounted or
4786 directly be used as a file system container image with the
4787 @uref{https://singularity.lbl.gov, Singularity container execution
4788 environment}, using commands like @command{singularity shell} or
4789 @command{singularity exec}.
4791 Several command-line options allow you to customize your pack:
4794 @item --format=@var{format}
4795 @itemx -f @var{format}
4796 Produce a pack in the given @var{format}.
4798 The available formats are:
4802 This is the default format. It produces a tarball containing all the
4803 specified binaries and symlinks.
4806 This produces a tarball that follows the
4807 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4808 Docker Image Specification}.
4811 This produces a SquashFS image containing all the specified binaries and
4812 symlinks, as well as empty mount points for virtual file systems like
4816 @cindex relocatable binaries
4819 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4820 anywhere in the file system hierarchy and run from there.
4822 When this option is passed once, the resulting binaries require support for
4823 @dfn{user namespaces} in the kernel Linux; when passed
4824 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4825 PRoot support, can be thought of as the abbreviation of ``Really
4826 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4827 if user namespaces are unavailable, and essentially work anywhere---see below
4828 for the implications.
4830 For example, if you create a pack containing Bash with:
4833 guix pack -RR -S /mybin=bin bash
4837 ...@: you can copy that pack to a machine that lacks Guix, and from your
4838 home directory as a normal user, run:
4846 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4847 @file{/gnu/store} shows up and contains all the dependencies of
4848 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4849 altogether! That is probably the simplest way to deploy Guix-built
4850 software on a non-Guix machine.
4853 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4854 the kernel Linux, which allows unprivileged users to mount or change root.
4855 Old versions of Linux did not support it, and some GNU/Linux distributions
4858 To produce relocatable binaries that work even in the absence of user
4859 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4860 case, binaries will try user namespace support and fall back to PRoot if user
4861 namespaces are not supported.
4863 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4864 support for file system virtualization. It achieves that by using the
4865 @code{ptrace} system call on the running program. This approach has the
4866 advantage to work without requiring special kernel support, but it incurs
4867 run-time overhead every time a system call is made.
4870 @cindex entry point, for Docker images
4871 @item --entry-point=@var{command}
4872 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
4873 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
4874 support it. @var{command} must be relative to the profile contained in the
4877 The entry point specifies the command that tools like @code{docker run} or
4878 @code{singularity run} automatically start by default. For example, you can
4882 guix pack -f docker --entry-point=bin/guile guile
4885 The resulting pack can easily be loaded and @code{docker run} with no extra
4886 arguments will spawn @code{bin/guile}:
4889 docker load -i pack.tar.gz
4890 docker run @var{image-id}
4893 @item --expression=@var{expr}
4894 @itemx -e @var{expr}
4895 Consider the package @var{expr} evaluates to.
4897 This has the same purpose as the same-named option in @command{guix
4898 build} (@pxref{Additional Build Options, @code{--expression} in
4899 @command{guix build}}).
4901 @item --manifest=@var{file}
4902 @itemx -m @var{file}
4903 Use the packages contained in the manifest object returned by the Scheme
4906 This has a similar purpose as the same-named option in @command{guix
4907 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4908 same manifest files. It allows you to define a collection of packages
4909 once and use it both for creating profiles and for creating archives
4910 for use on machines that do not have Guix installed. Note that you can
4911 specify @emph{either} a manifest file @emph{or} a list of packages,
4914 @item --system=@var{system}
4915 @itemx -s @var{system}
4916 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4917 the system type of the build host.
4919 @item --target=@var{triplet}
4920 @cindex cross-compilation
4921 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4922 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4923 configuration triplets,, autoconf, Autoconf}).
4925 @item --compression=@var{tool}
4926 @itemx -C @var{tool}
4927 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4928 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4930 @item --symlink=@var{spec}
4931 @itemx -S @var{spec}
4932 Add the symlinks specified by @var{spec} to the pack. This option can
4933 appear several times.
4935 @var{spec} has the form @code{@var{source}=@var{target}}, where
4936 @var{source} is the symlink that will be created and @var{target} is the
4939 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4940 symlink pointing to the @file{bin} sub-directory of the profile.
4942 @item --save-provenance
4943 Save provenance information for the packages passed on the command line.
4944 Provenance information includes the URL and commit of the channels in use
4947 Provenance information is saved in the
4948 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4949 usual package metadata---the name and version of each package, their
4950 propagated inputs, and so on. It is useful information to the recipient of
4951 the pack, who then knows how the pack was (supposedly) obtained.
4953 This option is not enabled by default because, like timestamps, provenance
4954 information contributes nothing to the build process. In other words, there
4955 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4956 Recording such ``silent'' metadata in the output thus potentially breaks the
4957 source-to-binary bitwise reproducibility property.
4959 @item --root=@var{file}
4960 @itemx -r @var{file}
4961 @cindex garbage collector root, for packs
4962 Make @var{file} a symlink to the resulting pack, and register it as a garbage
4965 @item --localstatedir
4966 @itemx --profile-name=@var{name}
4967 Include the ``local state directory'', @file{/var/guix}, in the resulting
4968 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4969 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4970 @file{~root/.guix-profile}.
4972 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4973 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
4974 the pack means that the store is ``complete'' and manageable by Guix;
4975 not providing it pack means that the store is ``dead'': items cannot be
4976 added to it or removed from it after extraction of the pack.
4978 One use case for this is the Guix self-contained binary tarball
4979 (@pxref{Binary Installation}).
4982 Use the bootstrap binaries to build the pack. This option is only
4983 useful to Guix developers.
4986 In addition, @command{guix pack} supports all the common build options
4987 (@pxref{Common Build Options}) and all the package transformation
4988 options (@pxref{Package Transformation Options}).
4991 @c *********************************************************************
4992 @node Programming Interface
4993 @chapter Programming Interface
4995 GNU Guix provides several Scheme programming interfaces (APIs) to
4996 define, build, and query packages. The first interface allows users to
4997 write high-level package definitions. These definitions refer to
4998 familiar packaging concepts, such as the name and version of a package,
4999 its build system, and its dependencies. These definitions can then be
5000 turned into concrete build actions.
5002 Build actions are performed by the Guix daemon, on behalf of users. In a
5003 standard setup, the daemon has write access to the store---the
5004 @file{/gnu/store} directory---whereas users do not. The recommended
5005 setup also has the daemon perform builds in chroots, under a specific
5006 build users, to minimize interference with the rest of the system.
5009 Lower-level APIs are available to interact with the daemon and the
5010 store. To instruct the daemon to perform a build action, users actually
5011 provide it with a @dfn{derivation}. A derivation is a low-level
5012 representation of the build actions to be taken, and the environment in
5013 which they should occur---derivations are to package definitions what
5014 assembly is to C programs. The term ``derivation'' comes from the fact
5015 that build results @emph{derive} from them.
5017 This chapter describes all these APIs in turn, starting from high-level
5018 package definitions.
5021 * Package Modules:: Packages from the programmer's viewpoint.
5022 * Defining Packages:: Defining new packages.
5023 * Build Systems:: Specifying how packages are built.
5024 * The Store:: Manipulating the package store.
5025 * Derivations:: Low-level interface to package derivations.
5026 * The Store Monad:: Purely functional interface to the store.
5027 * G-Expressions:: Manipulating build expressions.
5028 * Invoking guix repl:: Fiddling with Guix interactively.
5031 @node Package Modules
5032 @section Package Modules
5034 From a programming viewpoint, the package definitions of the
5035 GNU distribution are provided by Guile modules in the @code{(gnu packages
5036 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5037 packages @dots{})} module name space are not necessarily ``GNU
5038 packages''. This module naming scheme follows the usual Guile module
5039 naming convention: @code{gnu} means that these modules are distributed
5040 as part of the GNU system, and @code{packages} identifies modules that
5041 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5042 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5043 module exports a variable named @code{emacs}, which is bound to a
5044 @code{<package>} object (@pxref{Defining Packages}).
5046 The @code{(gnu packages @dots{})} module name space is
5047 automatically scanned for packages by the command-line tools. For
5048 instance, when running @code{guix install emacs}, all the @code{(gnu
5049 packages @dots{})} modules are scanned until one that exports a package
5050 object whose name is @code{emacs} is found. This package search
5051 facility is implemented in the @code{(gnu packages)} module.
5053 @cindex customization, of packages
5054 @cindex package module search path
5055 Users can store package definitions in modules with different
5056 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5057 name and module name must match. For instance, the @code{(my-packages
5058 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5059 relative to the load path specified with @option{--load-path} or
5060 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5061 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5062 these package definitions visible to the user interfaces:
5066 By adding the directory containing your package modules to the search path
5067 with the @code{-L} flag of @command{guix package} and other commands
5068 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5069 environment variable described below.
5072 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5073 pulls from it. A channel is essentially a Git repository containing package
5074 modules. @xref{Channels}, for more information on how to define and use
5078 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5080 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5081 This is a colon-separated list of directories to search for additional
5082 package modules. Directories listed in this variable take precedence
5083 over the own modules of the distribution.
5086 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5087 each package is built based solely on other packages in the
5088 distribution. The root of this dependency graph is a small set of
5089 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5090 bootstrap)} module. For more information on bootstrapping,
5091 @pxref{Bootstrapping}.
5093 @node Defining Packages
5094 @section Defining Packages
5096 The high-level interface to package definitions is implemented in the
5097 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5098 example, the package definition, or @dfn{recipe}, for the GNU Hello
5099 package looks like this:
5102 (define-module (gnu packages hello)
5103 #:use-module (guix packages)
5104 #:use-module (guix download)
5105 #:use-module (guix build-system gnu)
5106 #:use-module (guix licenses)
5107 #:use-module (gnu packages gawk))
5109 (define-public hello
5115 (uri (string-append "mirror://gnu/hello/hello-" version
5119 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5120 (build-system gnu-build-system)
5121 (arguments '(#:configure-flags '("--enable-silent-rules")))
5122 (inputs `(("gawk" ,gawk)))
5123 (synopsis "Hello, GNU world: An example GNU package")
5124 (description "Guess what GNU Hello prints!")
5125 (home-page "https://www.gnu.org/software/hello/")
5130 Without being a Scheme expert, the reader may have guessed the meaning
5131 of the various fields here. This expression binds the variable
5132 @code{hello} to a @code{<package>} object, which is essentially a record
5133 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5134 This package object can be inspected using procedures found in the
5135 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5136 returns---surprise!---@code{"hello"}.
5138 With luck, you may be able to import part or all of the definition of
5139 the package you are interested in from another repository, using the
5140 @code{guix import} command (@pxref{Invoking guix import}).
5142 In the example above, @var{hello} is defined in a module of its own,
5143 @code{(gnu packages hello)}. Technically, this is not strictly
5144 necessary, but it is convenient to do so: all the packages defined in
5145 modules under @code{(gnu packages @dots{})} are automatically known to
5146 the command-line tools (@pxref{Package Modules}).
5148 There are a few points worth noting in the above package definition:
5152 The @code{source} field of the package is an @code{<origin>} object
5153 (@pxref{origin Reference}, for the complete reference).
5154 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5155 meaning that the source is a file to be downloaded over FTP or HTTP.
5157 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5158 the GNU mirrors defined in @code{(guix download)}.
5160 The @code{sha256} field specifies the expected SHA256 hash of the file
5161 being downloaded. It is mandatory, and allows Guix to check the
5162 integrity of the file. The @code{(base32 @dots{})} form introduces the
5163 base32 representation of the hash. You can obtain this information with
5164 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5165 hash} (@pxref{Invoking guix hash}).
5168 When needed, the @code{origin} form can also have a @code{patches} field
5169 listing patches to be applied, and a @code{snippet} field giving a
5170 Scheme expression to modify the source code.
5173 @cindex GNU Build System
5174 The @code{build-system} field specifies the procedure to build the
5175 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5176 represents the familiar GNU Build System, where packages may be
5177 configured, built, and installed with the usual @code{./configure &&
5178 make && make check && make install} command sequence.
5181 The @code{arguments} field specifies options for the build system
5182 (@pxref{Build Systems}). Here it is interpreted by
5183 @var{gnu-build-system} as a request run @file{configure} with the
5184 @code{--enable-silent-rules} flag.
5190 What about these quote (@code{'}) characters? They are Scheme syntax to
5191 introduce a literal list; @code{'} is synonymous with @code{quote}.
5192 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5193 for details. Here the value of the @code{arguments} field is a list of
5194 arguments passed to the build system down the road, as with @code{apply}
5195 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5198 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5199 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5200 @code{#:configure-flags} is a keyword used to pass a keyword argument
5201 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5205 The @code{inputs} field specifies inputs to the build process---i.e.,
5206 build-time or run-time dependencies of the package. Here, we define an
5207 input called @code{"gawk"} whose value is that of the @var{gawk}
5208 variable; @var{gawk} is itself bound to a @code{<package>} object.
5210 @cindex backquote (quasiquote)
5213 @cindex comma (unquote)
5217 @findex unquote-splicing
5218 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5219 us to introduce a literal list in the @code{inputs} field, while
5220 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5221 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5224 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5225 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5226 of ensuring that they are present (@pxref{Build Systems}).
5228 However, any other dependencies need to be specified in the
5229 @code{inputs} field. Any dependency not specified here will simply be
5230 unavailable to the build process, possibly leading to a build failure.
5233 @xref{package Reference}, for a full description of possible fields.
5235 Once a package definition is in place, the
5236 package may actually be built using the @code{guix build} command-line
5237 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5238 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5239 package definition using the @command{guix edit} command
5240 (@pxref{Invoking guix edit}).
5241 @xref{Packaging Guidelines}, for
5242 more information on how to test package definitions, and
5243 @ref{Invoking guix lint}, for information on how to check a definition
5244 for style conformance.
5245 @vindex GUIX_PACKAGE_PATH
5246 Lastly, @pxref{Channels}, for information
5247 on how to extend the distribution by adding your own package definitions
5250 Finally, updating the package definition to a new upstream version
5251 can be partly automated by the @command{guix refresh} command
5252 (@pxref{Invoking guix refresh}).
5254 Behind the scenes, a derivation corresponding to the @code{<package>}
5255 object is first computed by the @code{package-derivation} procedure.
5256 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5257 The build actions it prescribes may then be realized by using the
5258 @code{build-derivations} procedure (@pxref{The Store}).
5260 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5261 Return the @code{<derivation>} object of @var{package} for @var{system}
5262 (@pxref{Derivations}).
5264 @var{package} must be a valid @code{<package>} object, and @var{system}
5265 must be a string denoting the target system type---e.g.,
5266 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5267 must be a connection to the daemon, which operates on the store
5268 (@pxref{The Store}).
5272 @cindex cross-compilation
5273 Similarly, it is possible to compute a derivation that cross-builds a
5274 package for some other system:
5276 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5277 @var{package} @var{target} [@var{system}]
5278 Return the @code{<derivation>} object of @var{package} cross-built from
5279 @var{system} to @var{target}.
5281 @var{target} must be a valid GNU triplet denoting the target hardware
5282 and operating system, such as @code{"mips64el-linux-gnu"}
5283 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5286 @cindex package transformations
5287 @cindex input rewriting
5288 @cindex dependency tree rewriting
5289 Packages can be manipulated in arbitrary ways. An example of a useful
5290 transformation is @dfn{input rewriting}, whereby the dependency tree of
5291 a package is rewritten by replacing specific inputs by others:
5293 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5294 [@var{rewrite-name}]
5295 Return a procedure that, when passed a package, replaces its direct and
5296 indirect dependencies (but not its implicit inputs) according to
5297 @var{replacements}. @var{replacements} is a list of package pairs; the
5298 first element of each pair is the package to replace, and the second one
5301 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5302 the name of a package and returns its new name after rewrite.
5306 Consider this example:
5309 (define libressl-instead-of-openssl
5310 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5312 (package-input-rewriting `((,openssl . ,libressl))))
5314 (define git-with-libressl
5315 (libressl-instead-of-openssl git))
5319 Here we first define a rewriting procedure that replaces @var{openssl}
5320 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5321 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5322 This is exactly what the @option{--with-input} command-line option does
5323 (@pxref{Package Transformation Options, @option{--with-input}}).
5325 The following variant of @code{package-input-rewriting} can match packages to
5326 be replaced by name rather than by identity.
5328 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5329 Return a procedure that, given a package, applies the given @var{replacements} to
5330 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5331 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5332 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5333 replacement for that package.
5336 The example above could be rewritten this way:
5339 (define libressl-instead-of-openssl
5340 ;; Replace all the packages called "openssl" with LibreSSL.
5341 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5344 The key difference here is that, this time, packages are matched by spec and
5345 not by identity. In other words, any package in the graph that is called
5346 @code{openssl} will be replaced.
5348 A more generic procedure to rewrite a package dependency graph is
5349 @code{package-mapping}: it supports arbitrary changes to nodes in the
5352 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5353 Return a procedure that, given a package, applies @var{proc} to all the packages
5354 depended on and returns the resulting package. The procedure stops recursion
5355 when @var{cut?} returns true for a given package.
5359 * package Reference:: The package data type.
5360 * origin Reference:: The origin data type.
5364 @node package Reference
5365 @subsection @code{package} Reference
5367 This section summarizes all the options available in @code{package}
5368 declarations (@pxref{Defining Packages}).
5370 @deftp {Data Type} package
5371 This is the data type representing a package recipe.
5375 The name of the package, as a string.
5377 @item @code{version}
5378 The version of the package, as a string.
5381 An object telling how the source code for the package should be
5382 acquired. Most of the time, this is an @code{origin} object, which
5383 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5384 can also be any other ``file-like'' object such as a @code{local-file},
5385 which denotes a file from the local file system (@pxref{G-Expressions,
5386 @code{local-file}}).
5388 @item @code{build-system}
5389 The build system that should be used to build the package (@pxref{Build
5392 @item @code{arguments} (default: @code{'()})
5393 The arguments that should be passed to the build system. This is a
5394 list, typically containing sequential keyword-value pairs.
5396 @item @code{inputs} (default: @code{'()})
5397 @itemx @code{native-inputs} (default: @code{'()})
5398 @itemx @code{propagated-inputs} (default: @code{'()})
5399 @cindex inputs, of packages
5400 These fields list dependencies of the package. Each one is a list of
5401 tuples, where each tuple has a label for the input (a string) as its
5402 first element, a package, origin, or derivation as its second element,
5403 and optionally the name of the output thereof that should be used, which
5404 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5405 more on package outputs). For example, the list below specifies three
5409 `(("libffi" ,libffi)
5410 ("libunistring" ,libunistring)
5411 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5414 @cindex cross compilation, package dependencies
5415 The distinction between @code{native-inputs} and @code{inputs} is
5416 necessary when considering cross-compilation. When cross-compiling,
5417 dependencies listed in @code{inputs} are built for the @emph{target}
5418 architecture; conversely, dependencies listed in @code{native-inputs}
5419 are built for the architecture of the @emph{build} machine.
5421 @code{native-inputs} is typically used to list tools needed at
5422 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5423 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5424 this area (@pxref{Invoking guix lint}).
5426 @anchor{package-propagated-inputs}
5427 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5428 specified packages will be automatically installed alongside the package
5429 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5430 package}}, for information on how @command{guix package} deals with
5433 For example this is necessary when a C/C++ library needs headers of
5434 another library to compile, or when a pkg-config file refers to another
5435 one @i{via} its @code{Requires} field.
5437 Another example where @code{propagated-inputs} is useful is for languages
5438 that lack a facility to record the run-time search path akin to the
5439 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5440 more. To ensure that libraries written in those languages can find
5441 library code they depend on at run time, run-time dependencies must be
5442 listed in @code{propagated-inputs} rather than @code{inputs}.
5444 @item @code{outputs} (default: @code{'("out")})
5445 The list of output names of the package. @xref{Packages with Multiple
5446 Outputs}, for typical uses of additional outputs.
5448 @item @code{native-search-paths} (default: @code{'()})
5449 @itemx @code{search-paths} (default: @code{'()})
5450 A list of @code{search-path-specification} objects describing
5451 search-path environment variables honored by the package.
5453 @item @code{replacement} (default: @code{#f})
5454 This must be either @code{#f} or a package object that will be used as a
5455 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5458 @item @code{synopsis}
5459 A one-line description of the package.
5461 @item @code{description}
5462 A more elaborate description of the package.
5464 @item @code{license}
5465 @cindex license, of packages
5466 The license of the package; a value from @code{(guix licenses)},
5467 or a list of such values.
5469 @item @code{home-page}
5470 The URL to the home-page of the package, as a string.
5472 @item @code{supported-systems} (default: @var{%supported-systems})
5473 The list of systems supported by the package, as strings of the form
5474 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5476 @item @code{maintainers} (default: @code{'()})
5477 The list of maintainers of the package, as @code{maintainer} objects.
5479 @item @code{location} (default: source location of the @code{package} form)
5480 The source location of the package. It is useful to override this when
5481 inheriting from another package, in which case this field is not
5482 automatically corrected.
5486 @deffn {Scheme Syntax} this-package
5487 When used in the @emph{lexical scope} of a package field definition, this
5488 identifier resolves to the package being defined.
5490 The example below shows how to add a package as a native input of itself when
5498 ;; When cross-compiled, Guile, for example, depends on
5499 ;; a native version of itself. Add it here.
5500 (native-inputs (if (%current-target-system)
5501 `(("self" ,this-package))
5505 It is an error to refer to @code{this-package} outside a package definition.
5508 @node origin Reference
5509 @subsection @code{origin} Reference
5511 This section summarizes all the options available in @code{origin}
5512 declarations (@pxref{Defining Packages}).
5514 @deftp {Data Type} origin
5515 This is the data type representing a source code origin.
5519 An object containing the URI of the source. The object type depends on
5520 the @code{method} (see below). For example, when using the
5521 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5522 values are: a URL represented as a string, or a list thereof.
5525 A procedure that handles the URI.
5530 @item @var{url-fetch} from @code{(guix download)}
5531 download a file from the HTTP, HTTPS, or FTP URL specified in the
5535 @item @var{git-fetch} from @code{(guix git-download)}
5536 clone the Git version control repository, and check out the revision
5537 specified in the @code{uri} field as a @code{git-reference} object; a
5538 @code{git-reference} looks like this:
5542 (url "git://git.debian.org/git/pkg-shadow/shadow")
5543 (commit "v4.1.5.1"))
5548 A bytevector containing the SHA-256 hash of the source. Typically the
5549 @code{base32} form is used here to generate the bytevector from a
5552 You can obtain this information using @code{guix download}
5553 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5556 @item @code{file-name} (default: @code{#f})
5557 The file name under which the source code should be saved. When this is
5558 @code{#f}, a sensible default value will be used in most cases. In case
5559 the source is fetched from a URL, the file name from the URL will be
5560 used. For version control checkouts, it is recommended to provide the
5561 file name explicitly because the default is not very descriptive.
5563 @item @code{patches} (default: @code{'()})
5564 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5565 file-like objects}) pointing to patches to be applied to the source.
5567 This list of patches must be unconditional. In particular, it cannot
5568 depend on the value of @code{%current-system} or
5569 @code{%current-target-system}.
5571 @item @code{snippet} (default: @code{#f})
5572 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5573 in the source directory. This is a convenient way to modify the source,
5574 sometimes more convenient than a patch.
5576 @item @code{patch-flags} (default: @code{'("-p1")})
5577 A list of command-line flags that should be passed to the @code{patch}
5580 @item @code{patch-inputs} (default: @code{#f})
5581 Input packages or derivations to the patching process. When this is
5582 @code{#f}, the usual set of inputs necessary for patching are provided,
5583 such as GNU@tie{}Patch.
5585 @item @code{modules} (default: @code{'()})
5586 A list of Guile modules that should be loaded during the patching
5587 process and while running the code in the @code{snippet} field.
5589 @item @code{patch-guile} (default: @code{#f})
5590 The Guile package that should be used in the patching process. When
5591 this is @code{#f}, a sensible default is used.
5597 @section Build Systems
5599 @cindex build system
5600 Each package definition specifies a @dfn{build system} and arguments for
5601 that build system (@pxref{Defining Packages}). This @code{build-system}
5602 field represents the build procedure of the package, as well as implicit
5603 dependencies of that build procedure.
5605 Build systems are @code{<build-system>} objects. The interface to
5606 create and manipulate them is provided by the @code{(guix build-system)}
5607 module, and actual build systems are exported by specific modules.
5609 @cindex bag (low-level package representation)
5610 Under the hood, build systems first compile package objects to
5611 @dfn{bags}. A @dfn{bag} is like a package, but with less
5612 ornamentation---in other words, a bag is a lower-level representation of
5613 a package, which includes all the inputs of that package, including some
5614 that were implicitly added by the build system. This intermediate
5615 representation is then compiled to a derivation (@pxref{Derivations}).
5617 Build systems accept an optional list of @dfn{arguments}. In package
5618 definitions, these are passed @i{via} the @code{arguments} field
5619 (@pxref{Defining Packages}). They are typically keyword arguments
5620 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5621 Guile Reference Manual}). The value of these arguments is usually
5622 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5623 by the daemon (@pxref{Derivations}).
5625 The main build system is @var{gnu-build-system}, which implements the
5626 standard build procedure for GNU and many other packages. It
5627 is provided by the @code{(guix build-system gnu)} module.
5629 @defvr {Scheme Variable} gnu-build-system
5630 @var{gnu-build-system} represents the GNU Build System, and variants
5631 thereof (@pxref{Configuration, configuration and makefile conventions,,
5632 standards, GNU Coding Standards}).
5634 @cindex build phases
5635 In a nutshell, packages using it are configured, built, and installed with
5636 the usual @code{./configure && make && make check && make install}
5637 command sequence. In practice, a few additional steps are often needed.
5638 All these steps are split up in separate @dfn{phases},
5639 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5640 modules for more details about the build phases.}:
5644 Unpack the source tarball, and change the current directory to the
5645 extracted source tree. If the source is actually a directory, copy it
5646 to the build tree, and enter that directory.
5648 @item patch-source-shebangs
5649 Patch shebangs encountered in source files so they refer to the right
5650 store file names. For instance, this changes @code{#!/bin/sh} to
5651 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5654 Run the @file{configure} script with a number of default options, such
5655 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5656 by the @code{#:configure-flags} argument.
5659 Run @code{make} with the list of flags specified with
5660 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5661 (the default), build with @code{make -j}.
5664 Run @code{make check}, or some other target specified with
5665 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5666 @code{#:parallel-tests?} argument is true (the default), run @code{make
5670 Run @code{make install} with the flags listed in @code{#:make-flags}.
5672 @item patch-shebangs
5673 Patch shebangs on the installed executable files.
5676 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5677 is false), copying them to the @code{debug} output when available
5678 (@pxref{Installing Debugging Files}).
5681 @vindex %standard-phases
5682 The build-side module @code{(guix build gnu-build-system)} defines
5683 @var{%standard-phases} as the default list of build phases.
5684 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5685 procedure implements the actual phase.
5687 The list of phases used for a particular package can be changed with the
5688 @code{#:phases} parameter. For instance, passing:
5691 #:phases (modify-phases %standard-phases (delete 'configure))
5694 means that all the phases described above will be used, except the
5695 @code{configure} phase.
5697 In addition, this build system ensures that the ``standard'' environment
5698 for GNU packages is available. This includes tools such as GCC, libc,
5699 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5700 build-system gnu)} module for a complete list). We call these the
5701 @dfn{implicit inputs} of a package, because package definitions do not
5702 have to mention them.
5705 Other @code{<build-system>} objects are defined to support other
5706 conventions and tools used by free software packages. They inherit most
5707 of @var{gnu-build-system}, and differ mainly in the set of inputs
5708 implicitly added to the build process, and in the list of phases
5709 executed. Some of these build systems are listed below.
5711 @defvr {Scheme Variable} ant-build-system
5712 This variable is exported by @code{(guix build-system ant)}. It
5713 implements the build procedure for Java packages that can be built with
5714 @url{https://ant.apache.org/, Ant build tool}.
5716 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5717 provided by the @code{icedtea} package to the set of inputs. Different
5718 packages can be specified with the @code{#:ant} and @code{#:jdk}
5719 parameters, respectively.
5721 When the original package does not provide a suitable Ant build file,
5722 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5723 build file @file{build.xml} with tasks to build the specified jar
5724 archive. In this case the parameter @code{#:source-dir} can be used to
5725 specify the source sub-directory, defaulting to ``src''.
5727 The @code{#:main-class} parameter can be used with the minimal ant
5728 buildfile to specify the main class of the resulting jar. This makes the
5729 jar file executable. The @code{#:test-include} parameter can be used to
5730 specify the list of junit tests to run. It defaults to
5731 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5732 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5733 because abstract classes cannot be run as tests.
5735 The parameter @code{#:build-target} can be used to specify the Ant task
5736 that should be run during the @code{build} phase. By default the
5737 ``jar'' task will be run.
5741 @defvr {Scheme Variable} android-ndk-build-system
5742 @cindex Android distribution
5743 @cindex Android NDK build system
5744 This variable is exported by @code{(guix build-system android-ndk)}. It
5745 implements a build procedure for Android NDK (native development kit)
5746 packages using a Guix-specific build process.
5748 The build system assumes that packages install their public interface
5749 (header) files to the subdirectory "include" of the "out" output and
5750 their libraries to the subdirectory "lib" of the "out" output.
5752 It's also assumed that the union of all the dependencies of a package
5753 has no conflicting files.
5755 For the time being, cross-compilation is not supported - so right now
5756 the libraries and header files are assumed to be host tools.
5760 @defvr {Scheme Variable} asdf-build-system/source
5761 @defvrx {Scheme Variable} asdf-build-system/sbcl
5762 @defvrx {Scheme Variable} asdf-build-system/ecl
5764 These variables, exported by @code{(guix build-system asdf)}, implement
5765 build procedures for Common Lisp packages using
5766 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5767 definition facility for Common Lisp programs and libraries.
5769 The @code{asdf-build-system/source} system installs the packages in
5770 source form, and can be loaded using any common lisp implementation, via
5771 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5772 systems in the format which a particular implementation understands.
5773 These build systems can also be used to produce executable programs, or
5774 lisp images which contain a set of packages pre-loaded.
5776 The build system uses naming conventions. For binary packages, the
5777 package name should be prefixed with the lisp implementation, such as
5778 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5780 Additionally, the corresponding source package should be labeled using
5781 the same convention as python packages (see @ref{Python Modules}), using
5782 the @code{cl-} prefix.
5784 For binary packages, each system should be defined as a Guix package.
5785 If one package @code{origin} contains several systems, package variants
5786 can be created in order to build all the systems. Source packages,
5787 which use @code{asdf-build-system/source}, may contain several systems.
5789 In order to create executable programs and images, the build-side
5790 procedures @code{build-program} and @code{build-image} can be used.
5791 They should be called in a build phase after the @code{create-symlinks}
5792 phase, so that the system which was just built can be used within the
5793 resulting image. @code{build-program} requires a list of Common Lisp
5794 expressions to be passed as the @code{#:entry-program} argument.
5796 If the system is not defined within its own @code{.asd} file of the same
5797 name, then the @code{#:asd-file} parameter should be used to specify
5798 which file the system is defined in. Furthermore, if the package
5799 defines a system for its tests in a separate file, it will be loaded
5800 before the tests are run if it is specified by the
5801 @code{#:test-asd-file} parameter. If it is not set, the files
5802 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5803 and @code{test.asd} will be tried if they exist.
5805 If for some reason the package must be named in a different way than the
5806 naming conventions suggest, the @code{#:asd-system-name} parameter can
5807 be used to specify the name of the system.
5811 @defvr {Scheme Variable} cargo-build-system
5812 @cindex Rust programming language
5813 @cindex Cargo (Rust build system)
5814 This variable is exported by @code{(guix build-system cargo)}. It
5815 supports builds of packages using Cargo, the build tool of the
5816 @uref{https://www.rust-lang.org, Rust programming language}.
5818 It adds @code{rustc} and @code{cargo} to the set of inputs.
5819 A different Rust package can be specified with the @code{#:rust} parameter.
5821 Regular cargo dependencies should be added to the package definition via the
5822 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
5823 spec can be a package or a source definition. Note that the spec must
5824 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
5825 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
5826 should be added to the package definition via the
5827 @code{#:cargo-development-inputs} parameter.
5829 In its @code{configure} phase, this build system will make any source inputs
5830 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
5831 parameters available to cargo. The @code{install} phase installs any crate
5832 the binaries if they are defined by the crate.
5835 @cindex Clojure (programming language)
5836 @cindex simple Clojure build system
5837 @defvr {Scheme Variable} clojure-build-system
5838 This variable is exported by @code{(guix build-system clojure)}. It implements
5839 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5840 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5843 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5844 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5845 @code{#:zip} parameters, respectively.
5847 A list of source directories, test directories and jar names can be specified
5848 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5849 parameters, respectively. Compile directory and main class can be specified
5850 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5851 Other parameters are documented below.
5853 This build system is an extension of @var{ant-build-system}, but with the
5854 following phases changed:
5859 This phase calls @code{compile} in Clojure to compile source files and runs
5860 @command{jar} to create jars from both source files and compiled files
5861 according to the include list and exclude list specified in
5862 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5863 has priority over the include list. These lists consist of symbols
5864 representing Clojure libraries or the special keyword @code{#:all} representing
5865 all Clojure libraries found under the source directories. The parameter
5866 @code{#:omit-source?} decides if source should be included into the jars.
5869 This phase runs tests according to the include list and exclude list specified
5870 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5871 meanings are analogous to that of @code{#:aot-include} and
5872 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5873 stands for all Clojure libraries found under the test directories. The
5874 parameter @code{#:tests?} decides if tests should be run.
5877 This phase installs all jars built previously.
5880 Apart from the above, this build system also contains an additional phase:
5885 This phase installs all top-level files with base name matching
5886 @var{%doc-regex}. A different regex can be specified with the
5887 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5888 directories specified in @code{#:doc-dirs} are installed as well.
5892 @defvr {Scheme Variable} cmake-build-system
5893 This variable is exported by @code{(guix build-system cmake)}. It
5894 implements the build procedure for packages using the
5895 @url{https://www.cmake.org, CMake build tool}.
5897 It automatically adds the @code{cmake} package to the set of inputs.
5898 Which package is used can be specified with the @code{#:cmake}
5901 The @code{#:configure-flags} parameter is taken as a list of flags
5902 passed to the @command{cmake} command. The @code{#:build-type}
5903 parameter specifies in abstract terms the flags passed to the compiler;
5904 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5905 debugging information''), which roughly means that code is compiled with
5906 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5909 @defvr {Scheme Variable} dune-build-system
5910 This variable is exported by @code{(guix build-system dune)}. It
5911 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5912 tool for the OCaml programming language. It is implemented as an extension
5913 of the @code{ocaml-build-system} which is described below. As such, the
5914 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5917 It automatically adds the @code{dune} package to the set of inputs.
5918 Which package is used can be specified with the @code{#:dune}
5921 There is no @code{configure} phase because dune packages typically don't
5922 need to be configured. The @code{#:build-flags} parameter is taken as a
5923 list of flags passed to the @code{dune} command during the build.
5925 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5926 command instead of the more recent @code{dune} command while building
5927 a package. Its default value is @code{#f}.
5929 The @code{#:package} parameter can be passed to specify a package name, which
5930 is useful when a package contains multiple packages and you want to build
5931 only one of them. This is equivalent to passing the @code{-p} argument to
5935 @defvr {Scheme Variable} go-build-system
5936 This variable is exported by @code{(guix build-system go)}. It
5937 implements a build procedure for Go packages using the standard
5938 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5939 Go build mechanisms}.
5941 The user is expected to provide a value for the key @code{#:import-path}
5942 and, in some cases, @code{#:unpack-path}. The
5943 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5944 corresponds to the file system path expected by the package's build
5945 scripts and any referring packages, and provides a unique way to
5946 refer to a Go package. It is typically based on a combination of the
5947 package source code's remote URI and file system hierarchy structure. In
5948 some cases, you will need to unpack the package's source code to a
5949 different directory structure than the one indicated by the import path,
5950 and @code{#:unpack-path} should be used in such cases.
5952 Packages that provide Go libraries should install their source code into
5953 the built output. The key @code{#:install-source?}, which defaults to
5954 @code{#t}, controls whether or not the source code is installed. It can
5955 be set to @code{#f} for packages that only provide executable files.
5958 @defvr {Scheme Variable} glib-or-gtk-build-system
5959 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5960 is intended for use with packages making use of GLib or GTK+.
5962 This build system adds the following two phases to the ones defined by
5963 @var{gnu-build-system}:
5966 @item glib-or-gtk-wrap
5967 The phase @code{glib-or-gtk-wrap} ensures that programs in
5968 @file{bin/} are able to find GLib ``schemas'' and
5969 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5970 modules}. This is achieved by wrapping the programs in launch scripts
5971 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
5972 environment variables.
5974 It is possible to exclude specific package outputs from that wrapping
5975 process by listing their names in the
5976 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
5977 when an output is known not to contain any GLib or GTK+ binaries, and
5978 where wrapping would gratuitously add a dependency of that output on
5981 @item glib-or-gtk-compile-schemas
5982 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
5983 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
5984 GSettings schemas} of GLib are compiled. Compilation is performed by the
5985 @command{glib-compile-schemas} program. It is provided by the package
5986 @code{glib:bin} which is automatically imported by the build system.
5987 The @code{glib} package providing @command{glib-compile-schemas} can be
5988 specified with the @code{#:glib} parameter.
5991 Both phases are executed after the @code{install} phase.
5994 @defvr {Scheme Variable} guile-build-system
5995 This build system is for Guile packages that consist exclusively of Scheme
5996 code and that are so lean that they don't even have a makefile, let alone a
5997 @file{configure} script. It compiles Scheme code using @command{guild
5998 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
5999 installs the @file{.scm} and @file{.go} files in the right place. It also
6000 installs documentation.
6002 This build system supports cross-compilation by using the @code{--target}
6003 option of @command{guild compile}.
6005 Packages built with @code{guile-build-system} must provide a Guile package in
6006 their @code{native-inputs} field.
6009 @defvr {Scheme Variable} minify-build-system
6010 This variable is exported by @code{(guix build-system minify)}. It
6011 implements a minification procedure for simple JavaScript packages.
6013 It adds @code{uglify-js} to the set of inputs and uses it to compress
6014 all JavaScript files in the @file{src} directory. A different minifier
6015 package can be specified with the @code{#:uglify-js} parameter, but it
6016 is expected that the package writes the minified code to the standard
6019 When the input JavaScript files are not all located in the @file{src}
6020 directory, the parameter @code{#:javascript-files} can be used to
6021 specify a list of file names to feed to the minifier.
6024 @defvr {Scheme Variable} ocaml-build-system
6025 This variable is exported by @code{(guix build-system ocaml)}. It implements
6026 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6027 of choosing the correct set of commands to run for each package. OCaml
6028 packages can expect many different commands to be run. This build system will
6031 When the package has a @file{setup.ml} file present at the top-level, it will
6032 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6033 @code{ocaml setup.ml -install}. The build system will assume that this file
6034 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6035 care of setting the prefix and enabling tests if they are not disabled. You
6036 can pass configure and build flags with the @code{#:configure-flags} and
6037 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6038 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6039 bypass this system in the build and install phases.
6041 When the package has a @file{configure} file, it is assumed that it is a
6042 hand-made configure script that requires a different argument format than
6043 in the @code{gnu-build-system}. You can add more flags with the
6044 @code{#:configure-flags} key.
6046 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6047 @code{#t}), it will be used and more flags can be passed to the build and
6048 install phases with the @code{#:make-flags} key.
6050 Finally, some packages do not have these files and use a somewhat standard
6051 location for its build system. In that case, the build system will run
6052 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6053 providing the path to the required findlib module. Additional flags can
6054 be passed via the @code{#:build-flags} key. Install is taken care of by
6055 @command{opam-installer}. In this case, the @code{opam} package must
6056 be added to the @code{native-inputs} field of the package definition.
6058 Note that most OCaml packages assume they will be installed in the same
6059 directory as OCaml, which is not what we want in guix. In particular, they
6060 will install @file{.so} files in their module's directory, which is usually
6061 fine because it is in the OCaml compiler directory. In guix though, these
6062 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6063 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6064 @file{.so} libraries should be installed.
6067 @defvr {Scheme Variable} python-build-system
6068 This variable is exported by @code{(guix build-system python)}. It
6069 implements the more or less standard build procedure used by Python
6070 packages, which consists in running @code{python setup.py build} and
6071 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6073 For packages that install stand-alone Python programs under @code{bin/},
6074 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6075 environment variable points to all the Python libraries they depend on.
6077 Which Python package is used to perform the build can be specified with
6078 the @code{#:python} parameter. This is a useful way to force a package
6079 to be built for a specific version of the Python interpreter, which
6080 might be necessary if the package is only compatible with a single
6081 interpreter version.
6083 By default guix calls @code{setup.py} under control of
6084 @code{setuptools}, much like @command{pip} does. Some packages are not
6085 compatible with setuptools (and pip), thus you can disable this by
6086 setting the @code{#:use-setuptools} parameter to @code{#f}.
6089 @defvr {Scheme Variable} perl-build-system
6090 This variable is exported by @code{(guix build-system perl)}. It
6091 implements the standard build procedure for Perl packages, which either
6092 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6093 followed by @code{Build} and @code{Build install}; or in running
6094 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6095 @code{make} and @code{make install}, depending on which of
6096 @code{Build.PL} or @code{Makefile.PL} is present in the package
6097 distribution. Preference is given to the former if both @code{Build.PL}
6098 and @code{Makefile.PL} exist in the package distribution. This
6099 preference can be reversed by specifying @code{#t} for the
6100 @code{#:make-maker?} parameter.
6102 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6103 passes flags specified by the @code{#:make-maker-flags} or
6104 @code{#:module-build-flags} parameter, respectively.
6106 Which Perl package is used can be specified with @code{#:perl}.
6109 @defvr {Scheme Variable} r-build-system
6110 This variable is exported by @code{(guix build-system r)}. It
6111 implements the build procedure used by @uref{https://r-project.org, R}
6112 packages, which essentially is little more than running @code{R CMD
6113 INSTALL --library=/gnu/store/@dots{}} in an environment where
6114 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6115 are run after installation using the R function
6116 @code{tools::testInstalledPackage}.
6119 @defvr {Scheme Variable} rakudo-build-system
6120 This variable is exported by @code{(guix build-system rakudo)}. It
6121 implements the build procedure used by @uref{https://rakudo.org/,
6122 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6123 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6124 installs the binaries, library files and the resources, as well as wrap
6125 the files under the @code{bin/} directory. Tests can be skipped by
6126 passing @code{#f} to the @code{tests?} parameter.
6128 Which rakudo package is used can be specified with @code{rakudo}.
6129 Which perl6-tap-harness package used for the tests can be specified with
6130 @code{#:prove6} or removed by passing @code{#f} to the
6131 @code{with-prove6?} parameter.
6132 Which perl6-zef package used for tests and installing can be specified
6133 with @code{#:zef} or removed by passing @code{#f} to the
6134 @code{with-zef?} parameter.
6137 @defvr {Scheme Variable} texlive-build-system
6138 This variable is exported by @code{(guix build-system texlive)}. It is
6139 used to build TeX packages in batch mode with a specified engine. The
6140 build system sets the @code{TEXINPUTS} variable to find all TeX source
6141 files in the inputs.
6143 By default it runs @code{luatex} on all files ending on @code{ins}. A
6144 different engine and format can be specified with the
6145 @code{#:tex-format} argument. Different build targets can be specified
6146 with the @code{#:build-targets} argument, which expects a list of file
6147 names. The build system adds only @code{texlive-bin} and
6148 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6149 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6150 and @code{#:texlive-latex-base}, respectively.
6152 The @code{#:tex-directory} parameter tells the build system where to
6153 install the built files under the texmf tree.
6156 @defvr {Scheme Variable} ruby-build-system
6157 This variable is exported by @code{(guix build-system ruby)}. It
6158 implements the RubyGems build procedure used by Ruby packages, which
6159 involves running @code{gem build} followed by @code{gem install}.
6161 The @code{source} field of a package that uses this build system
6162 typically references a gem archive, since this is the format that Ruby
6163 developers use when releasing their software. The build system unpacks
6164 the gem archive, potentially patches the source, runs the test suite,
6165 repackages the gem, and installs it. Additionally, directories and
6166 tarballs may be referenced to allow building unreleased gems from Git or
6167 a traditional source release tarball.
6169 Which Ruby package is used can be specified with the @code{#:ruby}
6170 parameter. A list of additional flags to be passed to the @command{gem}
6171 command can be specified with the @code{#:gem-flags} parameter.
6174 @defvr {Scheme Variable} waf-build-system
6175 This variable is exported by @code{(guix build-system waf)}. It
6176 implements a build procedure around the @code{waf} script. The common
6177 phases---@code{configure}, @code{build}, and @code{install}---are
6178 implemented by passing their names as arguments to the @code{waf}
6181 The @code{waf} script is executed by the Python interpreter. Which
6182 Python package is used to run the script can be specified with the
6183 @code{#:python} parameter.
6186 @defvr {Scheme Variable} scons-build-system
6187 This variable is exported by @code{(guix build-system scons)}. It
6188 implements the build procedure used by the SCons software construction
6189 tool. This build system runs @code{scons} to build the package,
6190 @code{scons test} to run tests, and then @code{scons install} to install
6193 Additional flags to be passed to @code{scons} can be specified with the
6194 @code{#:scons-flags} parameter. The version of Python used to run SCons
6195 can be specified by selecting the appropriate SCons package with the
6196 @code{#:scons} parameter.
6199 @defvr {Scheme Variable} haskell-build-system
6200 This variable is exported by @code{(guix build-system haskell)}. It
6201 implements the Cabal build procedure used by Haskell packages, which
6202 involves running @code{runhaskell Setup.hs configure
6203 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6204 Instead of installing the package by running @code{runhaskell Setup.hs
6205 install}, to avoid trying to register libraries in the read-only
6206 compiler store directory, the build system uses @code{runhaskell
6207 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6208 addition, the build system generates the package documentation by
6209 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6210 is passed. Optional Haddock parameters can be passed with the help of
6211 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6212 not found, the build system looks for @code{Setup.lhs} instead.
6214 Which Haskell compiler is used can be specified with the @code{#:haskell}
6215 parameter which defaults to @code{ghc}.
6218 @defvr {Scheme Variable} dub-build-system
6219 This variable is exported by @code{(guix build-system dub)}. It
6220 implements the Dub build procedure used by D packages, which
6221 involves running @code{dub build} and @code{dub run}.
6222 Installation is done by copying the files manually.
6224 Which D compiler is used can be specified with the @code{#:ldc}
6225 parameter which defaults to @code{ldc}.
6228 @defvr {Scheme Variable} emacs-build-system
6229 This variable is exported by @code{(guix build-system emacs)}. It
6230 implements an installation procedure similar to the packaging system
6231 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6233 It first creates the @code{@var{package}-autoloads.el} file, then it
6234 byte compiles all Emacs Lisp files. Differently from the Emacs
6235 packaging system, the Info documentation files are moved to the standard
6236 documentation directory and the @file{dir} file is deleted. Each
6237 package is installed in its own directory under
6238 @file{share/emacs/site-lisp/guix.d}.
6241 @defvr {Scheme Variable} font-build-system
6242 This variable is exported by @code{(guix build-system font)}. It
6243 implements an installation procedure for font packages where upstream
6244 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6245 need to be copied into place. It copies font files to standard
6246 locations in the output directory.
6249 @defvr {Scheme Variable} meson-build-system
6250 This variable is exported by @code{(guix build-system meson)}. It
6251 implements the build procedure for packages that use
6252 @url{https://mesonbuild.com, Meson} as their build system.
6254 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6255 of inputs, and they can be changed with the parameters @code{#:meson}
6256 and @code{#:ninja} if needed. The default Meson is
6257 @code{meson-for-build}, which is special because it doesn't clear the
6258 @code{RUNPATH} of binaries and libraries when they are installed.
6260 This build system is an extension of @var{gnu-build-system}, but with the
6261 following phases changed to some specific for Meson:
6266 The phase runs @code{meson} with the flags specified in
6267 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6268 @code{plain} unless something else is specified in @code{#:build-type}.
6271 The phase runs @code{ninja} to build the package in parallel by default, but
6272 this can be changed with @code{#:parallel-build?}.
6275 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6276 which is @code{"test"} by default.
6279 The phase runs @code{ninja install} and can not be changed.
6282 Apart from that, the build system also adds the following phases:
6287 This phase ensures that all binaries can find the libraries they need.
6288 It searches for required libraries in subdirectories of the package being
6289 built, and adds those to @code{RUNPATH} where needed. It also removes
6290 references to libraries left over from the build phase by
6291 @code{meson-for-build}, such as test dependencies, that aren't actually
6292 required for the program to run.
6294 @item glib-or-gtk-wrap
6295 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6296 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6298 @item glib-or-gtk-compile-schemas
6299 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6300 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6304 @defvr {Scheme Variable} linux-module-build-system
6305 @var{linux-module-build-system} allows building Linux kernel modules.
6307 @cindex build phases
6308 This build system is an extension of @var{gnu-build-system}, but with the
6309 following phases changed:
6314 This phase configures the environment so that the Linux kernel's Makefile
6315 can be used to build the external kernel module.
6318 This phase uses the Linux kernel's Makefile in order to build the external
6322 This phase uses the Linux kernel's Makefile in order to install the external
6326 It is possible and useful to specify the Linux kernel to use for building
6327 the module (in the "arguments" form of a package using the
6328 linux-module-build-system, use the key #:linux to specify it).
6331 Lastly, for packages that do not need anything as sophisticated, a
6332 ``trivial'' build system is provided. It is trivial in the sense that
6333 it provides basically no support: it does not pull any implicit inputs,
6334 and does not have a notion of build phases.
6336 @defvr {Scheme Variable} trivial-build-system
6337 This variable is exported by @code{(guix build-system trivial)}.
6339 This build system requires a @code{#:builder} argument. This argument
6340 must be a Scheme expression that builds the package output(s)---as
6341 with @code{build-expression->derivation} (@pxref{Derivations,
6342 @code{build-expression->derivation}}).
6352 Conceptually, the @dfn{store} is the place where derivations that have
6353 been built successfully are stored---by default, @file{/gnu/store}.
6354 Sub-directories in the store are referred to as @dfn{store items} or
6355 sometimes @dfn{store paths}. The store has an associated database that
6356 contains information such as the store paths referred to by each store
6357 path, and the list of @emph{valid} store items---results of successful
6358 builds. This database resides in @file{@var{localstatedir}/guix/db},
6359 where @var{localstatedir} is the state directory specified @i{via}
6360 @option{--localstatedir} at configure time, usually @file{/var}.
6362 The store is @emph{always} accessed by the daemon on behalf of its clients
6363 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6364 connect to the daemon over a Unix-domain socket, send requests to it,
6365 and read the result---these are remote procedure calls, or RPCs.
6368 Users must @emph{never} modify files under @file{/gnu/store} directly.
6369 This would lead to inconsistencies and break the immutability
6370 assumptions of Guix's functional model (@pxref{Introduction}).
6372 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6373 how to check the integrity of the store and attempt recovery from
6374 accidental modifications.
6377 The @code{(guix store)} module provides procedures to connect to the
6378 daemon, and to perform RPCs. These are described below. By default,
6379 @code{open-connection}, and thus all the @command{guix} commands,
6380 connect to the local daemon or to the URI specified by the
6381 @code{GUIX_DAEMON_SOCKET} environment variable.
6383 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6384 When set, the value of this variable should be a file name or a URI
6385 designating the daemon endpoint. When it is a file name, it denotes a
6386 Unix-domain socket to connect to. In addition to file names, the
6387 supported URI schemes are:
6392 These are for Unix-domain sockets.
6393 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6394 @file{/var/guix/daemon-socket/socket}.
6397 @cindex daemon, remote access
6398 @cindex remote access to the daemon
6399 @cindex daemon, cluster setup
6400 @cindex clusters, daemon setup
6401 These URIs denote connections over TCP/IP, without encryption nor
6402 authentication of the remote host. The URI must specify the host name
6403 and optionally a port number (by default port 44146 is used):
6406 guix://master.guix.example.org:1234
6409 This setup is suitable on local networks, such as clusters, where only
6410 trusted nodes may connect to the build daemon at
6411 @code{master.guix.example.org}.
6413 The @code{--listen} option of @command{guix-daemon} can be used to
6414 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6418 @cindex SSH access to build daemons
6419 These URIs allow you to connect to a remote daemon over
6420 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6421 A typical URL might look like this:
6424 ssh://charlie@@guix.example.org:22
6427 As for @command{guix copy}, the usual OpenSSH client configuration files
6428 are honored (@pxref{Invoking guix copy}).
6431 Additional URI schemes may be supported in the future.
6433 @c XXX: Remove this note when the protocol incurs fewer round trips
6434 @c and when (guix derivations) no longer relies on file system access.
6436 The ability to connect to remote build daemons is considered
6437 experimental as of @value{VERSION}. Please get in touch with us to
6438 share any problems or suggestions you may have (@pxref{Contributing}).
6442 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6443 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6444 @var{reserve-space?} is true, instruct it to reserve a little bit of
6445 extra space on the file system so that the garbage collector can still
6446 operate should the disk become full. Return a server object.
6448 @var{file} defaults to @code{%default-socket-path}, which is the normal
6449 location given the options that were passed to @command{configure}.
6452 @deffn {Scheme Procedure} close-connection @var{server}
6453 Close the connection to @var{server}.
6456 @defvr {Scheme Variable} current-build-output-port
6457 This variable is bound to a SRFI-39 parameter, which refers to the port
6458 where build and error logs sent by the daemon should be written.
6461 Procedures that make RPCs all take a server object as their first
6464 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6465 @cindex invalid store items
6466 Return @code{#t} when @var{path} designates a valid store item and
6467 @code{#f} otherwise (an invalid item may exist on disk but still be
6468 invalid, for instance because it is the result of an aborted or failed
6471 A @code{&store-protocol-error} condition is raised if @var{path} is not
6472 prefixed by the store directory (@file{/gnu/store}).
6475 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6476 Add @var{text} under file @var{name} in the store, and return its store
6477 path. @var{references} is the list of store paths referred to by the
6478 resulting store path.
6481 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6483 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6484 file names, or derivation/output pairs, using the specified
6485 @var{mode}---@code{(build-mode normal)} by default.
6488 Note that the @code{(guix monads)} module provides a monad as well as
6489 monadic versions of the above procedures, with the goal of making it
6490 more convenient to work with code that accesses the store (@pxref{The
6494 @i{This section is currently incomplete.}
6497 @section Derivations
6500 Low-level build actions and the environment in which they are performed
6501 are represented by @dfn{derivations}. A derivation contains the
6502 following pieces of information:
6506 The outputs of the derivation---derivations produce at least one file or
6507 directory in the store, but may produce more.
6510 @cindex build-time dependencies
6511 @cindex dependencies, build-time
6512 The inputs of the derivations---i.e., its build-time dependencies---which may
6513 be other derivations or plain files in the store (patches, build scripts,
6517 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6520 The file name of a build script in the store, along with the arguments
6524 A list of environment variables to be defined.
6528 @cindex derivation path
6529 Derivations allow clients of the daemon to communicate build actions to
6530 the store. They exist in two forms: as an in-memory representation,
6531 both on the client- and daemon-side, and as files in the store whose
6532 name end in @code{.drv}---these files are referred to as @dfn{derivation
6533 paths}. Derivations paths can be passed to the @code{build-derivations}
6534 procedure to perform the build actions they prescribe (@pxref{The
6537 @cindex fixed-output derivations
6538 Operations such as file downloads and version-control checkouts for
6539 which the expected content hash is known in advance are modeled as
6540 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6541 of a fixed-output derivation are independent of its inputs---e.g., a
6542 source code download produces the same result regardless of the download
6543 method and tools being used.
6546 @cindex run-time dependencies
6547 @cindex dependencies, run-time
6548 The outputs of derivations---i.e., the build results---have a set of
6549 @dfn{references}, as reported by the @code{references} RPC or the
6550 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6551 are the set of run-time dependencies of the build results. References are a
6552 subset of the inputs of the derivation; this subset is automatically computed
6553 by the build daemon by scanning all the files in the outputs.
6555 The @code{(guix derivations)} module provides a representation of
6556 derivations as Scheme objects, along with procedures to create and
6557 otherwise manipulate derivations. The lowest-level primitive to create
6558 a derivation is the @code{derivation} procedure:
6560 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6561 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6562 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6563 [#:system (%current-system)] [#:references-graphs #f] @
6564 [#:allowed-references #f] [#:disallowed-references #f] @
6565 [#:leaked-env-vars #f] [#:local-build? #f] @
6566 [#:substitutable? #t] [#:properties '()]
6567 Build a derivation with the given arguments, and return the resulting
6568 @code{<derivation>} object.
6570 When @var{hash} and @var{hash-algo} are given, a
6571 @dfn{fixed-output derivation} is created---i.e., one whose result is
6572 known in advance, such as a file download. If, in addition,
6573 @var{recursive?} is true, then that fixed output may be an executable
6574 file or a directory and @var{hash} must be the hash of an archive
6575 containing this output.
6577 When @var{references-graphs} is true, it must be a list of file
6578 name/store path pairs. In that case, the reference graph of each store
6579 path is exported in the build environment in the corresponding file, in
6580 a simple text format.
6582 When @var{allowed-references} is true, it must be a list of store items
6583 or outputs that the derivation's output may refer to. Likewise,
6584 @var{disallowed-references}, if true, must be a list of things the
6585 outputs may @emph{not} refer to.
6587 When @var{leaked-env-vars} is true, it must be a list of strings
6588 denoting environment variables that are allowed to ``leak'' from the
6589 daemon's environment to the build environment. This is only applicable
6590 to fixed-output derivations---i.e., when @var{hash} is true. The main
6591 use is to allow variables such as @code{http_proxy} to be passed to
6592 derivations that download files.
6594 When @var{local-build?} is true, declare that the derivation is not a
6595 good candidate for offloading and should rather be built locally
6596 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6597 where the costs of data transfers would outweigh the benefits.
6599 When @var{substitutable?} is false, declare that substitutes of the
6600 derivation's output should not be used (@pxref{Substitutes}). This is
6601 useful, for instance, when building packages that capture details of the
6602 host CPU instruction set.
6604 @var{properties} must be an association list describing ``properties'' of the
6605 derivation. It is kept as-is, uninterpreted, in the derivation.
6609 Here's an example with a shell script as its builder, assuming
6610 @var{store} is an open connection to the daemon, and @var{bash} points
6611 to a Bash executable in the store:
6614 (use-modules (guix utils)
6618 (let ((builder ; add the Bash script to the store
6619 (add-text-to-store store "my-builder.sh"
6620 "echo hello world > $out\n" '())))
6621 (derivation store "foo"
6622 bash `("-e" ,builder)
6623 #:inputs `((,bash) (,builder))
6624 #:env-vars '(("HOME" . "/homeless"))))
6625 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6628 As can be guessed, this primitive is cumbersome to use directly. A
6629 better approach is to write build scripts in Scheme, of course! The
6630 best course of action for that is to write the build code as a
6631 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6632 information, @pxref{G-Expressions}.
6634 Once upon a time, @code{gexp->derivation} did not exist and constructing
6635 derivations with build code written in Scheme was achieved with
6636 @code{build-expression->derivation}, documented below. This procedure
6637 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6639 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6640 @var{name} @var{exp} @
6641 [#:system (%current-system)] [#:inputs '()] @
6642 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6643 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6644 [#:references-graphs #f] [#:allowed-references #f] @
6645 [#:disallowed-references #f] @
6646 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6647 Return a derivation that executes Scheme expression @var{exp} as a
6648 builder for derivation @var{name}. @var{inputs} must be a list of
6649 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6650 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6651 modules from the current search path to be copied in the store,
6652 compiled, and made available in the load path during the execution of
6653 @var{exp}---e.g., @code{((guix build utils) (guix build
6654 gnu-build-system))}.
6656 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6657 to a list of output/path pairs, and where @code{%build-inputs} is bound
6658 to a list of string/output-path pairs made from @var{inputs}.
6659 Optionally, @var{env-vars} is a list of string pairs specifying the name
6660 and value of environment variables visible to the builder. The builder
6661 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6662 @var{exp} returns @code{#f}, the build is considered to have failed.
6664 @var{exp} is built using @var{guile-for-build} (a derivation). When
6665 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6666 @code{%guile-for-build} fluid is used instead.
6668 See the @code{derivation} procedure for the meaning of
6669 @var{references-graphs}, @var{allowed-references},
6670 @var{disallowed-references}, @var{local-build?}, and
6671 @var{substitutable?}.
6675 Here's an example of a single-output derivation that creates a directory
6676 containing one file:
6679 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6680 (mkdir out) ; create /gnu/store/@dots{}-goo
6681 (call-with-output-file (string-append out "/test")
6683 (display '(hello guix) p))))))
6684 (build-expression->derivation store "goo" builder))
6686 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6690 @node The Store Monad
6691 @section The Store Monad
6695 The procedures that operate on the store described in the previous
6696 sections all take an open connection to the build daemon as their first
6697 argument. Although the underlying model is functional, they either have
6698 side effects or depend on the current state of the store.
6700 The former is inconvenient: the connection to the build daemon has to be
6701 carried around in all those functions, making it impossible to compose
6702 functions that do not take that parameter with functions that do. The
6703 latter can be problematic: since store operations have side effects
6704 and/or depend on external state, they have to be properly sequenced.
6706 @cindex monadic values
6707 @cindex monadic functions
6708 This is where the @code{(guix monads)} module comes in. This module
6709 provides a framework for working with @dfn{monads}, and a particularly
6710 useful monad for our uses, the @dfn{store monad}. Monads are a
6711 construct that allows two things: associating ``context'' with values
6712 (in our case, the context is the store), and building sequences of
6713 computations (here computations include accesses to the store). Values
6714 in a monad---values that carry this additional context---are called
6715 @dfn{monadic values}; procedures that return such values are called
6716 @dfn{monadic procedures}.
6718 Consider this ``normal'' procedure:
6721 (define (sh-symlink store)
6722 ;; Return a derivation that symlinks the 'bash' executable.
6723 (let* ((drv (package-derivation store bash))
6724 (out (derivation->output-path drv))
6725 (sh (string-append out "/bin/bash")))
6726 (build-expression->derivation store "sh"
6727 `(symlink ,sh %output))))
6730 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6731 as a monadic function:
6734 (define (sh-symlink)
6735 ;; Same, but return a monadic value.
6736 (mlet %store-monad ((drv (package->derivation bash)))
6737 (gexp->derivation "sh"
6738 #~(symlink (string-append #$drv "/bin/bash")
6742 There are several things to note in the second version: the @code{store}
6743 parameter is now implicit and is ``threaded'' in the calls to the
6744 @code{package->derivation} and @code{gexp->derivation} monadic
6745 procedures, and the monadic value returned by @code{package->derivation}
6746 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6748 As it turns out, the call to @code{package->derivation} can even be
6749 omitted since it will take place implicitly, as we will see later
6750 (@pxref{G-Expressions}):
6753 (define (sh-symlink)
6754 (gexp->derivation "sh"
6755 #~(symlink (string-append #$bash "/bin/bash")
6760 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6761 @c for the funny quote.
6762 Calling the monadic @code{sh-symlink} has no effect. As someone once
6763 said, ``you exit a monad like you exit a building on fire: by running''.
6764 So, to exit the monad and get the desired effect, one must use
6765 @code{run-with-store}:
6768 (run-with-store (open-connection) (sh-symlink))
6769 @result{} /gnu/store/...-sh-symlink
6772 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6773 new ``meta-commands'' to make it easier to deal with monadic procedures:
6774 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6775 to ``run'' a single monadic value through the store:
6778 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6779 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6782 The latter enters a recursive REPL, where all the return values are
6783 automatically run through the store:
6786 scheme@@(guile-user)> ,enter-store-monad
6787 store-monad@@(guile-user) [1]> (package->derivation hello)
6788 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6789 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6790 $3 = "/gnu/store/@dots{}-foo"
6791 store-monad@@(guile-user) [1]> ,q
6792 scheme@@(guile-user)>
6796 Note that non-monadic values cannot be returned in the
6797 @code{store-monad} REPL.
6799 The main syntactic forms to deal with monads in general are provided by
6800 the @code{(guix monads)} module and are described below.
6802 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6803 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6807 @deffn {Scheme Syntax} return @var{val}
6808 Return a monadic value that encapsulates @var{val}.
6811 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6812 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6813 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6814 referred to as ``bind'', but that name denotes an unrelated procedure in
6815 Guile. Thus we use this somewhat cryptic symbol inherited from the
6816 Haskell language.}. There can be one @var{mproc} or several of them, as
6821 (with-monad %state-monad
6823 (lambda (x) (return (+ 1 x)))
6824 (lambda (x) (return (* 2 x)))))
6828 @result{} some-state
6832 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6834 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6836 Bind the variables @var{var} to the monadic values @var{mval} in
6837 @var{body}, which is a sequence of expressions. As with the bind
6838 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6839 value ``contained'' in @var{mval} and making @var{var} refer to that
6840 raw, non-monadic value within the scope of the @var{body}. The form
6841 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6842 @var{val}, as per @code{let}. The binding operations occur in sequence
6843 from left to right. The last expression of @var{body} must be a monadic
6844 expression, and its result will become the result of the @code{mlet} or
6845 @code{mlet*} when run in the @var{monad}.
6847 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6848 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6851 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6852 Bind @var{mexp} and the following monadic expressions in sequence,
6853 returning the result of the last expression. Every expression in the
6854 sequence must be a monadic expression.
6856 This is akin to @code{mlet}, except that the return values of the
6857 monadic expressions are ignored. In that sense, it is analogous to
6858 @code{begin}, but applied to monadic expressions.
6861 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6862 When @var{condition} is true, evaluate the sequence of monadic
6863 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6864 @var{condition} is false, return @code{*unspecified*} in the current
6865 monad. Every expression in the sequence must be a monadic expression.
6868 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6869 When @var{condition} is false, evaluate the sequence of monadic
6870 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6871 @var{condition} is true, return @code{*unspecified*} in the current
6872 monad. Every expression in the sequence must be a monadic expression.
6876 The @code{(guix monads)} module provides the @dfn{state monad}, which
6877 allows an additional value---the state---to be @emph{threaded} through
6878 monadic procedure calls.
6880 @defvr {Scheme Variable} %state-monad
6881 The state monad. Procedures in the state monad can access and change
6882 the state that is threaded.
6884 Consider the example below. The @code{square} procedure returns a value
6885 in the state monad. It returns the square of its argument, but also
6886 increments the current state value:
6890 (mlet %state-monad ((count (current-state)))
6891 (mbegin %state-monad
6892 (set-current-state (+ 1 count))
6895 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6900 When ``run'' through @var{%state-monad}, we obtain that additional state
6901 value, which is the number of @code{square} calls.
6904 @deffn {Monadic Procedure} current-state
6905 Return the current state as a monadic value.
6908 @deffn {Monadic Procedure} set-current-state @var{value}
6909 Set the current state to @var{value} and return the previous state as a
6913 @deffn {Monadic Procedure} state-push @var{value}
6914 Push @var{value} to the current state, which is assumed to be a list,
6915 and return the previous state as a monadic value.
6918 @deffn {Monadic Procedure} state-pop
6919 Pop a value from the current state and return it as a monadic value.
6920 The state is assumed to be a list.
6923 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6924 Run monadic value @var{mval} starting with @var{state} as the initial
6925 state. Return two values: the resulting value, and the resulting state.
6928 The main interface to the store monad, provided by the @code{(guix
6929 store)} module, is as follows.
6931 @defvr {Scheme Variable} %store-monad
6932 The store monad---an alias for @var{%state-monad}.
6934 Values in the store monad encapsulate accesses to the store. When its
6935 effect is needed, a value of the store monad must be ``evaluated'' by
6936 passing it to the @code{run-with-store} procedure (see below.)
6939 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6940 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6941 open store connection.
6944 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6945 Return as a monadic value the absolute file name in the store of the file
6946 containing @var{text}, a string. @var{references} is a list of store items that the
6947 resulting text file refers to; it defaults to the empty list.
6950 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6951 Return as a monadic value the absolute file name in the store of the file
6952 containing @var{data}, a bytevector. @var{references} is a list of store
6953 items that the resulting binary file refers to; it defaults to the empty list.
6956 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6957 [#:recursive? #t] [#:select? (const #t)]
6958 Return the name of @var{file} once interned in the store. Use
6959 @var{name} as its store name, or the basename of @var{file} if
6960 @var{name} is omitted.
6962 When @var{recursive?} is true, the contents of @var{file} are added
6963 recursively; if @var{file} designates a flat file and @var{recursive?}
6964 is true, its contents are added, and its permission bits are kept.
6966 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
6967 @var{stat})} for each directory entry, where @var{file} is the entry's
6968 absolute file name and @var{stat} is the result of @code{lstat}; exclude
6969 entries for which @var{select?} does not return true.
6971 The example below adds a file to the store, under two different names:
6974 (run-with-store (open-connection)
6975 (mlet %store-monad ((a (interned-file "README"))
6976 (b (interned-file "README" "LEGU-MIN")))
6977 (return (list a b))))
6979 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
6984 The @code{(guix packages)} module exports the following package-related
6987 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
6988 [#:system (%current-system)] [#:target #f] @
6991 value in the absolute file name of @var{file} within the @var{output}
6992 directory of @var{package}. When @var{file} is omitted, return the name
6993 of the @var{output} directory of @var{package}. When @var{target} is
6994 true, use it as a cross-compilation target triplet.
6997 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
6998 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
6999 @var{target} [@var{system}]
7000 Monadic version of @code{package-derivation} and
7001 @code{package-cross-derivation} (@pxref{Defining Packages}).
7006 @section G-Expressions
7008 @cindex G-expression
7009 @cindex build code quoting
7010 So we have ``derivations'', which represent a sequence of build actions
7011 to be performed to produce an item in the store (@pxref{Derivations}).
7012 These build actions are performed when asking the daemon to actually
7013 build the derivations; they are run by the daemon in a container
7014 (@pxref{Invoking guix-daemon}).
7016 @cindex strata of code
7017 It should come as no surprise that we like to write these build actions
7018 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7019 code@footnote{The term @dfn{stratum} in this context was coined by
7020 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7021 Kiselyov, who has written insightful
7022 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7023 on this topic}, refers to this kind of code generation as
7024 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7025 to the daemon, etc.---and the ``build code''---code that actually
7026 performs build actions, such as making directories, invoking
7027 @command{make}, etc.
7029 To describe a derivation and its build actions, one typically needs to
7030 embed build code inside host code. It boils down to manipulating build
7031 code as data, and the homoiconicity of Scheme---code has a direct
7032 representation as data---comes in handy for that. But we need more than
7033 the normal @code{quasiquote} mechanism in Scheme to construct build
7036 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7037 S-expressions adapted to build expressions. G-expressions, or
7038 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7039 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7040 @code{#$}, and @code{#$@@}), which are comparable to
7041 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7042 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7043 GNU Guile Reference Manual}). However, there are major differences:
7047 Gexps are meant to be written to a file and run or manipulated by other
7051 When a high-level object such as a package or derivation is unquoted
7052 inside a gexp, the result is as if its output file name had been
7056 Gexps carry information about the packages or derivations they refer to,
7057 and these dependencies are automatically added as inputs to the build
7058 processes that use them.
7061 @cindex lowering, of high-level objects in gexps
7062 This mechanism is not limited to package and derivation
7063 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7064 derivations or files in the store can be defined,
7065 such that these objects can also be inserted
7066 into gexps. For example, a useful type of high-level objects that can be
7067 inserted in a gexp is ``file-like objects'', which make it easy to
7068 add files to the store and to refer to them in
7069 derivations and such (see @code{local-file} and @code{plain-file}
7072 To illustrate the idea, here is an example of a gexp:
7079 (symlink (string-append #$coreutils "/bin/ls")
7083 This gexp can be passed to @code{gexp->derivation}; we obtain a
7084 derivation that builds a directory containing exactly one symlink to
7085 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7088 (gexp->derivation "the-thing" build-exp)
7091 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7092 substituted to the reference to the @var{coreutils} package in the
7093 actual build code, and @var{coreutils} is automatically made an input to
7094 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7095 output)}) is replaced by a string containing the directory name of the
7096 output of the derivation.
7098 @cindex cross compilation
7099 In a cross-compilation context, it is useful to distinguish between
7100 references to the @emph{native} build of a package---that can run on the
7101 host---versus references to cross builds of a package. To that end, the
7102 @code{#+} plays the same role as @code{#$}, but is a reference to a
7103 native package build:
7106 (gexp->derivation "vi"
7109 (system* (string-append #+coreutils "/bin/ln")
7111 (string-append #$emacs "/bin/emacs")
7112 (string-append #$output "/bin/vi")))
7113 #:target "mips64el-linux-gnu")
7117 In the example above, the native build of @var{coreutils} is used, so
7118 that @command{ln} can actually run on the host; but then the
7119 cross-compiled build of @var{emacs} is referenced.
