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 OPENPGP-SIGNING-KEY-URL https://sv.gnu.org/people/viewgpg.php?user_id=15145
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, 2019 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, 2019 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019 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@*
68 Copyright @copyright{} 2019 Jakob L. Kreuze@*
69 Copyright @copyright{} 2019 Kyle Andrews@*
70 Copyright @copyright{} 2019 Alex Griffin@*
71 Copyright @copyright{} 2019 Guillaume Le Vaillant@*
73 Permission is granted to copy, distribute and/or modify this document
74 under the terms of the GNU Free Documentation License, Version 1.3 or
75 any later version published by the Free Software Foundation; with no
76 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
77 copy of the license is included in the section entitled ``GNU Free
78 Documentation License''.
81 @dircategory System administration
83 * Guix: (guix). Manage installed software and system configuration.
84 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
85 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
86 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
87 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
88 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
91 @dircategory Software development
93 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
94 * guix build: (guix)Invoking guix build. Building packages.
95 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
99 @title GNU Guix Reference Manual
100 @subtitle Using the GNU Guix Functional Package Manager
101 @author The GNU Guix Developers
104 @vskip 0pt plus 1filll
105 Edition @value{EDITION} @*
113 @c *********************************************************************
117 This document describes GNU Guix version @value{VERSION}, a functional
118 package management tool written for the GNU system.
120 @c TRANSLATORS: You can replace the following paragraph with information on
121 @c how to join your own translation team and how to report issues with the
123 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
124 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
125 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
126 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
127 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
128 would like to translate it in your native language, consider joining the
129 @uref{https://translationproject.org/domain/guix-manual.html, Translation
133 * Introduction:: What is Guix about?
134 * Installation:: Installing Guix.
135 * System Installation:: Installing the whole operating system.
136 * Package Management:: Package installation, upgrade, etc.
137 * Development:: Guix-aided software development.
138 * Programming Interface:: Using Guix in Scheme.
139 * Utilities:: Package management commands.
140 * System Configuration:: Configuring the operating system.
141 * Documentation:: Browsing software user manuals.
142 * Installing Debugging Files:: Feeding the debugger.
143 * Security Updates:: Deploying security fixes quickly.
144 * Bootstrapping:: GNU/Linux built from scratch.
145 * Porting:: Targeting another platform or kernel.
146 * Contributing:: Your help needed!
148 * Acknowledgments:: Thanks!
149 * GNU Free Documentation License:: The license of this manual.
150 * Concept Index:: Concepts.
151 * Programming Index:: Data types, functions, and variables.
154 --- The Detailed Node Listing ---
158 * Managing Software the Guix Way:: What's special.
159 * GNU Distribution:: The packages and tools.
163 * Binary Installation:: Getting Guix running in no time!
164 * Requirements:: Software needed to build and run Guix.
165 * Running the Test Suite:: Testing Guix.
166 * Setting Up the Daemon:: Preparing the build daemon's environment.
167 * Invoking guix-daemon:: Running the build daemon.
168 * Application Setup:: Application-specific setup.
170 Setting Up the Daemon
172 * Build Environment Setup:: Preparing the isolated build environment.
173 * Daemon Offload Setup:: Offloading builds to remote machines.
174 * SELinux Support:: Using an SELinux policy for the daemon.
178 * Limitations:: What you can expect.
179 * Hardware Considerations:: Supported hardware.
180 * USB Stick and DVD Installation:: Preparing the installation medium.
181 * Preparing for Installation:: Networking, partitioning, etc.
182 * Guided Graphical Installation:: Easy graphical installation.
183 * Manual Installation:: Manual installation for wizards.
184 * After System Installation:: When installation succeeded.
185 * Installing Guix in a VM:: Guix System playground.
186 * Building the Installation Image:: How this comes to be.
190 * Keyboard Layout and Networking and Partitioning:: Initial setup.
191 * Proceeding with the Installation:: Installing.
195 * Features:: How Guix will make your life brighter.
196 * Invoking guix package:: Package installation, removal, etc.
197 * Substitutes:: Downloading pre-built binaries.
198 * Packages with Multiple Outputs:: Single source package, multiple outputs.
199 * Invoking guix gc:: Running the garbage collector.
200 * Invoking guix pull:: Fetching the latest Guix and distribution.
201 * Channels:: Customizing the package collection.
202 * Invoking guix time-machine:: Running an older revision of Guix.
203 * Inferiors:: Interacting with another revision of Guix.
204 * Invoking guix describe:: Display information about your Guix revision.
205 * Invoking guix archive:: Exporting and importing store files.
209 * Official Substitute Server:: One particular source of substitutes.
210 * Substitute Server Authorization:: How to enable or disable substitutes.
211 * Substitute Authentication:: How Guix verifies substitutes.
212 * Proxy Settings:: How to get substitutes via proxy.
213 * Substitution Failure:: What happens when substitution fails.
214 * On Trusting Binaries:: How can you trust that binary blob?
218 * Invoking guix environment:: Setting up development environments.
219 * Invoking guix pack:: Creating software bundles.
221 Programming Interface
223 * Package Modules:: Packages from the programmer's viewpoint.
224 * Defining Packages:: Defining new packages.
225 * Build Systems:: Specifying how packages are built.
226 * The Store:: Manipulating the package store.
227 * Derivations:: Low-level interface to package derivations.
228 * The Store Monad:: Purely functional interface to the store.
229 * G-Expressions:: Manipulating build expressions.
230 * Invoking guix repl:: Fiddling with Guix interactively.
234 * package Reference:: The package data type.
235 * origin Reference:: The origin data type.
239 * Invoking guix build:: Building packages from the command line.
240 * Invoking guix edit:: Editing package definitions.
241 * Invoking guix download:: Downloading a file and printing its hash.
242 * Invoking guix hash:: Computing the cryptographic hash of a file.
243 * Invoking guix import:: Importing package definitions.
244 * Invoking guix refresh:: Updating package definitions.
245 * Invoking guix lint:: Finding errors in package definitions.
246 * Invoking guix size:: Profiling disk usage.
247 * Invoking guix graph:: Visualizing the graph of packages.
248 * Invoking guix publish:: Sharing substitutes.
249 * Invoking guix challenge:: Challenging substitute servers.
250 * Invoking guix copy:: Copying to and from a remote store.
251 * Invoking guix container:: Process isolation.
252 * Invoking guix weather:: Assessing substitute availability.
253 * Invoking guix processes:: Listing client processes.
255 Invoking @command{guix build}
257 * Common Build Options:: Build options for most commands.
258 * Package Transformation Options:: Creating variants of packages.
259 * Additional Build Options:: Options specific to 'guix build'.
260 * Debugging Build Failures:: Real life packaging experience.
264 * Using the Configuration System:: Customizing your GNU system.
265 * operating-system Reference:: Detail of operating-system declarations.
266 * File Systems:: Configuring file system mounts.
267 * Mapped Devices:: Block device extra processing.
268 * User Accounts:: Specifying user accounts.
269 * Keyboard Layout:: How the system interprets key strokes.
270 * Locales:: Language and cultural convention settings.
271 * Services:: Specifying system services.
272 * Setuid Programs:: Programs running with root privileges.
273 * X.509 Certificates:: Authenticating HTTPS servers.
274 * Name Service Switch:: Configuring libc's name service switch.
275 * Initial RAM Disk:: Linux-Libre bootstrapping.
276 * Bootloader Configuration:: Configuring the boot loader.
277 * Invoking guix system:: Instantiating a system configuration.
278 * Invoking guix deploy:: Deploying a system configuration to a remote host.
279 * Running Guix in a VM:: How to run Guix System in a virtual machine.
280 * Defining Services:: Adding new service definitions.
284 * Base Services:: Essential system services.
285 * Scheduled Job Execution:: The mcron service.
286 * Log Rotation:: The rottlog service.
287 * Networking Services:: Network setup, SSH daemon, etc.
288 * X Window:: Graphical display.
289 * Printing Services:: Local and remote printer support.
290 * Desktop Services:: D-Bus and desktop services.
291 * Sound Services:: ALSA and Pulseaudio services.
292 * Database Services:: SQL databases, key-value stores, etc.
293 * Mail Services:: IMAP, POP3, SMTP, and all that.
294 * Messaging Services:: Messaging services.
295 * Telephony Services:: Telephony services.
296 * Monitoring Services:: Monitoring services.
297 * Kerberos Services:: Kerberos services.
298 * Web Services:: Web servers.
299 * Certificate Services:: TLS certificates via Let's Encrypt.
300 * DNS Services:: DNS daemons.
301 * VPN Services:: VPN daemons.
302 * Network File System:: NFS related services.
303 * Continuous Integration:: The Cuirass service.
304 * Power Management Services:: Extending battery life.
305 * Audio Services:: The MPD.
306 * Virtualization Services:: Virtualization services.
307 * Version Control Services:: Providing remote access to Git repositories.
308 * Game Services:: Game servers.
309 * PAM Mount Service:: Service to mount volumes when logging in.
310 * Miscellaneous Services:: Other services.
314 * Service Composition:: The model for composing services.
315 * Service Types and Services:: Types and services.
316 * Service Reference:: API reference.
317 * Shepherd Services:: A particular type of service.
322 @c *********************************************************************
324 @chapter Introduction
327 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
328 using the international phonetic alphabet (IPA).} is a package
329 management tool for and distribution of the GNU system.
330 Guix makes it easy for unprivileged
331 users to install, upgrade, or remove software packages, to roll back to a
332 previous package set, to build packages from source, and generally
333 assists with the creation and maintenance of software environments.
336 @cindex GuixSD, now Guix System
337 @cindex Guix System Distribution, now Guix System
338 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
339 complements the available tools without interference (@pxref{Installation}),
340 or you can use it as a standalone operating system distribution,
341 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
342 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
343 group everything under the ``Guix'' banner since, after all, Guix System is
344 readily available through the @command{guix system} command, even if you're
345 using a different distro underneath!}. @xref{GNU Distribution}.
348 * Managing Software the Guix Way:: What's special.
349 * GNU Distribution:: The packages and tools.
352 @node Managing Software the Guix Way
353 @section Managing Software the Guix Way
355 @cindex user interfaces
356 Guix provides a command-line package management interface
357 (@pxref{Package Management}), tools to help with software development
358 (@pxref{Development}), command-line utilities for more advanced usage,
359 (@pxref{Utilities}), as well as Scheme programming interfaces
360 (@pxref{Programming Interface}).
362 Its @dfn{build daemon} is responsible for building packages on behalf of
363 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
364 binaries from authorized sources (@pxref{Substitutes}).
366 @cindex extensibility of the distribution
367 @cindex customization, of packages
368 Guix includes package definitions for many GNU and non-GNU packages, all
369 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
370 user's computing freedom}. It is @emph{extensible}: users can write
371 their own package definitions (@pxref{Defining Packages}) and make them
372 available as independent package modules (@pxref{Package Modules}). It
373 is also @emph{customizable}: users can @emph{derive} specialized package
374 definitions from existing ones, including from the command line
375 (@pxref{Package Transformation Options}).
377 @cindex functional package management
379 Under the hood, Guix implements the @dfn{functional package management}
380 discipline pioneered by Nix (@pxref{Acknowledgments}).
381 In Guix, the package build and installation process is seen
382 as a @emph{function}, in the mathematical sense. That function takes inputs,
383 such as build scripts, a compiler, and libraries, and
384 returns an installed package. As a pure function, its result depends
385 solely on its inputs---for instance, it cannot refer to software or
386 scripts that were not explicitly passed as inputs. A build function
387 always produces the same result when passed a given set of inputs. It
388 cannot alter the environment of the running system in
389 any way; for instance, it cannot create, modify, or delete files outside
390 of its build and installation directories. This is achieved by running
391 build processes in isolated environments (or @dfn{containers}), where only their
392 explicit inputs are visible.
395 The result of package build functions is @dfn{cached} in the file
396 system, in a special directory called @dfn{the store} (@pxref{The
397 Store}). Each package is installed in a directory of its own in the
398 store---by default under @file{/gnu/store}. The directory name contains
399 a hash of all the inputs used to build that package; thus, changing an
400 input yields a different directory name.
402 This approach is the foundation for the salient features of Guix: support
403 for transactional package upgrade and rollback, per-user installation, and
404 garbage collection of packages (@pxref{Features}).
407 @node GNU Distribution
408 @section GNU Distribution
411 Guix comes with a distribution of the GNU system consisting entirely of
412 free software@footnote{The term ``free'' here refers to the
413 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
414 users of that software}.}. The
415 distribution can be installed on its own (@pxref{System Installation}),
416 but it is also possible to install Guix as a package manager on top of
417 an installed GNU/Linux system (@pxref{Installation}). When we need to
418 distinguish between the two, we refer to the standalone distribution as
421 The distribution provides core GNU packages such as GNU libc, GCC, and
422 Binutils, as well as many GNU and non-GNU applications. The complete
423 list of available packages can be browsed
424 @url{https://www.gnu.org/software/guix/packages,on-line} or by
425 running @command{guix package} (@pxref{Invoking guix package}):
428 guix package --list-available
431 Our goal is to provide a practical 100% free software distribution of
432 Linux-based and other variants of GNU, with a focus on the promotion and
433 tight integration of GNU components, and an emphasis on programs and
434 tools that help users exert that freedom.
436 Packages are currently available on the following platforms:
441 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
444 Intel 32-bit architecture (IA32), Linux-Libre kernel;
447 ARMv7-A architecture with hard float, Thumb-2 and NEON,
448 using the EABI hard-float application binary interface (ABI),
449 and Linux-Libre kernel.
452 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
455 little-endian 64-bit MIPS processors, specifically the Loongson series,
456 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
457 supported; in particular, the project's build farms no longer provide
458 substitutes for this architecture.
462 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
463 configuration and Guix takes care of instantiating the configuration in a
464 transactional, reproducible, and stateless fashion (@pxref{System
465 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
466 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
467 Manual}), the well-known GNU utilities and tool chain, as well as the
468 graphical environment or system services of your choice.
470 Guix System is available on all the above platforms except
471 @code{mips64el-linux}.
474 For information on porting to other architectures or kernels,
477 Building this distribution is a cooperative effort, and you are invited
478 to join! @xref{Contributing}, for information about how you can help.
481 @c *********************************************************************
483 @chapter Installation
485 @cindex installing Guix
488 We recommend the use of this
489 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
490 shell installer script} to install Guix on top of a running GNU/Linux system,
491 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
492 with the installation of the package manager, which can be done on top of a
493 running GNU/Linux system. If, instead, you want to install the complete GNU
494 operating system, @pxref{System Installation}.} The script automates the
495 download, installation, and initial configuration of Guix. It should be run
499 @cindex foreign distro
500 @cindex directories related to foreign distro
501 When installed on a foreign distro, GNU@tie{}Guix complements the available
502 tools without interference. Its data lives exclusively in two directories,
503 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
504 such as @file{/etc}, are left untouched.
506 Once installed, Guix can be updated by running @command{guix pull}
507 (@pxref{Invoking guix pull}).
509 If you prefer to perform the installation steps manually or want to tweak
510 them, you may find the following subsections useful. They describe the
511 software requirements of Guix, as well as how to install it manually and get
515 * Binary Installation:: Getting Guix running in no time!
516 * Requirements:: Software needed to build and run Guix.
517 * Running the Test Suite:: Testing Guix.
518 * Setting Up the Daemon:: Preparing the build daemon's environment.
519 * Invoking guix-daemon:: Running the build daemon.
520 * Application Setup:: Application-specific setup.
521 * Upgrading Guix:: Upgrading Guix and its build daemon.
524 @node Binary Installation
525 @section Binary Installation
527 @cindex installing Guix from binaries
528 @cindex installer script
529 This section describes how to install Guix on an arbitrary system from a
530 self-contained tarball providing binaries for Guix and for all its
531 dependencies. This is often quicker than installing from source, which
532 is described in the next sections. The only requirement is to have
535 @c Note duplicated from the ``Installation'' node.
537 We recommend the use of this
538 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
539 shell installer script}. The script automates the download, installation, and
540 initial configuration steps described below. It should be run as the root
544 Installing goes along these lines:
548 @cindex downloading Guix binary
549 Download the binary tarball from
550 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
551 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
552 already running the kernel Linux, and so on.
554 @c The following is somewhat duplicated in ``System Installation''.
555 Make sure to download the associated @file{.sig} file and to verify the
556 authenticity of the tarball against it, along these lines:
559 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
560 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
563 If that command fails because you do not have the required public key,
564 then run this command to import it:
567 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
568 -qO - | gpg --import -
572 and rerun the @code{gpg --verify} command.
574 Take note that a warning like ``This key is not certified with a trusted
575 signature!'' is normal.
577 @c end authentication part
580 Now, you need to become the @code{root} user. Depending on your distribution,
581 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
585 # tar --warning=no-timestamp -xf \
586 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
587 # mv var/guix /var/ && mv gnu /
590 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
591 The latter contains a ready-to-use profile for @code{root} (see next
594 Do @emph{not} unpack the tarball on a working Guix system since that
595 would overwrite its own essential files.
597 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
598 not emit warnings about ``implausibly old time stamps'' (such
599 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
601 They stem from the fact that all the
602 files in the archive have their modification time set to zero (which
603 means January 1st, 1970.) This is done on purpose to make sure the
604 archive content is independent of its creation time, thus making it
608 Make the profile available under @file{~root/.config/guix/current}, which is
609 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
612 # mkdir -p ~root/.config/guix
613 # ln -sf /var/guix/profiles/per-user/root/current-guix \
614 ~root/.config/guix/current
617 Source @file{etc/profile} to augment @code{PATH} and other relevant
618 environment variables:
621 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
622 source $GUIX_PROFILE/etc/profile
626 Create the group and user accounts for build users as explained below
627 (@pxref{Build Environment Setup}).
630 Run the daemon, and set it to automatically start on boot.
632 If your host distro uses the systemd init system, this can be achieved
635 @c Versions of systemd that supported symlinked service files are not
636 @c yet widely deployed, so we should suggest that users copy the service
639 @c See this thread for more information:
640 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
643 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
645 # systemctl start guix-daemon && systemctl enable guix-daemon
648 If your host distro uses the Upstart init system:
651 # initctl reload-configuration
652 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
657 Otherwise, you can still start the daemon manually with:
660 # ~root/.config/guix/current/bin/guix-daemon \
661 --build-users-group=guixbuild
665 Make the @command{guix} command available to other users on the machine,
669 # mkdir -p /usr/local/bin
671 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
674 It is also a good idea to make the Info version of this manual available
678 # mkdir -p /usr/local/share/info
679 # cd /usr/local/share/info
680 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
684 That way, assuming @file{/usr/local/share/info} is in the search path,
685 running @command{info guix} will open this manual (@pxref{Other Info
686 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
690 @cindex substitutes, authorization thereof
691 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
692 (@pxref{Substitutes}), authorize them:
695 # guix archive --authorize < \
696 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
700 Each user may need to perform a few additional steps to make their Guix
701 environment ready for use, @pxref{Application Setup}.
704 Voilà, the installation is complete!
706 You can confirm that Guix is working by installing a sample package into
713 The binary installation tarball can be (re)produced and verified simply
714 by running the following command in the Guix source tree:
717 make guix-binary.@var{system}.tar.xz
721 ...@: which, in turn, runs:
724 guix pack -s @var{system} --localstatedir \
725 --profile-name=current-guix guix
728 @xref{Invoking guix pack}, for more info on this handy tool.
731 @section Requirements
733 This section lists requirements when building Guix from source. The
734 build procedure for Guix is the same as for other GNU software, and is
735 not covered here. Please see the files @file{README} and @file{INSTALL}
736 in the Guix source tree for additional details.
738 @cindex official website
739 GNU Guix is available for download from its website at
740 @url{https://www.gnu.org/software/guix/}.
742 GNU Guix depends on the following packages:
745 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
746 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
749 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
750 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
751 Guile,, gnutls-guile, GnuTLS-Guile});
753 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
756 @c FIXME: Specify a version number once a release has been made.
757 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
759 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
760 @item @url{https://zlib.net, zlib};
761 @item @url{https://www.gnu.org/software/make/, GNU Make}.
764 The following dependencies are optional:
768 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
769 Support for build offloading (@pxref{Daemon Offload Setup}) and
770 @command{guix copy} (@pxref{Invoking guix copy}) depends on
771 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
772 version 0.10.2 or later.
775 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
776 substitutes can be used and @command{guix publish} can compress substitutes
780 When @url{http://www.bzip.org, libbz2} is available,
781 @command{guix-daemon} can use it to compress build logs.
784 Unless @code{--disable-daemon} was passed to @command{configure}, the
785 following packages are also needed:
788 @item @url{https://gnupg.org/, GNU libgcrypt};
789 @item @url{https://sqlite.org, SQLite 3};
790 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
794 @cindex state directory
795 When configuring Guix on a system that already has a Guix installation,
796 be sure to specify the same state directory as the existing installation
797 using the @code{--localstatedir} option of the @command{configure}
798 script (@pxref{Directory Variables, @code{localstatedir},, standards,
799 GNU Coding Standards}). Usually, this @var{localstatedir} option is
800 set to the value @file{/var}. The @command{configure} script protects
801 against unintended misconfiguration of @var{localstatedir} so you do not
802 inadvertently corrupt your store (@pxref{The Store}).
804 @node Running the Test Suite
805 @section Running the Test Suite
808 After a successful @command{configure} and @code{make} run, it is a good
809 idea to run the test suite. It can help catch issues with the setup or
810 environment, or bugs in Guix itself---and really, reporting test
811 failures is a good way to help improve the software. To run the test
818 Test cases can run in parallel: you can use the @code{-j} option of
819 GNU@tie{}make to speed things up. The first run may take a few minutes
820 on a recent machine; subsequent runs will be faster because the store
821 that is created for test purposes will already have various things in
824 It is also possible to run a subset of the tests by defining the
825 @code{TESTS} makefile variable as in this example:
828 make check TESTS="tests/store.scm tests/cpio.scm"
831 By default, tests results are displayed at a file level. In order to
832 see the details of every individual test cases, it is possible to define
833 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
836 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
839 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
840 @file{test-suite.log} file. Please specify the Guix version being used
841 as well as version numbers of the dependencies (@pxref{Requirements}) in
844 Guix also comes with a whole-system test suite that tests complete
845 Guix System instances. It can only run on systems where
846 Guix is already installed, using:
853 or, again, by defining @code{TESTS} to select a subset of tests to run:
856 make check-system TESTS="basic mcron"
859 These system tests are defined in the @code{(gnu tests @dots{})}
860 modules. They work by running the operating systems under test with
861 lightweight instrumentation in a virtual machine (VM). They can be
862 computationally intensive or rather cheap, depending on whether
863 substitutes are available for their dependencies (@pxref{Substitutes}).
864 Some of them require a lot of storage space to hold VM images.
866 Again in case of test failures, please send @email{bug-guix@@gnu.org}
869 @node Setting Up the Daemon
870 @section Setting Up the Daemon
873 Operations such as building a package or running the garbage collector
874 are all performed by a specialized process, the @dfn{build daemon}, on
875 behalf of clients. Only the daemon may access the store and its
876 associated database. Thus, any operation that manipulates the store
877 goes through the daemon. For instance, command-line tools such as
878 @command{guix package} and @command{guix build} communicate with the
879 daemon (@i{via} remote procedure calls) to instruct it what to do.
881 The following sections explain how to prepare the build daemon's
882 environment. See also @ref{Substitutes}, for information on how to allow
883 the daemon to download pre-built binaries.
886 * Build Environment Setup:: Preparing the isolated build environment.
887 * Daemon Offload Setup:: Offloading builds to remote machines.
888 * SELinux Support:: Using an SELinux policy for the daemon.
891 @node Build Environment Setup
892 @subsection Build Environment Setup
894 @cindex build environment
895 In a standard multi-user setup, Guix and its daemon---the
896 @command{guix-daemon} program---are installed by the system
897 administrator; @file{/gnu/store} is owned by @code{root} and
898 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
899 Guix tools to build packages or otherwise access the store, and the
900 daemon will do it on their behalf, ensuring that the store is kept in a
901 consistent state, and allowing built packages to be shared among users.
904 When @command{guix-daemon} runs as @code{root}, you may not want package
905 build processes themselves to run as @code{root} too, for obvious
906 security reasons. To avoid that, a special pool of @dfn{build users}
907 should be created for use by build processes started by the daemon.
908 These build users need not have a shell and a home directory: they will
909 just be used when the daemon drops @code{root} privileges in build
910 processes. Having several such users allows the daemon to launch
911 distinct build processes under separate UIDs, which guarantees that they
912 do not interfere with each other---an essential feature since builds are
913 regarded as pure functions (@pxref{Introduction}).
915 On a GNU/Linux system, a build user pool may be created like this (using
916 Bash syntax and the @code{shadow} commands):
918 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
919 @c for why `-G' is needed.
921 # groupadd --system guixbuild
922 # for i in `seq -w 1 10`;
924 useradd -g guixbuild -G guixbuild \
925 -d /var/empty -s `which nologin` \
926 -c "Guix build user $i" --system \
932 The number of build users determines how many build jobs may run in
933 parallel, as specified by the @option{--max-jobs} option
934 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
935 @command{guix system vm} and related commands, you may need to add the
936 build users to the @code{kvm} group so they can access @file{/dev/kvm},
937 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
938 (@pxref{Invoking guix system}).
940 The @code{guix-daemon} program may then be run as @code{root} with the
941 following command@footnote{If your machine uses the systemd init system,
942 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
943 file in @file{/etc/systemd/system} will ensure that
944 @command{guix-daemon} is automatically started. Similarly, if your
945 machine uses the Upstart init system, drop the
946 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
947 file in @file{/etc/init}.}:
950 # guix-daemon --build-users-group=guixbuild
955 This way, the daemon starts build processes in a chroot, under one of
956 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
957 environment contains nothing but:
959 @c Keep this list in sync with libstore/build.cc! -----------------------
962 a minimal @code{/dev} directory, created mostly independently from the
963 host @code{/dev}@footnote{``Mostly'', because while the set of files
964 that appear in the chroot's @code{/dev} is fixed, most of these files
965 can only be created if the host has them.};
968 the @code{/proc} directory; it only shows the processes of the container
969 since a separate PID name space is used;
972 @file{/etc/passwd} with an entry for the current user and an entry for
976 @file{/etc/group} with an entry for the user's group;
979 @file{/etc/hosts} with an entry that maps @code{localhost} to
983 a writable @file{/tmp} directory.