7121 @cindex imported modules, for gexps
7122 @findex with-imported-modules
7123 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7124 able to use certain Guile modules from the ``host environment'' in the
7125 gexp, so those modules should be imported in the ``build environment''.
7126 The @code{with-imported-modules} form allows you to express that:
7129 (let ((build (with-imported-modules '((guix build utils))
7131 (use-modules (guix build utils))
7132 (mkdir-p (string-append #$output "/bin"))))))
7133 (gexp->derivation "empty-dir"
7136 (display "success!\n")
7141 In this example, the @code{(guix build utils)} module is automatically
7142 pulled into the isolated build environment of our gexp, such that
7143 @code{(use-modules (guix build utils))} works as expected.
7145 @cindex module closure
7146 @findex source-module-closure
7147 Usually you want the @emph{closure} of the module to be imported---i.e.,
7148 the module itself and all the modules it depends on---rather than just
7149 the module; failing to do that, attempts to use the module will fail
7150 because of missing dependent modules. The @code{source-module-closure}
7151 procedure computes the closure of a module by looking at its source file
7152 headers, which comes in handy in this case:
7155 (use-modules (guix modules)) ;for 'source-module-closure'
7157 (with-imported-modules (source-module-closure
7158 '((guix build utils)
7160 (gexp->derivation "something-with-vms"
7162 (use-modules (guix build utils)
7167 @cindex extensions, for gexps
7168 @findex with-extensions
7169 In the same vein, sometimes you want to import not just pure-Scheme
7170 modules, but also ``extensions'' such as Guile bindings to C libraries
7171 or other ``full-blown'' packages. Say you need the @code{guile-json}
7172 package available on the build side, here's how you would do it:
7175 (use-modules (gnu packages guile)) ;for 'guile-json'
7177 (with-extensions (list guile-json)
7178 (gexp->derivation "something-with-json"
7180 (use-modules (json))
7184 The syntactic form to construct gexps is summarized below.
7186 @deffn {Scheme Syntax} #~@var{exp}
7187 @deffnx {Scheme Syntax} (gexp @var{exp})
7188 Return a G-expression containing @var{exp}. @var{exp} may contain one
7189 or more of the following forms:
7193 @itemx (ungexp @var{obj})
7194 Introduce a reference to @var{obj}. @var{obj} may have one of the
7195 supported types, for example a package or a
7196 derivation, in which case the @code{ungexp} form is replaced by its
7197 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7199 If @var{obj} is a list, it is traversed and references to supported
7200 objects are substituted similarly.
7202 If @var{obj} is another gexp, its contents are inserted and its
7203 dependencies are added to those of the containing gexp.
7205 If @var{obj} is another kind of object, it is inserted as is.
7207 @item #$@var{obj}:@var{output}
7208 @itemx (ungexp @var{obj} @var{output})
7209 This is like the form above, but referring explicitly to the
7210 @var{output} of @var{obj}---this is useful when @var{obj} produces
7211 multiple outputs (@pxref{Packages with Multiple Outputs}).
7214 @itemx #+@var{obj}:output
7215 @itemx (ungexp-native @var{obj})
7216 @itemx (ungexp-native @var{obj} @var{output})
7217 Same as @code{ungexp}, but produces a reference to the @emph{native}
7218 build of @var{obj} when used in a cross compilation context.
7220 @item #$output[:@var{output}]
7221 @itemx (ungexp output [@var{output}])
7222 Insert a reference to derivation output @var{output}, or to the main
7223 output when @var{output} is omitted.
7225 This only makes sense for gexps passed to @code{gexp->derivation}.
7228 @itemx (ungexp-splicing @var{lst})
7229 Like the above, but splices the contents of @var{lst} inside the
7233 @itemx (ungexp-native-splicing @var{lst})
7234 Like the above, but refers to native builds of the objects listed in
7239 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7240 of the @code{gexp?} type (see below.)
7243 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7244 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7245 in their execution environment.
7247 Each item in @var{modules} can be the name of a module, such as
7248 @code{(guix build utils)}, or it can be a module name, followed by an
7249 arrow, followed by a file-like object:
7252 `((guix build utils)
7254 ((guix config) => ,(scheme-file "config.scm"
7255 #~(define-module @dots{}))))
7259 In the example above, the first two modules are taken from the search
7260 path, and the last one is created from the given file-like object.
7262 This form has @emph{lexical} scope: it has an effect on the gexps
7263 directly defined in @var{body}@dots{}, but not on those defined, say, in
7264 procedures called from @var{body}@dots{}.
7267 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7268 Mark the gexps defined in @var{body}@dots{} as requiring
7269 @var{extensions} in their build and execution environment.
7270 @var{extensions} is typically a list of package objects such as those
7271 defined in the @code{(gnu packages guile)} module.
7273 Concretely, the packages listed in @var{extensions} are added to the
7274 load path while compiling imported modules in @var{body}@dots{}; they
7275 are also added to the load path of the gexp returned by
7279 @deffn {Scheme Procedure} gexp? @var{obj}
7280 Return @code{#t} if @var{obj} is a G-expression.
7283 G-expressions are meant to be written to disk, either as code building
7284 some derivation, or as plain files in the store. The monadic procedures
7285 below allow you to do that (@pxref{The Store Monad}, for more
7286 information about monads.)
7288 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7289 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7290 [#:hash #f] [#:hash-algo #f] @
7291 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7292 [#:module-path @var{%load-path}] @
7293 [#:effective-version "2.2"] @
7294 [#:references-graphs #f] [#:allowed-references #f] @
7295 [#:disallowed-references #f] @
7296 [#:leaked-env-vars #f] @
7297 [#:script-name (string-append @var{name} "-builder")] @
7298 [#:deprecation-warnings #f] @
7299 [#:local-build? #f] [#:substitutable? #t] @
7300 [#:properties '()] [#:guile-for-build #f]
7301 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7302 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7303 stored in a file called @var{script-name}. When @var{target} is true,
7304 it is used as the cross-compilation target triplet for packages referred
7307 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7309 make @var{modules} available in the evaluation context of @var{exp};
7310 @var{modules} is a list of names of Guile modules searched in
7311 @var{module-path} to be copied in the store, compiled, and made available in
7312 the load path during the execution of @var{exp}---e.g., @code{((guix
7313 build utils) (guix build gnu-build-system))}.
7315 @var{effective-version} determines the string to use when adding extensions of
7316 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7318 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7321 When @var{references-graphs} is true, it must be a list of tuples of one of the
7325 (@var{file-name} @var{package})
7326 (@var{file-name} @var{package} @var{output})
7327 (@var{file-name} @var{derivation})
7328 (@var{file-name} @var{derivation} @var{output})
7329 (@var{file-name} @var{store-item})
7332 The right-hand-side of each element of @var{references-graphs} is automatically made
7333 an input of the build process of @var{exp}. In the build environment, each
7334 @var{file-name} contains the reference graph of the corresponding item, in a simple
7337 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7338 In the latter case, the list denotes store items that the result is allowed to
7339 refer to. Any reference to another store item will lead to a build error.
7340 Similarly for @var{disallowed-references}, which can list items that must not be
7341 referenced by the outputs.
7343 @var{deprecation-warnings} determines whether to show deprecation warnings while
7344 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7346 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7349 @cindex file-like objects
7350 The @code{local-file}, @code{plain-file}, @code{computed-file},
7351 @code{program-file}, and @code{scheme-file} procedures below return
7352 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7353 these objects lead to a file in the store. Consider this G-expression:
7356 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7357 #$(local-file "/tmp/my-nscd.conf"))
7360 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7361 to the store. Once expanded, for instance @i{via}
7362 @code{gexp->derivation}, the G-expression refers to that copy under
7363 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7364 does not have any effect on what the G-expression does.
7365 @code{plain-file} can be used similarly; it differs in that the file
7366 content is directly passed as a string.
7368 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7369 [#:recursive? #f] [#:select? (const #t)]
7370 Return an object representing local file @var{file} to add to the store; this
7371 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7372 up relative to the source file where this form appears. @var{file} will be added to
7373 the store under @var{name}--by default the base name of @var{file}.
7375 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7376 designates a flat file and @var{recursive?} is true, its contents are added, and its
7377 permission bits are kept.
7379 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7380 @var{stat})} for each directory entry, where @var{file} is the entry's
7381 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7382 entries for which @var{select?} does not return true.
7384 This is the declarative counterpart of the @code{interned-file} monadic
7385 procedure (@pxref{The Store Monad, @code{interned-file}}).
7388 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7389 Return an object representing a text file called @var{name} with the given
7390 @var{content} (a string or a bytevector) to be added to the store.
7392 This is the declarative counterpart of @code{text-file}.
7395 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7396 [#:options '(#:local-build? #t)]
7397 Return an object representing the store item @var{name}, a file or
7398 directory computed by @var{gexp}. @var{options}
7399 is a list of additional arguments to pass to @code{gexp->derivation}.
7401 This is the declarative counterpart of @code{gexp->derivation}.
7404 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7405 [#:guile (default-guile)] [#:module-path %load-path]
7406 Return an executable script @var{name} that runs @var{exp} using
7407 @var{guile}, with @var{exp}'s imported modules in its search path.
7408 Look up @var{exp}'s modules in @var{module-path}.
7410 The example below builds a script that simply invokes the @command{ls}
7414 (use-modules (guix gexp) (gnu packages base))
7416 (gexp->script "list-files"
7417 #~(execl #$(file-append coreutils "/bin/ls")
7421 When ``running'' it through the store (@pxref{The Store Monad,
7422 @code{run-with-store}}), we obtain a derivation that produces an
7423 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7426 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7428 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7432 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7433 [#:guile #f] [#:module-path %load-path]
7434 Return an object representing the executable store item @var{name} that
7435 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7436 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7438 This is the declarative counterpart of @code{gexp->script}.
7441 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7442 [#:set-load-path? #t] [#:module-path %load-path] @
7444 [#:guile (default-guile)]
7445 Return a derivation that builds a file @var{name} containing @var{exp}.
7446 When @var{splice?} is true, @var{exp} is considered to be a list of
7447 expressions that will be spliced in the resulting file.
7449 When @var{set-load-path?} is true, emit code in the resulting file to
7450 set @code{%load-path} and @code{%load-compiled-path} to honor
7451 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7454 The resulting file holds references to all the dependencies of @var{exp}
7455 or a subset thereof.
7458 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7459 Return an object representing the Scheme file @var{name} that contains
7462 This is the declarative counterpart of @code{gexp->file}.
7465 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7466 Return as a monadic value a derivation that builds a text file
7467 containing all of @var{text}. @var{text} may list, in addition to
7468 strings, objects of any type that can be used in a gexp: packages,
7469 derivations, local file objects, etc. The resulting store file holds
7470 references to all these.
7472 This variant should be preferred over @code{text-file} anytime the file
7473 to create will reference items from the store. This is typically the
7474 case when building a configuration file that embeds store file names,
7478 (define (profile.sh)
7479 ;; Return the name of a shell script in the store that
7480 ;; initializes the 'PATH' environment variable.
7481 (text-file* "profile.sh"
7482 "export PATH=" coreutils "/bin:"
7483 grep "/bin:" sed "/bin\n"))
7486 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7487 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7488 preventing them from being garbage-collected during its lifetime.
7491 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7492 Return an object representing store file @var{name} containing
7493 @var{text}. @var{text} is a sequence of strings and file-like objects,
7497 (mixed-text-file "profile"
7498 "export PATH=" coreutils "/bin:" grep "/bin")
7501 This is the declarative counterpart of @code{text-file*}.
7504 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7505 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7506 Each item in @var{files} must be a two-element list where the first element is the
7507 file name to use in the new directory, and the second element is a gexp
7508 denoting the target file. Here's an example:
7512 `(("hosts" ,(plain-file "hosts"
7513 "127.0.0.1 localhost"))
7514 ("bashrc" ,(plain-file "bashrc"
7515 "alias ls='ls --color=auto'"))))
7518 This yields an @code{etc} directory containing these two files.
7521 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7522 Return a directory that is the union of @var{things}, where @var{things} is a list of
7523 file-like objects denoting directories. For example:
7526 (directory-union "guile+emacs" (list guile emacs))
7529 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7532 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7533 Return a file-like object that expands to the concatenation of @var{obj}
7534 and @var{suffix}, where @var{obj} is a lowerable object and each
7535 @var{suffix} is a string.
7537 As an example, consider this gexp:
7540 (gexp->script "run-uname"
7541 #~(system* #$(file-append coreutils
7545 The same effect could be achieved with:
7548 (gexp->script "run-uname"
7549 #~(system* (string-append #$coreutils
7553 There is one difference though: in the @code{file-append} case, the
7554 resulting script contains the absolute file name as a string, whereas in
7555 the second case, the resulting script contains a @code{(string-append
7556 @dots{})} expression to construct the file name @emph{at run time}.
7560 Of course, in addition to gexps embedded in ``host'' code, there are
7561 also modules containing build tools. To make it clear that they are
7562 meant to be used in the build stratum, these modules are kept in the
7563 @code{(guix build @dots{})} name space.
7565 @cindex lowering, of high-level objects in gexps
7566 Internally, high-level objects are @dfn{lowered}, using their compiler,
7567 to either derivations or store items. For instance, lowering a package
7568 yields a derivation, and lowering a @code{plain-file} yields a store
7569 item. This is achieved using the @code{lower-object} monadic procedure.
7571 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7573 Return as a value in @var{%store-monad} the derivation or store item
7574 corresponding to @var{obj} for @var{system}, cross-compiling for
7575 @var{target} if @var{target} is true. @var{obj} must be an object that
7576 has an associated gexp compiler, such as a @code{<package>}.
7579 @node Invoking guix repl
7580 @section Invoking @command{guix repl}
7582 @cindex REPL, read-eval-print loop
7583 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7584 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7585 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7586 command, @command{guix repl} guarantees that all the Guix modules and all its
7587 dependencies are available in the search path. You can use it this way:
7591 scheme@@(guile-user)> ,use (gnu packages base)
7592 scheme@@(guile-user)> coreutils
7593 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7597 In addition, @command{guix repl} implements a simple machine-readable REPL
7598 protocol for use by @code{(guix inferior)}, a facility to interact with
7599 @dfn{inferiors}, separate processes running a potentially different revision
7602 The available options are as follows:
7605 @item --type=@var{type}
7606 @itemx -t @var{type}
7607 Start a REPL of the given @var{TYPE}, which can be one of the following:
7611 This is default, and it spawns a standard full-featured Guile REPL.
7613 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7614 that the @code{(guix inferior)} module speaks.
7617 @item --listen=@var{endpoint}
7618 By default, @command{guix repl} reads from standard input and writes to
7619 standard output. When this option is passed, it will instead listen for
7620 connections on @var{endpoint}. Here are examples of valid options:
7623 @item --listen=tcp:37146
7624 Accept connections on localhost on port 37146.
7626 @item --listen=unix:/tmp/socket
7627 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7631 @c *********************************************************************
7635 This section describes Guix command-line utilities. Some of them are
7636 primarily targeted at developers and users who write new package
7637 definitions, while others are more generally useful. They complement
7638 the Scheme programming interface of Guix in a convenient way.
7641 * Invoking guix build:: Building packages from the command line.
7642 * Invoking guix edit:: Editing package definitions.
7643 * Invoking guix download:: Downloading a file and printing its hash.
7644 * Invoking guix hash:: Computing the cryptographic hash of a file.
7645 * Invoking guix import:: Importing package definitions.
7646 * Invoking guix refresh:: Updating package definitions.
7647 * Invoking guix lint:: Finding errors in package definitions.
7648 * Invoking guix size:: Profiling disk usage.
7649 * Invoking guix graph:: Visualizing the graph of packages.
7650 * Invoking guix publish:: Sharing substitutes.
7651 * Invoking guix challenge:: Challenging substitute servers.
7652 * Invoking guix copy:: Copying to and from a remote store.
7653 * Invoking guix container:: Process isolation.
7654 * Invoking guix weather:: Assessing substitute availability.
7655 * Invoking guix processes:: Listing client processes.
7658 @node Invoking guix build
7659 @section Invoking @command{guix build}
7661 @cindex package building
7662 @cindex @command{guix build}
7663 The @command{guix build} command builds packages or derivations and
7664 their dependencies, and prints the resulting store paths. Note that it
7665 does not modify the user's profile---this is the job of the
7666 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7667 it is mainly useful for distribution developers.
7669 The general syntax is:
7672 guix build @var{options} @var{package-or-derivation}@dots{}
7675 As an example, the following command builds the latest versions of Emacs
7676 and of Guile, displays their build logs, and finally displays the
7677 resulting directories:
7680 guix build emacs guile
7683 Similarly, the following command builds all the available packages:
7686 guix build --quiet --keep-going \
7687 `guix package -A | cut -f1,2 --output-delimiter=@@`
7690 @var{package-or-derivation} may be either the name of a package found in
7691 the software distribution such as @code{coreutils} or
7692 @code{coreutils@@8.20}, or a derivation such as
7693 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7694 package with the corresponding name (and optionally version) is searched
7695 for among the GNU distribution modules (@pxref{Package Modules}).
7697 Alternatively, the @code{--expression} option may be used to specify a
7698 Scheme expression that evaluates to a package; this is useful when
7699 disambiguating among several same-named packages or package variants is
7702 There may be zero or more @var{options}. The available options are
7703 described in the subsections below.
7706 * Common Build Options:: Build options for most commands.
7707 * Package Transformation Options:: Creating variants of packages.
7708 * Additional Build Options:: Options specific to 'guix build'.
7709 * Debugging Build Failures:: Real life packaging experience.
7712 @node Common Build Options
7713 @subsection Common Build Options
7715 A number of options that control the build process are common to
7716 @command{guix build} and other commands that can spawn builds, such as
7717 @command{guix package} or @command{guix archive}. These are the
7722 @item --load-path=@var{directory}
7723 @itemx -L @var{directory}
7724 Add @var{directory} to the front of the package module search path
7725 (@pxref{Package Modules}).
7727 This allows users to define their own packages and make them visible to
7728 the command-line tools.
7732 Keep the build tree of failed builds. Thus, if a build fails, its build
7733 tree is kept under @file{/tmp}, in a directory whose name is shown at
7734 the end of the build log. This is useful when debugging build issues.
7735 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7738 This option has no effect when connecting to a remote daemon with a
7739 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7744 Keep going when some of the derivations fail to build; return only once
7745 all the builds have either completed or failed.
7747 The default behavior is to stop as soon as one of the specified
7748 derivations has failed.
7752 Do not build the derivations.
7754 @anchor{fallback-option}
7756 When substituting a pre-built binary fails, fall back to building
7757 packages locally (@pxref{Substitution Failure}).
7759 @item --substitute-urls=@var{urls}
7760 @anchor{client-substitute-urls}
7761 Consider @var{urls} the whitespace-separated list of substitute source
7762 URLs, overriding the default list of URLs of @command{guix-daemon}
7763 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7765 This means that substitutes may be downloaded from @var{urls}, provided
7766 they are signed by a key authorized by the system administrator
7767 (@pxref{Substitutes}).
7769 When @var{urls} is the empty string, substitutes are effectively
7772 @item --no-substitutes
7773 Do not use substitutes for build products. That is, always build things
7774 locally instead of allowing downloads of pre-built binaries
7775 (@pxref{Substitutes}).
7778 Do not ``graft'' packages. In practice, this means that package updates
7779 available as grafts are not applied. @xref{Security Updates}, for more
7780 information on grafts.
7782 @item --rounds=@var{n}
7783 Build each derivation @var{n} times in a row, and raise an error if
7784 consecutive build results are not bit-for-bit identical.
7786 This is a useful way to detect non-deterministic builds processes.
7787 Non-deterministic build processes are a problem because they make it
7788 practically impossible for users to @emph{verify} whether third-party
7789 binaries are genuine. @xref{Invoking guix challenge}, for more.
7791 Note that, currently, the differing build results are not kept around,
7792 so you will have to manually investigate in case of an error---e.g., by
7793 stashing one of the build results with @code{guix archive --export}
7794 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7797 @item --no-build-hook
7798 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7799 (@pxref{Daemon Offload Setup}). That is, always build things locally
7800 instead of offloading builds to remote machines.
7802 @item --max-silent-time=@var{seconds}
7803 When the build or substitution process remains silent for more than
7804 @var{seconds}, terminate it and report a build failure.
7806 By default, the daemon's setting is honored (@pxref{Invoking
7807 guix-daemon, @code{--max-silent-time}}).
7809 @item --timeout=@var{seconds}
7810 Likewise, when the build or substitution process lasts for more than
7811 @var{seconds}, terminate it and report a build failure.
7813 By default, the daemon's setting is honored (@pxref{Invoking
7814 guix-daemon, @code{--timeout}}).
7816 @c Note: This option is actually not part of %standard-build-options but
7817 @c most programs honor it.
7818 @cindex verbosity, of the command-line tools
7819 @cindex build logs, verbosity
7820 @item -v @var{level}
7821 @itemx --verbosity=@var{level}
7822 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7823 output is produced, 1 is for quiet output, and 2 shows all the build log
7824 output on standard error.
7826 @item --cores=@var{n}
7828 Allow the use of up to @var{n} CPU cores for the build. The special
7829 value @code{0} means to use as many CPU cores as available.
7831 @item --max-jobs=@var{n}
7833 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7834 guix-daemon, @code{--max-jobs}}, for details about this option and the
7835 equivalent @command{guix-daemon} option.
7837 @item --debug=@var{level}
7838 Produce debugging output coming from the build daemon. @var{level} must be an
7839 integer between 0 and 5; higher means more verbose output. Setting a level of
7840 4 or more may be helpful when debugging setup issues with the build daemon.
7844 Behind the scenes, @command{guix build} is essentially an interface to
7845 the @code{package-derivation} procedure of the @code{(guix packages)}
7846 module, and to the @code{build-derivations} procedure of the @code{(guix
7847 derivations)} module.
7849 In addition to options explicitly passed on the command line,
7850 @command{guix build} and other @command{guix} commands that support
7851 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7853 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7854 Users can define this variable to a list of command line options that
7855 will automatically be used by @command{guix build} and other
7856 @command{guix} commands that can perform builds, as in the example
7860 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7863 These options are parsed independently, and the result is appended to
7864 the parsed command-line options.
7868 @node Package Transformation Options
7869 @subsection Package Transformation Options
7871 @cindex package variants
7872 Another set of command-line options supported by @command{guix build}
7873 and also @command{guix package} are @dfn{package transformation
7874 options}. These are options that make it possible to define @dfn{package
7875 variants}---for instance, packages built from different source code.
7876 This is a convenient way to create customized packages on the fly
7877 without having to type in the definitions of package variants
7878 (@pxref{Defining Packages}).
7882 @item --with-source=@var{source}
7883 @itemx --with-source=@var{package}=@var{source}
7884 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7885 Use @var{source} as the source of @var{package}, and @var{version} as
7887 @var{source} must be a file name or a URL, as for @command{guix
7888 download} (@pxref{Invoking guix download}).
7890 When @var{package} is omitted,
7891 it is taken to be the package name specified on the
7892 command line that matches the base of @var{source}---e.g.,
7893 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7894 package is @code{guile}.
7896 Likewise, when @var{version} is omitted, the version string is inferred from
7897 @var{source}; in the previous example, it is @code{2.0.10}.
7899 This option allows users to try out versions of packages other than the
7900 one provided by the distribution. The example below downloads
7901 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7902 the @code{ed} package:
7905 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7908 As a developer, @code{--with-source} makes it easy to test release
7912 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7915 @dots{} or to build from a checkout in a pristine environment:
7918 $ git clone git://git.sv.gnu.org/guix.git
7919 $ guix build guix --with-source=guix@@1.0=./guix
7922 @item --with-input=@var{package}=@var{replacement}
7923 Replace dependency on @var{package} by a dependency on
7924 @var{replacement}. @var{package} must be a package name, and
7925 @var{replacement} must be a package specification such as @code{guile}
7926 or @code{guile@@1.8}.
7928 For instance, the following command builds Guix, but replaces its
7929 dependency on the current stable version of Guile with a dependency on
7930 the legacy version of Guile, @code{guile@@2.0}:
7933 guix build --with-input=guile=guile@@2.0 guix
7936 This is a recursive, deep replacement. So in this example, both
7937 @code{guix} and its dependency @code{guile-json} (which also depends on
7938 @code{guile}) get rebuilt against @code{guile@@2.0}.
7940 This is implemented using the @code{package-input-rewriting} Scheme
7941 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7943 @item --with-graft=@var{package}=@var{replacement}
7944 This is similar to @code{--with-input} but with an important difference:
7945 instead of rebuilding the whole dependency chain, @var{replacement} is
7946 built and then @dfn{grafted} onto the binaries that were initially
7947 referring to @var{package}. @xref{Security Updates}, for more
7948 information on grafts.
7950 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7951 and all its dependencies, replacing references to the version of GnuTLS
7952 they currently refer to:
7955 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7958 This has the advantage of being much faster than rebuilding everything.
7959 But there is a caveat: it works if and only if @var{package} and
7960 @var{replacement} are strictly compatible---for example, if they provide
7961 a library, the application binary interface (ABI) of those libraries
7962 must be compatible. If @var{replacement} is somehow incompatible with
7963 @var{package}, then the resulting package may be unusable. Use with
7966 @item --with-git-url=@var{package}=@var{url}
7967 @cindex Git, using the latest commit
7968 @cindex latest commit, building
7969 Build @var{package} from the latest commit of the @code{master} branch of the
7970 Git repository at @var{url}. Git sub-modules of the repository are fetched,
7973 For example, the following command builds the NumPy Python library against the
7974 latest commit of the master branch of Python itself:
7977 guix build python-numpy \
7978 --with-git-url=python=https://github.com/python/cpython
7981 This option can also be combined with @code{--with-branch} or
7982 @code{--with-commit} (see below).
7984 @cindex continuous integration
7985 Obviously, since it uses the latest commit of the given branch, the result of
7986 such a command varies over time. Nevertheless it is a convenient way to
7987 rebuild entire software stacks against the latest commit of one or more
7988 packages. This is particularly useful in the context of continuous
7991 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
7992 consecutive accesses to the same repository. You may want to clean it up once
7993 in a while to save disk space.
7995 @item --with-branch=@var{package}=@var{branch}
7996 Build @var{package} from the latest commit of @var{branch}. If the
7997 @code{source} field of @var{package} is an origin with the @code{git-fetch}
7998 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
7999 repository URL is taken from that @code{source}. Otherwise you have to use
8000 @code{--with-git-url} to specify the URL of the Git repository.
8002 For instance, the following command builds @code{guile-sqlite3} from the
8003 latest commit of its @code{master} branch, and then builds @code{guix} (which
8004 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8005 specific @code{guile-sqlite3} build:
8008 guix build --with-branch=guile-sqlite3=master cuirass
8011 @item --with-commit=@var{package}=@var{commit}
8012 This is similar to @code{--with-branch}, except that it builds from
8013 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8014 Git commit SHA1 identifier.
8017 @node Additional Build Options
8018 @subsection Additional Build Options
8020 The command-line options presented below are specific to @command{guix
8027 Build quietly, without displaying the build log; this is equivalent to
8028 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8029 (or similar) and can always be retrieved using the @option{--log-file} option.
8031 @item --file=@var{file}
8032 @itemx -f @var{file}
8033 Build the package, derivation, or other file-like object that the code within
8034 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8036 As an example, @var{file} might contain a package definition like this
8037 (@pxref{Defining Packages}):
8040 @verbatiminclude package-hello.scm
8043 @item --expression=@var{expr}
8044 @itemx -e @var{expr}
8045 Build the package or derivation @var{expr} evaluates to.
8047 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8048 guile-1.8)}, which unambiguously designates this specific variant of
8049 version 1.8 of Guile.
8051 Alternatively, @var{expr} may be a G-expression, in which case it is used
8052 as a build program passed to @code{gexp->derivation}
8053 (@pxref{G-Expressions}).
8055 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8056 (@pxref{The Store Monad}). The procedure must return a derivation as a
8057 monadic value, which is then passed through @code{run-with-store}.
8061 Build the source derivations of the packages, rather than the packages
8064 For instance, @code{guix build -S gcc} returns something like
8065 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8068 The returned source tarball is the result of applying any patches and
8069 code snippets specified in the package @code{origin} (@pxref{Defining
8073 Fetch and return the source of @var{package-or-derivation} and all their
8074 dependencies, recursively. This is a handy way to obtain a local copy
8075 of all the source code needed to build @var{packages}, allowing you to
8076 eventually build them even without network access. It is an extension
8077 of the @code{--source} option and can accept one of the following
8078 optional argument values:
8082 This value causes the @code{--sources} option to behave in the same way
8083 as the @code{--source} option.
8086 Build the source derivations of all packages, including any source that
8087 might be listed as @code{inputs}. This is the default value.
8090 $ guix build --sources tzdata
8091 The following derivations will be built:
8092 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8093 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8097 Build the source derivations of all packages, as well of all transitive
8098 inputs to the packages. This can be used e.g.@: to
8099 prefetch package source for later offline building.
8102 $ guix build --sources=transitive tzdata
8103 The following derivations will be built:
8104 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8105 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8106 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8107 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8108 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8109 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8115 @item --system=@var{system}
8116 @itemx -s @var{system}
8117 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8118 the system type of the build host. The @command{guix build} command allows
8119 you to repeat this option several times, in which case it builds for all the
8120 specified systems; other commands ignore extraneous @option{-s} options.
8123 The @code{--system} flag is for @emph{native} compilation and must not
8124 be confused with cross-compilation. See @code{--target} below for
8125 information on cross-compilation.
8128 An example use of this is on Linux-based systems, which can emulate
8129 different personalities. For instance, passing
8130 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8131 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8132 to build packages in a complete 32-bit environment.
8135 Building for an @code{armhf-linux} system is unconditionally enabled on
8136 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8137 allow for this functionality, notably the ThunderX.
8140 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8141 is enabled (@pxref{Virtualization Services,
8142 @code{qemu-binfmt-service-type}}), you can build for any system for
8143 which a QEMU @code{binfmt_misc} handler is installed.
8145 Builds for a system other than that of the machine you are using can
8146 also be offloaded to a remote machine of the right architecture.
8147 @xref{Daemon Offload Setup}, for more information on offloading.
8149 @item --target=@var{triplet}
8150 @cindex cross-compilation
8151 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8152 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8153 configuration triplets,, autoconf, Autoconf}).
8155 @anchor{build-check}
8157 @cindex determinism, checking
8158 @cindex reproducibility, checking
8159 Rebuild @var{package-or-derivation}, which are already available in the
8160 store, and raise an error if the build results are not bit-for-bit
8163 This mechanism allows you to check whether previously installed
8164 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8165 of a package is deterministic. @xref{Invoking guix challenge}, for more
8166 background information and tools.
8168 When used in conjunction with @option{--keep-failed}, the differing
8169 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8170 This makes it easy to look for differences between the two results.
8173 @cindex repairing store items
8174 @cindex corruption, recovering from
8175 Attempt to repair the specified store items, if they are corrupt, by
8176 re-downloading or rebuilding them.
8178 This operation is not atomic and thus restricted to @code{root}.
8182 Return the derivation paths, not the output paths, of the given
8185 @item --root=@var{file}
8186 @itemx -r @var{file}
8187 @cindex GC roots, adding
8188 @cindex garbage collector roots, adding
8189 Make @var{file} a symlink to the result, and register it as a garbage
8192 Consequently, the results of this @command{guix build} invocation are
8193 protected from garbage collection until @var{file} is removed. When
8194 that option is omitted, build results are eligible for garbage
8195 collection as soon as the build completes. @xref{Invoking guix gc}, for
8199 @cindex build logs, access
8200 Return the build log file names or URLs for the given
8201 @var{package-or-derivation}, or raise an error if build logs are
8204 This works regardless of how packages or derivations are specified. For
8205 instance, the following invocations are equivalent:
8208 guix build --log-file `guix build -d guile`
8209 guix build --log-file `guix build guile`
8210 guix build --log-file guile
8211 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8214 If a log is unavailable locally, and unless @code{--no-substitutes} is
8215 passed, the command looks for a corresponding log on one of the
8216 substitute servers (as specified with @code{--substitute-urls}.)
8218 So for instance, imagine you want to see the build log of GDB on MIPS,
8219 but you are actually on an @code{x86_64} machine:
8222 $ guix build --log-file gdb -s mips64el-linux
8223 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8226 You can freely access a huge library of build logs!
8229 @node Debugging Build Failures
8230 @subsection Debugging Build Failures
8232 @cindex build failures, debugging
8233 When defining a new package (@pxref{Defining Packages}), you will
8234 probably find yourself spending some time debugging and tweaking the
8235 build until it succeeds. To do that, you need to operate the build
8236 commands yourself in an environment as close as possible to the one the
8239 To that end, the first thing to do is to use the @option{--keep-failed}
8240 or @option{-K} option of @command{guix build}, which will keep the
8241 failed build tree in @file{/tmp} or whatever directory you specified as
8242 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8244 From there on, you can @command{cd} to the failed build tree and source
8245 the @file{environment-variables} file, which contains all the
8246 environment variable definitions that were in place when the build
8247 failed. So let's say you're debugging a build failure in package
8248 @code{foo}; a typical session would look like this:
8252 @dots{} @i{build fails}
8253 $ cd /tmp/guix-build-foo.drv-0
8254 $ source ./environment-variables
8258 Now, you can invoke commands as if you were the daemon (almost) and
8259 troubleshoot your build process.
8261 Sometimes it happens that, for example, a package's tests pass when you
8262 run them manually but they fail when the daemon runs them. This can
8263 happen because the daemon runs builds in containers where, unlike in our
8264 environment above, network access is missing, @file{/bin/sh} does not
8265 exist, etc. (@pxref{Build Environment Setup}).
8267 In such cases, you may need to run inspect the build process from within
8268 a container similar to the one the build daemon creates:
8273 $ cd /tmp/guix-build-foo.drv-0
8274 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8275 [env]# source ./environment-variables
8279 Here, @command{guix environment -C} creates a container and spawns a new
8280 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8281 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8282 the container, which would may find handy while debugging. The
8283 @option{--no-grafts} option makes sure we get the exact same
8284 environment, with ungrafted packages (@pxref{Security Updates}, for more
8287 To get closer to a container like that used by the build daemon, we can
8288 remove @file{/bin/sh}:
8294 (Don't worry, this is harmless: this is all happening in the throw-away
8295 container created by @command{guix environment}.)
8297 The @command{strace} command is probably not in the search path, but we
8301 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8304 In this way, not only you will have reproduced the environment variables
8305 the daemon uses, you will also be running the build process in a container
8306 similar to the one the daemon uses.
8309 @node Invoking guix edit
8310 @section Invoking @command{guix edit}
8312 @cindex @command{guix edit}
8313 @cindex package definition, editing
8314 So many packages, so many source files! The @command{guix edit} command
8315 facilitates the life of users and packagers by pointing their editor at
8316 the source file containing the definition of the specified packages.
8320 guix edit gcc@@4.9 vim
8324 launches the program specified in the @code{VISUAL} or in the
8325 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8328 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8329 have created your own packages on @code{GUIX_PACKAGE_PATH}
8330 (@pxref{Package Modules}), you will be able to edit the package
8331 recipes. In other cases, you will be able to examine the read-only recipes
8332 for packages currently in the store.
8335 @node Invoking guix download
8336 @section Invoking @command{guix download}
8338 @cindex @command{guix download}
8339 @cindex downloading package sources
8340 When writing a package definition, developers typically need to download
8341 a source tarball, compute its SHA256 hash, and write that
8342 hash in the package definition (@pxref{Defining Packages}). The
8343 @command{guix download} tool helps with this task: it downloads a file
8344 from the given URI, adds it to the store, and prints both its file name
8345 in the store and its SHA256 hash.
8347 The fact that the downloaded file is added to the store saves bandwidth:
8348 when the developer eventually tries to build the newly defined package
8349 with @command{guix build}, the source tarball will not have to be
8350 downloaded again because it is already in the store. It is also a
8351 convenient way to temporarily stash files, which may be deleted
8352 eventually (@pxref{Invoking guix gc}).
8354 The @command{guix download} command supports the same URIs as used in
8355 package definitions. In particular, it supports @code{mirror://} URIs.
8356 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8357 Guile bindings for GnuTLS are available in the user's environment; when
8358 they are not available, an error is raised. @xref{Guile Preparations,
8359 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8360 GnuTLS-Guile}, for more information.
8362 @command{guix download} verifies HTTPS server certificates by loading
8363 the certificates of X.509 authorities from the directory pointed to by
8364 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8365 Certificates}), unless @option{--no-check-certificate} is used.
8367 The following options are available:
8370 @item --format=@var{fmt}
8372 Write the hash in the format specified by @var{fmt}. For more
8373 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8375 @item --no-check-certificate
8376 Do not validate the X.509 certificates of HTTPS servers.
8378 When using this option, you have @emph{absolutely no guarantee} that you
8379 are communicating with the authentic server responsible for the given
8380 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8382 @item --output=@var{file}
8383 @itemx -o @var{file}
8384 Save the downloaded file to @var{file} instead of adding it to the
8388 @node Invoking guix hash
8389 @section Invoking @command{guix hash}
8391 @cindex @command{guix hash}
8392 The @command{guix hash} command computes the SHA256 hash of a file.
8393 It is primarily a convenience tool for anyone contributing to the
8394 distribution: it computes the cryptographic hash of a file, which can be
8395 used in the definition of a package (@pxref{Defining Packages}).
8397 The general syntax is:
8400 guix hash @var{option} @var{file}
8403 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8404 hash of data read from standard input. @command{guix hash} has the
8409 @item --format=@var{fmt}
8411 Write the hash in the format specified by @var{fmt}.
8413 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8414 (@code{hex} and @code{hexadecimal} can be used as well).
8416 If the @option{--format} option is not specified, @command{guix hash}
8417 will output the hash in @code{nix-base32}. This representation is used
8418 in the definitions of packages.
8422 Compute the hash on @var{file} recursively.
8424 In this case, the hash is computed on an archive containing @var{file},
8425 including its children if it is a directory. Some of the metadata of
8426 @var{file} is part of the archive; for instance, when @var{file} is a
8427 regular file, the hash is different depending on whether @var{file} is
8428 executable or not. Metadata such as time stamps has no impact on the
8429 hash (@pxref{Invoking guix archive}).
8430 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8435 When combined with @option{--recursive}, exclude version control system
8436 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8439 As an example, here is how you would compute the hash of a Git checkout,
8440 which is useful when using the @code{git-fetch} method (@pxref{origin
8444 $ git clone http://example.org/foo.git
8450 @node Invoking guix import
8451 @section Invoking @command{guix import}
8453 @cindex importing packages
8454 @cindex package import
8455 @cindex package conversion
8456 @cindex Invoking @command{guix import}
8457 The @command{guix import} command is useful for people who would like to
8458 add a package to the distribution with as little work as
8459 possible---a legitimate demand. The command knows of a few
8460 repositories from which it can ``import'' package metadata. The result
8461 is a package definition, or a template thereof, in the format we know
8462 (@pxref{Defining Packages}).
8464 The general syntax is:
8467 guix import @var{importer} @var{options}@dots{}
8470 @var{importer} specifies the source from which to import package
8471 metadata, and @var{options} specifies a package identifier and other
8472 options specific to @var{importer}. Currently, the available
8477 Import metadata for the given GNU package. This provides a template
8478 for the latest version of that GNU package, including the hash of its
8479 source tarball, and its canonical synopsis and description.
8481 Additional information such as the package dependencies and its
8482 license needs to be figured out manually.
8484 For example, the following command returns a package definition for
8488 guix import gnu hello
8491 Specific command-line options are:
8494 @item --key-download=@var{policy}
8495 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8496 keys when verifying the package signature. @xref{Invoking guix
8497 refresh, @code{--key-download}}.
8502 Import metadata from the @uref{https://pypi.python.org/, Python Package
8503 Index}. Information is taken from the JSON-formatted description
8504 available at @code{pypi.python.org} and usually includes all the relevant
8505 information, including package dependencies. For maximum efficiency, it
8506 is recommended to install the @command{unzip} utility, so that the
8507 importer can unzip Python wheels and gather data from them.
8509 The command below imports metadata for the @code{itsdangerous} Python
8513 guix import pypi itsdangerous
8519 Traverse the dependency graph of the given upstream package recursively
8520 and generate package expressions for all those packages that are not yet
8526 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8527 is taken from the JSON-formatted description available at
8528 @code{rubygems.org} and includes most relevant information, including
8529 runtime dependencies. There are some caveats, however. The metadata
8530 doesn't distinguish between synopses and descriptions, so the same string
8531 is used for both fields. Additionally, the details of non-Ruby
8532 dependencies required to build native extensions is unavailable and left
8533 as an exercise to the packager.
8535 The command below imports metadata for the @code{rails} Ruby package:
8538 guix import gem rails
8544 Traverse the dependency graph of the given upstream package recursively
8545 and generate package expressions for all those packages that are not yet
8551 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8552 Information is taken from the JSON-formatted metadata provided through
8553 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8554 relevant information, such as module dependencies. License information
8555 should be checked closely. If Perl is available in the store, then the
8556 @code{corelist} utility will be used to filter core modules out of the
8557 list of dependencies.
8559 The command command below imports metadata for the @code{Acme::Boolean}
8563 guix import cpan Acme::Boolean
8568 @cindex Bioconductor
8569 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8570 central repository for the @uref{https://r-project.org, GNU@tie{}R
8571 statistical and graphical environment}.
8573 Information is extracted from the @code{DESCRIPTION} file of the package.
8575 The command command below imports metadata for the @code{Cairo}
8579 guix import cran Cairo
8582 When @code{--recursive} is added, the importer will traverse the
8583 dependency graph of the given upstream package recursively and generate
8584 package expressions for all those packages that are not yet in Guix.
8586 When @code{--archive=bioconductor} is added, metadata is imported from
8587 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8588 packages for for the analysis and comprehension of high-throughput
8589 genomic data in bioinformatics.
8591 Information is extracted from the @code{DESCRIPTION} file of a package
8592 published on the web interface of the Bioconductor SVN repository.
8594 The command below imports metadata for the @code{GenomicRanges}
8598 guix import cran --archive=bioconductor GenomicRanges
8604 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8605 comprehensive TeX archive network for TeX packages that are part of the
8606 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8608 Information about the package is obtained through the XML API provided
8609 by CTAN, while the source code is downloaded from the SVN repository of
8610 the Tex Live project. This is done because the CTAN does not keep
8613 The command command below imports metadata for the @code{fontspec}
8617 guix import texlive fontspec
8620 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8621 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8622 tree in the TeX Live SVN repository, but from the specified sibling
8623 directory under the same root.
8625 The command below imports metadata for the @code{ifxetex} package from
8626 CTAN while fetching the sources from the directory
8627 @file{texmf/source/generic}:
8630 guix import texlive --archive=generic ifxetex
8634 @cindex JSON, import
8635 Import package metadata from a local JSON file. Consider the following
8636 example package definition in JSON format:
8642 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8643 "build-system": "gnu",
8644 "home-page": "https://www.gnu.org/software/hello/",
8645 "synopsis": "Hello, GNU world: An example GNU package",
8646 "description": "GNU Hello prints a greeting.",
8647 "license": "GPL-3.0+",
8648 "native-inputs": ["gcc@@6"]
8652 The field names are the same as for the @code{<package>} record
8653 (@xref{Defining Packages}). References to other packages are provided
8654 as JSON lists of quoted package specification strings such as
8655 @code{guile} or @code{guile@@2.0}.
8657 The importer also supports a more explicit source definition using the
8658 common fields for @code{<origin>} records:
8664 "method": "url-fetch",
8665 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8667 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8674 The command below reads metadata from the JSON file @code{hello.json}
8675 and outputs a package expression:
8678 guix import json hello.json
8682 Import metadata from a local copy of the source of the
8683 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8684 relies on the @command{nix-instantiate} command of
8685 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8686 typically written in a mixture of Nix-language and Bash code. This
8687 command only imports the high-level package structure that is written in
8688 the Nix language. It normally includes all the basic fields of a
8691 When importing a GNU package, the synopsis and descriptions are replaced
8692 by their canonical upstream variant.
8694 Usually, you will first need to do:
8697 export NIX_REMOTE=daemon
8701 so that @command{nix-instantiate} does not try to open the Nix database.
8703 As an example, the command below imports the package definition of
8704 LibreOffice (more precisely, it imports the definition of the package
8705 bound to the @code{libreoffice} top-level attribute):
8708 guix import nix ~/path/to/nixpkgs libreoffice
8713 Import metadata from the Haskell community's central package archive
8714 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8715 Cabal files and includes all the relevant information, including package
8718 Specific command-line options are:
8723 Read a Cabal file from standard input.
8724 @item --no-test-dependencies
8726 Do not include dependencies required only by the test suites.
8727 @item --cabal-environment=@var{alist}
8728 @itemx -e @var{alist}
8729 @var{alist} is a Scheme alist defining the environment in which the
8730 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8731 @code{arch}, @code{impl} and a string representing the name of a flag.
8732 The value associated with a flag has to be either the symbol
8733 @code{true} or @code{false}. The value associated with other keys
8734 has to conform to the Cabal file format definition. The default value
8735 associated with the keys @code{os}, @code{arch} and @code{impl} is
8736 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8739 Traverse the dependency graph of the given upstream package recursively
8740 and generate package expressions for all those packages that are not yet
8744 The command below imports metadata for the latest version of the
8745 @code{HTTP} Haskell package without including test dependencies and
8746 specifying the value of the flag @samp{network-uri} as @code{false}:
8749 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8752 A specific package version may optionally be specified by following the
8753 package name by an at-sign and a version number as in the following example:
8756 guix import hackage mtl@@2.1.3.1
8761 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8762 It takes a package name, looks up the package version included in a
8763 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8764 release and uses the @code{hackage} importer to retrieve its metadata.
8765 Note that it is up to you to select an LTS release compatible with the
8766 GHC compiler used by Guix.
8768 Specific command-line options are:
8771 @item --no-test-dependencies
8773 Do not include dependencies required only by the test suites.
8774 @item --lts-version=@var{version}
8775 @itemx -l @var{version}
8776 @var{version} is the desired LTS release version. If omitted the latest
8780 Traverse the dependency graph of the given upstream package recursively
8781 and generate package expressions for all those packages that are not yet
8785 The command below imports metadata for the @code{HTTP} Haskell package
8786 included in the LTS Stackage release version 7.18:
8789 guix import stackage --lts-version=7.18 HTTP
8794 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8795 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8797 Specific command-line options are:
8800 @item --archive=@var{repo}
8801 @itemx -a @var{repo}
8802 @var{repo} identifies the archive repository from which to retrieve the
8803 information. Currently the supported repositories and their identifiers
8807 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8808 identifier. This is the default.
8810 Packages from @code{elpa.gnu.org} are signed with one of the keys
8811 contained in the GnuPG keyring at
8812 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8813 @code{emacs} package (@pxref{Package Installation, ELPA package
8814 signatures,, emacs, The GNU Emacs Manual}).
8817 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
8818 @code{melpa-stable} identifier.
8821 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
8827 Traverse the dependency graph of the given upstream package recursively
8828 and generate package expressions for all those packages that are not yet
8834 Import metadata from the crates.io Rust package repository
8835 @uref{https://crates.io, crates.io}.
8840 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8841 repository used by the OCaml community.
8844 The structure of the @command{guix import} code is modular. It would be
8845 useful to have more importers for other package formats, and your help
8846 is welcome here (@pxref{Contributing}).
8848 @node Invoking guix refresh
8849 @section Invoking @command{guix refresh}
8851 @cindex @command {guix refresh}
8852 The primary audience of the @command{guix refresh} command is developers
8853 of the GNU software distribution. By default, it reports any packages
8854 provided by the distribution that are outdated compared to the latest
8855 upstream version, like this:
8859 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8860 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8863 Alternately, one can specify packages to consider, in which case a
8864 warning is emitted for packages that lack an updater:
8867 $ guix refresh coreutils guile guile-ssh
8868 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8869 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8872 @command{guix refresh} browses the upstream repository of each package and determines
8873 the highest version number of the releases therein. The command
8874 knows how to update specific types of packages: GNU packages, ELPA
8875 packages, etc.---see the documentation for @option{--type} below. There
8876 are many packages, though, for which it lacks a method to determine
8877 whether a new upstream release is available. However, the mechanism is
8878 extensible, so feel free to get in touch with us to add a new method!
8883 Consider the packages specified, and all the packages upon which they depend.
8886 $ guix refresh --recursive coreutils
8887 gnu/packages/acl.scm:35:2: warning: no updater for acl
8888 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8889 gnu/packages/xml.scm:68:2: warning: no updater for expat
8890 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8896 Sometimes the upstream name differs from the package name used in Guix,
8897 and @command{guix refresh} needs a little help. Most updaters honor the
8898 @code{upstream-name} property in package definitions, which can be used
8902 (define-public network-manager
8904 (name "network-manager")
8906 (properties '((upstream-name . "NetworkManager")))))
8909 When passed @code{--update}, it modifies distribution source files to
8910 update the version numbers and source tarball hashes of those package
8911 recipes (@pxref{Defining Packages}). This is achieved by downloading
8912 each package's latest source tarball and its associated OpenPGP
8913 signature, authenticating the downloaded tarball against its signature
8914 using @command{gpg}, and finally computing its hash. When the public
8915 key used to sign the tarball is missing from the user's keyring, an
8916 attempt is made to automatically retrieve it from a public key server;
8917 when this is successful, the key is added to the user's keyring; otherwise,
8918 @command{guix refresh} reports an error.
8920 The following options are supported:
8924 @item --expression=@var{expr}
8925 @itemx -e @var{expr}
8926 Consider the package @var{expr} evaluates to.
8928 This is useful to precisely refer to a package, as in this example:
8931 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8934 This command lists the dependents of the ``final'' libc (essentially all
8939 Update distribution source files (package recipes) in place. This is
8940 usually run from a checkout of the Guix source tree (@pxref{Running
8941 Guix Before It Is Installed}):
8944 $ ./pre-inst-env guix refresh -s non-core -u
8947 @xref{Defining Packages}, for more information on package definitions.
8949 @item --select=[@var{subset}]
8950 @itemx -s @var{subset}
8951 Select all the packages in @var{subset}, one of @code{core} or
8954 The @code{core} subset refers to all the packages at the core of the
8955 distribution---i.e., packages that are used to build ``everything
8956 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8957 changing one of these packages in the distribution entails a rebuild of
8958 all the others. Thus, such updates are an inconvenience to users in
8959 terms of build time or bandwidth used to achieve the upgrade.
8961 The @code{non-core} subset refers to the remaining packages. It is
8962 typically useful in cases where an update of the core packages would be
8965 @item --manifest=@var{file}
8966 @itemx -m @var{file}
8967 Select all the packages from the manifest in @var{file}. This is useful to
8968 check if any packages of the user manifest can be updated.
8970 @item --type=@var{updater}
8971 @itemx -t @var{updater}
8972 Select only packages handled by @var{updater} (may be a comma-separated
8973 list of updaters). Currently, @var{updater} may be one of:
8977 the updater for GNU packages;
8979 the updater for GNOME packages;
8981 the updater for KDE packages;
8983 the updater for X.org packages;
8985 the updater for packages hosted on kernel.org;
8987 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
8989 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
8991 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
8993 the updater for @uref{https://www.cpan.org/, CPAN} packages;
8995 the updater for @uref{https://pypi.python.org, PyPI} packages.
8997 the updater for @uref{https://rubygems.org, RubyGems} packages.
8999 the updater for @uref{https://github.com, GitHub} packages.
9001 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9003 the updater for @uref{https://www.stackage.org, Stackage} packages.
9005 the updater for @uref{https://crates.io, Crates} packages.
9007 the updater for @uref{https://launchpad.net, Launchpad} packages.
9010 For instance, the following command only checks for updates of Emacs
9011 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9014 $ guix refresh --type=elpa,cran
9015 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9016 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9021 In addition, @command{guix refresh} can be passed one or more package
9022 names, as in this example:
9025 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9029 The command above specifically updates the @code{emacs} and
9030 @code{idutils} packages. The @code{--select} option would have no
9031 effect in this case.
9033 When considering whether to upgrade a package, it is sometimes
9034 convenient to know which packages would be affected by the upgrade and
9035 should be checked for compatibility. For this the following option may
9036 be used when passing @command{guix refresh} one or more package names:
9040 @item --list-updaters
9042 List available updaters and exit (see @option{--type} above.)
9044 For each updater, display the fraction of packages it covers; at the
9045 end, display the fraction of packages covered by all these updaters.
9047 @item --list-dependent
9049 List top-level dependent packages that would need to be rebuilt as a
9050 result of upgrading one or more packages.
9052 @xref{Invoking guix graph, the @code{reverse-package} type of
9053 @command{guix graph}}, for information on how to visualize the list of
9054 dependents of a package.
9058 Be aware that the @code{--list-dependent} option only
9059 @emph{approximates} the rebuilds that would be required as a result of
9060 an upgrade. More rebuilds might be required under some circumstances.
9063 $ guix refresh --list-dependent flex
9064 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9065 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9068 The command above lists a set of packages that could be built to check
9069 for compatibility with an upgraded @code{flex} package.
9073 @item --list-transitive
9074 List all the packages which one or more packages depend upon.
9077 $ guix refresh --list-transitive flex
9078 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9079 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{}
9084 The command above lists a set of packages which, when changed, would cause
9085 @code{flex} to be rebuilt.
9087 The following options can be used to customize GnuPG operation:
9091 @item --gpg=@var{command}
9092 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9093 for in @code{$PATH}.
9095 @item --keyring=@var{file}
9096 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9097 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9098 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9099 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9100 information on a tool to manipulate keybox files).
9102 When this option is omitted, @command{guix refresh} uses
9103 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9104 signing keys. OpenPGP signatures are checked against keys from this keyring;
9105 missing keys are downloaded to this keyring as well (see
9106 @option{--key-download} below.)
9108 You can export keys from your default GPG keyring into a keybox file using
9109 commands like this one:
9112 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9115 Likewise, you can fetch keys to a specific keybox file like this:
9118 gpg --no-default-keyring --keyring mykeyring.kbx \
9119 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9122 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9123 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9125 @item --key-download=@var{policy}
9126 Handle missing OpenPGP keys according to @var{policy}, which may be one
9131 Always download missing OpenPGP keys from the key server, and add them
9132 to the user's GnuPG keyring.
9135 Never try to download missing OpenPGP keys. Instead just bail out.
9138 When a package signed with an unknown OpenPGP key is encountered, ask
9139 the user whether to download it or not. This is the default behavior.
9142 @item --key-server=@var{host}
9143 Use @var{host} as the OpenPGP key server when importing a public key.
9147 The @code{github} updater uses the
9148 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9149 releases. When used repeatedly e.g.@: when refreshing all packages,
9150 GitHub will eventually refuse to answer any further API requests. By
9151 default 60 API requests per hour are allowed, and a full refresh on all
9152 GitHub packages in Guix requires more than this. Authentication with
9153 GitHub through the use of an API token alleviates these limits. To use
9154 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9155 token procured from @uref{https://github.com/settings/tokens} or
9159 @node Invoking guix lint
9160 @section Invoking @command{guix lint}
9162 @cindex @command{guix lint}
9163 @cindex package, checking for errors
9164 The @command{guix lint} command is meant to help package developers avoid
9165 common errors and use a consistent style. It runs a number of checks on
9166 a given set of packages in order to find common mistakes in their
9167 definitions. Available @dfn{checkers} include (see
9168 @code{--list-checkers} for a complete list):
9173 Validate certain typographical and stylistic rules about package
9174 descriptions and synopses.
9176 @item inputs-should-be-native
9177 Identify inputs that should most likely be native inputs.
9183 @itemx source-file-name
9184 Probe @code{home-page} and @code{source} URLs and report those that are
9185 invalid. Suggest a @code{mirror://} URL when applicable. If the
9186 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9187 URL. Check that the source file name is meaningful, e.g.@: is not just a
9188 version number or ``git-checkout'', without a declared @code{file-name}
9189 (@pxref{origin Reference}).
9191 @item source-unstable-tarball
9192 Parse the @code{source} URL to determine if a tarball from GitHub is
9193 autogenerated or if it is a release tarball. Unfortunately GitHub's
9194 autogenerated tarballs are sometimes regenerated.
9197 @cindex security vulnerabilities
9198 @cindex CVE, Common Vulnerabilities and Exposures
9199 Report known vulnerabilities found in the Common Vulnerabilities and
9200 Exposures (CVE) databases of the current and past year
9201 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9204 To view information about a particular vulnerability, visit pages such as:
9208 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9210 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9214 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9215 @code{CVE-2015-7554}.
9217 Package developers can specify in package recipes the
9218 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9219 name and version of the package when they differ from the name or version
9220 that Guix uses, as in this example:
9226 ;; CPE calls this package "grub2".
9227 (properties '((cpe-name . "grub2")
9228 (cpe-version . "2.3")))
9231 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9232 Some entries in the CVE database do not specify which version of a
9233 package they apply to, and would thus ``stick around'' forever. Package
9234 developers who found CVE alerts and verified they can be ignored can
9235 declare them as in this example:
9241 ;; These CVEs no longer apply and can be safely ignored.
9242 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9245 "CVE-2011-5244")))))
9249 Warn about obvious source code formatting issues: trailing white space,
9250 use of tabulations, etc.
9253 The general syntax is:
9256 guix lint @var{options} @var{package}@dots{}
9259 If no package is given on the command line, then all packages are checked.
9260 The @var{options} may be zero or more of the following:
9263 @item --list-checkers
9265 List and describe all the available checkers that will be run on packages
9270 Only enable the checkers specified in a comma-separated list using the
9271 names returned by @code{--list-checkers}.
9275 @node Invoking guix size
9276 @section Invoking @command{guix size}
9279 @cindex package size
9281 @cindex @command{guix size}
9282 The @command{guix size} command helps package developers profile the
9283 disk usage of packages. It is easy to overlook the impact of an
9284 additional dependency added to a package, or the impact of using a
9285 single output for a package that could easily be split (@pxref{Packages
9286 with Multiple Outputs}). Such are the typical issues that
9287 @command{guix size} can highlight.
9289 The command can be passed one or more package specifications
9290 such as @code{gcc@@4.8}
9291 or @code{guile:debug}, or a file name in the store. Consider this
9295 $ guix size coreutils
9296 store item total self
9297 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9298 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9299 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9300 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9301 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9302 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9303 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9304 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9309 The store items listed here constitute the @dfn{transitive closure} of
9310 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9311 would be returned by:
9314 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9317 Here the output shows three columns next to store items. The first column,
9318 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9319 the store item---that is, its own size plus the size of all its
9320 dependencies. The next column, labeled ``self'', shows the size of the
9321 item itself. The last column shows the ratio of the size of the item
9322 itself to the space occupied by all the items listed here.
9324 In this example, we see that the closure of Coreutils weighs in at
9325 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9326 libraries. (That libc and GCC's libraries represent a large fraction of
9327 the closure is not a problem @i{per se} because they are always available
9328 on the system anyway.)
9330 When the package(s) passed to @command{guix size} are available in the
9331 store@footnote{More precisely, @command{guix size} looks for the
9332 @emph{ungrafted} variant of the given package(s), as returned by
9333 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9334 for information on grafts.}, @command{guix size} queries the daemon to determine its
9335 dependencies, and measures its size in the store, similar to @command{du
9336 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9339 When the given packages are @emph{not} in the store, @command{guix size}
9340 reports information based on the available substitutes
9341 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9342 store items that are not even on disk, only available remotely.
9344 You can also specify several package names:
9347 $ guix size coreutils grep sed bash
9348 store item total self
9349 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9350 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9351 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9352 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9358 In this example we see that the combination of the four packages takes
9359 102.3@tie{}MiB in total, which is much less than the sum of each closure
9360 since they have a lot of dependencies in common.
9362 The available options are:
9366 @item --substitute-urls=@var{urls}
9367 Use substitute information from @var{urls}.
9368 @xref{client-substitute-urls, the same option for @code{guix build}}.
9370 @item --sort=@var{key}
9371 Sort lines according to @var{key}, one of the following options:
9375 the size of each item (the default);
9377 the total size of the item's closure.
9380 @item --map-file=@var{file}
9381 Write a graphical map of disk usage in PNG format to @var{file}.
9383 For the example above, the map looks like this:
9385 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9386 produced by @command{guix size}}
9388 This option requires that
9389 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9390 installed and visible in Guile's module search path. When that is not
9391 the case, @command{guix size} fails as it tries to load it.
9393 @item --system=@var{system}
9394 @itemx -s @var{system}
9395 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9399 @node Invoking guix graph
9400 @section Invoking @command{guix graph}
9403 @cindex @command{guix graph}
9404 @cindex package dependencies
9405 Packages and their dependencies form a @dfn{graph}, specifically a
9406 directed acyclic graph (DAG). It can quickly become difficult to have a
9407 mental model of the package DAG, so the @command{guix graph} command
9408 provides a visual representation of the DAG. By default,
9409 @command{guix graph} emits a DAG representation in the input format of
9410 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9411 directly to the @command{dot} command of Graphviz. It can also emit an
9412 HTML page with embedded JavaScript code to display a ``chord diagram''
9413 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9414 emit Cypher queries to construct a graph in a graph database supporting
9415 the @uref{https://www.opencypher.org/, openCypher} query language.
9416 The general syntax is:
9419 guix graph @var{options} @var{package}@dots{}
9422 For example, the following command generates a PDF file representing the
9423 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9427 guix graph coreutils | dot -Tpdf > dag.pdf
9430 The output looks like this:
9432 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9434 Nice little graph, no?
9436 But there is more than one graph! The one above is concise: it is the
9437 graph of package objects, omitting implicit inputs such as GCC, libc,
9438 grep, etc. It is often useful to have such a concise graph, but
9439 sometimes one may want to see more details. @command{guix graph} supports
9440 several types of graphs, allowing you to choose the level of detail:
9444 This is the default type used in the example above. It shows the DAG of
9445 package objects, excluding implicit dependencies. It is concise, but
9446 filters out many details.
9448 @item reverse-package
9449 This shows the @emph{reverse} DAG of packages. For example:
9452 guix graph --type=reverse-package ocaml
9455 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9456 you are also interested in cases where OCaml is an implicit dependency, see
9457 @code{reverse-bag} below.)
9459 Note that for core packages this can yield huge graphs. If all you want
9460 is to know the number of packages that depend on a given package, use
9461 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9462 @option{--list-dependent}}).
9465 This is the package DAG, @emph{including} implicit inputs.
9467 For instance, the following command:
9470 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9473 ...@: yields this bigger graph:
9475 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9477 At the bottom of the graph, we see all the implicit inputs of
9478 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9480 Now, note that the dependencies of these implicit inputs---that is, the
9481 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9482 here, for conciseness.
9485 Similar to @code{bag-emerged}, but this time including all the bootstrap
9488 @item bag-with-origins
9489 Similar to @code{bag}, but also showing origins and their dependencies.
9492 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9493 it also takes implicit dependencies into account. For example:
9496 guix graph -t reverse-bag dune
9500 ...@: yields the graph of all packages that depend on Dune, directly or
9501 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9502 @i{via} @code{dune-build-system}, this shows a large number of packages,
9503 whereas @code{reverse-package} would show very few if any.
9506 This is the most detailed representation: It shows the DAG of
9507 derivations (@pxref{Derivations}) and plain store items. Compared to
9508 the above representation, many additional nodes are visible, including
9509 build scripts, patches, Guile modules, etc.
9511 For this type of graph, it is also possible to pass a @file{.drv} file
9512 name instead of a package name, as in:
9515 guix graph -t derivation `guix system build -d my-config.scm`
9519 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9520 For example, the following command shows the graph for the package
9521 module that defines the @code{guile} package:
9524 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9528 All the types above correspond to @emph{build-time dependencies}. The
9529 following graph type represents the @emph{run-time dependencies}:
9533 This is the graph of @dfn{references} of a package output, as returned
9534 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9536 If the given package output is not available in the store, @command{guix
9537 graph} attempts to obtain dependency information from substitutes.
9539 Here you can also pass a store file name instead of a package name. For
9540 example, the command below produces the reference graph of your profile
9541 (which can be big!):
9544 guix graph -t references `readlink -f ~/.guix-profile`
9548 This is the graph of the @dfn{referrers} of a store item, as returned by
9549 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9551 This relies exclusively on local information from your store. For
9552 instance, let us suppose that the current Inkscape is available in 10
9553 profiles on your machine; @command{guix graph -t referrers inkscape}
9554 will show a graph rooted at Inkscape and with those 10 profiles linked
9557 It can help determine what is preventing a store item from being garbage
9562 The available options are the following:
9565 @item --type=@var{type}
9566 @itemx -t @var{type}
9567 Produce a graph output of @var{type}, where @var{type} must be one of
9568 the values listed above.
9571 List the supported graph types.
9573 @item --backend=@var{backend}
9574 @itemx -b @var{backend}
9575 Produce a graph using the selected @var{backend}.
9577 @item --list-backends
9578 List the supported graph backends.
9580 Currently, the available backends are Graphviz and d3.js.
9582 @item --expression=@var{expr}
9583 @itemx -e @var{expr}
9584 Consider the package @var{expr} evaluates to.
9586 This is useful to precisely refer to a package, as in this example:
9589 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9592 @item --system=@var{system}
9593 @itemx -s @var{system}
9594 Display the graph for @var{system}---e.g., @code{i686-linux}.
9596 The package dependency graph is largely architecture-independent, but there
9597 are some architecture-dependent bits that this option allows you to visualize.
9602 @node Invoking guix publish
9603 @section Invoking @command{guix publish}
9605 @cindex @command{guix publish}
9606 The purpose of @command{guix publish} is to enable users to easily share
9607 their store with others, who can then use it as a substitute server
9608 (@pxref{Substitutes}).
9610 When @command{guix publish} runs, it spawns an HTTP server which allows
9611 anyone with network access to obtain substitutes from it. This means
9612 that any machine running Guix can also act as if it were a build farm,
9613 since the HTTP interface is compatible with Hydra, the software behind
9614 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9616 For security, each substitute is signed, allowing recipients to check
9617 their authenticity and integrity (@pxref{Substitutes}). Because
9618 @command{guix publish} uses the signing key of the system, which is only
9619 readable by the system administrator, it must be started as root; the
9620 @code{--user} option makes it drop root privileges early on.
9622 The signing key pair must be generated before @command{guix publish} is
9623 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9626 The general syntax is:
9629 guix publish @var{options}@dots{}
9632 Running @command{guix publish} without any additional arguments will
9633 spawn an HTTP server on port 8080:
9639 Once a publishing server has been authorized (@pxref{Invoking guix
9640 archive}), the daemon may download substitutes from it:
9643 guix-daemon --substitute-urls=http://example.org:8080
9646 By default, @command{guix publish} compresses archives on the fly as it
9647 serves them. This ``on-the-fly'' mode is convenient in that it requires
9648 no setup and is immediately available. However, when serving lots of
9649 clients, we recommend using the @option{--cache} option, which enables
9650 caching of the archives before they are sent to clients---see below for
9651 details. The @command{guix weather} command provides a handy way to
9652 check what a server provides (@pxref{Invoking guix weather}).
9654 As a bonus, @command{guix publish} also serves as a content-addressed
9655 mirror for source files referenced in @code{origin} records
9656 (@pxref{origin Reference}). For instance, assuming @command{guix
9657 publish} is running on @code{example.org}, the following URL returns the
9658 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9659 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9662 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9665 Obviously, these URLs only work for files that are in the store; in
9666 other cases, they return 404 (``Not Found'').
9668 @cindex build logs, publication
9669 Build logs are available from @code{/log} URLs like:
9672 http://example.org/log/gwspk@dots{}-guile-2.2.3
9676 When @command{guix-daemon} is configured to save compressed build logs,
9677 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9678 URLs return the compressed log as-is, with an appropriate
9679 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9680 running @command{guix-daemon} with @code{--log-compression=gzip} since
9681 Web browsers can automatically decompress it, which is not the case with
9684 The following options are available:
9687 @item --port=@var{port}
9688 @itemx -p @var{port}
9689 Listen for HTTP requests on @var{port}.
9691 @item --listen=@var{host}
9692 Listen on the network interface for @var{host}. The default is to
9693 accept connections from any interface.
9695 @item --user=@var{user}
9696 @itemx -u @var{user}
9697 Change privileges to @var{user} as soon as possible---i.e., once the
9698 server socket is open and the signing key has been read.
9700 @item --compression[=@var{method}[:@var{level}]]
9701 @itemx -C [@var{method}[:@var{level}]]
9702 Compress data using the given @var{method} and @var{level}. @var{method} is
9703 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
9706 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
9707 to different compression levels: 1 is the fastest, and 9 is the best
9708 (CPU-intensive). The default is 3.
9710 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
9711 increase in CPU usage; see
9712 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
9715 Unless @option{--cache} is used, compression occurs on the fly and
9716 the compressed streams are not
9717 cached. Thus, to reduce load on the machine that runs @command{guix
9718 publish}, it may be a good idea to choose a low compression level, to
9719 run @command{guix publish} behind a caching proxy, or to use
9720 @option{--cache}. Using @option{--cache} has the advantage that it
9721 allows @command{guix publish} to add @code{Content-Length} HTTP header
9724 This option can be repeated, in which case every substitute gets compressed
9725 using all the selected methods, and all of them are advertised. This is
9726 useful when users may not support all the compression methods: they can select
9727 the one they support.
9729 @item --cache=@var{directory}
9730 @itemx -c @var{directory}
9731 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9732 and only serve archives that are in cache.
9734 When this option is omitted, archives and meta-data are created
9735 on-the-fly. This can reduce the available bandwidth, especially when
9736 compression is enabled, since this may become CPU-bound. Another
9737 drawback of the default mode is that the length of archives is not known
9738 in advance, so @command{guix publish} does not add a
9739 @code{Content-Length} HTTP header to its responses, which in turn
9740 prevents clients from knowing the amount of data being downloaded.
9742 Conversely, when @option{--cache} is used, the first request for a store
9743 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9744 background process to @dfn{bake} the archive---computing its
9745 @code{.narinfo} and compressing the archive, if needed. Once the
9746 archive is cached in @var{directory}, subsequent requests succeed and
9747 are served directly from the cache, which guarantees that clients get
9748 the best possible bandwidth.
9750 The ``baking'' process is performed by worker threads. By default, one
9751 thread per CPU core is created, but this can be customized. See
9752 @option{--workers} below.
9754 When @option{--ttl} is used, cached entries are automatically deleted
9755 when they have expired.
9757 @item --workers=@var{N}
9758 When @option{--cache} is used, request the allocation of @var{N} worker
9759 threads to ``bake'' archives.
9761 @item --ttl=@var{ttl}
9762 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9763 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9764 days, @code{1m} means 1 month, and so on.
9766 This allows the user's Guix to keep substitute information in cache for
9767 @var{ttl}. However, note that @code{guix publish} does not itself
9768 guarantee that the store items it provides will indeed remain available
9769 for as long as @var{ttl}.
9771 Additionally, when @option{--cache} is used, cached entries that have
9772 not been accessed for @var{ttl} and that no longer have a corresponding
9773 item in the store, may be deleted.
9775 @item --nar-path=@var{path}
9776 Use @var{path} as the prefix for the URLs of ``nar'' files
9777 (@pxref{Invoking guix archive, normalized archives}).
9779 By default, nars are served at a URL such as
9780 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9781 change the @code{/nar} part to @var{path}.
9783 @item --public-key=@var{file}
9784 @itemx --private-key=@var{file}
9785 Use the specific @var{file}s as the public/private key pair used to sign
9786 the store items being published.
9788 The files must correspond to the same key pair (the private key is used
9789 for signing and the public key is merely advertised in the signature
9790 metadata). They must contain keys in the canonical s-expression format
9791 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9792 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9793 @file{/etc/guix/signing-key.sec} are used.
9795 @item --repl[=@var{port}]
9796 @itemx -r [@var{port}]
9797 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9798 Reference Manual}) on @var{port} (37146 by default). This is used
9799 primarily for debugging a running @command{guix publish} server.
9802 Enabling @command{guix publish} on Guix System is a one-liner: just
9803 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9804 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9805 @code{guix-publish-service-type}}).
9807 If you are instead running Guix on a ``foreign distro'', follow these
9812 If your host distro uses the systemd init system:
9815 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9816 /etc/systemd/system/
9817 # systemctl start guix-publish && systemctl enable guix-publish
9821 If your host distro uses the Upstart init system:
9824 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9825 # start guix-publish
9829 Otherwise, proceed similarly with your distro's init system.
9832 @node Invoking guix challenge
9833 @section Invoking @command{guix challenge}
9835 @cindex reproducible builds
9836 @cindex verifiable builds
9837 @cindex @command{guix challenge}
9839 Do the binaries provided by this server really correspond to the source
9840 code it claims to build? Is a package build process deterministic?
9841 These are the questions the @command{guix challenge} command attempts to
9844 The former is obviously an important question: Before using a substitute
9845 server (@pxref{Substitutes}), one had better @emph{verify} that it
9846 provides the right binaries, and thus @emph{challenge} it. The latter
9847 is what enables the former: If package builds are deterministic, then
9848 independent builds of the package should yield the exact same result,
9849 bit for bit; if a server provides a binary different from the one
9850 obtained locally, it may be either corrupt or malicious.
9852 We know that the hash that shows up in @file{/gnu/store} file names is
9853 the hash of all the inputs of the process that built the file or
9854 directory---compilers, libraries, build scripts,
9855 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9856 one store file name should map to exactly one build output.
9857 @command{guix challenge} checks whether there is, indeed, a single
9858 mapping by comparing the build outputs of several independent builds of
9859 any given store item.
9861 The command output looks like this:
9864 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9865 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9866 updating list of substitutes from 'https://guix.example.org'... 100.0%
9867 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9868 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9869 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9870 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9871 /gnu/store/@dots{}-git-2.5.0 contents differ:
9872 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9873 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9874 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9875 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9876 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9877 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9878 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9882 6,406 store items were analyzed:
9883 - 4,749 (74.1%) were identical
9884 - 525 (8.2%) differed
9885 - 1,132 (17.7%) were inconclusive
9889 In this example, @command{guix challenge} first scans the store to
9890 determine the set of locally-built derivations---as opposed to store
9891 items that were downloaded from a substitute server---and then queries
9892 all the substitute servers. It then reports those store items for which
9893 the servers obtained a result different from the local build.
9895 @cindex non-determinism, in package builds
9896 As an example, @code{guix.example.org} always gets a different answer.
9897 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9898 case of Git. This might indicate that the build process of Git is
9899 non-deterministic, meaning that its output varies as a function of
9900 various things that Guix does not fully control, in spite of building
9901 packages in isolated environments (@pxref{Features}). Most common
9902 sources of non-determinism include the addition of timestamps in build
9903 results, the inclusion of random numbers, and directory listings sorted
9904 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9907 To find out what is wrong with this Git binary, we can do something along
9908 these lines (@pxref{Invoking guix archive}):
9911 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9912 | guix archive -x /tmp/git
9913 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9916 This command shows the difference between the files resulting from the
9917 local build, and the files resulting from the build on
9918 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9919 diffutils, Comparing and Merging Files}). The @command{diff} command
9920 works great for text files. When binary files differ, a better option
9921 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9922 visualize differences for all kinds of files.
9924 Once you have done that work, you can tell whether the differences are due
9925 to a non-deterministic build process or to a malicious server. We try
9926 hard to remove sources of non-determinism in packages to make it easier
9927 to verify substitutes, but of course, this is a process that
9928 involves not just Guix, but a large part of the free software community.
9929 In the meantime, @command{guix challenge} is one tool to help address
9932 If you are writing packages for Guix, you are encouraged to check
9933 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9934 same build result as you did with:
9937 $ guix challenge @var{package}
9941 where @var{package} is a package specification such as
9942 @code{guile@@2.0} or @code{glibc:debug}.
9944 The general syntax is:
9947 guix challenge @var{options} [@var{packages}@dots{}]
9950 When a difference is found between the hash of a locally-built item and
9951 that of a server-provided substitute, or among substitutes provided by
9952 different servers, the command displays it as in the example above and
9953 its exit code is 2 (other non-zero exit codes denote other kinds of
9956 The one option that matters is:
9960 @item --substitute-urls=@var{urls}
9961 Consider @var{urls} the whitespace-separated list of substitute source
9966 Show details about matches (identical contents) in addition to
9967 information about mismatches.
9971 @node Invoking guix copy
9972 @section Invoking @command{guix copy}
9974 @cindex copy, of store items, over SSH
9975 @cindex SSH, copy of store items
9976 @cindex sharing store items across machines
9977 @cindex transferring store items across machines
9978 The @command{guix copy} command copies items from the store of one
9979 machine to that of another machine over a secure shell (SSH)
9980 connection@footnote{This command is available only when Guile-SSH was
9981 found. @xref{Requirements}, for details.}. For example, the following
9982 command copies the @code{coreutils} package, the user's profile, and all
9983 their dependencies over to @var{host}, logged in as @var{user}:
9986 guix copy --to=@var{user}@@@var{host} \
9987 coreutils `readlink -f ~/.guix-profile`
9990 If some of the items to be copied are already present on @var{host},
9991 they are not actually sent.
9993 The command below retrieves @code{libreoffice} and @code{gimp} from
9994 @var{host}, assuming they are available there:
9997 guix copy --from=@var{host} libreoffice gimp
10000 The SSH connection is established using the Guile-SSH client, which is
10001 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10002 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10004 The key used to sign items that are sent must be accepted by the remote
10005 machine. Likewise, the key used by the remote machine to sign items you
10006 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10007 own daemon. @xref{Invoking guix archive}, for more information about
10008 store item authentication.
10010 The general syntax is:
10013 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10016 You must always specify one of the following options:
10019 @item --to=@var{spec}
10020 @itemx --from=@var{spec}
10021 Specify the host to send to or receive from. @var{spec} must be an SSH
10022 spec such as @code{example.org}, @code{charlie@@example.org}, or
10023 @code{charlie@@example.org:2222}.
10026 The @var{items} can be either package names, such as @code{gimp}, or
10027 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10029 When specifying the name of a package to send, it is first built if
10030 needed, unless @option{--dry-run} was specified. Common build options
10031 are supported (@pxref{Common Build Options}).
10034 @node Invoking guix container
10035 @section Invoking @command{guix container}
10037 @cindex @command{guix container}
10039 As of version @value{VERSION}, this tool is experimental. The interface
10040 is subject to radical change in the future.
10043 The purpose of @command{guix container} is to manipulate processes
10044 running within an isolated environment, commonly known as a
10045 ``container'', typically created by the @command{guix environment}
10046 (@pxref{Invoking guix environment}) and @command{guix system container}
10047 (@pxref{Invoking guix system}) commands.
10049 The general syntax is:
10052 guix container @var{action} @var{options}@dots{}
10055 @var{action} specifies the operation to perform with a container, and
10056 @var{options} specifies the context-specific arguments for the action.
10058 The following actions are available:
10062 Execute a command within the context of a running container.
10067 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10070 @var{pid} specifies the process ID of the running container.
10071 @var{program} specifies an executable file name within the root file
10072 system of the container. @var{arguments} are the additional options that
10073 will be passed to @var{program}.
10075 The following command launches an interactive login shell inside a
10076 Guix system container, started by @command{guix system container}, and whose
10077 process ID is 9001:
10080 guix container exec 9001 /run/current-system/profile/bin/bash --login
10083 Note that the @var{pid} cannot be the parent process of a container. It
10084 must be PID 1 of the container or one of its child processes.
10088 @node Invoking guix weather
10089 @section Invoking @command{guix weather}
10091 Occasionally you're grumpy because substitutes are lacking and you end
10092 up building packages by yourself (@pxref{Substitutes}). The
10093 @command{guix weather} command reports on substitute availability on the
10094 specified servers so you can have an idea of whether you'll be grumpy
10095 today. It can sometimes be useful info as a user, but it is primarily
10096 useful to people running @command{guix publish} (@pxref{Invoking guix
10099 @cindex statistics, for substitutes
10100 @cindex availability of substitutes
10101 @cindex substitute availability
10102 @cindex weather, substitute availability
10103 Here's a sample run:
10106 $ guix weather --substitute-urls=https://guix.example.org
10107 computing 5,872 package derivations for x86_64-linux...
10108 looking for 6,128 store items on https://guix.example.org..
10109 updating list of substitutes from 'https://guix.example.org'... 100.0%
10110 https://guix.example.org
10111 43.4% substitutes available (2,658 out of 6,128)
10112 7,032.5 MiB of nars (compressed)
10113 19,824.2 MiB on disk (uncompressed)
10114 0.030 seconds per request (182.9 seconds in total)
10115 33.5 requests per second
10117 9.8% (342 out of 3,470) of the missing items are queued
10119 x86_64-linux: 518 (59.7%)
10120 i686-linux: 221 (25.5%)
10121 aarch64-linux: 128 (14.8%)
10122 build rate: 23.41 builds per hour
10123 x86_64-linux: 11.16 builds per hour
10124 i686-linux: 6.03 builds per hour
10125 aarch64-linux: 6.41 builds per hour
10128 @cindex continuous integration, statistics
10129 As you can see, it reports the fraction of all the packages for which
10130 substitutes are available on the server---regardless of whether
10131 substitutes are enabled, and regardless of whether this server's signing
10132 key is authorized. It also reports the size of the compressed archives
10133 (``nars'') provided by the server, the size the corresponding store
10134 items occupy in the store (assuming deduplication is turned off), and
10135 the server's throughput. The second part gives continuous integration
10136 (CI) statistics, if the server supports it. In addition, using the
10137 @option{--coverage} option, @command{guix weather} can list ``important''
10138 package substitutes missing on the server (see below).
10140 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10141 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10142 challenge}, it ignores signatures on those substitutes, which is
10143 innocuous since the command only gathers statistics and cannot install
10146 The general syntax is:
10149 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10152 When @var{packages} is omitted, @command{guix weather} checks the availability
10153 of substitutes for @emph{all} the packages, or for those specified with
10154 @option{--manifest}; otherwise it only considers the specified packages. It
10155 is also possible to query specific system types with @option{--system}. The
10156 available options are listed below.
10159 @item --substitute-urls=@var{urls}
10160 @var{urls} is the space-separated list of substitute server URLs to
10161 query. When this option is omitted, the default set of substitute
10162 servers is queried.
10164 @item --system=@var{system}
10165 @itemx -s @var{system}
10166 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10167 option can be repeated, in which case @command{guix weather} will query
10168 substitutes for several system types.
10170 @item --manifest=@var{file}
10171 Instead of querying substitutes for all the packages, only ask for those
10172 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10173 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10176 @item --coverage[=@var{count}]
10177 @itemx -c [@var{count}]
10178 Report on substitute coverage for packages: list packages with at least
10179 @var{count} dependents (zero by default) for which substitutes are
10180 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10181 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10182 @var{b} usually lacks substitutes as well. The result looks like this:
10185 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10186 computing 8,983 package derivations for x86_64-linux...
10187 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10188 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10189 @value{SUBSTITUTE-URL}
10190 64.7% substitutes available (6,047 out of 9,343)
10192 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10193 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10194 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10195 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10199 What this example shows is that @code{kcoreaddons} and presumably the 58
10200 packages that depend on it have no substitutes at @code{ci.guix.info};
10201 likewise for @code{qgpgme} and the 46 packages that depend on it.
10203 If you are a Guix developer, or if you are taking care of this build farm,
10204 you'll probably want to have a closer look at these packages: they may simply
10208 @node Invoking guix processes
10209 @section Invoking @command{guix processes}
10211 The @command{guix processes} command can be useful to developers and system
10212 administrators, especially on multi-user machines and on build farms: it lists
10213 the current sessions (connections to the daemon), as well as information about
10214 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10215 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10216 listed.}. Here's an example of the information it returns:
10219 $ sudo guix processes
10222 ClientCommand: guix environment --ad-hoc python
10226 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10230 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10231 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10232 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10233 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10234 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10235 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10236 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10239 In this example we see that @command{guix-daemon} has three clients:
10240 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10241 integration tool; their process identifier (PID) is given by the
10242 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10243 @command{guix-daemon} sub-process of this particular session.
10245 The @code{LockHeld} fields show which store items are currently locked by this
10246 session, which corresponds to store items being built or substituted (the
10247 @code{LockHeld} field is not displayed when @command{guix processes} is not
10248 running as root.) Last, by looking at the @code{ChildProcess} field, we
10249 understand that these three builds are being offloaded (@pxref{Daemon Offload
10252 The output is in Recutils format so we can use the handy @command{recsel}
10253 command to select sessions of interest (@pxref{Selection Expressions,,,
10254 recutils, GNU recutils manual}). As an example, the command shows the command
10255 line and PID of the client that triggered the build of a Perl package:
10258 $ sudo guix processes | \
10259 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10261 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10265 @node System Configuration
10266 @chapter System Configuration
10268 @cindex system configuration
10269 Guix System supports a consistent whole-system configuration
10270 mechanism. By that we mean that all aspects of the global system
10271 configuration---such as the available system services, timezone and
10272 locale settings, user accounts---are declared in a single place. Such
10273 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10275 One of the advantages of putting all the system configuration under the
10276 control of Guix is that it supports transactional system upgrades, and
10277 makes it possible to roll back to a previous system instantiation,
10278 should something go wrong with the new one (@pxref{Features}). Another
10279 advantage is that it makes it easy to replicate the exact same configuration
10280 across different machines, or at different points in time, without
10281 having to resort to additional administration tools layered on top of
10282 the own tools of the system.
10283 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10285 This section describes this mechanism. First we focus on the system
10286 administrator's viewpoint---explaining how the system is configured and
10287 instantiated. Then we show how this mechanism can be extended, for
10288 instance to support new system services.
10291 * Using the Configuration System:: Customizing your GNU system.
10292 * operating-system Reference:: Detail of operating-system declarations.
10293 * File Systems:: Configuring file system mounts.
10294 * Mapped Devices:: Block device extra processing.
10295 * User Accounts:: Specifying user accounts.
10296 * Keyboard Layout:: How the system interprets key strokes.
10297 * Locales:: Language and cultural convention settings.
10298 * Services:: Specifying system services.
10299 * Setuid Programs:: Programs running with root privileges.
10300 * X.509 Certificates:: Authenticating HTTPS servers.
10301 * Name Service Switch:: Configuring libc's name service switch.
10302 * Initial RAM Disk:: Linux-Libre bootstrapping.
10303 * Bootloader Configuration:: Configuring the boot loader.
10304 * Invoking guix system:: Instantiating a system configuration.
10305 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10306 * Defining Services:: Adding new service definitions.
10309 @node Using the Configuration System
10310 @section Using the Configuration System
10312 The operating system is configured by providing an
10313 @code{operating-system} declaration in a file that can then be passed to
10314 the @command{guix system} command (@pxref{Invoking guix system}). A
10315 simple setup, with the default system services, the default Linux-Libre
10316 kernel, initial RAM disk, and boot loader looks like this:
10318 @findex operating-system
10320 @include os-config-bare-bones.texi
10323 This example should be self-describing. Some of the fields defined
10324 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10325 Others, such as @code{packages} and @code{services}, can be omitted, in
10326 which case they get a default value.
10328 Below we discuss the effect of some of the most important fields
10329 (@pxref{operating-system Reference}, for details about all the available
10330 fields), and how to @dfn{instantiate} the operating system using
10331 @command{guix system}.
10333 @unnumberedsubsec Bootloader
10335 @cindex legacy boot, on Intel machines
10336 @cindex BIOS boot, on Intel machines
10339 The @code{bootloader} field describes the method that will be used to boot
10340 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10341 mode, as in the example above. However, more recent machines rely instead on
10342 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10343 the @code{bootloader} field should contain something along these lines:
10346 (bootloader-configuration
10347 (bootloader grub-efi-bootloader)
10348 (target "/boot/efi"))
10351 @xref{Bootloader Configuration}, for more information on the available
10352 configuration options.
10354 @unnumberedsubsec Globally-Visible Packages
10356 @vindex %base-packages
10357 The @code{packages} field lists packages that will be globally visible
10358 on the system, for all user accounts---i.e., in every user's @code{PATH}
10359 environment variable---in addition to the per-user profiles
10360 (@pxref{Invoking guix package}). The @code{%base-packages} variable
10361 provides all the tools one would expect for basic user and administrator
10362 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10363 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10364 etc. The example above adds GNU@tie{}Screen to those,
10365 taken from the @code{(gnu packages screen)}
10366 module (@pxref{Package Modules}). The
10367 @code{(list package output)} syntax can be used to add a specific output
10371 (use-modules (gnu packages))
10372 (use-modules (gnu packages dns))
10376 (packages (cons (list bind "utils")
10380 @findex specification->package
10381 Referring to packages by variable name, like @code{bind} above, has
10382 the advantage of being unambiguous; it also allows typos and such to be
10383 diagnosed right away as ``unbound variables''. The downside is that one
10384 needs to know which module defines which package, and to augment the
10385 @code{use-package-modules} line accordingly. To avoid that, one can use
10386 the @code{specification->package} procedure of the @code{(gnu packages)}
10387 module, which returns the best package for a given name or name and
10391 (use-modules (gnu packages))
10395 (packages (append (map specification->package
10396 '("tcpdump" "htop" "gnupg@@2.0"))
10400 @unnumberedsubsec System Services
10403 @vindex %base-services
10404 The @code{services} field lists @dfn{system services} to be made
10405 available when the system starts (@pxref{Services}).
10406 The @code{operating-system} declaration above specifies that, in
10407 addition to the basic services, we want the OpenSSH secure shell
10408 daemon listening on port 2222 (@pxref{Networking Services,
10409 @code{openssh-service-type}}). Under the hood,
10410 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10411 right command-line options, possibly with supporting configuration files
10412 generated as needed (@pxref{Defining Services}).
10414 @cindex customization, of services
10415 @findex modify-services
10416 Occasionally, instead of using the base services as is, you will want to
10417 customize them. To do this, use @code{modify-services} (@pxref{Service
10418 Reference, @code{modify-services}}) to modify the list.
10420 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10421 (the console log-in) in the @code{%base-services} list (@pxref{Base
10422 Services, @code{%base-services}}). To do that, you can write the
10423 following in your operating system declaration:
10426 (define %my-services
10427 ;; My very own list of services.
10428 (modify-services %base-services
10429 (guix-service-type config =>
10430 (guix-configuration
10432 (use-substitutes? #f)
10433 (extra-options '("--gc-keep-derivations"))))
10434 (mingetty-service-type config =>
10435 (mingetty-configuration
10436 (inherit config)))))
10440 (services %my-services))
10443 This changes the configuration---i.e., the service parameters---of the
10444 @code{guix-service-type} instance, and that of all the
10445 @code{mingetty-service-type} instances in the @code{%base-services} list.
10446 Observe how this is accomplished: first, we arrange for the original
10447 configuration to be bound to the identifier @code{config} in the
10448 @var{body}, and then we write the @var{body} so that it evaluates to the
10449 desired configuration. In particular, notice how we use @code{inherit}
10450 to create a new configuration which has the same values as the old
10451 configuration, but with a few modifications.
10453 @cindex encrypted disk
10454 The configuration for a typical ``desktop'' usage, with an encrypted
10455 root partition, the X11 display
10456 server, GNOME and Xfce (users can choose which of these desktop
10457 environments to use at the log-in screen by pressing @kbd{F1}), network
10458 management, power management, and more, would look like this:
10461 @include os-config-desktop.texi
10464 A graphical system with a choice of lightweight window managers
10465 instead of full-blown desktop environments would look like this:
10468 @include os-config-lightweight-desktop.texi
10471 This example refers to the @file{/boot/efi} file system by its UUID,
10472 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10473 as returned by the @command{blkid} command.
10475 @xref{Desktop Services}, for the exact list of services provided by
10476 @code{%desktop-services}. @xref{X.509 Certificates}, for background
10477 information about the @code{nss-certs} package that is used here.
10479 Again, @code{%desktop-services} is just a list of service objects. If
10480 you want to remove services from there, you can do so using the
10481 procedures for list filtering (@pxref{SRFI-1 Filtering and
10482 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10483 following expression returns a list that contains all the services in
10484 @code{%desktop-services} minus the Avahi service:
10487 (remove (lambda (service)
10488 (eq? (service-kind service) avahi-service-type))
10492 @unnumberedsubsec Instantiating the System
10494 Assuming the @code{operating-system} declaration
10495 is stored in the @file{my-system-config.scm}
10496 file, the @command{guix system reconfigure my-system-config.scm} command
10497 instantiates that configuration, and makes it the default GRUB boot
10498 entry (@pxref{Invoking guix system}).
10500 The normal way to change the system configuration is by updating this
10501 file and re-running @command{guix system reconfigure}. One should never
10502 have to touch files in @file{/etc} or to run commands that modify the
10503 system state such as @command{useradd} or @command{grub-install}. In
10504 fact, you must avoid that since that would not only void your warranty
10505 but also prevent you from rolling back to previous versions of your
10506 system, should you ever need to.
10508 @cindex roll-back, of the operating system
10509 Speaking of roll-back, each time you run @command{guix system
10510 reconfigure}, a new @dfn{generation} of the system is created---without
10511 modifying or deleting previous generations. Old system generations get
10512 an entry in the bootloader boot menu, allowing you to boot them in case
10513 something went wrong with the latest generation. Reassuring, no? The
10514 @command{guix system list-generations} command lists the system
10515 generations available on disk. It is also possible to roll back the
10516 system via the commands @command{guix system roll-back} and
10517 @command{guix system switch-generation}.
10519 Although the @command{guix system reconfigure} command will not modify
10520 previous generations, you must take care when the current generation is not
10521 the latest (e.g., after invoking @command{guix system roll-back}), since
10522 the operation might overwrite a later generation (@pxref{Invoking guix
10525 @unnumberedsubsec The Programming Interface
10527 At the Scheme level, the bulk of an @code{operating-system} declaration
10528 is instantiated with the following monadic procedure (@pxref{The Store
10531 @deffn {Monadic Procedure} operating-system-derivation os
10532 Return a derivation that builds @var{os}, an @code{operating-system}
10533 object (@pxref{Derivations}).
10535 The output of the derivation is a single directory that refers to all
10536 the packages, configuration files, and other supporting files needed to
10537 instantiate @var{os}.
10540 This procedure is provided by the @code{(gnu system)} module. Along
10541 with @code{(gnu services)} (@pxref{Services}), this module contains the
10542 guts of Guix System. Make sure to visit it!
10545 @node operating-system Reference
10546 @section @code{operating-system} Reference
10548 This section summarizes all the options available in
10549 @code{operating-system} declarations (@pxref{Using the Configuration
10552 @deftp {Data Type} operating-system
10553 This is the data type representing an operating system configuration.
10554 By that, we mean all the global system configuration, not per-user
10555 configuration (@pxref{Using the Configuration System}).
10558 @item @code{kernel} (default: @var{linux-libre})
10559 The package object of the operating system kernel to use@footnote{Currently
10560 only the Linux-libre kernel is supported. In the future, it will be
10561 possible to use the GNU@tie{}Hurd.}.
10563 @item @code{kernel-arguments} (default: @code{'("quiet")})
10564 List of strings or gexps representing additional arguments to pass on
10565 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10567 @item @code{bootloader}
10568 The system bootloader configuration object. @xref{Bootloader Configuration}.
10571 This is the label (a string) as it appears in the bootloader's menu entry.
10572 The default label includes the kernel name and version.
10574 @item @code{keyboard-layout} (default: @code{#f})
10575 This field specifies the keyboard layout to use in the console. It can be
10576 either @code{#f}, in which case the default keyboard layout is used (usually
10577 US English), or a @code{<keyboard-layout>} record.
10579 This keyboard layout is in effect as soon as the kernel has booted. For
10580 instance, it is the keyboard layout in effect when you type a passphrase if
10581 your root file system is on a @code{luks-device-mapping} mapped device
10582 (@pxref{Mapped Devices}).
10585 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10586 that used by the graphical display server. @xref{Bootloader Configuration},
10587 for information on how to specify the bootloader's keyboard layout. @xref{X
10588 Window}, for information on how to specify the keyboard layout used by the X
10592 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10594 @cindex initial RAM disk
10595 The list of Linux kernel modules that need to be available in the
10596 initial RAM disk. @xref{Initial RAM Disk}.
10598 @item @code{initrd} (default: @code{base-initrd})
10599 A procedure that returns an initial RAM disk for the Linux
10600 kernel. This field is provided to support low-level customization and
10601 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10603 @item @code{firmware} (default: @code{%base-firmware})
10605 List of firmware packages loadable by the operating system kernel.
10607 The default includes firmware needed for Atheros- and Broadcom-based
10608 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10609 respectively). @xref{Hardware Considerations}, for more info on
10610 supported hardware.
10612 @item @code{host-name}
10615 @item @code{hosts-file}
10617 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10618 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10619 Reference Manual}). The default is a file with entries for
10620 @code{localhost} and @var{host-name}.
10622 @item @code{mapped-devices} (default: @code{'()})
10623 A list of mapped devices. @xref{Mapped Devices}.
10625 @item @code{file-systems}
10626 A list of file systems. @xref{File Systems}.
10628 @item @code{swap-devices} (default: @code{'()})
10629 @cindex swap devices
10630 A list of strings identifying devices or files to be used for ``swap
10631 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10632 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10633 It is possible to specify a swap file in a file system on a mapped
10634 device, provided that the necessary device mapping and file system are
10635 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10637 @item @code{users} (default: @code{%base-user-accounts})
10638 @itemx @code{groups} (default: @code{%base-groups})
10639 List of user accounts and groups. @xref{User Accounts}.
10641 If the @code{users} list lacks a user account with UID@tie{}0, a
10642 ``root'' account with UID@tie{}0 is automatically added.
10644 @item @code{skeletons} (default: @code{(default-skeletons)})
10645 A list target file name/file-like object tuples (@pxref{G-Expressions,
10646 file-like objects}). These are the skeleton files that will be added to
10647 the home directory of newly-created user accounts.
10649 For instance, a valid value may look like this:
10652 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10653 (".guile" ,(plain-file "guile"
10654 "(use-modules (ice-9 readline))
10655 (activate-readline)")))
10658 @item @code{issue} (default: @code{%default-issue})
10659 A string denoting the contents of the @file{/etc/issue} file, which is
10660 displayed when users log in on a text console.
10662 @item @code{packages} (default: @code{%base-packages})
10663 The set of packages installed in the global profile, which is accessible
10664 at @file{/run/current-system/profile}.
10666 The default set includes core utilities and it is good practice to
10667 install non-core utilities in user profiles (@pxref{Invoking guix
10670 @item @code{timezone}
10671 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10673 You can run the @command{tzselect} command to find out which timezone
10674 string corresponds to your region. Choosing an invalid timezone name
10675 causes @command{guix system} to fail.
10677 @item @code{locale} (default: @code{"en_US.utf8"})
10678 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10679 Library Reference Manual}). @xref{Locales}, for more information.
10681 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
10682 The list of locale definitions to be compiled and that may be used at
10683 run time. @xref{Locales}.
10685 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10686 The list of GNU@tie{}libc packages whose locale data and tools are used
10687 to build the locale definitions. @xref{Locales}, for compatibility
10688 considerations that justify this option.
10690 @item @code{name-service-switch} (default: @code{%default-nss})
10691 Configuration of the libc name service switch (NSS)---a
10692 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10695 @item @code{services} (default: @code{%base-services})
10696 A list of service objects denoting system services. @xref{Services}.
10698 @cindex essential services
10699 @item @code{essential-services} (default: ...)
10700 The list of ``essential services''---i.e., things like instances of
10701 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
10702 Reference}), which are derived from the operating system definition itself.
10703 As a user you should @emph{never} need to touch this field.
10705 @item @code{pam-services} (default: @code{(base-pam-services)})
10707 @cindex pluggable authentication modules
10708 Linux @dfn{pluggable authentication module} (PAM) services.
10709 @c FIXME: Add xref to PAM services section.
10711 @item @code{setuid-programs} (default: @var{%setuid-programs})
10712 List of string-valued G-expressions denoting setuid programs.
10713 @xref{Setuid Programs}.
10715 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10716 @cindex sudoers file
10717 The contents of the @file{/etc/sudoers} file as a file-like object
10718 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10720 This file specifies which users can use the @command{sudo} command, what
10721 they are allowed to do, and what privileges they may gain. The default
10722 is that only @code{root} and members of the @code{wheel} group may use
10727 @deffn {Scheme Syntax} this-operating-system
10728 When used in the @emph{lexical scope} of an operating system field definition,
10729 this identifier resolves to the operating system being defined.
10731 The example below shows how to refer to the operating system being defined in
10732 the definition of the @code{label} field:
10735 (use-modules (gnu) (guix))
10739 (label (package-full-name
10740 (operating-system-kernel this-operating-system))))
10743 It is an error to refer to @code{this-operating-system} outside an operating
10750 @section File Systems
10752 The list of file systems to be mounted is specified in the
10753 @code{file-systems} field of the operating system declaration
10754 (@pxref{Using the Configuration System}). Each file system is declared
10755 using the @code{file-system} form, like this:
10759 (mount-point "/home")
10760 (device "/dev/sda3")
10764 As usual, some of the fields are mandatory---those shown in the example
10765 above---while others can be omitted. These are described below.
10767 @deftp {Data Type} file-system
10768 Objects of this type represent file systems to be mounted. They
10769 contain the following members:
10773 This is a string specifying the type of the file system---e.g.,
10776 @item @code{mount-point}
10777 This designates the place where the file system is to be mounted.
10779 @item @code{device}
10780 This names the ``source'' of the file system. It can be one of three
10781 things: a file system label, a file system UUID, or the name of a
10782 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10783 systems without having to hard-code their actual device
10784 name@footnote{Note that, while it is tempting to use
10785 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10786 result, this is not recommended: These special device nodes are created
10787 by the udev daemon and may be unavailable at the time the device is
10790 @findex file-system-label
10791 File system labels are created using the @code{file-system-label}
10792 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10793 plain strings. Here's an example of a file system referred to by its
10794 label, as shown by the @command{e2label} command:
10798 (mount-point "/home")
10800 (device (file-system-label "my-home")))
10804 UUIDs are converted from their string representation (as shown by the
10805 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10806 @code{uuid} form expects 16-byte UUIDs as defined in
10807 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10808 form of UUID used by the ext2 family of file systems and others, but it
10809 is different from ``UUIDs'' found in FAT file systems, for instance.},
10814 (mount-point "/home")
10816 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10819 When the source of a file system is a mapped device (@pxref{Mapped
10820 Devices}), its @code{device} field @emph{must} refer to the mapped
10821 device name---e.g., @file{"/dev/mapper/root-partition"}.
10822 This is required so that
10823 the system knows that mounting the file system depends on having the
10824 corresponding device mapping established.
10826 @item @code{flags} (default: @code{'()})
10827 This is a list of symbols denoting mount flags. Recognized flags
10828 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10829 access to special files), @code{no-suid} (ignore setuid and setgid
10830 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
10831 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
10832 Library Reference Manual}, for more information on these flags.
10834 @item @code{options} (default: @code{#f})
10835 This is either @code{#f}, or a string denoting mount options passed to the
10836 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
10837 Reference Manual}, for details and run @command{man 8 mount} for options for
10838 various file systems.
10840 @item @code{mount?} (default: @code{#t})
10841 This value indicates whether to automatically mount the file system when
10842 the system is brought up. When set to @code{#f}, the file system gets
10843 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10844 is not automatically mounted.
10846 @item @code{needed-for-boot?} (default: @code{#f})
10847 This Boolean value indicates whether the file system is needed when
10848 booting. If that is true, then the file system is mounted when the
10849 initial RAM disk (initrd) is loaded. This is always the case, for
10850 instance, for the root file system.
10852 @item @code{check?} (default: @code{#t})
10853 This Boolean indicates whether the file system needs to be checked for
10854 errors before being mounted.
10856 @item @code{create-mount-point?} (default: @code{#f})
10857 When true, the mount point is created if it does not exist yet.
10859 @item @code{dependencies} (default: @code{'()})
10860 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10861 representing file systems that must be mounted or mapped devices that
10862 must be opened before (and unmounted or closed after) this one.
10864 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10865 a dependency of @file{/sys/fs/cgroup/cpu} and
10866 @file{/sys/fs/cgroup/memory}.
10868 Another example is a file system that depends on a mapped device, for
10869 example for an encrypted partition (@pxref{Mapped Devices}).
10873 The @code{(gnu system file-systems)} exports the following useful
10876 @defvr {Scheme Variable} %base-file-systems
10877 These are essential file systems that are required on normal systems,
10878 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10879 below.) Operating system declarations should always contain at least
10883 @defvr {Scheme Variable} %pseudo-terminal-file-system
10884 This is the file system to be mounted as @file{/dev/pts}. It supports
10885 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10886 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10887 Manual}). Pseudo-terminals are used by terminal emulators such as
10891 @defvr {Scheme Variable} %shared-memory-file-system
10892 This file system is mounted as @file{/dev/shm} and is used to support
10893 memory sharing across processes (@pxref{Memory-mapped I/O,
10894 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10897 @defvr {Scheme Variable} %immutable-store
10898 This file system performs a read-only ``bind mount'' of
10899 @file{/gnu/store}, making it read-only for all the users including
10900 @code{root}. This prevents against accidental modification by software
10901 running as @code{root} or by system administrators.
10903 The daemon itself is still able to write to the store: it remounts it
10904 read-write in its own ``name space.''
10907 @defvr {Scheme Variable} %binary-format-file-system
10908 The @code{binfmt_misc} file system, which allows handling of arbitrary
10909 executable file types to be delegated to user space. This requires the
10910 @code{binfmt.ko} kernel module to be loaded.
10913 @defvr {Scheme Variable} %fuse-control-file-system
10914 The @code{fusectl} file system, which allows unprivileged users to mount
10915 and unmount user-space FUSE file systems. This requires the
10916 @code{fuse.ko} kernel module to be loaded.
10919 @node Mapped Devices
10920 @section Mapped Devices
10922 @cindex device mapping
10923 @cindex mapped devices
10924 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10925 such as a hard disk partition, can be @dfn{mapped} into another device,
10926 usually in @code{/dev/mapper/},
10927 with additional processing over the data that flows through
10928 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10929 concept of a ``mapped device'' and that of a file system: both boil down
10930 to @emph{translating} input/output operations made on a file to
10931 operations on its backing store. Thus, the Hurd implements mapped
10932 devices, like file systems, using the generic @dfn{translator} mechanism
10933 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10934 typical example is encryption device mapping: all writes to the mapped
10935 device are encrypted, and all reads are deciphered, transparently.
10936 Guix extends this notion by considering any device or set of devices that
10937 are @dfn{transformed} in some way to create a new device; for instance,
10938 RAID devices are obtained by @dfn{assembling} several other devices, such
10939 as hard disks or partitions, into a new one that behaves as one partition.
10940 Other examples, not yet implemented, are LVM logical volumes.
10942 Mapped devices are declared using the @code{mapped-device} form,
10943 defined as follows; for examples, see below.
10945 @deftp {Data Type} mapped-device
10946 Objects of this type represent device mappings that will be made when
10947 the system boots up.
10951 This is either a string specifying the name of the block device to be mapped,
10952 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10953 need to be assembled for creating a new one.
10956 This string specifies the name of the resulting mapped device. For
10957 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
10958 specifying @code{"my-partition"} leads to the creation of
10959 the @code{"/dev/mapper/my-partition"} device.
10960 For RAID devices of type @code{raid-device-mapping}, the full device name
10961 such as @code{"/dev/md0"} needs to be given.
10964 This must be a @code{mapped-device-kind} object, which specifies how
10965 @var{source} is mapped to @var{target}.
10969 @defvr {Scheme Variable} luks-device-mapping
10970 This defines LUKS block device encryption using the @command{cryptsetup}
10971 command from the package with the same name. It relies on the
10972 @code{dm-crypt} Linux kernel module.
10975 @defvr {Scheme Variable} raid-device-mapping
10976 This defines a RAID device, which is assembled using the @code{mdadm}
10977 command from the package with the same name. It requires a Linux kernel
10978 module for the appropriate RAID level to be loaded, such as @code{raid456}
10979 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
10982 @cindex disk encryption
10984 The following example specifies a mapping from @file{/dev/sda3} to
10985 @file{/dev/mapper/home} using LUKS---the
10986 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
10987 standard mechanism for disk encryption.
10988 The @file{/dev/mapper/home}
10989 device can then be used as the @code{device} of a @code{file-system}
10990 declaration (@pxref{File Systems}).
10994 (source "/dev/sda3")
10996 (type luks-device-mapping))
10999 Alternatively, to become independent of device numbering, one may obtain
11000 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11004 cryptsetup luksUUID /dev/sda3
11007 and use it as follows:
11011 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11013 (type luks-device-mapping))
11016 @cindex swap encryption
11017 It is also desirable to encrypt swap space, since swap space may contain
11018 sensitive data. One way to accomplish that is to use a swap file in a
11019 file system on a device mapped via LUKS encryption. In this way, the
11020 swap file is encrypted because the entire device is encrypted.
11021 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11023 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11024 may be declared as follows:
11028 (source (list "/dev/sda1" "/dev/sdb1"))
11029 (target "/dev/md0")
11030 (type raid-device-mapping))
11033 The @file{/dev/md0} device can then be used as the @code{device} of a
11034 @code{file-system} declaration (@pxref{File Systems}).
11035 Note that the RAID level need not be given; it is chosen during the
11036 initial creation and formatting of the RAID device and is determined
11037 automatically later.
11040 @node User Accounts
11041 @section User Accounts
11045 @cindex user accounts
11046 User accounts and groups are entirely managed through the
11047 @code{operating-system} declaration. They are specified with the
11048 @code{user-account} and @code{user-group} forms:
11054 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11055 "audio" ;sound card
11056 "video" ;video devices such as webcams
11057 "cdrom")) ;the good ol' CD-ROM
11058 (comment "Bob's sister")
11059 (home-directory "/home/alice"))
11062 When booting or upon completion of @command{guix system reconfigure},
11063 the system ensures that only the user accounts and groups specified in
11064 the @code{operating-system} declaration exist, and with the specified
11065 properties. Thus, account or group creations or modifications made by
11066 directly invoking commands such as @command{useradd} are lost upon
11067 reconfiguration or reboot. This ensures that the system remains exactly
11070 @deftp {Data Type} user-account
11071 Objects of this type represent user accounts. The following members may
11076 The name of the user account.
11080 This is the name (a string) or identifier (a number) of the user group
11081 this account belongs to.
11083 @item @code{supplementary-groups} (default: @code{'()})
11084 Optionally, this can be defined as a list of group names that this
11085 account belongs to.
11087 @item @code{uid} (default: @code{#f})
11088 This is the user ID for this account (a number), or @code{#f}. In the
11089 latter case, a number is automatically chosen by the system when the
11090 account is created.
11092 @item @code{comment} (default: @code{""})
11093 A comment about the account, such as the account owner's full name.
11095 @item @code{home-directory}
11096 This is the name of the home directory for the account.
11098 @item @code{create-home-directory?} (default: @code{#t})
11099 Indicates whether the home directory of this account should be created
11100 if it does not exist yet.
11102 @item @code{shell} (default: Bash)
11103 This is a G-expression denoting the file name of a program to be used as
11104 the shell (@pxref{G-Expressions}).
11106 @item @code{system?} (default: @code{#f})
11107 This Boolean value indicates whether the account is a ``system''
11108 account. System accounts are sometimes treated specially; for instance,
11109 graphical login managers do not list them.
11111 @anchor{user-account-password}
11112 @cindex password, for user accounts
11113 @item @code{password} (default: @code{#f})
11114 You would normally leave this field to @code{#f}, initialize user
11115 passwords as @code{root} with the @command{passwd} command, and then let
11116 users change it with @command{passwd}. Passwords set with
11117 @command{passwd} are of course preserved across reboot and
11120 If you @emph{do} want to set an initial password for an account, then
11121 this field must contain the encrypted password, as a string. You can use the
11122 @code{crypt} procedure for this purpose:
11129 ;; Specify a SHA-512-hashed initial password.
11130 (password (crypt "InitialPassword!" "$6$abc")))
11134 The hash of this initial password will be available in a file in
11135 @file{/gnu/store}, readable by all the users, so this method must be used with
11139 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11140 more information on password encryption, and @ref{Encryption,,, guile, GNU
11141 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11147 User group declarations are even simpler:
11150 (user-group (name "students"))
11153 @deftp {Data Type} user-group
11154 This type is for, well, user groups. There are just a few fields:
11158 The name of the group.
11160 @item @code{id} (default: @code{#f})
11161 The group identifier (a number). If @code{#f}, a new number is
11162 automatically allocated when the group is created.
11164 @item @code{system?} (default: @code{#f})
11165 This Boolean value indicates whether the group is a ``system'' group.
11166 System groups have low numerical IDs.
11168 @item @code{password} (default: @code{#f})
11169 What, user groups can have a password? Well, apparently yes. Unless
11170 @code{#f}, this field specifies the password of the group.
11175 For convenience, a variable lists all the basic user groups one may
11178 @defvr {Scheme Variable} %base-groups
11179 This is the list of basic user groups that users and/or packages expect
11180 to be present on the system. This includes groups such as ``root'',
11181 ``wheel'', and ``users'', as well as groups used to control access to
11182 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11185 @defvr {Scheme Variable} %base-user-accounts
11186 This is the list of basic system accounts that programs may expect to
11187 find on a GNU/Linux system, such as the ``nobody'' account.
11189 Note that the ``root'' account is not included here. It is a
11190 special-case and is automatically added whether or not it is specified.
11193 @node Keyboard Layout
11194 @section Keyboard Layout
11196 @cindex keyboard layout
11198 To specify what each key of your keyboard does, you need to tell the operating
11199 system what @dfn{keyboard layout} you want to use. The default, when nothing
11200 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11201 However, German speakers will usually prefer the German QWERTZ layout, French
11202 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11203 or bépo, and they might even want to further customize the effect of some of
11204 the keys. This section explains how to get that done.
11206 @cindex keyboard layout, definition
11207 There are three components that will want to know about your keyboard layout:
11211 The @emph{bootloader} may want to know what keyboard layout you want to use
11212 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11213 you want, for instance, to make sure that you can type the passphrase of your
11214 encrypted root partition using the right layout.
11217 The @emph{operating system kernel}, Linux, will need that so that the console
11218 is properly configured (@pxref{operating-system Reference,
11219 @code{keyboard-layout}}).
11222 The @emph{graphical display server}, usually Xorg, also has its own idea of
11223 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11226 Guix allows you to configure all three separately but, fortunately, it allows
11227 you to share the same keyboard layout for all three components.
11229 @cindex XKB, keyboard layouts
11230 Keyboard layouts are represented by records created by the
11231 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11232 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11233 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11234 optional variant name, an optional keyboard model name, and a possibly empty
11235 list of additional options. In most cases the layout name is all you care
11236 about. Here are a few example:
11239 ;; The German QWERTZ layout. Here we assume a standard
11240 ;; "pc105" keyboard model.
11241 (keyboard-layout "de")
11243 ;; The bépo variant of the French layout.
11244 (keyboard-layout "fr" "bepo")
11246 ;; The Catalan layout.
11247 (keyboard-layout "es" "cat")
11249 ;; The Latin American Spanish layout. In addition, the
11250 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11251 ;; and the "Menu" key is used as a "Compose" key to enter
11252 ;; accented letters.
11253 (keyboard-layout "latam"
11254 #:options '("ctrl:nocaps" "compose:menu"))
11256 ;; The Russian layout for a ThinkPad keyboard.
11257 (keyboard-layout "ru" #:model "thinkpad")
11259 ;; The "US international" layout, which is the US layout plus
11260 ;; dead keys to enter accented characters. This is for an
11261 ;; Apple MacBook keyboard.
11262 (keyboard-layout "us" "intl" #:model "macbook78")
11265 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11266 for a complete list of supported layouts, variants, and models.
11268 @cindex keyboard layout, configuration
11269 Let's say you want your system to use the Turkish keyboard layout throughout
11270 your system---bootloader, console, and Xorg. Here's what your system
11271 configuration would look like:
11273 @findex set-xorg-configuration
11275 ;; Using the Turkish layout for the bootloader, the console,
11280 (keyboard-layout (keyboard-layout "tr")) ;for the console
11281 (bootloader (bootloader-configuration
11282 (bootloader grub-efi-bootloader)
11283 (target "/boot/efi")
11284 (keyboard-layout keyboard-layout))) ;for GRUB
11285 (services (cons (set-xorg-configuration
11286 (xorg-configuration ;for Xorg
11287 (keyboard-layout keyboard-layout)))
11288 %desktop-services)))
11291 In the example above, for GRUB and for Xorg, we just refer to the
11292 @code{keyboard-layout} field defined above, but we could just as well refer to
11293 a different layout. The @code{set-xorg-configuration} procedure communicates
11294 the desired Xorg configuration to the graphical log-in manager, by default
11297 We've discussed how to specify the @emph{default} keyboard layout of your
11298 system when it starts, but you can also adjust it at run time:
11302 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11303 where you can select one or more keyboard layouts.
11306 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11307 allows you to change the current layout. For example, this is how you would
11308 change the layout to US Dvorak:
11311 setxkbmap us dvorak
11315 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11316 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11317 keyboard layout categorization described above. The command below loads the
11318 French bépo layout:
11329 A @dfn{locale} defines cultural conventions for a particular language
11330 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11331 Reference Manual}). Each locale has a name that typically has the form
11332 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11333 @code{fr_LU.utf8} designates the locale for the French language, with
11334 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11336 @cindex locale definition
11337 Usually, you will want to specify the default locale for the machine
11338 using the @code{locale} field of the @code{operating-system} declaration
11339 (@pxref{operating-system Reference, @code{locale}}).
11341 The selected locale is automatically added to the @dfn{locale
11342 definitions} known to the system if needed, with its codeset inferred
11343 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11344 @code{UTF-8} codeset. Additional locale definitions can be specified in
11345 the @code{locale-definitions} slot of @code{operating-system}---this is
11346 useful, for instance, if the codeset could not be inferred from the
11347 locale name. The default set of locale definitions includes some widely
11348 used locales, but not all the available locales, in order to save space.
11350 For instance, to add the North Frisian locale for Germany, the value of
11354 (cons (locale-definition
11355 (name "fy_DE.utf8") (source "fy_DE"))
11356 %default-locale-definitions)
11359 Likewise, to save space, one might want @code{locale-definitions} to
11360 list only the locales that are actually used, as in:
11363 (list (locale-definition
11364 (name "ja_JP.eucjp") (source "ja_JP")
11365 (charset "EUC-JP")))
11369 The compiled locale definitions are available at
11370 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11371 version, which is the default location where the GNU@tie{}libc provided
11372 by Guix looks for locale data. This can be overridden using the
11373 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11374 @code{LOCPATH} and locale packages}).
11376 The @code{locale-definition} form is provided by the @code{(gnu system
11377 locale)} module. Details are given below.
11379 @deftp {Data Type} locale-definition
11380 This is the data type of a locale definition.
11385 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11386 Reference Manual}, for more information on locale names.
11388 @item @code{source}
11389 The name of the source for that locale. This is typically the
11390 @code{@var{language}_@var{territory}} part of the locale name.
11392 @item @code{charset} (default: @code{"UTF-8"})
11393 The ``character set'' or ``code set'' for that locale,
11394 @uref{https://www.iana.org/assignments/character-sets, as defined by
11400 @defvr {Scheme Variable} %default-locale-definitions
11401 A list of commonly used UTF-8 locales, used as the default
11402 value of the @code{locale-definitions} field of @code{operating-system}
11405 @cindex locale name
11406 @cindex normalized codeset in locale names
11407 These locale definitions use the @dfn{normalized codeset} for the part
11408 that follows the dot in the name (@pxref{Using gettextized software,
11409 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11410 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11411 @code{uk_UA.UTF-8}.
11414 @subsection Locale Data Compatibility Considerations
11416 @cindex incompatibility, of locale data
11417 @code{operating-system} declarations provide a @code{locale-libcs} field
11418 to specify the GNU@tie{}libc packages that are used to compile locale
11419 declarations (@pxref{operating-system Reference}). ``Why would I
11420 care?'', you may ask. Well, it turns out that the binary format of
11421 locale data is occasionally incompatible from one libc version to
11424 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11425 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11426 For instance, a program linked against libc version 2.21 is unable to
11427 read locale data produced with libc 2.22; worse, that program
11428 @emph{aborts} instead of simply ignoring the incompatible locale
11429 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11430 the incompatible locale data, which is already an improvement.}.
11431 Similarly, a program linked against libc 2.22 can read most, but not
11432 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11433 data is incompatible); thus calls to @code{setlocale} may fail, but
11434 programs will not abort.
11436 The ``problem'' with Guix is that users have a lot of freedom: They can
11437 choose whether and when to upgrade software in their profiles, and might
11438 be using a libc version different from the one the system administrator
11439 used to build the system-wide locale data.
11441 Fortunately, unprivileged users can also install their own locale data
11442 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11443 @code{GUIX_LOCPATH} and locale packages}).
11445 Still, it is best if the system-wide locale data at
11446 @file{/run/current-system/locale} is built for all the libc versions
11447 actually in use on the system, so that all the programs can access
11448 it---this is especially crucial on a multi-user system. To do that, the
11449 administrator can specify several libc packages in the
11450 @code{locale-libcs} field of @code{operating-system}:
11453 (use-package-modules base)
11457 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11460 This example would lead to a system containing locale definitions for
11461 both libc 2.21 and the current version of libc in
11462 @file{/run/current-system/locale}.
11468 @cindex system services
11469 An important part of preparing an @code{operating-system} declaration is
11470 listing @dfn{system services} and their configuration (@pxref{Using the
11471 Configuration System}). System services are typically daemons launched
11472 when the system boots, or other actions needed at that time---e.g.,
11473 configuring network access.
11475 Guix has a broad definition of ``service'' (@pxref{Service
11476 Composition}), but many services are managed by the GNU@tie{}Shepherd
11477 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11478 command allows you to list the available services, show their status,
11479 start and stop them, or do other specific operations (@pxref{Jump
11480 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11486 The above command, run as @code{root}, lists the currently defined
11487 services. The @command{herd doc} command shows a synopsis of the given
11488 service and its associated actions:
11492 Run libc's name service cache daemon (nscd).
11494 # herd doc nscd action invalidate
11495 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11498 The @command{start}, @command{stop}, and @command{restart} sub-commands
11499 have the effect you would expect. For instance, the commands below stop
11500 the nscd service and restart the Xorg display server:
11504 Service nscd has been stopped.
11505 # herd restart xorg-server
11506 Service xorg-server has been stopped.
11507 Service xorg-server has been started.
11510 The following sections document the available services, starting with
11511 the core services, that may be used in an @code{operating-system}
11515 * Base Services:: Essential system services.
11516 * Scheduled Job Execution:: The mcron service.
11517 * Log Rotation:: The rottlog service.
11518 * Networking Services:: Network setup, SSH daemon, etc.
11519 * X Window:: Graphical display.
11520 * Printing Services:: Local and remote printer support.
11521 * Desktop Services:: D-Bus and desktop services.
11522 * Sound Services:: ALSA and Pulseaudio services.
11523 * Database Services:: SQL databases, key-value stores, etc.
11524 * Mail Services:: IMAP, POP3, SMTP, and all that.
11525 * Messaging Services:: Messaging services.
11526 * Telephony Services:: Telephony services.
11527 * Monitoring Services:: Monitoring services.
11528 * Kerberos Services:: Kerberos services.
11529 * LDAP Services:: LDAP services.
11530 * Web Services:: Web servers.
11531 * Certificate Services:: TLS certificates via Let's Encrypt.
11532 * DNS Services:: DNS daemons.
11533 * VPN Services:: VPN daemons.
11534 * Network File System:: NFS related services.
11535 * Continuous Integration:: The Cuirass service.
11536 * Power Management Services:: Extending battery life.
11537 * Audio Services:: The MPD.
11538 * Virtualization Services:: Virtualization services.
11539 * Version Control Services:: Providing remote access to Git repositories.
11540 * Game Services:: Game servers.
11541 * Miscellaneous Services:: Other services.
11544 @node Base Services
11545 @subsection Base Services
11547 The @code{(gnu services base)} module provides definitions for the basic
11548 services that one expects from the system. The services exported by
11549 this module are listed below.
11551 @defvr {Scheme Variable} %base-services
11552 This variable contains a list of basic services (@pxref{Service Types
11553 and Services}, for more information on service objects) one would
11554 expect from the system: a login service (mingetty) on each tty, syslogd,
11555 the libc name service cache daemon (nscd), the udev device manager, and
11558 This is the default value of the @code{services} field of
11559 @code{operating-system} declarations. Usually, when customizing a
11560 system, you will want to append services to @code{%base-services}, like
11564 (append (list (service avahi-service-type)
11565 (service openssh-service-type))
11570 @defvr {Scheme Variable} special-files-service-type
11571 This is the service that sets up ``special files'' such as
11572 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11574 The value associated with @code{special-files-service-type} services
11575 must be a list of tuples where the first element is the ``special file''
11576 and the second element is its target. By default it is:
11578 @cindex @file{/bin/sh}
11579 @cindex @file{sh}, in @file{/bin}
11581 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11584 @cindex @file{/usr/bin/env}
11585 @cindex @file{env}, in @file{/usr/bin}
11586 If you want to add, say, @code{/usr/bin/env} to your system, you can
11590 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11591 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11594 Since this is part of @code{%base-services}, you can use
11595 @code{modify-services} to customize the set of special files
11596 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11597 to add a special file is @i{via} the @code{extra-special-file} procedure
11601 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11602 Use @var{target} as the ``special file'' @var{file}.
11604 For example, adding the following lines to the @code{services} field of
11605 your operating system declaration leads to a @file{/usr/bin/env}
11609 (extra-special-file "/usr/bin/env"
11610 (file-append coreutils "/bin/env"))
11614 @deffn {Scheme Procedure} host-name-service @var{name}
11615 Return a service that sets the host name to @var{name}.
11618 @deffn {Scheme Procedure} login-service @var{config}
11619 Return a service to run login according to @var{config}, a
11620 @code{<login-configuration>} object, which specifies the message of the day,
11621 among other things.
11624 @deftp {Data Type} login-configuration
11625 This is the data type representing the configuration of login.
11630 @cindex message of the day
11631 A file-like object containing the ``message of the day''.
11633 @item @code{allow-empty-passwords?} (default: @code{#t})
11634 Allow empty passwords by default so that first-time users can log in when
11635 the 'root' account has just been created.
11640 @deffn {Scheme Procedure} mingetty-service @var{config}
11641 Return a service to run mingetty according to @var{config}, a
11642 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11646 @deftp {Data Type} mingetty-configuration
11647 This is the data type representing the configuration of Mingetty, which
11648 provides the default implementation of virtual console log-in.
11653 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11655 @item @code{auto-login} (default: @code{#f})
11656 When true, this field must be a string denoting the user name under
11657 which the system automatically logs in. When it is @code{#f}, a
11658 user name and password must be entered to log in.
11660 @item @code{login-program} (default: @code{#f})
11661 This must be either @code{#f}, in which case the default log-in program
11662 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11663 the name of the log-in program.
11665 @item @code{login-pause?} (default: @code{#f})
11666 When set to @code{#t} in conjunction with @var{auto-login}, the user
11667 will have to press a key before the log-in shell is launched.
11669 @item @code{mingetty} (default: @var{mingetty})
11670 The Mingetty package to use.
11675 @deffn {Scheme Procedure} agetty-service @var{config}
11676 Return a service to run agetty according to @var{config}, an
11677 @code{<agetty-configuration>} object, which specifies the tty to run,
11678 among other things.
11681 @deftp {Data Type} agetty-configuration
11682 This is the data type representing the configuration of agetty, which
11683 implements virtual and serial console log-in. See the @code{agetty(8)}
11684 man page for more information.
11689 The name of the console this agetty runs on, as a string---e.g.,
11690 @code{"ttyS0"}. This argument is optional, it will default to
11691 a reasonable default serial port used by the kernel Linux.
11693 For this, if there is a value for an option @code{agetty.tty} in the kernel
11694 command line, agetty will extract the device name of the serial port
11695 from it and use that.
11697 If not and if there is a value for an option @code{console} with a tty in
11698 the Linux command line, agetty will extract the device name of the
11699 serial port from it and use that.
11701 In both cases, agetty will leave the other serial device settings
11702 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11705 @item @code{baud-rate} (default: @code{#f})
11706 A string containing a comma-separated list of one or more baud rates, in
11709 @item @code{term} (default: @code{#f})
11710 A string containing the value used for the @code{TERM} environment
11713 @item @code{eight-bits?} (default: @code{#f})
11714 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11717 @item @code{auto-login} (default: @code{#f})
11718 When passed a login name, as a string, the specified user will be logged
11719 in automatically without prompting for their login name or password.
11721 @item @code{no-reset?} (default: @code{#f})
11722 When @code{#t}, don't reset terminal cflags (control modes).
11724 @item @code{host} (default: @code{#f})
11725 This accepts a string containing the "login_host", which will be written
11726 into the @file{/var/run/utmpx} file.
11728 @item @code{remote?} (default: @code{#f})
11729 When set to @code{#t} in conjunction with @var{host}, this will add an
11730 @code{-r} fakehost option to the command line of the login program
11731 specified in @var{login-program}.
11733 @item @code{flow-control?} (default: @code{#f})
11734 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11736 @item @code{no-issue?} (default: @code{#f})
11737 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11738 not be displayed before presenting the login prompt.
11740 @item @code{init-string} (default: @code{#f})
11741 This accepts a string that will be sent to the tty or modem before
11742 sending anything else. It can be used to initialize a modem.
11744 @item @code{no-clear?} (default: @code{#f})
11745 When set to @code{#t}, agetty will not clear the screen before showing
11748 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11749 This must be either a gexp denoting the name of a log-in program, or
11750 unset, in which case the default value is the @command{login} from the
11753 @item @code{local-line} (default: @code{#f})
11754 Control the CLOCAL line flag. This accepts one of three symbols as
11755 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11756 the default value chosen by agetty is @code{'auto}.
11758 @item @code{extract-baud?} (default: @code{#f})
11759 When set to @code{#t}, instruct agetty to try to extract the baud rate
11760 from the status messages produced by certain types of modems.
11762 @item @code{skip-login?} (default: @code{#f})
11763 When set to @code{#t}, do not prompt the user for a login name. This
11764 can be used with @var{login-program} field to use non-standard login
11767 @item @code{no-newline?} (default: @code{#f})
11768 When set to @code{#t}, do not print a newline before printing the
11769 @file{/etc/issue} file.
11771 @c Is this dangerous only when used with login-program, or always?
11772 @item @code{login-options} (default: @code{#f})
11773 This option accepts a string containing options that are passed to the
11774 login program. When used with the @var{login-program}, be aware that a
11775 malicious user could try to enter a login name containing embedded
11776 options that could be parsed by the login program.
11778 @item @code{login-pause} (default: @code{#f})
11779 When set to @code{#t}, wait for any key before showing the login prompt.
11780 This can be used in conjunction with @var{auto-login} to save memory by
11781 lazily spawning shells.
11783 @item @code{chroot} (default: @code{#f})
11784 Change root to the specified directory. This option accepts a directory
11787 @item @code{hangup?} (default: @code{#f})
11788 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11789 specified terminal.
11791 @item @code{keep-baud?} (default: @code{#f})
11792 When set to @code{#t}, try to keep the existing baud rate. The baud
11793 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11796 @item @code{timeout} (default: @code{#f})
11797 When set to an integer value, terminate if no user name could be read
11798 within @var{timeout} seconds.
11800 @item @code{detect-case?} (default: @code{#f})
11801 When set to @code{#t}, turn on support for detecting an uppercase-only
11802 terminal. This setting will detect a login name containing only
11803 uppercase letters as indicating an uppercase-only terminal and turn on
11804 some upper-to-lower case conversions. Note that this will not support
11805 Unicode characters.
11807 @item @code{wait-cr?} (default: @code{#f})
11808 When set to @code{#t}, wait for the user or modem to send a
11809 carriage-return or linefeed character before displaying
11810 @file{/etc/issue} or login prompt. This is typically used with the
11811 @var{init-string} option.
11813 @item @code{no-hints?} (default: @code{#f})
11814 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11817 @item @code{no-hostname?} (default: @code{#f})
11818 By default, the hostname is printed. When this option is set to
11819 @code{#t}, no hostname will be shown at all.
11821 @item @code{long-hostname?} (default: @code{#f})
11822 By default, the hostname is only printed until the first dot. When this
11823 option is set to @code{#t}, the fully qualified hostname by
11824 @code{gethostname} or @code{getaddrinfo} is shown.
11826 @item @code{erase-characters} (default: @code{#f})
11827 This option accepts a string of additional characters that should be
11828 interpreted as backspace when the user types their login name.
11830 @item @code{kill-characters} (default: @code{#f})
11831 This option accepts a string that should be interpreted to mean "ignore
11832 all previous characters" (also called a "kill" character) when the user
11833 types their login name.
11835 @item @code{chdir} (default: @code{#f})
11836 This option accepts, as a string, a directory path that will be changed
11839 @item @code{delay} (default: @code{#f})
11840 This options accepts, as an integer, the number of seconds to sleep
11841 before opening the tty and displaying the login prompt.
11843 @item @code{nice} (default: @code{#f})
11844 This option accepts, as an integer, the nice value with which to run the
11845 @command{login} program.
11847 @item @code{extra-options} (default: @code{'()})
11848 This option provides an "escape hatch" for the user to provide arbitrary
11849 command-line arguments to @command{agetty} as a list of strings.
11854 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11855 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11856 according to @var{config}, a @code{<kmscon-configuration>} object, which
11857 specifies the tty to run, among other things.
11860 @deftp {Data Type} kmscon-configuration
11861 This is the data type representing the configuration of Kmscon, which
11862 implements virtual console log-in.
11866 @item @code{virtual-terminal}
11867 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11869 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11870 A gexp denoting the name of the log-in program. The default log-in program is
11871 @command{login} from the Shadow tool suite.
11873 @item @code{login-arguments} (default: @code{'("-p")})
11874 A list of arguments to pass to @command{login}.
11876 @item @code{auto-login} (default: @code{#f})
11877 When passed a login name, as a string, the specified user will be logged
11878 in automatically without prompting for their login name or password.
11880 @item @code{hardware-acceleration?} (default: #f)
11881 Whether to use hardware acceleration.
11883 @item @code{kmscon} (default: @var{kmscon})
11884 The Kmscon package to use.
11889 @cindex name service cache daemon
11891 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11892 [#:name-services '()]
11893 Return a service that runs the libc name service cache daemon (nscd) with the
11894 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11895 Service Switch}, for an example.
11897 For convenience, the Shepherd service for nscd provides the following actions:
11901 @cindex cache invalidation, nscd
11902 @cindex nscd, cache invalidation
11903 This invalidate the given cache. For instance, running:
11906 herd invalidate nscd hosts
11910 invalidates the host name lookup cache of nscd.
11913 Running @command{herd statistics nscd} displays information about nscd usage
11919 @defvr {Scheme Variable} %nscd-default-configuration
11920 This is the default @code{<nscd-configuration>} value (see below) used
11921 by @code{nscd-service}. It uses the caches defined by
11922 @var{%nscd-default-caches}; see below.
11925 @deftp {Data Type} nscd-configuration
11926 This is the data type representing the name service cache daemon (nscd)
11931 @item @code{name-services} (default: @code{'()})
11932 List of packages denoting @dfn{name services} that must be visible to
11933 the nscd---e.g., @code{(list @var{nss-mdns})}.
11935 @item @code{glibc} (default: @var{glibc})
11936 Package object denoting the GNU C Library providing the @command{nscd}
11939 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11940 Name of the nscd log file. This is where debugging output goes when
11941 @code{debug-level} is strictly positive.
11943 @item @code{debug-level} (default: @code{0})
11944 Integer denoting the debugging levels. Higher numbers mean that more
11945 debugging output is logged.
11947 @item @code{caches} (default: @var{%nscd-default-caches})
11948 List of @code{<nscd-cache>} objects denoting things to be cached; see
11954 @deftp {Data Type} nscd-cache
11955 Data type representing a cache database of nscd and its parameters.
11959 @item @code{database}
11960 This is a symbol representing the name of the database to be cached.
11961 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
11962 @code{services}, which designate the corresponding NSS database
11963 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
11965 @item @code{positive-time-to-live}
11966 @itemx @code{negative-time-to-live} (default: @code{20})
11967 A number representing the number of seconds during which a positive or
11968 negative lookup result remains in cache.
11970 @item @code{check-files?} (default: @code{#t})
11971 Whether to check for updates of the files corresponding to
11974 For instance, when @var{database} is @code{hosts}, setting this flag
11975 instructs nscd to check for updates in @file{/etc/hosts} and to take
11978 @item @code{persistent?} (default: @code{#t})
11979 Whether the cache should be stored persistently on disk.
11981 @item @code{shared?} (default: @code{#t})
11982 Whether the cache should be shared among users.
11984 @item @code{max-database-size} (default: 32@tie{}MiB)
11985 Maximum size in bytes of the database cache.
11987 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
11988 @c settings, so leave them out.
11993 @defvr {Scheme Variable} %nscd-default-caches
11994 List of @code{<nscd-cache>} objects used by default by
11995 @code{nscd-configuration} (see above).
11997 It enables persistent and aggressive caching of service and host name
11998 lookups. The latter provides better host name lookup performance,
11999 resilience in the face of unreliable name servers, and also better
12000 privacy---often the result of host name lookups is in local cache, so
12001 external name servers do not even need to be queried.
12004 @anchor{syslog-configuration-type}
12007 @deftp {Data Type} syslog-configuration
12008 This data type represents the configuration of the syslog daemon.
12011 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12012 The syslog daemon to use.
12014 @item @code{config-file} (default: @code{%default-syslog.conf})
12015 The syslog configuration file to use.
12020 @anchor{syslog-service}
12022 @deffn {Scheme Procedure} syslog-service @var{config}
12023 Return a service that runs a syslog daemon according to @var{config}.
12025 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12026 information on the configuration file syntax.
12029 @defvr {Scheme Variable} guix-service-type
12030 This is the type of the service that runs the build daemon,
12031 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12032 @code{guix-configuration} record as described below.
12035 @anchor{guix-configuration-type}
12036 @deftp {Data Type} guix-configuration
12037 This data type represents the configuration of the Guix build daemon.
12038 @xref{Invoking guix-daemon}, for more information.
12041 @item @code{guix} (default: @var{guix})
12042 The Guix package to use.
12044 @item @code{build-group} (default: @code{"guixbuild"})
12045 Name of the group for build user accounts.
12047 @item @code{build-accounts} (default: @code{10})
12048 Number of build user accounts to create.
12050 @item @code{authorize-key?} (default: @code{#t})
12051 @cindex substitutes, authorization thereof
12052 Whether to authorize the substitute keys listed in
12053 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12054 (@pxref{Substitutes}).
12056 @vindex %default-authorized-guix-keys
12057 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12058 The list of authorized key files for archive imports, as a list of
12059 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12060 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12062 @item @code{use-substitutes?} (default: @code{#t})
12063 Whether to use substitutes.
12065 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12066 The list of URLs where to look for substitutes by default.
12068 @item @code{max-silent-time} (default: @code{0})
12069 @itemx @code{timeout} (default: @code{0})
12070 The number of seconds of silence and the number of seconds of activity,
12071 respectively, after which a build process times out. A value of zero
12072 disables the timeout.
12074 @item @code{log-compression} (default: @code{'bzip2})
12075 The type of compression used for build logs---one of @code{gzip},
12076 @code{bzip2}, or @code{none}.
12078 @item @code{extra-options} (default: @code{'()})
12079 List of extra command-line options for @command{guix-daemon}.
12081 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12082 File where @command{guix-daemon}'s standard output and standard error
12085 @item @code{http-proxy} (default: @code{#f})
12086 The HTTP proxy used for downloading fixed-output derivations and
12089 @item @code{tmpdir} (default: @code{#f})
12090 A directory path where the @command{guix-daemon} will perform builds.
12095 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12096 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12097 udev rules can be provided as a list of files through the @var{rules}
12098 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12099 @code{(gnu services base)} simplify the creation of such rule files.
12102 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12103 Return a udev-rule file named @var{file-name} containing the rules
12104 defined by the @var{contents} literal.
12106 In the following example, a rule for a USB device is defined to be
12107 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12108 upon detecting a USB device with a given product identifier.
12111 (define %example-udev-rule
12113 "90-usb-thing.rules"
12114 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12115 "ATTR@{product@}==\"Example\", "
12116 "RUN+=\"/path/to/script\"")))
12119 The @command{herd rules udev} command, as root, returns the name of the
12120 directory containing all the active udev rules.
12123 Here we show how the default @var{udev-service} can be extended with it.
12129 (modify-services %desktop-services
12130 (udev-service-type config =>
12131 (udev-configuration (inherit config)
12132 (rules (append (udev-configuration-rules config)
12133 (list %example-udev-rule))))))))
12136 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12137 Return a udev file named @var{file-name} containing the rules defined
12138 within @var{file}, a file-like object.
12140 The following example showcases how we can use an existing rule file.
12143 (use-modules (guix download) ;for url-fetch
12144 (guix packages) ;for origin
12147 (define %android-udev-rules
12149 "51-android-udev.rules"
12150 (let ((version "20170910"))
12153 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12154 "android-udev-rules/" version "/51-android.rules"))
12156 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12160 Additionally, Guix package definitions can be included in @var{rules} in
12161 order to extend the udev rules with the definitions found under their
12162 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12163 @var{file->udev-rule} example, we could have used the
12164 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12165 packages android)} module.
12167 The following example shows how to use the @var{android-udev-rules}
12168 package so that the Android tool @command{adb} can detect devices
12169 without root privileges. It also details how to create the
12170 @code{adbusers} group, which is required for the proper functioning of
12171 the rules defined within the @var{android-udev-rules} package. To
12172 create such a group, we must define it both as part of the
12173 @var{supplementary-groups} of our @var{user-account} declaration, as
12174 well as in the @var{groups} field of the @var{operating-system} record.
12177 (use-modules (gnu packages android) ;for android-udev-rules
12178 (gnu system shadow) ;for user-group
12183 (users (cons (user-acount
12185 (supplementary-groups
12186 '("adbusers" ;for adb
12187 "wheel" "netdev" "audio" "video"))
12190 (groups (cons (user-group (system? #t) (name "adbusers"))
12196 (modify-services %desktop-services
12199 (udev-configuration (inherit config)
12200 (rules (cons android-udev-rules
12201 (udev-configuration-rules config))))))))
12204 @defvr {Scheme Variable} urandom-seed-service-type
12205 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12206 when rebooting. It also tries to seed @file{/dev/urandom} from
12207 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12211 @defvr {Scheme Variable} %random-seed-file
12212 This is the name of the file where some random bytes are saved by
12213 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12214 It defaults to @file{/var/lib/random-seed}.
12219 @defvr {Scheme Variable} gpm-service-type
12220 This is the type of the service that runs GPM, the @dfn{general-purpose
12221 mouse daemon}, which provides mouse support to the Linux console. GPM
12222 allows users to use the mouse in the console, notably to select, copy,
12225 The value for services of this type must be a @code{gpm-configuration}
12226 (see below). This service is not part of @code{%base-services}.
12229 @deftp {Data Type} gpm-configuration
12230 Data type representing the configuration of GPM.
12233 @item @code{options} (default: @code{%default-gpm-options})
12234 Command-line options passed to @command{gpm}. The default set of
12235 options instruct @command{gpm} to listen to mouse events on
12236 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12239 @item @code{gpm} (default: @code{gpm})
12240 The GPM package to use.
12245 @anchor{guix-publish-service-type}
12246 @deffn {Scheme Variable} guix-publish-service-type
12247 This is the service type for @command{guix publish} (@pxref{Invoking
12248 guix publish}). Its value must be a @code{guix-publish-configuration}
12249 object, as described below.
12251 This assumes that @file{/etc/guix} already contains a signing key pair as
12252 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12253 archive}). If that is not the case, the service will fail to start.
12256 @deftp {Data Type} guix-publish-configuration
12257 Data type representing the configuration of the @code{guix publish}
12261 @item @code{guix} (default: @code{guix})
12262 The Guix package to use.
12264 @item @code{port} (default: @code{80})
12265 The TCP port to listen for connections.
12267 @item @code{host} (default: @code{"localhost"})
12268 The host (and thus, network interface) to listen to. Use
12269 @code{"0.0.0.0"} to listen on all the network interfaces.
12271 @item @code{compression} (default: @code{'(("gzip" 3))})
12272 This is a list of compression method/level tuple used when compressing
12273 substitutes. For example, to compress all substitutes with @emph{both} lzip
12274 at level 7 and gzip at level 9, write:
12277 '(("lzip" 7) ("gzip" 9))
12280 Level 9 achieves the best compression ratio at the expense of increased CPU
12281 usage, whereas level 1 achieves fast compression.
12283 An empty list disables compression altogether.
12285 @item @code{nar-path} (default: @code{"nar"})
12286 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12287 publish, @code{--nar-path}}, for details.
12289 @item @code{cache} (default: @code{#f})
12290 When it is @code{#f}, disable caching and instead generate archives on
12291 demand. Otherwise, this should be the name of a directory---e.g.,
12292 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12293 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12294 @option{--cache}}, for more information on the tradeoffs involved.