986 You can influence the directory where the daemon stores build trees
987 @i{via} the @code{TMPDIR} environment variable. However, the build tree
988 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
989 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
990 This way, the value of @code{TMPDIR} does not leak inside build
991 environments, which avoids discrepancies in cases where build processes
992 capture the name of their build tree.
995 The daemon also honors the @code{http_proxy} environment variable for
996 HTTP downloads it performs, be it for fixed-output derivations
997 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
999 If you are installing Guix as an unprivileged user, it is still possible
1000 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
1001 However, build processes will not be isolated from one another, and not
1002 from the rest of the system. Thus, build processes may interfere with
1003 each other, and may access programs, libraries, and other files
1004 available on the system---making it much harder to view them as
1005 @emph{pure} functions.
1008 @node Daemon Offload Setup
1009 @subsection Using the Offload Facility
1013 When desired, the build daemon can @dfn{offload} derivation builds to
1014 other machines running Guix, using the @code{offload} @dfn{build
1015 hook}@footnote{This feature is available only when
1016 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1017 present.}. When that
1018 feature is enabled, a list of user-specified build machines is read from
1019 @file{/etc/guix/machines.scm}; every time a build is requested, for
1020 instance via @code{guix build}, the daemon attempts to offload it to one
1021 of the machines that satisfy the constraints of the derivation, in
1022 particular its system type---e.g., @file{x86_64-linux}. Missing
1023 prerequisites for the build are copied over SSH to the target machine,
1024 which then proceeds with the build; upon success the output(s) of the
1025 build are copied back to the initial machine.
1027 The @file{/etc/guix/machines.scm} file typically looks like this:
1030 (list (build-machine
1031 (name "eightysix.example.org")
1032 (system "x86_64-linux")
1033 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1035 (speed 2.)) ;incredibly fast!
1038 (name "meeps.example.org")
1039 (system "mips64el-linux")
1040 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1043 (string-append (getenv "HOME")
1044 "/.ssh/identity-for-guix"))))
1048 In the example above we specify a list of two build machines, one for
1049 the @code{x86_64} architecture and one for the @code{mips64el}
1052 In fact, this file is---not surprisingly!---a Scheme file that is
1053 evaluated when the @code{offload} hook is started. Its return value
1054 must be a list of @code{build-machine} objects. While this example
1055 shows a fixed list of build machines, one could imagine, say, using
1056 DNS-SD to return a list of potential build machines discovered in the
1057 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1058 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1061 @deftp {Data Type} build-machine
1062 This data type represents build machines to which the daemon may offload
1063 builds. The important fields are:
1068 The host name of the remote machine.
1071 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1074 The user account to use when connecting to the remote machine over SSH.
1075 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1076 allow non-interactive logins.
1079 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1080 This is used to authenticate the machine when we connect to it. It is a
1081 long string that looks like this:
1084 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1087 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1088 key can be found in a file such as
1089 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1091 If the machine is running the SSH daemon of GNU@tie{}lsh,
1092 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1093 similar file. It can be converted to the OpenSSH format using
1094 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1097 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1098 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1103 A number of optional fields may be specified:
1107 @item @code{port} (default: @code{22})
1108 Port number of SSH server on the machine.
1110 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1111 The SSH private key file to use when connecting to the machine, in
1112 OpenSSH format. This key must not be protected with a passphrase.
1114 Note that the default value is the private key @emph{of the root
1115 account}. Make sure it exists if you use the default.
1117 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1118 @itemx @code{compression-level} (default: @code{3})
1119 The SSH-level compression methods and compression level requested.
1121 Note that offloading relies on SSH compression to reduce bandwidth usage
1122 when transferring files to and from build machines.
1124 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1125 File name of the Unix-domain socket @command{guix-daemon} is listening
1128 @item @code{parallel-builds} (default: @code{1})
1129 The number of builds that may run in parallel on the machine.
1131 @item @code{speed} (default: @code{1.0})
1132 A ``relative speed factor''. The offload scheduler will tend to prefer
1133 machines with a higher speed factor.
1135 @item @code{features} (default: @code{'()})
1136 A list of strings denoting specific features supported by the machine.
1137 An example is @code{"kvm"} for machines that have the KVM Linux modules
1138 and corresponding hardware support. Derivations can request features by
1139 name, and they will be scheduled on matching build machines.
1144 The @command{guix} command must be in the search path on the build
1145 machines. You can check whether this is the case by running:
1148 ssh build-machine guix repl --version
1151 There is one last thing to do once @file{machines.scm} is in place. As
1152 explained above, when offloading, files are transferred back and forth
1153 between the machine stores. For this to work, you first need to
1154 generate a key pair on each machine to allow the daemon to export signed
1155 archives of files from the store (@pxref{Invoking guix archive}):
1158 # guix archive --generate-key
1162 Each build machine must authorize the key of the master machine so that
1163 it accepts store items it receives from the master:
1166 # guix archive --authorize < master-public-key.txt
1170 Likewise, the master machine must authorize the key of each build machine.
1172 All the fuss with keys is here to express pairwise mutual trust
1173 relations between the master and the build machines. Concretely, when
1174 the master receives files from a build machine (and @i{vice versa}), its
1175 build daemon can make sure they are genuine, have not been tampered
1176 with, and that they are signed by an authorized key.
1178 @cindex offload test
1179 To test whether your setup is operational, run this command on the
1186 This will attempt to connect to each of the build machines specified in
1187 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1188 available on each machine, attempt to export to the machine and import
1189 from it, and report any error in the process.
1191 If you want to test a different machine file, just specify it on the
1195 # guix offload test machines-qualif.scm
1198 Last, you can test the subset of the machines whose name matches a
1199 regular expression like this:
1202 # guix offload test machines.scm '\.gnu\.org$'
1205 @cindex offload status
1206 To display the current load of all build hosts, run this command on the
1210 # guix offload status
1214 @node SELinux Support
1215 @subsection SELinux Support
1217 @cindex SELinux, daemon policy
1218 @cindex mandatory access control, SELinux
1219 @cindex security, guix-daemon
1220 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1221 can be installed on a system where SELinux is enabled, in order to label
1222 Guix files and to specify the expected behavior of the daemon. Since
1223 Guix System does not provide an SELinux base policy, the daemon policy cannot
1224 be used on Guix System.
1226 @subsubsection Installing the SELinux policy
1227 @cindex SELinux, policy installation
1228 To install the policy run this command as root:
1231 semodule -i etc/guix-daemon.cil
1234 Then relabel the file system with @code{restorecon} or by a different
1235 mechanism provided by your system.
1237 Once the policy is installed, the file system has been relabeled, and
1238 the daemon has been restarted, it should be running in the
1239 @code{guix_daemon_t} context. You can confirm this with the following
1243 ps -Zax | grep guix-daemon
1246 Monitor the SELinux log files as you run a command like @code{guix build
1247 hello} to convince yourself that SELinux permits all necessary
1250 @subsubsection Limitations
1251 @cindex SELinux, limitations
1253 This policy is not perfect. Here is a list of limitations or quirks
1254 that should be considered when deploying the provided SELinux policy for
1259 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1260 operations involve contexts that have anything to do with
1261 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1262 but it would be preferrable to define socket rules for only this label.
1265 @code{guix gc} cannot access arbitrary links to profiles. By design,
1266 the file label of the destination of a symlink is independent of the
1267 file label of the link itself. Although all profiles under
1268 $localstatedir are labelled, the links to these profiles inherit the
1269 label of the directory they are in. For links in the user’s home
1270 directory this will be @code{user_home_t}. But for links from the root
1271 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1272 directory, etc, this won’t work. @code{guix gc} would be prevented from
1273 reading and following these links.
1276 The daemon’s feature to listen for TCP connections might no longer work.
1277 This might require extra rules, because SELinux treats network sockets
1278 differently from files.
1281 Currently all files with a name matching the regular expression
1282 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1283 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1284 that name in any profile would be permitted to run in the
1285 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1286 build a package that provides this executable and convince a user to
1287 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1288 At that point SELinux could not prevent it from accessing files that are
1289 allowed for processes in that domain.
1291 We could generate a much more restrictive policy at installation time,
1292 so that only the @emph{exact} file name of the currently installed
1293 @code{guix-daemon} executable would be labelled with
1294 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1295 The downside is that root would have to install or upgrade the policy at
1296 installation time whenever the Guix package that provides the
1297 effectively running @code{guix-daemon} executable is upgraded.
1300 @node Invoking guix-daemon
1301 @section Invoking @command{guix-daemon}
1303 The @command{guix-daemon} program implements all the functionality to
1304 access the store. This includes launching build processes, running the
1305 garbage collector, querying the availability of a build result, etc. It
1306 is normally run as @code{root} like this:
1309 # guix-daemon --build-users-group=guixbuild
1313 For details on how to set it up, @pxref{Setting Up the Daemon}.
1316 @cindex container, build environment
1317 @cindex build environment
1318 @cindex reproducible builds
1319 By default, @command{guix-daemon} launches build processes under
1320 different UIDs, taken from the build group specified with
1321 @code{--build-users-group}. In addition, each build process is run in a
1322 chroot environment that only contains the subset of the store that the
1323 build process depends on, as specified by its derivation
1324 (@pxref{Programming Interface, derivation}), plus a set of specific
1325 system directories. By default, the latter contains @file{/dev} and
1326 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1327 @dfn{container}: in addition to having its own file system tree, it has
1328 a separate mount name space, its own PID name space, network name space,
1329 etc. This helps achieve reproducible builds (@pxref{Features}).
1331 When the daemon performs a build on behalf of the user, it creates a
1332 build directory under @file{/tmp} or under the directory specified by
1333 its @code{TMPDIR} environment variable. This directory is shared with
1334 the container for the duration of the build, though within the container,
1335 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1337 The build directory is automatically deleted upon completion, unless the
1338 build failed and the client specified @option{--keep-failed}
1339 (@pxref{Invoking guix build, @option{--keep-failed}}).
1341 The daemon listens for connections and spawns one sub-process for each session
1342 started by a client (one of the @command{guix} sub-commands.) The
1343 @command{guix processes} command allows you to get an overview of the activity
1344 on your system by viewing each of the active sessions and clients.
1345 @xref{Invoking guix processes}, for more information.
1347 The following command-line options are supported:
1350 @item --build-users-group=@var{group}
1351 Take users from @var{group} to run build processes (@pxref{Setting Up
1352 the Daemon, build users}).
1354 @item --no-substitutes
1356 Do not use substitutes for build products. That is, always build things
1357 locally instead of allowing downloads of pre-built binaries
1358 (@pxref{Substitutes}).
1360 When the daemon runs with @code{--no-substitutes}, clients can still
1361 explicitly enable substitution @i{via} the @code{set-build-options}
1362 remote procedure call (@pxref{The Store}).
1364 @item --substitute-urls=@var{urls}
1365 @anchor{daemon-substitute-urls}
1366 Consider @var{urls} the default whitespace-separated list of substitute
1367 source URLs. When this option is omitted,
1368 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1370 This means that substitutes may be downloaded from @var{urls}, as long
1371 as they are signed by a trusted signature (@pxref{Substitutes}).
1375 Do not use offload builds to other machines (@pxref{Daemon Offload
1376 Setup}). That is, always build things locally instead of offloading
1377 builds to remote machines.
1379 @item --cache-failures
1380 Cache build failures. By default, only successful builds are cached.
1382 When this option is used, @command{guix gc --list-failures} can be used
1383 to query the set of store items marked as failed; @command{guix gc
1384 --clear-failures} removes store items from the set of cached failures.
1385 @xref{Invoking guix gc}.
1387 @item --cores=@var{n}
1389 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1392 The default value is @code{0}, but it may be overridden by clients, such
1393 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1396 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1397 in the build process, which can then use it to exploit internal
1398 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1400 @item --max-jobs=@var{n}
1402 Allow at most @var{n} build jobs in parallel. The default value is
1403 @code{1}. Setting it to @code{0} means that no builds will be performed
1404 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1405 Setup}), or simply fail.
1407 @item --max-silent-time=@var{seconds}
1408 When the build or substitution process remains silent for more than
1409 @var{seconds}, terminate it and report a build failure.
1411 The default value is @code{0}, which disables the timeout.
1413 The value specified here can be overridden by clients (@pxref{Common
1414 Build Options, @code{--max-silent-time}}).
1416 @item --timeout=@var{seconds}
1417 Likewise, when the build or substitution process lasts for more than
1418 @var{seconds}, terminate it and report a build failure.
1420 The default value is @code{0}, which disables the timeout.
1422 The value specified here can be overridden by clients (@pxref{Common
1423 Build Options, @code{--timeout}}).
1425 @item --rounds=@var{N}
1426 Build each derivation @var{n} times in a row, and raise an error if
1427 consecutive build results are not bit-for-bit identical. Note that this
1428 setting can be overridden by clients such as @command{guix build}
1429 (@pxref{Invoking guix build}).
1431 When used in conjunction with @option{--keep-failed}, the differing
1432 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1433 This makes it easy to look for differences between the two results.
1436 Produce debugging output.
1438 This is useful to debug daemon start-up issues, but then it may be
1439 overridden by clients, for example the @code{--verbosity} option of
1440 @command{guix build} (@pxref{Invoking guix build}).
1442 @item --chroot-directory=@var{dir}
1443 Add @var{dir} to the build chroot.
1445 Doing this may change the result of build processes---for instance if
1446 they use optional dependencies found in @var{dir} when it is available,
1447 and not otherwise. For that reason, it is not recommended to do so.
1448 Instead, make sure that each derivation declares all the inputs that it
1451 @item --disable-chroot
1452 Disable chroot builds.
1454 Using this option is not recommended since, again, it would allow build
1455 processes to gain access to undeclared dependencies. It is necessary,
1456 though, when @command{guix-daemon} is running under an unprivileged user
1459 @item --log-compression=@var{type}
1460 Compress build logs according to @var{type}, one of @code{gzip},
1461 @code{bzip2}, or @code{none}.
1463 Unless @code{--lose-logs} is used, all the build logs are kept in the
1464 @var{localstatedir}. To save space, the daemon automatically compresses
1465 them with bzip2 by default.
1467 @item --disable-deduplication
1468 @cindex deduplication
1469 Disable automatic file ``deduplication'' in the store.
1471 By default, files added to the store are automatically ``deduplicated'':
1472 if a newly added file is identical to another one found in the store,
1473 the daemon makes the new file a hard link to the other file. This can
1474 noticeably reduce disk usage, at the expense of slightly increased
1475 input/output load at the end of a build process. This option disables
1478 @item --gc-keep-outputs[=yes|no]
1479 Tell whether the garbage collector (GC) must keep outputs of live
1483 @cindex garbage collector roots
1484 When set to ``yes'', the GC will keep the outputs of any live derivation
1485 available in the store---the @code{.drv} files. The default is ``no'',
1486 meaning that derivation outputs are kept only if they are reachable from a GC
1487 root. @xref{Invoking guix gc}, for more on GC roots.
1489 @item --gc-keep-derivations[=yes|no]
1490 Tell whether the garbage collector (GC) must keep derivations
1491 corresponding to live outputs.
1493 When set to ``yes'', as is the case by default, the GC keeps
1494 derivations---i.e., @code{.drv} files---as long as at least one of their
1495 outputs is live. This allows users to keep track of the origins of
1496 items in their store. Setting it to ``no'' saves a bit of disk space.
1498 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1499 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1500 ``yes'' causes liveness to flow from derivations to outputs. When both are
1501 set to ``yes'', the effect is to keep all the build prerequisites (the
1502 sources, compiler, libraries, and other build-time tools) of live objects in
1503 the store, regardless of whether these prerequisites are reachable from a GC
1504 root. This is convenient for developers since it saves rebuilds or downloads.
1506 @item --impersonate-linux-2.6
1507 On Linux-based systems, impersonate Linux 2.6. This means that the
1508 kernel's @code{uname} system call will report 2.6 as the release number.
1510 This might be helpful to build programs that (usually wrongfully) depend
1511 on the kernel version number.
1514 Do not keep build logs. By default they are kept under
1515 @code{@var{localstatedir}/guix/log}.
1517 @item --system=@var{system}
1518 Assume @var{system} as the current system type. By default it is the
1519 architecture/kernel pair found at configure time, such as
1520 @code{x86_64-linux}.
1522 @item --listen=@var{endpoint}
1523 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1524 as the file name of a Unix-domain socket if it starts with
1525 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1526 host name or host name and port to listen to. Here are a few examples:
1529 @item --listen=/gnu/var/daemon
1530 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1531 creating it if needed.
1533 @item --listen=localhost
1534 @cindex daemon, remote access
1535 @cindex remote access to the daemon
1536 @cindex daemon, cluster setup
1537 @cindex clusters, daemon setup
1538 Listen for TCP connections on the network interface corresponding to
1539 @code{localhost}, on port 44146.
1541 @item --listen=128.0.0.42:1234
1542 Listen for TCP connections on the network interface corresponding to
1543 @code{128.0.0.42}, on port 1234.
1546 This option can be repeated multiple times, in which case
1547 @command{guix-daemon} accepts connections on all the specified
1548 endpoints. Users can tell client commands what endpoint to connect to
1549 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1550 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1553 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1554 @code{--listen=@var{host}} is suitable on local networks, such as
1555 clusters, where only trusted nodes may connect to the build daemon. In
1556 other cases where remote access to the daemon is needed, we recommend
1557 using Unix-domain sockets along with SSH.
1560 When @code{--listen} is omitted, @command{guix-daemon} listens for
1561 connections on the Unix-domain socket located at
1562 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1566 @node Application Setup
1567 @section Application Setup
1569 @cindex foreign distro
1570 When using Guix on top of GNU/Linux distribution other than Guix System---a
1571 so-called @dfn{foreign distro}---a few additional steps are needed to
1572 get everything in place. Here are some of them.
1576 @anchor{locales-and-locpath}
1577 @cindex locales, when not on Guix System
1579 @vindex GUIX_LOCPATH
1580 Packages installed @i{via} Guix will not use the locale data of the
1581 host system. Instead, you must first install one of the locale packages
1582 available with Guix and then define the @code{GUIX_LOCPATH} environment
1586 $ guix install glibc-locales
1587 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1590 Note that the @code{glibc-locales} package contains data for all the
1591 locales supported by the GNU@tie{}libc and weighs in at around
1592 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1593 limited to a few UTF-8 locales.
1595 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1596 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1597 Manual}). There are two important differences though:
1601 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1602 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1603 to make sure the programs of the foreign distro will not end up loading
1604 incompatible locale data.
1607 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1608 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1609 should your Guix profile contain a mixture of programs linked against
1610 different libc version, each libc version will only try to load locale
1611 data in the right format.
1614 This is important because the locale data format used by different libc
1615 versions may be incompatible.
1617 @subsection Name Service Switch
1619 @cindex name service switch, glibc
1620 @cindex NSS (name service switch), glibc
1621 @cindex nscd (name service caching daemon)
1622 @cindex name service caching daemon (nscd)
1623 When using Guix on a foreign distro, we @emph{strongly recommend} that
1624 the system run the GNU C library's @dfn{name service cache daemon},
1625 @command{nscd}, which should be listening on the
1626 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1627 installed with Guix may fail to look up host names or user accounts, or
1628 may even crash. The next paragraphs explain why.
1630 @cindex @file{nsswitch.conf}
1631 The GNU C library implements a @dfn{name service switch} (NSS), which is
1632 an extensible mechanism for ``name lookups'' in general: host name
1633 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1634 The GNU C Library Reference Manual}).
1636 @cindex Network information service (NIS)
1637 @cindex NIS (Network information service)
1638 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1639 lookup implementations: for example, the @code{nss-mdns} plugin allow
1640 resolution of @code{.local} host names, the @code{nis} plugin allows
1641 user account lookup using the Network information service (NIS), and so
1642 on. These extra ``lookup services'' are configured system-wide in
1643 @file{/etc/nsswitch.conf}, and all the programs running on the system
1644 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1647 When they perform a name lookup---for instance by calling the
1648 @code{getaddrinfo} function in C---applications first try to connect to
1649 the nscd; on success, nscd performs name lookups on their behalf. If
1650 the nscd is not running, then they perform the name lookup by
1651 themselves, by loading the name lookup services into their own address
1652 space and running it. These name lookup services---the
1653 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1654 the host system's C library, rather than from the C library the
1655 application is linked against (the C library coming from Guix).
1657 And this is where the problem is: if your application is linked against
1658 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1659 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1660 likely crash or have its name lookups fail unexpectedly.
1662 Running @command{nscd} on the system, among other advantages, eliminates
1663 this binary incompatibility problem because those @code{libnss_*.so}
1664 files are loaded in the @command{nscd} process, not in applications
1667 @subsection X11 Fonts
1670 The majority of graphical applications use Fontconfig to locate and
1671 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1672 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1673 by default. Thus, to allow graphical applications installed with Guix
1674 to display fonts, you have to install fonts with Guix as well.
1675 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1676 @code{font-gnu-freefont-ttf}.
1678 To display text written in Chinese languages, Japanese, or Korean in
1679 graphical applications, consider installing
1680 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1681 has multiple outputs, one per language family (@pxref{Packages with
1682 Multiple Outputs}). For instance, the following command installs fonts
1683 for Chinese languages:
1686 guix install font-adobe-source-han-sans:cn
1689 @cindex @code{xterm}
1690 Older programs such as @command{xterm} do not use Fontconfig and instead
1691 rely on server-side font rendering. Such programs require to specify a
1692 full name of a font using XLFD (X Logical Font Description), like this:
1695 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1698 To be able to use such full names for the TrueType fonts installed in
1699 your Guix profile, you need to extend the font path of the X server:
1701 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1702 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1704 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1707 @cindex @code{xlsfonts}
1708 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1709 to make sure your TrueType fonts are listed there.
1711 @cindex @code{fc-cache}
1713 After installing fonts you may have to refresh the font cache to use
1714 them in applications. The same applies when applications installed via
1715 Guix do not seem to find fonts. To force rebuilding of the font cache
1716 run @code{fc-cache -rv}. The @code{fc-cache} command is provided by
1717 the @code{fontconfig} package.
1719 @subsection X.509 Certificates
1721 @cindex @code{nss-certs}
1722 The @code{nss-certs} package provides X.509 certificates, which allow
1723 programs to authenticate Web servers accessed over HTTPS.
1725 When using Guix on a foreign distro, you can install this package and
1726 define the relevant environment variables so that packages know where to
1727 look for certificates. @xref{X.509 Certificates}, for detailed
1730 @subsection Emacs Packages
1732 @cindex @code{emacs}
1733 When you install Emacs packages with Guix, the elisp files may be placed
1734 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1736 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1737 directory exists because potentially there may exist thousands of Emacs
1738 packages and storing all their files in a single directory may not be
1739 reliable (because of name conflicts). So we think using a separate
1740 directory for each package is a good idea. It is very similar to how
1741 the Emacs package system organizes the file structure (@pxref{Package
1742 Files,,, emacs, The GNU Emacs Manual}).
1744 By default, Emacs (installed with Guix) ``knows'' where these packages
1745 are placed, so you do not need to perform any configuration. If, for
1746 some reason, you want to avoid auto-loading Emacs packages installed
1747 with Guix, you can do so by running Emacs with @code{--no-site-file}
1748 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1750 @subsection The GCC toolchain
1755 Guix offers individual compiler packages such as @code{gcc} but if you
1756 are in need of a complete toolchain for compiling and linking source
1757 code what you really want is the @code{gcc-toolchain} package. This
1758 package provides a complete GCC toolchain for C/C++ development,
1759 including GCC itself, the GNU C Library (headers and binaries, plus
1760 debugging symbols in the @code{debug} output), Binutils, and a linker
1763 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1764 passed to the linker, add corresponding @code{-rpath} arguments, and
1765 invoke the actual linker with this new set of arguments. You can instruct the
1766 wrapper to refuse to link against libraries not in the store by setting the
1767 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1769 @node Upgrading Guix
1770 @section Upgrading Guix
1772 @cindex Upgrading Guix, on a foreign distro
1774 To upgrade Guix, run:
1780 @xref{Invoking guix pull}, for more information.
1782 @cindex upgrading Guix for the root user, on a foreign distro
1783 @cindex upgrading the Guix daemon, on a foreign distro
1784 @cindex @command{guix pull} for the root user, on a foreign distro
1786 On a foreign distro, you can upgrade the build daemon by running:
1793 followed by (assuming your distro uses the systemd service management
1797 systemctl restart guix-daemon.service
1800 On Guix System, upgrading the daemon is achieved by reconfiguring the
1801 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1805 @c *********************************************************************
1806 @node System Installation
1807 @chapter System Installation
1809 @cindex installing Guix System
1810 @cindex Guix System, installation
1811 This section explains how to install Guix System
1812 on a machine. Guix, as a package manager, can
1813 also be installed on top of a running GNU/Linux system,
1814 @pxref{Installation}.
1818 @c This paragraph is for people reading this from tty2 of the
1819 @c installation image.
1820 You are reading this documentation with an Info reader. For details on
1821 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1822 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1823 Info}. Hit @kbd{l} afterwards to come back here.
1825 Alternately, run @command{info info} in another tty to keep the manual
1831 * Limitations:: What you can expect.
1832 * Hardware Considerations:: Supported hardware.
1833 * USB Stick and DVD Installation:: Preparing the installation medium.
1834 * Preparing for Installation:: Networking, partitioning, etc.
1835 * Guided Graphical Installation:: Easy graphical installation.
1836 * Manual Installation:: Manual installation for wizards.
1837 * After System Installation:: When installation succeeded.
1838 * Installing Guix in a VM:: Guix System playground.
1839 * Building the Installation Image:: How this comes to be.