12296 @item @code{workers} (default: @code{#f})
12297 When it is an integer, this is the number of worker threads used for
12298 caching; when @code{#f}, the number of processors is used.
12299 @xref{Invoking guix publish, @option{--workers}}, for more information.
12301 @item @code{ttl} (default: @code{#f})
12302 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12303 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12304 for more information.
12308 @anchor{rngd-service}
12309 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12310 [#:device "/dev/hwrng"]
12311 Return a service that runs the @command{rngd} program from @var{rng-tools}
12312 to add @var{device} to the kernel's entropy pool. The service will fail if
12313 @var{device} does not exist.
12316 @anchor{pam-limits-service}
12317 @cindex session limits
12322 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12324 Return a service that installs a configuration file for the
12325 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12326 @code{pam_limits} module}. The procedure optionally takes a list of
12327 @code{pam-limits-entry} values, which can be used to specify
12328 @code{ulimit} limits and nice priority limits to user sessions.
12330 The following limits definition sets two hard and soft limits for all
12331 login sessions of users in the @code{realtime} group:
12334 (pam-limits-service
12336 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12337 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12340 The first entry increases the maximum realtime priority for
12341 non-privileged processes; the second entry lifts any restriction of the
12342 maximum address space that can be locked in memory. These settings are
12343 commonly used for real-time audio systems.
12346 @node Scheduled Job Execution
12347 @subsection Scheduled Job Execution
12351 @cindex scheduling jobs
12352 The @code{(gnu services mcron)} module provides an interface to
12353 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12354 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12355 Unix @command{cron} daemon; the main difference is that it is
12356 implemented in Guile Scheme, which provides a lot of flexibility when
12357 specifying the scheduling of jobs and their actions.
12359 The example below defines an operating system that runs the
12360 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12361 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12362 well as the @command{mkid} command on behalf of an unprivileged user
12363 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12364 gexps to introduce job definitions that are passed to mcron
12365 (@pxref{G-Expressions}).
12368 (use-modules (guix) (gnu) (gnu services mcron))
12369 (use-package-modules base idutils)
12371 (define updatedb-job
12372 ;; Run 'updatedb' at 3AM every day. Here we write the
12373 ;; job's action as a Scheme procedure.
12374 #~(job '(next-hour '(3))
12376 (execl (string-append #$findutils "/bin/updatedb")
12378 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12380 (define garbage-collector-job
12381 ;; Collect garbage 5 minutes after midnight every day.
12382 ;; The job's action is a shell command.
12383 #~(job "5 0 * * *" ;Vixie cron syntax
12386 (define idutils-job
12387 ;; Update the index database as user "charlie" at 12:15PM
12388 ;; and 19:15PM. This runs from the user's home directory.
12389 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12390 (string-append #$idutils "/bin/mkid src")
12395 (services (cons (service mcron-service-type
12396 (mcron-configuration
12397 (jobs (list garbage-collector-job
12403 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12404 for more information on mcron job specifications. Below is the
12405 reference of the mcron service.
12407 On a running system, you can use the @code{schedule} action of the service to
12408 visualize the mcron jobs that will be executed next:
12411 # herd schedule mcron
12415 The example above lists the next five tasks that will be executed, but you can
12416 also specify the number of tasks to display:
12419 # herd schedule mcron 10
12422 @defvr {Scheme Variable} mcron-service-type
12423 This is the type of the @code{mcron} service, whose value is an
12424 @code{mcron-configuration} object.
12426 This service type can be the target of a service extension that provides
12427 it additional job specifications (@pxref{Service Composition}). In
12428 other words, it is possible to define services that provide additional
12432 @deftp {Data Type} mcron-configuration
12433 Data type representing the configuration of mcron.
12436 @item @code{mcron} (default: @var{mcron})
12437 The mcron package to use.
12440 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12441 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12442 specifications,, mcron, GNU@tie{}mcron}).
12448 @subsection Log Rotation
12451 @cindex log rotation
12453 Log files such as those found in @file{/var/log} tend to grow endlessly,
12454 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12455 their contents in separate files, possibly compressed. The @code{(gnu
12456 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12457 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12459 The example below defines an operating system that provides log rotation
12460 with the default settings, for commonly encountered log files.
12463 (use-modules (guix) (gnu))
12464 (use-service-modules admin mcron)
12465 (use-package-modules base idutils)
12469 (services (cons (service rottlog-service-type)
12473 @defvr {Scheme Variable} rottlog-service-type
12474 This is the type of the Rottlog service, whose value is a
12475 @code{rottlog-configuration} object.
12477 Other services can extend this one with new @code{log-rotation} objects
12478 (see below), thereby augmenting the set of files to be rotated.
12480 This service type can define mcron jobs (@pxref{Scheduled Job
12481 Execution}) to run the rottlog service.
12484 @deftp {Data Type} rottlog-configuration
12485 Data type representing the configuration of rottlog.
12488 @item @code{rottlog} (default: @code{rottlog})
12489 The Rottlog package to use.
12491 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12492 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12493 rottlog, GNU Rot[t]log Manual}).
12495 @item @code{rotations} (default: @code{%default-rotations})
12496 A list of @code{log-rotation} objects as defined below.
12499 This is a list of gexps where each gexp corresponds to an mcron job
12500 specification (@pxref{Scheduled Job Execution}).
12504 @deftp {Data Type} log-rotation
12505 Data type representing the rotation of a group of log files.
12507 Taking an example from the Rottlog manual (@pxref{Period Related File
12508 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12514 (files '("/var/log/apache/*"))
12515 (options '("storedir apache-archives"
12521 The list of fields is as follows:
12524 @item @code{frequency} (default: @code{'weekly})
12525 The log rotation frequency, a symbol.
12528 The list of files or file glob patterns to rotate.
12530 @item @code{options} (default: @code{'()})
12531 The list of rottlog options for this rotation (@pxref{Configuration
12532 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12534 @item @code{post-rotate} (default: @code{#f})
12535 Either @code{#f} or a gexp to execute once the rotation has completed.
12539 @defvr {Scheme Variable} %default-rotations
12540 Specifies weekly rotation of @var{%rotated-files} and
12541 a couple of other files.
12544 @defvr {Scheme Variable} %rotated-files
12545 The list of syslog-controlled files to be rotated. By default it is:
12546 @code{'("/var/log/messages" "/var/log/secure")}.
12549 @node Networking Services
12550 @subsection Networking Services
12552 The @code{(gnu services networking)} module provides services to configure
12553 the network interface.
12555 @cindex DHCP, networking service
12556 @defvr {Scheme Variable} dhcp-client-service-type
12557 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12558 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12559 is the DHCP client package to use, @code{isc-dhcp} by default.
12562 @deffn {Scheme Procedure} dhcpd-service-type
12563 This type defines a service that runs a DHCP daemon. To create a
12564 service of this type, you must supply a @code{<dhcpd-configuration>}.
12568 (service dhcpd-service-type
12569 (dhcpd-configuration
12570 (config-file (local-file "my-dhcpd.conf"))
12571 (interfaces '("enp0s25"))))
12575 @deftp {Data Type} dhcpd-configuration
12577 @item @code{package} (default: @code{isc-dhcp})
12578 The package that provides the DHCP daemon. This package is expected to
12579 provide the daemon at @file{sbin/dhcpd} relative to its output
12580 directory. The default package is the
12581 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
12582 @item @code{config-file} (default: @code{#f})
12583 The configuration file to use. This is required. It will be passed to
12584 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12585 object (@pxref{G-Expressions, file-like objects}). See @code{man
12586 dhcpd.conf} for details on the configuration file syntax.
12587 @item @code{version} (default: @code{"4"})
12588 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12589 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12590 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12592 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12593 The run directory to use. At service activation time, this directory
12594 will be created if it does not exist.
12595 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12596 The PID file to use. This corresponds to the @code{-pf} option of
12597 @code{dhcpd}. See @code{man dhcpd} for details.
12598 @item @code{interfaces} (default: @code{'()})
12599 The names of the network interfaces on which dhcpd should listen for
12600 broadcasts. If this list is not empty, then its elements (which must be
12601 strings) will be appended to the @code{dhcpd} invocation when starting
12602 the daemon. It may not be necessary to explicitly specify any
12603 interfaces here; see @code{man dhcpd} for details.
12607 @defvr {Scheme Variable} static-networking-service-type
12608 This is the type for statically-configured network interfaces.
12609 @c TODO Document <static-networking> data structures.
12612 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12613 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12614 [#:requirement @code{'(udev)}]
12615 Return a service that starts @var{interface} with address @var{ip}. If
12616 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12617 it must be a string specifying the default network gateway. @var{requirement}
12618 can be used to declare a dependency on another service before configuring the
12621 This procedure can be called several times, one for each network
12622 interface of interest. Behind the scenes what it does is extend
12623 @code{static-networking-service-type} with additional network interfaces
12629 (static-networking-service "eno1" "192.168.1.82"
12630 #:gateway "192.168.1.2"
12631 #:name-servers '("192.168.1.2"))
12638 @cindex network management
12639 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12640 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12641 management daemon that aims to simplify wired and wireless networking.
12643 This service adds the @var{wicd} package to the global profile, providing
12644 several commands to interact with the daemon and configure networking:
12645 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12646 and @command{wicd-curses} user interfaces.
12649 @cindex ModemManager
12651 @defvr {Scheme Variable} modem-manager-service-type
12652 This is the service type for the
12653 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12654 service. The value for this service type is a
12655 @code{modem-manager-configuration} record.
12657 This service is part of @code{%desktop-services} (@pxref{Desktop
12661 @deftp {Data Type} modem-manager-configuration
12662 Data type representing the configuration of ModemManager.
12665 @item @code{modem-manager} (default: @code{modem-manager})
12666 The ModemManager package to use.
12671 @cindex USB_ModeSwitch
12672 @cindex Modeswitching
12674 @defvr {Scheme Variable} usb-modeswitch-service-type
12675 This is the service type for the
12676 @uref{http://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
12677 value for this service type is a @code{usb-modeswitch-configuration} record.
12679 When plugged in, some USB modems (and other USB devices) initially present
12680 themselves as a read-only storage medium and not as a modem. They need to be
12681 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
12682 installs udev rules to automatically modeswitch these devices when they are
12685 This service is part of @code{%desktop-services} (@pxref{Desktop
12689 @deftp {Data Type} usb-modeswitch-configuration
12690 Data type representing the configuration of USB_ModeSwitch.
12693 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
12694 The USB_ModeSwitch package providing the binaries for modeswitching.
12696 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
12697 The package providing the device data and udev rules file used by
12700 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
12701 Which config file to use for the USB_ModeSwitch dispatcher. By default the
12702 config file shipped with USB_ModeSwitch is used which disables logging to
12703 @file{/var/log} among other default settings. If set to @code{#f}, no config
12709 @cindex NetworkManager
12711 @defvr {Scheme Variable} network-manager-service-type
12712 This is the service type for the
12713 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12714 service. The value for this service type is a
12715 @code{network-manager-configuration} record.
12717 This service is part of @code{%desktop-services} (@pxref{Desktop
12721 @deftp {Data Type} network-manager-configuration
12722 Data type representing the configuration of NetworkManager.
12725 @item @code{network-manager} (default: @code{network-manager})
12726 The NetworkManager package to use.
12728 @item @code{dns} (default: @code{"default"})
12729 Processing mode for DNS, which affects how NetworkManager uses the
12730 @code{resolv.conf} configuration file.
12734 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12735 provided by currently active connections.
12738 NetworkManager will run @code{dnsmasq} as a local caching nameserver,
12739 using a "split DNS" configuration if you are connected to a VPN, and
12740 then update @code{resolv.conf} to point to the local nameserver.
12743 NetworkManager will not modify @code{resolv.conf}.
12746 @item @code{vpn-plugins} (default: @code{'()})
12747 This is the list of available plugins for virtual private networks
12748 (VPNs). An example of this is the @code{network-manager-openvpn}
12749 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12755 @deffn {Scheme Variable} connman-service-type
12756 This is the service type to run @url{https://01.org/connman,Connman},
12757 a network connection manager.
12759 Its value must be an
12760 @code{connman-configuration} record as in this example:
12763 (service connman-service-type
12764 (connman-configuration
12765 (disable-vpn? #t)))
12768 See below for details about @code{connman-configuration}.
12771 @deftp {Data Type} connman-configuration
12772 Data Type representing the configuration of connman.
12775 @item @code{connman} (default: @var{connman})
12776 The connman package to use.
12778 @item @code{disable-vpn?} (default: @code{#f})
12779 When true, disable connman's vpn plugin.
12783 @cindex WPA Supplicant
12784 @defvr {Scheme Variable} wpa-supplicant-service-type
12785 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12786 supplicant}, an authentication daemon required to authenticate against
12787 encrypted WiFi or ethernet networks.
12790 @deftp {Data Type} wpa-supplicant-configuration
12791 Data type representing the configuration of WPA Supplicant.
12793 It takes the following parameters:
12796 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12797 The WPA Supplicant package to use.
12799 @item @code{dbus?} (default: @code{#t})
12800 Whether to listen for requests on D-Bus.
12802 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12803 Where to store the PID file.
12805 @item @code{interface} (default: @code{#f})
12806 If this is set, it must specify the name of a network interface that
12807 WPA supplicant will control.
12809 @item @code{config-file} (default: @code{#f})
12810 Optional configuration file to use.
12812 @item @code{extra-options} (default: @code{'()})
12813 List of additional command-line arguments to pass to the daemon.
12818 @defvr {Scheme Variable} iptables-service-type
12819 This is the service type to set up an iptables configuration. iptables is a
12820 packet filtering framework supported by the Linux kernel. This service
12821 supports configuring iptables for both IPv4 and IPv6. A simple example
12822 configuration rejecting all incoming connections except those to the ssh port
12826 (service iptables-service-type
12827 (iptables-configuration
12828 (ipv4-rules (plain-file "iptables.rules" "*filter
12832 -A INPUT -p tcp --dport 22 -j ACCEPT
12833 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12836 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12840 -A INPUT -p tcp --dport 22 -j ACCEPT
12841 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12847 @deftp {Data Type} iptables-configuration
12848 The data type representing the configuration of iptables.
12851 @item @code{iptables} (default: @code{iptables})
12852 The iptables package that provides @code{iptables-restore} and
12853 @code{ip6tables-restore}.
12854 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12855 The iptables rules to use. It will be passed to @code{iptables-restore}.
12856 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12858 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12859 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12860 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12865 @cindex NTP (Network Time Protocol), service
12866 @cindex real time clock
12867 @defvr {Scheme Variable} ntp-service-type
12868 This is the type of the service running the @uref{http://www.ntp.org,
12869 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12870 system clock synchronized with that of the specified NTP servers.
12872 The value of this service is an @code{ntpd-configuration} object, as described
12876 @deftp {Data Type} ntp-configuration
12877 This is the data type for the NTP service configuration.
12880 @item @code{servers} (default: @code{%ntp-servers})
12881 This is the list of servers (host names) with which @command{ntpd} will be
12884 @item @code{allow-large-adjustment?} (default: @code{#f})
12885 This determines whether @command{ntpd} is allowed to make an initial
12886 adjustment of more than 1,000 seconds.
12888 @item @code{ntp} (default: @code{ntp})
12889 The NTP package to use.
12893 @defvr {Scheme Variable} %ntp-servers
12894 List of host names used as the default NTP servers. These are servers of the
12895 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
12899 @deffn {Scheme Procedure} openntpd-service-type
12900 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
12901 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
12902 clock synchronized with that of the given servers.
12906 openntpd-service-type
12907 (openntpd-configuration
12908 (listen-on '("127.0.0.1" "::1"))
12909 (sensor '("udcf0 correction 70000"))
12910 (constraint-from '("www.gnu.org"))
12911 (constraints-from '("https://www.google.com/"))
12912 (allow-large-adjustment? #t)))
12917 @deftp {Data Type} openntpd-configuration
12919 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
12920 The openntpd executable to use.
12921 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
12922 A list of local IP addresses or hostnames the ntpd daemon should listen on.
12923 @item @code{query-from} (default: @code{'()})
12924 A list of local IP address the ntpd daemon should use for outgoing queries.
12925 @item @code{sensor} (default: @code{'()})
12926 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
12927 will listen to each sensor that actually exists and ignore non-existent ones.
12928 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
12930 @item @code{server} (default: @var{%ntp-servers})
12931 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
12932 @item @code{servers} (default: @code{'()})
12933 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
12934 @item @code{constraint-from} (default: @code{'()})
12935 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
12936 This time information is not used for precision but acts as an authenticated
12937 constraint, thereby reducing the impact of unauthenticated NTP
12938 man-in-the-middle attacks.
12939 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
12941 @item @code{constraints-from} (default: @code{'()})
12942 As with constraint from, specify a list of URLs, IP addresses or hostnames of
12943 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
12944 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
12945 @item @code{allow-large-adjustment?} (default: @code{#f})
12946 Determines if @code{ntpd} is allowed to make an initial adjustment of more
12952 @deffn {Scheme variable} inetd-service-type
12953 This service runs the @command{inetd} (@pxref{inetd invocation,,,
12954 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
12955 connections on internet sockets, and lazily starts the specified server
12956 program when a connection is made on one of these sockets.
12958 The value of this service is an @code{inetd-configuration} object. The
12959 following example configures the @command{inetd} daemon to provide the
12960 built-in @command{echo} service, as well as an smtp service which
12961 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
12962 gateway @code{hostname}:
12967 (inetd-configuration
12971 (socket-type 'stream)
12978 (socket-type 'stream)
12982 (program (file-append openssh "/bin/ssh"))
12984 '("ssh" "-qT" "-i" "/path/to/ssh_key"
12985 "-W" "smtp-server:25" "user@@hostname")))))
12988 See below for more details about @code{inetd-configuration}.
12991 @deftp {Data Type} inetd-configuration
12992 Data type representing the configuration of @command{inetd}.
12995 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
12996 The @command{inetd} executable to use.
12998 @item @code{entries} (default: @code{'()})
12999 A list of @command{inetd} service entries. Each entry should be created
13000 by the @code{inetd-entry} constructor.
13004 @deftp {Data Type} inetd-entry
13005 Data type representing an entry in the @command{inetd} configuration.
13006 Each entry corresponds to a socket where @command{inetd} will listen for
13010 @item @code{node} (default: @code{#f})
13011 Optional string, a comma-separated list of local addresses
13012 @command{inetd} should use when listening for this service.
13013 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13014 description of all options.
13016 A string, the name must correspond to an entry in @code{/etc/services}.
13017 @item @code{socket-type}
13018 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13020 @item @code{protocol}
13021 A string, must correspond to an entry in @code{/etc/protocols}.
13022 @item @code{wait?} (default: @code{#t})
13023 Whether @command{inetd} should wait for the server to exit before
13024 listening to new service requests.
13026 A string containing the user (and, optionally, group) name of the user
13027 as whom the server should run. The group name can be specified in a
13028 suffix, separated by a colon or period, i.e.@: @code{"user"},
13029 @code{"user:group"} or @code{"user.group"}.
13030 @item @code{program} (default: @code{"internal"})
13031 The server program which will serve the requests, or @code{"internal"}
13032 if @command{inetd} should use a built-in service.
13033 @item @code{arguments} (default: @code{'()})
13034 A list strings or file-like objects, which are the server program's
13035 arguments, starting with the zeroth argument, i.e.@: the name of the
13036 program itself. For @command{inetd}'s internal services, this entry
13037 must be @code{'()} or @code{'("internal")}.
13040 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
13041 detailed discussion of each configuration field.
13045 @defvr {Scheme Variable} tor-service-type
13046 This is the type for a service that runs the @uref{https://torproject.org,
13047 Tor} anonymous networking daemon. The service is configured using a
13048 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
13049 @code{tor} unprivileged user, which is a member of the @code{tor} group.
13053 @deftp {Data Type} tor-configuration
13055 @item @code{tor} (default: @code{tor})
13056 The package that provides the Tor daemon. This package is expected to provide
13057 the daemon at @file{bin/tor} relative to its output directory. The default
13058 package is the @uref{https://www.torproject.org, Tor Project's}
13061 @item @code{config-file} (default: @code{(plain-file "empty" "")})
13062 The configuration file to use. It will be appended to a default configuration
13063 file, and the final configuration file will be passed to @code{tor} via its
13064 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
13065 file-like objects}). See @code{man tor} for details on the configuration file
13068 @item @code{hidden-services} (default: @code{'()})
13069 The list of @code{<hidden-service>} records to use. For any hidden service
13070 you include in this list, appropriate configuration to enable the hidden
13071 service will be automatically added to the default configuration file. You
13072 may conveniently create @code{<hidden-service>} records using the
13073 @code{tor-hidden-service} procedure described below.
13075 @item @code{socks-socket-type} (default: @code{'tcp})
13076 The default socket type that Tor should use for its SOCKS socket. This must
13077 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
13078 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
13079 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
13080 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
13083 If you want to customize the SOCKS socket in more detail, leave
13084 @code{socks-socket-type} at its default value of @code{'tcp} and use
13085 @code{config-file} to override the default by providing your own
13086 @code{SocksPort} option.
13090 @cindex hidden service
13091 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
13092 Define a new Tor @dfn{hidden service} called @var{name} and implementing
13093 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
13096 '((22 "127.0.0.1:22")
13097 (80 "127.0.0.1:8080"))
13100 In this example, port 22 of the hidden service is mapped to local port 22, and
13101 port 80 is mapped to local port 8080.
13103 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13104 the @file{hostname} file contains the @code{.onion} host name for the hidden
13107 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13108 project's documentation} for more information.
13111 The @code{(gnu services rsync)} module provides the following services:
13113 You might want an rsync daemon if you have files that you want available
13114 so anyone (or just yourself) can download existing files or upload new
13117 @deffn {Scheme Variable} rsync-service-type
13118 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13119 The value for this service type is a
13120 @command{rsync-configuration} record as in this example:
13123 (service rsync-service-type)
13126 See below for details about @code{rsync-configuration}.
13129 @deftp {Data Type} rsync-configuration
13130 Data type representing the configuration for @code{rsync-service}.
13133 @item @code{package} (default: @var{rsync})
13134 @code{rsync} package to use.
13136 @item @code{port-number} (default: @code{873})
13137 TCP port on which @command{rsync} listens for incoming connections. If port
13138 is less than @code{1024} @command{rsync} needs to be started as the
13139 @code{root} user and group.
13141 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13142 Name of the file where @command{rsync} writes its PID.
13144 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13145 Name of the file where @command{rsync} writes its lock file.
13147 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13148 Name of the file where @command{rsync} writes its log file.
13150 @item @code{use-chroot?} (default: @var{#t})
13151 Whether to use chroot for @command{rsync} shared directory.
13153 @item @code{share-path} (default: @file{/srv/rsync})
13154 Location of the @command{rsync} shared directory.
13156 @item @code{share-comment} (default: @code{"Rsync share"})
13157 Comment of the @command{rsync} shared directory.
13159 @item @code{read-only?} (default: @var{#f})
13160 Read-write permissions to shared directory.
13162 @item @code{timeout} (default: @code{300})
13163 I/O timeout in seconds.
13165 @item @code{user} (default: @var{"root"})
13166 Owner of the @code{rsync} process.
13168 @item @code{group} (default: @var{"root"})
13169 Group of the @code{rsync} process.
13171 @item @code{uid} (default: @var{"rsyncd"})
13172 User name or user ID that file transfers to and from that module should take
13173 place as when the daemon was run as @code{root}.
13175 @item @code{gid} (default: @var{"rsyncd"})
13176 Group name or group ID that will be used when accessing the module.
13181 Furthermore, @code{(gnu services ssh)} provides the following services.
13185 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13186 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13187 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13188 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13189 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13190 [#:public-key-authentication? #t] [#:initialize? #t]
13191 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13192 @var{host-key} must designate a file containing the host key, and readable
13195 When @var{daemonic?} is true, @command{lshd} will detach from the
13196 controlling terminal and log its output to syslogd, unless one sets
13197 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13198 depend on existence of syslogd service. When @var{pid-file?} is true,
13199 @command{lshd} writes its PID to the file called @var{pid-file}.
13201 When @var{initialize?} is true, automatically create the seed and host key
13202 upon service activation if they do not exist yet. This may take long and
13203 require interaction.
13205 When @var{initialize?} is false, it is up to the user to initialize the
13206 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13207 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13208 basics,,, lsh, LSH Manual}).
13210 When @var{interfaces} is empty, lshd listens for connections on all the
13211 network interfaces; otherwise, @var{interfaces} must be a list of host names
13214 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13215 passwords, and @var{root-login?} specifies whether to accept log-ins as
13218 The other options should be self-descriptive.
13223 @deffn {Scheme Variable} openssh-service-type
13224 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13225 shell daemon, @command{sshd}. Its value must be an
13226 @code{openssh-configuration} record as in this example:
13229 (service openssh-service-type
13230 (openssh-configuration
13231 (x11-forwarding? #t)
13232 (permit-root-login 'without-password)
13234 `(("alice" ,(local-file "alice.pub"))
13235 ("bob" ,(local-file "bob.pub"))))))
13238 See below for details about @code{openssh-configuration}.
13240 This service can be extended with extra authorized keys, as in this
13244 (service-extension openssh-service-type
13245 (const `(("charlie"
13246 ,(local-file "charlie.pub")))))
13250 @deftp {Data Type} openssh-configuration
13251 This is the configuration record for OpenSSH's @command{sshd}.
13254 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13255 Name of the file where @command{sshd} writes its PID.
13257 @item @code{port-number} (default: @code{22})
13258 TCP port on which @command{sshd} listens for incoming connections.
13260 @item @code{permit-root-login} (default: @code{#f})
13261 This field determines whether and when to allow logins as root. If
13262 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13263 If it's the symbol @code{'without-password}, then root logins are
13264 permitted but not with password-based authentication.
13266 @item @code{allow-empty-passwords?} (default: @code{#f})
13267 When true, users with empty passwords may log in. When false, they may
13270 @item @code{password-authentication?} (default: @code{#t})
13271 When true, users may log in with their password. When false, they have
13272 other authentication methods.
13274 @item @code{public-key-authentication?} (default: @code{#t})
13275 When true, users may log in using public key authentication. When
13276 false, users have to use other authentication method.
13278 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13279 This is used only by protocol version 2.
13281 @item @code{x11-forwarding?} (default: @code{#f})
13282 When true, forwarding of X11 graphical client connections is
13283 enabled---in other words, @command{ssh} options @option{-X} and
13284 @option{-Y} will work.
13286 @item @code{allow-agent-forwarding?} (default: @code{#t})
13287 Whether to allow agent forwarding.
13289 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13290 Whether to allow TCP forwarding.
13292 @item @code{gateway-ports?} (default: @code{#f})
13293 Whether to allow gateway ports.
13295 @item @code{challenge-response-authentication?} (default: @code{#f})
13296 Specifies whether challenge response authentication is allowed (e.g.@: via
13299 @item @code{use-pam?} (default: @code{#t})
13300 Enables the Pluggable Authentication Module interface. If set to
13301 @code{#t}, this will enable PAM authentication using
13302 @code{challenge-response-authentication?} and
13303 @code{password-authentication?}, in addition to PAM account and session
13304 module processing for all authentication types.
13306 Because PAM challenge response authentication usually serves an
13307 equivalent role to password authentication, you should disable either
13308 @code{challenge-response-authentication?} or
13309 @code{password-authentication?}.
13311 @item @code{print-last-log?} (default: @code{#t})
13312 Specifies whether @command{sshd} should print the date and time of the
13313 last user login when a user logs in interactively.
13315 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13316 Configures external subsystems (e.g.@: file transfer daemon).
13318 This is a list of two-element lists, each of which containing the
13319 subsystem name and a command (with optional arguments) to execute upon
13322 The command @command{internal-sftp} implements an in-process SFTP
13323 server. Alternately, one can specify the @command{sftp-server} command:
13325 (service openssh-service-type
13326 (openssh-configuration
13328 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13331 @item @code{accepted-environment} (default: @code{'()})
13332 List of strings describing which environment variables may be exported.
13334 Each string gets on its own line. See the @code{AcceptEnv} option in
13335 @code{man sshd_config}.
13337 This example allows ssh-clients to export the @code{COLORTERM} variable.
13338 It is set by terminal emulators, which support colors. You can use it in
13339 your shell's ressource file to enable colors for the prompt and commands
13340 if this variable is set.
13343 (service openssh-service-type
13344 (openssh-configuration
13345 (accepted-environment '("COLORTERM"))))
13348 @item @code{authorized-keys} (default: @code{'()})
13349 @cindex authorized keys, SSH
13350 @cindex SSH authorized keys
13351 This is the list of authorized keys. Each element of the list is a user
13352 name followed by one or more file-like objects that represent SSH public
13356 (openssh-configuration
13358 `(("rekado" ,(local-file "rekado.pub"))
13359 ("chris" ,(local-file "chris.pub"))
13360 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13364 registers the specified public keys for user accounts @code{rekado},
13365 @code{chris}, and @code{root}.
13367 Additional authorized keys can be specified @i{via}
13368 @code{service-extension}.
13370 Note that this does @emph{not} interfere with the use of
13371 @file{~/.ssh/authorized_keys}.
13373 @item @code{log-level} (default: @code{'info})
13374 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13375 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13376 page for @file{sshd_config} for the full list of level names.
13378 @item @code{extra-content} (default: @code{""})
13379 This field can be used to append arbitrary text to the configuration file. It
13380 is especially useful for elaborate configurations that cannot be expressed
13381 otherwise. This configuration, for example, would generally disable root
13382 logins, but permit them from one specific IP address:
13385 (openssh-configuration
13387 Match Address 192.168.0.1
13388 PermitRootLogin yes"))
13394 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13395 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13396 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13399 For example, to specify a Dropbear service listening on port 1234, add
13400 this call to the operating system's @code{services} field:
13403 (dropbear-service (dropbear-configuration
13404 (port-number 1234)))
13408 @deftp {Data Type} dropbear-configuration
13409 This data type represents the configuration of a Dropbear SSH daemon.
13412 @item @code{dropbear} (default: @var{dropbear})
13413 The Dropbear package to use.
13415 @item @code{port-number} (default: 22)
13416 The TCP port where the daemon waits for incoming connections.
13418 @item @code{syslog-output?} (default: @code{#t})
13419 Whether to enable syslog output.
13421 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13422 File name of the daemon's PID file.
13424 @item @code{root-login?} (default: @code{#f})
13425 Whether to allow @code{root} logins.
13427 @item @code{allow-empty-passwords?} (default: @code{#f})
13428 Whether to allow empty passwords.
13430 @item @code{password-authentication?} (default: @code{#t})
13431 Whether to enable password-based authentication.
13435 @defvr {Scheme Variable} %facebook-host-aliases
13436 This variable contains a string for use in @file{/etc/hosts}
13437 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13438 line contains a entry that maps a known server name of the Facebook
13439 on-line service---e.g., @code{www.facebook.com}---to the local
13440 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13442 This variable is typically used in the @code{hosts-file} field of an
13443 @code{operating-system} declaration (@pxref{operating-system Reference,
13444 @file{/etc/hosts}}):
13447 (use-modules (gnu) (guix))
13450 (host-name "mymachine")
13453 ;; Create a /etc/hosts file with aliases for "localhost"
13454 ;; and "mymachine", as well as for Facebook servers.
13455 (plain-file "hosts"
13456 (string-append (local-host-aliases host-name)
13457 %facebook-host-aliases))))
13460 This mechanism can prevent programs running locally, such as Web
13461 browsers, from accessing Facebook.
13464 The @code{(gnu services avahi)} provides the following definition.
13466 @defvr {Scheme Variable} avahi-service-type
13467 This is the service that runs @command{avahi-daemon}, a system-wide
13468 mDNS/DNS-SD responder that allows for service discovery and
13469 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
13470 Its value must be a @code{zero-configuration} record---see below.
13472 This service extends the name service cache daemon (nscd) so that it can
13473 resolve @code{.local} host names using
13474 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13475 Service Switch}, for information on host name resolution.
13477 Additionally, add the @var{avahi} package to the system profile so that
13478 commands such as @command{avahi-browse} are directly usable.
13481 @deftp {Data Type} avahi-configuration
13482 Data type representation the configuration for Avahi.
13486 @item @code{host-name} (default: @code{#f})
13487 If different from @code{#f}, use that as the host name to
13488 publish for this machine; otherwise, use the machine's actual host name.
13490 @item @code{publish?} (default: @code{#t})
13491 When true, allow host names and services to be published (broadcast) over the
13494 @item @code{publish-workstation?} (default: @code{#t})
13495 When true, @command{avahi-daemon} publishes the machine's host name and IP
13496 address via mDNS on the local network. To view the host names published on
13497 your local network, you can run:
13500 avahi-browse _workstation._tcp
13503 @item @code{wide-area?} (default: @code{#f})
13504 When true, DNS-SD over unicast DNS is enabled.
13506 @item @code{ipv4?} (default: @code{#t})
13507 @itemx @code{ipv6?} (default: @code{#t})
13508 These fields determine whether to use IPv4/IPv6 sockets.
13510 @item @code{domains-to-browse} (default: @code{'()})
13511 This is a list of domains to browse.
13515 @deffn {Scheme Variable} openvswitch-service-type
13516 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
13517 service, whose value should be an @code{openvswitch-configuration}
13521 @deftp {Data Type} openvswitch-configuration
13522 Data type representing the configuration of Open vSwitch, a multilayer
13523 virtual switch which is designed to enable massive network automation
13524 through programmatic extension.
13527 @item @code{package} (default: @var{openvswitch})
13528 Package object of the Open vSwitch.
13534 @subsection X Window
13537 @cindex X Window System
13538 @cindex login manager
13539 Support for the X Window graphical display system---specifically
13540 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13541 there is no @code{xorg-service} procedure. Instead, the X server is
13542 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
13545 @cindex GNOME, login manager
13546 GDM of course allows users to log in into window managers and desktop
13547 environments other than GNOME; for those using GNOME, GDM is required for
13548 features such as automatic screen locking.
13550 @cindex window manager
13551 To use X11, you must install at least one @dfn{window manager}---for
13552 example the @code{windowmaker} or @code{openbox} packages---preferably
13553 by adding it to the @code{packages} field of your operating system
13554 definition (@pxref{operating-system Reference, system-wide packages}).
13556 @defvr {Scheme Variable} gdm-service-type
13557 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
13558 Desktop Manager} (GDM), a program that manages graphical display servers and
13559 handles graphical user logins. Its value must be a @code{gdm-configuration}
13562 @cindex session types (X11)
13563 @cindex X11 session types
13564 GDM looks for @dfn{session types} described by the @file{.desktop} files in
13565 @file{/run/current-system/profile/share/xsessions} and allows users to choose
13566 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
13567 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
13568 set of packages automatically makes them available at the log-in screen.
13570 In addition, @file{~/.xsession} files are honored. When available,
13571 @file{~/.xsession} must be an executable that starts a window manager
13572 and/or other X clients.
13575 @deftp {Data Type} gdm-configuration
13577 @item @code{auto-login?} (default: @code{#f})
13578 @itemx @code{default-user} (default: @code{#f})
13579 When @code{auto-login?} is false, GDM presents a log-in screen.
13581 When @code{auto-login?} is true, GDM logs in directly as
13582 @code{default-user}.
13584 @item @code{gnome-shell-assets} (default: ...)
13585 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
13587 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
13588 Configuration of the Xorg graphical server.
13590 @item @code{xsession} (default: @code{(xinitrc)})
13591 Script to run before starting a X session.
13593 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
13594 File name of the @code{dbus-daemon} executable.
13596 @item @code{gdm} (default: @code{gdm})
13597 The GDM package to use.
13601 @defvr {Scheme Variable} slim-service-type
13602 This is the type for the SLiM graphical login manager for X11.
13604 Like GDM, SLiM looks for session types described by @file{.desktop} files and
13605 allows users to choose a session from the log-in screen using @kbd{F1}. It
13606 also honors @file{~/.xsession} files.
13608 Unlike GDM, SLiM does not spawn the user session on a different VT after
13609 logging in, which means that you can only start one graphical session. If you
13610 want to be able to run multiple graphical sessions at the same time you have
13611 to add multiple SLiM services to your system services. The following example
13612 shows how to replace the default GDM service with two SLiM services on tty7
13616 (use-modules (gnu services)
13617 (gnu services desktop)
13618 (gnu services xorg)
13619 (srfi srfi-1)) ;for 'remove'
13623 (services (cons* (service slim-service-type (slim-configuration
13626 (service slim-service-type (slim-configuration
13629 (remove (lambda (service)
13630 (eq? (service-kind service) gdm-service-type))
13631 %desktop-services))))
13636 @deftp {Data Type} slim-configuration
13637 Data type representing the configuration of @code{slim-service-type}.
13640 @item @code{allow-empty-passwords?} (default: @code{#t})
13641 Whether to allow logins with empty passwords.
13643 @item @code{auto-login?} (default: @code{#f})
13644 @itemx @code{default-user} (default: @code{""})
13645 When @code{auto-login?} is false, SLiM presents a log-in screen.
13647 When @code{auto-login?} is true, SLiM logs in directly as
13648 @code{default-user}.
13650 @item @code{theme} (default: @code{%default-slim-theme})
13651 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13652 The graphical theme to use and its name.
13654 @item @code{auto-login-session} (default: @code{#f})
13655 If true, this must be the name of the executable to start as the default
13656 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13658 If false, a session described by one of the available @file{.desktop}
13659 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13663 You must install at least one window manager in the system profile or in
13664 your user profile. Failing to do that, if @code{auto-login-session} is
13665 false, you will be unable to log in.
13668 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13669 Configuration of the Xorg graphical server.
13671 @item @code{display} (default @code{":0"})
13672 The display on which to start the Xorg graphical server.
13674 @item @code{vt} (default @code{"vt7"})
13675 The VT on which to start the Xorg graphical server.
13677 @item @code{xauth} (default: @code{xauth})
13678 The XAuth package to use.
13680 @item @code{shepherd} (default: @code{shepherd})
13681 The Shepherd package used when invoking @command{halt} and
13684 @item @code{sessreg} (default: @code{sessreg})
13685 The sessreg package used in order to register the session.
13687 @item @code{slim} (default: @code{slim})
13688 The SLiM package to use.
13692 @defvr {Scheme Variable} %default-theme
13693 @defvrx {Scheme Variable} %default-theme-name
13694 The default SLiM theme and its name.
13698 @deftp {Data Type} sddm-configuration
13699 This is the data type representing the sddm service configuration.
13702 @item @code{display-server} (default: "x11")
13703 Select display server to use for the greeter. Valid values are "x11"
13706 @item @code{numlock} (default: "on")
13707 Valid values are "on", "off" or "none".
13709 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13710 Command to run when halting.
13712 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13713 Command to run when rebooting.
13715 @item @code{theme} (default "maldives")
13716 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13718 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13719 Directory to look for themes.
13721 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13722 Directory to look for faces.
13724 @item @code{default-path} (default "/run/current-system/profile/bin")
13725 Default PATH to use.
13727 @item @code{minimum-uid} (default: 1000)
13728 Minimum UID displayed in SDDM and allowed for log-in.
13730 @item @code{maximum-uid} (default: 2000)
13731 Maximum UID to display in SDDM.
13733 @item @code{remember-last-user?} (default #t)
13734 Remember last user.
13736 @item @code{remember-last-session?} (default #t)
13737 Remember last session.
13739 @item @code{hide-users} (default "")
13740 Usernames to hide from SDDM greeter.
13742 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13743 Users with shells listed will be hidden from the SDDM greeter.
13745 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13746 Script to run before starting a wayland session.
13748 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13749 Directory to look for desktop files starting wayland sessions.
13751 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13752 Configuration of the Xorg graphical server.
13754 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13757 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13760 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13761 Script to run after starting xorg-server.
13763 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13764 Script to run before stopping xorg-server.
13766 @item @code{xsession-command} (default: @code{xinitrc})
13767 Script to run before starting a X session.
13769 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13770 Directory to look for desktop files starting X sessions.
13772 @item @code{minimum-vt} (default: 7)
13775 @item @code{auto-login-user} (default "")
13776 User to use for auto-login.
13778 @item @code{auto-login-session} (default "")
13779 Desktop file to use for auto-login.
13781 @item @code{relogin?} (default #f)
13782 Relogin after logout.
13787 @cindex login manager
13789 @deffn {Scheme Procedure} sddm-service config
13790 Return a service that spawns the SDDM graphical login manager for config of
13791 type @code{<sddm-configuration>}.
13794 (sddm-service (sddm-configuration
13795 (auto-login-user "Alice")
13796 (auto-login-session "xfce.desktop")))
13800 @cindex Xorg, configuration
13801 @deftp {Data Type} xorg-configuration
13802 This data type represents the configuration of the Xorg graphical display
13803 server. Note that there is not Xorg service; instead, the X server is started
13804 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13805 of these display managers aggregates an @code{xorg-configuration} record.
13808 @item @code{modules} (default: @code{%default-xorg-modules})
13809 This is a list of @dfn{module packages} loaded by the Xorg
13810 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13812 @item @code{fonts} (default: @code{%default-xorg-fonts})
13813 This is a list of font directories to add to the server's @dfn{font path}.
13815 @item @code{drivers} (default: @code{'()})
13816 This must be either the empty list, in which case Xorg chooses a graphics
13817 driver automatically, or a list of driver names that will be tried in this
13818 order---e.g., @code{("modesetting" "vesa")}.
13820 @item @code{resolutions} (default: @code{'()})
13821 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13822 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13825 @cindex keyboard layout, for Xorg
13826 @cindex keymap, for Xorg
13827 @item @code{keyboard-layout} (default: @code{#f})
13828 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13829 English (``qwerty'') for a 105-key PC keyboard.
13831 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13832 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
13833 information on how to specify the keyboard layout.
13835 @item @code{extra-config} (default: @code{'()})
13836 This is a list of strings or objects appended to the configuration file. It
13837 is used to pass extra text to be added verbatim to the configuration file.
13839 @item @code{server} (default: @code{xorg-server})
13840 This is the package providing the Xorg server.
13842 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13843 This is the list of command-line arguments to pass to the X server. The
13844 default is @code{-nolisten tcp}.
13848 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
13849 [@var{login-manager-service-type}]
13850 Tell the log-in manager (of type @var{login-manager-service-type}) to use
13851 @var{config}, an @code{<xorg-configuration>} record.
13853 Since the Xorg configuration is embedded in the log-in manager's
13854 configuration---e.g., @code{gdm-configuration}---this procedure provides a
13855 shorthand to set the Xorg configuration.
13858 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13859 Return a @code{startx} script in which the modules, fonts, etc. specified
13860 in @var{config}, are available. The result should be used in place of
13863 Usually the X server is started by a login manager.
13867 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13868 Add @var{package}, a package for a screen locker or screen saver whose
13869 command is @var{program}, to the set of setuid programs and add a PAM entry
13870 for it. For example:
13873 (screen-locker-service xlockmore "xlock")
13876 makes the good ol' XlockMore usable.
13880 @node Printing Services
13881 @subsection Printing Services
13883 @cindex printer support with CUPS
13884 The @code{(gnu services cups)} module provides a Guix service definition
13885 for the CUPS printing service. To add printer support to a Guix
13886 system, add a @code{cups-service} to the operating system definition:
13888 @deffn {Scheme Variable} cups-service-type
13889 The service type for the CUPS print server. Its value should be a valid
13890 CUPS configuration (see below). To use the default settings, simply
13893 (service cups-service-type)
13897 The CUPS configuration controls the basic things about your CUPS
13898 installation: what interfaces it listens on, what to do if a print job
13899 fails, how much logging to do, and so on. To actually add a printer,
13900 you have to visit the @url{http://localhost:631} URL, or use a tool such
13901 as GNOME's printer configuration services. By default, configuring a
13902 CUPS service will generate a self-signed certificate if needed, for
13903 secure connections to the print server.
13905 Suppose you want to enable the Web interface of CUPS and also add
13906 support for Epson printers @i{via} the @code{escpr} package and for HP
13907 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
13908 like this (you need to use the @code{(gnu packages cups)} module):
13911 (service cups-service-type
13912 (cups-configuration
13913 (web-interface? #t)
13915 (list cups-filters escpr hplip-minimal))))
13918 Note: If you wish to use the Qt5 based GUI which comes with the hplip
13919 package then it is suggested that you install the @code{hplip} package,
13920 either in your OS configuration file or as your user.
13922 The available configuration parameters follow. Each parameter
13923 definition is preceded by its type; for example, @samp{string-list foo}
13924 indicates that the @code{foo} parameter should be specified as a list of
13925 strings. There is also a way to specify the configuration as a string,
13926 if you have an old @code{cupsd.conf} file that you want to port over
13927 from some other system; see the end for more details.
13929 @c The following documentation was initially generated by
13930 @c (generate-documentation) in (gnu services cups). Manually maintained
13931 @c documentation is better, so we shouldn't hesitate to edit below as
13932 @c needed. However if the change you want to make to this documentation
13933 @c can be done in an automated way, it's probably easier to change
13934 @c (generate-documentation) than to make it below and have to deal with
13935 @c the churn as CUPS updates.
13938 Available @code{cups-configuration} fields are:
13940 @deftypevr {@code{cups-configuration} parameter} package cups
13944 @deftypevr {@code{cups-configuration} parameter} package-list extensions
13945 Drivers and other extensions to the CUPS package.
13948 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
13949 Configuration of where to write logs, what directories to use for print
13950 spools, and related privileged configuration parameters.
13952 Available @code{files-configuration} fields are:
13954 @deftypevr {@code{files-configuration} parameter} log-location access-log
13955 Defines the access log filename. Specifying a blank filename disables
13956 access log generation. The value @code{stderr} causes log entries to be
13957 sent to the standard error file when the scheduler is running in the
13958 foreground, or to the system log daemon when run in the background. The
13959 value @code{syslog} causes log entries to be sent to the system log
13960 daemon. The server name may be included in filenames using the string
13961 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
13963 Defaults to @samp{"/var/log/cups/access_log"}.
13966 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
13967 Where CUPS should cache data.
13969 Defaults to @samp{"/var/cache/cups"}.
13972 @deftypevr {@code{files-configuration} parameter} string config-file-perm
13973 Specifies the permissions for all configuration files that the scheduler
13976 Note that the permissions for the printers.conf file are currently
13977 masked to only allow access from the scheduler user (typically root).
13978 This is done because printer device URIs sometimes contain sensitive
13979 authentication information that should not be generally known on the
13980 system. There is no way to disable this security feature.
13982 Defaults to @samp{"0640"}.
13985 @deftypevr {@code{files-configuration} parameter} log-location error-log
13986 Defines the error log filename. Specifying a blank filename disables
13987 error log generation. The value @code{stderr} causes log entries to be
13988 sent to the standard error file when the scheduler is running in the
13989 foreground, or to the system log daemon when run in the background. The
13990 value @code{syslog} causes log entries to be sent to the system log
13991 daemon. The server name may be included in filenames using the string
13992 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
13994 Defaults to @samp{"/var/log/cups/error_log"}.
13997 @deftypevr {@code{files-configuration} parameter} string fatal-errors
13998 Specifies which errors are fatal, causing the scheduler to exit. The
14003 No errors are fatal.
14006 All of the errors below are fatal.
14009 Browsing initialization errors are fatal, for example failed connections
14010 to the DNS-SD daemon.
14013 Configuration file syntax errors are fatal.
14016 Listen or Port errors are fatal, except for IPv6 failures on the
14017 loopback or @code{any} addresses.
14020 Log file creation or write errors are fatal.
14023 Bad startup file permissions are fatal, for example shared TLS
14024 certificate and key files with world-read permissions.
14027 Defaults to @samp{"all -browse"}.
14030 @deftypevr {@code{files-configuration} parameter} boolean file-device?
14031 Specifies whether the file pseudo-device can be used for new printer
14032 queues. The URI @uref{file:///dev/null} is always allowed.
14034 Defaults to @samp{#f}.
14037 @deftypevr {@code{files-configuration} parameter} string group
14038 Specifies the group name or ID that will be used when executing external
14041 Defaults to @samp{"lp"}.
14044 @deftypevr {@code{files-configuration} parameter} string log-file-perm
14045 Specifies the permissions for all log files that the scheduler writes.
14047 Defaults to @samp{"0644"}.
14050 @deftypevr {@code{files-configuration} parameter} log-location page-log
14051 Defines the page log filename. Specifying a blank filename disables
14052 page log generation. The value @code{stderr} causes log entries to be
14053 sent to the standard error file when the scheduler is running in the
14054 foreground, or to the system log daemon when run in the background. The
14055 value @code{syslog} causes log entries to be sent to the system log
14056 daemon. The server name may be included in filenames using the string
14057 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
14059 Defaults to @samp{"/var/log/cups/page_log"}.
14062 @deftypevr {@code{files-configuration} parameter} string remote-root
14063 Specifies the username that is associated with unauthenticated accesses
14064 by clients claiming to be the root user. The default is @code{remroot}.
14066 Defaults to @samp{"remroot"}.
14069 @deftypevr {@code{files-configuration} parameter} file-name request-root
14070 Specifies the directory that contains print jobs and other HTTP request
14073 Defaults to @samp{"/var/spool/cups"}.
14076 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
14077 Specifies the level of security sandboxing that is applied to print
14078 filters, backends, and other child processes of the scheduler; either
14079 @code{relaxed} or @code{strict}. This directive is currently only
14080 used/supported on macOS.
14082 Defaults to @samp{strict}.
14085 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
14086 Specifies the location of TLS certificates and private keys. CUPS will
14087 look for public and private keys in this directory: a @code{.crt} files
14088 for PEM-encoded certificates and corresponding @code{.key} files for
14089 PEM-encoded private keys.
14091 Defaults to @samp{"/etc/cups/ssl"}.
14094 @deftypevr {@code{files-configuration} parameter} file-name server-root
14095 Specifies the directory containing the server configuration files.
14097 Defaults to @samp{"/etc/cups"}.
14100 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14101 Specifies whether the scheduler calls fsync(2) after writing
14102 configuration or state files.
14104 Defaults to @samp{#f}.
14107 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14108 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14111 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14112 Specifies the directory where temporary files are stored.
14114 Defaults to @samp{"/var/spool/cups/tmp"}.
14117 @deftypevr {@code{files-configuration} parameter} string user
14118 Specifies the user name or ID that is used when running external
14121 Defaults to @samp{"lp"}.
14125 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14126 Specifies the logging level for the AccessLog file. The @code{config}
14127 level logs when printers and classes are added, deleted, or modified and
14128 when configuration files are accessed or updated. The @code{actions}
14129 level logs when print jobs are submitted, held, released, modified, or
14130 canceled, and any of the conditions for @code{config}. The @code{all}
14131 level logs all requests.
14133 Defaults to @samp{actions}.
14136 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14137 Specifies whether to purge job history data automatically when it is no
14138 longer required for quotas.
14140 Defaults to @samp{#f}.
14143 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14144 Specifies which protocols to use for local printer sharing.
14146 Defaults to @samp{dnssd}.
14149 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14150 Specifies whether the CUPS web interface is advertised.
14152 Defaults to @samp{#f}.
14155 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14156 Specifies whether shared printers are advertised.
14158 Defaults to @samp{#f}.
14161 @deftypevr {@code{cups-configuration} parameter} string classification
14162 Specifies the security classification of the server. Any valid banner
14163 name can be used, including "classified", "confidential", "secret",
14164 "topsecret", and "unclassified", or the banner can be omitted to disable
14165 secure printing functions.
14167 Defaults to @samp{""}.
14170 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14171 Specifies whether users may override the classification (cover page) of
14172 individual print jobs using the @code{job-sheets} option.
14174 Defaults to @samp{#f}.
14177 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14178 Specifies the default type of authentication to use.
14180 Defaults to @samp{Basic}.
14183 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14184 Specifies whether encryption will be used for authenticated requests.
14186 Defaults to @samp{Required}.
14189 @deftypevr {@code{cups-configuration} parameter} string default-language
14190 Specifies the default language to use for text and web content.
14192 Defaults to @samp{"en"}.
14195 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14196 Specifies the default paper size for new print queues. @samp{"Auto"}
14197 uses a locale-specific default, while @samp{"None"} specifies there is
14198 no default paper size. Specific size names are typically
14199 @samp{"Letter"} or @samp{"A4"}.
14201 Defaults to @samp{"Auto"}.
14204 @deftypevr {@code{cups-configuration} parameter} string default-policy
14205 Specifies the default access policy to use.
14207 Defaults to @samp{"default"}.
14210 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14211 Specifies whether local printers are shared by default.
14213 Defaults to @samp{#t}.
14216 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14217 Specifies the delay for updating of configuration and state files, in
14218 seconds. A value of 0 causes the update to happen as soon as possible,
14219 typically within a few milliseconds.
14221 Defaults to @samp{30}.
14224 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14225 Specifies what to do when an error occurs. Possible values are
14226 @code{abort-job}, which will discard the failed print job;
14227 @code{retry-job}, which will retry the job at a later time;
14228 @code{retry-this-job}, which retries the failed job immediately; and
14229 @code{stop-printer}, which stops the printer.
14231 Defaults to @samp{stop-printer}.
14234 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14235 Specifies the maximum cost of filters that are run concurrently, which
14236 can be used to minimize disk, memory, and CPU resource problems. A
14237 limit of 0 disables filter limiting. An average print to a
14238 non-PostScript printer needs a filter limit of about 200. A PostScript
14239 printer needs about half that (100). Setting the limit below these
14240 thresholds will effectively limit the scheduler to printing a single job
14243 Defaults to @samp{0}.
14246 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14247 Specifies the scheduling priority of filters that are run to print a
14248 job. The nice value ranges from 0, the highest priority, to 19, the
14251 Defaults to @samp{0}.
14254 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14255 Specifies whether to do reverse lookups on connecting clients. The
14256 @code{double} setting causes @code{cupsd} to verify that the hostname
14257 resolved from the address matches one of the addresses returned for that
14258 hostname. Double lookups also prevent clients with unregistered
14259 addresses from connecting to your server. Only set this option to
14260 @code{#t} or @code{double} if absolutely required.
14262 Defaults to @samp{#f}.
14265 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14266 Specifies the number of seconds to wait before killing the filters and
14267 backend associated with a canceled or held job.
14269 Defaults to @samp{30}.
14272 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14273 Specifies the interval between retries of jobs in seconds. This is
14274 typically used for fax queues but can also be used with normal print
14275 queues whose error policy is @code{retry-job} or
14276 @code{retry-current-job}.
14278 Defaults to @samp{30}.
14281 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14282 Specifies the number of retries that are done for jobs. This is
14283 typically used for fax queues but can also be used with normal print
14284 queues whose error policy is @code{retry-job} or
14285 @code{retry-current-job}.
14287 Defaults to @samp{5}.
14290 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14291 Specifies whether to support HTTP keep-alive connections.
14293 Defaults to @samp{#t}.
14296 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14297 Specifies how long an idle client connection remains open, in seconds.
14299 Defaults to @samp{30}.
14302 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14303 Specifies the maximum size of print files, IPP requests, and HTML form
14304 data. A limit of 0 disables the limit check.
14306 Defaults to @samp{0}.
14309 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14310 Listens on the specified interfaces for connections. Valid values are
14311 of the form @var{address}:@var{port}, where @var{address} is either an
14312 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14313 indicate all addresses. Values can also be file names of local UNIX
14314 domain sockets. The Listen directive is similar to the Port directive
14315 but allows you to restrict access to specific interfaces or networks.
14318 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14319 Specifies the number of pending connections that will be allowed. This
14320 normally only affects very busy servers that have reached the MaxClients
14321 limit, but can also be triggered by large numbers of simultaneous
14322 connections. When the limit is reached, the operating system will
14323 refuse additional connections until the scheduler can accept the pending
14326 Defaults to @samp{128}.
14329 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14330 Specifies a set of additional access controls.
14332 Available @code{location-access-controls} fields are:
14334 @deftypevr {@code{location-access-controls} parameter} file-name path
14335 Specifies the URI path to which the access control applies.
14338 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14339 Access controls for all access to this path, in the same format as the
14340 @code{access-controls} of @code{operation-access-control}.
14342 Defaults to @samp{()}.
14345 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14346 Access controls for method-specific access to this path.
14348 Defaults to @samp{()}.
14350 Available @code{method-access-controls} fields are:
14352 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14353 If @code{#t}, apply access controls to all methods except the listed
14354 methods. Otherwise apply to only the listed methods.
14356 Defaults to @samp{#f}.
14359 @deftypevr {@code{method-access-controls} parameter} method-list methods
14360 Methods to which this access control applies.
14362 Defaults to @samp{()}.
14365 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14366 Access control directives, as a list of strings. Each string should be
14367 one directive, such as "Order allow,deny".
14369 Defaults to @samp{()}.
14374 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14375 Specifies the number of debugging messages that are retained for logging
14376 if an error occurs in a print job. Debug messages are logged regardless
14377 of the LogLevel setting.
14379 Defaults to @samp{100}.
14382 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14383 Specifies the level of logging for the ErrorLog file. The value
14384 @code{none} stops all logging while @code{debug2} logs everything.
14386 Defaults to @samp{info}.
14389 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14390 Specifies the format of the date and time in the log files. The value
14391 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14393 Defaults to @samp{standard}.
14396 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
14397 Specifies the maximum number of simultaneous clients that are allowed by
14400 Defaults to @samp{100}.
14403 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
14404 Specifies the maximum number of simultaneous clients that are allowed
14405 from a single address.
14407 Defaults to @samp{100}.
14410 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
14411 Specifies the maximum number of copies that a user can print of each
14414 Defaults to @samp{9999}.
14417 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
14418 Specifies the maximum time a job may remain in the @code{indefinite}
14419 hold state before it is canceled. A value of 0 disables cancellation of
14422 Defaults to @samp{0}.
14425 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14426 Specifies the maximum number of simultaneous jobs that are allowed. Set
14427 to 0 to allow an unlimited number of jobs.
14429 Defaults to @samp{500}.
14432 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14433 Specifies the maximum number of simultaneous jobs that are allowed per
14434 printer. A value of 0 allows up to MaxJobs jobs per printer.
14436 Defaults to @samp{0}.
14439 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14440 Specifies the maximum number of simultaneous jobs that are allowed per
14441 user. A value of 0 allows up to MaxJobs jobs per user.
14443 Defaults to @samp{0}.
14446 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14447 Specifies the maximum time a job may take to print before it is
14448 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14450 Defaults to @samp{10800}.
14453 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14454 Specifies the maximum size of the log files before they are rotated, in
14455 bytes. The value 0 disables log rotation.
14457 Defaults to @samp{1048576}.
14460 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14461 Specifies the maximum amount of time to allow between files in a
14462 multiple file print job, in seconds.
14464 Defaults to @samp{300}.
14467 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14468 Specifies the format of PageLog lines. Sequences beginning with percent
14469 (@samp{%}) characters are replaced with the corresponding information,
14470 while all other characters are copied literally. The following percent
14471 sequences are recognized:
14475 insert a single percent character
14478 insert the value of the specified IPP attribute
14481 insert the number of copies for the current page
14484 insert the current page number
14487 insert the current date and time in common log format
14493 insert the printer name
14496 insert the username
14499 A value of the empty string disables page logging. The string @code{%p
14500 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14501 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14504 Defaults to @samp{""}.
14507 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14508 Passes the specified environment variable(s) to child processes; a list
14511 Defaults to @samp{()}.
14514 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14515 Specifies named access control policies.
14517 Available @code{policy-configuration} fields are:
14519 @deftypevr {@code{policy-configuration} parameter} string name
14520 Name of the policy.
14523 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14524 Specifies an access list for a job's private values. @code{@@ACL} maps
14525 to the printer's requesting-user-name-allowed or
14526 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14527 owner. @code{@@SYSTEM} maps to the groups listed for the
14528 @code{system-group} field of the @code{files-config} configuration,
14529 which is reified into the @code{cups-files.conf(5)} file. Other
14530 possible elements of the access list include specific user names, and
14531 @code{@@@var{group}} to indicate members of a specific group. The
14532 access list may also be simply @code{all} or @code{default}.
14534 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14537 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14538 Specifies the list of job values to make private, or @code{all},
14539 @code{default}, or @code{none}.
14541 Defaults to @samp{"job-name job-originating-host-name
14542 job-originating-user-name phone"}.
14545 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14546 Specifies an access list for a subscription's private values.
14547 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14548 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14549 owner. @code{@@SYSTEM} maps to the groups listed for the
14550 @code{system-group} field of the @code{files-config} configuration,
14551 which is reified into the @code{cups-files.conf(5)} file. Other
14552 possible elements of the access list include specific user names, and
14553 @code{@@@var{group}} to indicate members of a specific group. The
14554 access list may also be simply @code{all} or @code{default}.
14556 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14559 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14560 Specifies the list of job values to make private, or @code{all},
14561 @code{default}, or @code{none}.
14563 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14564 notify-subscriber-user-name notify-user-data"}.
14567 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14568 Access control by IPP operation.
14570 Defaults to @samp{()}.
14574 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14575 Specifies whether job files (documents) are preserved after a job is
14576 printed. If a numeric value is specified, job files are preserved for
14577 the indicated number of seconds after printing. Otherwise a boolean
14578 value applies indefinitely.
14580 Defaults to @samp{86400}.
14583 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14584 Specifies whether the job history is preserved after a job is printed.
14585 If a numeric value is specified, the job history is preserved for the
14586 indicated number of seconds after printing. If @code{#t}, the job
14587 history is preserved until the MaxJobs limit is reached.
14589 Defaults to @samp{#t}.
14592 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14593 Specifies the amount of time to wait for job completion before
14594 restarting the scheduler.
14596 Defaults to @samp{30}.
14599 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14600 Specifies the maximum amount of memory to use when converting documents
14601 into bitmaps for a printer.
14603 Defaults to @samp{"128m"}.
14606 @deftypevr {@code{cups-configuration} parameter} string server-admin
14607 Specifies the email address of the server administrator.
14609 Defaults to @samp{"root@@localhost.localdomain"}.
14612 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14613 The ServerAlias directive is used for HTTP Host header validation when
14614 clients connect to the scheduler from external interfaces. Using the
14615 special name @code{*} can expose your system to known browser-based DNS
14616 rebinding attacks, even when accessing sites through a firewall. If the
14617 auto-discovery of alternate names does not work, we recommend listing
14618 each alternate name with a ServerAlias directive instead of using
14621 Defaults to @samp{*}.
14624 @deftypevr {@code{cups-configuration} parameter} string server-name
14625 Specifies the fully-qualified host name of the server.
14627 Defaults to @samp{"localhost"}.
14630 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14631 Specifies what information is included in the Server header of HTTP
14632 responses. @code{None} disables the Server header. @code{ProductOnly}
14633 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14634 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14635 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14636 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14637 2.0.0 (@var{uname}) IPP/2.0}.
14639 Defaults to @samp{Minimal}.
14642 @deftypevr {@code{cups-configuration} parameter} string set-env
14643 Set the specified environment variable to be passed to child processes.
14645 Defaults to @samp{"variable value"}.
14648 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14649 Listens on the specified interfaces for encrypted connections. Valid
14650 values are of the form @var{address}:@var{port}, where @var{address} is
14651 either an IPv6 address enclosed in brackets, an IPv4 address, or
14652 @code{*} to indicate all addresses.
14654 Defaults to @samp{()}.
14657 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14658 Sets encryption options. By default, CUPS only supports encryption
14659 using TLS v1.0 or higher using known secure cipher suites. The
14660 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14661 required for some older clients that do not implement newer ones. The
14662 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14663 older clients that do not support TLS v1.0.
14665 Defaults to @samp{()}.
14668 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14669 Specifies whether the scheduler requires clients to strictly adhere to
14670 the IPP specifications.
14672 Defaults to @samp{#f}.
14675 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14676 Specifies the HTTP request timeout, in seconds.
14678 Defaults to @samp{300}.
14682 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14683 Specifies whether the web interface is enabled.
14685 Defaults to @samp{#f}.
14688 At this point you're probably thinking ``oh dear, Guix manual, I like
14689 you but you can stop already with the configuration options''. Indeed.
14690 However, one more point: it could be that you have an existing
14691 @code{cupsd.conf} that you want to use. In that case, you can pass an
14692 @code{opaque-cups-configuration} as the configuration of a
14693 @code{cups-service-type}.
14695 Available @code{opaque-cups-configuration} fields are:
14697 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14701 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14702 The contents of the @code{cupsd.conf}, as a string.
14705 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14706 The contents of the @code{cups-files.conf} file, as a string.
14709 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14710 strings of the same name, you could instantiate a CUPS service like
14714 (service cups-service-type
14715 (opaque-cups-configuration
14716 (cupsd.conf cupsd.conf)
14717 (cups-files.conf cups-files.conf)))
14721 @node Desktop Services
14722 @subsection Desktop Services
14724 The @code{(gnu services desktop)} module provides services that are
14725 usually useful in the context of a ``desktop'' setup---that is, on a
14726 machine running a graphical display server, possibly with graphical user
14727 interfaces, etc. It also defines services that provide specific desktop
14728 environments like GNOME, Xfce or MATE.
14730 To simplify things, the module defines a variable containing the set of
14731 services that users typically expect on a machine with a graphical
14732 environment and networking:
14734 @defvr {Scheme Variable} %desktop-services
14735 This is a list of services that builds upon @code{%base-services} and
14736 adds or adjusts services for a typical ``desktop'' setup.
14738 In particular, it adds a graphical login manager (@pxref{X Window,
14739 @code{gdm-service-type}}), screen lockers, a network management tool
14740 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
14741 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
14742 energy and color management services, the @code{elogind} login and seat
14743 manager, the Polkit privilege service, the GeoClue location service, the
14744 AccountsService daemon that allows authorized users change system passwords,
14745 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
14746 name service switch service configured to be able to use @code{nss-mdns}
14747 (@pxref{Name Service Switch, mDNS}).
14750 The @code{%desktop-services} variable can be used as the @code{services}
14751 field of an @code{operating-system} declaration (@pxref{operating-system
14752 Reference, @code{services}}).
14754 Additionally, the @code{gnome-desktop-service-type},
14755 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14756 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
14757 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14758 services like the backlight adjustment helpers and the power management
14759 utilities are added to the system, extending @code{polkit} and @code{dbus}
14760 appropriately, allowing GNOME to operate with elevated privileges on a
14761 limited number of special-purpose system interfaces. Additionally,
14762 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
14763 metapackage to the system profile. Likewise, adding the Xfce service
14764 not only adds the @code{xfce} metapackage to the system profile, but it
14765 also gives the Thunar file manager the ability to open a ``root-mode''
14766 file management window, if the user authenticates using the
14767 administrator's password via the standard polkit graphical interface.
14768 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14769 appropriately, allowing MATE to operate with elevated privileges on a
14770 limited number of special-purpose system interfaces. Additionally,
14771 adding a service of type @code{mate-desktop-service-type} adds the MATE
14772 metapackage to the system profile. ``Adding Enlightenment'' means that
14773 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14774 are set as setuid, allowing Enlightenment's screen locker and other
14775 functionality to work as expetected.
14777 The desktop environments in Guix use the Xorg display server by
14778 default. If you'd like to use the newer display server protocol
14779 called Wayland, you need to use the @code{sddm-service} instead of
14780 GDM as the graphical login manager. You should then
14781 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14782 also try starting GNOME on Wayland manually from a TTY with the
14783 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14784 gnome-session``. Currently only GNOME has support for Wayland.
14786 @defvr {Scheme Variable} gnome-desktop-service-type
14787 This is the type of the service that adds the @uref{https://www.gnome.org,
14788 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
14789 object (see below.)
14791 This service adds the @code{gnome} package to the system profile, and extends
14792 polkit with the actions from @code{gnome-settings-daemon}.
14795 @deftp {Data Type} gnome-desktop-configuration
14796 Configuration record for the GNOME desktop environment.
14799 @item @code{gnome} (default: @code{gnome})
14800 The GNOME package to use.
14804 @defvr {Scheme Variable} xfce-desktop-service-type
14805 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
14806 desktop environment. Its value is an @code{xfce-desktop-configuration} object
14809 This service adds the @code{xfce} package to the system profile, and
14810 extends polkit with the ability for @code{thunar} to manipulate the file
14811 system as root from within a user session, after the user has authenticated
14812 with the administrator's password.
14815 @deftp {Data Type} xfce-desktop-configuration
14816 Configuration record for the Xfce desktop environment.
14819 @item @code{xfce} (default: @code{xfce})
14820 The Xfce package to use.
14824 @deffn {Scheme Variable} mate-desktop-service-type
14825 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14826 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14827 object (see below.)
14829 This service adds the @code{mate} package to the system
14830 profile, and extends polkit with the actions from
14831 @code{mate-settings-daemon}.
14834 @deftp {Data Type} mate-desktop-configuration
14835 Configuration record for the MATE desktop environment.
14838 @item @code{mate} (default: @code{mate})
14839 The MATE package to use.
14843 @deffn {Scheme Variable} enlightenment-desktop-service-type
14844 Return a service that adds the @code{enlightenment} package to the system
14845 profile, and extends dbus with actions from @code{efl}.
14848 @deftp {Data Type} enlightenment-desktop-service-configuration
14850 @item @code{enlightenment} (default: @code{enlightenment})
14851 The enlightenment package to use.
14855 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
14856 the default @code{%desktop-services} variable doesn't include any of
14857 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
14858 @code{%desktop-services} in the @code{services} field of your
14859 @code{operating-system}:
14862 (use-modules (gnu))
14863 (use-service-modules desktop)
14866 ;; cons* adds items to the list given as its last argument.
14867 (services (cons* (service gnome-desktop-service-type)
14868 (service xfce-desktop-service)
14869 %desktop-services))
14873 These desktop environments will then be available as options in the
14874 graphical login window.
14876 The actual service definitions included in @code{%desktop-services} and
14877 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14878 are described below.
14880 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14881 Return a service that runs the ``system bus'', using @var{dbus}, with
14882 support for @var{services}.
14884 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14885 facility. Its system bus is used to allow system services to communicate
14886 and to be notified of system-wide events.
14888 @var{services} must be a list of packages that provide an
14889 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14890 and policy files. For example, to allow avahi-daemon to use the system bus,
14891 @var{services} must be equal to @code{(list avahi)}.
14894 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14895 Return a service that runs the @code{elogind} login and
14896 seat management daemon. @uref{https://github.com/elogind/elogind,
14897 Elogind} exposes a D-Bus interface that can be used to know which users
14898 are logged in, know what kind of sessions they have open, suspend the
14899 system, inhibit system suspend, reboot the system, and other tasks.
14901 Elogind handles most system-level power events for a computer, for
14902 example suspending the system when a lid is closed, or shutting it down
14903 when the power button is pressed.
14905 The @var{config} keyword argument specifies the configuration for
14906 elogind, and should be the result of an @code{(elogind-configuration
14907 (@var{parameter} @var{value})...)} invocation. Available parameters and
14908 their default values are:
14911 @item kill-user-processes?
14913 @item kill-only-users
14915 @item kill-exclude-users
14917 @item inhibit-delay-max-seconds
14919 @item handle-power-key
14921 @item handle-suspend-key
14923 @item handle-hibernate-key
14925 @item handle-lid-switch
14927 @item handle-lid-switch-docked
14929 @item power-key-ignore-inhibited?
14931 @item suspend-key-ignore-inhibited?
14933 @item hibernate-key-ignore-inhibited?
14935 @item lid-switch-ignore-inhibited?
14937 @item holdoff-timeout-seconds
14941 @item idle-action-seconds
14943 @item runtime-directory-size-percent
14945 @item runtime-directory-size
14949 @item suspend-state
14950 @code{("mem" "standby" "freeze")}
14953 @item hibernate-state
14955 @item hibernate-mode
14956 @code{("platform" "shutdown")}
14957 @item hybrid-sleep-state
14959 @item hybrid-sleep-mode
14960 @code{("suspend" "platform" "shutdown")}
14964 @deffn {Scheme Procedure} accountsservice-service @
14965 [#:accountsservice @var{accountsservice}]
14966 Return a service that runs AccountsService, a system service that can
14967 list available accounts, change their passwords, and so on.
14968 AccountsService integrates with PolicyKit to enable unprivileged users
14969 to acquire the capability to modify their system configuration.
14970 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
14971 accountsservice web site} for more information.
14973 The @var{accountsservice} keyword argument is the @code{accountsservice}
14974 package to expose as a service.
14977 @deffn {Scheme Procedure} polkit-service @
14978 [#:polkit @var{polkit}]
14979 Return a service that runs the
14980 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
14981 management service}, which allows system administrators to grant access to
14982 privileged operations in a structured way. By querying the Polkit service, a
14983 privileged system component can know when it should grant additional
14984 capabilities to ordinary users. For example, an ordinary user can be granted
14985 the capability to suspend the system if the user is logged in locally.
14988 @defvr {Scheme Variable} upower-service-type
14989 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
14990 system-wide monitor for power consumption and battery levels, with the given
14991 configuration settings.
14993 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
14994 notably used by GNOME.
14997 @deftp {Data Type} upower-configuration
14998 Data type representation the configuration for UPower.
15002 @item @code{upower} (default: @var{upower})
15003 Package to use for @code{upower}.
15005 @item @code{watts-up-pro?} (default: @code{#f})
15006 Enable the Watts Up Pro device.
15008 @item @code{poll-batteries?} (default: @code{#t})
15009 Enable polling the kernel for battery level changes.
15011 @item @code{ignore-lid?} (default: @code{#f})
15012 Ignore the lid state, this can be useful if it's incorrect on a device.
15014 @item @code{use-percentage-for-policy?} (default: @code{#f})
15015 Whether battery percentage based policy should be used. The default is to use
15016 the time left, change to @code{#t} to use the percentage.
15018 @item @code{percentage-low} (default: @code{10})
15019 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15020 at which the battery is considered low.
15022 @item @code{percentage-critical} (default: @code{3})
15023 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15024 at which the battery is considered critical.
15026 @item @code{percentage-action} (default: @code{2})
15027 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15028 at which action will be taken.
15030 @item @code{time-low} (default: @code{1200})
15031 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15032 seconds at which the battery is considered low.
15034 @item @code{time-critical} (default: @code{300})
15035 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15036 seconds at which the battery is considered critical.
15038 @item @code{time-action} (default: @code{120})
15039 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15040 seconds at which action will be taken.
15042 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
15043 The action taken when @code{percentage-action} or @code{time-action} is
15044 reached (depending on the configuration of @code{use-percentage-for-policy?}).
15046 Possible values are:
15056 @code{'hybrid-sleep}.
15062 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
15063 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
15064 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
15065 notifications and ways to mount/unmount disks. Programs that talk to UDisks
15066 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
15069 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
15070 Return a service that runs @command{colord}, a system service with a D-Bus
15071 interface to manage the color profiles of input and output devices such as
15072 screens and scanners. It is notably used by the GNOME Color Manager graphical
15073 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
15074 site} for more information.
15077 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
15078 Return a configuration allowing an application to access GeoClue
15079 location data. @var{name} is the Desktop ID of the application, without
15080 the @code{.desktop} part. If @var{allowed?} is true, the application
15081 will have access to location information by default. The boolean
15082 @var{system?} value indicates whether an application is a system component
15083 or not. Finally @var{users} is a list of UIDs of all users for which
15084 this application is allowed location info access. An empty users list
15085 means that all users are allowed.
15088 @defvr {Scheme Variable} %standard-geoclue-applications
15089 The standard list of well-known GeoClue application configurations,
15090 granting authority to the GNOME date-and-time utility to ask for the
15091 current location in order to set the time zone, and allowing the
15092 IceCat and Epiphany web browsers to request location information.
15093 IceCat and Epiphany both query the user before allowing a web page to
15094 know the user's location.
15097 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
15098 [#:whitelist '()] @
15099 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
15100 [#:submit-data? #f]
15101 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15102 [#:submission-nick "geoclue"] @
15103 [#:applications %standard-geoclue-applications]
15104 Return a service that runs the GeoClue location service. This service
15105 provides a D-Bus interface to allow applications to request access to a
15106 user's physical location, and optionally to add information to online
15107 location databases. See
15108 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
15109 web site} for more information.
15112 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
15113 [@w{#:auto-enable? #f}]
15114 Return a service that runs the @command{bluetoothd} daemon, which
15115 manages all the Bluetooth devices and provides a number of D-Bus
15116 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15117 powered automatically at boot, which can be useful when using a
15118 bluetooth keyboard or mouse.
15120 Users need to be in the @code{lp} group to access the D-Bus service.
15123 @node Sound Services
15124 @subsection Sound Services
15126 @cindex sound support
15128 @cindex PulseAudio, sound support
15130 The @code{(gnu services sound)} module provides a service to configure the
15131 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15132 preferred ALSA output driver.
15134 @deffn {Scheme Variable} alsa-service-type
15135 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15136 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15137 configuration file. The value for this type is a @command{alsa-configuration}
15138 record as in this example:
15141 (service alsa-service-type)
15144 See below for details about @code{alsa-configuration}.
15147 @deftp {Data Type} alsa-configuration
15148 Data type representing the configuration for @code{alsa-service}.
15151 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15152 @code{alsa-plugins} package to use.
15154 @item @code{pulseaudio?} (default: @var{#t})
15155 Whether ALSA applications should transparently be made to use the
15156 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15158 Using PulseAudio allows you to run several sound-producing applications
15159 at the same time and to individual control them @i{via}
15160 @command{pavucontrol}, among other things.
15162 @item @code{extra-options} (default: @var{""})
15163 String to append to the @file{/etc/asound.conf} file.
15168 Individual users who want to override the system configuration of ALSA can do
15169 it with the @file{~/.asoundrc} file:
15172 # In guix, we have to specify the absolute path for plugins.
15174 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15177 # Routing ALSA to jack:
15178 # <http://jackaudio.org/faq/routing_alsa.html>.
15182 0 system:playback_1
15183 1 system:playback_2
15200 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15204 @node Database Services
15205 @subsection Database Services
15209 The @code{(gnu services databases)} module provides the following services.
15211 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15212 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15213 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15214 Return a service that runs @var{postgresql}, the PostgreSQL database
15217 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15218 creates a database cluster with @var{locale} as the default
15219 locale, stored in @var{data-directory}. It then listens on @var{port}.
15221 @cindex postgresql extension-packages
15222 Additional extensions are loaded from packages listed in
15223 @var{extension-packages}. Extensions are available at runtime. For instance,
15224 to create a geographic database using the @code{postgis} extension, a user can
15225 configure the postgresql-service as in this example:
15229 (use-package-modules databases geo)
15233 ;; postgresql is required to run `psql' but postgis is not required for
15234 ;; proper operation.
15235 (packages (cons* postgresql %base-packages))
15238 (postgresql-service #:extension-packages (list postgis))
15242 Then the extension becomes visible and you can initialise an empty geographic
15243 database in this way:
15247 > create database postgistest;
15248 > \connect postgistest;
15249 > create extension postgis;
15250 > create extension postgis_topology;
15253 There is no need to add this field for contrib extensions such as hstore or
15254 dblink as they are already loadable by postgresql. This field is only
15255 required to add extensions provided by other packages.
15258 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15259 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15262 The optional @var{config} argument specifies the configuration for
15263 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15266 @deftp {Data Type} mysql-configuration
15267 Data type representing the configuration of @var{mysql-service}.
15270 @item @code{mysql} (default: @var{mariadb})
15271 Package object of the MySQL database server, can be either @var{mariadb}
15274 For MySQL, a temporary root password will be displayed at activation time.
15275 For MariaDB, the root password is empty.
15277 @item @code{port} (default: @code{3306})
15278 TCP port on which the database server listens for incoming connections.
15282 @defvr {Scheme Variable} memcached-service-type
15283 This is the service type for the @uref{https://memcached.org/,
15284 Memcached} service, which provides a distributed in memory cache. The
15285 value for the service type is a @code{memcached-configuration} object.
15289 (service memcached-service-type)
15292 @deftp {Data Type} memcached-configuration
15293 Data type representing the configuration of memcached.
15296 @item @code{memcached} (default: @code{memcached})
15297 The Memcached package to use.
15299 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15300 Network interfaces on which to listen.
15302 @item @code{tcp-port} (default: @code{11211})
15303 Port on which to accept connections on,
15305 @item @code{udp-port} (default: @code{11211})
15306 Port on which to accept UDP connections on, a value of 0 will disable
15307 listening on a UDP socket.
15309 @item @code{additional-options} (default: @code{'()})
15310 Additional command line options to pass to @code{memcached}.
15314 @defvr {Scheme Variable} mongodb-service-type
15315 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15316 The value for the service type is a @code{mongodb-configuration} object.
15320 (service mongodb-service-type)
15323 @deftp {Data Type} mongodb-configuration
15324 Data type representing the configuration of mongodb.
15327 @item @code{mongodb} (default: @code{mongodb})
15328 The MongoDB package to use.
15330 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15331 The configuration file for MongoDB.
15333 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15334 This value is used to create the directory, so that it exists and is
15335 owned by the mongodb user. It should match the data-directory which
15336 MongoDB is configured to use through the configuration file.
15340 @defvr {Scheme Variable} redis-service-type
15341 This is the service type for the @uref{https://redis.io/, Redis}
15342 key/value store, whose value is a @code{redis-configuration} object.
15345 @deftp {Data Type} redis-configuration
15346 Data type representing the configuration of redis.
15349 @item @code{redis} (default: @code{redis})
15350 The Redis package to use.
15352 @item @code{bind} (default: @code{"127.0.0.1"})
15353 Network interface on which to listen.
15355 @item @code{port} (default: @code{6379})
15356 Port on which to accept connections on, a value of 0 will disable
15357 listening on a TCP socket.
15359 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15360 Directory in which to store the database and related files.
15364 @node Mail Services
15365 @subsection Mail Services
15369 The @code{(gnu services mail)} module provides Guix service definitions
15370 for email services: IMAP, POP3, and LMTP servers, as well as mail
15371 transport agents (MTAs). Lots of acronyms! These services are detailed
15372 in the subsections below.
15374 @subsubheading Dovecot Service
15376 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15377 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15380 By default, Dovecot does not need much configuration; the default
15381 configuration object created by @code{(dovecot-configuration)} will
15382 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15383 certificate will be generated for TLS-protected connections, though
15384 Dovecot will also listen on cleartext ports by default. There are a
15385 number of options, though, which mail administrators might need to change,
15386 and as is the case with other services, Guix allows the system
15387 administrator to specify these parameters via a uniform Scheme interface.
15389 For example, to specify that mail is located at @code{maildir~/.mail},
15390 one would instantiate the Dovecot service like this:
15393 (dovecot-service #:config
15394 (dovecot-configuration
15395 (mail-location "maildir:~/.mail")))
15398 The available configuration parameters follow. Each parameter
15399 definition is preceded by its type; for example, @samp{string-list foo}
15400 indicates that the @code{foo} parameter should be specified as a list of
15401 strings. There is also a way to specify the configuration as a string,
15402 if you have an old @code{dovecot.conf} file that you want to port over
15403 from some other system; see the end for more details.
15405 @c The following documentation was initially generated by
15406 @c (generate-documentation) in (gnu services mail). Manually maintained
15407 @c documentation is better, so we shouldn't hesitate to edit below as
15408 @c needed. However if the change you want to make to this documentation
15409 @c can be done in an automated way, it's probably easier to change
15410 @c (generate-documentation) than to make it below and have to deal with
15411 @c the churn as dovecot updates.
15413 Available @code{dovecot-configuration} fields are:
15415 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
15416 The dovecot package.
15419 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
15420 A list of IPs or hosts where to listen for connections. @samp{*}
15421 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
15422 interfaces. If you want to specify non-default ports or anything more
15423 complex, customize the address and port fields of the
15424 @samp{inet-listener} of the specific services you are interested in.
15427 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
15428 List of protocols we want to serve. Available protocols include
15429 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
15431 Available @code{protocol-configuration} fields are:
15433 @deftypevr {@code{protocol-configuration} parameter} string name
15434 The name of the protocol.
15437 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
15438 UNIX socket path to the master authentication server to find users.
15439 This is used by imap (for shared users) and lda.
15440 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15443 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
15444 Space separated list of plugins to load.
15447 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
15448 Maximum number of IMAP connections allowed for a user from each IP
15449 address. NOTE: The username is compared case-sensitively.
15450 Defaults to @samp{10}.
15455 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15456 List of services to enable. Available services include @samp{imap},
15457 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15460 Available @code{service-configuration} fields are:
15462 @deftypevr {@code{service-configuration} parameter} string kind
15463 The service kind. Valid values include @code{director},
15464 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15465 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15466 @code{tcpwrap}, @code{quota-warning}, or anything else.
15469 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15470 Listeners for the service. A listener is either a
15471 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15472 an @code{inet-listener-configuration}.
15473 Defaults to @samp{()}.
15475 Available @code{unix-listener-configuration} fields are:
15477 @deftypevr {@code{unix-listener-configuration} parameter} string path
15478 Path to the file, relative to @code{base-dir} field. This is also used as
15482 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15483 The access mode for the socket.
15484 Defaults to @samp{"0600"}.
15487 @deftypevr {@code{unix-listener-configuration} parameter} string user
15488 The user to own the socket.
15489 Defaults to @samp{""}.
15492 @deftypevr {@code{unix-listener-configuration} parameter} string group
15493 The group to own the socket.
15494 Defaults to @samp{""}.
15498 Available @code{fifo-listener-configuration} fields are:
15500 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15501 Path to the file, relative to @code{base-dir} field. This is also used as
15505 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15506 The access mode for the socket.
15507 Defaults to @samp{"0600"}.
15510 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15511 The user to own the socket.
15512 Defaults to @samp{""}.
15515 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15516 The group to own the socket.
15517 Defaults to @samp{""}.
15521 Available @code{inet-listener-configuration} fields are:
15523 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15524 The protocol to listen for.
15527 @deftypevr {@code{inet-listener-configuration} parameter} string address
15528 The address on which to listen, or empty for all addresses.
15529 Defaults to @samp{""}.
15532 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15533 The port on which to listen.
15536 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15537 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15539 Defaults to @samp{#t}.
15544 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15545 Maximum number of simultaneous client connections per process. Once
15546 this number of connections is received, the next incoming connection
15547 will prompt Dovecot to spawn another process. If set to 0,
15548 @code{default-client-limit} is used instead.
15550 Defaults to @samp{0}.
15554 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15555 Number of connections to handle before starting a new process.
15556 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15557 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15558 Defaults to @samp{1}.
15562 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15563 Maximum number of processes that can exist for this service. If set to
15564 0, @code{default-process-limit} is used instead.
15566 Defaults to @samp{0}.
15570 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15571 Number of processes to always keep waiting for more connections.
15572 Defaults to @samp{0}.
15575 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15576 If you set @samp{service-count 0}, you probably need to grow
15578 Defaults to @samp{256000000}.
15583 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15584 Dict configuration, as created by the @code{dict-configuration}
15587 Available @code{dict-configuration} fields are:
15589 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15590 A list of key-value pairs that this dict should hold.
15591 Defaults to @samp{()}.
15596 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15597 A list of passdb configurations, each one created by the
15598 @code{passdb-configuration} constructor.
15600 Available @code{passdb-configuration} fields are:
15602 @deftypevr {@code{passdb-configuration} parameter} string driver
15603 The driver that the passdb should use. Valid values include
15604 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15606 Defaults to @samp{"pam"}.
15609 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15610 Space separated list of arguments to the passdb driver.
15611 Defaults to @samp{""}.
15616 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15617 List of userdb configurations, each one created by the
15618 @code{userdb-configuration} constructor.
15620 Available @code{userdb-configuration} fields are:
15622 @deftypevr {@code{userdb-configuration} parameter} string driver
15623 The driver that the userdb should use. Valid values include
15624 @samp{passwd} and @samp{static}.
15625 Defaults to @samp{"passwd"}.
15628 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15629 Space separated list of arguments to the userdb driver.
15630 Defaults to @samp{""}.
15633 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15634 Override fields from passwd.
15635 Defaults to @samp{()}.
15640 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15641 Plug-in configuration, created by the @code{plugin-configuration}
15645 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15646 List of namespaces. Each item in the list is created by the
15647 @code{namespace-configuration} constructor.
15649 Available @code{namespace-configuration} fields are:
15651 @deftypevr {@code{namespace-configuration} parameter} string name
15652 Name for this namespace.
15655 @deftypevr {@code{namespace-configuration} parameter} string type
15656 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15657 Defaults to @samp{"private"}.
15660 @deftypevr {@code{namespace-configuration} parameter} string separator
15661 Hierarchy separator to use. You should use the same separator for
15662 all namespaces or some clients get confused. @samp{/} is usually a good
15663 one. The default however depends on the underlying mail storage
15665 Defaults to @samp{""}.
15668 @deftypevr {@code{namespace-configuration} parameter} string prefix
15669 Prefix required to access this namespace. This needs to be
15670 different for all namespaces. For example @samp{Public/}.
15671 Defaults to @samp{""}.
15674 @deftypevr {@code{namespace-configuration} parameter} string location
15675 Physical location of the mailbox. This is in the same format as
15676 mail_location, which is also the default for it.
15677 Defaults to @samp{""}.
15680 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15681 There can be only one INBOX, and this setting defines which
15683 Defaults to @samp{#f}.
15686 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15687 If namespace is hidden, it's not advertised to clients via NAMESPACE
15688 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15689 useful when converting from another server with different namespaces
15690 which you want to deprecate but still keep working. For example you can
15691 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15693 Defaults to @samp{#f}.
15696 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15697 Show the mailboxes under this namespace with the LIST command. This
15698 makes the namespace visible for clients that do not support the NAMESPACE
15699 extension. The special @code{children} value lists child mailboxes, but
15700 hides the namespace prefix.
15701 Defaults to @samp{#t}.
15704 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15705 Namespace handles its own subscriptions. If set to @code{#f}, the
15706 parent namespace handles them. The empty prefix should always have this
15708 Defaults to @samp{#t}.
15711 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15712 List of predefined mailboxes in this namespace.
15713 Defaults to @samp{()}.
15715 Available @code{mailbox-configuration} fields are:
15717 @deftypevr {@code{mailbox-configuration} parameter} string name
15718 Name for this mailbox.
15721 @deftypevr {@code{mailbox-configuration} parameter} string auto
15722 @samp{create} will automatically create this mailbox.
15723 @samp{subscribe} will both create and subscribe to the mailbox.
15724 Defaults to @samp{"no"}.
15727 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15728 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15729 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15730 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15731 Defaults to @samp{()}.
15738 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15739 Base directory where to store runtime data.
15740 Defaults to @samp{"/var/run/dovecot/"}.
15743 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15744 Greeting message for clients.
15745 Defaults to @samp{"Dovecot ready."}.
15748 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15749 List of trusted network ranges. Connections from these IPs are
15750 allowed to override their IP addresses and ports (for logging and for
15751 authentication checks). @samp{disable-plaintext-auth} is also ignored
15752 for these networks. Typically you would specify your IMAP proxy servers
15754 Defaults to @samp{()}.
15757 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15758 List of login access check sockets (e.g.@: tcpwrap).
15759 Defaults to @samp{()}.
15762 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15763 Show more verbose process titles (in ps). Currently shows user name
15764 and IP address. Useful for seeing who is actually using the IMAP
15765 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15767 Defaults to @samp{#f}.
15770 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15771 Should all processes be killed when Dovecot master process shuts down.
15772 Setting this to @code{#f} means that Dovecot can be upgraded without
15773 forcing existing client connections to close (although that could also
15774 be a problem if the upgrade is e.g.@: due to a security fix).
15775 Defaults to @samp{#t}.
15778 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15779 If non-zero, run mail commands via this many connections to doveadm
15780 server, instead of running them directly in the same process.
15781 Defaults to @samp{0}.
15784 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15785 UNIX socket or host:port used for connecting to doveadm server.
15786 Defaults to @samp{"doveadm-server"}.
15789 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15790 List of environment variables that are preserved on Dovecot startup
15791 and passed down to all of its child processes. You can also give
15792 key=value pairs to always set specific settings.
15795 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15796 Disable LOGIN command and all other plaintext authentications unless
15797 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15798 matches the local IP (i.e.@: you're connecting from the same computer),
15799 the connection is considered secure and plaintext authentication is
15800 allowed. See also ssl=required setting.
15801 Defaults to @samp{#t}.
15804 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15805 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15806 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15807 for caching to be used.
15808 Defaults to @samp{0}.
15811 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15812 Time to live for cached data. After TTL expires the cached record
15813 is no longer used, *except* if the main database lookup returns internal
15814 failure. We also try to handle password changes automatically: If
15815 user's previous authentication was successful, but this one wasn't, the
15816 cache isn't used. For now this works only with plaintext
15818 Defaults to @samp{"1 hour"}.
15821 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15822 TTL for negative hits (user not found, password mismatch).
15823 0 disables caching them completely.
15824 Defaults to @samp{"1 hour"}.
15827 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15828 List of realms for SASL authentication mechanisms that need them.
15829 You can leave it empty if you don't want to support multiple realms.
15830 Many clients simply use the first one listed here, so keep the default
15832 Defaults to @samp{()}.
15835 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15836 Default realm/domain to use if none was specified. This is used for
15837 both SASL realms and appending @@domain to username in plaintext
15839 Defaults to @samp{""}.
15842 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15843 List of allowed characters in username. If the user-given username
15844 contains a character not listed in here, the login automatically fails.
15845 This is just an extra check to make sure user can't exploit any
15846 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15847 you want to allow all characters, set this value to empty.
15848 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15851 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15852 Username character translations before it's looked up from
15853 databases. The value contains series of from -> to characters. For
15854 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15855 translated to @samp{@@}.
15856 Defaults to @samp{""}.
15859 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15860 Username formatting before it's looked up from databases. You can
15861 use the standard variables here, e.g.@: %Lu would lowercase the username,
15862 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15863 change the @samp{@@} into @samp{-AT-}. This translation is done after
15864 @samp{auth-username-translation} changes.
15865 Defaults to @samp{"%Lu"}.
15868 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15869 If you want to allow master users to log in by specifying the master
15870 username within the normal username string (i.e.@: not using SASL
15871 mechanism's support for it), you can specify the separator character
15872 here. The format is then <username><separator><master username>.
15873 UW-IMAP uses @samp{*} as the separator, so that could be a good
15875 Defaults to @samp{""}.
15878 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15879 Username to use for users logging in with ANONYMOUS SASL
15881 Defaults to @samp{"anonymous"}.
15884 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15885 Maximum number of dovecot-auth worker processes. They're used to
15886 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15887 They're automatically created and destroyed as needed.
15888 Defaults to @samp{30}.
15891 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15892 Host name to use in GSSAPI principal names. The default is to use
15893 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15894 allow all keytab entries.
15895 Defaults to @samp{""}.
15898 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
15899 Kerberos keytab to use for the GSSAPI mechanism. Will use the
15900 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
15901 need to change the auth service to run as root to be able to read this
15903 Defaults to @samp{""}.
15906 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
15907 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
15908 and @samp{ntlm-auth} helper.
15909 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
15910 Defaults to @samp{#f}.
15913 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
15914 Path for Samba's @samp{ntlm-auth} helper binary.
15915 Defaults to @samp{"/usr/bin/ntlm_auth"}.
15918 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
15919 Time to delay before replying to failed authentications.
15920 Defaults to @samp{"2 secs"}.
15923 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
15924 Require a valid SSL client certificate or the authentication
15926 Defaults to @samp{#f}.
15929 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
15930 Take the username from client's SSL certificate, using
15931 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
15933 Defaults to @samp{#f}.
15936 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
15937 List of wanted authentication mechanisms. Supported mechanisms are:
15938 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
15939 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
15940 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
15941 @samp{disable-plaintext-auth} setting.
15944 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
15945 List of IPs or hostnames to all director servers, including ourself.
15946 Ports can be specified as ip:port. The default port is the same as what
15947 director service's @samp{inet-listener} is using.
15948 Defaults to @samp{()}.
15951 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
15952 List of IPs or hostnames to all backend mail servers. Ranges are
15953 allowed too, like 10.0.0.10-10.0.0.30.
15954 Defaults to @samp{()}.
15957 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
15958 How long to redirect users to a specific server after it no longer
15959 has any connections.
15960 Defaults to @samp{"15 min"}.
15963 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
15964 How the username is translated before being hashed. Useful values
15965 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
15966 are shared within domain.
15967 Defaults to @samp{"%Lu"}.
15970 @deftypevr {@code{dovecot-configuration} parameter} string log-path
15971 Log file to use for error messages. @samp{syslog} logs to syslog,
15972 @samp{/dev/stderr} logs to stderr.
15973 Defaults to @samp{"syslog"}.
15976 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
15977 Log file to use for informational messages. Defaults to
15979 Defaults to @samp{""}.
15982 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
15983 Log file to use for debug messages. Defaults to
15984 @samp{info-log-path}.
15985 Defaults to @samp{""}.
15988 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
15989 Syslog facility to use if you're logging to syslog. Usually if you
15990 don't want to use @samp{mail}, you'll use local0..local7. Also other
15991 standard facilities are supported.
15992 Defaults to @samp{"mail"}.
15995 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
15996 Log unsuccessful authentication attempts and the reasons why they
15998 Defaults to @samp{#f}.
16001 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
16002 In case of password mismatches, log the attempted password. Valid
16003 values are no, plain and sha1. sha1 can be useful for detecting brute
16004 force password attempts vs. user simply trying the same password over
16005 and over again. You can also truncate the value to n chars by appending
16006 ":n" (e.g.@: sha1:6).
16007 Defaults to @samp{"no"}.
16010 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
16011 Even more verbose logging for debugging purposes. Shows for example
16013 Defaults to @samp{#f}.
16016 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
16017 In case of password mismatches, log the passwords and used scheme so
16018 the problem can be debugged. Enabling this also enables
16020 Defaults to @samp{#f}.
16023 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
16024 Enable mail process debugging. This can help you figure out why
16025 Dovecot isn't finding your mails.
16026 Defaults to @samp{#f}.
16029 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
16030 Show protocol level SSL errors.
16031 Defaults to @samp{#f}.
16034 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
16035 Prefix for each line written to log file. % codes are in
16036 strftime(3) format.
16037 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
16040 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
16041 List of elements we want to log. The elements which have a
16042 non-empty variable value are joined together to form a comma-separated
16046 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
16047 Login log format. %s contains @samp{login-log-format-elements}
16048 string, %$ contains the data we want to log.
16049 Defaults to @samp{"%$: %s"}.
16052 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
16053 Log prefix for mail processes. See doc/wiki/Variables.txt for list
16054 of possible variables you can use.
16055 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
16058 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
16059 Format to use for logging mail deliveries. You can use variables:
16062 Delivery status message (e.g.@: @samp{saved to INBOX})
16074 Defaults to @samp{"msgid=%m: %$"}.
16077 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
16078 Location for users' mailboxes. The default is empty, which means
16079 that Dovecot tries to find the mailboxes automatically. This won't work
16080 if the user doesn't yet have any mail, so you should explicitly tell
16081 Dovecot the full location.
16083 If you're using mbox, giving a path to the INBOX
16084 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
16085 where the other mailboxes are kept. This is called the "root mail
16086 directory", and it must be the first path given in the
16087 @samp{mail-location} setting.
16089 There are a few special variables you can use, eg.:
16095 user part in user@@domain, same as %u if there's no domain
16097 domain part in user@@domain, empty if there's no domain
16102 See doc/wiki/Variables.txt for full list. Some examples:
16104 @item maildir:~/Maildir
16105 @item mbox:~/mail:INBOX=/var/mail/%u
16106 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
16108 Defaults to @samp{""}.
16111 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
16112 System user and group used to access mails. If you use multiple,
16113 userdb can override these by returning uid or gid fields. You can use
16114 either numbers or names. <doc/wiki/UserIds.txt>.
16115 Defaults to @samp{""}.
16118 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16120 Defaults to @samp{""}.
16123 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16124 Group to enable temporarily for privileged operations. Currently
16125 this is used only with INBOX when either its initial creation or
16126 dotlocking fails. Typically this is set to "mail" to give access to
16128 Defaults to @samp{""}.
16131 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16132 Grant access to these supplementary groups for mail processes.
16133 Typically these are used to set up access to shared mailboxes. Note
16134 that it may be dangerous to set these if users can create
16135 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16136 could allow a user to delete others' mailboxes, or ln -s
16137 /secret/shared/box ~/mail/mybox would allow reading it).
16138 Defaults to @samp{""}.
16141 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16142 Allow full file system access to clients. There's no access checks
16143 other than what the operating system does for the active UID/GID. It
16144 works with both maildir and mboxes, allowing you to prefix mailboxes
16145 names with e.g.@: /path/ or ~user/.
16146 Defaults to @samp{#f}.
16149 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16150 Don't use mmap() at all. This is required if you store indexes to
16151 shared file systems (NFS or clustered file system).
16152 Defaults to @samp{#f}.
16155 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16156 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16157 supports @samp{O_EXCL} since version 3, so this should be safe to use
16158 nowadays by default.
16159 Defaults to @samp{#t}.
16162 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16163 When to use fsync() or fdatasync() calls:
16166 Whenever necessary to avoid losing important data
16168 Useful with e.g.@: NFS when write()s are delayed
16170 Never use it (best performance, but crashes can lose data).
16172 Defaults to @samp{"optimized"}.
16175 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16176 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16177 NFS caches whenever needed. If you're using only a single mail server
16179 Defaults to @samp{#f}.
16182 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16183 Mail index files also exist in NFS. Setting this to yes requires
16184 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16185 Defaults to @samp{#f}.
16188 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16189 Locking method for index files. Alternatives are fcntl, flock and
16190 dotlock. Dotlocking uses some tricks which may create more disk I/O
16191 than other locking methods. NFS users: flock doesn't work, remember to
16192 change @samp{mmap-disable}.
16193 Defaults to @samp{"fcntl"}.
16196 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16197 Directory in which LDA/LMTP temporarily stores incoming mails >128
16199 Defaults to @samp{"/tmp"}.
16202 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16203 Valid UID range for users. This is mostly to make sure that users can't
16204 log in as daemons or other system users. Note that denying root logins is
16205 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16207 Defaults to @samp{500}.
16210 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16212 Defaults to @samp{0}.
16215 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16216 Valid GID range for users. Users having non-valid GID as primary group ID
16217 aren't allowed to log in. If user belongs to supplementary groups with
16218 non-valid GIDs, those groups are not set.
16219 Defaults to @samp{1}.
16222 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16224 Defaults to @samp{0}.
16227 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16228 Maximum allowed length for mail keyword name. It's only forced when
16229 trying to create new keywords.
16230 Defaults to @samp{50}.
16233 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16234 List of directories under which chrooting is allowed for mail
16235 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16236 too). This setting doesn't affect @samp{login-chroot}
16237 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16238 "/./" in home dirs are ignored. WARNING: Never add directories here
16239 which local users can modify, that may lead to root exploit. Usually
16240 this should be done only if you don't allow shell access for users.
16241 <doc/wiki/Chrooting.txt>.
16242 Defaults to @samp{()}.
16245 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16246 Default chroot directory for mail processes. This can be overridden
16247 for specific users in user database by giving /./ in user's home
16248 directory (e.g.@: /home/./user chroots into /home). Note that usually
16249 there is no real need to do chrooting, Dovecot doesn't allow users to
16250 access files outside their mail directory anyway. If your home
16251 directories are prefixed with the chroot directory, append "/."@: to
16252 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16253 Defaults to @samp{""}.
16256 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16257 UNIX socket path to master authentication server to find users.
16258 This is used by imap (for shared users) and lda.
16259 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16262 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16263 Directory where to look up mail plugins.
16264 Defaults to @samp{"/usr/lib/dovecot"}.
16267 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16268 List of plugins to load for all services. Plugins specific to IMAP,
16269 LDA, etc.@: are added to this list in their own .conf files.
16270 Defaults to @samp{()}.
16273 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16274 The minimum number of mails in a mailbox before updates are done to
16275 cache file. This allows optimizing Dovecot's behavior to do less disk
16276 writes at the cost of more disk reads.
16277 Defaults to @samp{0}.
16280 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16281 When IDLE command is running, mailbox is checked once in a while to
16282 see if there are any new mails or other changes. This setting defines
16283 the minimum time to wait between those checks. Dovecot can also use
16284 dnotify, inotify and kqueue to find out immediately when changes
16286 Defaults to @samp{"30 secs"}.
16289 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16290 Save mails with CR+LF instead of plain LF. This makes sending those
16291 mails take less CPU, especially with sendfile() syscall with Linux and
16292 FreeBSD. But it also creates a bit more disk I/O which may just make it
16293 slower. Also note that if other software reads the mboxes/maildirs,
16294 they may handle the extra CRs wrong and cause problems.
16295 Defaults to @samp{#f}.
16298 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16299 By default LIST command returns all entries in maildir beginning
16300 with a dot. Enabling this option makes Dovecot return only entries
16301 which are directories. This is done by stat()ing each entry, so it
16302 causes more disk I/O.
16303 (For systems setting struct @samp{dirent->d_type} this check is free
16304 and it's done always regardless of this setting).
16305 Defaults to @samp{#f}.
16308 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16309 When copying a message, do it with hard links whenever possible.
16310 This makes the performance much better, and it's unlikely to have any
16312 Defaults to @samp{#t}.
16315 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16316 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16317 directory only when its mtime changes unexpectedly or when we can't find
16318 the mail otherwise.
16319 Defaults to @samp{#f}.
16322 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16323 Which locking methods to use for locking mbox. There are four
16328 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16329 solution. If you want to use /var/mail/ like directory, the users will
16330 need write access to that directory.
16332 Same as dotlock, but if it fails because of permissions or because there
16333 isn't enough disk space, just skip it.
16335 Use this if possible. Works with NFS too if lockd is used.
16337 May not exist in all systems. Doesn't work with NFS.
16339 May not exist in all systems. Doesn't work with NFS.
16342 You can use multiple locking methods; if you do the order they're declared
16343 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16344 locking methods as well. Some operating systems don't allow using some of
16345 them simultaneously.
16348 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16352 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16353 Maximum time to wait for lock (all of them) before aborting.
16354 Defaults to @samp{"5 mins"}.
16357 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16358 If dotlock exists but the mailbox isn't modified in any way,
16359 override the lock file after this much time.
16360 Defaults to @samp{"2 mins"}.
16363 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16364 When mbox changes unexpectedly we have to fully read it to find out
16365 what changed. If the mbox is large this can take a long time. Since
16366 the change is usually just a newly appended mail, it'd be faster to
16367 simply read the new mails. If this setting is enabled, Dovecot does
16368 this but still safely fallbacks to re-reading the whole mbox file
16369 whenever something in mbox isn't how it's expected to be. The only real
16370 downside to this setting is that if some other MUA changes message
16371 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16372 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16373 Defaults to @samp{#t}.
16376 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16377 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16378 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16379 @samp{mbox-dirty-syncs} is ignored.
16380 Defaults to @samp{#f}.
16383 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16384 Delay writing mbox headers until doing a full write sync (EXPUNGE
16385 and CHECK commands and when closing the mailbox). This is especially
16386 useful for POP3 where clients often delete all mails. The downside is
16387 that our changes aren't immediately visible to other MUAs.
16388 Defaults to @samp{#t}.
16391 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16392 If mbox size is smaller than this (e.g.@: 100k), don't write index
16393 files. If an index file already exists it's still read, just not
16395 Defaults to @samp{0}.
16398 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
16399 Maximum dbox file size until it's rotated.
16400 Defaults to @samp{10000000}.
16403 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
16404 Maximum dbox file age until it's rotated. Typically in days. Day
16405 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
16407 Defaults to @samp{"1d"}.
16410 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
16411 When creating new mdbox files, immediately preallocate their size to
16412 @samp{mdbox-rotate-size}. This setting currently works only in Linux
16413 with some file systems (ext4, xfs).
16414 Defaults to @samp{#f}.
16417 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
16418 sdbox and mdbox support saving mail attachments to external files,
16419 which also allows single instance storage for them. Other backends
16420 don't support this for now.
16422 WARNING: This feature hasn't been tested much yet. Use at your own risk.
16424 Directory root where to store mail attachments. Disabled, if empty.
16425 Defaults to @samp{""}.
16428 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
16429 Attachments smaller than this aren't saved externally. It's also
16430 possible to write a plugin to disable saving specific attachments
16432 Defaults to @samp{128000}.
16435 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
16436 File system backend to use for saving attachments:
16439 No SiS done by Dovecot (but this might help FS's own deduplication)
16441 SiS with immediate byte-by-byte comparison during saving
16442 @item sis-queue posix
16443 SiS with delayed comparison and deduplication.
16445 Defaults to @samp{"sis posix"}.
16448 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
16449 Hash format to use in attachment filenames. You can add any text and
16450 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16451 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16452 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16453 Defaults to @samp{"%@{sha1@}"}.
16456 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16458 Defaults to @samp{100}.
16461 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16463 Defaults to @samp{1000}.
16466 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16467 Default VSZ (virtual memory size) limit for service processes.
16468 This is mainly intended to catch and kill processes that leak memory
16469 before they eat up everything.
16470 Defaults to @samp{256000000}.
16473 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16474 Login user is internally used by login processes. This is the most
16475 untrusted user in Dovecot system. It shouldn't have access to anything
16477 Defaults to @samp{"dovenull"}.
16480 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16481 Internal user is used by unprivileged processes. It should be
16482 separate from login user, so that login processes can't disturb other
16484 Defaults to @samp{"dovecot"}.
16487 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16488 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16489 Defaults to @samp{"required"}.
16492 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16493 PEM encoded X.509 SSL/TLS certificate (public key).
16494 Defaults to @samp{"</etc/dovecot/default.pem"}.
16497 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16498 PEM encoded SSL/TLS private key. The key is opened before
16499 dropping root privileges, so keep the key file unreadable by anyone but
16501 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16504 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16505 If key file is password protected, give the password here.
16506 Alternatively give it when starting dovecot with -p parameter. Since
16507 this file is often world-readable, you may want to place this setting
16508 instead to a different.
16509 Defaults to @samp{""}.
16512 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16513 PEM encoded trusted certificate authority. Set this only if you
16514 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16515 contain the CA certificate(s) followed by the matching
16516 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16517 Defaults to @samp{""}.
16520 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16521 Require that CRL check succeeds for client certificates.
16522 Defaults to @samp{#t}.
16525 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16526 Request client to send a certificate. If you also want to require
16527 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16528 Defaults to @samp{#f}.
16531 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16532 Which field from certificate to use for username. commonName and
16533 x500UniqueIdentifier are the usual choices. You'll also need to set
16534 @samp{auth-ssl-username-from-cert? #t}.
16535 Defaults to @samp{"commonName"}.
16538 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16539 Minimum SSL protocol version to accept.
16540 Defaults to @samp{"TLSv1"}.
16543 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16544 SSL ciphers to use.
16545 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16548 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16549 SSL crypto device to use, for valid values run "openssl engine".
16550 Defaults to @samp{""}.
16553 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16554 Address to use when sending rejection mails.
16555 %d expands to recipient domain.
16556 Defaults to @samp{"postmaster@@%d"}.
16559 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16560 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16561 and in LMTP replies. Default is the system's real hostname@@domain.
16562 Defaults to @samp{""}.
16565 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16566 If user is over quota, return with temporary failure instead of
16568 Defaults to @samp{#f}.
16571 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16572 Binary to use for sending mails.
16573 Defaults to @samp{"/usr/sbin/sendmail"}.
16576 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16577 If non-empty, send mails via this SMTP host[:port] instead of
16579 Defaults to @samp{""}.
16582 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16583 Subject: header to use for rejection mails. You can use the same
16584 variables as for @samp{rejection-reason} below.
16585 Defaults to @samp{"Rejected: %s"}.
16588 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16589 Human readable error message for rejection mails. You can use
16602 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16605 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16606 Delimiter character between local-part and detail in email
16608 Defaults to @samp{"+"}.
16611 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16612 Header where the original recipient address (SMTP's RCPT TO:
16613 address) is taken from if not available elsewhere. With dovecot-lda -a
16614 parameter overrides this. A commonly used header for this is
16616 Defaults to @samp{""}.
16619 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16620 Should saving a mail to a nonexistent mailbox automatically create
16622 Defaults to @samp{#f}.
16625 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16626 Should automatically created mailboxes be also automatically
16628 Defaults to @samp{#f}.
16631 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16632 Maximum IMAP command line length. Some clients generate very long
16633 command lines with huge mailboxes, so you may need to raise this if you
16634 get "Too long argument" or "IMAP command line too large" errors
16636 Defaults to @samp{64000}.
16639 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16640 IMAP logout format string:
16643 total number of bytes read from client
16645 total number of bytes sent to client.
16647 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16648 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@}"}.
16651 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16652 Override the IMAP CAPABILITY response. If the value begins with '+',
16653 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16654 Defaults to @samp{""}.
16657 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16658 How long to wait between "OK Still here" notifications when client
16660 Defaults to @samp{"2 mins"}.
16663 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16664 ID field names and values to send to clients. Using * as the value
16665 makes Dovecot use the default value. The following fields have default
16666 values currently: name, version, os, os-version, support-url,
16668 Defaults to @samp{""}.
16671 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16672 ID fields sent by client to log. * means everything.
16673 Defaults to @samp{""}.
16676 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16677 Workarounds for various client bugs:
16680 @item delay-newmail
16681 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16682 CHECK commands. Some clients ignore them otherwise, for example OSX
16683 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16684 may show user "Message no longer in server" errors. Note that OE6
16685 still breaks even with this workaround if synchronization is set to
16688 @item tb-extra-mailbox-sep
16689 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16690 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16691 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16693 @item tb-lsub-flags
16694 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16695 This makes Thunderbird realize they aren't selectable and show them
16696 greyed out, instead of only later giving "not selectable" popup error.
16698 Defaults to @samp{()}.
16701 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16702 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16703 Defaults to @samp{""}.
16707 Whew! Lots of configuration options. The nice thing about it though is
16708 that Guix has a complete interface to Dovecot's configuration
16709 language. This allows not only a nice way to declare configurations,
16710 but also offers reflective capabilities as well: users can write code to
16711 inspect and transform configurations from within Scheme.
16713 However, it could be that you just want to get a @code{dovecot.conf} up
16714 and running. In that case, you can pass an
16715 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16716 @code{dovecot-service}. As its name indicates, an opaque configuration
16717 does not have easy reflective capabilities.
16719 Available @code{opaque-dovecot-configuration} fields are:
16721 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16722 The dovecot package.
16725 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16726 The contents of the @code{dovecot.conf}, as a string.
16729 For example, if your @code{dovecot.conf} is just the empty string, you
16730 could instantiate a dovecot service like this:
16733 (dovecot-service #:config
16734 (opaque-dovecot-configuration
16738 @subsubheading OpenSMTPD Service
16740 @deffn {Scheme Variable} opensmtpd-service-type
16741 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16742 service, whose value should be an @code{opensmtpd-configuration} object
16743 as in this example:
16746 (service opensmtpd-service-type
16747 (opensmtpd-configuration
16748 (config-file (local-file "./my-smtpd.conf"))))
16752 @deftp {Data Type} opensmtpd-configuration
16753 Data type representing the configuration of opensmtpd.
16756 @item @code{package} (default: @var{opensmtpd})
16757 Package object of the OpenSMTPD SMTP server.
16759 @item @code{config-file} (default: @code{%default-opensmtpd-file})
16760 File-like object of the OpenSMTPD configuration file to use. By default
16761 it listens on the loopback network interface, and allows for mail from
16762 users and daemons on the local machine, as well as permitting email to
16763 remote servers. Run @command{man smtpd.conf} for more information.
16768 @subsubheading Exim Service
16770 @cindex mail transfer agent (MTA)
16771 @cindex MTA (mail transfer agent)
16774 @deffn {Scheme Variable} exim-service-type
16775 This is the type of the @uref{https://exim.org, Exim} mail transfer
16776 agent (MTA), whose value should be an @code{exim-configuration} object
16777 as in this example:
16780 (service exim-service-type
16781 (exim-configuration
16782 (config-file (local-file "./my-exim.conf"))))
16786 In order to use an @code{exim-service-type} service you must also have a
16787 @code{mail-aliases-service-type} service present in your
16788 @code{operating-system} (even if it has no aliases).
16790 @deftp {Data Type} exim-configuration
16791 Data type representing the configuration of exim.
16794 @item @code{package} (default: @var{exim})
16795 Package object of the Exim server.
16797 @item @code{config-file} (default: @code{#f})
16798 File-like object of the Exim configuration file to use. If its value is
16799 @code{#f} then use the default configuration file from the package
16800 provided in @code{package}. The resulting configuration file is loaded
16801 after setting the @code{exim_user} and @code{exim_group} configuration
16807 @subsubheading Getmail service
16812 @deffn {Scheme Variable} getmail-service-type
16813 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
16814 mail retriever, whose value should be an @code{getmail-configuration}.
16817 Available @code{getmail-configuration} fields are:
16819 @deftypevr {@code{getmail-configuration} parameter} symbol name
16820 A symbol to identify the getmail service.
16822 Defaults to @samp{"unset"}.
16826 @deftypevr {@code{getmail-configuration} parameter} package package
16827 The getmail package to use.
16831 @deftypevr {@code{getmail-configuration} parameter} string user
16832 The user to run getmail as.
16834 Defaults to @samp{"getmail"}.
16838 @deftypevr {@code{getmail-configuration} parameter} string group
16839 The group to run getmail as.
16841 Defaults to @samp{"getmail"}.
16845 @deftypevr {@code{getmail-configuration} parameter} string directory
16846 The getmail directory to use.
16848 Defaults to @samp{"/var/lib/getmail/default"}.
16852 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
16853 The getmail configuration file to use.
16855 Available @code{getmail-configuration-file} fields are:
16857 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
16858 What mail account to retrieve mail from, and how to access that account.
16860 Available @code{getmail-retriever-configuration} fields are:
16862 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
16863 The type of mail retriever to use. Valid values include @samp{passwd}
16866 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
16870 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
16871 Space separated list of arguments to the userdb driver.
16873 Defaults to @samp{unset}.
16877 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
16878 Space separated list of arguments to the userdb driver.
16880 Defaults to @samp{unset}.
16884 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
16885 Space separated list of arguments to the userdb driver.
16887 Defaults to @samp{#f}.
16891 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
16892 Override fields from passwd.
16894 Defaults to @samp{""}.
16898 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
16899 Override fields from passwd.
16901 Defaults to @samp{()}.
16905 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
16906 PEM-formatted key file to use for the TLS negotiation
16908 Defaults to @samp{""}.
16912 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
16913 PEM-formatted certificate file to use for the TLS negotiation
16915 Defaults to @samp{""}.
16919 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
16920 CA certificates to use
16922 Defaults to @samp{""}.
16926 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
16927 Extra retriever parameters
16929 Defaults to @samp{()}.
16935 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
16936 What to do with retrieved messages.
16938 Available @code{getmail-destination-configuration} fields are:
16940 @deftypevr {@code{getmail-destination-configuration} parameter} string type
16941 The type of mail destination. Valid values include @samp{Maildir},
16942 @samp{Mboxrd} and @samp{MDA_external}.
16944 Defaults to @samp{unset}.
16948 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
16949 The path option for the mail destination. The behaviour depends on the
16952 Defaults to @samp{""}.
16956 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
16957 Extra destination parameters
16959 Defaults to @samp{()}.
16965 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
16968 Available @code{getmail-options-configuration} fields are:
16970 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
16971 If set to @samp{0}, getmail will only print warnings and errors. A
16972 value of @samp{1} means that messages will be printed about retrieving
16973 and deleting messages. If set to @samp{2}, getmail will print messages
16974 about each of it's actions.
16976 Defaults to @samp{1}.
16980 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
16981 If true, getmail will retrieve all available messages. Otherwise it
16982 will only retrieve messages it hasn't seen previously.
16984 Defaults to @samp{#t}.
16988 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
16989 If set to true, messages will be deleted from the server after
16990 retrieving and successfully delivering them. Otherwise, messages will
16991 be left on the server.
16993 Defaults to @samp{#f}.
16997 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
16998 Getmail will delete messages this number of days after seeing them, if
16999 they have not been delivered. This means messages will be left on the
17000 server this number of days after delivering them. A value of @samp{0}
17001 disabled this feature.
17003 Defaults to @samp{0}.
17007 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
17008 Delete messages larger than this of bytes after retrieving them, even if
17009 the delete and delete-after options are disabled. A value of @samp{0}
17010 disables this feature.
17012 Defaults to @samp{0}.
17016 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
17017 Retrieve messages totalling up to this number of bytes before closing
17018 the session with the server. A value of @samp{0} disables this feature.
17020 Defaults to @samp{0}.
17024 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
17025 Don't retrieve messages larger than this number of bytes. A value of
17026 @samp{0} disables this feature.
17028 Defaults to @samp{0}.
17032 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
17033 If true, getmail will add a Delivered-To header to messages.
17035 Defaults to @samp{#t}.
17039 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
17040 If set, getmail adds a Received header to the messages.
17042 Defaults to @samp{#t}.
17046 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
17047 Getmail will record a log of its actions to the named file. A value of
17048 @samp{""} disables this feature.
17050 Defaults to @samp{""}.
17054 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
17055 If true, getmail will record a log of its actions using the system
17058 Defaults to @samp{#t}.
17062 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
17063 If true, getmail will log information about messages not retrieved and
17064 the reason for not retrieving them, as well as starting and ending
17067 Defaults to @samp{#t}.
17071 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
17072 Extra options to include.
17074 Defaults to @samp{()}.
17082 @deftypevr {@code{getmail-configuration} parameter} list idle
17083 A list of mailboxes that getmail should wait on the server for new mail
17084 notifications. This depends on the server supporting the IDLE
17087 Defaults to @samp{()}.
17091 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
17092 Environment variables to set for getmail.
17094 Defaults to @samp{()}.
17098 @subsubheading Mail Aliases Service
17100 @cindex email aliases
17101 @cindex aliases, for email addresses
17103 @deffn {Scheme Variable} mail-aliases-service-type
17104 This is the type of the service which provides @code{/etc/aliases},
17105 specifying how to deliver mail to users on this system.
17108 (service mail-aliases-service-type
17109 '(("postmaster" "bob")
17110 ("bob" "bob@@example.com" "bob@@example2.com")))
17114 The configuration for a @code{mail-aliases-service-type} service is an
17115 association list denoting how to deliver mail that comes to this
17116 system. Each entry is of the form @code{(alias addresses ...)}, with
17117 @code{alias} specifying the local alias and @code{addresses} specifying
17118 where to deliver this user's mail.
17120 The aliases aren't required to exist as users on the local system. In
17121 the above example, there doesn't need to be a @code{postmaster} entry in
17122 the @code{operating-system}'s @code{user-accounts} in order to deliver
17123 the @code{postmaster} mail to @code{bob} (which subsequently would
17124 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
17126 @subsubheading GNU Mailutils IMAP4 Daemon
17127 @cindex GNU Mailutils IMAP4 Daemon
17129 @deffn {Scheme Variable} imap4d-service-type
17130 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
17131 mailutils, GNU Mailutils Manual}), whose value should be an
17132 @code{imap4d-configuration} object as in this example:
17135 (service imap4d-service-type
17136 (imap4d-configuration
17137 (config-file (local-file "imap4d.conf"))))
17141 @deftp {Data Type} imap4d-configuration
17142 Data type representing the configuration of @command{imap4d}.
17145 @item @code{package} (default: @code{mailutils})
17146 The package that provides @command{imap4d}.
17148 @item @code{config-file} (default: @code{%default-imap4d-config-file})
17149 File-like object of the configuration file to use, by default it will listen
17150 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
17151 Mailutils Manual}, for details.
17156 @node Messaging Services
17157 @subsection Messaging Services
17162 The @code{(gnu services messaging)} module provides Guix service
17163 definitions for messaging services: currently only Prosody is supported.
17165 @subsubheading Prosody Service
17167 @deffn {Scheme Variable} prosody-service-type
17168 This is the type for the @uref{https://prosody.im, Prosody XMPP
17169 communication server}. Its value must be a @code{prosody-configuration}
17170 record as in this example:
17173 (service prosody-service-type
17174 (prosody-configuration
17175 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
17178 (int-component-configuration
17179 (hostname "conference.example.net")
17181 (mod-muc (mod-muc-configuration)))))
17184 (virtualhost-configuration
17185 (domain "example.net"))))))
17188 See below for details about @code{prosody-configuration}.
17192 By default, Prosody does not need much configuration. Only one
17193 @code{virtualhosts} field is needed: it specifies the domain you wish
17196 You can perform various sanity checks on the generated configuration
17197 with the @code{prosodyctl check} command.
17199 Prosodyctl will also help you to import certificates from the
17200 @code{letsencrypt} directory so that the @code{prosody} user can access
17201 them. See @url{https://prosody.im/doc/letsencrypt}.
17204 prosodyctl --root cert import /etc/letsencrypt/live
17207 The available configuration parameters follow. Each parameter
17208 definition is preceded by its type; for example, @samp{string-list foo}
17209 indicates that the @code{foo} parameter should be specified as a list of
17210 strings. Types starting with @code{maybe-} denote parameters that won't
17211 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
17213 There is also a way to specify the configuration as a string, if you
17214 have an old @code{prosody.cfg.lua} file that you want to port over from
17215 some other system; see the end for more details.
17217 The @code{file-object} type designates either a file-like object
17218 (@pxref{G-Expressions, file-like objects}) or a file name.
17220 @c The following documentation was initially generated by
17221 @c (generate-documentation) in (gnu services messaging). Manually maintained
17222 @c documentation is better, so we shouldn't hesitate to edit below as
17223 @c needed. However if the change you want to make to this documentation
17224 @c can be done in an automated way, it's probably easier to change
17225 @c (generate-documentation) than to make it below and have to deal with
17226 @c the churn as Prosody updates.
17228 Available @code{prosody-configuration} fields are:
17230 @deftypevr {@code{prosody-configuration} parameter} package prosody
17231 The Prosody package.
17234 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
17235 Location of the Prosody data storage directory. See
17236 @url{https://prosody.im/doc/configure}.
17237 Defaults to @samp{"/var/lib/prosody"}.
17240 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
17241 Additional plugin directories. They are searched in all the specified
17242 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
17243 Defaults to @samp{()}.
17246 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
17247 Every virtual host and component needs a certificate so that clients and
17248 servers can securely verify its identity. Prosody will automatically load
17249 certificates/keys from the directory specified here.
17250 Defaults to @samp{"/etc/prosody/certs"}.
17253 @deftypevr {@code{prosody-configuration} parameter} string-list admins
17254 This is a list of accounts that are admins for the server. Note that you
17255 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
17256 @url{https://prosody.im/doc/creating_accounts}.
17257 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
17258 Defaults to @samp{()}.
17261 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
17262 Enable use of libevent for better performance under high load. See
17263 @url{https://prosody.im/doc/libevent}.
17264 Defaults to @samp{#f}.
17267 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
17268 This is the list of modules Prosody will load on startup. It looks for
17269 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
17270 Documentation on modules can be found at:
17271 @url{https://prosody.im/doc/modules}.
17272 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
17275 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
17276 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
17277 should you want to disable them then add them to this list.
17278 Defaults to @samp{()}.
17281 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
17282 Path to a text file where the shared groups are defined. If this path is
17283 empty then @samp{mod_groups} does nothing. See
17284 @url{https://prosody.im/doc/modules/mod_groups}.
17285 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
17288 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
17289 Disable account creation by default, for security. See
17290 @url{https://prosody.im/doc/creating_accounts}.
17291 Defaults to @samp{#f}.
17294 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
17295 These are the SSL/TLS-related settings. Most of them are disabled so to
17296 use Prosody's defaults. If you do not completely understand these options, do
17297 not add them to your config, it is easy to lower the security of your server
17298 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
17300 Available @code{ssl-configuration} fields are:
17302 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
17303 This determines what handshake to use.
17306 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
17307 Path to your private key file.
17310 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
17311 Path to your certificate file.
17314 @deftypevr {@code{ssl-configuration} parameter} file-object capath
17315 Path to directory containing root certificates that you wish Prosody to
17316 trust when verifying the certificates of remote servers.
17317 Defaults to @samp{"/etc/ssl/certs"}.
17320 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
17321 Path to a file containing root certificates that you wish Prosody to trust.
17322 Similar to @code{capath} but with all certificates concatenated together.
17325 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
17326 A list of verification options (these mostly map to OpenSSL's
17327 @code{set_verify()} flags).
17330 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
17331 A list of general options relating to SSL/TLS. These map to OpenSSL's
17332 @code{set_options()}. For a full list of options available in LuaSec, see the
17336 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
17337 How long a chain of certificate authorities to check when looking for a
17338 trusted root certificate.
17341 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
17342 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
17343 clients, and in what order.
17346 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
17347 A path to a file containing parameters for Diffie-Hellman key exchange. You
17348 can create such a file with:
17349 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
17352 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
17353 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
17354 @samp{"secp384r1"}.
17357 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
17358 A list of "extra" verification options.
17361 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
17362 Password for encrypted private keys.
17367 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
17368 Whether to force all client-to-server connections to be encrypted or not.
17369 See @url{https://prosody.im/doc/modules/mod_tls}.
17370 Defaults to @samp{#f}.
17373 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
17374 Set of mechanisms that will never be offered. See
17375 @url{https://prosody.im/doc/modules/mod_saslauth}.
17376 Defaults to @samp{("DIGEST-MD5")}.
17379 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
17380 Whether to force all server-to-server connections to be encrypted or not.
17381 See @url{https://prosody.im/doc/modules/mod_tls}.
17382 Defaults to @samp{#f}.
17385 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
17386 Whether to require encryption and certificate authentication. This
17387 provides ideal security, but requires servers you communicate with to support
17388 encryption AND present valid, trusted certificates. See
17389 @url{https://prosody.im/doc/s2s#security}.
17390 Defaults to @samp{#f}.
17393 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
17394 Many servers don't support encryption or have invalid or self-signed
17395 certificates. You can list domains here that will not be required to
17396 authenticate using certificates. They will be authenticated using DNS. See
17397 @url{https://prosody.im/doc/s2s#security}.
17398 Defaults to @samp{()}.
17401 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
17402 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
17403 valid certificates for some domains by specifying a list here. See
17404 @url{https://prosody.im/doc/s2s#security}.
17405 Defaults to @samp{()}.
17408 @deftypevr {@code{prosody-configuration} parameter} string authentication
17409 Select the authentication backend to use. The default provider stores
17410 passwords in plaintext and uses Prosody's configured data storage to store the
17411 authentication data. If you do not trust your server please see
17412 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
17413 about using the hashed backend. See also
17414 @url{https://prosody.im/doc/authentication}
17415 Defaults to @samp{"internal_plain"}.
17418 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
17419 Set logging options. Advanced logging configuration is not yet supported
17420 by the Prosody service. See @url{https://prosody.im/doc/logging}.
17421 Defaults to @samp{"*syslog"}.
17424 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
17425 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
17426 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
17429 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
17430 Maximum allowed size of the HTTP body (in bytes).
17433 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
17434 Some modules expose their own URL in various ways. This URL is built
17435 from the protocol, host and port used. If Prosody sits behind a proxy, the
17436 public URL will be @code{http-external-url} instead. See
17437 @url{https://prosody.im/doc/http#external_url}.
17440 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
17441 A host in Prosody is a domain on which user accounts can be created. For
17442 example if you want your users to have addresses like
17443 @samp{"john.smith@@example.com"} then you need to add a host
17444 @samp{"example.com"}. All options in this list will apply only to this host.
17446 Note: the name "virtual" host is used in configuration to avoid confusion with
17447 the actual physical host that Prosody is installed on. A single Prosody
17448 instance can serve many domains, each one defined as a VirtualHost entry in
17449 Prosody's configuration. Conversely a server that hosts a single domain would
17450 have just one VirtualHost entry.
17452 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
17454 Available @code{virtualhost-configuration} fields are:
17456 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:
17457 @deftypevr {@code{virtualhost-configuration} parameter} string domain
17458 Domain you wish Prosody to serve.
17463 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
17464 Components are extra services on a server which are available to clients,
17465 usually on a subdomain of the main server (such as
17466 @samp{"mycomponent.example.com"}). Example components might be chatroom
17467 servers, user directories, or gateways to other protocols.
17469 Internal components are implemented with Prosody-specific plugins. To add an
17470 internal component, you simply fill the hostname field, and the plugin you wish
17471 to use for the component.
17473 See @url{https://prosody.im/doc/components}.
17474 Defaults to @samp{()}.
17476 Available @code{int-component-configuration} fields are:
17478 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:
17479 @deftypevr {@code{int-component-configuration} parameter} string hostname
17480 Hostname of the component.
17483 @deftypevr {@code{int-component-configuration} parameter} string plugin
17484 Plugin you wish to use for the component.
17487 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
17488 Multi-user chat (MUC) is Prosody's module for allowing you to create
17489 hosted chatrooms/conferences for XMPP users.
17491 General information on setting up and using multi-user chatrooms can be found
17492 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
17493 which you should read if you are new to XMPP chatrooms.
17495 See also @url{https://prosody.im/doc/modules/mod_muc}.
17497 Available @code{mod-muc-configuration} fields are:
17499 @deftypevr {@code{mod-muc-configuration} parameter} string name
17500 The name to return in service discovery responses.
17501 Defaults to @samp{"Prosody Chatrooms"}.
17504 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
17505 If @samp{#t}, this will only allow admins to create new chatrooms.
17506 Otherwise anyone can create a room. The value @samp{"local"} restricts room
17507 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
17508 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
17509 restricts to service administrators only.
17510 Defaults to @samp{#f}.
17513 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
17514 Maximum number of history messages that will be sent to the member that has
17515 just joined the room.
17516 Defaults to @samp{20}.
17523 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
17524 External components use XEP-0114, which most standalone components
17525 support. To add an external component, you simply fill the hostname field. See
17526 @url{https://prosody.im/doc/components}.
17527 Defaults to @samp{()}.
17529 Available @code{ext-component-configuration} fields are:
17531 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:
17532 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
17533 Password which the component will use to log in.
17536 @deftypevr {@code{ext-component-configuration} parameter} string hostname
17537 Hostname of the component.
17542 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
17543 Port(s) Prosody listens on for component connections.
17544 Defaults to @samp{(5347)}.
17547 @deftypevr {@code{prosody-configuration} parameter} string component-interface
17548 Interface Prosody listens on for component connections.
17549 Defaults to @samp{"127.0.0.1"}.
17552 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
17553 Raw content that will be added to the configuration file.
17556 It could be that you just want to get a @code{prosody.cfg.lua}
17557 up and running. In that case, you can pass an
17558 @code{opaque-prosody-configuration} record as the value of
17559 @code{prosody-service-type}. As its name indicates, an opaque configuration
17560 does not have easy reflective capabilities.
17561 Available @code{opaque-prosody-configuration} fields are:
17563 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
17564 The prosody package.
17567 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
17568 The contents of the @code{prosody.cfg.lua} to use.
17571 For example, if your @code{prosody.cfg.lua} is just the empty
17572 string, you could instantiate a prosody service like this:
17575 (service prosody-service-type
17576 (opaque-prosody-configuration
17577 (prosody.cfg.lua "")))
17580 @c end of Prosody auto-generated documentation
17582 @subsubheading BitlBee Service
17584 @cindex IRC (Internet Relay Chat)
17585 @cindex IRC gateway
17586 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
17587 interface to a variety of messaging protocols such as XMPP.
17589 @defvr {Scheme Variable} bitlbee-service-type
17590 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
17591 gateway daemon. Its value is a @code{bitlbee-configuration} (see
17594 To have BitlBee listen on port 6667 on localhost, add this line to your
17598 (service bitlbee-service-type)
17602 @deftp {Data Type} bitlbee-configuration
17603 This is the configuration for BitlBee, with the following fields:
17606 @item @code{interface} (default: @code{"127.0.0.1"})
17607 @itemx @code{port} (default: @code{6667})
17608 Listen on the network interface corresponding to the IP address
17609 specified in @var{interface}, on @var{port}.
17611 When @var{interface} is @code{127.0.0.1}, only local clients can
17612 connect; when it is @code{0.0.0.0}, connections can come from any
17613 networking interface.
17615 @item @code{package} (default: @code{bitlbee})
17616 The BitlBee package to use.
17618 @item @code{plugins} (default: @code{'()})
17619 List of plugin packages to use---e.g., @code{bitlbee-discord}.
17621 @item @code{extra-settings} (default: @code{""})
17622 Configuration snippet added as-is to the BitlBee configuration file.
17626 @subsubheading Quassel Service
17628 @cindex IRC (Internet Relay Chat)
17629 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
17630 meaning that one or more clients can attach to and detach from the
17633 @defvr {Scheme Variable} quassel-service-type
17634 This is the service type for the @url{https://quassel-irc.org/,Quassel}
17635 IRC backend daemon. Its value is a @code{quassel-configuration}
17639 @deftp {Data Type} quassel-configuration
17640 This is the configuration for Quassel, with the following fields:
17643 @item @code{quassel} (default: @code{quassel})
17644 The Quassel package to use.
17646 @item @code{interface} (default: @code{"::,0.0.0.0"})
17647 @item @code{port} (default: @code{4242})
17648 Listen on the network interface(s) corresponding to the IPv4 or IPv6
17649 interfaces specified in the comma delimited @var{interface}, on
17652 @item @code{loglevel} (default: @code{"Info"})
17653 The level of logging desired. Accepted values are Debug, Info, Warning
17658 @node Telephony Services
17659 @subsection Telephony Services
17661 @cindex Murmur (VoIP server)
17662 @cindex VoIP server
17663 This section describes how to set up and run a Murmur server. Murmur is
17664 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
17667 @deftp {Data Type} murmur-configuration
17668 The service type for the Murmur server. An example configuration can
17672 (service murmur-service-type
17673 (murmur-configuration
17675 "Welcome to this Mumble server running on Guix!")
17676 (cert-required? #t) ;disallow text password logins
17677 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
17678 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
17681 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
17682 password with the command that is printed during the activation phase.
17684 It is recommended to register a normal Mumble user account
17685 and grant it admin or moderator rights.
17686 You can use the @code{mumble} client to
17687 login as new normal user, register yourself, and log out.
17688 For the next step login with the name @code{SuperUser} use
17689 the @code{SuperUser} password that you set previously,
17690 and grant your newly registered mumble user administrator or moderator
17691 rights and create some channels.
17693 Available @code{murmur-configuration} fields are:
17696 @item @code{package} (default: @code{mumble})
17697 Package that contains @code{bin/murmurd}.
17699 @item @code{user} (default: @code{"murmur"})
17700 User who will run the Murmur server.
17702 @item @code{group} (default: @code{"murmur"})
17703 Group of the user who will run the murmur server.
17705 @item @code{port} (default: @code{64738})
17706 Port on which the server will listen.
17708 @item @code{welcome-text} (default: @code{""})
17709 Welcome text sent to clients when they connect.
17711 @item @code{server-password} (default: @code{""})
17712 Password the clients have to enter in order to connect.
17714 @item @code{max-users} (default: @code{100})
17715 Maximum of users that can be connected to the server at once.
17717 @item @code{max-user-bandwidth} (default: @code{#f})
17718 Maximum voice traffic a user can send per second.
17720 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
17721 File name of the sqlite database.
17722 The service's user will become the owner of the directory.
17724 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
17725 File name of the log file.
17726 The service's user will become the owner of the directory.
17728 @item @code{autoban-attempts} (default: @code{10})
17729 Maximum number of logins a user can make in @code{autoban-timeframe}
17730 without getting auto banned for @code{autoban-time}.
17732 @item @code{autoban-timeframe} (default: @code{120})
17733 Timeframe for autoban in seconds.
17735 @item @code{autoban-time} (default: @code{300})
17736 Amount of time in seconds for which a client gets banned
17737 when violating the autoban limits.
17739 @item @code{opus-threshold} (default: @code{100})
17740 Percentage of clients that need to support opus
17741 before switching over to opus audio codec.
17743 @item @code{channel-nesting-limit} (default: @code{10})
17744 How deep channels can be nested at maximum.
17746 @item @code{channelname-regex} (default: @code{#f})
17747 A string in form of a Qt regular expression that channel names must conform to.
17749 @item @code{username-regex} (default: @code{#f})
17750 A string in form of a Qt regular expression that user names must conform to.
17752 @item @code{text-message-length} (default: @code{5000})
17753 Maximum size in bytes that a user can send in one text chat message.
17755 @item @code{image-message-length} (default: @code{(* 128 1024)})
17756 Maximum size in bytes that a user can send in one image message.
17758 @item @code{cert-required?} (default: @code{#f})
17759 If it is set to @code{#t} clients that use weak password authentication
17760 will not be accepted. Users must have completed the certificate wizard to join.
17762 @item @code{remember-channel?} (default: @code{#f})
17763 Should murmur remember the last channel each user was in when they disconnected
17764 and put them into the remembered channel when they rejoin.
17766 @item @code{allow-html?} (default: @code{#f})
17767 Should html be allowed in text messages, user comments, and channel descriptions.
17769 @item @code{allow-ping?} (default: @code{#f})
17770 Setting to true exposes the current user count, the maximum user count, and
17771 the server's maximum bandwidth per client to unauthenticated users. In the
17772 Mumble client, this information is shown in the Connect dialog.
17774 Disabling this setting will prevent public listing of the server.
17776 @item @code{bonjour?} (default: @code{#f})
17777 Should the server advertise itself in the local network through the bonjour protocol.
17779 @item @code{send-version?} (default: @code{#f})
17780 Should the murmur server version be exposed in ping requests.
17782 @item @code{log-days} (default: @code{31})
17783 Murmur also stores logs in the database, which are accessible via RPC.
17784 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17785 or -1 to disable logging to the database.
17787 @item @code{obfuscate-ips?} (default: @code{#t})
17788 Should logged ips be obfuscated to protect the privacy of users.
17790 @item @code{ssl-cert} (default: @code{#f})
17791 File name of the SSL/TLS certificate used for encrypted connections.
17794 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17796 @item @code{ssl-key} (default: @code{#f})
17797 Filepath to the ssl private key used for encrypted connections.
17799 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17802 @item @code{ssl-dh-params} (default: @code{#f})
17803 File name of a PEM-encoded file with Diffie-Hellman parameters
17804 for the SSL/TLS encryption. Alternatively you set it to
17805 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17806 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17808 @item @code{ssl-ciphers} (default: @code{#f})
17809 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17812 This option is specified using
17813 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17814 OpenSSL cipher list notation}.
17816 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17817 before setting it here, to get a feel for which cipher suites you will get.
17818 After setting this option, it is recommend that you inspect your Murmur log
17819 to ensure that Murmur is using the cipher suites that you expected it to.
17821 Note: Changing this option may impact the backwards compatibility of your
17822 Murmur server, and can remove the ability for older Mumble clients to be able
17825 @item @code{public-registration} (default: @code{#f})
17826 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17828 You can optionally register your server in the public server list that the
17829 @code{mumble} client shows on startup.
17830 You cannot register your server if you have set a @code{server-password},
17831 or set @code{allow-ping} to @code{#f}.
17833 It might take a few hours until it shows up in the public list.
17835 @item @code{file} (default: @code{#f})
17836 Optional alternative override for this configuration.
17840 @deftp {Data Type} murmur-public-registration-configuration
17841 Configuration for public registration of a murmur service.
17845 This is a display name for your server. Not to be confused with the hostname.
17847 @item @code{password}
17848 A password to identify your registration.
17849 Subsequent updates will need the same password. Don't lose your password.
17852 This should be a @code{http://} or @code{https://} link to your web
17855 @item @code{hostname} (default: @code{#f})
17856 By default your server will be listed by its IP address.
17857 If it is set your server will be linked by this host name instead.
17863 @node Monitoring Services
17864 @subsection Monitoring Services
17866 @subsubheading Tailon Service
17868 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17869 viewing and searching log files.
17871 The following example will configure the service with default values.
17872 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17875 (service tailon-service-type)
17878 The following example customises more of the Tailon configuration,
17879 adding @command{sed} to the list of allowed commands.
17882 (service tailon-service-type
17883 (tailon-configuration
17885 (tailon-configuration-file
17886 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17890 @deftp {Data Type} tailon-configuration
17891 Data type representing the configuration of Tailon.
17892 This type has the following parameters:
17895 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17896 The configuration file to use for Tailon. This can be set to a
17897 @dfn{tailon-configuration-file} record value, or any gexp
17898 (@pxref{G-Expressions}).
17900 For example, to instead use a local file, the @code{local-file} function
17904 (service tailon-service-type
17905 (tailon-configuration
17906 (config-file (local-file "./my-tailon.conf"))))
17909 @item @code{package} (default: @code{tailon})
17910 The tailon package to use.
17915 @deftp {Data Type} tailon-configuration-file
17916 Data type representing the configuration options for Tailon.
17917 This type has the following parameters:
17920 @item @code{files} (default: @code{(list "/var/log")})
17921 List of files to display. The list can include strings for a single file
17922 or directory, or a list, where the first item is the name of a
17923 subsection, and the remaining items are the files or directories in that
17926 @item @code{bind} (default: @code{"localhost:8080"})
17927 Address and port to which Tailon should bind on.
17929 @item @code{relative-root} (default: @code{#f})
17930 URL path to use for Tailon, set to @code{#f} to not use a path.
17932 @item @code{allow-transfers?} (default: @code{#t})
17933 Allow downloading the log files in the web interface.
17935 @item @code{follow-names?} (default: @code{#t})
17936 Allow tailing of not-yet existent files.
17938 @item @code{tail-lines} (default: @code{200})
17939 Number of lines to read initially from each file.
17941 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
17942 Commands to allow running. By default, @code{sed} is disabled.
17944 @item @code{debug?} (default: @code{#f})
17945 Set @code{debug?} to @code{#t} to show debug messages.
17947 @item @code{wrap-lines} (default: @code{#t})
17948 Initial line wrapping state in the web interface. Set to @code{#t} to
17949 initially wrap lines (the default), or to @code{#f} to initially not
17952 @item @code{http-auth} (default: @code{#f})
17953 HTTP authentication type to use. Set to @code{#f} to disable
17954 authentication (the default). Supported values are @code{"digest"} or
17957 @item @code{users} (default: @code{#f})
17958 If HTTP authentication is enabled (see @code{http-auth}), access will be
17959 restricted to the credentials provided here. To configure users, use a
17960 list of pairs, where the first element of the pair is the username, and
17961 the 2nd element of the pair is the password.