1843 @section Limitations
1845 We consider Guix System to be ready for a wide range of ``desktop'' and server
1846 use cases. The reliability guarantees it provides---transactional upgrades
1847 and rollbacks, reproducibility---make it a solid foundation.
1849 Nevertheless, before you proceed with the installation, be aware of the
1850 following noteworthy limitations applicable to version @value{VERSION}:
1854 Support for the Logical Volume Manager (LVM) is missing.
1857 More and more system services are provided (@pxref{Services}), but some
1861 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1862 as well as a number of X11 window managers. However, KDE is currently
1866 More than a disclaimer, this is an invitation to report issues (and success
1867 stories!), and to join us in improving it. @xref{Contributing}, for more
1871 @node Hardware Considerations
1872 @section Hardware Considerations
1874 @cindex hardware support on Guix System
1875 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1876 builds around the kernel Linux-libre, which means that only hardware for
1877 which free software drivers and firmware exist is supported. Nowadays,
1878 a wide range of off-the-shelf hardware is supported on
1879 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1880 Ethernet controllers. Unfortunately, there are still areas where
1881 hardware vendors deny users control over their own computing, and such
1882 hardware is not supported on Guix System.
1884 @cindex WiFi, hardware support
1885 One of the main areas where free drivers or firmware are lacking is WiFi
1886 devices. WiFi devices known to work include those using Atheros chips
1887 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1888 driver, and those using Broadcom/AirForce chips (BCM43xx with
1889 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1890 Linux-libre driver. Free firmware exists for both and is available
1891 out-of-the-box on Guix System, as part of @code{%base-firmware}
1892 (@pxref{operating-system Reference, @code{firmware}}).
1894 @cindex RYF, Respects Your Freedom
1895 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1896 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1897 certification program for hardware products that respect your freedom
1898 and your privacy and ensure that you have control over your device. We
1899 encourage you to check the list of RYF-certified devices.
1901 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1902 web site. It contains a catalog of hardware devices with information
1903 about their support in GNU/Linux.
1906 @node USB Stick and DVD Installation
1907 @section USB Stick and DVD Installation
1909 An ISO-9660 installation image that can be written to a USB stick or
1910 burnt to a DVD can be downloaded from
1911 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1912 where @var{system} is one of:
1916 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1919 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1922 @c start duplication of authentication part from ``Binary Installation''
1923 Make sure to download the associated @file{.sig} file and to verify the
1924 authenticity of the image against it, along these lines:
1927 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1928 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1931 If that command fails because you do not have the required public key,
1932 then run this command to import it:
1935 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1936 -qO - | gpg --import -
1940 and rerun the @code{gpg --verify} command.
1942 Take note that a warning like ``This key is not certified with a trusted
1943 signature!'' is normal.
1947 This image contains the tools necessary for an installation.
1948 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1950 @unnumberedsubsec Copying to a USB Stick
1952 To copy the image to a USB stick, follow these steps:
1956 Decompress the image using the @command{xz} command:
1959 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1963 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1964 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1965 copy the image with:
1968 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1972 Access to @file{/dev/sdX} usually requires root privileges.
1975 @unnumberedsubsec Burning on a DVD
1977 To copy the image to a DVD, follow these steps:
1981 Decompress the image using the @command{xz} command:
1984 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1988 Insert a blank DVD into your machine, and determine
1989 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1990 copy the image with:
1993 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1996 Access to @file{/dev/srX} usually requires root privileges.
1999 @unnumberedsubsec Booting
2001 Once this is done, you should be able to reboot the system and boot from
2002 the USB stick or DVD. The latter usually requires you to get in the
2003 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2005 @xref{Installing Guix in a VM}, if, instead, you would like to install
2006 Guix System in a virtual machine (VM).
2009 @node Preparing for Installation
2010 @section Preparing for Installation
2012 Once you have booted, you can use the guided graphical installer, which makes
2013 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
2014 if you are already familiar with GNU/Linux and if you want more control than
2015 what the graphical installer provides, you can choose the ``manual''
2016 installation process (@pxref{Manual Installation}).
2018 The graphical installer is available on TTY1. You can obtain root shells on
2019 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2020 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2021 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2022 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2023 which allows you to select text with the left mouse button and to paste it
2024 with the middle button.
2027 Installation requires access to the Internet so that any missing
2028 dependencies of your system configuration can be downloaded. See the
2029 ``Networking'' section below.
2032 @node Guided Graphical Installation
2033 @section Guided Graphical Installation
2035 The graphical installer is a text-based user interface. It will guide you,
2036 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2038 The first dialog boxes allow you to set up the system as you use it during the
2039 installation: you can choose the language, keyboard layout, and set up
2040 networking, which will be used during the installation. The image below shows
2041 the networking dialog.
2043 @image{images/installer-network,5in,, networking setup with the graphical installer}
2045 Later steps allow you to partition your hard disk, as shown in the image
2046 below, to choose whether or not to use encrypted file systems, to enter the
2047 host name and root password, and to create an additional account, among other
2050 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2052 Note that, at any time, the installer allows you to exit the current
2053 installation step and resume at a previous step, as show in the image below.
2055 @image{images/installer-resume,5in,, resuming the installation process}
2057 Once you're done, the installer produces an operating system configuration and
2058 displays it (@pxref{Using the Configuration System}). At that point you can
2059 hit ``OK'' and installation will proceed. On success, you can reboot into the
2060 new system and enjoy. @xref{After System Installation}, for what's next!
2063 @node Manual Installation
2064 @section Manual Installation
2066 This section describes how you would ``manually'' install GNU@tie{}Guix System
2067 on your machine. This option requires familiarity with GNU/Linux, with the
2068 shell, and with common administration tools. If you think this is not for
2069 you, consider using the guided graphical installer (@pxref{Guided Graphical
2072 The installation system provides root shells on TTYs 3 to 6; press
2073 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2074 many common tools needed to install the system. But it is also a full-blown
2075 Guix System, which means that you can install additional packages, should you
2076 need it, using @command{guix package} (@pxref{Invoking guix package}).
2079 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2080 * Proceeding with the Installation:: Installing.
2083 @node Keyboard Layout and Networking and Partitioning
2084 @subsection Keyboard Layout, Networking, and Partitioning
2086 Before you can install the system, you may want to adjust the keyboard layout,
2087 set up networking, and partition your target hard disk. This section will
2088 guide you through this.
2090 @subsubsection Keyboard Layout
2092 @cindex keyboard layout
2093 The installation image uses the US qwerty keyboard layout. If you want
2094 to change it, you can use the @command{loadkeys} command. For example,
2095 the following command selects the Dvorak keyboard layout:
2101 See the files under @file{/run/current-system/profile/share/keymaps} for
2102 a list of available keyboard layouts. Run @command{man loadkeys} for
2105 @subsubsection Networking
2107 Run the following command to see what your network interfaces are called:
2114 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2120 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2121 Wired interfaces have a name starting with @samp{e}; for example, the
2122 interface corresponding to the first on-board Ethernet controller is
2123 called @samp{eno1}. Wireless interfaces have a name starting with
2124 @samp{w}, like @samp{w1p2s0}.
2127 @item Wired connection
2128 To configure a wired network run the following command, substituting
2129 @var{interface} with the name of the wired interface you want to use.
2132 ifconfig @var{interface} up
2136 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2139 ip link set @var{interface} up
2142 @item Wireless connection
2145 To configure wireless networking, you can create a configuration file
2146 for the @command{wpa_supplicant} configuration tool (its location is not
2147 important) using one of the available text editors such as
2151 nano wpa_supplicant.conf
2154 As an example, the following stanza can go to this file and will work
2155 for many wireless networks, provided you give the actual SSID and
2156 passphrase for the network you are connecting to:
2160 ssid="@var{my-ssid}"
2162 psk="the network's secret passphrase"
2166 Start the wireless service and run it in the background with the
2167 following command (substitute @var{interface} with the name of the
2168 network interface you want to use):
2171 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2174 Run @command{man wpa_supplicant} for more information.
2178 At this point, you need to acquire an IP address. On a network where IP
2179 addresses are automatically assigned @i{via} DHCP, you can run:
2182 dhclient -v @var{interface}
2185 Try to ping a server to see if networking is up and running:
2191 Setting up network access is almost always a requirement because the
2192 image does not contain all the software and tools that may be needed.
2194 @cindex installing over SSH
2195 If you want to, you can continue the installation remotely by starting
2199 herd start ssh-daemon
2202 Make sure to either set a password with @command{passwd}, or configure
2203 OpenSSH public key authentication before logging in.
2205 @subsubsection Disk Partitioning
2207 Unless this has already been done, the next step is to partition, and
2208 then format the target partition(s).
2210 The installation image includes several partitioning tools, including
2211 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2212 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2213 the partition layout you want:
2219 If your disk uses the GUID Partition Table (GPT) format and you plan to
2220 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2221 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2224 @cindex EFI, installation
2225 @cindex UEFI, installation
2226 @cindex ESP, EFI system partition
2227 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2228 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2229 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2232 parted /dev/sda set 1 esp on
2236 @vindex grub-bootloader
2237 @vindex grub-efi-bootloader
2238 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2239 @file{/sys/firmware/efi} exists in the installation image, then you should
2240 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2241 Otherwise you should use the BIOS-based GRUB, known as
2242 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2246 Once you are done partitioning the target hard disk drive, you have to
2247 create a file system on the relevant partition(s)@footnote{Currently
2248 Guix System only supports ext4 and btrfs file systems. In particular, code
2249 that reads file system UUIDs and labels only works for these file system
2250 types.}. For the ESP, if you have one and assuming it is
2251 @file{/dev/sda1}, run:
2254 mkfs.fat -F32 /dev/sda1
2257 Preferably, assign file systems a label so that you can easily and
2258 reliably refer to them in @code{file-system} declarations (@pxref{File
2259 Systems}). This is typically done using the @code{-L} option of
2260 @command{mkfs.ext4} and related commands. So, assuming the target root
2261 partition lives at @file{/dev/sda2}, a file system with the label
2262 @code{my-root} can be created with:
2265 mkfs.ext4 -L my-root /dev/sda2
2268 @cindex encrypted disk
2269 If you are instead planning to encrypt the root partition, you can use
2270 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2271 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2272 @code{man cryptsetup}} for more information.) Assuming you want to
2273 store the root partition on @file{/dev/sda2}, the command sequence would
2274 be along these lines:
2277 cryptsetup luksFormat /dev/sda2
2278 cryptsetup open --type luks /dev/sda2 my-partition
2279 mkfs.ext4 -L my-root /dev/mapper/my-partition
2282 Once that is done, mount the target file system under @file{/mnt}
2283 with a command like (again, assuming @code{my-root} is the label of the
2287 mount LABEL=my-root /mnt
2290 Also mount any other file systems you would like to use on the target
2291 system relative to this path. If you have opted for @file{/boot/efi} as an
2292 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2293 found by @code{guix system init} afterwards.
2295 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2296 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2297 sure to initialize them with @command{mkswap}. Assuming you have one
2298 swap partition on @file{/dev/sda3}, you would run:
2305 Alternatively, you may use a swap file. For example, assuming that in
2306 the new system you want to use the file @file{/swapfile} as a swap file,
2307 you would run@footnote{This example will work for many types of file
2308 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2309 btrfs), the required steps may be different. For details, see the
2310 manual pages for @command{mkswap} and @command{swapon}.}:
2313 # This is 10 GiB of swap space. Adjust "count" to change the size.
2314 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2315 # For security, make the file readable and writable only by root.
2316 chmod 600 /mnt/swapfile
2317 mkswap /mnt/swapfile
2318 swapon /mnt/swapfile
2321 Note that if you have encrypted the root partition and created a swap
2322 file in its file system as described above, then the encryption also
2323 protects the swap file, just like any other file in that file system.
2325 @node Proceeding with the Installation
2326 @subsection Proceeding with the Installation
2328 With the target partitions ready and the target root mounted on
2329 @file{/mnt}, we're ready to go. First, run:
2332 herd start cow-store /mnt
2335 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2336 during the installation phase are written to the target disk on @file{/mnt}
2337 rather than kept in memory. This is necessary because the first phase of
2338 the @command{guix system init} command (see below) entails downloads or
2339 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2341 Next, you have to edit a file and
2342 provide the declaration of the operating system to be installed. To
2343 that end, the installation system comes with three text editors. We
2344 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2345 supports syntax highlighting and parentheses matching; other editors
2346 include GNU Zile (an Emacs clone), and
2347 nvi (a clone of the original BSD @command{vi} editor).
2348 We strongly recommend storing that file on the target root file system, say,
2349 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2350 configuration file once you have rebooted into the newly-installed system.
2352 @xref{Using the Configuration System}, for an overview of the
2353 configuration file. The example configurations discussed in that
2354 section are available under @file{/etc/configuration} in the
2355 installation image. Thus, to get started with a system configuration
2356 providing a graphical display server (a ``desktop'' system), you can run
2357 something along these lines:
2361 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2362 # nano /mnt/etc/config.scm
2365 You should pay attention to what your configuration file contains, and
2370 Make sure the @code{bootloader-configuration} form refers to the target
2371 you want to install GRUB on. It should mention @code{grub-bootloader} if
2372 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2373 for newer UEFI systems. For legacy systems, the @code{target} field
2374 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2375 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2376 currently mounted and a @code{file-system} entry is specified in your
2380 Be sure that your file system labels match the value of their respective
2381 @code{device} fields in your @code{file-system} configuration, assuming
2382 your @code{file-system} configuration uses the @code{file-system-label}
2383 procedure in its @code{device} field.
2386 If there are encrypted or RAID partitions, make sure to add a
2387 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2390 Once you are done preparing the configuration file, the new system must
2391 be initialized (remember that the target root file system is mounted
2395 guix system init /mnt/etc/config.scm /mnt
2399 This copies all the necessary files and installs GRUB on
2400 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2401 more information, @pxref{Invoking guix system}. This command may trigger
2402 downloads or builds of missing packages, which can take some time.
2404 Once that command has completed---and hopefully succeeded!---you can run
2405 @command{reboot} and boot into the new system. The @code{root} password
2406 in the new system is initially empty; other users' passwords need to be
2407 initialized by running the @command{passwd} command as @code{root},
2408 unless your configuration specifies otherwise
2409 (@pxref{user-account-password, user account passwords}).
2410 @xref{After System Installation}, for what's next!
2413 @node After System Installation
2414 @section After System Installation
2416 Success, you've now booted into Guix System! From then on, you can update the
2417 system whenever you want by running, say:
2421 sudo guix system reconfigure /etc/config.scm
2425 This builds a new system generation with the latest packages and services
2426 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2427 your system includes the latest security updates (@pxref{Security Updates}).
2429 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2431 @cindex sudo vs. @command{guix pull}
2432 Note that @command{sudo guix} runs your user's @command{guix} command and
2433 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2434 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2437 Join us on @code{#guix} on the Freenode IRC network or on
2438 @email{guix-devel@@gnu.org} to share your experience!
2441 @node Installing Guix in a VM
2442 @section Installing Guix in a Virtual Machine
2444 @cindex virtual machine, Guix System installation
2445 @cindex virtual private server (VPS)
2446 @cindex VPS (virtual private server)
2447 If you'd like to install Guix System in a virtual machine (VM) or on a
2448 virtual private server (VPS) rather than on your beloved machine, this
2451 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2452 disk image, follow these steps:
2456 First, retrieve and decompress the Guix system installation image as
2457 described previously (@pxref{USB Stick and DVD Installation}).
2460 Create a disk image that will hold the installed system. To make a
2461 qcow2-formatted disk image, use the @command{qemu-img} command:
2464 qemu-img create -f qcow2 guix-system.img 50G
2467 The resulting file will be much smaller than 50 GB (typically less than
2468 1 MB), but it will grow as the virtualized storage device is filled up.
2471 Boot the USB installation image in an VM:
2474 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2475 -net user -net nic,model=virtio -boot menu=on,order=d \
2476 -drive file=guix-system.img \
2477 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2480 @code{-enable-kvm} is optional, but significantly improves performance,
2481 @pxref{Running Guix in a VM}.
2484 You're now root in the VM, proceed with the installation process.
2485 @xref{Preparing for Installation}, and follow the instructions.
2488 Once installation is complete, you can boot the system that's on your
2489 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2492 @node Building the Installation Image
2493 @section Building the Installation Image
2495 @cindex installation image
2496 The installation image described above was built using the @command{guix
2497 system} command, specifically:
2500 guix system disk-image --file-system-type=iso9660 \
2501 gnu/system/install.scm
2504 Have a look at @file{gnu/system/install.scm} in the source tree,
2505 and see also @ref{Invoking guix system} for more information
2506 about the installation image.
2508 @section Building the Installation Image for ARM Boards
2510 Many ARM boards require a specific variant of the
2511 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2513 If you build a disk image and the bootloader is not available otherwise
2514 (on another boot drive etc), it's advisable to build an image that
2515 includes the bootloader, specifically:
2518 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2521 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2522 board, a list of possible boards will be printed.
2524 @c *********************************************************************
2525 @node Package Management
2526 @chapter Package Management
2529 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2530 remove software packages, without having to know about their build
2531 procedures or dependencies. Guix also goes beyond this obvious set of
2534 This chapter describes the main features of Guix, as well as the
2535 package management tools it provides. Along with the command-line
2536 interface described below (@pxref{Invoking guix package, @code{guix
2537 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2538 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2539 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2543 guix install emacs-guix
2547 * Features:: How Guix will make your life brighter.
2548 * Invoking guix package:: Package installation, removal, etc.
2549 * Substitutes:: Downloading pre-built binaries.
2550 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2551 * Invoking guix gc:: Running the garbage collector.
2552 * Invoking guix pull:: Fetching the latest Guix and distribution.
2553 * Channels:: Customizing the package collection.
2554 * Invoking guix time-machine:: Running an older revision of Guix.
2555 * Inferiors:: Interacting with another revision of Guix.
2556 * Invoking guix describe:: Display information about your Guix revision.
2557 * Invoking guix archive:: Exporting and importing store files.
2563 When using Guix, each package ends up in the @dfn{package store}, in its
2564 own directory---something that resembles
2565 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2567 Instead of referring to these directories, users have their own
2568 @dfn{profile}, which points to the packages that they actually want to
2569 use. These profiles are stored within each user's home directory, at
2570 @code{$HOME/.guix-profile}.
2572 For example, @code{alice} installs GCC 4.7.2. As a result,
2573 @file{/home/alice/.guix-profile/bin/gcc} points to
2574 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2575 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2576 simply continues to point to
2577 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2578 coexist on the same system without any interference.
2580 The @command{guix package} command is the central tool to manage
2581 packages (@pxref{Invoking guix package}). It operates on the per-user
2582 profiles, and can be used @emph{with normal user privileges}.
2584 @cindex transactions
2585 The command provides the obvious install, remove, and upgrade
2586 operations. Each invocation is actually a @emph{transaction}: either
2587 the specified operation succeeds, or nothing happens. Thus, if the
2588 @command{guix package} process is terminated during the transaction,
2589 or if a power outage occurs during the transaction, then the user's
2590 profile remains in its previous state, and remains usable.
2592 In addition, any package transaction may be @emph{rolled back}. So, if,
2593 for example, an upgrade installs a new version of a package that turns
2594 out to have a serious bug, users may roll back to the previous instance
2595 of their profile, which was known to work well. Similarly, the global
2596 system configuration on Guix is subject to
2597 transactional upgrades and roll-back
2598 (@pxref{Using the Configuration System}).
2600 All packages in the package store may be @emph{garbage-collected}.
2601 Guix can determine which packages are still referenced by user
2602 profiles, and remove those that are provably no longer referenced
2603 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2604 generations of their profile so that the packages they refer to can be
2607 @cindex reproducibility
2608 @cindex reproducible builds
2609 Guix takes a @dfn{purely functional} approach to package
2610 management, as described in the introduction (@pxref{Introduction}).
2611 Each @file{/gnu/store} package directory name contains a hash of all the
2612 inputs that were used to build that package---compiler, libraries, build
2613 scripts, etc. This direct correspondence allows users to make sure a
2614 given package installation matches the current state of their
2615 distribution. It also helps maximize @dfn{build reproducibility}:
2616 thanks to the isolated build environments that are used, a given build
2617 is likely to yield bit-identical files when performed on different
2618 machines (@pxref{Invoking guix-daemon, container}).
2621 This foundation allows Guix to support @dfn{transparent binary/source
2622 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2623 available from an external source---a @dfn{substitute}, Guix just
2624 downloads it and unpacks it;
2625 otherwise, it builds the package from source, locally
2626 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2627 reproducible, users do not have to trust servers that provide
2628 substitutes: they can force a local build and @emph{challenge} providers
2629 (@pxref{Invoking guix challenge}).
2631 Control over the build environment is a feature that is also useful for
2632 developers. The @command{guix environment} command allows developers of
2633 a package to quickly set up the right development environment for their
2634 package, without having to manually install the dependencies of the
2635 package into their profile (@pxref{Invoking guix environment}).
2637 @cindex replication, of software environments
2638 @cindex provenance tracking, of software artifacts
2639 All of Guix and its package definitions is version-controlled, and
2640 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2641 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2642 Guix instance on a different machine or at a later point in time, which in
2643 turn allows you to @emph{replicate complete software environments}, while
2644 retaining precise @dfn{provenance tracking} of the software.
2646 @node Invoking guix package
2647 @section Invoking @command{guix package}
2649 @cindex installing packages
2650 @cindex removing packages
2651 @cindex package installation
2652 @cindex package removal
2653 The @command{guix package} command is the tool that allows users to
2654 install, upgrade, and remove packages, as well as rolling back to
2655 previous configurations. It operates only on the user's own profile,
2656 and works with normal user privileges (@pxref{Features}). Its syntax
2660 guix package @var{options}
2663 @cindex transactions
2664 Primarily, @var{options} specifies the operations to be performed during
2665 the transaction. Upon completion, a new profile is created, but
2666 previous @dfn{generations} of the profile remain available, should the user
2669 For example, to remove @code{lua} and install @code{guile} and
2670 @code{guile-cairo} in a single transaction:
2673 guix package -r lua -i guile guile-cairo
2676 @cindex aliases, for @command{guix package}
2677 For your convenience, we also provide the following aliases:
2681 @command{guix search} is an alias for @command{guix package -s},
2683 @command{guix install} is an alias for @command{guix package -i},
2685 @command{guix remove} is an alias for @command{guix package -r},
2687 @command{guix upgrade} is an alias for @command{guix package -u},
2689 and @command{guix show} is an alias for @command{guix package --show=}.
2692 These aliases are less expressive than @command{guix package} and provide
2693 fewer options, so in some cases you'll probably want to use @command{guix
2696 @command{guix package} also supports a @dfn{declarative approach}
2697 whereby the user specifies the exact set of packages to be available and
2698 passes it @i{via} the @option{--manifest} option
2699 (@pxref{profile-manifest, @option{--manifest}}).
2702 For each user, a symlink to the user's default profile is automatically
2703 created in @file{$HOME/.guix-profile}. This symlink always points to the
2704 current generation of the user's default profile. Thus, users can add
2705 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2706 variable, and so on.
2707 @cindex search paths
2708 If you are not using Guix System, consider adding the
2709 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2710 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2711 shells get all the right environment variable definitions:
2714 GUIX_PROFILE="$HOME/.guix-profile" ; \
2715 source "$HOME/.guix-profile/etc/profile"
2718 In a multi-user setup, user profiles are stored in a place registered as
2719 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2720 to (@pxref{Invoking guix gc}). That directory is normally
2721 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2722 @var{localstatedir} is the value passed to @code{configure} as
2723 @code{--localstatedir}, and @var{user} is the user name. The
2724 @file{per-user} directory is created when @command{guix-daemon} is
2725 started, and the @var{user} sub-directory is created by @command{guix
2728 The @var{options} can be among the following:
2732 @item --install=@var{package} @dots{}
2733 @itemx -i @var{package} @dots{}
2734 Install the specified @var{package}s.
2736 Each @var{package} may specify either a simple package name, such as
2737 @code{guile}, or a package name followed by an at-sign and version number,
2738 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2739 case, the newest version prefixed by @code{1.8} is selected.)
2741 If no version number is specified, the
2742 newest available version will be selected. In addition, @var{package}
2743 may contain a colon, followed by the name of one of the outputs of the
2744 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2745 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2746 name (and optionally version) are searched for among the GNU
2747 distribution modules (@pxref{Package Modules}).
2749 @cindex propagated inputs
2750 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2751 that automatically get installed along with the required package
2752 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2753 @code{package} objects}, for information about propagated inputs in
2754 package definitions).
2756 @anchor{package-cmd-propagated-inputs}
2757 An example is the GNU MPC library: its C header files refer to those of
2758 the GNU MPFR library, which in turn refer to those of the GMP library.
2759 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2760 in the profile; removing MPC also removes MPFR and GMP---unless they had
2761 also been explicitly installed by the user.
2763 Besides, packages sometimes rely on the definition of environment
2764 variables for their search paths (see explanation of
2765 @code{--search-paths} below). Any missing or possibly incorrect
2766 environment variable definitions are reported here.
2768 @item --install-from-expression=@var{exp}
2770 Install the package @var{exp} evaluates to.
2772 @var{exp} must be a Scheme expression that evaluates to a
2773 @code{<package>} object. This option is notably useful to disambiguate
2774 between same-named variants of a package, with expressions such as
2775 @code{(@@ (gnu packages base) guile-final)}.
2777 Note that this option installs the first output of the specified
2778 package, which may be insufficient when needing a specific output of a
2779 multiple-output package.
2781 @item --install-from-file=@var{file}
2782 @itemx -f @var{file}
2783 Install the package that the code within @var{file} evaluates to.
2785 As an example, @var{file} might contain a definition like this
2786 (@pxref{Defining Packages}):
2789 @include package-hello.scm
2792 Developers may find it useful to include such a @file{guix.scm} file
2793 in the root of their project source tree that can be used to test
2794 development snapshots and create reproducible development environments
2795 (@pxref{Invoking guix environment}).