17964 (tailon-configuration-file
17965 (http-auth "basic")
17966 (users '(("user1" . "password1")
17967 ("user2" . "password2"))))
17974 @subsubheading Darkstat Service
17976 Darkstat is a packet sniffer that captures network traffic, calculates
17977 statistics about usage, and serves reports over HTTP.
17979 @defvar {Scheme Variable} darkstat-service-type
17980 This is the service type for the
17981 @uref{https://unix4lyfe.org/darkstat/, darkstat}
17982 service, its value must be a @code{darkstat-configuration} record as in
17986 (service darkstat-service-type
17987 (darkstat-configuration
17988 (interface "eno1")))
17992 @deftp {Data Type} darkstat-configuration
17993 Data type representing the configuration of @command{darkstat}.
17996 @item @code{package} (default: @code{darkstat})
17997 The darkstat package to use.
17999 @item @code{interface}
18000 Capture traffic on the specified network interface.
18002 @item @code{port} (default: @code{"667"})
18003 Bind the web interface to the specified port.
18005 @item @code{bind-address} (default: @code{"127.0.0.1"})
18006 Bind the web interface to the specified address.
18008 @item @code{base} (default: @code{"/"})
18009 Specify the path of the base URL. This can be useful if
18010 @command{darkstat} is accessed via a reverse proxy.
18015 @subsubheading Prometheus Node Exporter Service
18017 @cindex prometheus-node-exporter
18018 The Prometheus ``node exporter'' makes hardware and operating system statistics
18019 provided by the Linux kernel available for the Prometheus monitoring system.
18020 This service should be deployed on all physical nodes and virtual machines,
18021 where monitoring these statistics is desirable.
18023 @defvar {Scheme variable} prometheus-node-exporter-service-type
18024 This is the service type for the
18025 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
18026 service, its value must be a @code{prometheus-node-exporter-configuration}
18027 record as in this example:
18030 (service prometheus-node-exporter-service-type
18031 (prometheus-node-exporter-configuration
18032 (web-listen-address ":9100")))
18036 @deftp {Data Type} prometheus-node-exporter-configuration
18037 Data type representing the configuration of @command{node_exporter}.
18040 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
18041 The prometheus-node-exporter package to use.
18043 @item @code{web-listen-address} (default: @code{":9100"})
18044 Bind the web interface to the specified address.
18049 @subsubheading Zabbix server
18050 @cindex zabbix zabbix-server
18051 Zabbix provides monitoring metrics, among others network utilization, CPU load
18052 and disk space consumption:
18055 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
18056 @item Auto-discovery of servers and network devices and interfaces.
18057 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
18058 @item Distributed monitoring with centralized web administration.
18059 @item Native high performance agents.
18060 @item SLA, and ITIL KPI metrics on reporting.
18061 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
18062 @item Remote command execution through Zabbix proxies.
18065 @c %start of fragment
18067 Available @code{zabbix-server-configuration} fields are:
18069 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
18070 The zabbix-server package.
18074 @deftypevr {@code{zabbix-server-configuration} parameter} string user
18075 User who will run the Zabbix server.
18077 Defaults to @samp{"zabbix"}.
18081 @deftypevr {@code{zabbix-server-configuration} parameter} group group
18082 Group who will run the Zabbix server.
18084 Defaults to @samp{"zabbix"}.
18088 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
18089 Database host name.
18091 Defaults to @samp{"127.0.0.1"}.
18095 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
18098 Defaults to @samp{"zabbix"}.
18102 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
18105 Defaults to @samp{"zabbix"}.
18109 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
18110 Database password. Please, use @code{include-files} with
18111 @code{DBPassword=SECRET} inside a specified file instead.
18113 Defaults to @samp{""}.
18117 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
18120 Defaults to @samp{5432}.
18124 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
18125 Specifies where log messages are written to:
18129 @code{system} - syslog.
18132 @code{file} - file specified with @code{log-file} parameter.
18135 @code{console} - standard output.
18139 Defaults to @samp{""}.
18143 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
18144 Log file name for @code{log-type} @code{file} parameter.
18146 Defaults to @samp{"/var/log/zabbix/server.log"}.
18150 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
18153 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
18157 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
18158 The location of certificate authority (CA) files for SSL server
18159 certificate verification.
18161 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
18165 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
18166 Location of SSL client certificates.
18168 Defaults to @samp{"/etc/ssl/certs"}.
18172 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
18173 Extra options will be appended to Zabbix server configuration file.
18175 Defaults to @samp{""}.
18179 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
18180 You may include individual files or all files in a directory in the
18181 configuration file.
18183 Defaults to @samp{()}.
18187 @c %end of fragment
18189 @subsubheading Zabbix agent
18190 @cindex zabbix zabbix-agent
18192 Zabbix agent gathers information for Zabbix server.
18194 @c %start of fragment
18196 Available @code{zabbix-agent-configuration} fields are:
18198 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
18199 The zabbix-agent package.
18203 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
18204 User who will run the Zabbix agent.
18206 Defaults to @samp{"zabbix"}.
18210 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
18211 Group who will run the Zabbix agent.
18213 Defaults to @samp{"zabbix"}.
18217 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
18218 Unique, case sensitive hostname which is required for active checks and
18219 must match hostname as configured on the server.
18221 Defaults to @samp{"Zabbix server"}.
18225 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
18226 Specifies where log messages are written to:
18230 @code{system} - syslog.
18233 @code{file} - file specified with @code{log-file} parameter.
18236 @code{console} - standard output.
18240 Defaults to @samp{""}.
18244 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
18245 Log file name for @code{log-type} @code{file} parameter.
18247 Defaults to @samp{"/var/log/zabbix/agent.log"}.
18251 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
18254 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
18258 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
18259 List of IP addresses, optionally in CIDR notation, or hostnames of
18260 Zabbix servers and Zabbix proxies. Incoming connections will be
18261 accepted only from the hosts listed here.
18263 Defaults to @samp{("127.0.0.1")}.
18267 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
18268 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
18269 proxies for active checks. If port is not specified, default port is
18270 used. If this parameter is not specified, active checks are disabled.
18272 Defaults to @samp{("127.0.0.1")}.
18276 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
18277 Extra options will be appended to Zabbix server configuration file.
18279 Defaults to @samp{""}.
18283 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
18284 You may include individual files or all files in a directory in the
18285 configuration file.
18287 Defaults to @samp{()}.
18291 @c %end of fragment
18293 @subsubheading Zabbix front-end
18294 @cindex zabbix zabbix-front-end
18296 This service provides a WEB interface to Zabbix server.
18298 @c %start of fragment
18300 Available @code{zabbix-front-end-configuration} fields are:
18302 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
18303 NGINX configuration.
18307 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
18308 Database host name.
18310 Defaults to @samp{"localhost"}.
18314 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
18317 Defaults to @samp{5432}.
18321 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
18324 Defaults to @samp{"zabbix"}.
18328 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
18331 Defaults to @samp{"zabbix"}.
18335 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
18336 Database password. Please, use @code{db-secret-file} instead.
18338 Defaults to @samp{""}.
18342 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
18343 Secret file which will be appended to @file{zabbix.conf.php} file. This
18344 file contains credentials for use by Zabbix front-end. You are expected
18345 to create it manually.
18347 Defaults to @samp{""}.
18351 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
18352 Zabbix server hostname.
18354 Defaults to @samp{"localhost"}.
18358 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
18359 Zabbix server port.
18361 Defaults to @samp{10051}.
18366 @c %end of fragment
18368 @node Kerberos Services
18369 @subsection Kerberos Services
18372 The @code{(gnu services kerberos)} module provides services relating to
18373 the authentication protocol @dfn{Kerberos}.
18375 @subsubheading Krb5 Service
18377 Programs using a Kerberos client library normally
18378 expect a configuration file in @file{/etc/krb5.conf}.
18379 This service generates such a file from a definition provided in the
18380 operating system declaration.
18381 It does not cause any daemon to be started.
18383 No ``keytab'' files are provided by this service---you must explicitly create them.
18384 This service is known to work with the MIT client library, @code{mit-krb5}.
18385 Other implementations have not been tested.
18387 @defvr {Scheme Variable} krb5-service-type
18388 A service type for Kerberos 5 clients.
18392 Here is an example of its use:
18394 (service krb5-service-type
18395 (krb5-configuration
18396 (default-realm "EXAMPLE.COM")
18397 (allow-weak-crypto? #t)
18400 (name "EXAMPLE.COM")
18401 (admin-server "groucho.example.com")
18402 (kdc "karl.example.com"))
18405 (admin-server "kerb-admin.argrx.edu")
18406 (kdc "keys.argrx.edu"))))))
18410 This example provides a Kerberos@tie{}5 client configuration which:
18412 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
18413 of which have distinct administration servers and key distribution centers;
18414 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
18415 specified by clients;
18416 @item Accepts services which only support encryption types known to be weak.
18419 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
18420 Only the most commonly used ones are described here.
18421 For a full list, and more detailed explanation of each, see the MIT
18422 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
18426 @deftp {Data Type} krb5-realm
18427 @cindex realm, kerberos
18430 This field is a string identifying the name of the realm.
18431 A common convention is to use the fully qualified DNS name of your organization,
18432 converted to upper case.
18434 @item @code{admin-server}
18435 This field is a string identifying the host where the administration server is
18439 This field is a string identifying the key distribution center
18444 @deftp {Data Type} krb5-configuration
18447 @item @code{allow-weak-crypto?} (default: @code{#f})
18448 If this flag is @code{#t} then services which only offer encryption algorithms
18449 known to be weak will be accepted.
18451 @item @code{default-realm} (default: @code{#f})
18452 This field should be a string identifying the default Kerberos
18453 realm for the client.
18454 You should set this field to the name of your Kerberos realm.
18455 If this value is @code{#f}
18456 then a realm must be specified with every Kerberos principal when invoking programs
18457 such as @command{kinit}.
18459 @item @code{realms}
18460 This should be a non-empty list of @code{krb5-realm} objects, which clients may
18462 Normally, one of them will have a @code{name} field matching the @code{default-realm}
18468 @subsubheading PAM krb5 Service
18471 The @code{pam-krb5} service allows for login authentication and password
18472 management via Kerberos.
18473 You will need this service if you want PAM enabled applications to authenticate
18474 users using Kerberos.
18476 @defvr {Scheme Variable} pam-krb5-service-type
18477 A service type for the Kerberos 5 PAM module.
18480 @deftp {Data Type} pam-krb5-configuration
18481 Data type representing the configuration of the Kerberos 5 PAM module.
18482 This type has the following parameters:
18484 @item @code{pam-krb5} (default: @code{pam-krb5})
18485 The pam-krb5 package to use.
18487 @item @code{minimum-uid} (default: @code{1000})
18488 The smallest user ID for which Kerberos authentications should be attempted.
18489 Local accounts with lower values will silently fail to authenticate.
18494 @node LDAP Services
18495 @subsection LDAP Services
18497 @cindex nslcd, LDAP service
18499 The @code{(gnu services authentication)} module provides the
18500 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
18501 server. In addition to configuring the service itself, you may want to add
18502 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
18503 Switch} for detailed information.
18505 Here is a simple operating system declaration with a default configuration of
18506 the @code{nslcd-service-type} and a Name Service Switch configuration that
18507 consults the @code{ldap} name service last:
18510 (use-service-modules authentication)
18511 (use-modules (gnu system nss))
18517 (service nslcd-service-type)
18518 (service dhcp-client-service-type)
18520 (name-service-switch
18521 (let ((services (list (name-service (name "db"))
18522 (name-service (name "files"))
18523 (name-service (name "ldap")))))
18524 (name-service-switch
18525 (inherit %mdns-host-lookup-nss)
18526 (password services)
18529 (netgroup services)
18530 (gshadow services)))))
18533 @c %start of generated documentation for nslcd-configuration
18535 Available @code{nslcd-configuration} fields are:
18537 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
18538 The @code{nss-pam-ldapd} package to use.
18542 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
18543 The number of threads to start that can handle requests and perform LDAP
18544 queries. Each thread opens a separate connection to the LDAP server.
18545 The default is to start 5 threads.
18547 Defaults to @samp{disabled}.
18551 @deftypevr {@code{nslcd-configuration} parameter} string uid
18552 This specifies the user id with which the daemon should be run.
18554 Defaults to @samp{"nslcd"}.
18558 @deftypevr {@code{nslcd-configuration} parameter} string gid
18559 This specifies the group id with which the daemon should be run.
18561 Defaults to @samp{"nslcd"}.
18565 @deftypevr {@code{nslcd-configuration} parameter} log-option log
18566 This option controls the way logging is done via a list containing
18567 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
18568 or "syslog", or an absolute file name. The LEVEL argument is optional
18569 and specifies the log level. The log level may be one of the following
18570 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
18571 messages with the specified log level or higher are logged.
18573 Defaults to @samp{("/var/log/nslcd" info)}.
18577 @deftypevr {@code{nslcd-configuration} parameter} list uri
18578 The list of LDAP server URIs. Normally, only the first server will be
18579 used with the following servers as fall-back.
18581 Defaults to @samp{("ldap://localhost:389/")}.
18585 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
18586 The version of the LDAP protocol to use. The default is to use the
18587 maximum version supported by the LDAP library.
18589 Defaults to @samp{disabled}.
18593 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
18594 Specifies the distinguished name with which to bind to the directory
18595 server for lookups. The default is to bind anonymously.
18597 Defaults to @samp{disabled}.
18601 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
18602 Specifies the credentials with which to bind. This option is only
18603 applicable when used with binddn.
18605 Defaults to @samp{disabled}.
18609 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
18610 Specifies the distinguished name to use when the root user tries to
18611 modify a user's password using the PAM module.
18613 Defaults to @samp{disabled}.
18617 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
18618 Specifies the credentials with which to bind if the root user tries to
18619 change a user's password. This option is only applicable when used with
18622 Defaults to @samp{disabled}.
18626 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
18627 Specifies the SASL mechanism to be used when performing SASL
18630 Defaults to @samp{disabled}.
18634 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
18635 Specifies the SASL realm to be used when performing SASL authentication.
18637 Defaults to @samp{disabled}.
18641 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
18642 Specifies the authentication identity to be used when performing SASL
18645 Defaults to @samp{disabled}.
18649 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
18650 Specifies the authorization identity to be used when performing SASL
18653 Defaults to @samp{disabled}.
18657 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
18658 Determines whether the LDAP server host name should be canonicalised. If
18659 this is enabled the LDAP library will do a reverse host name lookup. By
18660 default, it is left up to the LDAP library whether this check is
18663 Defaults to @samp{disabled}.
18667 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
18668 Set the name for the GSS-API Kerberos credentials cache.
18670 Defaults to @samp{disabled}.
18674 @deftypevr {@code{nslcd-configuration} parameter} string base
18675 The directory search base.
18677 Defaults to @samp{"dc=example,dc=com"}.
18681 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
18682 Specifies the search scope (subtree, onelevel, base or children). The
18683 default scope is subtree; base scope is almost never useful for name
18684 service lookups; children scope is not supported on all servers.
18686 Defaults to @samp{(subtree)}.
18690 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
18691 Specifies the policy for dereferencing aliases. The default policy is
18692 to never dereference aliases.
18694 Defaults to @samp{disabled}.
18698 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
18699 Specifies whether automatic referral chasing should be enabled. The
18700 default behaviour is to chase referrals.
18702 Defaults to @samp{disabled}.
18706 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
18707 This option allows for custom attributes to be looked up instead of the
18708 default RFC 2307 attributes. It is a list of maps, each consisting of
18709 the name of a map, the RFC 2307 attribute to match and the query
18710 expression for the attribute as it is available in the directory.
18712 Defaults to @samp{()}.
18716 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
18717 A list of filters consisting of the name of a map to which the filter
18718 applies and an LDAP search filter expression.
18720 Defaults to @samp{()}.
18724 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
18725 Specifies the time limit in seconds to use when connecting to the
18726 directory server. The default value is 10 seconds.
18728 Defaults to @samp{disabled}.
18732 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
18733 Specifies the time limit (in seconds) to wait for a response from the
18734 LDAP server. A value of zero, which is the default, is to wait
18735 indefinitely for searches to be completed.
18737 Defaults to @samp{disabled}.
18741 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
18742 Specifies the period if inactivity (in seconds) after which the con‐
18743 nection to the LDAP server will be closed. The default is not to time
18746 Defaults to @samp{disabled}.
18750 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
18751 Specifies the number of seconds to sleep when connecting to all LDAP
18752 servers fails. By default one second is waited between the first
18753 failure and the first retry.
18755 Defaults to @samp{disabled}.
18759 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
18760 Specifies the time after which the LDAP server is considered to be
18761 permanently unavailable. Once this time is reached retries will be done
18762 only once per this time period. The default value is 10 seconds.
18764 Defaults to @samp{disabled}.
18768 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
18769 Specifies whether to use SSL/TLS or not (the default is not to). If
18770 'start-tls is specified then StartTLS is used rather than raw LDAP over
18773 Defaults to @samp{disabled}.
18777 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18778 Specifies what checks to perform on a server-supplied certificate. The
18779 meaning of the values is described in the ldap.conf(5) manual page.
18781 Defaults to @samp{disabled}.
18785 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18786 Specifies the directory containing X.509 certificates for peer authen‐
18787 tication. This parameter is ignored when using GnuTLS.
18789 Defaults to @samp{disabled}.
18793 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18794 Specifies the path to the X.509 certificate for peer authentication.
18796 Defaults to @samp{disabled}.
18800 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18801 Specifies the path to an entropy source. This parameter is ignored when
18804 Defaults to @samp{disabled}.
18808 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18809 Specifies the ciphers to use for TLS as a string.
18811 Defaults to @samp{disabled}.
18815 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18816 Specifies the path to the file containing the local certificate for
18817 client TLS authentication.
18819 Defaults to @samp{disabled}.
18823 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18824 Specifies the path to the file containing the private key for client TLS
18827 Defaults to @samp{disabled}.
18831 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18832 Set this to a number greater than 0 to request paged results from the
18833 LDAP server in accordance with RFC2696. The default (0) is to not
18834 request paged results.
18836 Defaults to @samp{disabled}.
18840 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18841 This option prevents group membership lookups through LDAP for the
18842 specified users. Alternatively, the value 'all-local may be used. With
18843 that value nslcd builds a full list of non-LDAP users on startup.
18845 Defaults to @samp{disabled}.
18849 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18850 This option ensures that LDAP users with a numeric user id lower than
18851 the specified value are ignored.
18853 Defaults to @samp{disabled}.
18857 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18858 This option specifies an offset that is added to all LDAP numeric user
18859 ids. This can be used to avoid user id collisions with local users.
18861 Defaults to @samp{disabled}.
18865 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18866 This option specifies an offset that is added to all LDAP numeric group
18867 ids. This can be used to avoid user id collisions with local groups.
18869 Defaults to @samp{disabled}.
18873 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18874 If this option is set, the member attribute of a group may point to
18875 another group. Members of nested groups are also returned in the higher
18876 level group and parent groups are returned when finding groups for a
18877 specific user. The default is not to perform extra searches for nested
18880 Defaults to @samp{disabled}.
18884 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18885 If this option is set, the group member list is not retrieved when
18886 looking up groups. Lookups for finding which groups a user belongs to
18887 will remain functional so the user will likely still get the correct
18888 groups assigned on login.
18890 Defaults to @samp{disabled}.
18894 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18895 If this option is set, functions which cause all user/group entries to
18896 be loaded from the directory will not succeed in doing so. This can
18897 dramatically reduce LDAP server load in situations where there are a
18898 great number of users and/or groups. This option is not recommended for
18899 most configurations.
18901 Defaults to @samp{disabled}.
18905 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
18906 This option can be used to specify how user and group names are verified
18907 within the system. This pattern is used to check all user and group
18908 names that are requested and returned from LDAP.
18910 Defaults to @samp{disabled}.
18914 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
18915 This specifies whether or not to perform searches using case-insensitive
18916 matching. Enabling this could open up the system to authorization
18917 bypass vulnerabilities and introduce nscd cache poisoning
18918 vulnerabilities which allow denial of service.
18920 Defaults to @samp{disabled}.
18924 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
18925 This option specifies whether password policy controls are requested and
18926 handled from the LDAP server when performing user authentication.
18928 Defaults to @samp{disabled}.
18932 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
18933 By default nslcd performs an LDAP search with the user's credentials
18934 after BIND (authentication) to ensure that the BIND operation was
18935 successful. The default search is a simple check to see if the user's
18936 DN exists. A search filter can be specified that will be used instead.
18937 It should return at least one entry.
18939 Defaults to @samp{disabled}.
18943 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
18944 This option allows flexible fine tuning of the authorisation check that
18945 should be performed. The search filter specified is executed and if any
18946 entries match, access is granted, otherwise access is denied.
18948 Defaults to @samp{disabled}.
18952 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
18953 If this option is set password modification using pam_ldap will be
18954 denied and the specified message will be presented to the user instead.
18955 The message can be used to direct the user to an alternative means of
18956 changing their password.
18958 Defaults to @samp{disabled}.
18962 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
18963 List of pam service names for which LDAP authentication should suffice.
18965 Defaults to @samp{()}.
18969 @c %end of generated documentation for nslcd-configuration
18973 @subsection Web Services
18978 The @code{(gnu services web)} module provides the Apache HTTP Server,
18979 the nginx web server, and also a fastcgi wrapper daemon.
18981 @subsubheading Apache HTTP Server
18983 @deffn {Scheme Variable} httpd-service-type
18984 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
18985 (@dfn{httpd}). The value for this service type is a
18986 @code{httpd-configuration} record.
18988 A simple example configuration is given below.
18991 (service httpd-service-type
18992 (httpd-configuration
18995 (server-name "www.example.com")
18996 (document-root "/srv/http/www.example.com")))))
18999 Other services can also extend the @code{httpd-service-type} to add to
19003 (simple-service 'my-extra-server httpd-service-type
19007 (list (string-append
19008 "ServerName "www.example.com
19009 DocumentRoot \"/srv/http/www.example.com\"")))))
19013 The details for the @code{httpd-configuration}, @code{httpd-module},
19014 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
19017 @deffn {Data Type} httpd-configuration
19018 This data type represents the configuration for the httpd service.
19021 @item @code{package} (default: @code{httpd})
19022 The httpd package to use.
19024 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19025 The pid file used by the shepherd-service.
19027 @item @code{config} (default: @code{(httpd-config-file)})
19028 The configuration file to use with the httpd service. The default value
19029 is a @code{httpd-config-file} record, but this can also be a different
19030 G-expression that generates a file, for example a @code{plain-file}. A
19031 file outside of the store can also be specified through a string.
19036 @deffn {Data Type} httpd-module
19037 This data type represents a module for the httpd service.
19041 The name of the module.
19044 The file for the module. This can be relative to the httpd package being
19045 used, the absolute location of a file, or a G-expression for a file
19046 within the store, for example @code{(file-append mod-wsgi
19047 "/modules/mod_wsgi.so")}.
19052 @defvr {Scheme Variable} %default-httpd-modules
19053 A default list of @code{httpd-module} objects.
19056 @deffn {Data Type} httpd-config-file
19057 This data type represents a configuration file for the httpd service.
19060 @item @code{modules} (default: @code{%default-httpd-modules})
19061 The modules to load. Additional modules can be added here, or loaded by
19062 additional configuration.
19064 For example, in order to handle requests for PHP files, you can use Apache’s
19065 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
19068 (service httpd-service-type
19069 (httpd-configuration
19074 (name "proxy_module")
19075 (file "modules/mod_proxy.so"))
19077 (name "proxy_fcgi_module")
19078 (file "modules/mod_proxy_fcgi.so"))
19079 %default-httpd-modules))
19080 (extra-config (list "\
19081 <FilesMatch \\.php$>
19082 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
19083 </FilesMatch>"))))))
19084 (service php-fpm-service-type
19085 (php-fpm-configuration
19086 (socket "/var/run/php-fpm.sock")
19087 (socket-group "httpd")))
19090 @item @code{server-root} (default: @code{httpd})
19091 The @code{ServerRoot} in the configuration file, defaults to the httpd
19092 package. Directives including @code{Include} and @code{LoadModule} are
19093 taken as relative to the server root.
19095 @item @code{server-name} (default: @code{#f})
19096 The @code{ServerName} in the configuration file, used to specify the
19097 request scheme, hostname and port that the server uses to identify
19100 This doesn't need to be set in the server config, and can be specifyed
19101 in virtual hosts. The default is @code{#f} to not specify a
19104 @item @code{document-root} (default: @code{"/srv/http"})
19105 The @code{DocumentRoot} from which files will be served.
19107 @item @code{listen} (default: @code{'("80")})
19108 The list of values for the @code{Listen} directives in the config
19109 file. The value should be a list of strings, when each string can
19110 specify the port number to listen on, and optionally the IP address and
19113 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19114 The @code{PidFile} to use. This should match the @code{pid-file} set in
19115 the @code{httpd-configuration} so that the Shepherd service is
19116 configured correctly.
19118 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
19119 The @code{ErrorLog} to which the server will log errors.
19121 @item @code{user} (default: @code{"httpd"})
19122 The @code{User} which the server will answer requests as.
19124 @item @code{group} (default: @code{"httpd"})
19125 The @code{Group} which the server will answer requests as.
19127 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
19128 A flat list of strings and G-expressions which will be added to the end
19129 of the configuration file.
19131 Any values which the service is extended with will be appended to this
19137 @deffn {Data Type} httpd-virtualhost
19138 This data type represents a virtualhost configuration block for the httpd service.
19140 These should be added to the extra-config for the httpd-service.
19143 (simple-service 'my-extra-server httpd-service-type
19147 (list (string-append
19148 "ServerName "www.example.com
19149 DocumentRoot \"/srv/http/www.example.com\"")))))
19153 @item @code{addresses-and-ports}
19154 The addresses and ports for the @code{VirtualHost} directive.
19156 @item @code{contents}
19157 The contents of the @code{VirtualHost} directive, this should be a list
19158 of strings and G-expressions.
19163 @subsubheading NGINX
19165 @deffn {Scheme Variable} nginx-service-type
19166 Service type for the @uref{https://nginx.org/,NGinx} web server. The
19167 value for this service type is a @code{<nginx-configuration>} record.
19169 A simple example configuration is given below.
19172 (service nginx-service-type
19173 (nginx-configuration
19175 (list (nginx-server-configuration
19176 (server-name '("www.example.com"))
19177 (root "/srv/http/www.example.com"))))))
19180 In addition to adding server blocks to the service configuration
19181 directly, this service can be extended by other services to add server
19182 blocks, as in this example:
19185 (simple-service 'my-extra-server nginx-service-type
19186 (list (nginx-server-configuration
19187 (root "/srv/http/extra-website")
19188 (try-files (list "$uri" "$uri/index.html")))))
19192 At startup, @command{nginx} has not yet read its configuration file, so
19193 it uses a default file to log error messages. If it fails to load its
19194 configuration file, that is where error messages are logged. After the
19195 configuration file is loaded, the default error log file changes as per
19196 configuration. In our case, startup error messages can be found in
19197 @file{/var/run/nginx/logs/error.log}, and after configuration in
19198 @file{/var/log/nginx/error.log}. The second location can be changed
19199 with the @var{log-directory} configuration option.
19201 @deffn {Data Type} nginx-configuration
19202 This data type represents the configuration for NGinx. Some
19203 configuration can be done through this and the other provided record
19204 types, or alternatively, a config file can be provided.
19207 @item @code{nginx} (default: @code{nginx})
19208 The nginx package to use.
19210 @item @code{log-directory} (default: @code{"/var/log/nginx"})
19211 The directory to which NGinx will write log files.
19213 @item @code{run-directory} (default: @code{"/var/run/nginx"})
19214 The directory in which NGinx will create a pid file, and write temporary
19217 @item @code{server-blocks} (default: @code{'()})
19218 A list of @dfn{server blocks} to create in the generated configuration
19219 file, the elements should be of type
19220 @code{<nginx-server-configuration>}.
19222 The following example would setup NGinx to serve @code{www.example.com}
19223 from the @code{/srv/http/www.example.com} directory, without using
19226 (service nginx-service-type
19227 (nginx-configuration
19229 (list (nginx-server-configuration
19230 (server-name '("www.example.com"))
19231 (root "/srv/http/www.example.com"))))))
19234 @item @code{upstream-blocks} (default: @code{'()})
19235 A list of @dfn{upstream blocks} to create in the generated configuration
19236 file, the elements should be of type
19237 @code{<nginx-upstream-configuration>}.
19239 Configuring upstreams through the @code{upstream-blocks} can be useful
19240 when combined with @code{locations} in the
19241 @code{<nginx-server-configuration>} records. The following example
19242 creates a server configuration with one location configuration, that
19243 will proxy requests to a upstream configuration, which will handle
19244 requests with two servers.
19249 (nginx-configuration
19251 (list (nginx-server-configuration
19252 (server-name '("www.example.com"))
19253 (root "/srv/http/www.example.com")
19256 (nginx-location-configuration
19258 (body '("proxy_pass http://server-proxy;"))))))))
19260 (list (nginx-upstream-configuration
19261 (name "server-proxy")
19262 (servers (list "server1.example.com"
19263 "server2.example.com")))))))
19266 @item @code{file} (default: @code{#f})
19267 If a configuration @var{file} is provided, this will be used, rather than
19268 generating a configuration file from the provided @code{log-directory},
19269 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
19270 proper operation, these arguments should match what is in @var{file} to ensure
19271 that the directories are created when the service is activated.
19273 This can be useful if you have an existing configuration file, or it's
19274 not possible to do what is required through the other parts of the
19275 nginx-configuration record.
19277 @item @code{server-names-hash-bucket-size} (default: @code{#f})
19278 Bucket size for the server names hash tables, defaults to @code{#f} to
19279 use the size of the processors cache line.
19281 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
19282 Maximum bucket size for the server names hash tables.
19284 @item @code{extra-content} (default: @code{""})
19285 Extra content for the @code{http} block. Should be string or a string
19286 valued G-expression.
19291 @deftp {Data Type} nginx-server-configuration
19292 Data type representing the configuration of an nginx server block.
19293 This type has the following parameters:
19296 @item @code{listen} (default: @code{'("80" "443 ssl")})
19297 Each @code{listen} directive sets the address and port for IP, or the
19298 path for a UNIX-domain socket on which the server will accept requests.
19299 Both address and port, or only address or only port can be specified.
19300 An address may also be a hostname, for example:
19303 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
19306 @item @code{server-name} (default: @code{(list 'default)})
19307 A list of server names this server represents. @code{'default} represents the
19308 default server for connections matching no other server.
19310 @item @code{root} (default: @code{"/srv/http"})
19311 Root of the website nginx will serve.
19313 @item @code{locations} (default: @code{'()})
19314 A list of @dfn{nginx-location-configuration} or
19315 @dfn{nginx-named-location-configuration} records to use within this
19318 @item @code{index} (default: @code{(list "index.html")})
19319 Index files to look for when clients ask for a directory. If it cannot be found,
19320 Nginx will send the list of files in the directory.
19322 @item @code{try-files} (default: @code{'()})
19323 A list of files whose existence is checked in the specified order.
19324 @code{nginx} will use the first file it finds to process the request.
19326 @item @code{ssl-certificate} (default: @code{#f})
19327 Where to find the certificate for secure connections. Set it to @code{#f} if
19328 you don't have a certificate or you don't want to use HTTPS.
19330 @item @code{ssl-certificate-key} (default: @code{#f})
19331 Where to find the private key for secure connections. Set it to @code{#f} if
19332 you don't have a key or you don't want to use HTTPS.
19334 @item @code{server-tokens?} (default: @code{#f})
19335 Whether the server should add its configuration to response.
19337 @item @code{raw-content} (default: @code{'()})
19338 A list of raw lines added to the server block.
19343 @deftp {Data Type} nginx-upstream-configuration
19344 Data type representing the configuration of an nginx @code{upstream}
19345 block. This type has the following parameters:
19349 Name for this group of servers.
19351 @item @code{servers}
19352 Specify the addresses of the servers in the group. The address can be
19353 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
19354 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
19355 prefix @samp{unix:}. For addresses using an IP address or domain name,
19356 the default port is 80, and a different port can be specified
19362 @deftp {Data Type} nginx-location-configuration
19363 Data type representing the configuration of an nginx @code{location}
19364 block. This type has the following parameters:
19368 URI which this location block matches.
19370 @anchor{nginx-location-configuration body}
19372 Body of the location block, specified as a list of strings. This can contain
19374 configuration directives. For example, to pass requests to a upstream
19375 server group defined using an @code{nginx-upstream-configuration} block,
19376 the following directive would be specified in the body @samp{(list "proxy_pass
19377 http://upstream-name;")}.
19382 @deftp {Data Type} nginx-named-location-configuration
19383 Data type representing the configuration of an nginx named location
19384 block. Named location blocks are used for request redirection, and not
19385 used for regular request processing. This type has the following
19390 Name to identify this location block.
19393 @xref{nginx-location-configuration body}, as the body for named location
19394 blocks can be used in a similar way to the
19395 @code{nginx-location-configuration body}. One restriction is that the
19396 body of a named location block cannot contain location blocks.
19401 @subsubheading Varnish Cache
19403 Varnish is a fast cache server that sits in between web applications
19404 and end users. It proxies requests from clients and caches the
19405 accessed URLs such that multiple requests for the same resource only
19406 creates one request to the back-end.
19408 @defvr {Scheme Variable} varnish-service-type
19409 Service type for the Varnish daemon.
19412 @deftp {Data Type} varnish-configuration
19413 Data type representing the @code{varnish} service configuration.
19414 This type has the following parameters:
19417 @item @code{package} (default: @code{varnish})
19418 The Varnish package to use.
19420 @item @code{name} (default: @code{"default"})
19421 A name for this Varnish instance. Varnish will create a directory in
19422 @file{/var/varnish/} with this name and keep temporary files there. If
19423 the name starts with a forward slash, it is interpreted as an absolute
19426 Pass the @code{-n} argument to other Varnish programs to connect to the
19427 named instance, e.g.@: @command{varnishncsa -n default}.
19429 @item @code{backend} (default: @code{"localhost:8080"})
19430 The backend to use. This option has no effect if @code{vcl} is set.
19432 @item @code{vcl} (default: #f)
19433 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
19434 is @code{#f}, Varnish will proxy @code{backend} using the default
19435 configuration. Otherwise this must be a file-like object with valid
19438 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
19439 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
19440 can do something along these lines:
19443 (define %gnu-mirror
19447 backend gnu @{ .host = "www.gnu.org"; @}"))
19451 (services (cons (service varnish-service-type
19452 (varnish-configuration
19454 (vcl %gnu-mirror)))
19458 The configuration of an already running Varnish instance can be inspected
19459 and changed using the @command{varnishadm} program.
19461 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
19462 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
19463 comprehensive documentation on Varnish and its configuration language.
19465 @item @code{listen} (default: @code{'("localhost:80")})
19466 List of addresses Varnish will listen on.
19468 @item @code{storage} (default: @code{'("malloc,128m")})
19469 List of storage backends that will be available in VCL.
19471 @item @code{parameters} (default: @code{'()})
19472 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
19474 @item @code{extra-options} (default: @code{'()})
19475 Additional arguments to pass to the @command{varnishd} process.
19480 @subsubheading Patchwork
19482 Patchwork is a patch tracking system. It can collect patches sent to a
19483 mailing list, and display them in a web interface.
19485 @defvr {Scheme Variable} patchwork-service-type
19486 Service type for Patchwork.
19489 The following example is an example of a minimal service for Patchwork, for
19490 the @code{patchwork.example.com} domain.
19493 (service patchwork-service-type
19494 (patchwork-configuration
19495 (domain "patchwork.example.com")
19497 (patchwork-settings-module
19498 (allowed-hosts (list domain))
19499 (default-from-email "patchwork@@patchwork.example.com")))
19500 (getmail-retriever-config
19501 (getmail-retriever-configuration
19502 (type "SimpleIMAPSSLRetriever")
19503 (server "imap.example.com")
19505 (username "patchwork")
19507 (list (file-append coreutils "/bin/cat")
19508 "/etc/getmail-patchwork-imap-password"))
19510 '((mailboxes . ("Patches"))))))))
19514 There are three records for configuring the Patchwork service. The
19515 @code{<patchwork-configuration>} relates to the configuration for Patchwork
19516 within the HTTPD service.
19518 The @code{settings-module} field within the @code{<patchwork-configuration>}
19519 record can be populated with the @code{<patchwork-settings-module>} record,
19520 which describes a settings module that is generated within the Guix store.
19522 For the @code{database-configuration} field within the
19523 @code{<patchwork-settings-module>}, the
19524 @code{<patchwork-database-configuration>} must be used.
19526 @deftp {Data Type} patchwork-configuration
19527 Data type representing the Patchwork service configuration. This type has the
19528 following parameters:
19531 @item @code{patchwork} (default: @code{patchwork})
19532 The Patchwork package to use.
19534 @item @code{domain}
19535 The domain to use for Patchwork, this is used in the HTTPD service virtual
19538 @item @code{settings-module}
19539 The settings module to use for Patchwork. As a Django application, Patchwork
19540 is configured with a Python module containing the settings. This can either be
19541 an instance of the @code{<patchwork-settings-module>} record, any other record
19542 that represents the settings in the store, or a directory outside of the
19545 @item @code{static-path} (default: @code{"/static/"})
19546 The path under which the HTTPD service should serve the static files.
19548 @item @code{getmail-retriever-config}
19549 The getmail-retriever-configuration record value to use with
19550 Patchwork. Getmail will be configured with this value, the messages will be
19551 delivered to Patchwork.
19556 @deftp {Data Type} patchwork-settings-module
19557 Data type representing a settings module for Patchwork. Some of these
19558 settings relate directly to Patchwork, but others relate to Django, the web
19559 framework used by Patchwork, or the Django Rest Framework library. This type
19560 has the following parameters:
19563 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
19564 The database connection settings used for Patchwork. See the
19565 @code{<patchwork-database-configuration>} record type for more information.
19567 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
19568 Patchwork, as a Django web application uses a secret key for cryptographically
19569 signing values. This file should contain a unique unpredictable value.
19571 If this file does not exist, it will be created and populated with a random
19572 value by the patchwork-setup shepherd service.
19574 This setting relates to Django.
19576 @item @code{allowed-hosts}
19577 A list of valid hosts for this Patchwork service. This should at least include
19578 the domain specified in the @code{<patchwork-configuration>} record.
19580 This is a Django setting.
19582 @item @code{default-from-email}
19583 The email address from which Patchwork should send email by default.
19585 This is a Patchwork setting.
19587 @item @code{static-url} (default: @code{#f})
19588 The URL to use when serving static assets. It can be part of a URL, or a full
19589 URL, but must end in a @code{/}.
19591 If the default value is used, the @code{static-path} value from the
19592 @code{<patchwork-configuration>} record will be used.
19594 This is a Django setting.
19596 @item @code{admins} (default: @code{'()})
19597 Email addresses to send the details of errors that occur. Each value should
19598 be a list containing two elements, the name and then the email address.
19600 This is a Django setting.
19602 @item @code{debug?} (default: @code{#f})
19603 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
19604 messages will be shown.
19606 This is a Django setting.
19608 @item @code{enable-rest-api?} (default: @code{#t})
19609 Whether to enable the Patchwork REST API.
19611 This is a Patchwork setting.
19613 @item @code{enable-xmlrpc?} (default: @code{#t})
19614 Whether to enable the XML RPC API.
19616 This is a Patchwork setting.
19618 @item @code{force-https-links?} (default: @code{#t})
19619 Whether to use HTTPS links on Patchwork pages.
19621 This is a Patchwork setting.
19623 @item @code{extra-settings} (default: @code{""})
19624 Extra code to place at the end of the Patchwork settings module.
19629 @deftp {Data Type} patchwork-database-configuration
19630 Data type representing the database configuration for Patchwork.
19633 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
19634 The database engine to use.
19636 @item @code{name} (default: @code{"patchwork"})
19637 The name of the database to use.
19639 @item @code{user} (default: @code{"httpd"})
19640 The user to connect to the database as.
19642 @item @code{password} (default: @code{""})
19643 The password to use when connecting to the database.
19645 @item @code{host} (default: @code{""})
19646 The host to make the database connection to.
19648 @item @code{port} (default: @code{""})
19649 The port on which to connect to the database.
19654 @subsubheading FastCGI
19657 FastCGI is an interface between the front-end and the back-end of a web
19658 service. It is a somewhat legacy facility; new web services should
19659 generally just talk HTTP between the front-end and the back-end.
19660 However there are a number of back-end services such as PHP or the
19661 optimized HTTP Git repository access that use FastCGI, so we have
19662 support for it in Guix.
19664 To use FastCGI, you configure the front-end web server (e.g., nginx) to
19665 dispatch some subset of its requests to the fastcgi backend, which
19666 listens on a local TCP or UNIX socket. There is an intermediary
19667 @code{fcgiwrap} program that sits between the actual backend process and
19668 the web server. The front-end indicates which backend program to run,
19669 passing that information to the @code{fcgiwrap} process.
19671 @defvr {Scheme Variable} fcgiwrap-service-type
19672 A service type for the @code{fcgiwrap} FastCGI proxy.
19675 @deftp {Data Type} fcgiwrap-configuration
19676 Data type representing the configuration of the @code{fcgiwrap} service.
19677 This type has the following parameters:
19679 @item @code{package} (default: @code{fcgiwrap})
19680 The fcgiwrap package to use.
19682 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
19683 The socket on which the @code{fcgiwrap} process should listen, as a
19684 string. Valid @var{socket} values include
19685 @code{unix:@var{/path/to/unix/socket}},
19686 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
19687 @code{tcp6:[@var{ipv6_addr}]:port}.
19689 @item @code{user} (default: @code{fcgiwrap})
19690 @itemx @code{group} (default: @code{fcgiwrap})
19691 The user and group names, as strings, under which to run the
19692 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
19693 the user asks for the specific user or group names @code{fcgiwrap} that
19694 the corresponding user and/or group is present on the system.
19696 It is possible to configure a FastCGI-backed web service to pass HTTP
19697 authentication information from the front-end to the back-end, and to
19698 allow @code{fcgiwrap} to run the back-end process as a corresponding
19699 local user. To enable this capability on the back-end., run
19700 @code{fcgiwrap} as the @code{root} user and group. Note that this
19701 capability also has to be configured on the front-end as well.
19706 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
19707 with some additional features useful for sites of any size.
19709 These features include:
19711 @item Adaptive process spawning
19712 @item Basic statistics (similar to Apache's mod_status)
19713 @item Advanced process management with graceful stop/start
19714 @item Ability to start workers with different uid/gid/chroot/environment
19715 and different php.ini (replaces safe_mode)
19716 @item Stdout & stderr logging
19717 @item Emergency restart in case of accidental opcode cache destruction
19718 @item Accelerated upload support
19719 @item Support for a "slowlog"
19720 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
19721 a special function to finish request & flush all data while continuing to do
19722 something time-consuming (video converting, stats processing, etc.)
19724 ...@: and much more.
19726 @defvr {Scheme Variable} php-fpm-service-type
19727 A Service type for @code{php-fpm}.
19730 @deftp {Data Type} php-fpm-configuration
19731 Data Type for php-fpm service configuration.
19733 @item @code{php} (default: @code{php})
19734 The php package to use.
19735 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
19736 The address on which to accept FastCGI requests. Valid syntaxes are:
19738 @item @code{"ip.add.re.ss:port"}
19739 Listen on a TCP socket to a specific address on a specific port.
19740 @item @code{"port"}
19741 Listen on a TCP socket to all addresses on a specific port.
19742 @item @code{"/path/to/unix/socket"}
19743 Listen on a unix socket.
19746 @item @code{user} (default: @code{php-fpm})
19747 User who will own the php worker processes.
19748 @item @code{group} (default: @code{php-fpm})
19749 Group of the worker processes.
19750 @item @code{socket-user} (default: @code{php-fpm})
19751 User who can speak to the php-fpm socket.
19752 @item @code{socket-group} (default: @code{php-fpm})
19753 Group that can speak to the php-fpm socket.
19754 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
19755 The process id of the php-fpm process is written to this file
19756 once the service has started.
19757 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
19758 Log for the php-fpm master process.
19759 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
19760 Detailed settings for the php-fpm process manager.
19763 @item @code{<php-fpm-dynamic-process-manager-configuration>}
19764 @item @code{<php-fpm-static-process-manager-configuration>}
19765 @item @code{<php-fpm-on-demand-process-manager-configuration>}
19767 @item @code{display-errors} (default @code{#f})
19768 Determines whether php errors and warning should be sent to clients
19769 and displayed in their browsers.
19770 This is useful for local php development, but a security risk for public sites,
19771 as error messages can reveal passwords and personal data.
19772 @item @code{timezone} (default @code{#f})
19773 Specifies @code{php_admin_value[date.timezone]} parameter.
19774 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
19775 This file will log the @code{stderr} outputs of php worker processes.
19776 Can be set to @code{#f} to disable logging.
19777 @item @code{file} (default @code{#f})
19778 An optional override of the whole configuration.
19779 You can use the @code{mixed-text-file} function or an absolute filepath for it.
19783 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
19784 Data Type for the @code{dynamic} php-fpm process manager. With the
19785 @code{dynamic} process manager, spare worker processes are kept around
19786 based on it's configured limits.
19788 @item @code{max-children} (default: @code{5})
19789 Maximum of worker processes.
19790 @item @code{start-servers} (default: @code{2})
19791 How many worker processes should be started on start-up.
19792 @item @code{min-spare-servers} (default: @code{1})
19793 How many spare worker processes should be kept around at minimum.
19794 @item @code{max-spare-servers} (default: @code{3})
19795 How many spare worker processes should be kept around at maximum.
19799 @deftp {Data type} php-fpm-static-process-manager-configuration
19800 Data Type for the @code{static} php-fpm process manager. With the
19801 @code{static} process manager, an unchanging number of worker processes
19804 @item @code{max-children} (default: @code{5})
19805 Maximum of worker processes.
19809 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
19810 Data Type for the @code{on-demand} php-fpm process manager. With the
19811 @code{on-demand} process manager, worker processes are only created as
19814 @item @code{max-children} (default: @code{5})
19815 Maximum of worker processes.
19816 @item @code{process-idle-timeout} (default: @code{10})
19817 The time in seconds after which a process with no requests is killed.
19822 @deffn {Scheme Procedure} nginx-php-fpm-location @
19823 [#:nginx-package nginx] @
19824 [socket (string-append "/var/run/php" @
19825 (version-major (package-version php)) @
19827 A helper function to quickly add php to an @code{nginx-server-configuration}.
19830 A simple services setup for nginx with php can look like this:
19832 (services (cons* (service dhcp-client-service-type)
19833 (service php-fpm-service-type)
19834 (service nginx-service-type
19835 (nginx-server-configuration
19836 (server-name '("example.com"))
19837 (root "/srv/http/")
19839 (list (nginx-php-location)))
19841 (ssl-certificate #f)
19842 (ssl-certificate-key #f)))
19846 @cindex cat-avatar-generator
19847 The cat avatar generator is a simple service to demonstrate the use of php-fpm
19848 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
19849 the hash of a user's email address.
19851 @deffn {Scheme Procedure} cat-avatar-generator-service @
19852 [#:cache-dir "/var/cache/cat-avatar-generator"] @
19853 [#:package cat-avatar-generator] @
19854 [#:configuration (nginx-server-configuration)]
19855 Returns an nginx-server-configuration that inherits @code{configuration}. It
19856 extends the nginx configuration to add a server block that serves @code{package},
19857 a version of cat-avatar-generator. During execution, cat-avatar-generator will
19858 be able to use @code{cache-dir} as its cache directory.
19861 A simple setup for cat-avatar-generator can look like this:
19863 (services (cons* (cat-avatar-generator-service
19865 (nginx-server-configuration
19866 (server-name '("example.com"))))
19871 @subsubheading Hpcguix-web
19873 @cindex hpcguix-web
19874 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
19875 program is a customizable web interface to browse Guix packages,
19876 initially designed for users of high-performance computing (HPC)
19879 @defvr {Scheme Variable} hpcguix-web-service-type
19880 The service type for @code{hpcguix-web}.
19883 @deftp {Data Type} hpcguix-web-configuration
19884 Data type for the hpcguix-web service configuration.
19888 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
19889 configuration. The main items available in this spec are:
19892 @item @code{title-prefix} (default: @code{"hpcguix | "})
19893 The page title prefix.
19895 @item @code{guix-command} (default: @code{"guix"})
19896 The @command{guix} command.
19898 @item @code{package-filter-proc} (default: @code{(const #t)})
19899 A procedure specifying how to filter packages that are displayed.
19901 @item @code{package-page-extension-proc} (default: @code{(const '())})
19902 Extension package for @code{hpcguix-web}.
19904 @item @code{menu} (default: @code{'()})
19905 Additional entry in page @code{menu}.
19907 @item @code{channels} (default: @code{%default-channels})
19908 List of channels from which the package list is built (@pxref{Channels}).
19910 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
19911 The expiration time, in seconds, after which the package list is rebuilt from
19912 the latest instances of the given channels.
19915 See the hpcguix-web repository for a
19916 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
19919 @item @code{package} (default: @code{hpcguix-web})
19920 The hpcguix-web package to use.
19924 A typical hpcguix-web service declaration looks like this:
19927 (service hpcguix-web-service-type
19928 (hpcguix-web-configuration
19930 #~(define site-config
19931 (hpcweb-configuration
19932 (title-prefix "Guix-HPC - ")
19933 (menu '(("/about" "ABOUT"))))))))
19937 The hpcguix-web service periodically updates the package list it publishes by
19938 pulling channels from Git. To that end, it needs to access X.509 certificates
19939 so that it can authenticate Git servers when communicating over HTTPS, and it
19940 assumes that @file{/etc/ssl/certs} contains those certificates.
19942 Thus, make sure to add @code{nss-certs} or another certificate package to the
19943 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
19944 more information on X.509 certificates.
19947 @node Certificate Services
19948 @subsection Certificate Services
19951 @cindex HTTP, HTTPS
19952 @cindex Let's Encrypt
19953 @cindex TLS certificates
19954 The @code{(gnu services certbot)} module provides a service to
19955 automatically obtain a valid TLS certificate from the Let's Encrypt
19956 certificate authority. These certificates can then be used to serve
19957 content securely over HTTPS or other TLS-based protocols, with the
19958 knowledge that the client will be able to verify the server's
19961 @url{https://letsencrypt.org/, Let's Encrypt} provides the
19962 @code{certbot} tool to automate the certification process. This tool
19963 first securely generates a key on the server. It then makes a request
19964 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
19965 checks that the request originates from the host in question by using a
19966 challenge-response protocol, requiring the server to provide its
19967 response over HTTP. If that protocol completes successfully, the CA
19968 signs the key, resulting in a certificate. That certificate is valid
19969 for a limited period of time, and therefore to continue to provide TLS
19970 services, the server needs to periodically ask the CA to renew its
19973 The certbot service automates this process: the initial key
19974 generation, the initial certification request to the Let's Encrypt
19975 service, the web server challenge/response integration, writing the
19976 certificate to disk, the automated periodic renewals, and the deployment
19977 tasks associated with the renewal (e.g.@: reloading services, copying keys
19978 with different permissions).
19980 Certbot is run twice a day, at a random minute within the hour. It
19981 won't do anything until your certificates are due for renewal or
19982 revoked, but running it regularly would give your service a chance of
19983 staying online in case a Let's Encrypt-initiated revocation happened for
19986 By using this service, you agree to the ACME Subscriber Agreement, which
19987 can be found there:
19988 @url{https://acme-v01.api.letsencrypt.org/directory}.
19990 @defvr {Scheme Variable} certbot-service-type
19991 A service type for the @code{certbot} Let's Encrypt client. Its value
19992 must be a @code{certbot-configuration} record as in this example:
19995 (define %nginx-deploy-hook
19997 "nginx-deploy-hook"
19998 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
19999 (kill pid SIGHUP))))
20001 (service certbot-service-type
20002 (certbot-configuration
20003 (email "foo@@example.net")
20006 (certificate-configuration
20007 (domains '("example.net" "www.example.net"))
20008 (deploy-hook %nginx-deploy-hook))
20009 (certificate-configuration
20010 (domains '("bar.example.net")))))))
20013 See below for details about @code{certbot-configuration}.
20016 @deftp {Data Type} certbot-configuration
20017 Data type representing the configuration of the @code{certbot} service.
20018 This type has the following parameters:
20021 @item @code{package} (default: @code{certbot})
20022 The certbot package to use.
20024 @item @code{webroot} (default: @code{/var/www})
20025 The directory from which to serve the Let's Encrypt challenge/response
20028 @item @code{certificates} (default: @code{()})
20029 A list of @code{certificates-configuration}s for which to generate
20030 certificates and request signatures. Each certificate has a @code{name}
20031 and several @code{domains}.
20034 Mandatory email used for registration, recovery contact, and important
20035 account notifications.
20037 @item @code{rsa-key-size} (default: @code{2048})
20038 Size of the RSA key.
20040 @item @code{default-location} (default: @i{see below})
20041 The default @code{nginx-location-configuration}. Because @code{certbot}
20042 needs to be able to serve challenges and responses, it needs to be able
20043 to run a web server. It does so by extending the @code{nginx} web
20044 service with an @code{nginx-server-configuration} listening on the
20045 @var{domains} on port 80, and which has a
20046 @code{nginx-location-configuration} for the @code{/.well-known/} URI
20047 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
20048 these nginx configuration data types.
20050 Requests to other URL paths will be matched by the
20051 @code{default-location}, which if present is added to all
20052 @code{nginx-server-configuration}s.
20054 By default, the @code{default-location} will issue a redirect from
20055 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
20056 you to define what to serve on your site via @code{https}.
20058 Pass @code{#f} to not issue a default location.
20062 @deftp {Data Type} certificate-configuration
20063 Data type representing the configuration of a certificate.
20064 This type has the following parameters:
20067 @item @code{name} (default: @i{see below})
20068 This name is used by Certbot for housekeeping and in file paths; it
20069 doesn't affect the content of the certificate itself. To see
20070 certificate names, run @code{certbot certificates}.
20072 Its default is the first provided domain.
20074 @item @code{domains} (default: @code{()})
20075 The first domain provided will be the subject CN of the certificate, and
20076 all domains will be Subject Alternative Names on the certificate.
20078 @item @code{challenge} (default: @code{#f})
20079 The challenge type that has to be run by certbot. If @code{#f} is specified,
20080 default to the HTTP challenge. If a value is specified, defaults to the
20081 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
20082 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}).
20084 @item @code{authentication-hook} (default: @code{#f})
20085 Command to be run in a shell once for each certificate challenge to be
20086 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
20087 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
20088 contains the validation string and @code{$CERTBOT_TOKEN} contains the
20089 file name of the resource requested when performing an HTTP-01 challenge.
20091 @item @code{cleanup-hook} (default: @code{#f})
20092 Command to be run in a shell once for each certificate challenge that
20093 have been answered by the @code{auth-hook}. For this command, the shell
20094 variables available in the @code{auth-hook} script are still available, and
20095 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
20096 of the @code{auth-hook} script.
20098 @item @code{deploy-hook} (default: @code{#f})
20099 Command to be run in a shell once for each successfully issued
20100 certificate. For this command, the shell variable
20101 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
20102 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
20103 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
20104 contain a space-delimited list of renewed certificate domains (for
20105 example, @samp{"example.com www.example.com"}.
20110 For each @code{certificate-configuration}, the certificate is saved to
20111 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
20112 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
20114 @subsection DNS Services
20115 @cindex DNS (domain name system)
20116 @cindex domain name system (DNS)
20118 The @code{(gnu services dns)} module provides services related to the
20119 @dfn{domain name system} (DNS). It provides a server service for hosting
20120 an @emph{authoritative} DNS server for multiple zones, slave or master.
20121 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
20122 caching and forwarding DNS server for the LAN, which uses
20123 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
20125 @subsubheading Knot Service
20127 An example configuration of an authoritative server for two zones, one master
20131 (define-zone-entries example.org.zone
20132 ;; Name TTL Class Type Data
20133 ("@@" "" "IN" "A" "127.0.0.1")
20134 ("@@" "" "IN" "NS" "ns")
20135 ("ns" "" "IN" "A" "127.0.0.1"))
20137 (define master-zone
20138 (knot-zone-configuration
20139 (domain "example.org")
20141 (origin "example.org")
20142 (entries example.org.zone)))))
20145 (knot-zone-configuration
20146 (domain "plop.org")
20147 (dnssec-policy "default")
20148 (master (list "plop-master"))))
20150 (define plop-master
20151 (knot-remote-configuration
20153 (address (list "208.76.58.171"))))
20157 (services (cons* (service knot-service-type
20158 (knot-configuration
20159 (remotes (list plop-master))
20160 (zones (list master-zone slave-zone))))
20165 @deffn {Scheme Variable} knot-service-type
20166 This is the type for the Knot DNS server.
20168 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
20169 zones, that is to say domain names you would buy from a registrar. This server
20170 is not a resolver, meaning that it can only resolve names for which it is
20171 authoritative. This server can be configured to serve zones as a master server
20172 or a slave server as a per-zone basis. Slave zones will get their data from
20173 masters, and will serve it as an authoritative server. From the point of view
20174 of a resolver, there is no difference between master and slave.
20176 The following data types are used to configure the Knot DNS server:
20179 @deftp {Data Type} knot-key-configuration
20180 Data type representing a key.
20181 This type has the following parameters:
20184 @item @code{id} (default: @code{""})
20185 An identifier for other configuration fields to refer to this key. IDs must
20186 be unique and must not be empty.
20188 @item @code{algorithm} (default: @code{#f})
20189 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
20190 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
20191 and @code{'hmac-sha512}.
20193 @item @code{secret} (default: @code{""})
20194 The secret key itself.
20199 @deftp {Data Type} knot-acl-configuration
20200 Data type representing an Access Control List (ACL) configuration.
20201 This type has the following parameters:
20204 @item @code{id} (default: @code{""})
20205 An identifier for ether configuration fields to refer to this key. IDs must be
20206 unique and must not be empty.
20208 @item @code{address} (default: @code{'()})
20209 An ordered list of IP addresses, network subnets, or network ranges represented
20210 with strings. The query must match one of them. Empty value means that
20211 address match is not required.
20213 @item @code{key} (default: @code{'()})
20214 An ordered list of references to keys represented with strings. The string
20215 must match a key ID defined in a @code{knot-key-configuration}. No key means
20216 that a key is not require to match that ACL.
20218 @item @code{action} (default: @code{'()})
20219 An ordered list of actions that are permitted or forbidden by this ACL. Possible
20220 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
20221 and @code{'update}.
20223 @item @code{deny?} (default: @code{#f})
20224 When true, the ACL defines restrictions. Listed actions are forbidden. When
20225 false, listed actions are allowed.
20230 @deftp {Data Type} zone-entry
20231 Data type represnting a record entry in a zone file.
20232 This type has the following parameters:
20235 @item @code{name} (default: @code{"@@"})
20236 The name of the record. @code{"@@"} refers to the origin of the zone. Names
20237 are relative to the origin of the zone. For example, in the @code{example.org}
20238 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
20239 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
20240 refers to @code{ns.example.org}.
20242 @item @code{ttl} (default: @code{""})
20243 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
20245 @item @code{class} (default: @code{"IN"})
20246 The class of the record. Knot currently supports only @code{"IN"} and
20247 partially @code{"CH"}.
20249 @item @code{type} (default: @code{"A"})
20250 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
20251 address), NS (Name Server) and MX (Mail eXchange). Many other types are
20254 @item @code{data} (default: @code{""})
20255 The data contained in the record. For instance an IP address associated with
20256 an A record, or a domain name associated with an NS record. Remember that
20257 domain names are relative to the origin unless they end with a dot.
20262 @deftp {Data Type} zone-file
20263 Data type representing the content of a zone file.
20264 This type has the following parameters:
20267 @item @code{entries} (default: @code{'()})
20268 The list of entries. The SOA record is taken care of, so you don't need to
20269 put it in the list of entries. This list should probably contain an entry
20270 for your primary authoritative DNS server. Other than using a list of entries
20271 directly, you can use @code{define-zone-entries} to define a object containing
20272 the list of entries more easily, that you can later pass to the @code{entries}
20273 field of the @code{zone-file}.
20275 @item @code{origin} (default: @code{""})
20276 The name of your zone. This parameter cannot be empty.
20278 @item @code{ns} (default: @code{"ns"})
20279 The domain of your primary authoritative DNS server. The name is relative to
20280 the origin, unless it ends with a dot. It is mandatory that this primary
20281 DNS server corresponds to an NS record in the zone and that it is associated
20282 to an IP address in the list of entries.
20284 @item @code{mail} (default: @code{"hostmaster"})
20285 An email address people can contact you at, as the owner of the zone. This
20286 is translated as @code{<mail>@@<origin>}.
20288 @item @code{serial} (default: @code{1})
20289 The serial number of the zone. As this is used to keep track of changes by
20290 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
20291 Always increment it when you make a change in your zone.
20293 @item @code{refresh} (default: @code{(* 2 24 3600)})
20294 The frequency at which slaves will do a zone transfer. This value is a number
20295 of seconds. It can be computed by multiplications or with
20296 @code{(string->duration)}.
20298 @item @code{retry} (default: @code{(* 15 60)})
20299 The period after which a slave will retry to contact its master when it fails
20300 to do so a first time.
20302 @item @code{expiry} (default: @code{(* 14 24 3600)})
20303 Default TTL of records. Existing records are considered correct for at most
20304 this amount of time. After this period, resolvers will invalidate their cache
20305 and check again that it still exists.
20307 @item @code{nx} (default: @code{3600})
20308 Default TTL of inexistant records. This delay is usually short because you want
20309 your new domains to reach everyone quickly.
20314 @deftp {Data Type} knot-remote-configuration
20315 Data type representing a remote configuration.
20316 This type has the following parameters:
20319 @item @code{id} (default: @code{""})
20320 An identifier for other configuration fields to refer to this remote. IDs must
20321 be unique and must not be empty.
20323 @item @code{address} (default: @code{'()})
20324 An ordered list of destination IP addresses. Addresses are tried in sequence.
20325 An optional port can be given with the @@ separator. For instance:
20326 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
20328 @item @code{via} (default: @code{'()})
20329 An ordered list of source IP addresses. An empty list will have Knot choose
20330 an appropriate source IP. An optional port can be given with the @@ separator.
20331 The default is to choose at random.
20333 @item @code{key} (default: @code{#f})
20334 A reference to a key, that is a string containing the identifier of a key
20335 defined in a @code{knot-key-configuration} field.
20340 @deftp {Data Type} knot-keystore-configuration
20341 Data type representing a keystore to hold dnssec keys.
20342 This type has the following parameters:
20345 @item @code{id} (default: @code{""})
20346 The id of the keystore. It must not be empty.
20348 @item @code{backend} (default: @code{'pem})
20349 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
20351 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
20352 The configuration string of the backend. An example for the PKCS#11 is:
20353 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
20354 For the pem backend, the string reprensents a path in the file system.
20359 @deftp {Data Type} knot-policy-configuration
20360 Data type representing a dnssec policy. Knot DNS is able to automatically
20361 sign your zones. It can either generate and manage your keys automatically or
20362 use keys that you generate.
20364 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
20365 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
20366 zone. In order to be trusted, the KSK needs to be present in the parent zone
20367 (usually a top-level domain). If your registrar supports dnssec, you will
20368 have to send them your KSK's hash so they can add a DS record in their zone.
20369 This is not automated and need to be done each time you change your KSK.
20371 The policy also defines the lifetime of keys. Usually, ZSK can be changed
20372 easily and use weaker cryptographic functions (they use lower parameters) in
20373 order to sign records quickly, so they are changed often. The KSK however
20374 requires manual interaction with the registrar, so they are changed less often
20375 and use stronger parameters because they sign only one record.
20377 This type has the following parameters:
20380 @item @code{id} (default: @code{""})
20381 The id of the policy. It must not be empty.
20383 @item @code{keystore} (default: @code{"default"})
20384 A reference to a keystore, that is a string containing the identifier of a
20385 keystore defined in a @code{knot-keystore-configuration} field. The
20386 @code{"default"} identifier means the default keystore (a kasp database that
20387 was setup by this service).
20389 @item @code{manual?} (default: @code{#f})
20390 Whether the key management is manual or automatic.
20392 @item @code{single-type-signing?} (default: @code{#f})
20393 When @code{#t}, use the Single-Type Signing Scheme.
20395 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
20396 An algorithm of signing keys and issued signatures.
20398 @item @code{ksk-size} (default: @code{256})
20399 The length of the KSK. Note that this value is correct for the default
20400 algorithm, but would be unsecure for other algorithms.
20402 @item @code{zsk-size} (default: @code{256})
20403 The length of the ZSK. Note that this value is correct for the default
20404 algorithm, but would be unsecure for other algorithms.
20406 @item @code{dnskey-ttl} (default: @code{'default})
20407 The TTL value for DNSKEY records added into zone apex. The special
20408 @code{'default} value means same as the zone SOA TTL.
20410 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
20411 The period between ZSK publication and the next rollover initiation.
20413 @item @code{propagation-delay} (default: @code{(* 24 3600)})
20414 An extra delay added for each key rollover step. This value should be high
20415 enough to cover propagation of data from the master server to all slaves.
20417 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
20418 A validity period of newly issued signatures.
20420 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
20421 A period how long before a signature expiration the signature will be refreshed.
20423 @item @code{nsec3?} (default: @code{#f})
20424 When @code{#t}, NSEC3 will be used instead of NSEC.
20426 @item @code{nsec3-iterations} (default: @code{5})
20427 The number of additional times the hashing is performed.
20429 @item @code{nsec3-salt-length} (default: @code{8})
20430 The length of a salt field in octets, which is appended to the original owner
20431 name before hashing.
20433 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
20434 The validity period of newly issued salt field.
20439 @deftp {Data Type} knot-zone-configuration
20440 Data type representing a zone served by Knot.
20441 This type has the following parameters:
20444 @item @code{domain} (default: @code{""})
20445 The domain served by this configuration. It must not be empty.
20447 @item @code{file} (default: @code{""})
20448 The file where this zone is saved. This parameter is ignored by master zones.
20449 Empty means default location that depends on the domain name.
20451 @item @code{zone} (default: @code{(zone-file)})
20452 The content of the zone file. This parameter is ignored by slave zones. It
20453 must contain a zone-file record.
20455 @item @code{master} (default: @code{'()})
20456 A list of master remotes. When empty, this zone is a master. When set, this
20457 zone is a slave. This is a list of remotes identifiers.
20459 @item @code{ddns-master} (default: @code{#f})
20460 The main master. When empty, it defaults to the first master in the list of
20463 @item @code{notify} (default: @code{'()})
20464 A list of slave remote identifiers.
20466 @item @code{acl} (default: @code{'()})
20467 A list of acl identifiers.
20469 @item @code{semantic-checks?} (default: @code{#f})
20470 When set, this adds more semantic checks to the zone.
20472 @item @code{disable-any?} (default: @code{#f})
20473 When set, this forbids queries of the ANY type.
20475 @item @code{zonefile-sync} (default: @code{0})
20476 The delay between a modification in memory and on disk. 0 means immediate
20479 @item @code{zonefile-load} (default: @code{#f})
20480 The way the zone file contents are applied during zone load. Possible values
20484 @item @code{#f} for using the default value from Knot,
20485 @item @code{'none} for not using the zone file at all,
20486 @item @code{'difference} for computing the difference between already available
20487 contents and zone contents and applying it to the current zone contents,
20488 @item @code{'difference-no-serial} for the same as @code{'difference}, but
20489 ignoring the SOA serial in the zone file, while the server takes care of it
20491 @item @code{'whole} for loading zone contents from the zone file.
20494 @item @code{journal-content} (default: @code{#f})
20495 The way the journal is used to store zone and its changes. Possible values
20496 are @code{'none} to not use it at all, @code{'changes} to store changes and
20497 @code{'all} to store contents. @code{#f} does not set this option, so the
20498 default value from Knot is used.
20500 @item @code{max-journal-usage} (default: @code{#f})
20501 The maximum size for the journal on disk. @code{#f} does not set this option,
20502 so the default value from Knot is used.
20504 @item @code{max-journal-depth} (default: @code{#f})
20505 The maximum size of the history. @code{#f} does not set this option, so the
20506 default value from Knot is used.
20508 @item @code{max-zone-size} (default: @code{#f})
20509 The maximum size of the zone file. This limit is enforced for incoming
20510 transfer and updates. @code{#f} does not set this option, so the default
20511 value from Knot is used.
20513 @item @code{dnssec-policy} (default: @code{#f})
20514 A reference to a @code{knot-policy-configuration} record, or the special
20515 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
20518 @item @code{serial-policy} (default: @code{'increment})
20519 A policy between @code{'increment} and @code{'unixtime}.
20524 @deftp {Data Type} knot-configuration
20525 Data type representing the Knot configuration.
20526 This type has the following parameters:
20529 @item @code{knot} (default: @code{knot})
20532 @item @code{run-directory} (default: @code{"/var/run/knot"})
20533 The run directory. This directory will be used for pid file and sockets.
20535 @item @code{includes} (default: @code{'()})
20536 A list of strings or file-like objects denoting other files that must be
20537 included at the top of the configuration file.
20539 @cindex secrets, Knot service
20540 This can be used to manage secrets out-of-band. For example, secret
20541 keys may be stored in an out-of-band file not managed by Guix, and
20542 thus not visible in @file{/gnu/store}---e.g., you could store secret
20543 key configuration in @file{/etc/knot/secrets.conf} and add this file
20544 to the @code{includes} list.
20546 It can also be used to add configuration not supported by this interface.
20548 @item @code{listen-v4} (default: @code{"0.0.0.0"})
20549 An ip address on which to listen.
20551 @item @code{listen-v6} (default: @code{"::"})
20552 An ip address on which to listen.
20554 @item @code{listen-port} (default: @code{53})
20555 A port on which to listen.
20557 @item @code{keys} (default: @code{'()})
20558 The list of knot-key-configuration used by this configuration.
20560 @item @code{acls} (default: @code{'()})
20561 The list of knot-acl-configuration used by this configuration.
20563 @item @code{remotes} (default: @code{'()})
20564 The list of knot-remote-configuration used by this configuration.
20566 @item @code{zones} (default: @code{'()})
20567 The list of knot-zone-configuration used by this configuration.
20572 @subsubheading Dnsmasq Service
20574 @deffn {Scheme Variable} dnsmasq-service-type
20575 This is the type of the dnsmasq service, whose value should be an
20576 @code{dnsmasq-configuration} object as in this example:
20579 (service dnsmasq-service-type
20580 (dnsmasq-configuration
20582 (servers '("192.168.1.1"))))
20586 @deftp {Data Type} dnsmasq-configuration
20587 Data type representing the configuration of dnsmasq.
20590 @item @code{package} (default: @var{dnsmasq})
20591 Package object of the dnsmasq server.
20593 @item @code{no-hosts?} (default: @code{#f})
20594 When true, don't read the hostnames in /etc/hosts.
20596 @item @code{port} (default: @code{53})
20597 The port to listen on. Setting this to zero completely disables DNS
20598 responses, leaving only DHCP and/or TFTP functions.
20600 @item @code{local-service?} (default: @code{#t})
20601 Accept DNS queries only from hosts whose address is on a local subnet,
20602 ie a subnet for which an interface exists on the server.
20604 @item @code{listen-addresses} (default: @code{'()})
20605 Listen on the given IP addresses.
20607 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
20608 The file to read the IP address of the upstream nameservers from.
20610 @item @code{no-resolv?} (default: @code{#f})
20611 When true, don't read @var{resolv-file}.
20613 @item @code{servers} (default: @code{'()})
20614 Specify IP address of upstream servers directly.
20616 @item @code{cache-size} (default: @code{150})
20617 Set the size of dnsmasq's cache. Setting the cache size to zero
20620 @item @code{negative-cache?} (default: @code{#t})
20621 When false, disable negative caching.
20626 @subsubheading ddclient Service
20629 The ddclient service described below runs the ddclient daemon, which takes
20630 care of automatically updating DNS entries for service providers such as
20631 @uref{https://dyn.com/dns/, Dyn}.