2797 @item --remove=@var{package} @dots{}
2798 @itemx -r @var{package} @dots{}
2799 Remove the specified @var{package}s.
2801 As for @code{--install}, each @var{package} may specify a version number
2802 and/or output name in addition to the package name. For instance,
2803 @code{-r glibc:debug} would remove the @code{debug} output of
2806 @item --upgrade[=@var{regexp} @dots{}]
2807 @itemx -u [@var{regexp} @dots{}]
2808 @cindex upgrading packages
2809 Upgrade all the installed packages. If one or more @var{regexp}s are
2810 specified, upgrade only installed packages whose name matches a
2811 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2813 Note that this upgrades package to the latest version of packages found
2814 in the distribution currently installed. To update your distribution,
2815 you should regularly run @command{guix pull} (@pxref{Invoking guix
2818 @item --do-not-upgrade[=@var{regexp} @dots{}]
2819 When used together with the @code{--upgrade} option, do @emph{not}
2820 upgrade any packages whose name matches a @var{regexp}. For example, to
2821 upgrade all packages in the current profile except those containing the
2822 substring ``emacs'':
2825 $ guix package --upgrade . --do-not-upgrade emacs
2828 @item @anchor{profile-manifest}--manifest=@var{file}
2829 @itemx -m @var{file}
2830 @cindex profile declaration
2831 @cindex profile manifest
2832 Create a new generation of the profile from the manifest object
2833 returned by the Scheme code in @var{file}. This option can be repeated
2834 several times, in which case the manifests are concatenated.
2836 This allows you to @emph{declare} the profile's contents rather than
2837 constructing it through a sequence of @code{--install} and similar
2838 commands. The advantage is that @var{file} can be put under version
2839 control, copied to different machines to reproduce the same profile, and
2842 @c FIXME: Add reference to (guix profile) documentation when available.
2843 @var{file} must return a @dfn{manifest} object, which is roughly a list
2846 @findex packages->manifest
2848 (use-package-modules guile emacs)
2853 ;; Use a specific package output.
2854 (list guile-2.0 "debug")))
2857 @findex specifications->manifest
2858 In this example we have to know which modules define the @code{emacs}
2859 and @code{guile-2.0} variables to provide the right
2860 @code{use-package-modules} line, which can be cumbersome. We can
2861 instead provide regular package specifications and let
2862 @code{specifications->manifest} look up the corresponding package
2866 (specifications->manifest
2867 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2871 @cindex rolling back
2872 @cindex undoing transactions
2873 @cindex transactions, undoing
2874 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2875 the last transaction.
2877 When combined with options such as @code{--install}, roll back occurs
2878 before any other actions.
2880 When rolling back from the first generation that actually contains
2881 installed packages, the profile is made to point to the @dfn{zeroth
2882 generation}, which contains no files apart from its own metadata.
2884 After having rolled back, installing, removing, or upgrading packages
2885 overwrites previous future generations. Thus, the history of the
2886 generations in a profile is always linear.
2888 @item --switch-generation=@var{pattern}
2889 @itemx -S @var{pattern}
2891 Switch to a particular generation defined by @var{pattern}.
2893 @var{pattern} may be either a generation number or a number prefixed
2894 with ``+'' or ``-''. The latter means: move forward/backward by a
2895 specified number of generations. For example, if you want to return to
2896 the latest generation after @code{--roll-back}, use
2897 @code{--switch-generation=+1}.
2899 The difference between @code{--roll-back} and
2900 @code{--switch-generation=-1} is that @code{--switch-generation} will
2901 not make a zeroth generation, so if a specified generation does not
2902 exist, the current generation will not be changed.
2904 @item --search-paths[=@var{kind}]
2905 @cindex search paths
2906 Report environment variable definitions, in Bash syntax, that may be
2907 needed in order to use the set of installed packages. These environment
2908 variables are used to specify @dfn{search paths} for files used by some
2909 of the installed packages.
2911 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2912 environment variables to be defined so it can look for headers and
2913 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2914 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2915 library are installed in the profile, then @code{--search-paths} will
2916 suggest setting these variables to @code{@var{profile}/include} and
2917 @code{@var{profile}/lib}, respectively.
2919 The typical use case is to define these environment variables in the
2923 $ eval `guix package --search-paths`
2926 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2927 meaning that the returned environment variable definitions will either
2928 be exact settings, or prefixes or suffixes of the current value of these
2929 variables. When omitted, @var{kind} defaults to @code{exact}.
2931 This option can also be used to compute the @emph{combined} search paths
2932 of several profiles. Consider this example:
2935 $ guix package -p foo -i guile
2936 $ guix package -p bar -i guile-json
2937 $ guix package -p foo -p bar --search-paths
2940 The last command above reports about the @code{GUILE_LOAD_PATH}
2941 variable, even though, taken individually, neither @file{foo} nor
2942 @file{bar} would lead to that recommendation.
2945 @item --profile=@var{profile}
2946 @itemx -p @var{profile}
2947 Use @var{profile} instead of the user's default profile.
2949 @var{profile} must be the name of a file that will be created upon
2950 completion. Concretely, @var{profile} will be a mere symbolic link
2951 (``symlink'') pointing to the actual profile where packages are
2955 $ guix install hello -p ~/code/my-profile
2957 $ ~/code/my-profile/bin/hello
2961 All it takes to get rid of the profile is to remove this symlink and its
2962 siblings that point to specific generations:
2965 $ rm ~/code/my-profile ~/code/my-profile-*-link
2968 @item --list-profiles
2969 List all the user's profiles:
2972 $ guix package --list-profiles
2973 /home/charlie/.guix-profile
2974 /home/charlie/code/my-profile
2975 /home/charlie/code/devel-profile
2976 /home/charlie/tmp/test
2979 When running as root, list all the profiles of all the users.
2981 @cindex collisions, in a profile
2982 @cindex colliding packages in profiles
2983 @cindex profile collisions
2984 @item --allow-collisions
2985 Allow colliding packages in the new profile. Use at your own risk!
2987 By default, @command{guix package} reports as an error @dfn{collisions}
2988 in the profile. Collisions happen when two or more different versions
2989 or variants of a given package end up in the profile.
2992 Use the bootstrap Guile to build the profile. This option is only
2993 useful to distribution developers.
2997 In addition to these actions, @command{guix package} supports the
2998 following options to query the current state of a profile, or the
2999 availability of packages:
3003 @item --search=@var{regexp}
3004 @itemx -s @var{regexp}
3005 @cindex searching for packages
3006 List the available packages whose name, synopsis, or description matches
3007 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3008 Print all the metadata of matching packages in
3009 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3010 GNU recutils manual}).
3012 This allows specific fields to be extracted using the @command{recsel}
3013 command, for instance:
3016 $ guix package -s malloc | recsel -p name,version,relevance
3030 Similarly, to show the name of all the packages available under the
3031 terms of the GNU@tie{}LGPL version 3:
3034 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3041 It is also possible to refine search results using several @code{-s} flags to
3042 @command{guix package}, or several arguments to @command{guix search}. For
3043 example, the following command returns a list of board games (this time using
3044 the @command{guix search} alias):
3047 $ guix search '\<board\>' game | recsel -p name
3052 If we were to omit @code{-s game}, we would also get software packages
3053 that deal with printed circuit boards; removing the angle brackets
3054 around @code{board} would further add packages that have to do with
3057 And now for a more elaborate example. The following command searches
3058 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3059 libraries, and prints the name and synopsis of the matching packages:
3062 $ guix search crypto library | \
3063 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3067 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3068 information on @dfn{selection expressions} for @code{recsel -e}.
3070 @item --show=@var{package}
3071 Show details about @var{package}, taken from the list of available packages, in
3072 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3076 $ guix package --show=python | recsel -p name,version
3084 You may also specify the full name of a package to only get details about a
3085 specific version of it (this time using the @command{guix show} alias):
3087 $ guix show python@@3.4 | recsel -p name,version
3094 @item --list-installed[=@var{regexp}]
3095 @itemx -I [@var{regexp}]
3096 List the currently installed packages in the specified profile, with the
3097 most recently installed packages shown last. When @var{regexp} is
3098 specified, list only installed packages whose name matches @var{regexp}.
3100 For each installed package, print the following items, separated by
3101 tabs: the package name, its version string, the part of the package that
3102 is installed (for instance, @code{out} for the default output,
3103 @code{include} for its headers, etc.), and the path of this package in
3106 @item --list-available[=@var{regexp}]
3107 @itemx -A [@var{regexp}]
3108 List packages currently available in the distribution for this system
3109 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3110 installed packages whose name matches @var{regexp}.
3112 For each package, print the following items separated by tabs: its name,
3113 its version string, the parts of the package (@pxref{Packages with
3114 Multiple Outputs}), and the source location of its definition.
3116 @item --list-generations[=@var{pattern}]
3117 @itemx -l [@var{pattern}]
3119 Return a list of generations along with their creation dates; for each
3120 generation, show the installed packages, with the most recently
3121 installed packages shown last. Note that the zeroth generation is never
3124 For each installed package, print the following items, separated by
3125 tabs: the name of a package, its version string, the part of the package
3126 that is installed (@pxref{Packages with Multiple Outputs}), and the
3127 location of this package in the store.
3129 When @var{pattern} is used, the command returns only matching
3130 generations. Valid patterns include:
3133 @item @emph{Integers and comma-separated integers}. Both patterns denote
3134 generation numbers. For instance, @code{--list-generations=1} returns
3137 And @code{--list-generations=1,8,2} outputs three generations in the
3138 specified order. Neither spaces nor trailing commas are allowed.
3140 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3141 specified generations and everything in between. Note that the start of
3142 a range must be smaller than its end.
3144 It is also possible to omit the endpoint. For example,
3145 @code{--list-generations=2..}, returns all generations starting from the
3148 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3149 or months by passing an integer along with the first letter of the
3150 duration. For example, @code{--list-generations=20d} lists generations
3151 that are up to 20 days old.
3154 @item --delete-generations[=@var{pattern}]
3155 @itemx -d [@var{pattern}]
3156 When @var{pattern} is omitted, delete all generations except the current
3159 This command accepts the same patterns as @option{--list-generations}.
3160 When @var{pattern} is specified, delete the matching generations. When
3161 @var{pattern} specifies a duration, generations @emph{older} than the
3162 specified duration match. For instance, @code{--delete-generations=1m}
3163 deletes generations that are more than one month old.
3165 If the current generation matches, it is @emph{not} deleted. Also, the
3166 zeroth generation is never deleted.
3168 Note that deleting generations prevents rolling back to them.
3169 Consequently, this command must be used with care.
3173 Finally, since @command{guix package} may actually start build
3174 processes, it supports all the common build options (@pxref{Common Build
3175 Options}). It also supports package transformation options, such as
3176 @option{--with-source} (@pxref{Package Transformation Options}).
3177 However, note that package transformations are lost when upgrading; to
3178 preserve transformations across upgrades, you should define your own
3179 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3180 (@pxref{Defining Packages}).
3183 @section Substitutes
3186 @cindex pre-built binaries
3187 Guix supports transparent source/binary deployment, which means that it
3188 can either build things locally, or download pre-built items from a
3189 server, or both. We call these pre-built items @dfn{substitutes}---they
3190 are substitutes for local build results. In many cases, downloading a
3191 substitute is much faster than building things locally.
3193 Substitutes can be anything resulting from a derivation build
3194 (@pxref{Derivations}). Of course, in the common case, they are
3195 pre-built package binaries, but source tarballs, for instance, which
3196 also result from derivation builds, can be available as substitutes.
3199 * Official Substitute Server:: One particular source of substitutes.
3200 * Substitute Server Authorization:: How to enable or disable substitutes.
3201 * Substitute Authentication:: How Guix verifies substitutes.
3202 * Proxy Settings:: How to get substitutes via proxy.
3203 * Substitution Failure:: What happens when substitution fails.
3204 * On Trusting Binaries:: How can you trust that binary blob?
3207 @node Official Substitute Server
3208 @subsection Official Substitute Server
3211 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3212 that builds packages from Guix continuously for some
3213 architectures, and makes them available as substitutes. This is the
3214 default source of substitutes; it can be overridden by passing the
3215 @option{--substitute-urls} option either to @command{guix-daemon}
3216 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3217 or to client tools such as @command{guix package}
3218 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3221 Substitute URLs can be either HTTP or HTTPS.
3222 HTTPS is recommended because communications are encrypted; conversely,
3223 using HTTP makes all communications visible to an eavesdropper, who
3224 could use the information gathered to determine, for instance, whether
3225 your system has unpatched security vulnerabilities.
3227 Substitutes from the official build farm are enabled by default when
3228 using Guix System (@pxref{GNU Distribution}). However,
3229 they are disabled by default when using Guix on a foreign distribution,
3230 unless you have explicitly enabled them via one of the recommended
3231 installation steps (@pxref{Installation}). The following paragraphs
3232 describe how to enable or disable substitutes for the official build
3233 farm; the same procedure can also be used to enable substitutes for any
3234 other substitute server.
3236 @node Substitute Server Authorization
3237 @subsection Substitute Server Authorization
3240 @cindex substitutes, authorization thereof
3241 @cindex access control list (ACL), for substitutes
3242 @cindex ACL (access control list), for substitutes
3243 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3245 must add its public key to the access control list (ACL) of archive
3246 imports, using the @command{guix archive} command (@pxref{Invoking guix
3247 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3248 be compromised and to serve genuine substitutes.
3250 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3251 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3252 the installation prefix of Guix. If you installed Guix from source,
3253 make sure you checked the GPG signature of
3254 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3255 Then, you can run something like this:
3258 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3261 Once this is in place, the output of a command like @code{guix build}
3262 should change from something like:
3265 $ guix build emacs --dry-run
3266 The following derivations would be built:
3267 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3268 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3269 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3270 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3278 $ guix build emacs --dry-run
3279 112.3 MB would be downloaded:
3280 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3281 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3282 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3283 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3288 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3289 will be downloaded, when possible, for future builds.
3291 @cindex substitutes, how to disable
3292 The substitute mechanism can be disabled globally by running
3293 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3294 guix-daemon}). It can also be disabled temporarily by passing the
3295 @code{--no-substitutes} option to @command{guix package}, @command{guix
3296 build}, and other command-line tools.
3298 @node Substitute Authentication
3299 @subsection Substitute Authentication
3301 @cindex digital signatures
3302 Guix detects and raises an error when attempting to use a substitute
3303 that has been tampered with. Likewise, it ignores substitutes that are
3304 not signed, or that are not signed by one of the keys listed in the ACL.
3306 There is one exception though: if an unauthorized server provides
3307 substitutes that are @emph{bit-for-bit identical} to those provided by
3308 an authorized server, then the unauthorized server becomes eligible for
3309 downloads. For example, assume we have chosen two substitute servers
3313 --substitute-urls="https://a.example.org https://b.example.org"
3317 @cindex reproducible builds
3318 If the ACL contains only the key for @code{b.example.org}, and if
3319 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3320 then Guix will download substitutes from @code{a.example.org} because it
3321 comes first in the list and can be considered a mirror of
3322 @code{b.example.org}. In practice, independent build machines usually
3323 produce the same binaries, thanks to bit-reproducible builds (see
3326 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3327 (in other words, the server is not authenticated), contrary to what
3328 HTTPS clients such as Web browsers usually do. This is because Guix
3329 authenticates substitute information itself, as explained above, which
3330 is what we care about (whereas X.509 certificates are about
3331 authenticating bindings between domain names and public keys.)
3333 @node Proxy Settings
3334 @subsection Proxy Settings
3337 Substitutes are downloaded over HTTP or HTTPS.
3338 The @code{http_proxy} environment
3339 variable can be set in the environment of @command{guix-daemon} and is
3340 honored for downloads of substitutes. Note that the value of
3341 @code{http_proxy} in the environment where @command{guix build},
3342 @command{guix package}, and other client commands are run has
3343 @emph{absolutely no effect}.
3345 @node Substitution Failure
3346 @subsection Substitution Failure
3348 Even when a substitute for a derivation is available, sometimes the
3349 substitution attempt will fail. This can happen for a variety of
3350 reasons: the substitute server might be offline, the substitute may
3351 recently have been deleted, the connection might have been interrupted,
3354 When substitutes are enabled and a substitute for a derivation is
3355 available, but the substitution attempt fails, Guix will attempt to
3356 build the derivation locally depending on whether or not
3357 @code{--fallback} was given (@pxref{fallback-option,, common build
3358 option @code{--fallback}}). Specifically, if @code{--fallback} was
3359 omitted, then no local build will be performed, and the derivation is
3360 considered to have failed. However, if @code{--fallback} was given,
3361 then Guix will attempt to build the derivation locally, and the success
3362 or failure of the derivation depends on the success or failure of the
3363 local build. Note that when substitutes are disabled or no substitute
3364 is available for the derivation in question, a local build will
3365 @emph{always} be performed, regardless of whether or not
3366 @code{--fallback} was given.
3368 To get an idea of how many substitutes are available right now, you can
3369 try running the @command{guix weather} command (@pxref{Invoking guix
3370 weather}). This command provides statistics on the substitutes provided
3373 @node On Trusting Binaries
3374 @subsection On Trusting Binaries
3376 @cindex trust, of pre-built binaries
3377 Today, each individual's control over their own computing is at the
3378 mercy of institutions, corporations, and groups with enough power and
3379 determination to subvert the computing infrastructure and exploit its
3380 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3381 convenient, we encourage users to also build on their own, or even run
3382 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3383 interesting target. One way to help is by publishing the software you
3384 build using @command{guix publish} so that others have one more choice
3385 of server to download substitutes from (@pxref{Invoking guix publish}).
3387 Guix has the foundations to maximize build reproducibility
3388 (@pxref{Features}). In most cases, independent builds of a given
3389 package or derivation should yield bit-identical results. Thus, through
3390 a diverse set of independent package builds, we can strengthen the
3391 integrity of our systems. The @command{guix challenge} command aims to
3392 help users assess substitute servers, and to assist developers in
3393 finding out about non-deterministic package builds (@pxref{Invoking guix
3394 challenge}). Similarly, the @option{--check} option of @command{guix
3395 build} allows users to check whether previously-installed substitutes
3396 are genuine by rebuilding them locally (@pxref{build-check,
3397 @command{guix build --check}}).
3399 In the future, we want Guix to have support to publish and retrieve
3400 binaries to/from other users, in a peer-to-peer fashion. If you would
3401 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3403 @node Packages with Multiple Outputs
3404 @section Packages with Multiple Outputs
3406 @cindex multiple-output packages
3407 @cindex package outputs
3410 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3411 source package leads to exactly one directory in the store. When running
3412 @command{guix install glibc}, one installs the default output of the
3413 GNU libc package; the default output is called @code{out}, but its name
3414 can be omitted as shown in this command. In this particular case, the
3415 default output of @code{glibc} contains all the C header files, shared
3416 libraries, static libraries, Info documentation, and other supporting
3419 Sometimes it is more appropriate to separate the various types of files
3420 produced from a single source package into separate outputs. For
3421 instance, the GLib C library (used by GTK+ and related packages)
3422 installs more than 20 MiB of reference documentation as HTML pages.
3423 To save space for users who do not need it, the documentation goes to a
3424 separate output, called @code{doc}. To install the main GLib output,
3425 which contains everything but the documentation, one would run:
3431 @cindex documentation
3432 The command to install its documentation is:
3435 guix install glib:doc
3438 Some packages install programs with different ``dependency footprints''.
3439 For instance, the WordNet package installs both command-line tools and
3440 graphical user interfaces (GUIs). The former depend solely on the C
3441 library, whereas the latter depend on Tcl/Tk and the underlying X
3442 libraries. In this case, we leave the command-line tools in the default
3443 output, whereas the GUIs are in a separate output. This allows users
3444 who do not need the GUIs to save space. The @command{guix size} command
3445 can help find out about such situations (@pxref{Invoking guix size}).
3446 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3448 There are several such multiple-output packages in the GNU distribution.
3449 Other conventional output names include @code{lib} for libraries and
3450 possibly header files, @code{bin} for stand-alone programs, and
3451 @code{debug} for debugging information (@pxref{Installing Debugging
3452 Files}). The outputs of a packages are listed in the third column of
3453 the output of @command{guix package --list-available} (@pxref{Invoking
3457 @node Invoking guix gc
3458 @section Invoking @command{guix gc}
3460 @cindex garbage collector
3462 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3463 The @command{guix gc} command allows users to explicitly run the garbage
3464 collector to reclaim space from the @file{/gnu/store} directory. It is
3465 the @emph{only} way to remove files from @file{/gnu/store}---removing
3466 files or directories manually may break it beyond repair!
3469 @cindex garbage collector roots
3470 The garbage collector has a set of known @dfn{roots}: any file under
3471 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3472 cannot be deleted; any other file is considered @dfn{dead} and may be
3473 deleted. The set of garbage collector roots (``GC roots'' for short)
3474 includes default user profiles; by default, the symlinks under
3475 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3476 added with @command{guix build --root}, for example (@pxref{Invoking
3477 guix build}). The @command{guix gc --list-roots} command lists them.
3479 Prior to running @code{guix gc --collect-garbage} to make space, it is
3480 often useful to remove old generations from user profiles; that way, old
3481 package builds referenced by those generations can be reclaimed. This
3482 is achieved by running @code{guix package --delete-generations}
3483 (@pxref{Invoking guix package}).
3485 Our recommendation is to run a garbage collection periodically, or when
3486 you are short on disk space. For instance, to guarantee that at least
3487 5@tie{}GB are available on your disk, simply run:
3493 It is perfectly safe to run as a non-interactive periodic job
3494 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3495 Running @command{guix gc} with no arguments will collect as
3496 much garbage as it can, but that is often inconvenient: you may find
3497 yourself having to rebuild or re-download software that is ``dead'' from
3498 the GC viewpoint but that is necessary to build other pieces of
3499 software---e.g., the compiler tool chain.
3501 The @command{guix gc} command has three modes of operation: it can be
3502 used to garbage-collect any dead files (the default), to delete specific
3503 files (the @code{--delete} option), to print garbage-collector
3504 information, or for more advanced queries. The garbage collection
3505 options are as follows:
3508 @item --collect-garbage[=@var{min}]
3509 @itemx -C [@var{min}]
3510 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3511 sub-directories. This is the default operation when no option is
3514 When @var{min} is given, stop once @var{min} bytes have been collected.
3515 @var{min} may be a number of bytes, or it may include a unit as a
3516 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3517 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3519 When @var{min} is omitted, collect all the garbage.
3521 @item --free-space=@var{free}
3522 @itemx -F @var{free}
3523 Collect garbage until @var{free} space is available under
3524 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3525 as @code{500MiB}, as described above.
3527 When @var{free} or more is already available in @file{/gnu/store}, do
3528 nothing and exit immediately.
3530 @item --delete-generations[=@var{duration}]
3531 @itemx -d [@var{duration}]
3532 Before starting the garbage collection process, delete all the generations
3533 older than @var{duration}, for all the user profiles; when run as root, this
3534 applies to all the profiles @emph{of all the users}.
3536 For example, this command deletes all the generations of all your profiles
3537 that are older than 2 months (except generations that are current), and then
3538 proceeds to free space until at least 10 GiB are available:
3541 guix gc -d 2m -F 10G
3546 Attempt to delete all the store files and directories specified as
3547 arguments. This fails if some of the files are not in the store, or if
3548 they are still live.
3550 @item --list-failures
3551 List store items corresponding to cached build failures.
3553 This prints nothing unless the daemon was started with
3554 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3555 @option{--cache-failures}}).
3558 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3562 List store items in use by currently running processes. These store
3563 items are effectively considered GC roots: they cannot be deleted.
3565 @item --clear-failures
3566 Remove the specified store items from the failed-build cache.
3568 Again, this option only makes sense when the daemon is started with
3569 @option{--cache-failures}. Otherwise, it does nothing.
3572 Show the list of dead files and directories still present in the
3573 store---i.e., files and directories no longer reachable from any root.
3576 Show the list of live store files and directories.
3580 In addition, the references among existing store files can be queried:
3586 @cindex package dependencies
3587 List the references (respectively, the referrers) of store files given
3593 List the requisites of the store files passed as arguments. Requisites
3594 include the store files themselves, their references, and the references
3595 of these, recursively. In other words, the returned list is the
3596 @dfn{transitive closure} of the store files.
3598 @xref{Invoking guix size}, for a tool to profile the size of the closure
3599 of an element. @xref{Invoking guix graph}, for a tool to visualize
3600 the graph of references.
3604 Return the derivation(s) leading to the given store items
3605 (@pxref{Derivations}).
3607 For example, this command:
3610 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3614 returns the @file{.drv} file(s) leading to the @code{emacs} package
3615 installed in your profile.
3617 Note that there may be zero matching @file{.drv} files, for instance
3618 because these files have been garbage-collected. There can also be more
3619 than one matching @file{.drv} due to fixed-output derivations.
3622 Lastly, the following options allow you to check the integrity of the
3623 store and to control disk usage.
3627 @item --verify[=@var{options}]
3628 @cindex integrity, of the store
3629 @cindex integrity checking
3630 Verify the integrity of the store.
3632 By default, make sure that all the store items marked as valid in the
3633 database of the daemon actually exist in @file{/gnu/store}.
3635 When provided, @var{options} must be a comma-separated list containing one
3636 or more of @code{contents} and @code{repair}.
3638 When passing @option{--verify=contents}, the daemon computes the
3639 content hash of each store item and compares it against its hash in the
3640 database. Hash mismatches are reported as data corruptions. Because it
3641 traverses @emph{all the files in the store}, this command can take a
3642 long time, especially on systems with a slow disk drive.
3644 @cindex repairing the store
3645 @cindex corruption, recovering from
3646 Using @option{--verify=repair} or @option{--verify=contents,repair}
3647 causes the daemon to try to repair corrupt store items by fetching
3648 substitutes for them (@pxref{Substitutes}). Because repairing is not
3649 atomic, and thus potentially dangerous, it is available only to the
3650 system administrator. A lightweight alternative, when you know exactly
3651 which items in the store are corrupt, is @command{guix build --repair}
3652 (@pxref{Invoking guix build}).
3655 @cindex deduplication
3656 Optimize the store by hard-linking identical files---this is
3657 @dfn{deduplication}.
3659 The daemon performs deduplication after each successful build or archive
3660 import, unless it was started with @code{--disable-deduplication}
3661 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3662 this option is primarily useful when the daemon was running with
3663 @code{--disable-deduplication}.
3667 @node Invoking guix pull
3668 @section Invoking @command{guix pull}
3670 @cindex upgrading Guix
3671 @cindex updating Guix
3672 @cindex @command{guix pull}
3674 Packages are installed or upgraded to the latest version available in
3675 the distribution currently available on your local machine. To update
3676 that distribution, along with the Guix tools, you must run @command{guix
3677 pull}: the command downloads the latest Guix source code and package
3678 descriptions, and deploys it. Source code is downloaded from a
3679 @uref{https://git-scm.com, Git} repository, by default the official
3680 GNU@tie{}Guix repository, though this can be customized.
3682 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3683 (@pxref{Channels}) specified by one of the followings, in this order:
3687 the @option{--channels} option;
3689 the user's @file{~/.config/guix/channels.scm} file;
3691 the system-wide @file{/etc/guix/channels.scm} file;
3693 the built-in default channels specified in the @code{%default-channels}
3697 On completion, @command{guix package} will use packages and package
3698 versions from this just-retrieved copy of Guix. Not only that, but all
3699 the Guix commands and Scheme modules will also be taken from that latest
3700 version. New @command{guix} sub-commands added by the update also
3703 Any user can update their Guix copy using @command{guix pull}, and the
3704 effect is limited to the user who ran @command{guix pull}. For
3705 instance, when user @code{root} runs @command{guix pull}, this has no
3706 effect on the version of Guix that user @code{alice} sees, and vice
3709 The result of running @command{guix pull} is a @dfn{profile} available
3710 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3711 make sure to add it to the beginning of your search path so that you use
3712 the latest version, and similarly for the Info manual
3713 (@pxref{Documentation}):
3716 export PATH="$HOME/.config/guix/current/bin:$PATH"
3717 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3720 The @code{--list-generations} or @code{-l} option lists past generations
3721 produced by @command{guix pull}, along with details about their provenance:
3725 Generation 1 Jun 10 2018 00:18:18
3727 repository URL: https://git.savannah.gnu.org/git/guix.git
3728 branch: origin/master
3729 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3731 Generation 2 Jun 11 2018 11:02:49
3733 repository URL: https://git.savannah.gnu.org/git/guix.git
3734 branch: origin/master
3735 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3736 2 new packages: keepalived, libnfnetlink
3737 6 packages upgraded: emacs-nix-mode@@2.0.4,
3738 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3739 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3741 Generation 3 Jun 13 2018 23:31:07 (current)
3743 repository URL: https://git.savannah.gnu.org/git/guix.git
3744 branch: origin/master
3745 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3746 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3747 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3750 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3751 describe the current status of Guix.
3753 This @code{~/.config/guix/current} profile works exactly like the profiles
3754 created by @command{guix package} (@pxref{Invoking guix package}). That
3755 is, you can list generations, roll back to the previous
3756 generation---i.e., the previous Guix---and so on:
3759 $ guix pull --roll-back
3760 switched from generation 3 to 2
3761 $ guix pull --delete-generations=1
3762 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3765 You can also use @command{guix package} (@pxref{Invoking guix package})
3766 to manage the profile by naming it explicitly:
3768 $ guix package -p ~/.config/guix/current --roll-back
3769 switched from generation 3 to 2
3770 $ guix package -p ~/.config/guix/current --delete-generations=1
3771 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3774 The @command{guix pull} command is usually invoked with no arguments,
3775 but it supports the following options:
3778 @item --url=@var{url}
3779 @itemx --commit=@var{commit}
3780 @itemx --branch=@var{branch}
3781 Download code for the @code{guix} channel from the specified @var{url}, at the
3782 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3783 string), or @var{branch}.
3785 @cindex @file{channels.scm}, configuration file
3786 @cindex configuration file for channels
3787 These options are provided for convenience, but you can also specify your
3788 configuration in the @file{~/.config/guix/channels.scm} file or using the
3789 @option{--channels} option (see below).
3791 @item --channels=@var{file}
3792 @itemx -C @var{file}
3793 Read the list of channels from @var{file} instead of
3794 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3795 @var{file} must contain Scheme code that
3796 evaluates to a list of channel objects. @xref{Channels}, for more
3799 @cindex channel news
3802 Display the list of packages added or upgraded since the previous
3803 generation, as well as, occasionally, news written by channel authors
3804 for their users (@pxref{Channels, Writing Channel News}).
3806 The package information is the same as displayed upon @command{guix
3807 pull} completion, but without ellipses; it is also similar to the output
3808 of @command{guix pull -l} for the last generation (see below).
3810 @item --list-generations[=@var{pattern}]
3811 @itemx -l [@var{pattern}]
3812 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3813 is provided, the subset of generations that match @var{pattern}.
3814 The syntax of @var{pattern} is the same as with @code{guix package
3815 --list-generations} (@pxref{Invoking guix package}).
3818 @cindex rolling back
3819 @cindex undoing transactions
3820 @cindex transactions, undoing
3821 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3822 undo the last transaction.
3824 @item --switch-generation=@var{pattern}
3825 @itemx -S @var{pattern}
3827 Switch to a particular generation defined by @var{pattern}.
3829 @var{pattern} may be either a generation number or a number prefixed
3830 with ``+'' or ``-''. The latter means: move forward/backward by a
3831 specified number of generations. For example, if you want to return to
3832 the latest generation after @code{--roll-back}, use
3833 @code{--switch-generation=+1}.
3835 @item --delete-generations[=@var{pattern}]
3836 @itemx -d [@var{pattern}]
3837 When @var{pattern} is omitted, delete all generations except the current
3840 This command accepts the same patterns as @option{--list-generations}.
3841 When @var{pattern} is specified, delete the matching generations. When
3842 @var{pattern} specifies a duration, generations @emph{older} than the
3843 specified duration match. For instance, @code{--delete-generations=1m}
3844 deletes generations that are more than one month old.
3846 If the current generation matches, it is @emph{not} deleted.
3848 Note that deleting generations prevents rolling back to them.
3849 Consequently, this command must be used with care.
3851 @xref{Invoking guix describe}, for a way to display information about the
3852 current generation only.
3854 @item --profile=@var{profile}
3855 @itemx -p @var{profile}
3856 Use @var{profile} instead of @file{~/.config/guix/current}.
3860 Show which channel commit(s) would be used and what would be built or
3861 substituted but do not actually do it.
3863 @item --system=@var{system}
3864 @itemx -s @var{system}
3865 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3866 the system type of the build host.
3869 Produce verbose output, writing build logs to the standard error output.
3872 Use the bootstrap Guile to build the latest Guix. This option is only
3873 useful to Guix developers.
3876 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3877 repository and branch to pull from, as well as @emph{additional} repositories
3878 containing package modules that should be deployed. @xref{Channels}, for more
3881 In addition, @command{guix pull} supports all the common build options
3882 (@pxref{Common Build Options}).
3888 @cindex @file{channels.scm}, configuration file
3889 @cindex configuration file for channels
3890 @cindex @command{guix pull}, configuration file
3891 @cindex configuration of @command{guix pull}
3892 Guix and its package collection are updated by running @command{guix pull}
3893 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3894 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3895 customized by defining @dfn{channels} in the
3896 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3897 of a Git repository to be deployed, and @command{guix pull} can be instructed
3898 to pull from one or more channels. In other words, channels can be used to
3899 @emph{customize} and to @emph{extend} Guix, as we will see below.
3901 @subsection Using a Custom Guix Channel
3903 The channel called @code{guix} specifies where Guix itself---its command-line
3904 tools as well as its package collection---should be downloaded. For instance,
3905 suppose you want to update from your own copy of the Guix repository at
3906 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3907 write in @code{~/.config/guix/channels.scm} this specification:
3910 ;; Tell 'guix pull' to use my own repo.
3913 (url "https://example.org/my-guix.git")
3914 (branch "super-hacks")))
3918 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3919 branch of the repository at @code{example.org}.
3921 @subsection Specifying Additional Channels
3923 @cindex extending the package collection (channels)
3924 @cindex personal packages (channels)
3925 @cindex channels, for personal packages
3926 You can also specify @emph{additional channels} to pull from. Let's say you
3927 have a bunch of custom package variants or personal packages that you think
3928 would make little sense to contribute to the Guix project, but would like to
3929 have these packages transparently available to you at the command line. You
3930 would first write modules containing those package definitions (@pxref{Package
3931 Modules}), maintain them in a Git repository, and then you and anyone else can
3932 use it as an additional channel to get packages from. Neat, no?
3934 @c What follows stems from discussions at
3935 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3936 @c earlier discussions on guix-devel@gnu.org.
3938 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3939 publish your personal channel to the world, we would like to share a few words
3944 Before publishing a channel, please consider contributing your package
3945 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3946 to free software of all sorts, and packages in Guix proper are readily
3947 available to all Guix users and benefit from the project's quality assurance
3951 When you maintain package definitions outside Guix, we, Guix developers,
3952 consider that @emph{the compatibility burden is on you}. Remember that
3953 package modules and package definitions are just Scheme code that uses various
3954 programming interfaces (APIs). We want to remain free to change these APIs to
3955 keep improving Guix, possibly in ways that break your channel. We never
3956 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3960 Corollary: if you're using an external channel and that channel breaks, please
3961 @emph{report the issue to the channel authors}, not to the Guix project.
3964 You've been warned! Having said this, we believe external channels are a
3965 practical way to exert your freedom to augment Guix' package collection and to
3966 share your improvements, which are basic tenets of
3967 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3968 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3971 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3972 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3975 @vindex %default-channels
3977 ;; Add my personal packages to those Guix provides.
3979 (name 'my-personal-packages)
3980 (url "https://example.org/personal-packages.git"))
3985 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3986 add a channel the list of channels that the variable @code{%default-channels}
3987 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3988 Manual}). With this file in place, @command{guix pull} builds not only Guix
3989 but also the package modules from your own repository. The result in
3990 @file{~/.config/guix/current} is the union of Guix with your own package
3994 $ guix pull --list-generations
3996 Generation 19 Aug 27 2018 16:20:48
3998 repository URL: https://git.savannah.gnu.org/git/guix.git
4000 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4001 my-personal-packages dd3df5e
4002 repository URL: https://example.org/personal-packages.git
4004 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4005 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4006 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4010 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4011 both Guix and packages from the @code{my-personal-packages} channel. Among
4012 the new and upgraded packages that are listed, some like @code{my-gimp} and
4013 @code{my-emacs-with-cool-features} might come from
4014 @code{my-personal-packages}, while others come from the Guix default channel.
4016 To create a channel, create a Git repository containing your own package
4017 modules and make it available. The repository can contain anything, but a
4018 useful channel will contain Guile modules that export packages. Once you
4019 start using a channel, Guix will behave as if the root directory of that
4020 channel's Git repository has been added to the Guile load path (@pxref{Load
4021 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4022 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4023 module, then the module will be available under the name @code{(my-packages
4024 my-tools)}, and you will be able to use it like any other module
4025 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4027 @cindex dependencies, channels
4028 @cindex meta-data, channels
4029 @subsection Declaring Channel Dependencies
4031 Channel authors may decide to augment a package collection provided by other
4032 channels. They can declare their channel to be dependent on other channels in
4033 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4034 the channel repository.
4036 The meta-data file should contain a simple S-expression like this:
4043 (name some-collection)
4044 (url "https://example.org/first-collection.git"))
4046 (name some-other-collection)
4047 (url "https://example.org/second-collection.git")
4048 (branch "testing"))))
4051 In the above example this channel is declared to depend on two other channels,
4052 which will both be fetched automatically. The modules provided by the channel
4053 will be compiled in an environment where the modules of all these declared
4054 channels are available.
4056 For the sake of reliability and maintainability, you should avoid dependencies
4057 on channels that you don't control, and you should aim to keep the number of
4058 dependencies to a minimum.
4060 @cindex subdirectory, channels
4061 @subsection Package Modules in a Sub-directory
4063 As a channel author, you may want to keep your channel modules in a
4064 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4065 add a meta-data file @file{.guix-channel} that contains:
4073 @cindex news, for channels
4074 @subsection Writing Channel News
4076 Channel authors may occasionally want to communicate to their users
4077 information about important changes in the channel. You'd send them all
4078 an email, but that's not convenient.
4080 Instead, channels can provide a @dfn{news file}; when the channel users
4081 run @command{guix pull}, that news file is automatically read and
4082 @command{guix pull --news} can display the announcements that correspond
4083 to the new commits that have been pulled, if any.
4085 To do that, channel authors must first declare the name of the news file
4086 in their @file{.guix-channel} file:
4091 (news-file "etc/news.txt"))
4094 The news file itself, @file{etc/news.txt} in this example, must look
4095 something like this:
4100 (entry (tag "the-bug-fix")
4101 (title (en "Fixed terrible bug")
4103 (body (en "@@emph@{Good news@}! It's fixed!")
4104 (eo "Certe ĝi pli bone funkcias nun!")))
4105 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4106 (title (en "Added a great package")
4107 (ca "Què vol dir guix?"))
4108 (body (en "Don't miss the @@code@{hello@} package!"))))
4111 The file consists of a list of @dfn{news entries}. Each entry is
4112 associated with a commit or tag: it describes changes made in this
4113 commit, possibly in preceding commits as well. Users see entries only
4114 the first time they obtain the commit the entry refers to.
4116 The @code{title} field should be a one-line summary while @code{body}
4117 can be arbitrarily long, and both can contain Texinfo markup
4118 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4119 a list of language tag/message tuples, which allows @command{guix pull}
4120 to display news in the language that corresponds to the user's locale.
4122 If you want to translate news using a gettext-based workflow, you can
4123 extract translatable strings with @command{xgettext} (@pxref{xgettext
4124 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4125 you write news entries in English first, the command below creates a PO
4126 file containing the strings to translate:
4129 xgettext -o news.po -l scheme -ken etc/news.scm
4132 To sum up, yes, you could use your channel as a blog. But beware, this
4133 is @emph{not quite} what your users might expect.
4135 @subsection Replicating Guix
4137 @cindex pinning, channels
4138 @cindex replicating Guix
4139 @cindex reproducibility, of Guix
4140 The @command{guix pull --list-generations} output above shows precisely which
4141 commits were used to build this instance of Guix. We can thus replicate it,
4142 say, on another machine, by providing a channel specification in
4143 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4146 ;; Deploy specific commits of my channels of interest.
4149 (url "https://git.savannah.gnu.org/git/guix.git")
4150 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4152 (name 'my-personal-packages)
4153 (url "https://example.org/personal-packages.git")
4154 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4157 The @command{guix describe --format=channels} command can even generate this
4158 list of channels directly (@pxref{Invoking guix describe}). The resulting
4159 file can be used with the -C options of @command{guix pull}
4160 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4161 (@pxref{Invoking guix time-machine}).
4163 At this point the two machines run the @emph{exact same Guix}, with access to
4164 the @emph{exact same packages}. The output of @command{guix build gimp} on
4165 one machine will be exactly the same, bit for bit, as the output of the same
4166 command on the other machine. It also means both machines have access to all
4167 the source code of Guix and, transitively, to all the source code of every
4170 This gives you super powers, allowing you to track the provenance of binary
4171 artifacts with very fine grain, and to reproduce software environments at
4172 will---some sort of ``meta reproducibility'' capabilities, if you will.
4173 @xref{Inferiors}, for another way to take advantage of these super powers.
4175 @node Invoking guix time-machine
4176 @section Invoking @command{guix time-machine}
4178 @cindex @command{guix time-machine}
4179 @cindex pinning, channels
4180 @cindex replicating Guix
4181 @cindex reproducibility, of Guix
4183 The @command{guix time-machine} command provides access to other
4184 revisions of Guix, for example to install older versions of packages,
4185 or to reproduce a computation in an identical environment. The revision
4186 of Guix to be used is defined by a commit or by a channel
4187 description file created by @command{guix describe}
4188 (@pxref{Invoking guix describe}).
4190 The general syntax is:
4193 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4196 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4197 @command{guix} command if the specified revision. The @var{options} that define
4198 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4201 @item --url=@var{url}
4202 @itemx --commit=@var{commit}
4203 @itemx --branch=@var{branch}
4204 Use the @code{guix} channel from the specified @var{url}, at the
4205 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4206 string), or @var{branch}.
4208 @item --channels=@var{file}
4209 @itemx -C @var{file}
4210 Read the list of channels from @var{file}. @var{file} must contain
4211 Scheme code that evaluates to a list of channel objects.
4212 @xref{Channels} for more information.
4215 As for @command{guix pull}, the absence of any options means that the
4216 the latest commit on the master branch will be used. The command
4219 guix time-machine -- build hello
4222 will thus build the package @code{hello} as defined in the master branch,
4223 which is in general a newer revison of Guix than you have installed.
4224 Time travel works in both directions!
4226 Note that @command{guix time-machine} can trigger builds of channels and
4227 their dependencies, and these are controlled by the standard build
4228 options (@pxref{Common Build Options}).
4233 @c TODO: Remove this once we're more confident about API stability.
4235 The functionality described here is a ``technology preview'' as of version
4236 @value{VERSION}. As such, the interface is subject to change.
4240 @cindex composition of Guix revisions
4241 Sometimes you might need to mix packages from the revision of Guix you're
4242 currently running with packages available in a different revision of Guix.
4243 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4244 revisions in arbitrary ways.
4246 @cindex inferior packages
4247 Technically, an ``inferior'' is essentially a separate Guix process connected
4248 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4249 @code{(guix inferior)} module allows you to create inferiors and to
4250 communicate with them. It also provides a high-level interface to browse and
4251 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4253 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4254 to interact with a separate revision of Guix. For example, let's assume you
4255 want to install in your profile the current @code{guile} package, along with
4256 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4257 because the newer @code{guile-json} has an incompatible API and you want to
4258 run your code against the old API@. To do that, you could write a manifest for
4259 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4260 manifest, you would create an inferior for that old Guix revision you care
4261 about, and you would look up the @code{guile-json} package in the inferior:
4264 (use-modules (guix inferior) (guix channels)
4265 (srfi srfi-1)) ;for 'first'
4268 ;; This is the old revision from which we want to
4269 ;; extract guile-json.
4272 (url "https://git.savannah.gnu.org/git/guix.git")
4274 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4277 ;; An inferior representing the above revision.
4278 (inferior-for-channels channels))
4280 ;; Now create a manifest with the current "guile" package
4281 ;; and the old "guile-json" package.
4283 (list (first (lookup-inferior-packages inferior "guile-json"))
4284 (specification->package "guile")))
4287 On its first run, @command{guix package --manifest} might have to build the
4288 channel you specified before it can create the inferior; subsequent runs will
4289 be much faster because the Guix revision will be cached.
4291 The @code{(guix inferior)} module provides the following procedures to open an
4294 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4295 [#:cache-directory] [#:ttl]
4296 Return an inferior for @var{channels}, a list of channels. Use the cache at
4297 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4298 This procedure opens a new connection to the build daemon.
4300 As a side effect, this procedure may build or substitute binaries for
4301 @var{channels}, which can take time.
4304 @deffn {Scheme Procedure} open-inferior @var{directory} @
4305 [#:command "bin/guix"]
4306 Open the inferior Guix in @var{directory}, running
4307 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4308 the inferior could not be launched.
4311 @cindex inferior packages
4312 The procedures listed below allow you to obtain and manipulate inferior
4315 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4316 Return the list of packages known to @var{inferior}.
4319 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4321 Return the sorted list of inferior packages matching @var{name} in
4322 @var{inferior}, with highest version numbers first. If @var{version} is true,
4323 return only packages with a version number prefixed by @var{version}.
4326 @deffn {Scheme Procedure} inferior-package? @var{obj}
4327 Return true if @var{obj} is an inferior package.
4330 @deffn {Scheme Procedure} inferior-package-name @var{package}
4331 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4332 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4333 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4334 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4335 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4336 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4337 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4338 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4339 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4340 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4341 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4342 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4343 These procedures are the counterpart of package record accessors
4344 (@pxref{package Reference}). Most of them work by querying the inferior
4345 @var{package} comes from, so the inferior must still be live when you call
4349 Inferior packages can be used transparently like any other package or
4350 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4351 transparently handled by the @code{packages->manifest} procedure, which is
4352 commonly use in manifests (@pxref{Invoking guix package, the
4353 @option{--manifest} option of @command{guix package}}). Thus you can insert
4354 an inferior package pretty much anywhere you would insert a regular package:
4355 in manifests, in the @code{packages} field of your @code{operating-system}
4356 declaration, and so on.
4358 @node Invoking guix describe
4359 @section Invoking @command{guix describe}
4361 @cindex reproducibility
4362 @cindex replicating Guix
4363 Often you may want to answer questions like: ``Which revision of Guix am I
4364 using?'' or ``Which channels am I using?'' This is useful information in many
4365 situations: if you want to @emph{replicate} an environment on a different
4366 machine or user account, if you want to report a bug or to determine what
4367 change in the channels you are using caused it, or if you want to record your
4368 system state for reproducibility purposes. The @command{guix describe}
4369 command answers these questions.
4371 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4372 displays the channel(s) that it was built from, including their repository URL
4373 and commit IDs (@pxref{Channels}):
4377 Generation 10 Sep 03 2018 17:32:44 (current)
4379 repository URL: https://git.savannah.gnu.org/git/guix.git
4381 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4384 If you're familiar with the Git version control system, this is similar in
4385 spirit to @command{git describe}; the output is also similar to that of
4386 @command{guix pull --list-generations}, but limited to the current generation
4387 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4388 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4389 information is all it takes to describe the revision of Guix you're using, and
4390 also to replicate it.
4392 To make it easier to replicate Guix, @command{guix describe} can also be asked
4393 to return a list of channels instead of the human-readable description above:
4396 $ guix describe -f channels
4399 (url "https://git.savannah.gnu.org/git/guix.git")
4401 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4405 You can save this to a file and feed it to @command{guix pull -C} on some
4406 other machine or at a later point in time, which will instantiate @emph{this
4407 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4408 From there on, since you're able to deploy the same revision of Guix, you can
4409 just as well @emph{replicate a complete software environment}. We humbly
4410 think that this is @emph{awesome}, and we hope you'll like it too!
4412 The details of the options supported by @command{guix describe} are as
4416 @item --format=@var{format}
4417 @itemx -f @var{format}
4418 Produce output in the specified @var{format}, one of:
4422 produce human-readable output;
4424 produce a list of channel specifications that can be passed to @command{guix
4425 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4429 produce a list of channel specifications in JSON format;
4431 produce a list of channel specifications in Recutils format.
4434 @item --profile=@var{profile}
4435 @itemx -p @var{profile}
4436 Display information about @var{profile}.
4439 @node Invoking guix archive
4440 @section Invoking @command{guix archive}
4442 @cindex @command{guix archive}
4444 The @command{guix archive} command allows users to @dfn{export} files
4445 from the store into a single archive, and to later @dfn{import} them on
4446 a machine that runs Guix.
4447 In particular, it allows store files to be transferred from one machine
4448 to the store on another machine.
4451 If you're looking for a way to produce archives in a format suitable for
4452 tools other than Guix, @pxref{Invoking guix pack}.
4455 @cindex exporting store items
4456 To export store files as an archive to standard output, run:
4459 guix archive --export @var{options} @var{specifications}...
4462 @var{specifications} may be either store file names or package
4463 specifications, as for @command{guix package} (@pxref{Invoking guix
4464 package}). For instance, the following command creates an archive
4465 containing the @code{gui} output of the @code{git} package and the main
4466 output of @code{emacs}:
4469 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4472 If the specified packages are not built yet, @command{guix archive}
4473 automatically builds them. The build process may be controlled with the
4474 common build options (@pxref{Common Build Options}).
4476 To transfer the @code{emacs} package to a machine connected over SSH,
4480 guix archive --export -r emacs | ssh the-machine guix archive --import
4484 Similarly, a complete user profile may be transferred from one machine
4485 to another like this:
4488 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4489 ssh the-machine guix archive --import
4493 However, note that, in both examples, all of @code{emacs} and the
4494 profile as well as all of their dependencies are transferred (due to
4495 @code{-r}), regardless of what is already available in the store on the
4496 target machine. The @code{--missing} option can help figure out which
4497 items are missing from the target store. The @command{guix copy}
4498 command simplifies and optimizes this whole process, so this is probably
4499 what you should use in this case (@pxref{Invoking guix copy}).
4501 @cindex nar, archive format
4502 @cindex normalized archive (nar)
4503 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4504 comparable in spirit to `tar', but with differences
4505 that make it more appropriate for our purposes. First, rather than
4506 recording all Unix metadata for each file, the nar format only mentions
4507 the file type (regular, directory, or symbolic link); Unix permissions
4508 and owner/group are dismissed. Second, the order in which directory
4509 entries are stored always follows the order of file names according to
4510 the C locale collation order. This makes archive production fully
4513 When exporting, the daemon digitally signs the contents of the archive,
4514 and that digital signature is appended. When importing, the daemon
4515 verifies the signature and rejects the import in case of an invalid
4516 signature or if the signing key is not authorized.
4517 @c FIXME: Add xref to daemon doc about signatures.
4519 The main options are:
4523 Export the specified store files or packages (see below.) Write the
4524 resulting archive to the standard output.
4526 Dependencies are @emph{not} included in the output, unless
4527 @code{--recursive} is passed.
4531 When combined with @code{--export}, this instructs @command{guix
4532 archive} to include dependencies of the given items in the archive.
4533 Thus, the resulting archive is self-contained: it contains the closure
4534 of the exported store items.
4537 Read an archive from the standard input, and import the files listed
4538 therein into the store. Abort if the archive has an invalid digital
4539 signature, or if it is signed by a public key not among the authorized
4540 keys (see @code{--authorize} below.)
4543 Read a list of store file names from the standard input, one per line,
4544 and write on the standard output the subset of these files missing from
4547 @item --generate-key[=@var{parameters}]
4548 @cindex signing, archives
4549 Generate a new key pair for the daemon. This is a prerequisite before
4550 archives can be exported with @code{--export}. Note that this operation
4551 usually takes time, because it needs to gather enough entropy to
4552 generate the key pair.