20633 The following example show instantiates the service with its default
20637 (service ddclient-service-type)
20640 Note that ddclient needs to access credentials that are stored in a
20641 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
20642 @code{secret-file} below.) You are expected to create this file manually, in
20643 an ``out-of-band'' fashion (you @emph{could} make this file part of the
20644 service configuration, for instance by using @code{plain-file}, but it will be
20645 world-readable @i{via} @file{/gnu/store}.) See the examples in the
20646 @file{share/ddclient} directory of the @code{ddclient} package.
20648 @c %start of fragment
20650 Available @code{ddclient-configuration} fields are:
20652 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
20653 The ddclient package.
20657 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
20658 The period after which ddclient will retry to check IP and domain name.
20660 Defaults to @samp{300}.
20664 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
20665 Use syslog for the output.
20667 Defaults to @samp{#t}.
20671 @deftypevr {@code{ddclient-configuration} parameter} string mail
20674 Defaults to @samp{"root"}.
20678 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
20679 Mail failed update to user.
20681 Defaults to @samp{"root"}.
20685 @deftypevr {@code{ddclient-configuration} parameter} string pid
20686 The ddclient PID file.
20688 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
20692 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
20693 Enable SSL support.
20695 Defaults to @samp{#t}.
20699 @deftypevr {@code{ddclient-configuration} parameter} string user
20700 Specifies the user name or ID that is used when running ddclient
20703 Defaults to @samp{"ddclient"}.
20707 @deftypevr {@code{ddclient-configuration} parameter} string group
20708 Group of the user who will run the ddclient program.
20710 Defaults to @samp{"ddclient"}.
20714 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
20715 Secret file which will be appended to @file{ddclient.conf} file. This
20716 file contains credentials for use by ddclient. You are expected to
20717 create it manually.
20719 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
20723 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
20724 Extra options will be appended to @file{ddclient.conf} file.
20726 Defaults to @samp{()}.
20731 @c %end of fragment
20735 @subsection VPN Services
20736 @cindex VPN (virtual private network)
20737 @cindex virtual private network (VPN)
20739 The @code{(gnu services vpn)} module provides services related to
20740 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
20741 your machine to connect to a VPN, and a @emph{server} service for your machine
20742 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
20744 @deffn {Scheme Procedure} openvpn-client-service @
20745 [#:config (openvpn-client-configuration)]
20747 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
20750 @deffn {Scheme Procedure} openvpn-server-service @
20751 [#:config (openvpn-server-configuration)]
20753 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
20755 Both can be run simultaneously.
20758 @c %automatically generated documentation
20760 Available @code{openvpn-client-configuration} fields are:
20762 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
20763 The OpenVPN package.
20767 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
20768 The OpenVPN pid file.
20770 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20774 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
20775 The protocol (UDP or TCP) used to open a channel between clients and
20778 Defaults to @samp{udp}.
20782 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
20783 The device type used to represent the VPN connection.
20785 Defaults to @samp{tun}.
20789 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
20790 The certificate authority to check connections against.
20792 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20796 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
20797 The certificate of the machine the daemon is running on. It should be
20798 signed by the authority given in @code{ca}.
20800 Defaults to @samp{"/etc/openvpn/client.crt"}.
20804 @deftypevr {@code{openvpn-client-configuration} parameter} string key
20805 The key of the machine the daemon is running on. It must be the key whose
20806 certificate is @code{cert}.
20808 Defaults to @samp{"/etc/openvpn/client.key"}.
20812 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
20813 Whether to use the lzo compression algorithm.
20815 Defaults to @samp{#t}.
20819 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
20820 Don't re-read key files across SIGUSR1 or --ping-restart.
20822 Defaults to @samp{#t}.
20826 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
20827 Don't close and reopen TUN/TAP device or run up/down scripts across
20828 SIGUSR1 or --ping-restart restarts.
20830 Defaults to @samp{#t}.
20834 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
20837 Defaults to @samp{3}.
20841 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
20842 Add an additional layer of HMAC authentication on top of the TLS control
20843 channel to protect against DoS attacks.
20845 Defaults to @samp{#f}.
20849 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
20850 Whether to check the server certificate has server usage extension.
20852 Defaults to @samp{#t}.
20856 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
20857 Bind to a specific local port number.
20859 Defaults to @samp{#f}.
20863 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
20864 Retry resolving server address.
20866 Defaults to @samp{#t}.
20870 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
20871 A list of remote servers to connect to.
20873 Defaults to @samp{()}.
20875 Available @code{openvpn-remote-configuration} fields are:
20877 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
20880 Defaults to @samp{"my-server"}.
20884 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
20885 Port number the server listens to.
20887 Defaults to @samp{1194}.
20892 @c %end of automatic openvpn-client documentation
20894 @c %automatically generated documentation
20896 Available @code{openvpn-server-configuration} fields are:
20898 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
20899 The OpenVPN package.
20903 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
20904 The OpenVPN pid file.
20906 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20910 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
20911 The protocol (UDP or TCP) used to open a channel between clients and
20914 Defaults to @samp{udp}.
20918 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
20919 The device type used to represent the VPN connection.
20921 Defaults to @samp{tun}.
20925 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
20926 The certificate authority to check connections against.
20928 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20932 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
20933 The certificate of the machine the daemon is running on. It should be
20934 signed by the authority given in @code{ca}.
20936 Defaults to @samp{"/etc/openvpn/client.crt"}.
20940 @deftypevr {@code{openvpn-server-configuration} parameter} string key
20941 The key of the machine the daemon is running on. It must be the key whose
20942 certificate is @code{cert}.
20944 Defaults to @samp{"/etc/openvpn/client.key"}.
20948 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
20949 Whether to use the lzo compression algorithm.
20951 Defaults to @samp{#t}.
20955 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
20956 Don't re-read key files across SIGUSR1 or --ping-restart.
20958 Defaults to @samp{#t}.
20962 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
20963 Don't close and reopen TUN/TAP device or run up/down scripts across
20964 SIGUSR1 or --ping-restart restarts.
20966 Defaults to @samp{#t}.
20970 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
20973 Defaults to @samp{3}.
20977 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
20978 Add an additional layer of HMAC authentication on top of the TLS control
20979 channel to protect against DoS attacks.
20981 Defaults to @samp{#f}.
20985 @deftypevr {@code{openvpn-server-configuration} parameter} number port
20986 Specifies the port number on which the server listens.
20988 Defaults to @samp{1194}.
20992 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
20993 An ip and mask specifying the subnet inside the virtual network.
20995 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
20999 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
21000 A CIDR notation specifying the IPv6 subnet inside the virtual network.
21002 Defaults to @samp{#f}.
21006 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
21007 The Diffie-Hellman parameters file.
21009 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
21013 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
21014 The file that records client IPs.
21016 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
21020 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
21021 When true, the server will act as a gateway for its clients.
21023 Defaults to @samp{#f}.
21027 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
21028 When true, clients are allowed to talk to each other inside the VPN.
21030 Defaults to @samp{#f}.
21034 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
21035 Causes ping-like messages to be sent back and forth over the link so
21036 that each side knows when the other side has gone down. @code{keepalive}
21037 requires a pair. The first element is the period of the ping sending,
21038 and the second element is the timeout before considering the other side
21043 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
21044 The maximum number of clients.
21046 Defaults to @samp{100}.
21050 @deftypevr {@code{openvpn-server-configuration} parameter} string status
21051 The status file. This file shows a small report on current connection.
21052 It is truncated and rewritten every minute.
21054 Defaults to @samp{"/var/run/openvpn/status"}.
21058 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
21059 The list of configuration for some clients.
21061 Defaults to @samp{()}.
21063 Available @code{openvpn-ccd-configuration} fields are:
21065 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
21068 Defaults to @samp{"client"}.
21072 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
21075 Defaults to @samp{#f}.
21079 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
21082 Defaults to @samp{#f}.
21089 @c %end of automatic openvpn-server documentation
21092 @node Network File System
21093 @subsection Network File System
21096 The @code{(gnu services nfs)} module provides the following services,
21097 which are most commonly used in relation to mounting or exporting
21098 directory trees as @dfn{network file systems} (NFS).
21100 @subsubheading RPC Bind Service
21103 The RPC Bind service provides a facility to map program numbers into
21104 universal addresses.
21105 Many NFS related services use this facility. Hence it is automatically
21106 started when a dependent service starts.
21108 @defvr {Scheme Variable} rpcbind-service-type
21109 A service type for the RPC portmapper daemon.
21113 @deftp {Data Type} rpcbind-configuration
21114 Data type representing the configuration of the RPC Bind Service.
21115 This type has the following parameters:
21117 @item @code{rpcbind} (default: @code{rpcbind})
21118 The rpcbind package to use.
21120 @item @code{warm-start?} (default: @code{#t})
21121 If this parameter is @code{#t}, then the daemon will read a
21122 state file on startup thus reloading state information saved by a previous
21128 @subsubheading Pipefs Pseudo File System
21132 The pipefs file system is used to transfer NFS related data
21133 between the kernel and user space programs.
21135 @defvr {Scheme Variable} pipefs-service-type
21136 A service type for the pipefs pseudo file system.
21139 @deftp {Data Type} pipefs-configuration
21140 Data type representing the configuration of the pipefs pseudo file system service.
21141 This type has the following parameters:
21143 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21144 The directory to which the file system is to be attached.
21149 @subsubheading GSS Daemon Service
21152 @cindex global security system
21154 The @dfn{global security system} (GSS) daemon provides strong security for RPC
21156 Before exchanging RPC requests an RPC client must establish a security
21157 context. Typically this is done using the Kerberos command @command{kinit}
21158 or automatically at login time using PAM services (@pxref{Kerberos Services}).
21160 @defvr {Scheme Variable} gss-service-type
21161 A service type for the Global Security System (GSS) daemon.
21164 @deftp {Data Type} gss-configuration
21165 Data type representing the configuration of the GSS daemon service.
21166 This type has the following parameters:
21168 @item @code{nfs-utils} (default: @code{nfs-utils})
21169 The package in which the @command{rpc.gssd} command is to be found.
21171 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21172 The directory where the pipefs file system is mounted.
21178 @subsubheading IDMAP Daemon Service
21180 @cindex name mapper
21182 The idmap daemon service provides mapping between user IDs and user names.
21183 Typically it is required in order to access file systems mounted via NFSv4.
21185 @defvr {Scheme Variable} idmap-service-type
21186 A service type for the Identity Mapper (IDMAP) daemon.
21189 @deftp {Data Type} idmap-configuration
21190 Data type representing the configuration of the IDMAP daemon service.
21191 This type has the following parameters:
21193 @item @code{nfs-utils} (default: @code{nfs-utils})
21194 The package in which the @command{rpc.idmapd} command is to be found.
21196 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21197 The directory where the pipefs file system is mounted.
21199 @item @code{domain} (default: @code{#f})
21200 The local NFSv4 domain name.
21201 This must be a string or @code{#f}.
21202 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
21207 @node Continuous Integration
21208 @subsection Continuous Integration
21210 @cindex continuous integration
21211 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
21212 continuous integration tool for Guix. It can be used both for development and
21213 for providing substitutes to others (@pxref{Substitutes}).
21215 The @code{(gnu services cuirass)} module provides the following service.
21217 @defvr {Scheme Procedure} cuirass-service-type
21218 The type of the Cuirass service. Its value must be a
21219 @code{cuirass-configuration} object, as described below.
21222 To add build jobs, you have to set the @code{specifications} field of the
21223 configuration. Here is an example of a service that polls the Guix repository
21224 and builds the packages from a manifest. Some of the packages are defined in
21225 the @code{"custom-packages"} input, which is the equivalent of
21226 @code{GUIX_PACKAGE_PATH}.
21229 (define %cuirass-specs
21231 '((#:name . "my-manifest")
21232 (#:load-path-inputs . ("guix"))
21233 (#:package-path-inputs . ("custom-packages"))
21234 (#:proc-input . "guix")
21235 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
21236 (#:proc . cuirass-jobs)
21237 (#:proc-args . ((subset . "manifests")
21238 (systems . ("x86_64-linux"))
21239 (manifests . (("config" . "guix/manifest.scm")))))
21240 (#:inputs . (((#:name . "guix")
21241 (#:url . "git://git.savannah.gnu.org/guix.git")
21242 (#:load-path . ".")
21243 (#:branch . "master")
21244 (#:no-compile? . #t))
21245 ((#:name . "config")
21246 (#:url . "git://git.example.org/config.git")
21247 (#:load-path . ".")
21248 (#:branch . "master")
21249 (#:no-compile? . #t))
21250 ((#:name . "custom-packages")
21251 (#:url . "git://git.example.org/custom-packages.git")
21252 (#:load-path . ".")
21253 (#:branch . "master")
21254 (#:no-compile? . #t)))))))
21256 (service cuirass-service-type
21257 (cuirass-configuration
21258 (specifications %cuirass-specs)))
21261 While information related to build jobs is located directly in the
21262 specifications, global settings for the @command{cuirass} process are
21263 accessible in other @code{cuirass-configuration} fields.
21265 @deftp {Data Type} cuirass-configuration
21266 Data type representing the configuration of Cuirass.
21269 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
21270 Location of the log file.
21272 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
21273 Location of the repository cache.
21275 @item @code{user} (default: @code{"cuirass"})
21276 Owner of the @code{cuirass} process.
21278 @item @code{group} (default: @code{"cuirass"})
21279 Owner's group of the @code{cuirass} process.
21281 @item @code{interval} (default: @code{60})
21282 Number of seconds between the poll of the repositories followed by the
21285 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
21286 Location of sqlite database which contains the build results and previously
21287 added specifications.
21289 @item @code{ttl} (default: @code{(* 30 24 3600)})
21290 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
21291 are registered for build results. This means that build results are protected
21292 from garbage collection for at least @var{ttl} seconds.
21294 @item @code{port} (default: @code{8081})
21295 Port number used by the HTTP server.
21297 @item --listen=@var{host}
21298 Listen on the network interface for @var{host}. The default is to
21299 accept connections from localhost.
21301 @item @code{specifications} (default: @code{#~'()})
21302 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
21303 where a specification is an association list
21304 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
21305 keys are keywords (@code{#:keyword-example}) as shown in the example
21308 @item @code{use-substitutes?} (default: @code{#f})
21309 This allows using substitutes to avoid building every dependencies of a job
21312 @item @code{one-shot?} (default: @code{#f})
21313 Only evaluate specifications and build derivations once.
21315 @item @code{fallback?} (default: @code{#f})
21316 When substituting a pre-built binary fails, fall back to building
21319 @item @code{cuirass} (default: @code{cuirass})
21320 The Cuirass package to use.
21324 @node Power Management Services
21325 @subsection Power Management Services
21328 @cindex power management with TLP
21329 @subsubheading TLP daemon
21331 The @code{(gnu services pm)} module provides a Guix service definition
21332 for the Linux power management tool TLP.
21334 TLP enables various powersaving modes in userspace and kernel.
21335 Contrary to @code{upower-service}, it is not a passive,
21336 monitoring tool, as it will apply custom settings each time a new power
21337 source is detected. More information can be found at
21338 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
21340 @deffn {Scheme Variable} tlp-service-type
21341 The service type for the TLP tool. Its value should be a valid
21342 TLP configuration (see below). To use the default settings, simply
21345 (service tlp-service-type)
21349 By default TLP does not need much configuration but most TLP parameters
21350 can be tweaked using @code{tlp-configuration}.
21352 Each parameter definition is preceded by its type; for example,
21353 @samp{boolean foo} indicates that the @code{foo} parameter
21354 should be specified as a boolean. Types starting with
21355 @code{maybe-} denote parameters that won't show up in TLP config file
21356 when their value is @code{'disabled}.
21358 @c The following documentation was initially generated by
21359 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
21360 @c documentation is better, so we shouldn't hesitate to edit below as
21361 @c needed. However if the change you want to make to this documentation
21362 @c can be done in an automated way, it's probably easier to change
21363 @c (generate-documentation) than to make it below and have to deal with
21364 @c the churn as TLP updates.
21366 Available @code{tlp-configuration} fields are:
21368 @deftypevr {@code{tlp-configuration} parameter} package tlp
21373 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
21374 Set to true if you wish to enable TLP.
21376 Defaults to @samp{#t}.
21380 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
21381 Default mode when no power supply can be detected. Alternatives are AC
21384 Defaults to @samp{"AC"}.
21388 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
21389 Number of seconds Linux kernel has to wait after the disk goes idle,
21390 before syncing on AC.
21392 Defaults to @samp{0}.
21396 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
21397 Same as @code{disk-idle-ac} but on BAT mode.
21399 Defaults to @samp{2}.
21403 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
21404 Dirty pages flushing periodicity, expressed in seconds.
21406 Defaults to @samp{15}.
21410 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
21411 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
21413 Defaults to @samp{60}.
21417 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
21418 CPU frequency scaling governor on AC mode. With intel_pstate driver,
21419 alternatives are powersave and performance. With acpi-cpufreq driver,
21420 alternatives are ondemand, powersave, performance and conservative.
21422 Defaults to @samp{disabled}.
21426 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
21427 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
21429 Defaults to @samp{disabled}.
21433 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
21434 Set the min available frequency for the scaling governor on AC.
21436 Defaults to @samp{disabled}.
21440 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
21441 Set the max available frequency for the scaling governor on AC.
21443 Defaults to @samp{disabled}.
21447 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
21448 Set the min available frequency for the scaling governor on BAT.
21450 Defaults to @samp{disabled}.
21454 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
21455 Set the max available frequency for the scaling governor on BAT.
21457 Defaults to @samp{disabled}.
21461 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
21462 Limit the min P-state to control the power dissipation of the CPU, in AC
21463 mode. Values are stated as a percentage of the available performance.
21465 Defaults to @samp{disabled}.
21469 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
21470 Limit the max P-state to control the power dissipation of the CPU, in AC
21471 mode. Values are stated as a percentage of the available performance.
21473 Defaults to @samp{disabled}.
21477 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
21478 Same as @code{cpu-min-perf-on-ac} on BAT mode.
21480 Defaults to @samp{disabled}.
21484 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
21485 Same as @code{cpu-max-perf-on-ac} on BAT mode.
21487 Defaults to @samp{disabled}.
21491 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
21492 Enable CPU turbo boost feature on AC mode.
21494 Defaults to @samp{disabled}.
21498 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
21499 Same as @code{cpu-boost-on-ac?} on BAT mode.
21501 Defaults to @samp{disabled}.
21505 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
21506 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
21507 used under light load conditions.
21509 Defaults to @samp{#f}.
21513 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
21514 Same as @code{sched-powersave-on-ac?} but on BAT mode.
21516 Defaults to @samp{#t}.
21520 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
21521 Enable Linux kernel NMI watchdog.
21523 Defaults to @samp{#f}.
21527 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
21528 For Linux kernels with PHC patch applied, change CPU voltages. An
21529 example value would be @samp{"F:V F:V F:V F:V"}.
21531 Defaults to @samp{disabled}.
21535 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
21536 Set CPU performance versus energy saving policy on AC. Alternatives are
21537 performance, normal, powersave.
21539 Defaults to @samp{"performance"}.
21543 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
21544 Same as @code{energy-perf-policy-ac} but on BAT mode.
21546 Defaults to @samp{"powersave"}.
21550 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
21555 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
21556 Hard disk advanced power management level.
21560 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
21561 Same as @code{disk-apm-bat} but on BAT mode.
21565 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
21566 Hard disk spin down timeout. One value has to be specified for each
21567 declared hard disk.
21569 Defaults to @samp{disabled}.
21573 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
21574 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
21576 Defaults to @samp{disabled}.
21580 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
21581 Select IO scheduler for disk devices. One value has to be specified for
21582 each declared hard disk. Example alternatives are cfq, deadline and
21585 Defaults to @samp{disabled}.
21589 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
21590 SATA aggressive link power management (ALPM) level. Alternatives are
21591 min_power, medium_power, max_performance.
21593 Defaults to @samp{"max_performance"}.
21597 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
21598 Same as @code{sata-linkpwr-ac} but on BAT mode.
21600 Defaults to @samp{"min_power"}.
21604 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
21605 Exclude specified SATA host devices for link power management.
21607 Defaults to @samp{disabled}.
21611 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
21612 Enable Runtime Power Management for AHCI controller and disks on AC
21615 Defaults to @samp{disabled}.
21619 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
21620 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
21622 Defaults to @samp{disabled}.
21626 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
21627 Seconds of inactivity before disk is suspended.
21629 Defaults to @samp{15}.
21633 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
21634 PCI Express Active State Power Management level. Alternatives are
21635 default, performance, powersave.
21637 Defaults to @samp{"performance"}.
21641 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
21642 Same as @code{pcie-aspm-ac} but on BAT mode.
21644 Defaults to @samp{"powersave"}.
21648 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
21649 Radeon graphics clock speed level. Alternatives are low, mid, high,
21652 Defaults to @samp{"high"}.
21656 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
21657 Same as @code{radeon-power-ac} but on BAT mode.
21659 Defaults to @samp{"low"}.
21663 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
21664 Radeon dynamic power management method (DPM). Alternatives are battery,
21667 Defaults to @samp{"performance"}.
21671 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
21672 Same as @code{radeon-dpm-state-ac} but on BAT mode.
21674 Defaults to @samp{"battery"}.
21678 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
21679 Radeon DPM performance level. Alternatives are auto, low, high.
21681 Defaults to @samp{"auto"}.
21685 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
21686 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
21688 Defaults to @samp{"auto"}.
21692 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
21693 Wifi power saving mode.
21695 Defaults to @samp{#f}.
21699 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
21700 Same as @code{wifi-power-ac?} but on BAT mode.
21702 Defaults to @samp{#t}.
21706 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
21707 Disable wake on LAN.
21709 Defaults to @samp{#t}.
21713 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
21714 Timeout duration in seconds before activating audio power saving on
21715 Intel HDA and AC97 devices. A value of 0 disables power saving.
21717 Defaults to @samp{0}.
21721 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
21722 Same as @code{sound-powersave-ac} but on BAT mode.
21724 Defaults to @samp{1}.
21728 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
21729 Disable controller in powersaving mode on Intel HDA devices.
21731 Defaults to @samp{#t}.
21735 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
21736 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
21737 powered on again by releasing (and reinserting) the eject lever or by
21738 pressing the disc eject button on newer models.
21740 Defaults to @samp{#f}.
21744 @deftypevr {@code{tlp-configuration} parameter} string bay-device
21745 Name of the optical drive device to power off.
21747 Defaults to @samp{"sr0"}.
21751 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
21752 Runtime Power Management for PCI(e) bus devices. Alternatives are on
21755 Defaults to @samp{"on"}.
21759 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
21760 Same as @code{runtime-pm-ac} but on BAT mode.
21762 Defaults to @samp{"auto"}.
21766 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
21767 Runtime Power Management for all PCI(e) bus devices, except blacklisted
21770 Defaults to @samp{#t}.
21774 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
21775 Exclude specified PCI(e) device addresses from Runtime Power Management.
21777 Defaults to @samp{disabled}.
21781 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
21782 Exclude PCI(e) devices assigned to the specified drivers from Runtime
21787 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
21788 Enable USB autosuspend feature.
21790 Defaults to @samp{#t}.
21794 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
21795 Exclude specified devices from USB autosuspend.
21797 Defaults to @samp{disabled}.
21801 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
21802 Exclude WWAN devices from USB autosuspend.
21804 Defaults to @samp{#t}.
21808 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
21809 Include specified devices into USB autosuspend, even if they are already
21810 excluded by the driver or via @code{usb-blacklist-wwan?}.
21812 Defaults to @samp{disabled}.
21816 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
21817 Enable USB autosuspend before shutdown.
21819 Defaults to @samp{disabled}.
21823 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
21824 Restore radio device state (bluetooth, wifi, wwan) from previous
21825 shutdown on system startup.
21827 Defaults to @samp{#f}.
21832 @cindex CPU frequency scaling with thermald
21833 @subsubheading Thermald daemon
21835 The @code{(gnu services pm)} module provides an interface to
21836 thermald, a CPU frequency scaling service which helps prevent overheating.
21838 @defvr {Scheme Variable} thermald-service-type
21839 This is the service type for
21840 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
21841 Thermal Daemon, which is responsible for controlling the thermal state
21842 of processors and preventing overheating.
21845 @deftp {Data Type} thermald-configuration
21846 Data type representing the configuration of @code{thermald-service-type}.
21849 @item @code{ignore-cpuid-check?} (default: @code{#f})
21850 Ignore cpuid check for supported CPU models.
21852 @item @code{thermald} (default: @var{thermald})
21853 Package object of thermald.
21858 @node Audio Services
21859 @subsection Audio Services
21861 The @code{(gnu services audio)} module provides a service to start MPD
21862 (the Music Player Daemon).
21865 @subsubheading Music Player Daemon
21867 The Music Player Daemon (MPD) is a service that can play music while
21868 being controlled from the local machine or over the network by a variety
21871 The following example shows how one might run @code{mpd} as user
21872 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
21875 (service mpd-service-type
21881 @defvr {Scheme Variable} mpd-service-type
21882 The service type for @command{mpd}
21885 @deftp {Data Type} mpd-configuration
21886 Data type representing the configuration of @command{mpd}.
21889 @item @code{user} (default: @code{"mpd"})
21890 The user to run mpd as.
21892 @item @code{music-dir} (default: @code{"~/Music"})
21893 The directory to scan for music files.
21895 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
21896 The directory to store playlists.
21898 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
21899 The location of the music database.
21901 @item @code{state-file} (default: @code{"~/.mpd/state"})
21902 The location of the file that stores current MPD's state.
21904 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
21905 The location of the sticker database.
21907 @item @code{port} (default: @code{"6600"})
21908 The port to run mpd on.
21910 @item @code{address} (default: @code{"any"})
21911 The address that mpd will bind to. To use a Unix domain socket,
21912 an absolute path can be specified here.
21917 @node Virtualization Services
21918 @subsection Virtualization services
21920 The @code{(gnu services virtualization)} module provides services for
21921 the libvirt and virtlog daemons, as well as other virtualization-related
21924 @subsubheading Libvirt daemon
21925 @code{libvirtd} is the server side daemon component of the libvirt
21926 virtualization management system. This daemon runs on host servers
21927 and performs required management tasks for virtualized guests.
21929 @deffn {Scheme Variable} libvirt-service-type
21930 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
21931 Its value must be a @code{libvirt-configuration}.
21934 (service libvirt-service-type
21935 (libvirt-configuration
21936 (unix-sock-group "libvirt")
21937 (tls-port "16555")))
21941 @c Auto-generated with (generate-libvirt-documentation)
21942 Available @code{libvirt-configuration} fields are:
21944 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
21949 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
21950 Flag listening for secure TLS connections on the public TCP/IP port.
21951 must set @code{listen} for this to have any effect.
21953 It is necessary to setup a CA and issue server certificates before using
21956 Defaults to @samp{#t}.
21960 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
21961 Listen for unencrypted TCP connections on the public TCP/IP port. must
21962 set @code{listen} for this to have any effect.
21964 Using the TCP socket requires SASL authentication by default. Only SASL
21965 mechanisms which support data encryption are allowed. This is
21966 DIGEST_MD5 and GSSAPI (Kerberos5)
21968 Defaults to @samp{#f}.
21972 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
21973 Port for accepting secure TLS connections This can be a port number, or
21976 Defaults to @samp{"16514"}.
21980 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
21981 Port for accepting insecure TCP connections This can be a port number,
21984 Defaults to @samp{"16509"}.
21988 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
21989 IP address or hostname used for client connections.
21991 Defaults to @samp{"0.0.0.0"}.
21995 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
21996 Flag toggling mDNS advertisement of the libvirt service.
21998 Alternatively can disable for all services on a host by stopping the
22001 Defaults to @samp{#f}.
22005 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
22006 Default mDNS advertisement name. This must be unique on the immediate
22009 Defaults to @samp{"Virtualization Host <hostname>"}.
22013 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
22014 UNIX domain socket group ownership. This can be used to allow a
22015 'trusted' set of users access to management capabilities without
22018 Defaults to @samp{"root"}.
22022 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
22023 UNIX socket permissions for the R/O socket. This is used for monitoring
22026 Defaults to @samp{"0777"}.
22030 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
22031 UNIX socket permissions for the R/W socket. Default allows only root.
22032 If PolicyKit is enabled on the socket, the default will change to allow
22033 everyone (eg, 0777)
22035 Defaults to @samp{"0770"}.
22039 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
22040 UNIX socket permissions for the admin socket. Default allows only owner
22041 (root), do not change it unless you are sure to whom you are exposing
22044 Defaults to @samp{"0777"}.
22048 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
22049 The directory in which sockets will be found/created.
22051 Defaults to @samp{"/var/run/libvirt"}.
22055 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
22056 Authentication scheme for UNIX read-only sockets. By default socket
22057 permissions allow anyone to connect
22059 Defaults to @samp{"polkit"}.
22063 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
22064 Authentication scheme for UNIX read-write sockets. By default socket
22065 permissions only allow root. If PolicyKit support was compiled into
22066 libvirt, the default will be to use 'polkit' auth.
22068 Defaults to @samp{"polkit"}.
22072 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
22073 Authentication scheme for TCP sockets. If you don't enable SASL, then
22074 all TCP traffic is cleartext. Don't do this outside of a dev/test
22077 Defaults to @samp{"sasl"}.
22081 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
22082 Authentication scheme for TLS sockets. TLS sockets already have
22083 encryption provided by the TLS layer, and limited authentication is done
22086 It is possible to make use of any SASL authentication mechanism as well,
22087 by using 'sasl' for this option
22089 Defaults to @samp{"none"}.
22093 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
22094 API access control scheme.
22096 By default an authenticated user is allowed access to all APIs. Access
22097 drivers can place restrictions on this.
22099 Defaults to @samp{()}.
22103 @deftypevr {@code{libvirt-configuration} parameter} string key-file
22104 Server key file path. If set to an empty string, then no private key is
22107 Defaults to @samp{""}.
22111 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
22112 Server key file path. If set to an empty string, then no certificate is
22115 Defaults to @samp{""}.
22119 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
22120 Server key file path. If set to an empty string, then no CA certificate
22123 Defaults to @samp{""}.
22127 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
22128 Certificate revocation list path. If set to an empty string, then no
22131 Defaults to @samp{""}.
22135 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
22136 Disable verification of our own server certificates.
22138 When libvirtd starts it performs some sanity checks against its own
22141 Defaults to @samp{#f}.
22145 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
22146 Disable verification of client certificates.
22148 Client certificate verification is the primary authentication mechanism.
22149 Any client which does not present a certificate signed by the CA will be
22152 Defaults to @samp{#f}.
22156 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
22157 Whitelist of allowed x509 Distinguished Name.
22159 Defaults to @samp{()}.
22163 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
22164 Whitelist of allowed SASL usernames. The format for username depends on
22165 the SASL authentication mechanism.
22167 Defaults to @samp{()}.
22171 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
22172 Override the compile time default TLS priority string. The default is
22173 usually "NORMAL" unless overridden at build time. Only set this is it
22174 is desired for libvirt to deviate from the global default settings.
22176 Defaults to @samp{"NORMAL"}.
22180 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
22181 Maximum number of concurrent client connections to allow over all
22184 Defaults to @samp{5000}.
22188 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
22189 Maximum length of queue of connections waiting to be accepted by the
22190 daemon. Note, that some protocols supporting retransmission may obey
22191 this so that a later reattempt at connection succeeds.
22193 Defaults to @samp{1000}.
22197 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
22198 Maximum length of queue of accepted but not yet authenticated clients.
22199 Set this to zero to turn this feature off
22201 Defaults to @samp{20}.
22205 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
22206 Number of workers to start up initially.
22208 Defaults to @samp{5}.
22212 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
22213 Maximum number of worker threads.
22215 If the number of active clients exceeds @code{min-workers}, then more
22216 threads are spawned, up to max_workers limit. Typically you'd want
22217 max_workers to equal maximum number of clients allowed.
22219 Defaults to @samp{20}.
22223 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
22224 Number of priority workers. If all workers from above pool are stuck,
22225 some calls marked as high priority (notably domainDestroy) can be
22226 executed in this pool.
22228 Defaults to @samp{5}.
22232 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
22233 Total global limit on concurrent RPC calls.
22235 Defaults to @samp{20}.
22239 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
22240 Limit on concurrent requests from a single client connection. To avoid
22241 one client monopolizing the server this should be a small fraction of
22242 the global max_requests and max_workers parameter.
22244 Defaults to @samp{5}.
22248 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
22249 Same as @code{min-workers} but for the admin interface.
22251 Defaults to @samp{1}.
22255 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
22256 Same as @code{max-workers} but for the admin interface.
22258 Defaults to @samp{5}.
22262 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
22263 Same as @code{max-clients} but for the admin interface.
22265 Defaults to @samp{5}.
22269 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
22270 Same as @code{max-queued-clients} but for the admin interface.
22272 Defaults to @samp{5}.
22276 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
22277 Same as @code{max-client-requests} but for the admin interface.
22279 Defaults to @samp{5}.
22283 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
22284 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
22286 Defaults to @samp{3}.
22290 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
22293 A filter allows to select a different logging level for a given category
22294 of logs The format for a filter is one of:
22305 where @code{name} is a string which is matched against the category
22306 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
22307 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
22308 be a substring of the full category name, in order to match multiple
22309 similar categories), the optional "+" prefix tells libvirt to log stack
22310 trace for each message matching name, and @code{x} is the minimal level
22311 where matching messages should be logged:
22328 Multiple filters can be defined in a single filters statement, they just
22329 need to be separated by spaces.
22331 Defaults to @samp{"3:remote 4:event"}.
22335 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
22338 An output is one of the places to save logging information. The format
22339 for an output can be:
22343 output goes to stderr
22345 @item x:syslog:name
22346 use syslog for the output and use the given name as the ident
22348 @item x:file:file_path
22349 output to a file, with the given filepath
22352 output to journald logging system
22356 In all case the x prefix is the minimal level, acting as a filter
22373 Multiple outputs can be defined, they just need to be separated by
22376 Defaults to @samp{"3:stderr"}.
22380 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
22381 Allows usage of the auditing subsystem to be altered
22385 0: disable all auditing
22388 1: enable auditing, only if enabled on host
22391 2: enable auditing, and exit if disabled on host.
22395 Defaults to @samp{1}.
22399 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
22400 Send audit messages via libvirt logging infrastructure.
22402 Defaults to @samp{#f}.
22406 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
22407 Host UUID. UUID must not have all digits be the same.
22409 Defaults to @samp{""}.
22413 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
22414 Source to read host UUID.
22418 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
22421 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
22425 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
22428 Defaults to @samp{"smbios"}.
22432 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
22433 A keepalive message is sent to a client after @code{keepalive_interval}
22434 seconds of inactivity to check if the client is still responding. If
22435 set to -1, libvirtd will never send keepalive requests; however clients
22436 can still send them and the daemon will send responses.
22438 Defaults to @samp{5}.
22442 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
22443 Maximum number of keepalive messages that are allowed to be sent to the
22444 client without getting any response before the connection is considered
22447 In other words, the connection is automatically closed approximately
22448 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
22449 the last message received from the client. When @code{keepalive-count}
22450 is set to 0, connections will be automatically closed after
22451 @code{keepalive-interval} seconds of inactivity without sending any
22452 keepalive messages.
22454 Defaults to @samp{5}.
22458 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
22459 Same as above but for admin interface.
22461 Defaults to @samp{5}.
22465 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
22466 Same as above but for admin interface.
22468 Defaults to @samp{5}.
22472 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
22473 Timeout for Open vSwitch calls.
22475 The @code{ovs-vsctl} utility is used for the configuration and its
22476 timeout option is set by default to 5 seconds to avoid potential
22477 infinite waits blocking libvirt.
22479 Defaults to @samp{5}.
22483 @c %end of autogenerated docs
22485 @subsubheading Virtlog daemon
22486 The virtlogd service is a server side daemon component of libvirt that is
22487 used to manage logs from virtual machine consoles.
22489 This daemon is not used directly by libvirt client applications, rather it
22490 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
22491 standalone daemon, the main @code{libvirtd} daemon can be restarted without
22492 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
22493 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
22495 @deffn {Scheme Variable} virtlog-service-type
22496 This is the type of the virtlog daemon.
22497 Its value must be a @code{virtlog-configuration}.
22500 (service virtlog-service-type
22501 (virtlog-configuration
22502 (max-clients 1000)))
22506 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
22507 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
22509 Defaults to @samp{3}.
22513 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
22516 A filter allows to select a different logging level for a given category
22517 of logs The format for a filter is one of:
22528 where @code{name} is a string which is matched against the category
22529 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
22530 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
22531 be a substring of the full category name, in order to match multiple
22532 similar categories), the optional "+" prefix tells libvirt to log stack
22533 trace for each message matching name, and @code{x} is the minimal level
22534 where matching messages should be logged:
22551 Multiple filters can be defined in a single filters statement, they just
22552 need to be separated by spaces.
22554 Defaults to @samp{"3:remote 4:event"}.
22558 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
22561 An output is one of the places to save logging information The format
22562 for an output can be:
22566 output goes to stderr
22568 @item x:syslog:name
22569 use syslog for the output and use the given name as the ident
22571 @item x:file:file_path
22572 output to a file, with the given filepath
22575 output to journald logging system
22579 In all case the x prefix is the minimal level, acting as a filter
22596 Multiple outputs can be defined, they just need to be separated by
22599 Defaults to @samp{"3:stderr"}.
22603 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
22604 Maximum number of concurrent client connections to allow over all
22607 Defaults to @samp{1024}.
22611 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
22612 Maximum file size before rolling over.
22614 Defaults to @samp{2MB}
22618 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
22619 Maximum number of backup files to keep.
22621 Defaults to @samp{3}
22625 @subsubheading Transparent Emulation with QEMU
22628 @cindex @code{binfmt_misc}
22629 @code{qemu-binfmt-service-type} provides support for transparent
22630 emulation of program binaries built for different architectures---e.g.,
22631 it allows you to transparently execute an ARMv7 program on an x86_64
22632 machine. It achieves this by combining the @uref{https://www.qemu.org,
22633 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
22635 @defvr {Scheme Variable} qemu-binfmt-service-type
22636 This is the type of the QEMU/binfmt service for transparent emulation.
22637 Its value must be a @code{qemu-binfmt-configuration} object, which
22638 specifies the QEMU package to use as well as the architecture we want to
22642 (service qemu-binfmt-service-type
22643 (qemu-binfmt-configuration
22644 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
22647 In this example, we enable transparent emulation for the ARM and aarch64
22648 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
22649 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
22650 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
22653 @deftp {Data Type} qemu-binfmt-configuration
22654 This is the configuration for the @code{qemu-binfmt} service.
22657 @item @code{platforms} (default: @code{'()})
22658 The list of emulated QEMU platforms. Each item must be a @dfn{platform
22659 object} as returned by @code{lookup-qemu-platforms} (see below).
22661 @item @code{guix-support?} (default: @code{#f})
22662 When it is true, QEMU and all its dependencies are added to the build
22663 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
22664 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
22665 handlers to be used within the build environment, which in turn means
22666 that you can transparently build programs for another architecture.
22668 For example, let's suppose you're on an x86_64 machine and you have this
22672 (service qemu-binfmt-service-type
22673 (qemu-binfmt-configuration
22674 (platforms (lookup-qemu-platforms "arm"))
22675 (guix-support? #t)))
22681 guix build -s armhf-linux inkscape
22685 and it will build Inkscape for ARMv7 @emph{as if it were a native
22686 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
22687 if you'd like to test a package build for an architecture you don't have
22690 @item @code{qemu} (default: @code{qemu})
22691 The QEMU package to use.
22695 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
22696 Return the list of QEMU platform objects corresponding to
22697 @var{platforms}@dots{}. @var{platforms} must be a list of strings
22698 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
22699 @code{"mips64el"}, and so on.
22702 @deffn {Scheme Procedure} qemu-platform? @var{obj}
22703 Return true if @var{obj} is a platform object.
22706 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
22707 Return the name of @var{platform}---a string such as @code{"arm"}.
22710 @node Version Control Services
22711 @subsection Version Control Services
22713 The @code{(gnu services version-control)} module provides a service to
22714 allow remote access to local Git repositories. There are three options:
22715 the @code{git-daemon-service}, which provides access to repositories via
22716 the @code{git://} unsecured TCP-based protocol, extending the
22717 @code{nginx} web server to proxy some requests to
22718 @code{git-http-backend}, or providing a web interface with
22719 @code{cgit-service-type}.
22721 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
22723 Return a service that runs @command{git daemon}, a simple TCP server to
22724 expose repositories over the Git protocol for anonymous access.
22726 The optional @var{config} argument should be a
22727 @code{<git-daemon-configuration>} object, by default it allows read-only
22728 access to exported@footnote{By creating the magic file
22729 "git-daemon-export-ok" in the repository directory.} repositories under
22734 @deftp {Data Type} git-daemon-configuration
22735 Data type representing the configuration for @code{git-daemon-service}.
22738 @item @code{package} (default: @var{git})
22739 Package object of the Git distributed version control system.
22741 @item @code{export-all?} (default: @var{#f})
22742 Whether to allow access for all Git repositories, even if they do not
22743 have the @file{git-daemon-export-ok} file.
22745 @item @code{base-path} (default: @file{/srv/git})
22746 Whether to remap all the path requests as relative to the given path.
22747 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
22748 then if you later try to pull @code{git://example.com/hello.git}, git
22749 daemon will interpret the path as @code{/srv/git/hello.git}.
22751 @item @code{user-path} (default: @var{#f})
22752 Whether to allow @code{~user} notation to be used in requests. When
22753 specified with empty string, requests to @code{git://host/~alice/foo} is
22754 taken as a request to access @code{foo} repository in the home directory
22755 of user @code{alice}. If @var{(user-path "path")} is specified, the
22756 same request is taken as a request to access @code{path/foo} repository
22757 in the home directory of user @code{alice}.
22759 @item @code{listen} (default: @var{'()})
22760 Whether to listen on specific IP addresses or hostnames, defaults to
22763 @item @code{port} (default: @var{#f})
22764 Whether to listen on an alternative port, which defaults to 9418.
22766 @item @code{whitelist} (default: @var{'()})
22767 If not empty, only allow access to this list of directories.
22769 @item @code{extra-options} (default: @var{'()})
22770 Extra options will be passed to @code{git daemon}, please run
22771 @command{man git-daemon} for more information.
22776 The @code{git://} protocol lacks authentication. When you pull from a
22777 repository fetched via @code{git://}, you don't know whether the data you
22778 receive was modified or is even coming from the specified host, and your
22779 connection is subject to eavesdropping. It's better to use an authenticated
22780 and encrypted transport, such as @code{https}. Although Git allows you
22781 to serve repositories using unsophisticated file-based web servers,
22782 there is a faster protocol implemented by the @code{git-http-backend}
22783 program. This program is the back-end of a proper Git web service. It
22784 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
22785 on running the necessary @code{fcgiwrap} daemon.
22787 Guix has a separate configuration data type for serving Git repositories
22790 @deftp {Data Type} git-http-configuration
22791 Data type representing the configuration for @code{git-http-service}.
22794 @item @code{package} (default: @var{git})
22795 Package object of the Git distributed version control system.
22797 @item @code{git-root} (default: @file{/srv/git})
22798 Directory containing the Git repositories to expose to the world.
22800 @item @code{export-all?} (default: @var{#f})
22801 Whether to expose access for all Git repositories in @var{git-root},
22802 even if they do not have the @file{git-daemon-export-ok} file.
22804 @item @code{uri-path} (default: @file{/git/})
22805 Path prefix for Git access. With the default @code{/git/} prefix, this
22806 will map @code{http://@var{server}/git/@var{repo}.git} to
22807 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
22808 with this prefix are not passed on to this Git instance.
22810 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
22811 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
22816 There is no @code{git-http-service-type}, currently; instead you can
22817 create an @code{nginx-location-configuration} from a
22818 @code{git-http-configuration} and then add that location to a web
22821 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
22822 [config=(git-http-configuration)]
22823 Compute an @code{nginx-location-configuration} that corresponds to the
22824 given Git http configuration. An example nginx service definition to
22825 serve the default @file{/srv/git} over HTTPS might be:
22828 (service nginx-service-type
22829 (nginx-configuration
22832 (nginx-server-configuration
22833 (listen '("443 ssl"))
22834 (server-name "git.my-host.org")
22836 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
22837 (ssl-certificate-key
22838 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
22841 (git-http-nginx-location-configuration
22842 (git-http-configuration (uri-path "/"))))))))))
22845 This example assumes that you are using Let's Encrypt to get your TLS
22846 certificate. @xref{Certificate Services}. The default @code{certbot}
22847 service will redirect all HTTP traffic on @code{git.my-host.org} to
22848 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
22849 system services. @xref{Web Services}.
22852 @subsubheading Cgit Service
22854 @cindex Cgit service
22855 @cindex Git, web interface
22856 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
22857 repositories written in C.
22859 The following example will configure the service with default values.
22860 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
22863 (service cgit-service-type)
22866 The @code{file-object} type designates either a file-like object
22867 (@pxref{G-Expressions, file-like objects}) or a string.
22869 @c %start of fragment
22871 Available @code{cgit-configuration} fields are:
22873 @deftypevr {@code{cgit-configuration} parameter} package package
22878 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
22879 NGINX configuration.
22883 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
22884 Specifies a command which will be invoked to format the content of about
22885 pages (both top-level and for each repository).
22887 Defaults to @samp{""}.
22891 @deftypevr {@code{cgit-configuration} parameter} string agefile
22892 Specifies a path, relative to each repository path, which can be used to
22893 specify the date and time of the youngest commit in the repository.
22895 Defaults to @samp{""}.
22899 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
22900 Specifies a command that will be invoked for authenticating repository
22903 Defaults to @samp{""}.
22907 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
22908 Flag which, when set to @samp{age}, enables date ordering in the branch
22909 ref list, and when set @samp{name} enables ordering by branch name.
22911 Defaults to @samp{"name"}.
22915 @deftypevr {@code{cgit-configuration} parameter} string cache-root
22916 Path used to store the cgit cache entries.
22918 Defaults to @samp{"/var/cache/cgit"}.
22922 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
22923 Number which specifies the time-to-live, in minutes, for the cached
22924 version of repository pages accessed with a fixed SHA1.
22926 Defaults to @samp{-1}.
22930 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
22931 Number which specifies the time-to-live, in minutes, for the cached
22932 version of repository pages accessed without a fixed SHA1.
22934 Defaults to @samp{5}.
22938 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
22939 Number which specifies the time-to-live, in minutes, for the cached
22940 version of the repository summary page.
22942 Defaults to @samp{5}.
22946 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
22947 Number which specifies the time-to-live, in minutes, for the cached
22948 version of the repository index page.
22950 Defaults to @samp{5}.
22954 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
22955 Number which specifies the time-to-live, in minutes, for the result of
22956 scanning a path for Git repositories.
22958 Defaults to @samp{15}.
22962 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
22963 Number which specifies the time-to-live, in minutes, for the cached
22964 version of the repository about page.
22966 Defaults to @samp{15}.
22970 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
22971 Number which specifies the time-to-live, in minutes, for the cached
22972 version of snapshots.
22974 Defaults to @samp{5}.
22978 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
22979 The maximum number of entries in the cgit cache. When set to @samp{0},
22980 caching is disabled.
22982 Defaults to @samp{0}.
22986 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
22987 Sort items in the repo list case sensitively.
22989 Defaults to @samp{#t}.
22993 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
22994 List of common prefixes which, when combined with a repository URL,
22995 generates valid clone URLs for the repository.
22997 Defaults to @samp{()}.
23001 @deftypevr {@code{cgit-configuration} parameter} list clone-url
23002 List of @code{clone-url} templates.
23004 Defaults to @samp{()}.
23008 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
23009 Command which will be invoked to format commit messages.
23011 Defaults to @samp{""}.
23015 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
23016 Flag which, when set to @samp{date}, enables strict date ordering in the
23017 commit log, and when set to @samp{topo} enables strict topological
23020 Defaults to @samp{"git log"}.
23024 @deftypevr {@code{cgit-configuration} parameter} file-object css
23025 URL which specifies the css document to include in all cgit pages.
23027 Defaults to @samp{"/share/cgit/cgit.css"}.
23031 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
23032 Specifies a command which will be invoked to format names and email
23033 address of committers, authors, and taggers, as represented in various
23034 places throughout the cgit interface.
23036 Defaults to @samp{""}.
23040 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
23041 Flag which, when set to @samp{#t}, will make cgit generate a HTML
23042 fragment suitable for embedding in other HTML pages.
23044 Defaults to @samp{#f}.
23048 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
23049 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
23050 commit history graph to the left of the commit messages in the
23051 repository log page.
23053 Defaults to @samp{#f}.
23057 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
23058 Flag which, when set to @samp{#t}, allows all filter settings to be
23059 overridden in repository-specific cgitrc files.
23061 Defaults to @samp{#f}.
23065 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
23066 Flag which, when set to @samp{#t}, allows users to follow a file in the
23069 Defaults to @samp{#f}.
23073 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
23074 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
23077 Defaults to @samp{#t}.
23081 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
23082 Flag which, when set to @samp{#t}, will make cgit generate extra links
23083 "summary", "commit", "tree" for each repo in the repository index.
23085 Defaults to @samp{#f}.
23089 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
23090 Flag which, when set to @samp{#t}, will make cgit display the owner of
23091 each repo in the repository index.
23093 Defaults to @samp{#t}.
23097 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
23098 Flag which, when set to @samp{#t}, will make cgit print the number of
23099 modified files for each commit on the repository log page.
23101 Defaults to @samp{#f}.
23105 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
23106 Flag which, when set to @samp{#t}, will make cgit print the number of
23107 added and removed lines for each commit on the repository log page.
23109 Defaults to @samp{#f}.
23113 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
23114 Flag which, when set to @code{#t}, will make cgit display remote
23115 branches in the summary and refs views.
23117 Defaults to @samp{#f}.
23121 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
23122 Flag which, when set to @code{1}, will make cgit use the subject of the
23123 parent commit as link text when generating links to parent commits in
23126 Defaults to @samp{#f}.
23130 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
23131 Flag which, when set to @samp{#t}, will make cgit use the subject of the
23132 parent commit as link text when generating links to parent commits in
23135 Defaults to @samp{#f}.
23139 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
23140 Flag which, when set to @samp{#t}, will make cgit generate linenumber
23141 links for plaintext blobs printed in the tree view.
23143 Defaults to @samp{#t}.
23147 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
23148 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
23149 set any repo specific settings.
23151 Defaults to @samp{#f}.
23155 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
23156 URL used as link to a shortcut icon for cgit.
23158 Defaults to @samp{"/favicon.ico"}.
23162 @deftypevr {@code{cgit-configuration} parameter} string footer
23163 The content of the file specified with this option will be included
23164 verbatim at the bottom of all pages (i.e.@: it replaces the standard
23165 "generated by..."@: message).
23167 Defaults to @samp{""}.
23171 @deftypevr {@code{cgit-configuration} parameter} string head-include
23172 The content of the file specified with this option will be included
23173 verbatim in the HTML HEAD section on all pages.
23175 Defaults to @samp{""}.
23179 @deftypevr {@code{cgit-configuration} parameter} string header
23180 The content of the file specified with this option will be included
23181 verbatim at the top of all pages.
23183 Defaults to @samp{""}.
23187 @deftypevr {@code{cgit-configuration} parameter} file-object include
23188 Name of a configfile to include before the rest of the current config-
23191 Defaults to @samp{""}.
23195 @deftypevr {@code{cgit-configuration} parameter} string index-header
23196 The content of the file specified with this option will be included
23197 verbatim above the repository index.
23199 Defaults to @samp{""}.
23203 @deftypevr {@code{cgit-configuration} parameter} string index-info
23204 The content of the file specified with this option will be included
23205 verbatim below the heading on the repository index page.
23207 Defaults to @samp{""}.
23211 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
23212 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
23213 in the servers timezone.
23215 Defaults to @samp{#f}.
23219 @deftypevr {@code{cgit-configuration} parameter} file-object logo
23220 URL which specifies the source of an image which will be used as a logo
23223 Defaults to @samp{"/share/cgit/cgit.png"}.
23227 @deftypevr {@code{cgit-configuration} parameter} string logo-link
23228 URL loaded when clicking on the cgit logo image.
23230 Defaults to @samp{""}.
23234 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
23235 Command which will be invoked to format the Owner column of the main
23238 Defaults to @samp{""}.
23242 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
23243 Number of items to display in atom feeds view.
23245 Defaults to @samp{10}.
23249 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
23250 Number of entries to list per page in "log" view.
23252 Defaults to @samp{50}.
23256 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
23257 Number of commit message characters to display in "log" view.
23259 Defaults to @samp{80}.
23263 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
23264 Specifies the number of entries to list per page on the repository index
23267 Defaults to @samp{50}.
23271 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
23272 Specifies the maximum number of repo description characters to display
23273 on the repository index page.
23275 Defaults to @samp{80}.
23279 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
23280 Specifies the maximum size of a blob to display HTML for in KBytes.
23282 Defaults to @samp{0}.
23286 @deftypevr {@code{cgit-configuration} parameter} string max-stats
23287 Maximum statistics period. Valid values are @samp{week},@samp{month},
23288 @samp{quarter} and @samp{year}.
23290 Defaults to @samp{""}.
23294 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
23295 Mimetype for the specified filename extension.
23297 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
23298 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
23299 "image/png") (svg "image/svg+xml"))}.
23303 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
23304 Specifies the file to use for automatic mimetype lookup.
23306 Defaults to @samp{""}.
23310 @deftypevr {@code{cgit-configuration} parameter} string module-link
23311 Text which will be used as the formatstring for a hyperlink when a
23312 submodule is printed in a directory listing.
23314 Defaults to @samp{""}.
23318 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
23319 If set to the value @samp{#t} caching will be disabled.
23321 Defaults to @samp{#f}.
23325 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
23326 If set to @samp{#t} showing full author email addresses will be
23329 Defaults to @samp{#f}.
23333 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
23334 Flag which, when set to @samp{#t}, will make cgit omit the standard
23335 header on all pages.
23337 Defaults to @samp{#f}.
23341 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
23342 A list of subdirectories inside of @code{repository-directory}, relative
23343 to it, that should loaded as Git repositories. An empty list means that
23344 all subdirectories will be loaded.
23346 Defaults to @samp{()}.
23350 @deftypevr {@code{cgit-configuration} parameter} file-object readme
23351 Text which will be used as default value for @code{cgit-repo-readme}.
23353 Defaults to @samp{""}.
23357 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
23358 If set to @code{#t} and @code{repository-directory} is enabled, if any
23359 repositories are found with a suffix of @code{.git}, this suffix will be
23360 removed for the URL and name.
23362 Defaults to @samp{#f}.
23366 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
23367 Maximum number of files to consider when detecting renames.
23369 Defaults to @samp{-1}.
23373 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
23374 The way in which repositories in each section are sorted.
23376 Defaults to @samp{""}.
23380 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
23381 Text used as content for the @code{robots} meta-tag.
23383 Defaults to @samp{("noindex" "nofollow")}.
23387 @deftypevr {@code{cgit-configuration} parameter} string root-desc
23388 Text printed below the heading on the repository index page.
23390 Defaults to @samp{"a fast webinterface for the git dscm"}.
23394 @deftypevr {@code{cgit-configuration} parameter} string root-readme
23395 The content of the file specified with this option will be included
23396 verbatim below thef "about" link on the repository index page.
23398 Defaults to @samp{""}.
23402 @deftypevr {@code{cgit-configuration} parameter} string root-title
23403 Text printed as heading on the repository index page.
23405 Defaults to @samp{""}.
23409 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
23410 If set to @samp{#t} and repository-directory is enabled,
23411 repository-directory will recurse into directories whose name starts
23412 with a period. Otherwise, repository-directory will stay away from such
23413 directories, considered as "hidden". Note that this does not apply to
23414 the ".git" directory in non-bare repos.
23416 Defaults to @samp{#f}.
23420 @deftypevr {@code{cgit-configuration} parameter} list snapshots
23421 Text which specifies the default set of snapshot formats that cgit
23422 generates links for.
23424 Defaults to @samp{()}.
23428 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
23429 Name of the directory to scan for repositories (represents
23432 Defaults to @samp{"/srv/git"}.
23436 @deftypevr {@code{cgit-configuration} parameter} string section
23437 The name of the current repository section - all repositories defined
23438 after this option will inherit the current section name.
23440 Defaults to @samp{""}.
23444 @deftypevr {@code{cgit-configuration} parameter} string section-sort
23445 Flag which, when set to @samp{1}, will sort the sections on the
23446 repository listing by name.
23448 Defaults to @samp{""}.
23452 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
23453 A number which, if defined prior to repository-directory, specifies how
23454 many path elements from each repo path to use as a default section name.
23456 Defaults to @samp{0}.
23460 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
23461 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
23464 Defaults to @samp{#f}.
23468 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
23469 Specifies a command which will be invoked to format plaintext blobs in
23472 Defaults to @samp{""}.
23476 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
23477 Specifies the number of branches to display in the repository "summary"
23480 Defaults to @samp{10}.
23484 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
23485 Specifies the number of log entries to display in the repository
23488 Defaults to @samp{10}.
23492 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
23493 Specifies the number of tags to display in the repository "summary"
23496 Defaults to @samp{10}.
23500 @deftypevr {@code{cgit-configuration} parameter} string strict-export
23501 Filename which, if specified, needs to be present within the repository
23502 for cgit to allow access to that repository.
23504 Defaults to @samp{""}.
23508 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
23509 URL which, if specified, will be used as root for all cgit links.
23511 Defaults to @samp{"/"}.
23515 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
23516 A list of @dfn{cgit-repo} records to use with config.
23518 Defaults to @samp{()}.
23520 Available @code{repository-cgit-configuration} fields are:
23522 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
23523 A mask of snapshot formats for this repo that cgit generates links for,
23524 restricted by the global @code{snapshots} setting.
23526 Defaults to @samp{()}.
23530 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
23531 Override the default @code{source-filter}.
23533 Defaults to @samp{""}.
23537 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
23538 The relative URL used to access the repository.
23540 Defaults to @samp{""}.
23544 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
23545 Override the default @code{about-filter}.
23547 Defaults to @samp{""}.
23551 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
23552 Flag which, when set to @samp{age}, enables date ordering in the branch
23553 ref list, and when set to @samp{name} enables ordering by branch name.
23555 Defaults to @samp{""}.
23559 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
23560 A list of URLs which can be used to clone repo.
23562 Defaults to @samp{()}.
23566 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
23567 Override the default @code{commit-filter}.
23569 Defaults to @samp{""}.
23573 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
23574 Flag which, when set to @samp{date}, enables strict date ordering in the
23575 commit log, and when set to @samp{topo} enables strict topological
23578 Defaults to @samp{""}.
23582 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
23583 The name of the default branch for this repository. If no such branch
23584 exists in the repository, the first branch name (when sorted) is used as
23585 default instead. By default branch pointed to by HEAD, or "master" if
23586 there is no suitable HEAD.
23588 Defaults to @samp{""}.
23592 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
23593 The value to show as repository description.
23595 Defaults to @samp{""}.
23599 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
23600 The value to show as repository homepage.
23602 Defaults to @samp{""}.
23606 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
23607 Override the default @code{email-filter}.
23609 Defaults to @samp{""}.
23613 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
23614 A flag which can be used to disable the global setting
23615 @code{enable-commit-graph?}.
23617 Defaults to @samp{disabled}.
23621 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
23622 A flag which can be used to disable the global setting
23623 @code{enable-log-filecount?}.
23625 Defaults to @samp{disabled}.
23629 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
23630 A flag which can be used to disable the global setting
23631 @code{enable-log-linecount?}.
23633 Defaults to @samp{disabled}.
23637 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
23638 Flag which, when set to @code{#t}, will make cgit display remote
23639 branches in the summary and refs views.
23641 Defaults to @samp{disabled}.
23645 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
23646 A flag which can be used to override the global setting
23647 @code{enable-subject-links?}.
23649 Defaults to @samp{disabled}.
23653 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
23654 A flag which can be used to override the global setting
23655 @code{enable-html-serving?}.
23657 Defaults to @samp{disabled}.
23661 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
23662 Flag which, when set to @code{#t}, hides the repository from the
23665 Defaults to @samp{#f}.
23669 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
23670 Flag which, when set to @samp{#t}, ignores the repository.
23672 Defaults to @samp{#f}.
23676 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
23677 URL which specifies the source of an image which will be used as a logo
23678 on this repo’s pages.
23680 Defaults to @samp{""}.
23684 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
23685 URL loaded when clicking on the cgit logo image.
23687 Defaults to @samp{""}.
23691 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
23692 Override the default @code{owner-filter}.
23694 Defaults to @samp{""}.
23698 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
23699 Text which will be used as the formatstring for a hyperlink when a
23700 submodule is printed in a directory listing. The arguments for the
23701 formatstring are the path and SHA1 of the submodule commit.
23703 Defaults to @samp{""}.
23707 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
23708 Text which will be used as the formatstring for a hyperlink when a
23709 submodule with the specified subdirectory path is printed in a directory
23712 Defaults to @samp{()}.
23716 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
23717 Override the default maximum statistics period.
23719 Defaults to @samp{""}.
23723 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
23724 The value to show as repository name.
23726 Defaults to @samp{""}.
23730 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
23731 A value used to identify the owner of the repository.
23733 Defaults to @samp{""}.
23737 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
23738 An absolute path to the repository directory.
23740 Defaults to @samp{""}.
23744 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
23745 A path (relative to repo) which specifies a file to include verbatim as
23746 the "About" page for this repo.
23748 Defaults to @samp{""}.
23752 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
23753 The name of the current repository section - all repositories defined
23754 after this option will inherit the current section name.
23756 Defaults to @samp{""}.
23760 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
23761 Extra options will be appended to cgitrc file.
23763 Defaults to @samp{()}.
23769 @deftypevr {@code{cgit-configuration} parameter} list extra-options
23770 Extra options will be appended to cgitrc file.
23772 Defaults to @samp{()}.
23777 @c %end of fragment
23779 However, it could be that you just want to get a @code{cgitrc} up and
23780 running. In that case, you can pass an @code{opaque-cgit-configuration}
23781 as a record to @code{cgit-service-type}. As its name indicates, an
23782 opaque configuration does not have easy reflective capabilities.
23784 Available @code{opaque-cgit-configuration} fields are:
23786 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
23790 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
23791 The contents of the @code{cgitrc}, as a string.
23794 For example, if your @code{cgitrc} is just the empty string, you
23795 could instantiate a cgit service like this:
23798 (service cgit-service-type
23799 (opaque-cgit-configuration
23803 @subsubheading Gitolite Service
23805 @cindex Gitolite service
23806 @cindex Git, hosting
23807 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
23808 repositories on a central server.
23810 Gitolite can handle multiple repositories and users, and supports flexible
23811 configuration of the permissions for the users on the repositories.
23813 The following example will configure Gitolite using the default @code{git}
23814 user, and the provided SSH public key.
23817 (service gitolite-service-type
23818 (gitolite-configuration
23819 (admin-pubkey (plain-file
23821 "ssh-rsa AAAA... guix@@example.com"))))
23824 Gitolite is configured through a special admin repository which you can clone,
23825 for example, if you setup Gitolite on @code{example.com}, you would run the
23826 following command to clone the admin repository.
23829 git clone git@@example.com:gitolite-admin
23832 When the Gitolite service is activated, the provided @code{admin-pubkey} will
23833 be inserted in to the @file{keydir} directory in the gitolite-admin
23834 repository. If this results in a change in the repository, it will be
23835 committed using the message ``gitolite setup by GNU Guix''.
23837 @deftp {Data Type} gitolite-configuration
23838 Data type representing the configuration for @code{gitolite-service-type}.
23841 @item @code{package} (default: @var{gitolite})
23842 Gitolite package to use.
23844 @item @code{user} (default: @var{git})
23845 User to use for Gitolite. This will be user that you use when accessing
23848 @item @code{group} (default: @var{git})
23849 Group to use for Gitolite.
23851 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
23852 Directory in which to store the Gitolite configuration and repositories.
23854 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
23855 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
23856 representing the configuration for Gitolite.
23858 @item @code{admin-pubkey} (default: @var{#f})
23859 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
23860 setup Gitolite. This will be inserted in to the @file{keydir} directory
23861 within the gitolite-admin repository.
23863 To specify the SSH key as a string, use the @code{plain-file} function.
23866 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
23872 @deftp {Data Type} gitolite-rc-file
23873 Data type representing the Gitolite RC file.
23876 @item @code{umask} (default: @code{#o0077})
23877 This controls the permissions Gitolite sets on the repositories and their
23880 A value like @code{#o0027} will give read access to the group used by Gitolite
23881 (by default: @code{git}). This is necessary when using Gitolite with software
23882 like cgit or gitweb.
23884 @item @code{git-config-keys} (default: @code{""})
23885 Gitolite allows you to set git config values using the "config" keyword. This
23886 setting allows control over the config keys to accept.
23888 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
23889 Set the role names allowed to be used by users running the perms command.
23891 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
23892 This setting controls the commands and features to enable within Gitolite.
23898 @node Game Services
23899 @subsection Game Services
23901 @subsubheading The Battle for Wesnoth Service
23903 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
23904 based tactical strategy game, with several single player campaigns, and
23905 multiplayer games (both networked and local).
23907 @defvar {Scheme Variable} wesnothd-service-type
23908 Service type for the wesnothd service. Its value must be a
23909 @code{wesnothd-configuration} object. To run wesnothd in the default
23910 configuration, instantiate it as:
23913 (service wesnothd-service-type)
23917 @deftp {Data Type} wesnothd-configuration
23918 Data type representing the configuration of @command{wesnothd}.
23921 @item @code{package} (default: @code{wesnoth-server})
23922 The wesnoth server package to use.
23924 @item @code{port} (default: @code{15000})
23925 The port to bind the server to.
23929 @node Miscellaneous Services
23930 @subsection Miscellaneous Services
23932 @cindex fingerprint
23933 @subsubheading Fingerprint Service
23935 The @code{(gnu services authentication)} module provides a DBus service to
23936 read and identify fingerprints via a fingerprint sensor.
23938 @defvr {Scheme Variable} fprintd-service-type
23939 The service type for @command{fprintd}, which provides the fingerprint
23940 reading capability.
23943 (service fprintd-service-type)
23948 @subsubheading System Control Service
23950 The @code{(gnu services sysctl)} provides a service to configure kernel
23951 parameters at boot.
23953 @defvr {Scheme Variable} sysctl-service-type
23954 The service type for @command{sysctl}, which modifies kernel parameters
23955 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
23959 (service sysctl-service-type
23960 (sysctl-configuration
23961 (settings '(("net.ipv4.ip_forward" . "1")))))
23965 @deftp {Data Type} sysctl-configuration
23966 The data type representing the configuration of @command{sysctl}.
23969 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
23970 The @command{sysctl} executable to use.
23972 @item @code{settings} (default: @code{'()})
23973 An association list specifies kernel parameters and their values.
23978 @subsubheading PC/SC Smart Card Daemon Service
23980 The @code{(gnu services security-token)} module provides the following service
23981 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
23982 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
23983 manager that coordinates communications with smart card readers, smart cards
23984 and cryptographic tokens that are connected to the system.
23986 @defvr {Scheme Variable} pcscd-service-type
23987 Service type for the @command{pcscd} service. Its value must be a
23988 @code{pcscd-configuration} object. To run pcscd in the default
23989 configuration, instantiate it as:
23992 (service pcscd-service-type)
23996 @deftp {Data Type} pcscd-configuration
23997 The data type representing the configuration of @command{pcscd}.
24000 @item @code{pcsc-lite} (default: @code{pcsc-lite})
24001 The pcsc-lite package that provides pcscd.
24002 @item @code{usb-drivers} (default: @code{(list ccid)})
24003 List of packages that provide USB drivers to pcscd. Drivers are expected to be
24004 under @file{pcsc/drivers} in the store directory of the package.
24009 @subsubheading Lirc Service
24011 The @code{(gnu services lirc)} module provides the following service.
24013 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
24014 [#:device #f] [#:driver #f] [#:config-file #f] @
24015 [#:extra-options '()]
24016 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
24017 decodes infrared signals from remote controls.
24019 Optionally, @var{device}, @var{driver} and @var{config-file}
24020 (configuration file name) may be specified. See @command{lircd} manual
24023 Finally, @var{extra-options} is a list of additional command-line options
24024 passed to @command{lircd}.
24028 @subsubheading Spice Service
24030 The @code{(gnu services spice)} module provides the following service.
24032 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
24033 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
24034 that enables sharing the clipboard with a vm and setting the guest display
24035 resolution when the graphical console window resizes.
24038 @cindex inputattach
24039 @subsubheading inputattach Service
24041 @cindex tablet input, for Xorg
24042 @cindex touchscreen input, for Xorg
24043 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
24044 use input devices such as Wacom tablets, touchscreens, or joysticks with the
24045 Xorg display server.
24047 @deffn {Scheme Variable} inputattach-service-type
24048 Type of a service that runs @command{inputattach} on a device and
24049 dispatches events from it.
24052 @deftp {Data Type} inputattach-configuration
24054 @item @code{device-type} (default: @code{"wacom"})
24055 The type of device to connect to. Run @command{inputattach --help}, from the
24056 @code{inputattach} package, to see the list of supported device types.
24058 @item @code{device} (default: @code{"/dev/ttyS0"})
24059 The device file to connect to the device.
24061 @item @code{log-file} (default: @code{#f})
24062 If true, this must be the name of a file to log messages to.
24066 @subsection Dictionary Services
24068 The @code{(gnu services dict)} module provides the following service:
24070 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
24071 Return a service that runs the @command{dicod} daemon, an implementation
24072 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
24074 The optional @var{config} argument specifies the configuration for
24075 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
24076 default it serves the GNU Collaborative International Dictonary of English.
24078 You can add @command{open localhost} to your @file{~/.dico} file to make
24079 @code{localhost} the default server for @command{dico} client
24080 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
24083 @deftp {Data Type} dicod-configuration
24084 Data type representing the configuration of dicod.
24087 @item @code{dico} (default: @var{dico})
24088 Package object of the GNU Dico dictionary server.
24090 @item @code{interfaces} (default: @var{'("localhost")})
24091 This is the list of IP addresses and ports and possibly socket file
24092 names to listen to (@pxref{Server Settings, @code{listen} directive,,
24093 dico, GNU Dico Manual}).
24095 @item @code{handlers} (default: @var{'()})
24096 List of @code{<dicod-handler>} objects denoting handlers (module instances).
24098 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
24099 List of @code{<dicod-database>} objects denoting dictionaries to be served.
24103 @deftp {Data Type} dicod-handler
24104 Data type representing a dictionary handler (module instance).
24108 Name of the handler (module instance).
24110 @item @code{module} (default: @var{#f})
24111 Name of the dicod module of the handler (instance). If it is @code{#f},
24112 the module has the same name as the handler.
24113 (@pxref{Modules,,, dico, GNU Dico Manual}).
24115 @item @code{options}
24116 List of strings or gexps representing the arguments for the module handler
24120 @deftp {Data Type} dicod-database
24121 Data type representing a dictionary database.
24125 Name of the database, will be used in DICT commands.
24127 @item @code{handler}
24128 Name of the dicod handler (module instance) used by this database
24129 (@pxref{Handlers,,, dico, GNU Dico Manual}).
24131 @item @code{complex?} (default: @var{#f})
24132 Whether the database configuration complex. The complex configuration
24133 will need a corresponding @code{<dicod-handler>} object, otherwise not.
24135 @item @code{options}
24136 List of strings or gexps representing the arguments for the database
24137 (@pxref{Databases,,, dico, GNU Dico Manual}).
24141 @defvr {Scheme Variable} %dicod-database:gcide
24142 A @code{<dicod-database>} object serving the GNU Collaborative International
24143 Dictionary of English using the @code{gcide} package.
24146 The following is an example @code{dicod-service} configuration.
24149 (dicod-service #:config
24150 (dicod-configuration
24151 (handlers (list (dicod-handler
24155 (list #~(string-append "dbdir=" #$wordnet))))))
24156 (databases (list (dicod-database
24159 (handler "wordnet")
24160 (options '("database=wn")))
24161 %dicod-database:gcide))))
24165 @subsubheading Docker Service
24167 The @code{(gnu services docker)} module provides the following services.
24169 @defvr {Scheme Variable} docker-service-type
24171 This is the type of the service that runs @url{https://www.docker.com,Docker},
24172 a daemon that can execute application bundles (sometimes referred to as
24173 ``containers'') in isolated environments.
24177 @deftp {Data Type} docker-configuration
24178 This is the data type representing the configuration of Docker and Containerd.
24182 @item @code{package} (default: @code{docker})
24183 The Docker package to use.
24185 @item @code{containerd} (default: @var{containerd})
24186 The Containerd package to use.
24192 @subsubheading Auditd Service
24194 The @code{(gnu services auditd)} module provides the following service.
24196 @defvr {Scheme Variable} auditd-service-type
24198 This is the type of the service that runs
24199 @url{https://people.redhat.com/sgrubb/audit/,auditd},
24200 a daemon that tracks security-relevant information on your system.