4554 The generated key pair is typically stored under @file{/etc/guix}, in
4555 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4556 key, which must be kept secret.) When @var{parameters} is omitted,
4557 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4558 versions before 1.6.0, it is a 4096-bit RSA key.
4559 Alternatively, @var{parameters} can specify
4560 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4561 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4562 Libgcrypt Reference Manual}).
4565 @cindex authorizing, archives
4566 Authorize imports signed by the public key passed on standard input.
4567 The public key must be in ``s-expression advanced format''---i.e., the
4568 same format as the @file{signing-key.pub} file.
4570 The list of authorized keys is kept in the human-editable file
4571 @file{/etc/guix/acl}. The file contains
4572 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4573 s-expressions''} and is structured as an access-control list in the
4574 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4577 @item --extract=@var{directory}
4578 @itemx -x @var{directory}
4579 Read a single-item archive as served by substitute servers
4580 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4581 low-level operation needed in only very narrow use cases; see below.
4583 For example, the following command extracts the substitute for Emacs
4584 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4588 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4589 | bunzip2 | guix archive -x /tmp/emacs
4592 Single-item archives are different from multiple-item archives produced
4593 by @command{guix archive --export}; they contain a single store item,
4594 and they do @emph{not} embed a signature. Thus this operation does
4595 @emph{no} signature verification and its output should be considered
4598 The primary purpose of this operation is to facilitate inspection of
4599 archive contents coming from possibly untrusted substitute servers.
4604 @c *********************************************************************
4606 @chapter Development
4608 @cindex software development
4609 If you are a software developer, Guix provides tools that you should find
4610 helpful---independently of the language you're developing in. This is what
4611 this chapter is about.
4613 The @command{guix environment} command provides a convenient way to set up
4614 @dfn{development environments} containing all the dependencies and tools
4615 necessary to work on the software package of your choice. The @command{guix
4616 pack} command allows you to create @dfn{application bundles} that can be
4617 easily distributed to users who do not run Guix.
4620 * Invoking guix environment:: Setting up development environments.
4621 * Invoking guix pack:: Creating software bundles.
4624 @node Invoking guix environment
4625 @section Invoking @command{guix environment}
4627 @cindex reproducible build environments
4628 @cindex development environments
4629 @cindex @command{guix environment}
4630 @cindex environment, package build environment
4631 The purpose of @command{guix environment} is to assist hackers in
4632 creating reproducible development environments without polluting their
4633 package profile. The @command{guix environment} tool takes one or more
4634 packages, builds all of their inputs, and creates a shell
4635 environment to use them.
4637 The general syntax is:
4640 guix environment @var{options} @var{package}@dots{}
4643 The following example spawns a new shell set up for the development of
4647 guix environment guile
4650 If the needed dependencies are not built yet, @command{guix environment}
4651 automatically builds them. The environment of the new shell is an augmented
4652 version of the environment that @command{guix environment} was run in.
4653 It contains the necessary search paths for building the given package
4654 added to the existing environment variables. To create a ``pure''
4655 environment, in which the original environment variables have been unset,
4656 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4657 environment variables such as @code{PATH} in their @file{~/.bashrc}
4658 file. As a consequence, when @code{guix environment} launches it, Bash
4659 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4660 environment variables. It is an error to define such environment
4661 variables in @file{.bashrc}; instead, they should be defined in
4662 @file{.bash_profile}, which is sourced only by log-in shells.
4663 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4664 details on Bash start-up files.}.
4666 @vindex GUIX_ENVIRONMENT
4667 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4668 variable in the shell it spawns; its value is the file name of the
4669 profile of this environment. This allows users to, say, define a
4670 specific prompt for development environments in their @file{.bashrc}
4671 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4674 if [ -n "$GUIX_ENVIRONMENT" ]
4676 export PS1="\u@@\h \w [dev]\$ "
4681 ...@: or to browse the profile:
4684 $ ls "$GUIX_ENVIRONMENT/bin"
4687 Additionally, more than one package may be specified, in which case the
4688 union of the inputs for the given packages are used. For example, the
4689 command below spawns a shell where all of the dependencies of both Guile
4690 and Emacs are available:
4693 guix environment guile emacs
4696 Sometimes an interactive shell session is not desired. An arbitrary
4697 command may be invoked by placing the @code{--} token to separate the
4698 command from the rest of the arguments:
4701 guix environment guile -- make -j4
4704 In other situations, it is more convenient to specify the list of
4705 packages needed in the environment. For example, the following command
4706 runs @command{python} from an environment containing Python@tie{}2.7 and
4710 guix environment --ad-hoc python2-numpy python-2.7 -- python
4713 Furthermore, one might want the dependencies of a package and also some
4714 additional packages that are not build-time or runtime dependencies, but
4715 are useful when developing nonetheless. Because of this, the
4716 @code{--ad-hoc} flag is positional. Packages appearing before
4717 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4718 added to the environment. Packages appearing after are interpreted as
4719 packages that will be added to the environment directly. For example,
4720 the following command creates a Guix development environment that
4721 additionally includes Git and strace:
4724 guix environment guix --ad-hoc git strace
4727 Sometimes it is desirable to isolate the environment as much as
4728 possible, for maximal purity and reproducibility. In particular, when
4729 using Guix on a host distro that is not Guix System, it is desirable to
4730 prevent access to @file{/usr/bin} and other system-wide resources from
4731 the development environment. For example, the following command spawns
4732 a Guile REPL in a ``container'' where only the store and the current
4733 working directory are mounted:
4736 guix environment --ad-hoc --container guile -- guile
4740 The @code{--container} option requires Linux-libre 3.19 or newer.
4743 The available options are summarized below.
4746 @item --root=@var{file}
4747 @itemx -r @var{file}
4748 @cindex persistent environment
4749 @cindex garbage collector root, for environments
4750 Make @var{file} a symlink to the profile for this environment, and
4751 register it as a garbage collector root.
4753 This is useful if you want to protect your environment from garbage
4754 collection, to make it ``persistent''.
4756 When this option is omitted, the environment is protected from garbage
4757 collection only for the duration of the @command{guix environment}
4758 session. This means that next time you recreate the same environment,
4759 you could have to rebuild or re-download packages. @xref{Invoking guix
4760 gc}, for more on GC roots.
4762 @item --expression=@var{expr}
4763 @itemx -e @var{expr}
4764 Create an environment for the package or list of packages that
4765 @var{expr} evaluates to.
4767 For example, running:
4770 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4773 starts a shell with the environment for this specific variant of the
4779 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4782 starts a shell with all the base system packages available.
4784 The above commands only use the default output of the given packages.
4785 To select other outputs, two element tuples can be specified:
4788 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4791 @item --load=@var{file}
4792 @itemx -l @var{file}
4793 Create an environment for the package or list of packages that the code
4794 within @var{file} evaluates to.
4796 As an example, @var{file} might contain a definition like this
4797 (@pxref{Defining Packages}):
4800 @verbatiminclude environment-gdb.scm
4803 @item --manifest=@var{file}
4804 @itemx -m @var{file}
4805 Create an environment for the packages contained in the manifest object
4806 returned by the Scheme code in @var{file}. This option can be repeated
4807 several times, in which case the manifests are concatenated.
4809 This is similar to the same-named option in @command{guix package}
4810 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4814 Include all specified packages in the resulting environment, as if an
4815 @i{ad hoc} package were defined with them as inputs. This option is
4816 useful for quickly creating an environment without having to write a
4817 package expression to contain the desired inputs.
4819 For instance, the command:
4822 guix environment --ad-hoc guile guile-sdl -- guile
4825 runs @command{guile} in an environment where Guile and Guile-SDL are
4828 Note that this example implicitly asks for the default output of
4829 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4830 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4831 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4833 This option may be composed with the default behavior of @command{guix
4834 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4835 as packages whose dependencies will be added to the environment, the
4836 default behavior. Packages appearing after are interpreted as packages
4837 that will be added to the environment directly.
4840 Unset existing environment variables when building the new environment, except
4841 those specified with @option{--preserve} (see below.) This has the effect of
4842 creating an environment in which search paths only contain package inputs.
4844 @item --preserve=@var{regexp}
4845 @itemx -E @var{regexp}
4846 When used alongside @option{--pure}, preserve the environment variables
4847 matching @var{regexp}---in other words, put them on a ``white list'' of
4848 environment variables that must be preserved. This option can be repeated
4852 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4856 This example runs @command{mpirun} in a context where the only environment
4857 variables defined are @code{PATH}, environment variables whose name starts
4858 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4861 @item --search-paths
4862 Display the environment variable definitions that make up the
4865 @item --system=@var{system}
4866 @itemx -s @var{system}
4867 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4872 Run @var{command} within an isolated container. The current working
4873 directory outside the container is mapped inside the container.
4874 Additionally, unless overridden with @code{--user}, a dummy home
4875 directory is created that matches the current user's home directory, and
4876 @file{/etc/passwd} is configured accordingly.
4878 The spawned process runs as the current user outside the container. Inside
4879 the container, it has the same UID and GID as the current user, unless
4880 @option{--user} is passed (see below.)
4884 For containers, share the network namespace with the host system.
4885 Containers created without this flag only have access to the loopback
4888 @item --link-profile
4890 For containers, link the environment profile to
4891 @file{~/.guix-profile} within the container. This is equivalent to
4892 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4893 within the container. Linking will fail and abort the environment if
4894 the directory already exists, which will certainly be the case if
4895 @command{guix environment} was invoked in the user's home directory.
4897 Certain packages are configured to look in
4898 @code{~/.guix-profile} for configuration files and data;@footnote{For
4899 example, the @code{fontconfig} package inspects
4900 @file{~/.guix-profile/share/fonts} for additional fonts.}
4901 @code{--link-profile} allows these programs to behave as expected within
4904 @item --user=@var{user}
4905 @itemx -u @var{user}
4906 For containers, use the username @var{user} in place of the current
4907 user. The generated @file{/etc/passwd} entry within the container will
4908 contain the name @var{user}, the home directory will be
4909 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4910 the UID and GID inside the container are 1000. @var{user}
4911 need not exist on the system.
4913 Additionally, any shared or exposed path (see @code{--share} and
4914 @code{--expose} respectively) whose target is within the current user's
4915 home directory will be remapped relative to @file{/home/USER}; this
4916 includes the automatic mapping of the current working directory.
4919 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4921 guix environment --container --user=foo \
4922 --expose=$HOME/test \
4923 --expose=/tmp/target=$HOME/target
4926 While this will limit the leaking of user identity through home paths
4927 and each of the user fields, this is only one useful component of a
4928 broader privacy/anonymity solution---not one in and of itself.
4931 For containers, the default behavior is to share the current working
4932 directory with the isolated container and immediately change to that
4933 directory within the container. If this is undesirable, @code{--no-cwd}
4934 will cause the current working directory to @emph{not} be automatically
4935 shared and will change to the user's home directory within the container
4936 instead. See also @code{--user}.
4938 @item --expose=@var{source}[=@var{target}]
4939 For containers, expose the file system @var{source} from the host system
4940 as the read-only file system @var{target} within the container. If
4941 @var{target} is not specified, @var{source} is used as the target mount
4942 point in the container.
4944 The example below spawns a Guile REPL in a container in which the user's
4945 home directory is accessible read-only via the @file{/exchange}
4949 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4952 @item --share=@var{source}[=@var{target}]
4953 For containers, share the file system @var{source} from the host system
4954 as the writable file system @var{target} within the container. If
4955 @var{target} is not specified, @var{source} is used as the target mount
4956 point in the container.
4958 The example below spawns a Guile REPL in a container in which the user's
4959 home directory is accessible for both reading and writing via the
4960 @file{/exchange} directory:
4963 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4967 @command{guix environment}
4968 also supports all of the common build options that @command{guix
4969 build} supports (@pxref{Common Build Options}) as well as package
4970 transformation options (@pxref{Package Transformation Options}).
4972 @node Invoking guix pack
4973 @section Invoking @command{guix pack}
4975 Occasionally you want to pass software to people who are not (yet!)
4976 lucky enough to be using Guix. You'd tell them to run @command{guix
4977 package -i @var{something}}, but that's not possible in this case. This
4978 is where @command{guix pack} comes in.
4981 If you are looking for ways to exchange binaries among machines that
4982 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4983 publish}, and @ref{Invoking guix archive}.
4988 @cindex application bundle
4989 @cindex software bundle
4990 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4991 @dfn{software bundle}: it creates a tarball or some other archive
4992 containing the binaries of the software you're interested in, and all
4993 its dependencies. The resulting archive can be used on any machine that
4994 does not have Guix, and people can run the exact same binaries as those
4995 you have with Guix. The pack itself is created in a bit-reproducible
4996 fashion, so anyone can verify that it really contains the build results
4997 that you pretend to be shipping.
4999 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5000 their dependencies, you can run:
5003 $ guix pack guile emacs geiser
5005 /gnu/store/@dots{}-pack.tar.gz
5008 The result here is a tarball containing a @file{/gnu/store} directory
5009 with all the relevant packages. The resulting tarball contains a
5010 @dfn{profile} with the three packages of interest; the profile is the
5011 same as would be created by @command{guix package -i}. It is this
5012 mechanism that is used to create Guix's own standalone binary tarball
5013 (@pxref{Binary Installation}).
5015 Users of this pack would have to run
5016 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5017 find inconvenient. To work around it, you can create, say, a
5018 @file{/opt/gnu/bin} symlink to the profile:
5021 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5025 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5027 @cindex relocatable binaries, with @command{guix pack}
5028 What if the recipient of your pack does not have root privileges on
5029 their machine, and thus cannot unpack it in the root file system? In
5030 that case, you will want to use the @code{--relocatable} option (see
5031 below). This option produces @dfn{relocatable binaries}, meaning they
5032 they can be placed anywhere in the file system hierarchy: in the example
5033 above, users can unpack your tarball in their home directory and
5034 directly run @file{./opt/gnu/bin/guile}.
5036 @cindex Docker, build an image with guix pack
5037 Alternatively, you can produce a pack in the Docker image format using
5038 the following command:
5041 guix pack -f docker guile emacs geiser
5045 The result is a tarball that can be passed to the @command{docker load}
5047 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5048 documentation} for more information.
5050 @cindex Singularity, build an image with guix pack
5051 @cindex SquashFS, build an image with guix pack
5052 Yet another option is to produce a SquashFS image with the following
5056 guix pack -f squashfs guile emacs geiser
5060 The result is a SquashFS file system image that can either be mounted or
5061 directly be used as a file system container image with the
5062 @uref{https://singularity.lbl.gov, Singularity container execution
5063 environment}, using commands like @command{singularity shell} or
5064 @command{singularity exec}.
5066 Several command-line options allow you to customize your pack:
5069 @item --format=@var{format}
5070 @itemx -f @var{format}
5071 Produce a pack in the given @var{format}.
5073 The available formats are:
5077 This is the default format. It produces a tarball containing all the
5078 specified binaries and symlinks.
5081 This produces a tarball that follows the
5082 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5083 Docker Image Specification}. The ``repository name'' as it appears in
5084 the output of the @command{docker images} command is computed from
5085 package names passed on the command line or in the manifest file.
5088 This produces a SquashFS image containing all the specified binaries and
5089 symlinks, as well as empty mount points for virtual file systems like
5093 @cindex relocatable binaries
5096 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5097 anywhere in the file system hierarchy and run from there.
5099 When this option is passed once, the resulting binaries require support for
5100 @dfn{user namespaces} in the kernel Linux; when passed
5101 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5102 PRoot support, can be thought of as the abbreviation of ``Really
5103 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
5104 if user namespaces are unavailable, and essentially work anywhere---see below
5105 for the implications.
5107 For example, if you create a pack containing Bash with:
5110 guix pack -RR -S /mybin=bin bash
5114 ...@: you can copy that pack to a machine that lacks Guix, and from your
5115 home directory as a normal user, run:
5123 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5124 @file{/gnu/store} shows up and contains all the dependencies of
5125 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5126 altogether! That is probably the simplest way to deploy Guix-built
5127 software on a non-Guix machine.
5130 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5131 the kernel Linux, which allows unprivileged users to mount or change root.
5132 Old versions of Linux did not support it, and some GNU/Linux distributions
5135 To produce relocatable binaries that work even in the absence of user
5136 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5137 case, binaries will try user namespace support and fall back to PRoot if user
5138 namespaces are not supported.
5140 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
5141 support for file system virtualization. It achieves that by using the
5142 @code{ptrace} system call on the running program. This approach has the
5143 advantage to work without requiring special kernel support, but it incurs
5144 run-time overhead every time a system call is made.
5147 @cindex entry point, for Docker images
5148 @item --entry-point=@var{command}
5149 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5150 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5151 support it. @var{command} must be relative to the profile contained in the
5154 The entry point specifies the command that tools like @code{docker run} or
5155 @code{singularity run} automatically start by default. For example, you can
5159 guix pack -f docker --entry-point=bin/guile guile
5162 The resulting pack can easily be loaded and @code{docker run} with no extra
5163 arguments will spawn @code{bin/guile}:
5166 docker load -i pack.tar.gz
5167 docker run @var{image-id}
5170 @item --expression=@var{expr}
5171 @itemx -e @var{expr}
5172 Consider the package @var{expr} evaluates to.
5174 This has the same purpose as the same-named option in @command{guix
5175 build} (@pxref{Additional Build Options, @code{--expression} in
5176 @command{guix build}}).
5178 @item --manifest=@var{file}
5179 @itemx -m @var{file}
5180 Use the packages contained in the manifest object returned by the Scheme
5181 code in @var{file}. This option can be repeated several times, in which
5182 case the manifests are concatenated.
5184 This has a similar purpose as the same-named option in @command{guix
5185 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5186 same manifest files. It allows you to define a collection of packages
5187 once and use it both for creating profiles and for creating archives
5188 for use on machines that do not have Guix installed. Note that you can
5189 specify @emph{either} a manifest file @emph{or} a list of packages,
5192 @item --system=@var{system}
5193 @itemx -s @var{system}
5194 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5195 the system type of the build host.
5197 @item --target=@var{triplet}
5198 @cindex cross-compilation
5199 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5200 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5201 configuration triplets,, autoconf, Autoconf}).
5203 @item --compression=@var{tool}
5204 @itemx -C @var{tool}
5205 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5206 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
5208 @item --symlink=@var{spec}
5209 @itemx -S @var{spec}
5210 Add the symlinks specified by @var{spec} to the pack. This option can
5211 appear several times.
5213 @var{spec} has the form @code{@var{source}=@var{target}}, where
5214 @var{source} is the symlink that will be created and @var{target} is the
5217 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5218 symlink pointing to the @file{bin} sub-directory of the profile.
5220 @item --save-provenance
5221 Save provenance information for the packages passed on the command line.
5222 Provenance information includes the URL and commit of the channels in use
5225 Provenance information is saved in the
5226 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5227 usual package metadata---the name and version of each package, their
5228 propagated inputs, and so on. It is useful information to the recipient of
5229 the pack, who then knows how the pack was (supposedly) obtained.
5231 This option is not enabled by default because, like timestamps, provenance
5232 information contributes nothing to the build process. In other words, there
5233 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5234 Recording such ``silent'' metadata in the output thus potentially breaks the
5235 source-to-binary bitwise reproducibility property.
5237 @item --root=@var{file}
5238 @itemx -r @var{file}
5239 @cindex garbage collector root, for packs
5240 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5243 @item --localstatedir
5244 @itemx --profile-name=@var{name}
5245 Include the ``local state directory'', @file{/var/guix}, in the resulting
5246 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5247 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5248 @file{~root/.guix-profile}.
5250 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5251 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5252 the pack means that the store is ``complete'' and manageable by Guix;
5253 not providing it pack means that the store is ``dead'': items cannot be
5254 added to it or removed from it after extraction of the pack.
5256 One use case for this is the Guix self-contained binary tarball
5257 (@pxref{Binary Installation}).
5261 Print the name of the derivation that builds the pack.
5264 Use the bootstrap binaries to build the pack. This option is only
5265 useful to Guix developers.
5268 In addition, @command{guix pack} supports all the common build options
5269 (@pxref{Common Build Options}) and all the package transformation
5270 options (@pxref{Package Transformation Options}).
5273 @c *********************************************************************
5274 @node Programming Interface
5275 @chapter Programming Interface
5277 GNU Guix provides several Scheme programming interfaces (APIs) to
5278 define, build, and query packages. The first interface allows users to
5279 write high-level package definitions. These definitions refer to
5280 familiar packaging concepts, such as the name and version of a package,
5281 its build system, and its dependencies. These definitions can then be
5282 turned into concrete build actions.
5284 Build actions are performed by the Guix daemon, on behalf of users. In a
5285 standard setup, the daemon has write access to the store---the
5286 @file{/gnu/store} directory---whereas users do not. The recommended
5287 setup also has the daemon perform builds in chroots, under a specific
5288 build users, to minimize interference with the rest of the system.
5291 Lower-level APIs are available to interact with the daemon and the
5292 store. To instruct the daemon to perform a build action, users actually
5293 provide it with a @dfn{derivation}. A derivation is a low-level
5294 representation of the build actions to be taken, and the environment in
5295 which they should occur---derivations are to package definitions what
5296 assembly is to C programs. The term ``derivation'' comes from the fact
5297 that build results @emph{derive} from them.
5299 This chapter describes all these APIs in turn, starting from high-level
5300 package definitions.
5303 * Package Modules:: Packages from the programmer's viewpoint.
5304 * Defining Packages:: Defining new packages.
5305 * Build Systems:: Specifying how packages are built.
5306 * The Store:: Manipulating the package store.
5307 * Derivations:: Low-level interface to package derivations.
5308 * The Store Monad:: Purely functional interface to the store.
5309 * G-Expressions:: Manipulating build expressions.
5310 * Invoking guix repl:: Fiddling with Guix interactively.
5313 @node Package Modules
5314 @section Package Modules
5316 From a programming viewpoint, the package definitions of the
5317 GNU distribution are provided by Guile modules in the @code{(gnu packages
5318 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5319 packages @dots{})} module name space are not necessarily ``GNU
5320 packages''. This module naming scheme follows the usual Guile module
5321 naming convention: @code{gnu} means that these modules are distributed
5322 as part of the GNU system, and @code{packages} identifies modules that
5323 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5324 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5325 module exports a variable named @code{emacs}, which is bound to a
5326 @code{<package>} object (@pxref{Defining Packages}).
5328 The @code{(gnu packages @dots{})} module name space is
5329 automatically scanned for packages by the command-line tools. For
5330 instance, when running @code{guix install emacs}, all the @code{(gnu
5331 packages @dots{})} modules are scanned until one that exports a package
5332 object whose name is @code{emacs} is found. This package search
5333 facility is implemented in the @code{(gnu packages)} module.
5335 @cindex customization, of packages
5336 @cindex package module search path
5337 Users can store package definitions in modules with different
5338 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5339 name and module name must match. For instance, the @code{(my-packages
5340 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5341 relative to the load path specified with @option{--load-path} or
5342 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5343 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5344 these package definitions visible to the user interfaces:
5348 By adding the directory containing your package modules to the search path
5349 with the @code{-L} flag of @command{guix package} and other commands
5350 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5351 environment variable described below.
5354 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5355 pulls from it. A channel is essentially a Git repository containing package
5356 modules. @xref{Channels}, for more information on how to define and use
5360 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5362 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5363 This is a colon-separated list of directories to search for additional
5364 package modules. Directories listed in this variable take precedence
5365 over the own modules of the distribution.
5368 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5369 each package is built based solely on other packages in the
5370 distribution. The root of this dependency graph is a small set of
5371 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5372 bootstrap)} module. For more information on bootstrapping,
5373 @pxref{Bootstrapping}.
5375 @node Defining Packages
5376 @section Defining Packages
5378 The high-level interface to package definitions is implemented in the
5379 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5380 example, the package definition, or @dfn{recipe}, for the GNU Hello
5381 package looks like this:
5384 (define-module (gnu packages hello)
5385 #:use-module (guix packages)
5386 #:use-module (guix download)
5387 #:use-module (guix build-system gnu)
5388 #:use-module (guix licenses)
5389 #:use-module (gnu packages gawk))
5391 (define-public hello
5397 (uri (string-append "mirror://gnu/hello/hello-" version
5401 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5402 (build-system gnu-build-system)
5403 (arguments '(#:configure-flags '("--enable-silent-rules")))
5404 (inputs `(("gawk" ,gawk)))
5405 (synopsis "Hello, GNU world: An example GNU package")
5406 (description "Guess what GNU Hello prints!")
5407 (home-page "https://www.gnu.org/software/hello/")
5412 Without being a Scheme expert, the reader may have guessed the meaning
5413 of the various fields here. This expression binds the variable
5414 @code{hello} to a @code{<package>} object, which is essentially a record
5415 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5416 This package object can be inspected using procedures found in the
5417 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5418 returns---surprise!---@code{"hello"}.
5420 With luck, you may be able to import part or all of the definition of
5421 the package you are interested in from another repository, using the
5422 @code{guix import} command (@pxref{Invoking guix import}).
5424 In the example above, @var{hello} is defined in a module of its own,
5425 @code{(gnu packages hello)}. Technically, this is not strictly
5426 necessary, but it is convenient to do so: all the packages defined in
5427 modules under @code{(gnu packages @dots{})} are automatically known to
5428 the command-line tools (@pxref{Package Modules}).
5430 There are a few points worth noting in the above package definition:
5434 The @code{source} field of the package is an @code{<origin>} object
5435 (@pxref{origin Reference}, for the complete reference).
5436 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5437 meaning that the source is a file to be downloaded over FTP or HTTP.
5439 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5440 the GNU mirrors defined in @code{(guix download)}.
5442 The @code{sha256} field specifies the expected SHA256 hash of the file
5443 being downloaded. It is mandatory, and allows Guix to check the
5444 integrity of the file. The @code{(base32 @dots{})} form introduces the
5445 base32 representation of the hash. You can obtain this information with
5446 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5447 hash} (@pxref{Invoking guix hash}).
5450 When needed, the @code{origin} form can also have a @code{patches} field
5451 listing patches to be applied, and a @code{snippet} field giving a
5452 Scheme expression to modify the source code.
5455 @cindex GNU Build System
5456 The @code{build-system} field specifies the procedure to build the
5457 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5458 represents the familiar GNU Build System, where packages may be
5459 configured, built, and installed with the usual @code{./configure &&
5460 make && make check && make install} command sequence.
5463 The @code{arguments} field specifies options for the build system
5464 (@pxref{Build Systems}). Here it is interpreted by
5465 @var{gnu-build-system} as a request run @file{configure} with the
5466 @code{--enable-silent-rules} flag.
5472 What about these quote (@code{'}) characters? They are Scheme syntax to
5473 introduce a literal list; @code{'} is synonymous with @code{quote}.
5474 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5475 for details. Here the value of the @code{arguments} field is a list of
5476 arguments passed to the build system down the road, as with @code{apply}
5477 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5480 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5481 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5482 @code{#:configure-flags} is a keyword used to pass a keyword argument
5483 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5487 The @code{inputs} field specifies inputs to the build process---i.e.,
5488 build-time or run-time dependencies of the package. Here, we define an
5489 input called @code{"gawk"} whose value is that of the @var{gawk}
5490 variable; @var{gawk} is itself bound to a @code{<package>} object.
5492 @cindex backquote (quasiquote)
5495 @cindex comma (unquote)
5499 @findex unquote-splicing
5500 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5501 us to introduce a literal list in the @code{inputs} field, while
5502 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5503 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5506 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5507 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5508 of ensuring that they are present (@pxref{Build Systems}).
5510 However, any other dependencies need to be specified in the
5511 @code{inputs} field. Any dependency not specified here will simply be
5512 unavailable to the build process, possibly leading to a build failure.
5515 @xref{package Reference}, for a full description of possible fields.
5517 Once a package definition is in place, the
5518 package may actually be built using the @code{guix build} command-line
5519 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5520 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5521 package definition using the @command{guix edit} command
5522 (@pxref{Invoking guix edit}).
5523 @xref{Packaging Guidelines}, for
5524 more information on how to test package definitions, and
5525 @ref{Invoking guix lint}, for information on how to check a definition
5526 for style conformance.
5527 @vindex GUIX_PACKAGE_PATH
5528 Lastly, @pxref{Channels}, for information
5529 on how to extend the distribution by adding your own package definitions
5532 Finally, updating the package definition to a new upstream version
5533 can be partly automated by the @command{guix refresh} command
5534 (@pxref{Invoking guix refresh}).
5536 Behind the scenes, a derivation corresponding to the @code{<package>}
5537 object is first computed by the @code{package-derivation} procedure.
5538 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5539 The build actions it prescribes may then be realized by using the
5540 @code{build-derivations} procedure (@pxref{The Store}).
5542 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5543 Return the @code{<derivation>} object of @var{package} for @var{system}
5544 (@pxref{Derivations}).
5546 @var{package} must be a valid @code{<package>} object, and @var{system}
5547 must be a string denoting the target system type---e.g.,
5548 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5549 must be a connection to the daemon, which operates on the store
5550 (@pxref{The Store}).
5554 @cindex cross-compilation
5555 Similarly, it is possible to compute a derivation that cross-builds a
5556 package for some other system:
5558 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5559 @var{package} @var{target} [@var{system}]
5560 Return the @code{<derivation>} object of @var{package} cross-built from
5561 @var{system} to @var{target}.
5563 @var{target} must be a valid GNU triplet denoting the target hardware
5564 and operating system, such as @code{"mips64el-linux-gnu"}
5565 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5568 @cindex package transformations
5569 @cindex input rewriting
5570 @cindex dependency tree rewriting
5571 Packages can be manipulated in arbitrary ways. An example of a useful
5572 transformation is @dfn{input rewriting}, whereby the dependency tree of
5573 a package is rewritten by replacing specific inputs by others:
5575 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5576 [@var{rewrite-name}]
5577 Return a procedure that, when passed a package, replaces its direct and
5578 indirect dependencies (but not its implicit inputs) according to
5579 @var{replacements}. @var{replacements} is a list of package pairs; the
5580 first element of each pair is the package to replace, and the second one
5583 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5584 the name of a package and returns its new name after rewrite.
5588 Consider this example:
5591 (define libressl-instead-of-openssl
5592 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5594 (package-input-rewriting `((,openssl . ,libressl))))
5596 (define git-with-libressl
5597 (libressl-instead-of-openssl git))
5601 Here we first define a rewriting procedure that replaces @var{openssl}
5602 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5603 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5604 This is exactly what the @option{--with-input} command-line option does
5605 (@pxref{Package Transformation Options, @option{--with-input}}).
5607 The following variant of @code{package-input-rewriting} can match packages to
5608 be replaced by name rather than by identity.
5610 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5611 Return a procedure that, given a package, applies the given @var{replacements} to
5612 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5613 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5614 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5615 replacement for that package.
5618 The example above could be rewritten this way:
5621 (define libressl-instead-of-openssl
5622 ;; Replace all the packages called "openssl" with LibreSSL.
5623 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5626 The key difference here is that, this time, packages are matched by spec and
5627 not by identity. In other words, any package in the graph that is called
5628 @code{openssl} will be replaced.
5630 A more generic procedure to rewrite a package dependency graph is
5631 @code{package-mapping}: it supports arbitrary changes to nodes in the
5634 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5635 Return a procedure that, given a package, applies @var{proc} to all the packages
5636 depended on and returns the resulting package. The procedure stops recursion
5637 when @var{cut?} returns true for a given package.
5641 * package Reference:: The package data type.
5642 * origin Reference:: The origin data type.
5646 @node package Reference
5647 @subsection @code{package} Reference
5649 This section summarizes all the options available in @code{package}
5650 declarations (@pxref{Defining Packages}).
5652 @deftp {Data Type} package
5653 This is the data type representing a package recipe.
5657 The name of the package, as a string.
5659 @item @code{version}
5660 The version of the package, as a string.
5663 An object telling how the source code for the package should be
5664 acquired. Most of the time, this is an @code{origin} object, which
5665 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5666 can also be any other ``file-like'' object such as a @code{local-file},
5667 which denotes a file from the local file system (@pxref{G-Expressions,
5668 @code{local-file}}).
5670 @item @code{build-system}
5671 The build system that should be used to build the package (@pxref{Build
5674 @item @code{arguments} (default: @code{'()})
5675 The arguments that should be passed to the build system. This is a
5676 list, typically containing sequential keyword-value pairs.
5678 @item @code{inputs} (default: @code{'()})
5679 @itemx @code{native-inputs} (default: @code{'()})
5680 @itemx @code{propagated-inputs} (default: @code{'()})
5681 @cindex inputs, of packages
5682 These fields list dependencies of the package. Each one is a list of
5683 tuples, where each tuple has a label for the input (a string) as its
5684 first element, a package, origin, or derivation as its second element,
5685 and optionally the name of the output thereof that should be used, which
5686 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5687 more on package outputs). For example, the list below specifies three
5691 `(("libffi" ,libffi)
5692 ("libunistring" ,libunistring)
5693 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5696 @cindex cross compilation, package dependencies
5697 The distinction between @code{native-inputs} and @code{inputs} is
5698 necessary when considering cross-compilation. When cross-compiling,
5699 dependencies listed in @code{inputs} are built for the @emph{target}
5700 architecture; conversely, dependencies listed in @code{native-inputs}
5701 are built for the architecture of the @emph{build} machine.
5703 @code{native-inputs} is typically used to list tools needed at
5704 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5705 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5706 this area (@pxref{Invoking guix lint}).
5708 @anchor{package-propagated-inputs}
5709 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5710 specified packages will be automatically installed alongside the package
5711 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5712 package}}, for information on how @command{guix package} deals with
5715 For example this is necessary when a C/C++ library needs headers of
5716 another library to compile, or when a pkg-config file refers to another
5717 one @i{via} its @code{Requires} field.
5719 Another example where @code{propagated-inputs} is useful is for languages
5720 that lack a facility to record the run-time search path akin to the
5721 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5722 more. To ensure that libraries written in those languages can find
5723 library code they depend on at run time, run-time dependencies must be
5724 listed in @code{propagated-inputs} rather than @code{inputs}.
5726 @item @code{outputs} (default: @code{'("out")})
5727 The list of output names of the package. @xref{Packages with Multiple
5728 Outputs}, for typical uses of additional outputs.
5730 @item @code{native-search-paths} (default: @code{'()})
5731 @itemx @code{search-paths} (default: @code{'()})
5732 A list of @code{search-path-specification} objects describing
5733 search-path environment variables honored by the package.
5735 @item @code{replacement} (default: @code{#f})
5736 This must be either @code{#f} or a package object that will be used as a
5737 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5740 @item @code{synopsis}
5741 A one-line description of the package.
5743 @item @code{description}
5744 A more elaborate description of the package.
5746 @item @code{license}
5747 @cindex license, of packages
5748 The license of the package; a value from @code{(guix licenses)},
5749 or a list of such values.
5751 @item @code{home-page}
5752 The URL to the home-page of the package, as a string.
5754 @item @code{supported-systems} (default: @var{%supported-systems})
5755 The list of systems supported by the package, as strings of the form
5756 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5758 @item @code{location} (default: source location of the @code{package} form)
5759 The source location of the package. It is useful to override this when
5760 inheriting from another package, in which case this field is not
5761 automatically corrected.
5765 @deffn {Scheme Syntax} this-package
5766 When used in the @emph{lexical scope} of a package field definition, this
5767 identifier resolves to the package being defined.
5769 The example below shows how to add a package as a native input of itself when
5777 ;; When cross-compiled, Guile, for example, depends on
5778 ;; a native version of itself. Add it here.
5779 (native-inputs (if (%current-target-system)
5780 `(("self" ,this-package))
5784 It is an error to refer to @code{this-package} outside a package definition.
5787 @node origin Reference
5788 @subsection @code{origin} Reference
5790 This section summarizes all the options available in @code{origin}
5791 declarations (@pxref{Defining Packages}).
5793 @deftp {Data Type} origin
5794 This is the data type representing a source code origin.
5798 An object containing the URI of the source. The object type depends on
5799 the @code{method} (see below). For example, when using the
5800 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5801 values are: a URL represented as a string, or a list thereof.
5804 A procedure that handles the URI.
5809 @item @var{url-fetch} from @code{(guix download)}
5810 download a file from the HTTP, HTTPS, or FTP URL specified in the
5814 @item @var{git-fetch} from @code{(guix git-download)}
5815 clone the Git version control repository, and check out the revision
5816 specified in the @code{uri} field as a @code{git-reference} object; a
5817 @code{git-reference} looks like this:
5821 (url "https://git.savannah.gnu.org/git/hello.git")
5827 A bytevector containing the SHA-256 hash of the source. Typically the
5828 @code{base32} form is used here to generate the bytevector from a
5831 You can obtain this information using @code{guix download}
5832 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5835 @item @code{file-name} (default: @code{#f})
5836 The file name under which the source code should be saved. When this is
5837 @code{#f}, a sensible default value will be used in most cases. In case
5838 the source is fetched from a URL, the file name from the URL will be
5839 used. For version control checkouts, it is recommended to provide the
5840 file name explicitly because the default is not very descriptive.
5842 @item @code{patches} (default: @code{'()})
5843 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5844 file-like objects}) pointing to patches to be applied to the source.
5846 This list of patches must be unconditional. In particular, it cannot
5847 depend on the value of @code{%current-system} or
5848 @code{%current-target-system}.
5850 @item @code{snippet} (default: @code{#f})
5851 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5852 in the source directory. This is a convenient way to modify the source,
5853 sometimes more convenient than a patch.
5855 @item @code{patch-flags} (default: @code{'("-p1")})
5856 A list of command-line flags that should be passed to the @code{patch}
5859 @item @code{patch-inputs} (default: @code{#f})
5860 Input packages or derivations to the patching process. When this is
5861 @code{#f}, the usual set of inputs necessary for patching are provided,
5862 such as GNU@tie{}Patch.
5864 @item @code{modules} (default: @code{'()})
5865 A list of Guile modules that should be loaded during the patching
5866 process and while running the code in the @code{snippet} field.
5868 @item @code{patch-guile} (default: @code{#f})
5869 The Guile package that should be used in the patching process. When
5870 this is @code{#f}, a sensible default is used.
5876 @section Build Systems
5878 @cindex build system
5879 Each package definition specifies a @dfn{build system} and arguments for
5880 that build system (@pxref{Defining Packages}). This @code{build-system}
5881 field represents the build procedure of the package, as well as implicit
5882 dependencies of that build procedure.
5884 Build systems are @code{<build-system>} objects. The interface to
5885 create and manipulate them is provided by the @code{(guix build-system)}
5886 module, and actual build systems are exported by specific modules.
5888 @cindex bag (low-level package representation)
5889 Under the hood, build systems first compile package objects to
5890 @dfn{bags}. A @dfn{bag} is like a package, but with less
5891 ornamentation---in other words, a bag is a lower-level representation of
5892 a package, which includes all the inputs of that package, including some
5893 that were implicitly added by the build system. This intermediate
5894 representation is then compiled to a derivation (@pxref{Derivations}).
5896 Build systems accept an optional list of @dfn{arguments}. In package
5897 definitions, these are passed @i{via} the @code{arguments} field
5898 (@pxref{Defining Packages}). They are typically keyword arguments
5899 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5900 Guile Reference Manual}). The value of these arguments is usually
5901 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5902 by the daemon (@pxref{Derivations}).
5904 The main build system is @var{gnu-build-system}, which implements the
5905 standard build procedure for GNU and many other packages. It
5906 is provided by the @code{(guix build-system gnu)} module.
5908 @defvr {Scheme Variable} gnu-build-system
5909 @var{gnu-build-system} represents the GNU Build System, and variants
5910 thereof (@pxref{Configuration, configuration and makefile conventions,,
5911 standards, GNU Coding Standards}).
5913 @cindex build phases
5914 In a nutshell, packages using it are configured, built, and installed with
5915 the usual @code{./configure && make && make check && make install}
5916 command sequence. In practice, a few additional steps are often needed.
5917 All these steps are split up in separate @dfn{phases},
5918 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5919 modules for more details about the build phases.}:
5923 Unpack the source tarball, and change the current directory to the
5924 extracted source tree. If the source is actually a directory, copy it
5925 to the build tree, and enter that directory.
5927 @item patch-source-shebangs
5928 Patch shebangs encountered in source files so they refer to the right
5929 store file names. For instance, this changes @code{#!/bin/sh} to
5930 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5933 Run the @file{configure} script with a number of default options, such
5934 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5935 by the @code{#:configure-flags} argument.
5938 Run @code{make} with the list of flags specified with
5939 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5940 (the default), build with @code{make -j}.
5943 Run @code{make check}, or some other target specified with
5944 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5945 @code{#:parallel-tests?} argument is true (the default), run @code{make
5949 Run @code{make install} with the flags listed in @code{#:make-flags}.
5951 @item patch-shebangs
5952 Patch shebangs on the installed executable files.
5955 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5956 is false), copying them to the @code{debug} output when available
5957 (@pxref{Installing Debugging Files}).
5960 @vindex %standard-phases
5961 The build-side module @code{(guix build gnu-build-system)} defines
5962 @var{%standard-phases} as the default list of build phases.
5963 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5964 procedure implements the actual phase.
5966 The list of phases used for a particular package can be changed with the
5967 @code{#:phases} parameter. For instance, passing:
5970 #:phases (modify-phases %standard-phases (delete 'configure))
5973 means that all the phases described above will be used, except the
5974 @code{configure} phase.
5976 In addition, this build system ensures that the ``standard'' environment
5977 for GNU packages is available. This includes tools such as GCC, libc,
5978 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5979 build-system gnu)} module for a complete list). We call these the
5980 @dfn{implicit inputs} of a package, because package definitions do not
5981 have to mention them.
5984 Other @code{<build-system>} objects are defined to support other
5985 conventions and tools used by free software packages. They inherit most
5986 of @var{gnu-build-system}, and differ mainly in the set of inputs
5987 implicitly added to the build process, and in the list of phases
5988 executed. Some of these build systems are listed below.
5990 @defvr {Scheme Variable} ant-build-system
5991 This variable is exported by @code{(guix build-system ant)}. It
5992 implements the build procedure for Java packages that can be built with
5993 @url{https://ant.apache.org/, Ant build tool}.
5995 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5996 provided by the @code{icedtea} package to the set of inputs. Different
5997 packages can be specified with the @code{#:ant} and @code{#:jdk}
5998 parameters, respectively.
6000 When the original package does not provide a suitable Ant build file,
6001 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6002 build file @file{build.xml} with tasks to build the specified jar
6003 archive. In this case the parameter @code{#:source-dir} can be used to
6004 specify the source sub-directory, defaulting to ``src''.
6006 The @code{#:main-class} parameter can be used with the minimal ant
6007 buildfile to specify the main class of the resulting jar. This makes the
6008 jar file executable. The @code{#:test-include} parameter can be used to
6009 specify the list of junit tests to run. It defaults to
6010 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6011 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6012 because abstract classes cannot be run as tests.
6014 The parameter @code{#:build-target} can be used to specify the Ant task
6015 that should be run during the @code{build} phase. By default the
6016 ``jar'' task will be run.
6020 @defvr {Scheme Variable} android-ndk-build-system
6021 @cindex Android distribution
6022 @cindex Android NDK build system
6023 This variable is exported by @code{(guix build-system android-ndk)}. It
6024 implements a build procedure for Android NDK (native development kit)
6025 packages using a Guix-specific build process.
6027 The build system assumes that packages install their public interface
6028 (header) files to the subdirectory "include" of the "out" output and
6029 their libraries to the subdirectory "lib" of the "out" output.
6031 It's also assumed that the union of all the dependencies of a package
6032 has no conflicting files.
6034 For the time being, cross-compilation is not supported - so right now
6035 the libraries and header files are assumed to be host tools.
6039 @defvr {Scheme Variable} asdf-build-system/source
6040 @defvrx {Scheme Variable} asdf-build-system/sbcl
6041 @defvrx {Scheme Variable} asdf-build-system/ecl
6043 These variables, exported by @code{(guix build-system asdf)}, implement
6044 build procedures for Common Lisp packages using
6045 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6046 definition facility for Common Lisp programs and libraries.
6048 The @code{asdf-build-system/source} system installs the packages in
6049 source form, and can be loaded using any common lisp implementation, via
6050 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6051 systems in the format which a particular implementation understands.
6052 These build systems can also be used to produce executable programs, or
6053 lisp images which contain a set of packages pre-loaded.
6055 The build system uses naming conventions. For binary packages, the
6056 package name should be prefixed with the lisp implementation, such as
6057 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6059 Additionally, the corresponding source package should be labeled using
6060 the same convention as python packages (see @ref{Python Modules}), using
6061 the @code{cl-} prefix.
6063 For binary packages, each system should be defined as a Guix package.
6064 If one package @code{origin} contains several systems, package variants
6065 can be created in order to build all the systems. Source packages,
6066 which use @code{asdf-build-system/source}, may contain several systems.
6068 In order to create executable programs and images, the build-side
6069 procedures @code{build-program} and @code{build-image} can be used.
6070 They should be called in a build phase after the @code{create-symlinks}
6071 phase, so that the system which was just built can be used within the
6072 resulting image. @code{build-program} requires a list of Common Lisp
6073 expressions to be passed as the @code{#:entry-program} argument.
6075 If the system is not defined within its own @code{.asd} file of the same
6076 name, then the @code{#:asd-file} parameter should be used to specify
6077 which file the system is defined in. Furthermore, if the package
6078 defines a system for its tests in a separate file, it will be loaded
6079 before the tests are run if it is specified by the
6080 @code{#:test-asd-file} parameter. If it is not set, the files
6081 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6082 and @code{test.asd} will be tried if they exist.
6084 If for some reason the package must be named in a different way than the
6085 naming conventions suggest, the @code{#:asd-system-name} parameter can
6086 be used to specify the name of the system.
6090 @defvr {Scheme Variable} cargo-build-system
6091 @cindex Rust programming language
6092 @cindex Cargo (Rust build system)
6093 This variable is exported by @code{(guix build-system cargo)}. It
6094 supports builds of packages using Cargo, the build tool of the
6095 @uref{https://www.rust-lang.org, Rust programming language}.
6097 It adds @code{rustc} and @code{cargo} to the set of inputs.
6098 A different Rust package can be specified with the @code{#:rust} parameter.
6100 Regular cargo dependencies should be added to the package definition via the
6101 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6102 spec can be a package or a source definition. Note that the spec must
6103 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6104 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6105 should be added to the package definition via the
6106 @code{#:cargo-development-inputs} parameter.
6108 In its @code{configure} phase, this build system will make any source inputs
6109 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6110 parameters available to cargo. It will also remove an included
6111 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6112 @code{build} phase. The @code{install} phase installs any crate the binaries
6113 if they are defined by the crate.
6116 @cindex Clojure (programming language)
6117 @cindex simple Clojure build system
6118 @defvr {Scheme Variable} clojure-build-system
6119 This variable is exported by @code{(guix build-system clojure)}. It implements
6120 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6121 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6124 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6125 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6126 @code{#:zip} parameters, respectively.
6128 A list of source directories, test directories and jar names can be specified
6129 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6130 parameters, respectively. Compile directory and main class can be specified
6131 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6132 Other parameters are documented below.
6134 This build system is an extension of @var{ant-build-system}, but with the
6135 following phases changed:
6140 This phase calls @code{compile} in Clojure to compile source files and runs
6141 @command{jar} to create jars from both source files and compiled files
6142 according to the include list and exclude list specified in
6143 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6144 has priority over the include list. These lists consist of symbols
6145 representing Clojure libraries or the special keyword @code{#:all} representing
6146 all Clojure libraries found under the source directories. The parameter
6147 @code{#:omit-source?} decides if source should be included into the jars.
6150 This phase runs tests according to the include list and exclude list specified
6151 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6152 meanings are analogous to that of @code{#:aot-include} and
6153 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6154 stands for all Clojure libraries found under the test directories. The
6155 parameter @code{#:tests?} decides if tests should be run.
6158 This phase installs all jars built previously.
6161 Apart from the above, this build system also contains an additional phase:
6166 This phase installs all top-level files with base name matching
6167 @var{%doc-regex}. A different regex can be specified with the
6168 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6169 directories specified in @code{#:doc-dirs} are installed as well.
6173 @defvr {Scheme Variable} cmake-build-system
6174 This variable is exported by @code{(guix build-system cmake)}. It
6175 implements the build procedure for packages using the
6176 @url{https://www.cmake.org, CMake build tool}.
6178 It automatically adds the @code{cmake} package to the set of inputs.
6179 Which package is used can be specified with the @code{#:cmake}
6182 The @code{#:configure-flags} parameter is taken as a list of flags
6183 passed to the @command{cmake} command. The @code{#:build-type}
6184 parameter specifies in abstract terms the flags passed to the compiler;
6185 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6186 debugging information''), which roughly means that code is compiled with
6187 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6190 @defvr {Scheme Variable} dune-build-system
6191 This variable is exported by @code{(guix build-system dune)}. It
6192 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6193 tool for the OCaml programming language. It is implemented as an extension
6194 of the @code{ocaml-build-system} which is described below. As such, the
6195 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6198 It automatically adds the @code{dune} package to the set of inputs.
6199 Which package is used can be specified with the @code{#:dune}
6202 There is no @code{configure} phase because dune packages typically don't
6203 need to be configured. The @code{#:build-flags} parameter is taken as a
6204 list of flags passed to the @code{dune} command during the build.
6206 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6207 command instead of the more recent @code{dune} command while building
6208 a package. Its default value is @code{#f}.
6210 The @code{#:package} parameter can be passed to specify a package name, which
6211 is useful when a package contains multiple packages and you want to build
6212 only one of them. This is equivalent to passing the @code{-p} argument to
6216 @defvr {Scheme Variable} go-build-system
6217 This variable is exported by @code{(guix build-system go)}. It
6218 implements a build procedure for Go packages using the standard
6219 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6220 Go build mechanisms}.
6222 The user is expected to provide a value for the key @code{#:import-path}
6223 and, in some cases, @code{#:unpack-path}. The
6224 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6225 corresponds to the file system path expected by the package's build
6226 scripts and any referring packages, and provides a unique way to
6227 refer to a Go package. It is typically based on a combination of the
6228 package source code's remote URI and file system hierarchy structure. In
6229 some cases, you will need to unpack the package's source code to a
6230 different directory structure than the one indicated by the import path,
6231 and @code{#:unpack-path} should be used in such cases.
6233 Packages that provide Go libraries should install their source code into
6234 the built output. The key @code{#:install-source?}, which defaults to
6235 @code{#t}, controls whether or not the source code is installed. It can
6236 be set to @code{#f} for packages that only provide executable files.
6239 @defvr {Scheme Variable} glib-or-gtk-build-system
6240 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6241 is intended for use with packages making use of GLib or GTK+.
6243 This build system adds the following two phases to the ones defined by
6244 @var{gnu-build-system}:
6247 @item glib-or-gtk-wrap
6248 The phase @code{glib-or-gtk-wrap} ensures that programs in
6249 @file{bin/} are able to find GLib ``schemas'' and
6250 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6251 modules}. This is achieved by wrapping the programs in launch scripts
6252 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
6253 environment variables.
6255 It is possible to exclude specific package outputs from that wrapping
6256 process by listing their names in the
6257 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6258 when an output is known not to contain any GLib or GTK+ binaries, and
6259 where wrapping would gratuitously add a dependency of that output on
6262 @item glib-or-gtk-compile-schemas
6263 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6264 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6265 GSettings schemas} of GLib are compiled. Compilation is performed by the
6266 @command{glib-compile-schemas} program. It is provided by the package
6267 @code{glib:bin} which is automatically imported by the build system.
6268 The @code{glib} package providing @command{glib-compile-schemas} can be
6269 specified with the @code{#:glib} parameter.