24202 Examples of things that can be tracked:
24212 Failed login attempts
24219 @command{auditctl} from the @code{audit} package can be used in order
24220 to add or remove events to be tracked (until the next reboot).
24221 In order to permanently track events, put the command line arguments
24222 of auditctl into @file{/etc/audit/audit.rules}.
24223 @command{aureport} from the @code{audit} package can be used in order
24224 to view a report of all recorded events.
24225 The audit daemon usually logs into the directory @file{/var/log/audit}.
24229 @deftp {Data Type} auditd-configuration
24230 This is the data type representing the configuration of auditd.
24234 @item @code{audit} (default: @code{audit})
24235 The audit package to use.
24240 @defvr {Scheme Variable} singularity-service-type
24241 This is the type of the service that allows you to run
24242 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
24243 create and run application bundles (aka. ``containers''). The value for this
24244 service is the Singularity package to use.
24246 The service does not install a daemon; instead, it installs helper programs as
24247 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
24248 @command{singularity run} and similar commands.
24252 @subsubheading Nix service
24254 The @code{(gnu services nix)} module provides the following service.
24256 @defvr {Scheme Variable} nix-service-type
24258 This is the type of the service that runs build daemon of the
24259 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
24263 (use-modules (gnu))
24264 (use-service-modules nix)
24265 (use-package-modules package-management)
24269 (packages (append (list nix)
24272 (services (append (list (service nix-service-type))
24276 After @command{guix system reconfigure} configure Nix for your user:
24279 @item Add a Nix channel and update it. See
24280 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
24282 @item Create a symlink to your profile and activate Nix profile:
24286 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
24287 $ source /run/current-system/profile/etc/profile.d/nix.sh
24292 @node Setuid Programs
24293 @section Setuid Programs
24295 @cindex setuid programs
24296 Some programs need to run with ``root'' privileges, even when they are
24297 launched by unprivileged users. A notorious example is the
24298 @command{passwd} program, which users can run to change their
24299 password, and which needs to access the @file{/etc/passwd} and
24300 @file{/etc/shadow} files---something normally restricted to root, for
24301 obvious security reasons. To address that, these executables are
24302 @dfn{setuid-root}, meaning that they always run with root privileges
24303 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
24304 for more info about the setuid mechanism.)
24306 The store itself @emph{cannot} contain setuid programs: that would be a
24307 security issue since any user on the system can write derivations that
24308 populate the store (@pxref{The Store}). Thus, a different mechanism is
24309 used: instead of changing the setuid bit directly on files that are in
24310 the store, we let the system administrator @emph{declare} which programs
24311 should be setuid root.
24313 The @code{setuid-programs} field of an @code{operating-system}
24314 declaration contains a list of G-expressions denoting the names of
24315 programs to be setuid-root (@pxref{Using the Configuration System}).
24316 For instance, the @command{passwd} program, which is part of the Shadow
24317 package, can be designated by this G-expression (@pxref{G-Expressions}):
24320 #~(string-append #$shadow "/bin/passwd")
24323 A default set of setuid programs is defined by the
24324 @code{%setuid-programs} variable of the @code{(gnu system)} module.
24326 @defvr {Scheme Variable} %setuid-programs
24327 A list of G-expressions denoting common programs that are setuid-root.
24329 The list includes commands such as @command{passwd}, @command{ping},
24330 @command{su}, and @command{sudo}.
24333 Under the hood, the actual setuid programs are created in the
24334 @file{/run/setuid-programs} directory at system activation time. The
24335 files in this directory refer to the ``real'' binaries, which are in the
24338 @node X.509 Certificates
24339 @section X.509 Certificates
24341 @cindex HTTPS, certificates
24342 @cindex X.509 certificates
24344 Web servers available over HTTPS (that is, HTTP over the transport-layer
24345 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
24346 that the client can then use to @emph{authenticate} the server. To do
24347 that, clients verify that the server's certificate is signed by a
24348 so-called @dfn{certificate authority} (CA). But to verify the CA's
24349 signature, clients must have first acquired the CA's certificate.
24351 Web browsers such as GNU@tie{}IceCat include their own set of CA
24352 certificates, such that they are able to verify CA signatures
24355 However, most other programs that can talk HTTPS---@command{wget},
24356 @command{git}, @command{w3m}, etc.---need to be told where CA
24357 certificates can be found.
24359 @cindex @code{nss-certs}
24360 In Guix, this is done by adding a package that provides certificates
24361 to the @code{packages} field of the @code{operating-system} declaration
24362 (@pxref{operating-system Reference}). Guix includes one such package,
24363 @code{nss-certs}, which is a set of CA certificates provided as part of
24364 Mozilla's Network Security Services.
24366 Note that it is @emph{not} part of @code{%base-packages}, so you need to
24367 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
24368 most applications and libraries look for certificates by default, points
24369 to the certificates installed globally.
24371 Unprivileged users, including users of Guix on a foreign distro,
24372 can also install their own certificate package in
24373 their profile. A number of environment variables need to be defined so
24374 that applications and libraries know where to find them. Namely, the
24375 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
24376 variables. Some applications add their own environment variables; for
24377 instance, the Git version control system honors the certificate bundle
24378 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
24379 would typically run something like:
24382 $ guix install nss-certs
24383 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
24384 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
24385 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
24388 As another example, R requires the @code{CURL_CA_BUNDLE} environment
24389 variable to point to a certificate bundle, so you would have to run
24390 something like this:
24393 $ guix install nss-certs
24394 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
24397 For other applications you may want to look up the required environment
24398 variable in the relevant documentation.
24401 @node Name Service Switch
24402 @section Name Service Switch
24404 @cindex name service switch
24406 The @code{(gnu system nss)} module provides bindings to the
24407 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
24408 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
24409 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
24410 extended with new ``name'' lookup methods for system databases, which
24411 includes host names, service names, user accounts, and more (@pxref{Name
24412 Service Switch, System Databases and Name Service Switch,, libc, The GNU
24413 C Library Reference Manual}).
24415 The NSS configuration specifies, for each system database, which lookup
24416 method is to be used, and how the various methods are chained
24417 together---for instance, under which circumstances NSS should try the
24418 next method in the list. The NSS configuration is given in the
24419 @code{name-service-switch} field of @code{operating-system} declarations
24420 (@pxref{operating-system Reference, @code{name-service-switch}}).
24423 @cindex .local, host name lookup
24424 As an example, the declaration below configures the NSS to use the
24425 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
24426 back-end}, which supports host name lookups over multicast DNS (mDNS)
24427 for host names ending in @code{.local}:
24430 (name-service-switch
24431 (hosts (list %files ;first, check /etc/hosts
24433 ;; If the above did not succeed, try
24434 ;; with 'mdns_minimal'.
24436 (name "mdns_minimal")
24438 ;; 'mdns_minimal' is authoritative for
24439 ;; '.local'. When it returns "not found",
24440 ;; no need to try the next methods.
24441 (reaction (lookup-specification
24442 (not-found => return))))
24444 ;; Then fall back to DNS.
24448 ;; Finally, try with the "full" 'mdns'.
24453 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
24454 contains this configuration, so you will not have to type it if all you
24455 want is to have @code{.local} host lookup working.
24457 Note that, in this case, in addition to setting the
24458 @code{name-service-switch} of the @code{operating-system} declaration,
24459 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
24460 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
24461 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
24462 to the name service cache daemon (@pxref{Base Services,
24463 @code{nscd-service}}).
24465 For convenience, the following variables provide typical NSS
24468 @defvr {Scheme Variable} %default-nss
24469 This is the default name service switch configuration, a
24470 @code{name-service-switch} object.
24473 @defvr {Scheme Variable} %mdns-host-lookup-nss
24474 This is the name service switch configuration with support for host name
24475 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
24478 The reference for name service switch configuration is given below. It
24479 is a direct mapping of the configuration file format of the C library , so
24480 please refer to the C library manual for more information (@pxref{NSS
24481 Configuration File,,, libc, The GNU C Library Reference Manual}).
24482 Compared to the configuration file format of libc NSS, it has the advantage
24483 not only of adding this warm parenthetic feel that we like, but also
24484 static checks: you will know about syntax errors and typos as soon as you
24485 run @command{guix system}.
24487 @deftp {Data Type} name-service-switch
24489 This is the data type representation the configuration of libc's name
24490 service switch (NSS). Each field below represents one of the supported
24507 The system databases handled by the NSS. Each of these fields must be a
24508 list of @code{<name-service>} objects (see below).
24512 @deftp {Data Type} name-service
24514 This is the data type representing an actual name service and the
24515 associated lookup action.
24519 A string denoting the name service (@pxref{Services in the NSS
24520 configuration,,, libc, The GNU C Library Reference Manual}).
24522 Note that name services listed here must be visible to nscd. This is
24523 achieved by passing the @code{#:name-services} argument to
24524 @code{nscd-service} the list of packages providing the needed name
24525 services (@pxref{Base Services, @code{nscd-service}}).
24528 An action specified using the @code{lookup-specification} macro
24529 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
24530 Reference Manual}). For example:
24533 (lookup-specification (unavailable => continue)
24534 (success => return))
24539 @node Initial RAM Disk
24540 @section Initial RAM Disk
24543 @cindex initial RAM disk
24544 For bootstrapping purposes, the Linux-Libre kernel is passed an
24545 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
24546 root file system as well as an initialization script. The latter is
24547 responsible for mounting the real root file system, and for loading any
24548 kernel modules that may be needed to achieve that.
24550 The @code{initrd-modules} field of an @code{operating-system}
24551 declaration allows you to specify Linux-libre kernel modules that must
24552 be available in the initrd. In particular, this is where you would list
24553 modules needed to actually drive the hard disk where your root partition
24554 is---although the default value of @code{initrd-modules} should cover
24555 most use cases. For example, assuming you need the @code{megaraid_sas}
24556 module in addition to the default modules to be able to access your root
24557 file system, you would write:
24562 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
24565 @defvr {Scheme Variable} %base-initrd-modules
24566 This is the list of kernel modules included in the initrd by default.
24569 Furthermore, if you need lower-level customization, the @code{initrd}
24570 field of an @code{operating-system} declaration allows
24571 you to specify which initrd you would like to use. The @code{(gnu
24572 system linux-initrd)} module provides three ways to build an initrd: the
24573 high-level @code{base-initrd} procedure and the low-level
24574 @code{raw-initrd} and @code{expression->initrd} procedures.
24576 The @code{base-initrd} procedure is intended to cover most common uses.
24577 For example, if you want to add a bunch of kernel modules to be loaded
24578 at boot time, you can define the @code{initrd} field of the operating
24579 system declaration like this:
24582 (initrd (lambda (file-systems . rest)
24583 ;; Create a standard initrd but set up networking
24584 ;; with the parameters QEMU expects by default.
24585 (apply base-initrd file-systems
24586 #:qemu-networking? #t
24590 The @code{base-initrd} procedure also handles common use cases that
24591 involves using the system as a QEMU guest, or as a ``live'' system with
24592 volatile root file system.
24594 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
24595 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
24596 such as trying to guess which kernel modules and packages should be included
24597 to the initrd. An example use of @code{raw-initrd} is when a user has
24598 a custom Linux kernel configuration and default kernel modules included by
24599 @code{base-initrd} are not available.
24601 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
24602 honors several options passed on the Linux kernel command line
24603 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
24604 @code{-append} option of QEMU), notably:
24607 @item --load=@var{boot}
24608 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
24609 program, once it has mounted the root file system.
24611 Guix uses this option to yield control to a boot program that runs the
24612 service activation programs and then spawns the GNU@tie{}Shepherd, the
24613 initialization system.
24615 @item --root=@var{root}
24616 Mount @var{root} as the root file system. @var{root} can be a
24617 device name like @code{/dev/sda1}, a file system label, or a file system
24620 @item --system=@var{system}
24621 Have @file{/run/booted-system} and @file{/run/current-system} point to
24624 @item modprobe.blacklist=@var{modules}@dots{}
24625 @cindex module, black-listing
24626 @cindex black list, of kernel modules
24627 Instruct the initial RAM disk as well as the @command{modprobe} command
24628 (from the kmod package) to refuse to load @var{modules}. @var{modules}
24629 must be a comma-separated list of module names---e.g.,
24630 @code{usbkbd,9pnet}.
24633 Start a read-eval-print loop (REPL) from the initial RAM disk before it
24634 tries to load kernel modules and to mount the root file system. Our
24635 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
24636 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
24637 Manual}, for more information on Guile's REPL.
24641 Now that you know all the features that initial RAM disks produced by
24642 @code{base-initrd} and @code{raw-initrd} provide,
24643 here is how to use it and customize it further.
24646 @cindex initial RAM disk
24647 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
24648 [#:linux-modules '()] [#:mapped-devices '()] @
24649 [#:keyboard-layout #f] @
24650 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
24651 Return a derivation that builds a raw initrd. @var{file-systems} is
24652 a list of file systems to be mounted by the initrd, possibly in addition to
24653 the root file system specified on the kernel command line via @code{--root}.
24654 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
24655 @var{mapped-devices} is a list of device mappings to realize before
24656 @var{file-systems} are mounted (@pxref{Mapped Devices}).
24657 @var{helper-packages} is a list of packages to be copied in the initrd. It may
24658 include @code{e2fsck/static} or other packages needed by the initrd to check
24659 the root file system.
24661 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
24662 the desired console keyboard layout. This is done before @var{mapped-devices}
24663 are set up and before @var{file-systems} are mounted such that, should the
24664 user need to enter a passphrase or use the REPL, this happens using the
24665 intended keyboard layout.
24667 When @var{qemu-networking?} is true, set up networking with the standard QEMU
24668 parameters. When @var{virtio?} is true, load additional modules so that the
24669 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
24671 When @var{volatile-root?} is true, the root file system is writable but any changes
24675 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
24676 [#:mapped-devices '()] [#:keyboard-layout #f] @
24677 [#:qemu-networking? #f] [#:volatile-root? #f] @
24678 [#:linux-modules '()]
24679 Return as a file-like object a generic initrd, with kernel
24680 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
24681 mounted by the initrd, possibly in addition to the root file system specified
24682 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
24683 mappings to realize before @var{file-systems} are mounted.
24685 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
24686 the desired console keyboard layout. This is done before @var{mapped-devices}
24687 are set up and before @var{file-systems} are mounted such that, should the
24688 user need to enter a passphrase or use the REPL, this happens using the
24689 intended keyboard layout.
24691 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
24693 The initrd is automatically populated with all the kernel modules necessary
24694 for @var{file-systems} and for the given options. Additional kernel
24695 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
24696 loaded at boot time in the order in which they appear.
24699 Needless to say, the initrds we produce and use embed a
24700 statically-linked Guile, and the initialization program is a Guile
24701 program. That gives a lot of flexibility. The
24702 @code{expression->initrd} procedure builds such an initrd, given the
24703 program to run in that initrd.
24705 @deffn {Scheme Procedure} expression->initrd @var{exp} @
24706 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
24707 Return as a file-like object a Linux initrd (a gzipped cpio archive)
24708 containing @var{guile} and that evaluates @var{exp}, a G-expression,
24709 upon booting. All the derivations referenced by @var{exp} are
24710 automatically copied to the initrd.
24713 @node Bootloader Configuration
24714 @section Bootloader Configuration
24717 @cindex boot loader
24719 The operating system supports multiple bootloaders. The bootloader is
24720 configured using @code{bootloader-configuration} declaration. All the
24721 fields of this structure are bootloader agnostic except for one field,
24722 @code{bootloader} that indicates the bootloader to be configured and
24725 Some of the bootloaders do not honor every field of
24726 @code{bootloader-configuration}. For instance, the extlinux
24727 bootloader does not support themes and thus ignores the @code{theme}
24730 @deftp {Data Type} bootloader-configuration
24731 The type of a bootloader configuration declaration.
24735 @item @code{bootloader}
24736 @cindex EFI, bootloader
24737 @cindex UEFI, bootloader
24738 @cindex BIOS, bootloader
24739 The bootloader to use, as a @code{bootloader} object. For now
24740 @code{grub-bootloader}, @code{grub-efi-bootloader},
24741 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
24743 @vindex grub-efi-bootloader
24744 @code{grub-efi-bootloader} allows to boot on modern systems using the
24745 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
24746 use if the installation image contains a @file{/sys/firmware/efi} directory
24747 when you boot it on your system.
24749 @vindex grub-bootloader
24750 @code{grub-bootloader} allows you to boot in particular Intel-based machines
24751 in ``legacy'' BIOS mode.
24753 @cindex ARM, bootloaders
24754 @cindex AArch64, bootloaders
24755 Available bootloaders are described in @code{(gnu bootloader @dots{})}
24756 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
24757 of bootloaders for a wide range of ARM and AArch64 systems, using the
24758 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
24760 @item @code{target}
24761 This is a string denoting the target onto which to install the
24764 The interpretation depends on the bootloader in question. For
24765 @code{grub-bootloader}, for example, it should be a device name understood by
24766 the bootloader @command{installer} command, such as @code{/dev/sda} or
24767 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
24768 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
24769 system, usually @file{/boot/efi}.
24771 @item @code{menu-entries} (default: @code{()})
24772 A possibly empty list of @code{menu-entry} objects (see below), denoting
24773 entries to appear in the bootloader menu, in addition to the current
24774 system entry and the entry pointing to previous system generations.
24776 @item @code{default-entry} (default: @code{0})
24777 The index of the default boot menu entry. Index 0 is for the entry of the
24780 @item @code{timeout} (default: @code{5})
24781 The number of seconds to wait for keyboard input before booting. Set to
24782 0 to boot immediately, and to -1 to wait indefinitely.
24784 @cindex keyboard layout, for the bootloader
24785 @item @code{keyboard-layout} (default: @code{#f})
24786 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
24787 layout, usually US@tie{}English (``qwerty'').
24789 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
24793 This option is currently ignored by bootloaders other than @code{grub} and
24797 @item @code{theme} (default: @var{#f})
24798 The bootloader theme object describing the theme to use. If no theme
24799 is provided, some bootloaders might use a default theme, that's true
24802 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
24803 The output terminals used for the bootloader boot menu, as a list of
24804 symbols. GRUB accepts the values: @code{console}, @code{serial},
24805 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
24806 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
24807 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
24808 configuration,,, grub,GNU GRUB manual}).
24810 @item @code{terminal-inputs} (default: @code{'()})
24811 The input terminals used for the bootloader boot menu, as a list of
24812 symbols. For GRUB, the default is the native platform terminal as
24813 determined at run-time. GRUB accepts the values: @code{console},
24814 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
24815 @code{usb_keyboard}. This field corresponds to the GRUB variable
24816 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
24819 @item @code{serial-unit} (default: @code{#f})
24820 The serial unit used by the bootloader, as an integer from 0 to 3.
24821 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
24822 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24824 @item @code{serial-speed} (default: @code{#f})
24825 The speed of the serial interface, as an integer. For GRUB, the
24826 default value is chosen at run-time; currently GRUB chooses
24827 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24834 Should you want to list additional boot menu entries @i{via} the
24835 @code{menu-entries} field above, you will need to create them with the
24836 @code{menu-entry} form. For example, imagine you want to be able to
24837 boot another distro (hard to imagine!), you can define a menu entry
24842 (label "The Other Distro")
24843 (linux "/boot/old/vmlinux-2.6.32")
24844 (linux-arguments '("root=/dev/sda2"))
24845 (initrd "/boot/old/initrd"))
24850 @deftp {Data Type} menu-entry
24851 The type of an entry in the bootloader menu.
24856 The label to show in the menu---e.g., @code{"GNU"}.
24859 The Linux kernel image to boot, for example:
24862 (file-append linux-libre "/bzImage")
24865 For GRUB, it is also possible to specify a device explicitly in the
24866 file path using GRUB's device naming convention (@pxref{Naming
24867 convention,,, grub, GNU GRUB manual}), for example:
24870 "(hd0,msdos1)/boot/vmlinuz"
24873 If the device is specified explicitly as above, then the @code{device}
24874 field is ignored entirely.
24876 @item @code{linux-arguments} (default: @code{()})
24877 The list of extra Linux kernel command-line arguments---e.g.,
24878 @code{("console=ttyS0")}.
24880 @item @code{initrd}
24881 A G-Expression or string denoting the file name of the initial RAM disk
24882 to use (@pxref{G-Expressions}).
24883 @item @code{device} (default: @code{#f})
24884 The device where the kernel and initrd are to be found---i.e., for GRUB,
24885 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
24887 This may be a file system label (a string), a file system UUID (a
24888 bytevector, @pxref{File Systems}), or @code{#f}, in which case
24889 the bootloader will search the device containing the file specified by
24890 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
24891 must @emph{not} be an OS device name such as @file{/dev/sda1}.
24896 @c FIXME: Write documentation once it's stable.
24897 For now only GRUB has theme support. GRUB themes are created using
24898 the @code{grub-theme} form, which is not documented yet.
24900 @defvr {Scheme Variable} %default-theme
24901 This is the default GRUB theme used by the operating system if no
24902 @code{theme} field is specified in @code{bootloader-configuration}
24905 It comes with a fancy background image displaying the GNU and Guix
24910 @node Invoking guix system
24911 @section Invoking @code{guix system}
24913 Once you have written an operating system declaration as seen in the
24914 previous section, it can be @dfn{instantiated} using the @command{guix
24915 system} command. The synopsis is:
24918 guix system @var{options}@dots{} @var{action} @var{file}
24921 @var{file} must be the name of a file containing an
24922 @code{operating-system} declaration. @var{action} specifies how the
24923 operating system is instantiated. Currently the following values are
24928 Display available service type definitions that match the given regular
24929 expressions, sorted by relevance:
24932 $ guix system search console font
24933 name: console-fonts
24934 location: gnu/services/base.scm:729:2
24935 extends: shepherd-root
24936 description: Install the given fonts on the specified ttys (fonts are
24937 + per virtual console on GNU/Linux). The value of this service is a list
24938 + of tty/font pairs like:
24940 + '(("tty1" . "LatGrkCyr-8x16"))
24944 location: gnu/services/base.scm:1048:2
24945 extends: shepherd-root
24946 description: Provide console login using the `mingetty' program.
24950 location: gnu/services/base.scm:775:2
24952 description: Provide a console log-in service as specified by its
24953 + configuration value, a `login-configuration' object.
24959 As for @command{guix package --search}, the result is written in
24960 @code{recutils} format, which makes it easy to filter the output
24961 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
24964 Build the operating system described in @var{file}, activate it, and
24965 switch to it@footnote{This action (and the related actions
24966 @code{switch-generation} and @code{roll-back}) are usable only on
24967 systems already running Guix System.}.
24969 This effects all the configuration specified in @var{file}: user
24970 accounts, system services, global package list, setuid programs, etc.
24971 The command starts system services specified in @var{file} that are not
24972 currently running; if a service is currently running this command will
24973 arrange for it to be upgraded the next time it is stopped (e.g.@: by
24974 @code{herd stop X} or @code{herd restart X}).
24976 This command creates a new generation whose number is one greater than
24977 the current generation (as reported by @command{guix system
24978 list-generations}). If that generation already exists, it will be
24979 overwritten. This behavior mirrors that of @command{guix package}
24980 (@pxref{Invoking guix package}).
24982 It also adds a bootloader menu entry for the new OS configuration,
24983 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
24984 entries for older configurations to a submenu, allowing you to choose
24985 an older system generation at boot time should you need it.
24988 @c The paragraph below refers to the problem discussed at
24989 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
24990 It is highly recommended to run @command{guix pull} once before you run
24991 @command{guix system reconfigure} for the first time (@pxref{Invoking
24992 guix pull}). Failing to do that you would see an older version of Guix
24993 once @command{reconfigure} has completed.
24996 @item switch-generation
24997 @cindex generations
24998 Switch to an existing system generation. This action atomically
24999 switches the system profile to the specified system generation. It
25000 also rearranges the system's existing bootloader menu entries. It
25001 makes the menu entry for the specified system generation the default,
25002 and it moves the entries for the other generatiors to a submenu, if
25003 supported by the bootloader being used. The next time the system
25004 boots, it will use the specified system generation.
25006 The bootloader itself is not being reinstalled when using this
25007 command. Thus, the installed bootloader is used with an updated
25008 configuration file.
25010 The target generation can be specified explicitly by its generation
25011 number. For example, the following invocation would switch to system
25015 guix system switch-generation 7
25018 The target generation can also be specified relative to the current
25019 generation with the form @code{+N} or @code{-N}, where @code{+3} means
25020 ``3 generations ahead of the current generation,'' and @code{-1} means
25021 ``1 generation prior to the current generation.'' When specifying a
25022 negative value such as @code{-1}, you must precede it with @code{--} to
25023 prevent it from being parsed as an option. For example:
25026 guix system switch-generation -- -1
25029 Currently, the effect of invoking this action is @emph{only} to switch
25030 the system profile to an existing generation and rearrange the
25031 bootloader menu entries. To actually start using the target system
25032 generation, you must reboot after running this action. In the future,
25033 it will be updated to do the same things as @command{reconfigure},
25034 like activating and deactivating services.
25036 This action will fail if the specified generation does not exist.
25039 @cindex rolling back
25040 Switch to the preceding system generation. The next time the system
25041 boots, it will use the preceding system generation. This is the inverse
25042 of @command{reconfigure}, and it is exactly the same as invoking
25043 @command{switch-generation} with an argument of @code{-1}.
25045 Currently, as with @command{switch-generation}, you must reboot after
25046 running this action to actually start using the preceding system
25049 @item delete-generations
25050 @cindex deleting system generations
25051 @cindex saving space
25052 Delete system generations, making them candidates for garbage collection
25053 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
25056 This works in the same way as @command{guix package --delete-generations}
25057 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
25058 arguments, all system generations but the current one are deleted:
25061 guix system delete-generations
25064 You can also select the generations you want to delete. The example below
25065 deletes all the system generations that are more than two month old:
25068 guix system delete-generations 2m
25071 Running this command automatically reinstalls the bootloader with an updated
25072 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
25073 longer lists the generations that have been deleted.
25076 Build the derivation of the operating system, which includes all the
25077 configuration files and programs needed to boot and run the system.
25078 This action does not actually install anything.
25081 Populate the given directory with all the files necessary to run the
25082 operating system specified in @var{file}. This is useful for first-time
25083 installations of Guix System. For instance:
25086 guix system init my-os-config.scm /mnt
25089 copies to @file{/mnt} all the store items required by the configuration
25090 specified in @file{my-os-config.scm}. This includes configuration
25091 files, packages, and so on. It also creates other essential files
25092 needed for the system to operate correctly---e.g., the @file{/etc},
25093 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
25095 This command also installs bootloader on the target specified in
25096 @file{my-os-config}, unless the @option{--no-bootloader} option was
25100 @cindex virtual machine
25102 @anchor{guix system vm}
25103 Build a virtual machine that contains the operating system declared in
25104 @var{file}, and return a script to run that virtual machine (VM).
25107 The @code{vm} action and others below
25108 can use KVM support in the Linux-libre kernel. Specifically, if the
25109 machine has hardware virtualization support, the corresponding
25110 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
25111 must exist and be readable and writable by the user and by the
25112 build users of the daemon (@pxref{Build Environment Setup}).
25115 Arguments given to the script are passed to QEMU as in the example
25116 below, which enables networking and requests 1@tie{}GiB of RAM for the
25120 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
25123 The VM shares its store with the host system.
25125 Additional file systems can be shared between the host and the VM using
25126 the @code{--share} and @code{--expose} command-line options: the former
25127 specifies a directory to be shared with write access, while the latter
25128 provides read-only access to the shared directory.
25130 The example below creates a VM in which the user's home directory is
25131 accessible read-only, and where the @file{/exchange} directory is a
25132 read-write mapping of @file{$HOME/tmp} on the host:
25135 guix system vm my-config.scm \
25136 --expose=$HOME --share=$HOME/tmp=/exchange
25139 On GNU/Linux, the default is to boot directly to the kernel; this has
25140 the advantage of requiring only a very tiny root disk image since the
25141 store of the host can then be mounted.
25143 The @code{--full-boot} option forces a complete boot sequence, starting
25144 with the bootloader. This requires more disk space since a root image
25145 containing at least the kernel, initrd, and bootloader data files must
25146 be created. The @code{--image-size} option can be used to specify the
25149 @cindex System images, creation in various formats
25150 @cindex Creating system images in various formats
25153 @itemx docker-image
25154 Return a virtual machine, disk image, or Docker image of the operating
25155 system declared in @var{file} that stands alone. By default,
25156 @command{guix system} estimates the size of the image needed to store
25157 the system, but you can use the @option{--image-size} option to specify
25158 a value. Docker images are built to contain exactly what they need, so
25159 the @option{--image-size} option is ignored in the case of
25160 @code{docker-image}.
25162 You can specify the root file system type by using the
25163 @option{--file-system-type} option. It defaults to @code{ext4}.
25165 When using @code{vm-image}, the returned image is in qcow2 format, which
25166 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
25167 for more information on how to run the image in a virtual machine.
25169 When using @code{disk-image}, a raw disk image is produced; it can be
25170 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
25171 the device corresponding to a USB stick, one can copy the image to it
25172 using the following command:
25175 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
25178 When using @code{docker-image}, a Docker image is produced. Guix builds
25179 the image from scratch, not from a pre-existing Docker base image. As a
25180 result, it contains @emph{exactly} what you define in the operating
25181 system configuration file. You can then load the image and launch a
25182 Docker container using commands like the following:
25185 image_id="`docker load < guix-system-docker-image.tar.gz`"
25186 container_id="`docker create $image_id`"
25187 docker start $container_id
25190 This command starts a new Docker container from the specified image. It
25191 will boot the Guix system in the usual manner, which means it will
25192 start any services you have defined in the operating system
25193 configuration. You can get an interactive shell running in the container
25194 using @command{docker exec}:
25197 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
25200 Depending on what you run in the Docker container, it
25201 may be necessary to give the container additional permissions. For
25202 example, if you intend to build software using Guix inside of the Docker
25203 container, you may need to pass the @option{--privileged} option to
25204 @code{docker create}.
25207 Return a script to run the operating system declared in @var{file}
25208 within a container. Containers are a set of lightweight isolation
25209 mechanisms provided by the kernel Linux-libre. Containers are
25210 substantially less resource-demanding than full virtual machines since
25211 the kernel, shared objects, and other resources can be shared with the
25212 host system; this also means they provide thinner isolation.
25214 Currently, the script must be run as root in order to support more than
25215 a single user and group. The container shares its store with the host
25218 As with the @code{vm} action (@pxref{guix system vm}), additional file
25219 systems to be shared between the host and container can be specified
25220 using the @option{--share} and @option{--expose} options:
25223 guix system container my-config.scm \
25224 --expose=$HOME --share=$HOME/tmp=/exchange
25228 This option requires Linux-libre 3.19 or newer.
25233 @var{options} can contain any of the common build options (@pxref{Common
25234 Build Options}). In addition, @var{options} can contain one of the
25238 @item --expression=@var{expr}
25239 @itemx -e @var{expr}
25240 Consider the operating-system @var{expr} evaluates to.
25241 This is an alternative to specifying a file which evaluates to an
25243 This is used to generate the Guix system installer @pxref{Building the
25244 Installation Image}).
25246 @item --system=@var{system}
25247 @itemx -s @var{system}
25248 Attempt to build for @var{system} instead of the host system type.
25249 This works as per @command{guix build} (@pxref{Invoking guix build}).
25253 Return the derivation file name of the given operating system without
25256 @item --file-system-type=@var{type}
25257 @itemx -t @var{type}
25258 For the @code{disk-image} action, create a file system of the given
25259 @var{type} on the image.
25261 When this option is omitted, @command{guix system} uses @code{ext4}.
25263 @cindex ISO-9660 format
25264 @cindex CD image format
25265 @cindex DVD image format
25266 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
25267 for burning on CDs and DVDs.
25269 @item --image-size=@var{size}
25270 For the @code{vm-image} and @code{disk-image} actions, create an image
25271 of the given @var{size}. @var{size} may be a number of bytes, or it may
25272 include a unit as a suffix (@pxref{Block size, size specifications,,
25273 coreutils, GNU Coreutils}).
25275 When this option is omitted, @command{guix system} computes an estimate
25276 of the image size as a function of the size of the system declared in
25281 For the @code{container} action, allow containers to access the host network,
25282 that is, do not create a network namespace.
25284 @item --root=@var{file}
25285 @itemx -r @var{file}
25286 Make @var{file} a symlink to the result, and register it as a garbage
25289 @item --skip-checks
25290 Skip pre-installation safety checks.
25292 By default, @command{guix system init} and @command{guix system
25293 reconfigure} perform safety checks: they make sure the file systems that
25294 appear in the @code{operating-system} declaration actually exist
25295 (@pxref{File Systems}), and that any Linux kernel modules that may be
25296 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
25297 RAM Disk}). Passing this option skips these tests altogether.
25300 @cindex on-error strategy
25301 @cindex error strategy
25302 @item --on-error=@var{strategy}
25303 Apply @var{strategy} when an error occurs when reading @var{file}.
25304 @var{strategy} may be one of the following:
25307 @item nothing-special
25308 Report the error concisely and exit. This is the default strategy.
25311 Likewise, but also display a backtrace.
25314 Report the error and enter Guile's debugger. From there, you can run
25315 commands such as @code{,bt} to get a backtrace, @code{,locals} to
25316 display local variable values, and more generally inspect the state of the
25317 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
25318 a list of available debugging commands.
25322 Once you have built, configured, re-configured, and re-re-configured
25323 your Guix installation, you may find it useful to list the operating
25324 system generations available on disk---and that you can choose from the
25325 bootloader boot menu:
25329 @item list-generations
25330 List a summary of each generation of the operating system available on
25331 disk, in a human-readable way. This is similar to the
25332 @option{--list-generations} option of @command{guix package}
25333 (@pxref{Invoking guix package}).
25335 Optionally, one can specify a pattern, with the same syntax that is used
25336 in @command{guix package --list-generations}, to restrict the list of
25337 generations displayed. For instance, the following command displays
25338 generations that are up to 10 days old:
25341 $ guix system list-generations 10d
25346 The @command{guix system} command has even more to offer! The following
25347 sub-commands allow you to visualize how your system services relate to
25350 @anchor{system-extension-graph}
25353 @item extension-graph
25354 Emit in Dot/Graphviz format to standard output the @dfn{service
25355 extension graph} of the operating system defined in @var{file}
25356 (@pxref{Service Composition}, for more information on service
25362 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
25365 produces a PDF file showing the extension relations among services.
25367 @anchor{system-shepherd-graph}
25368 @item shepherd-graph
25369 Emit in Dot/Graphviz format to standard output the @dfn{dependency
25370 graph} of shepherd services of the operating system defined in
25371 @var{file}. @xref{Shepherd Services}, for more information and for an
25376 @node Running Guix in a VM
25377 @section Running Guix in a Virtual Machine
25379 @cindex virtual machine
25380 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
25382 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
25383 This image is a compressed image in QCOW format. You will first need to
25384 decompress with @command{xz -d}, and then you can pass it to an emulator such
25385 as QEMU (see below for details).
25387 This image boots the Xfce graphical environment and it contains some
25388 commonly-used tools. You can install more software in the image by running
25389 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
25390 also reconfigure the system based on its initial configuration file available
25391 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
25393 Instead of using this pre-built image, one can also build their own virtual
25394 machine image using @command{guix system vm-image} (@pxref{Invoking guix
25395 system}). The returned image is in qcow2 format, which the
25396 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
25399 If you built your own image, you must copy it out of the store
25400 (@pxref{The Store}) and give yourself permission to write to the copy
25401 before you can use it. When invoking QEMU, you must choose a system
25402 emulator that is suitable for your hardware platform. Here is a minimal
25403 QEMU invocation that will boot the result of @command{guix system
25404 vm-image} on x86_64 hardware:
25407 $ qemu-system-x86_64 \
25408 -net user -net nic,model=virtio \
25409 -enable-kvm -m 512 \
25410 -device virtio-blk,drive=myhd \
25411 -drive if=none,file=/tmp/qemu-image,id=myhd
25414 Here is what each of these options means:
25417 @item qemu-system-x86_64
25418 This specifies the hardware platform to emulate. This should match the
25422 Enable the unprivileged user-mode network stack. The guest OS can
25423 access the host but not vice versa. This is the simplest way to get the
25426 @item -net nic,model=virtio
25427 You must create a network interface of a given model. If you do not
25428 create a NIC, the boot will fail. Assuming your hardware platform is
25429 x86_64, you can get a list of available NIC models by running
25430 @command{qemu-system-x86_64 -net nic,model=help}.
25433 If your system has hardware virtualization extensions, enabling the
25434 virtual machine support (KVM) of the Linux kernel will make things run
25437 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
25439 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
25440 which may be insufficient for some operations.
25442 @item -device virtio-blk,drive=myhd
25443 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
25444 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
25445 better performance than if it were emulating a complete disk drive. See the
25446 QEMU and KVM documentation for more info.
25448 @item -drive if=none,file=/tmp/qemu-image,id=myhd
25449 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
25450 the ``myhd'' drive.
25453 The default @command{run-vm.sh} script that is returned by an invocation of
25454 @command{guix system vm} does not add a @command{-net user} flag by default.
25455 To get network access from within the vm add the @code{(dhcp-client-service)}
25456 to your system definition and start the VM using
25457 @command{`guix system vm config.scm` -net user}. An important caveat of using
25458 @command{-net user} for networking is that @command{ping} will not work, because
25459 it uses the ICMP protocol. You'll have to use a different command to check for
25460 network connectivity, for example @command{guix download}.
25462 @subsection Connecting Through SSH
25466 To enable SSH inside a VM you need to add an SSH server like
25467 @code{openssh-service-type} to your VM (@pxref{Networking Services,
25468 @code{openssh-service-type}}). In addition you need to forward the SSH port,
25469 22 by default, to the host. You can do this with
25472 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
25475 To connect to the VM you can run
25478 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
25481 The @command{-p} tells @command{ssh} the port you want to connect to.
25482 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
25483 every time you modify your @command{config.scm} file and the
25484 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
25485 connection to an unknown host every time you connect.
25487 @subsection Using @command{virt-viewer} with Spice
25489 As an alternative to the default @command{qemu} graphical client you can
25490 use the @command{remote-viewer} from the @command{virt-viewer} package. To
25491 connect pass the @command{-spice port=5930,disable-ticketing} flag to
25492 @command{qemu}. See previous section for further information on how to do this.
25494 Spice also allows you to do some nice stuff like share your clipboard with your
25495 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
25498 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
25499 -chardev spicevmc,name=vdagent,id=vdagent
25500 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
25501 name=com.redhat.spice.0
25504 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
25506 @node Defining Services
25507 @section Defining Services
25509 The previous sections show the available services and how one can combine
25510 them in an @code{operating-system} declaration. But how do we define
25511 them in the first place? And what is a service anyway?
25514 * Service Composition:: The model for composing services.
25515 * Service Types and Services:: Types and services.
25516 * Service Reference:: API reference.
25517 * Shepherd Services:: A particular type of service.
25520 @node Service Composition
25521 @subsection Service Composition
25525 Here we define a @dfn{service} as, broadly, something that extends the
25526 functionality of the operating system. Often a service is a process---a
25527 @dfn{daemon}---started when the system boots: a secure shell server, a
25528 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
25529 whose execution can be triggered by another daemon---e.g., an FTP server
25530 started by @command{inetd} or a D-Bus service activated by
25531 @command{dbus-daemon}. Occasionally, a service does not map to a
25532 daemon. For instance, the ``account'' service collects user accounts
25533 and makes sure they exist when the system runs; the ``udev'' service
25534 collects device management rules and makes them available to the eudev
25535 daemon; the @file{/etc} service populates the @file{/etc} directory
25538 @cindex service extensions
25539 Guix system services are connected by @dfn{extensions}. For instance, the
25540 secure shell service @emph{extends} the Shepherd---the
25541 initialization system, running as PID@tie{}1---by giving it the command
25542 lines to start and stop the secure shell daemon (@pxref{Networking
25543 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
25544 service by passing it its @file{.service} specification, and extends the
25545 udev service by passing it device management rules (@pxref{Desktop
25546 Services, @code{upower-service}}); the Guix daemon service extends the
25547 Shepherd by passing it the command lines to start and stop the daemon,
25548 and extends the account service by passing it a list of required build
25549 user accounts (@pxref{Base Services}).
25551 All in all, services and their ``extends'' relations form a directed
25552 acyclic graph (DAG). If we represent services as boxes and extensions
25553 as arrows, a typical system might provide something like this:
25555 @image{images/service-graph,,5in,Typical service extension graph.}
25557 @cindex system service
25558 At the bottom, we see the @dfn{system service}, which produces the
25559 directory containing everything to run and boot the system, as returned
25560 by the @command{guix system build} command. @xref{Service Reference},
25561 to learn about the other service types shown here.
25562 @xref{system-extension-graph, the @command{guix system extension-graph}
25563 command}, for information on how to generate this representation for a
25564 particular operating system definition.
25566 @cindex service types
25567 Technically, developers can define @dfn{service types} to express these
25568 relations. There can be any number of services of a given type on the
25569 system---for instance, a system running two instances of the GNU secure
25570 shell server (lsh) has two instances of @code{lsh-service-type}, with
25571 different parameters.
25573 The following section describes the programming interface for service
25574 types and services.
25576 @node Service Types and Services
25577 @subsection Service Types and Services
25579 A @dfn{service type} is a node in the DAG described above. Let us start
25580 with a simple example, the service type for the Guix build daemon
25581 (@pxref{Invoking guix-daemon}):
25584 (define guix-service-type
25588 (list (service-extension shepherd-root-service-type guix-shepherd-service)
25589 (service-extension account-service-type guix-accounts)
25590 (service-extension activation-service-type guix-activation)))
25591 (default-value (guix-configuration))))
25595 It defines three things:
25599 A name, whose sole purpose is to make inspection and debugging easier.
25602 A list of @dfn{service extensions}, where each extension designates the
25603 target service type and a procedure that, given the parameters of the
25604 service, returns a list of objects to extend the service of that type.
25606 Every service type has at least one service extension. The only
25607 exception is the @dfn{boot service type}, which is the ultimate service.
25610 Optionally, a default value for instances of this type.
25613 In this example, @code{guix-service-type} extends three services:
25616 @item shepherd-root-service-type
25617 The @code{guix-shepherd-service} procedure defines how the Shepherd
25618 service is extended. Namely, it returns a @code{<shepherd-service>}
25619 object that defines how @command{guix-daemon} is started and stopped
25620 (@pxref{Shepherd Services}).
25622 @item account-service-type
25623 This extension for this service is computed by @code{guix-accounts},
25624 which returns a list of @code{user-group} and @code{user-account}
25625 objects representing the build user accounts (@pxref{Invoking
25628 @item activation-service-type
25629 Here @code{guix-activation} is a procedure that returns a gexp, which is
25630 a code snippet to run at ``activation time''---e.g., when the service is
25634 A service of this type is instantiated like this:
25637 (service guix-service-type
25638 (guix-configuration
25640 (use-substitutes? #f)))
25643 The second argument to the @code{service} form is a value representing
25644 the parameters of this specific service instance.
25645 @xref{guix-configuration-type, @code{guix-configuration}}, for
25646 information about the @code{guix-configuration} data type. When the
25647 value is omitted, the default value specified by
25648 @code{guix-service-type} is used:
25651 (service guix-service-type)
25654 @code{guix-service-type} is quite simple because it extends other
25655 services but is not extensible itself.
25657 @c @subsubsubsection Extensible Service Types
25659 The service type for an @emph{extensible} service looks like this:
25662 (define udev-service-type
25663 (service-type (name 'udev)
25665 (list (service-extension shepherd-root-service-type
25666 udev-shepherd-service)))
25668 (compose concatenate) ;concatenate the list of rules
25669 (extend (lambda (config rules)
25671 (($ <udev-configuration> udev initial-rules)
25672 (udev-configuration
25673 (udev udev) ;the udev package to use
25674 (rules (append initial-rules rules)))))))))
25677 This is the service type for the
25678 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
25679 management daemon}. Compared to the previous example, in addition to an
25680 extension of @code{shepherd-root-service-type}, we see two new fields:
25684 This is the procedure to @dfn{compose} the list of extensions to
25685 services of this type.
25687 Services can extend the udev service by passing it lists of rules; we
25688 compose those extensions simply by concatenating them.
25691 This procedure defines how the value of the service is @dfn{extended} with
25692 the composition of the extensions.
25694 Udev extensions are composed into a list of rules, but the udev service
25695 value is itself a @code{<udev-configuration>} record. So here, we
25696 extend that record by appending the list of rules it contains to the
25697 list of contributed rules.
25700 This is a string giving an overview of the service type. The string can
25701 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
25702 @command{guix system search} command searches these strings and displays
25703 them (@pxref{Invoking guix system}).
25706 There can be only one instance of an extensible service type such as
25707 @code{udev-service-type}. If there were more, the
25708 @code{service-extension} specifications would be ambiguous.
25710 Still here? The next section provides a reference of the programming
25711 interface for services.
25713 @node Service Reference
25714 @subsection Service Reference
25716 We have seen an overview of service types (@pxref{Service Types and
25717 Services}). This section provides a reference on how to manipulate
25718 services and service types. This interface is provided by the
25719 @code{(gnu services)} module.
25721 @deffn {Scheme Procedure} service @var{type} [@var{value}]
25722 Return a new service of @var{type}, a @code{<service-type>} object (see
25723 below.) @var{value} can be any object; it represents the parameters of
25724 this particular service instance.
25726 When @var{value} is omitted, the default value specified by @var{type}
25727 is used; if @var{type} does not specify a default value, an error is
25730 For instance, this:
25733 (service openssh-service-type)
25737 is equivalent to this:
25740 (service openssh-service-type
25741 (openssh-configuration))
25744 In both cases the result is an instance of @code{openssh-service-type}
25745 with the default configuration.
25748 @deffn {Scheme Procedure} service? @var{obj}
25749 Return true if @var{obj} is a service.
25752 @deffn {Scheme Procedure} service-kind @var{service}
25753 Return the type of @var{service}---i.e., a @code{<service-type>} object.
25756 @deffn {Scheme Procedure} service-value @var{service}
25757 Return the value associated with @var{service}. It represents its
25761 Here is an example of how a service is created and manipulated:
25765 (service nginx-service-type
25766 (nginx-configuration
25768 (log-directory log-directory)
25769 (run-directory run-directory)
25770 (file config-file))))
25775 (eq? (service-kind s) nginx-service-type)
25779 The @code{modify-services} form provides a handy way to change the
25780 parameters of some of the services of a list such as
25781 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
25782 evaluates to a list of services. Of course, you could always use
25783 standard list combinators such as @code{map} and @code{fold} to do that
25784 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
25785 @code{modify-services} simply provides a more concise form for this
25788 @deffn {Scheme Syntax} modify-services @var{services} @
25789 (@var{type} @var{variable} => @var{body}) @dots{}
25791 Modify the services listed in @var{services} according to the given
25792 clauses. Each clause has the form:
25795 (@var{type} @var{variable} => @var{body})
25798 where @var{type} is a service type---e.g.,
25799 @code{guix-service-type}---and @var{variable} is an identifier that is
25800 bound within the @var{body} to the service parameters---e.g., a
25801 @code{guix-configuration} instance---of the original service of that
25804 The @var{body} should evaluate to the new service parameters, which will
25805 be used to configure the new service. This new service will replace the
25806 original in the resulting list. Because a service's service parameters
25807 are created using @code{define-record-type*}, you can write a succinct
25808 @var{body} that evaluates to the new service parameters by using the
25809 @code{inherit} feature that @code{define-record-type*} provides.
25811 @xref{Using the Configuration System}, for example usage.
25815 Next comes the programming interface for service types. This is
25816 something you want to know when writing new service definitions, but not
25817 necessarily when simply looking for ways to customize your
25818 @code{operating-system} declaration.
25820 @deftp {Data Type} service-type
25821 @cindex service type
25822 This is the representation of a @dfn{service type} (@pxref{Service Types
25827 This is a symbol, used only to simplify inspection and debugging.
25829 @item @code{extensions}
25830 A non-empty list of @code{<service-extension>} objects (see below).
25832 @item @code{compose} (default: @code{#f})
25833 If this is @code{#f}, then the service type denotes services that cannot
25834 be extended---i.e., services that do not receive ``values'' from other
25837 Otherwise, it must be a one-argument procedure. The procedure is called
25838 by @code{fold-services} and is passed a list of values collected from
25839 extensions. It may return any single value.
25841 @item @code{extend} (default: @code{#f})
25842 If this is @code{#f}, services of this type cannot be extended.
25844 Otherwise, it must be a two-argument procedure: @code{fold-services}
25845 calls it, passing it the initial value of the service as the first
25846 argument and the result of applying @code{compose} to the extension
25847 values as the second argument. It must return a value that is a valid
25848 parameter value for the service instance.
25851 @xref{Service Types and Services}, for examples.
25854 @deffn {Scheme Procedure} service-extension @var{target-type} @
25856 Return a new extension for services of type @var{target-type}.
25857 @var{compute} must be a one-argument procedure: @code{fold-services}
25858 calls it, passing it the value associated with the service that provides
25859 the extension; it must return a valid value for the target service.
25862 @deffn {Scheme Procedure} service-extension? @var{obj}
25863 Return true if @var{obj} is a service extension.
25866 Occasionally, you might want to simply extend an existing service. This
25867 involves creating a new service type and specifying the extension of
25868 interest, which can be verbose; the @code{simple-service} procedure
25869 provides a shorthand for this.
25871 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
25872 Return a service that extends @var{target} with @var{value}. This works
25873 by creating a singleton service type @var{name}, of which the returned
25874 service is an instance.
25876 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
25880 (simple-service 'my-mcron-job mcron-service-type
25881 #~(job '(next-hour (3)) "guix gc -F 2G"))
25885 At the core of the service abstraction lies the @code{fold-services}
25886 procedure, which is responsible for ``compiling'' a list of services
25887 down to a single directory that contains everything needed to boot and
25888 run the system---the directory shown by the @command{guix system build}
25889 command (@pxref{Invoking guix system}). In essence, it propagates
25890 service extensions down the service graph, updating each node parameters
25891 on the way, until it reaches the root node.
25893 @deffn {Scheme Procedure} fold-services @var{services} @
25894 [#:target-type @var{system-service-type}]
25895 Fold @var{services} by propagating their extensions down to the root of
25896 type @var{target-type}; return the root service adjusted accordingly.
25899 Lastly, the @code{(gnu services)} module also defines several essential
25900 service types, some of which are listed below.
25902 @defvr {Scheme Variable} system-service-type
25903 This is the root of the service graph. It produces the system directory
25904 as returned by the @command{guix system build} command.
25907 @defvr {Scheme Variable} boot-service-type
25908 The type of the ``boot service'', which produces the @dfn{boot script}.
25909 The boot script is what the initial RAM disk runs when booting.
25912 @defvr {Scheme Variable} etc-service-type
25913 The type of the @file{/etc} service. This service is used to create
25914 files under @file{/etc} and can be extended by
25915 passing it name/file tuples such as:
25918 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
25921 In this example, the effect would be to add an @file{/etc/issue} file
25922 pointing to the given file.
25925 @defvr {Scheme Variable} setuid-program-service-type
25926 Type for the ``setuid-program service''. This service collects lists of
25927 executable file names, passed as gexps, and adds them to the set of
25928 setuid-root programs on the system (@pxref{Setuid Programs}).
25931 @defvr {Scheme Variable} profile-service-type
25932 Type of the service that populates the @dfn{system profile}---i.e., the
25933 programs under @file{/run/current-system/profile}. Other services can
25934 extend it by passing it lists of packages to add to the system profile.
25938 @node Shepherd Services
25939 @subsection Shepherd Services
25941 @cindex shepherd services
25943 @cindex init system
25944 The @code{(gnu services shepherd)} module provides a way to define
25945 services managed by the GNU@tie{}Shepherd, which is the
25946 initialization system---the first process that is started when the
25947 system boots, also known as PID@tie{}1
25948 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
25950 Services in the Shepherd can depend on each other. For instance, the
25951 SSH daemon may need to be started after the syslog daemon has been
25952 started, which in turn can only happen once all the file systems have
25953 been mounted. The simple operating system defined earlier (@pxref{Using
25954 the Configuration System}) results in a service graph like this:
25956 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
25958 You can actually generate such a graph for any operating system
25959 definition using the @command{guix system shepherd-graph} command
25960 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
25962 The @code{%shepherd-root-service} is a service object representing
25963 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
25964 by passing it lists of @code{<shepherd-service>} objects.
25966 @deftp {Data Type} shepherd-service
25967 The data type representing a service managed by the Shepherd.
25970 @item @code{provision}
25971 This is a list of symbols denoting what the service provides.
25973 These are the names that may be passed to @command{herd start},
25974 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
25975 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
25976 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
25978 @item @code{requirement} (default: @code{'()})
25979 List of symbols denoting the Shepherd services this one depends on.
25981 @cindex one-shot services, for the Shepherd
25982 @item @code{one-shot?} (default: @code{#f})
25983 Whether this service is @dfn{one-shot}. One-shot services stop immediately
25984 after their @code{start} action has completed. @xref{Slots of services,,,
25985 shepherd, The GNU Shepherd Manual}, for more info.
25987 @item @code{respawn?} (default: @code{#t})
25988 Whether to restart the service when it stops, for instance when the
25989 underlying process dies.
25992 @itemx @code{stop} (default: @code{#~(const #f)})
25993 The @code{start} and @code{stop} fields refer to the Shepherd's
25994 facilities to start and stop processes (@pxref{Service De- and
25995 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
25996 G-expressions that get expanded in the Shepherd configuration file
25997 (@pxref{G-Expressions}).
25999 @item @code{actions} (default: @code{'()})
26000 @cindex actions, of Shepherd services
26001 This is a list of @code{shepherd-action} objects (see below) defining
26002 @dfn{actions} supported by the service, in addition to the standard
26003 @code{start} and @code{stop} actions. Actions listed here become available as
26004 @command{herd} sub-commands:
26007 herd @var{action} @var{service} [@var{arguments}@dots{}]
26010 @item @code{auto-start?} (default: @code{#t})
26011 Whether this service should be started automatically by the Shepherd. If it
26012 is @code{#f} the service has to be started manually with @code{herd start}.
26014 @item @code{documentation}
26015 A documentation string, as shown when running:
26018 herd doc @var{service-name}
26021 where @var{service-name} is one of the symbols in @code{provision}
26022 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
26024 @item @code{modules} (default: @code{%default-modules})
26025 This is the list of modules that must be in scope when @code{start} and
26026 @code{stop} are evaluated.
26031 @deftp {Data Type} shepherd-action
26032 This is the data type that defines additional actions implemented by a
26033 Shepherd service (see above).
26037 Symbol naming the action.
26039 @item documentation
26040 This is a documentation string for the action. It can be viewed by running:
26043 herd doc @var{service} action @var{action}
26047 This should be a gexp that evaluates to a procedure of at least one argument,
26048 which is the ``running value'' of the service (@pxref{Slots of services,,,
26049 shepherd, The GNU Shepherd Manual}).
26052 The following example defines an action called @code{say-hello} that kindly
26058 (documentation "Say hi!")
26059 (procedure #~(lambda (running . args)
26060 (format #t "Hello, friend! arguments: ~s\n"
26065 Assuming this action is added to the @code{example} service, then you can do:
26068 # herd say-hello example
26069 Hello, friend! arguments: ()
26070 # herd say-hello example a b c
26071 Hello, friend! arguments: ("a" "b" "c")
26074 This, as you can see, is a fairly sophisticated way to say hello.
26075 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
26079 @defvr {Scheme Variable} shepherd-root-service-type
26080 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
26082 This is the service type that extensions target when they want to create
26083 shepherd services (@pxref{Service Types and Services}, for an example).
26084 Each extension must pass a list of @code{<shepherd-service>}.
26087 @defvr {Scheme Variable} %shepherd-root-service
26088 This service represents PID@tie{}1.
26092 @node Documentation
26093 @chapter Documentation
26095 @cindex documentation, searching for
26096 @cindex searching for documentation
26097 @cindex Info, documentation format
26099 @cindex manual pages
26100 In most cases packages installed with Guix come with documentation.
26101 There are two main documentation formats: ``Info'', a browseable
26102 hypertext format used for GNU software, and ``manual pages'' (or ``man
26103 pages''), the linear documentation format traditionally found on Unix.
26104 Info manuals are accessed with the @command{info} command or with Emacs,
26105 and man pages are accessed using @command{man}.
26107 You can look for documentation of software installed on your system by
26108 keyword. For example, the following command searches for information
26109 about ``TLS'' in Info manuals:
26113 "(emacs)Network Security" -- STARTTLS
26114 "(emacs)Network Security" -- TLS
26115 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
26116 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
26121 The command below searches for the same keyword in man pages:
26125 SSL (7) - OpenSSL SSL/TLS library
26126 certtool (1) - GnuTLS certificate tool
26130 These searches are purely local to your computer so you have the
26131 guarantee that documentation you find corresponds to what you have
26132 actually installed, you can access it off-line, and your privacy is
26135 Once you have these results, you can view the relevant documentation by
26139 $ info "(gnutls)Core TLS API"
26149 Info manuals contain sections and indices as well as hyperlinks like
26150 those found in Web pages. The @command{info} reader (@pxref{Top, Info
26151 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
26152 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
26153 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
26154 Introduction}, for an introduction to Info navigation.
26156 @node Installing Debugging Files
26157 @chapter Installing Debugging Files
26159 @cindex debugging files
26160 Program binaries, as produced by the GCC compilers for instance, are
26161 typically written in the ELF format, with a section containing
26162 @dfn{debugging information}. Debugging information is what allows the
26163 debugger, GDB, to map binary code to source code; it is required to
26164 debug a compiled program in good conditions.
26166 The problem with debugging information is that is takes up a fair amount
26167 of disk space. For example, debugging information for the GNU C Library
26168 weighs in at more than 60 MiB. Thus, as a user, keeping all the
26169 debugging info of all the installed programs is usually not an option.
26170 Yet, space savings should not come at the cost of an impediment to
26171 debugging---especially in the GNU system, which should make it easier
26172 for users to exert their computing freedom (@pxref{GNU Distribution}).
26174 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
26175 mechanism that allows users to get the best of both worlds: debugging
26176 information can be stripped from the binaries and stored in separate
26177 files. GDB is then able to load debugging information from those files,
26178 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
26181 The GNU distribution takes advantage of this by storing debugging
26182 information in the @code{lib/debug} sub-directory of a separate package
26183 output unimaginatively called @code{debug} (@pxref{Packages with
26184 Multiple Outputs}). Users can choose to install the @code{debug} output
26185 of a package when they need it. For instance, the following command
26186 installs the debugging information for the GNU C Library and for GNU
26190 guix install glibc:debug guile:debug
26193 GDB must then be told to look for debug files in the user's profile, by
26194 setting the @code{debug-file-directory} variable (consider setting it
26195 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
26199 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
26202 From there on, GDB will pick up debugging information from the
26203 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
26205 In addition, you will most likely want GDB to be able to show the source
26206 code being debugged. To do that, you will have to unpack the source
26207 code of the package of interest (obtained with @code{guix build
26208 --source}, @pxref{Invoking guix build}), and to point GDB to that source
26209 directory using the @code{directory} command (@pxref{Source Path,
26210 @code{directory},, gdb, Debugging with GDB}).
26212 @c XXX: keep me up-to-date
26213 The @code{debug} output mechanism in Guix is implemented by the
26214 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
26215 opt-in---debugging information is available only for the packages
26216 with definitions explicitly declaring a @code{debug} output. This may be
26217 changed to opt-out in the future if our build farm servers can handle
26218 the load. To check whether a package has a @code{debug} output, use
26219 @command{guix package --list-available} (@pxref{Invoking guix package}).
26222 @node Security Updates
26223 @chapter Security Updates
26225 @cindex security updates
26226 @cindex security vulnerabilities
26227 Occasionally, important security vulnerabilities are discovered in software
26228 packages and must be patched. Guix developers try hard to keep track of
26229 known vulnerabilities and to apply fixes as soon as possible in the
26230 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
26231 containing only security updates.) The @command{guix lint} tool helps
26232 developers find out about vulnerable versions of software packages in the
26237 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
26238 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
26239 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
26243 @xref{Invoking guix lint}, for more information.
26246 As of version @value{VERSION}, the feature described below is considered
26250 Guix follows a functional
26251 package management discipline (@pxref{Introduction}), which implies
26252 that, when a package is changed, @emph{every package that depends on it}
26253 must be rebuilt. This can significantly slow down the deployment of
26254 fixes in core packages such as libc or Bash, since basically the whole
26255 distribution would need to be rebuilt. Using pre-built binaries helps
26256 (@pxref{Substitutes}), but deployment may still take more time than
26260 To address this, Guix implements @dfn{grafts}, a mechanism that allows
26261 for fast deployment of critical updates without the costs associated
26262 with a whole-distribution rebuild. The idea is to rebuild only the
26263 package that needs to be patched, and then to ``graft'' it onto packages
26264 explicitly installed by the user and that were previously referring to
26265 the original package. The cost of grafting is typically very low, and
26266 order of magnitudes lower than a full rebuild of the dependency chain.
26268 @cindex replacements of packages, for grafts
26269 For instance, suppose a security update needs to be applied to Bash.
26270 Guix developers will provide a package definition for the ``fixed''
26271 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
26272 Packages}). Then, the original package definition is augmented with a
26273 @code{replacement} field pointing to the package containing the bug fix:
26280 (replacement bash-fixed)))
26283 From there on, any package depending directly or indirectly on Bash---as
26284 reported by @command{guix gc --requisites} (@pxref{Invoking guix
26285 gc})---that is installed is automatically ``rewritten'' to refer to
26286 @code{bash-fixed} instead of @code{bash}. This grafting process takes
26287 time proportional to the size of the package, usually less than a
26288 minute for an ``average'' package on a recent machine. Grafting is
26289 recursive: when an indirect dependency requires grafting, then grafting
26290 ``propagates'' up to the package that the user is installing.
26292 Currently, the length of the name and version of the graft and that of
26293 the package it replaces (@code{bash-fixed} and @code{bash} in the example
26294 above) must be equal. This restriction mostly comes from the fact that
26295 grafting works by patching files, including binary files, directly.
26296 Other restrictions may apply: for instance, when adding a graft to a
26297 package providing a shared library, the original shared library and its
26298 replacement must have the same @code{SONAME} and be binary-compatible.
26300 The @option{--no-grafts} command-line option allows you to forcefully
26301 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
26305 guix build bash --no-grafts
26309 returns the store file name of the original Bash, whereas:
26316 returns the store file name of the ``fixed'', replacement Bash. This
26317 allows you to distinguish between the two variants of Bash.
26319 To verify which Bash your whole profile refers to, you can run
26320 (@pxref{Invoking guix gc}):
26323 guix gc -R `readlink -f ~/.guix-profile` | grep bash
26327 @dots{} and compare the store file names that you get with those above.
26328 Likewise for a complete Guix system generation:
26331 guix gc -R `guix system build my-config.scm` | grep bash
26334 Lastly, to check which Bash running processes are using, you can use the
26335 @command{lsof} command:
26338 lsof | grep /gnu/store/.*bash
26342 @node Bootstrapping
26343 @chapter Bootstrapping
26345 @c Adapted from the ELS 2013 paper.
26347 @cindex bootstrapping
26349 Bootstrapping in our context refers to how the distribution gets built
26350 ``from nothing''. Remember that the build environment of a derivation
26351 contains nothing but its declared inputs (@pxref{Introduction}). So
26352 there's an obvious chicken-and-egg problem: how does the first package
26353 get built? How does the first compiler get compiled? Note that this is
26354 a question of interest only to the curious hacker, not to the regular
26355 user, so you can shamelessly skip this section if you consider yourself
26356 a ``regular user''.
26358 @cindex bootstrap binaries
26359 The GNU system is primarily made of C code, with libc at its core. The
26360 GNU build system itself assumes the availability of a Bourne shell and
26361 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
26362 `grep'. Furthermore, build programs---programs that run
26363 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
26364 (@pxref{Derivations}). Consequently, to be able to build anything at
26365 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
26366 Binutils, libc, and the other packages mentioned above---the
26367 @dfn{bootstrap binaries}.
26369 These bootstrap binaries are ``taken for granted'', though we can also
26370 re-create them if needed (more on that later).
26372 @unnumberedsec Preparing to Use the Bootstrap Binaries
26374 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
26375 @c large image, it's hard to scroll. Oh well.
26376 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
26378 The figure above shows the very beginning of the dependency graph of the
26379 distribution, corresponding to the package definitions of the @code{(gnu
26380 packages bootstrap)} module. A similar figure can be generated with
26381 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
26384 guix graph -t derivation \
26385 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
26389 At this level of detail, things are
26390 slightly complex. First, Guile itself consists of an ELF executable,
26391 along with many source and compiled Scheme files that are dynamically
26392 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
26393 tarball shown in this graph. This tarball is part of Guix's ``source''
26394 distribution, and gets inserted into the store with @code{add-to-store}
26395 (@pxref{The Store}).
26397 But how do we write a derivation that unpacks this tarball and adds it
26398 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
26399 derivation---the first one that gets built---uses @code{bash} as its
26400 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
26401 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
26402 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
26403 the Guix source distribution, whose sole purpose is to allow the Guile
26404 tarball to be unpacked.
26406 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
26407 Guile that can be used to run subsequent build programs. Its first task
26408 is to download tarballs containing the other pre-built binaries---this
26409 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
26410 @code{ftp-client.scm} are used for this purpose. The
26411 @code{module-import.drv} derivations import those modules in a directory
26412 in the store, using the original layout. The
26413 @code{module-import-compiled.drv} derivations compile those modules, and
26414 write them in an output directory with the right layout. This
26415 corresponds to the @code{#:modules} argument of
26416 @code{build-expression->derivation} (@pxref{Derivations}).
26418 Finally, the various tarballs are unpacked by the
26419 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
26420 etc., at which point we have a working C tool chain.
26423 @unnumberedsec Building the Build Tools
26425 Bootstrapping is complete when we have a full tool chain that does not
26426 depend on the pre-built bootstrap tools discussed above. This
26427 no-dependency requirement is verified by checking whether the files of
26428 the final tool chain contain references to the @file{/gnu/store}
26429 directories of the bootstrap inputs. The process that leads to this
26430 ``final'' tool chain is described by the package definitions found in
26431 the @code{(gnu packages commencement)} module.
26433 The @command{guix graph} command allows us to ``zoom out'' compared to
26434 the graph above, by looking at the level of package objects instead of
26435 individual derivations---remember that a package may translate to
26436 several derivations, typically one derivation to download its source,
26437 one to build the Guile modules it needs, and one to actually build the
26438 package from source. The command:
26441 guix graph -t bag \
26442 -e '(@@@@ (gnu packages commencement)
26443 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
26447 produces the dependency graph leading to the ``final'' C
26448 library@footnote{You may notice the @code{glibc-intermediate} label,
26449 suggesting that it is not @emph{quite} final, but as a good
26450 approximation, we will consider it final.}, depicted below.
26452 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
26454 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
26455 The first tool that gets built with the bootstrap binaries is
26456 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
26457 for all the following packages. From there Findutils and Diffutils get
26460 Then come the first-stage Binutils and GCC, built as pseudo cross
26461 tools---i.e., with @code{--target} equal to @code{--host}. They are
26462 used to build libc. Thanks to this cross-build trick, this libc is
26463 guaranteed not to hold any reference to the initial tool chain.
26465 From there the final Binutils and GCC (not shown above) are built.
26467 from the final Binutils, and links programs against the just-built libc.
26468 This tool chain is used to build the other packages used by Guix and by
26469 the GNU Build System: Guile, Bash, Coreutils, etc.
26471 And voilà! At this point we have the complete set of build tools that
26472 the GNU Build System expects. These are in the @code{%final-inputs}
26473 variable of the @code{(gnu packages commencement)} module, and are
26474 implicitly used by any package that uses @code{gnu-build-system}
26475 (@pxref{Build Systems, @code{gnu-build-system}}).
26478 @unnumberedsec Building the Bootstrap Binaries
26480 @cindex bootstrap binaries
26481 Because the final tool chain does not depend on the bootstrap binaries,
26482 those rarely need to be updated. Nevertheless, it is useful to have an
26483 automated way to produce them, should an update occur, and this is what
26484 the @code{(gnu packages make-bootstrap)} module provides.
26486 The following command builds the tarballs containing the bootstrap
26487 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
26488 of Coreutils and other basic command-line tools):
26491 guix build bootstrap-tarballs
26494 The generated tarballs are those that should be referred to in the
26495 @code{(gnu packages bootstrap)} module mentioned at the beginning of
26498 Still here? Then perhaps by now you've started to wonder: when do we
26499 reach a fixed point? That is an interesting question! The answer is
26500 unknown, but if you would like to investigate further (and have
26501 significant computational and storage resources to do so), then let us
26504 @unnumberedsec Reducing the Set of Bootstrap Binaries
26506 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
26507 of binary code! Why is that a problem? It's a problem because these
26508 big chunks of binary code are practically non-auditable, which makes it
26509 hard to establish what source code produced them. Every unauditable
26510 binary also leaves us vulnerable to compiler backdoors as described by
26511 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
26513 This is mitigated by the fact that our bootstrap binaries were generated
26514 from an earlier Guix revision. Nevertheless it lacks the level of
26515 transparency that we get in the rest of the package dependency graph,
26516 where Guix always gives us a source-to-binary mapping. Thus, our goal
26517 is to reduce the set of bootstrap binaries to the bare minimum.
26519 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
26520 on-going projects to do that. One of these is about replacing the
26521 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
26522 of increasing complexity, which could be built from source starting from
26523 a simple and auditable assembler. Your help is welcome!
26527 @chapter Porting to a New Platform
26529 As discussed above, the GNU distribution is self-contained, and
26530 self-containment is achieved by relying on pre-built ``bootstrap
26531 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
26532 operating system kernel, CPU architecture, and application binary
26533 interface (ABI). Thus, to port the distribution to a platform that is
26534 not yet supported, one must build those bootstrap binaries, and update
26535 the @code{(gnu packages bootstrap)} module to use them on that platform.
26537 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
26538 When everything goes well, and assuming the GNU tool chain supports the
26539 target platform, this can be as simple as running a command like this
26543 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
26546 For this to work, the @code{glibc-dynamic-linker} procedure in
26547 @code{(gnu packages bootstrap)} must be augmented to return the right
26548 file name for libc's dynamic linker on that platform; likewise,
26549 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
26550 taught about the new platform.
26552 Once these are built, the @code{(gnu packages bootstrap)} module needs
26553 to be updated to refer to these binaries on the target platform. That
26554 is, the hashes and URLs of the bootstrap tarballs for the new platform
26555 must be added alongside those of the currently supported platforms. The
26556 bootstrap Guile tarball is treated specially: it is expected to be
26557 available locally, and @file{gnu/local.mk} has rules to download it for
26558 the supported architectures; a rule for the new platform must be added
26561 In practice, there may be some complications. First, it may be that the
26562 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
26563 above) is not recognized by all the GNU tools. Typically, glibc
26564 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
26565 configure flag (see @code{gcc.scm} for examples of how to handle this).
26566 Second, some of the required packages could fail to build for that
26567 platform. Lastly, the generated binaries could be broken for some
26570 @c *********************************************************************
26571 @include contributing.texi
26573 @c *********************************************************************
26574 @node Acknowledgments
26575 @chapter Acknowledgments
26577 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
26578 which was designed and
26579 implemented by Eelco Dolstra, with contributions from other people (see
26580 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
26581 management, and promoted unprecedented features, such as transactional
26582 package upgrades and rollbacks, per-user profiles, and referentially
26583 transparent build processes. Without this work, Guix would not exist.
26585 The Nix-based software distributions, Nixpkgs and NixOS, have also been
26586 an inspiration for Guix.
26588 GNU@tie{}Guix itself is a collective work with contributions from a
26589 number of people. See the @file{AUTHORS} file in Guix for more
26590 information on these fine people. The @file{THANKS} file lists people
26591 who have helped by reporting bugs, taking care of the infrastructure,
26592 providing artwork and themes, making suggestions, and more---thank you!
26595 @c *********************************************************************
26596 @node GNU Free Documentation License
26597 @appendix GNU Free Documentation License
26598 @cindex license, GNU Free Documentation License
26599 @include fdl-1.3.texi
26601 @c *********************************************************************
26602 @node Concept Index
26603 @unnumbered Concept Index
26606 @node Programming Index
26607 @unnumbered Programming Index
26608 @syncodeindex tp fn
26609 @syncodeindex vr fn
26614 @c Local Variables:
26615 @c ispell-local-dictionary: "american";