6272 Both phases are executed after the @code{install} phase.
6275 @defvr {Scheme Variable} guile-build-system
6276 This build system is for Guile packages that consist exclusively of Scheme
6277 code and that are so lean that they don't even have a makefile, let alone a
6278 @file{configure} script. It compiles Scheme code using @command{guild
6279 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6280 installs the @file{.scm} and @file{.go} files in the right place. It also
6281 installs documentation.
6283 This build system supports cross-compilation by using the @code{--target}
6284 option of @command{guild compile}.
6286 Packages built with @code{guile-build-system} must provide a Guile package in
6287 their @code{native-inputs} field.
6290 @defvr {Scheme Variable} julia-build-system
6291 This variable is exported by @code{(guix build-system julia)}. It implements
6292 the build procedure used by @uref{https://julialang.org/, julia} packages,
6293 which essentially is similar to running @command{julia -e 'using Pkg;
6294 Pkg.add(package)'} in an environment where @code{JULIA_LOAD_PATH} contains the
6295 paths to all Julia package inputs. Tests are run not run.
6297 Julia packages require the source @code{file-name} to be the real name of the
6298 package, correctly capitalized.
6300 For packages requiring shared library dependencies, you may need to write the
6301 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6302 variable = /gnu/store/library.so} for each dependency, plus a void function
6303 @code{check_deps() = nothing}.
6305 Some older packages that aren't using @file{Package.toml} yet, will require
6306 this file to be created, too. The function @code{julia-create-package-toml}
6307 helps creating the file. You need to pass the outputs and the source of the
6308 package, it's name (the same as the @code{file-name} parameter), the package
6309 uuid, the package version, and a list of dependencies specified by their name
6313 @defvr {Scheme Variable} minify-build-system
6314 This variable is exported by @code{(guix build-system minify)}. It
6315 implements a minification procedure for simple JavaScript packages.
6317 It adds @code{uglify-js} to the set of inputs and uses it to compress
6318 all JavaScript files in the @file{src} directory. A different minifier
6319 package can be specified with the @code{#:uglify-js} parameter, but it
6320 is expected that the package writes the minified code to the standard
6323 When the input JavaScript files are not all located in the @file{src}
6324 directory, the parameter @code{#:javascript-files} can be used to
6325 specify a list of file names to feed to the minifier.
6328 @defvr {Scheme Variable} ocaml-build-system
6329 This variable is exported by @code{(guix build-system ocaml)}. It implements
6330 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6331 of choosing the correct set of commands to run for each package. OCaml
6332 packages can expect many different commands to be run. This build system will
6335 When the package has a @file{setup.ml} file present at the top-level, it will
6336 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6337 @code{ocaml setup.ml -install}. The build system will assume that this file
6338 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6339 care of setting the prefix and enabling tests if they are not disabled. You
6340 can pass configure and build flags with the @code{#:configure-flags} and
6341 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6342 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6343 bypass this system in the build and install phases.
6345 When the package has a @file{configure} file, it is assumed that it is a
6346 hand-made configure script that requires a different argument format than
6347 in the @code{gnu-build-system}. You can add more flags with the
6348 @code{#:configure-flags} key.
6350 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6351 @code{#t}), it will be used and more flags can be passed to the build and
6352 install phases with the @code{#:make-flags} key.
6354 Finally, some packages do not have these files and use a somewhat standard
6355 location for its build system. In that case, the build system will run
6356 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6357 providing the path to the required findlib module. Additional flags can
6358 be passed via the @code{#:build-flags} key. Install is taken care of by
6359 @command{opam-installer}. In this case, the @code{opam} package must
6360 be added to the @code{native-inputs} field of the package definition.
6362 Note that most OCaml packages assume they will be installed in the same
6363 directory as OCaml, which is not what we want in guix. In particular, they
6364 will install @file{.so} files in their module's directory, which is usually
6365 fine because it is in the OCaml compiler directory. In guix though, these
6366 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6367 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6368 @file{.so} libraries should be installed.
6371 @defvr {Scheme Variable} python-build-system
6372 This variable is exported by @code{(guix build-system python)}. It
6373 implements the more or less standard build procedure used by Python
6374 packages, which consists in running @code{python setup.py build} and
6375 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6377 For packages that install stand-alone Python programs under @code{bin/},
6378 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6379 environment variable points to all the Python libraries they depend on.
6381 Which Python package is used to perform the build can be specified with
6382 the @code{#:python} parameter. This is a useful way to force a package
6383 to be built for a specific version of the Python interpreter, which
6384 might be necessary if the package is only compatible with a single
6385 interpreter version.
6387 By default guix calls @code{setup.py} under control of
6388 @code{setuptools}, much like @command{pip} does. Some packages are not
6389 compatible with setuptools (and pip), thus you can disable this by
6390 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6393 @defvr {Scheme Variable} perl-build-system
6394 This variable is exported by @code{(guix build-system perl)}. It
6395 implements the standard build procedure for Perl packages, which either
6396 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6397 followed by @code{Build} and @code{Build install}; or in running
6398 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6399 @code{make} and @code{make install}, depending on which of
6400 @code{Build.PL} or @code{Makefile.PL} is present in the package
6401 distribution. Preference is given to the former if both @code{Build.PL}
6402 and @code{Makefile.PL} exist in the package distribution. This
6403 preference can be reversed by specifying @code{#t} for the
6404 @code{#:make-maker?} parameter.
6406 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6407 passes flags specified by the @code{#:make-maker-flags} or
6408 @code{#:module-build-flags} parameter, respectively.
6410 Which Perl package is used can be specified with @code{#:perl}.
6413 @defvr {Scheme Variable} r-build-system
6414 This variable is exported by @code{(guix build-system r)}. It
6415 implements the build procedure used by @uref{https://r-project.org, R}
6416 packages, which essentially is little more than running @code{R CMD
6417 INSTALL --library=/gnu/store/@dots{}} in an environment where
6418 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6419 are run after installation using the R function
6420 @code{tools::testInstalledPackage}.
6423 @defvr {Scheme Variable} rakudo-build-system
6424 This variable is exported by @code{(guix build-system rakudo)}. It
6425 implements the build procedure used by @uref{https://rakudo.org/,
6426 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6427 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6428 installs the binaries, library files and the resources, as well as wrap
6429 the files under the @code{bin/} directory. Tests can be skipped by
6430 passing @code{#f} to the @code{tests?} parameter.
6432 Which rakudo package is used can be specified with @code{rakudo}.
6433 Which perl6-tap-harness package used for the tests can be specified with
6434 @code{#:prove6} or removed by passing @code{#f} to the
6435 @code{with-prove6?} parameter.
6436 Which perl6-zef package used for tests and installing can be specified
6437 with @code{#:zef} or removed by passing @code{#f} to the
6438 @code{with-zef?} parameter.
6441 @defvr {Scheme Variable} texlive-build-system
6442 This variable is exported by @code{(guix build-system texlive)}. It is
6443 used to build TeX packages in batch mode with a specified engine. The
6444 build system sets the @code{TEXINPUTS} variable to find all TeX source
6445 files in the inputs.
6447 By default it runs @code{luatex} on all files ending on @code{ins}. A
6448 different engine and format can be specified with the
6449 @code{#:tex-format} argument. Different build targets can be specified
6450 with the @code{#:build-targets} argument, which expects a list of file
6451 names. The build system adds only @code{texlive-bin} and
6452 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6453 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6454 and @code{#:texlive-latex-base}, respectively.
6456 The @code{#:tex-directory} parameter tells the build system where to
6457 install the built files under the texmf tree.
6460 @defvr {Scheme Variable} ruby-build-system
6461 This variable is exported by @code{(guix build-system ruby)}. It
6462 implements the RubyGems build procedure used by Ruby packages, which
6463 involves running @code{gem build} followed by @code{gem install}.
6465 The @code{source} field of a package that uses this build system
6466 typically references a gem archive, since this is the format that Ruby
6467 developers use when releasing their software. The build system unpacks
6468 the gem archive, potentially patches the source, runs the test suite,
6469 repackages the gem, and installs it. Additionally, directories and
6470 tarballs may be referenced to allow building unreleased gems from Git or
6471 a traditional source release tarball.
6473 Which Ruby package is used can be specified with the @code{#:ruby}
6474 parameter. A list of additional flags to be passed to the @command{gem}
6475 command can be specified with the @code{#:gem-flags} parameter.
6478 @defvr {Scheme Variable} waf-build-system
6479 This variable is exported by @code{(guix build-system waf)}. It
6480 implements a build procedure around the @code{waf} script. The common
6481 phases---@code{configure}, @code{build}, and @code{install}---are
6482 implemented by passing their names as arguments to the @code{waf}
6485 The @code{waf} script is executed by the Python interpreter. Which
6486 Python package is used to run the script can be specified with the
6487 @code{#:python} parameter.
6490 @defvr {Scheme Variable} scons-build-system
6491 This variable is exported by @code{(guix build-system scons)}. It
6492 implements the build procedure used by the SCons software construction
6493 tool. This build system runs @code{scons} to build the package,
6494 @code{scons test} to run tests, and then @code{scons install} to install
6497 Additional flags to be passed to @code{scons} can be specified with the
6498 @code{#:scons-flags} parameter. The default build and install targets
6499 can be overridden with @code{#:build-targets} and
6500 @code{#:install-targets} respectively. The version of Python used to
6501 run SCons can be specified by selecting the appropriate SCons package
6502 with the @code{#:scons} parameter.
6505 @defvr {Scheme Variable} haskell-build-system
6506 This variable is exported by @code{(guix build-system haskell)}. It
6507 implements the Cabal build procedure used by Haskell packages, which
6508 involves running @code{runhaskell Setup.hs configure
6509 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6510 Instead of installing the package by running @code{runhaskell Setup.hs
6511 install}, to avoid trying to register libraries in the read-only
6512 compiler store directory, the build system uses @code{runhaskell
6513 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6514 addition, the build system generates the package documentation by
6515 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6516 is passed. Optional Haddock parameters can be passed with the help of
6517 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6518 not found, the build system looks for @code{Setup.lhs} instead.
6520 Which Haskell compiler is used can be specified with the @code{#:haskell}
6521 parameter which defaults to @code{ghc}.
6524 @defvr {Scheme Variable} dub-build-system
6525 This variable is exported by @code{(guix build-system dub)}. It
6526 implements the Dub build procedure used by D packages, which
6527 involves running @code{dub build} and @code{dub run}.
6528 Installation is done by copying the files manually.
6530 Which D compiler is used can be specified with the @code{#:ldc}
6531 parameter which defaults to @code{ldc}.
6534 @defvr {Scheme Variable} emacs-build-system
6535 This variable is exported by @code{(guix build-system emacs)}. It
6536 implements an installation procedure similar to the packaging system
6537 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6539 It first creates the @code{@var{package}-autoloads.el} file, then it
6540 byte compiles all Emacs Lisp files. Differently from the Emacs
6541 packaging system, the Info documentation files are moved to the standard
6542 documentation directory and the @file{dir} file is deleted. Each
6543 package is installed in its own directory under
6544 @file{share/emacs/site-lisp/guix.d}.
6547 @defvr {Scheme Variable} font-build-system
6548 This variable is exported by @code{(guix build-system font)}. It
6549 implements an installation procedure for font packages where upstream
6550 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6551 need to be copied into place. It copies font files to standard
6552 locations in the output directory.
6555 @defvr {Scheme Variable} meson-build-system
6556 This variable is exported by @code{(guix build-system meson)}. It
6557 implements the build procedure for packages that use
6558 @url{https://mesonbuild.com, Meson} as their build system.
6560 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6561 of inputs, and they can be changed with the parameters @code{#:meson}
6562 and @code{#:ninja} if needed. The default Meson is
6563 @code{meson-for-build}, which is special because it doesn't clear the
6564 @code{RUNPATH} of binaries and libraries when they are installed.
6566 This build system is an extension of @var{gnu-build-system}, but with the
6567 following phases changed to some specific for Meson:
6572 The phase runs @code{meson} with the flags specified in
6573 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6574 @code{plain} unless something else is specified in @code{#:build-type}.
6577 The phase runs @code{ninja} to build the package in parallel by default, but
6578 this can be changed with @code{#:parallel-build?}.
6581 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6582 which is @code{"test"} by default.
6585 The phase runs @code{ninja install} and can not be changed.
6588 Apart from that, the build system also adds the following phases:
6593 This phase ensures that all binaries can find the libraries they need.
6594 It searches for required libraries in subdirectories of the package being
6595 built, and adds those to @code{RUNPATH} where needed. It also removes
6596 references to libraries left over from the build phase by
6597 @code{meson-for-build}, such as test dependencies, that aren't actually
6598 required for the program to run.
6600 @item glib-or-gtk-wrap
6601 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6602 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6604 @item glib-or-gtk-compile-schemas
6605 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6606 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6610 @defvr {Scheme Variable} linux-module-build-system
6611 @var{linux-module-build-system} allows building Linux kernel modules.
6613 @cindex build phases
6614 This build system is an extension of @var{gnu-build-system}, but with the
6615 following phases changed:
6620 This phase configures the environment so that the Linux kernel's Makefile
6621 can be used to build the external kernel module.
6624 This phase uses the Linux kernel's Makefile in order to build the external
6628 This phase uses the Linux kernel's Makefile in order to install the external
6632 It is possible and useful to specify the Linux kernel to use for building
6633 the module (in the "arguments" form of a package using the
6634 linux-module-build-system, use the key #:linux to specify it).
6637 @defvr {Scheme Variable} node-build-system
6638 This variable is exported by @code{(guix build-system node)}. It
6639 implements the build procedure used by @uref{http://nodejs.org,
6640 Node.js}, which implements an approximation of the @code{npm install}
6641 command, followed by an @code{npm test} command.
6643 Which Node.js package is used to interpret the @code{npm} commands can
6644 be specified with the @code{#:node} parameter which defaults to
6648 Lastly, for packages that do not need anything as sophisticated, a
6649 ``trivial'' build system is provided. It is trivial in the sense that
6650 it provides basically no support: it does not pull any implicit inputs,
6651 and does not have a notion of build phases.
6653 @defvr {Scheme Variable} trivial-build-system
6654 This variable is exported by @code{(guix build-system trivial)}.
6656 This build system requires a @code{#:builder} argument. This argument
6657 must be a Scheme expression that builds the package output(s)---as
6658 with @code{build-expression->derivation} (@pxref{Derivations,
6659 @code{build-expression->derivation}}).
6669 Conceptually, the @dfn{store} is the place where derivations that have
6670 been built successfully are stored---by default, @file{/gnu/store}.
6671 Sub-directories in the store are referred to as @dfn{store items} or
6672 sometimes @dfn{store paths}. The store has an associated database that
6673 contains information such as the store paths referred to by each store
6674 path, and the list of @emph{valid} store items---results of successful
6675 builds. This database resides in @file{@var{localstatedir}/guix/db},
6676 where @var{localstatedir} is the state directory specified @i{via}
6677 @option{--localstatedir} at configure time, usually @file{/var}.
6679 The store is @emph{always} accessed by the daemon on behalf of its clients
6680 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6681 connect to the daemon over a Unix-domain socket, send requests to it,
6682 and read the result---these are remote procedure calls, or RPCs.
6685 Users must @emph{never} modify files under @file{/gnu/store} directly.
6686 This would lead to inconsistencies and break the immutability
6687 assumptions of Guix's functional model (@pxref{Introduction}).
6689 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6690 how to check the integrity of the store and attempt recovery from
6691 accidental modifications.
6694 The @code{(guix store)} module provides procedures to connect to the
6695 daemon, and to perform RPCs. These are described below. By default,
6696 @code{open-connection}, and thus all the @command{guix} commands,
6697 connect to the local daemon or to the URI specified by the
6698 @code{GUIX_DAEMON_SOCKET} environment variable.
6700 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6701 When set, the value of this variable should be a file name or a URI
6702 designating the daemon endpoint. When it is a file name, it denotes a
6703 Unix-domain socket to connect to. In addition to file names, the
6704 supported URI schemes are:
6709 These are for Unix-domain sockets.
6710 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6711 @file{/var/guix/daemon-socket/socket}.
6714 @cindex daemon, remote access
6715 @cindex remote access to the daemon
6716 @cindex daemon, cluster setup
6717 @cindex clusters, daemon setup
6718 These URIs denote connections over TCP/IP, without encryption nor
6719 authentication of the remote host. The URI must specify the host name
6720 and optionally a port number (by default port 44146 is used):
6723 guix://master.guix.example.org:1234
6726 This setup is suitable on local networks, such as clusters, where only
6727 trusted nodes may connect to the build daemon at
6728 @code{master.guix.example.org}.
6730 The @code{--listen} option of @command{guix-daemon} can be used to
6731 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6735 @cindex SSH access to build daemons
6736 These URIs allow you to connect to a remote daemon over
6737 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6738 A typical URL might look like this:
6741 ssh://charlie@@guix.example.org:22
6744 As for @command{guix copy}, the usual OpenSSH client configuration files
6745 are honored (@pxref{Invoking guix copy}).
6748 Additional URI schemes may be supported in the future.
6750 @c XXX: Remove this note when the protocol incurs fewer round trips
6751 @c and when (guix derivations) no longer relies on file system access.
6753 The ability to connect to remote build daemons is considered
6754 experimental as of @value{VERSION}. Please get in touch with us to
6755 share any problems or suggestions you may have (@pxref{Contributing}).
6759 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6760 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6761 @var{reserve-space?} is true, instruct it to reserve a little bit of
6762 extra space on the file system so that the garbage collector can still
6763 operate should the disk become full. Return a server object.
6765 @var{file} defaults to @code{%default-socket-path}, which is the normal
6766 location given the options that were passed to @command{configure}.
6769 @deffn {Scheme Procedure} close-connection @var{server}
6770 Close the connection to @var{server}.
6773 @defvr {Scheme Variable} current-build-output-port
6774 This variable is bound to a SRFI-39 parameter, which refers to the port
6775 where build and error logs sent by the daemon should be written.
6778 Procedures that make RPCs all take a server object as their first
6781 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6782 @cindex invalid store items
6783 Return @code{#t} when @var{path} designates a valid store item and
6784 @code{#f} otherwise (an invalid item may exist on disk but still be
6785 invalid, for instance because it is the result of an aborted or failed
6788 A @code{&store-protocol-error} condition is raised if @var{path} is not
6789 prefixed by the store directory (@file{/gnu/store}).
6792 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6793 Add @var{text} under file @var{name} in the store, and return its store
6794 path. @var{references} is the list of store paths referred to by the
6795 resulting store path.
6798 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6800 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6801 file names, or derivation/output pairs, using the specified
6802 @var{mode}---@code{(build-mode normal)} by default.
6805 Note that the @code{(guix monads)} module provides a monad as well as
6806 monadic versions of the above procedures, with the goal of making it
6807 more convenient to work with code that accesses the store (@pxref{The
6811 @i{This section is currently incomplete.}
6814 @section Derivations
6817 Low-level build actions and the environment in which they are performed
6818 are represented by @dfn{derivations}. A derivation contains the
6819 following pieces of information:
6823 The outputs of the derivation---derivations produce at least one file or
6824 directory in the store, but may produce more.
6827 @cindex build-time dependencies
6828 @cindex dependencies, build-time
6829 The inputs of the derivations---i.e., its build-time dependencies---which may
6830 be other derivations or plain files in the store (patches, build scripts,
6834 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6837 The file name of a build script in the store, along with the arguments
6841 A list of environment variables to be defined.
6845 @cindex derivation path
6846 Derivations allow clients of the daemon to communicate build actions to
6847 the store. They exist in two forms: as an in-memory representation,
6848 both on the client- and daemon-side, and as files in the store whose
6849 name end in @code{.drv}---these files are referred to as @dfn{derivation
6850 paths}. Derivations paths can be passed to the @code{build-derivations}
6851 procedure to perform the build actions they prescribe (@pxref{The
6854 @cindex fixed-output derivations
6855 Operations such as file downloads and version-control checkouts for
6856 which the expected content hash is known in advance are modeled as
6857 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6858 of a fixed-output derivation are independent of its inputs---e.g., a
6859 source code download produces the same result regardless of the download
6860 method and tools being used.
6863 @cindex run-time dependencies
6864 @cindex dependencies, run-time
6865 The outputs of derivations---i.e., the build results---have a set of
6866 @dfn{references}, as reported by the @code{references} RPC or the
6867 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6868 are the set of run-time dependencies of the build results. References are a
6869 subset of the inputs of the derivation; this subset is automatically computed
6870 by the build daemon by scanning all the files in the outputs.
6872 The @code{(guix derivations)} module provides a representation of
6873 derivations as Scheme objects, along with procedures to create and
6874 otherwise manipulate derivations. The lowest-level primitive to create
6875 a derivation is the @code{derivation} procedure:
6877 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6878 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6879 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6880 [#:system (%current-system)] [#:references-graphs #f] @
6881 [#:allowed-references #f] [#:disallowed-references #f] @
6882 [#:leaked-env-vars #f] [#:local-build? #f] @
6883 [#:substitutable? #t] [#:properties '()]
6884 Build a derivation with the given arguments, and return the resulting
6885 @code{<derivation>} object.
6887 When @var{hash} and @var{hash-algo} are given, a
6888 @dfn{fixed-output derivation} is created---i.e., one whose result is
6889 known in advance, such as a file download. If, in addition,
6890 @var{recursive?} is true, then that fixed output may be an executable
6891 file or a directory and @var{hash} must be the hash of an archive
6892 containing this output.
6894 When @var{references-graphs} is true, it must be a list of file
6895 name/store path pairs. In that case, the reference graph of each store
6896 path is exported in the build environment in the corresponding file, in
6897 a simple text format.
6899 When @var{allowed-references} is true, it must be a list of store items
6900 or outputs that the derivation's output may refer to. Likewise,
6901 @var{disallowed-references}, if true, must be a list of things the
6902 outputs may @emph{not} refer to.
6904 When @var{leaked-env-vars} is true, it must be a list of strings
6905 denoting environment variables that are allowed to ``leak'' from the
6906 daemon's environment to the build environment. This is only applicable
6907 to fixed-output derivations---i.e., when @var{hash} is true. The main
6908 use is to allow variables such as @code{http_proxy} to be passed to
6909 derivations that download files.
6911 When @var{local-build?} is true, declare that the derivation is not a
6912 good candidate for offloading and should rather be built locally
6913 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6914 where the costs of data transfers would outweigh the benefits.
6916 When @var{substitutable?} is false, declare that substitutes of the
6917 derivation's output should not be used (@pxref{Substitutes}). This is
6918 useful, for instance, when building packages that capture details of the
6919 host CPU instruction set.
6921 @var{properties} must be an association list describing ``properties'' of the
6922 derivation. It is kept as-is, uninterpreted, in the derivation.
6926 Here's an example with a shell script as its builder, assuming
6927 @var{store} is an open connection to the daemon, and @var{bash} points
6928 to a Bash executable in the store:
6931 (use-modules (guix utils)
6935 (let ((builder ; add the Bash script to the store
6936 (add-text-to-store store "my-builder.sh"
6937 "echo hello world > $out\n" '())))
6938 (derivation store "foo"
6939 bash `("-e" ,builder)
6940 #:inputs `((,bash) (,builder))
6941 #:env-vars '(("HOME" . "/homeless"))))
6942 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6945 As can be guessed, this primitive is cumbersome to use directly. A
6946 better approach is to write build scripts in Scheme, of course! The
6947 best course of action for that is to write the build code as a
6948 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6949 information, @pxref{G-Expressions}.
6951 Once upon a time, @code{gexp->derivation} did not exist and constructing
6952 derivations with build code written in Scheme was achieved with
6953 @code{build-expression->derivation}, documented below. This procedure
6954 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6956 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6957 @var{name} @var{exp} @
6958 [#:system (%current-system)] [#:inputs '()] @
6959 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6960 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6961 [#:references-graphs #f] [#:allowed-references #f] @
6962 [#:disallowed-references #f] @
6963 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6964 Return a derivation that executes Scheme expression @var{exp} as a
6965 builder for derivation @var{name}. @var{inputs} must be a list of
6966 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6967 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6968 modules from the current search path to be copied in the store,
6969 compiled, and made available in the load path during the execution of
6970 @var{exp}---e.g., @code{((guix build utils) (guix build
6971 gnu-build-system))}.
6973 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6974 to a list of output/path pairs, and where @code{%build-inputs} is bound
6975 to a list of string/output-path pairs made from @var{inputs}.
6976 Optionally, @var{env-vars} is a list of string pairs specifying the name
6977 and value of environment variables visible to the builder. The builder
6978 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6979 @var{exp} returns @code{#f}, the build is considered to have failed.
6981 @var{exp} is built using @var{guile-for-build} (a derivation). When
6982 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6983 @code{%guile-for-build} fluid is used instead.
6985 See the @code{derivation} procedure for the meaning of
6986 @var{references-graphs}, @var{allowed-references},
6987 @var{disallowed-references}, @var{local-build?}, and
6988 @var{substitutable?}.
6992 Here's an example of a single-output derivation that creates a directory
6993 containing one file:
6996 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6997 (mkdir out) ; create /gnu/store/@dots{}-goo
6998 (call-with-output-file (string-append out "/test")
7000 (display '(hello guix) p))))))
7001 (build-expression->derivation store "goo" builder))
7003 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7007 @node The Store Monad
7008 @section The Store Monad
7012 The procedures that operate on the store described in the previous
7013 sections all take an open connection to the build daemon as their first
7014 argument. Although the underlying model is functional, they either have
7015 side effects or depend on the current state of the store.
7017 The former is inconvenient: the connection to the build daemon has to be
7018 carried around in all those functions, making it impossible to compose
7019 functions that do not take that parameter with functions that do. The
7020 latter can be problematic: since store operations have side effects
7021 and/or depend on external state, they have to be properly sequenced.
7023 @cindex monadic values
7024 @cindex monadic functions
7025 This is where the @code{(guix monads)} module comes in. This module
7026 provides a framework for working with @dfn{monads}, and a particularly
7027 useful monad for our uses, the @dfn{store monad}. Monads are a
7028 construct that allows two things: associating ``context'' with values
7029 (in our case, the context is the store), and building sequences of
7030 computations (here computations include accesses to the store). Values
7031 in a monad---values that carry this additional context---are called
7032 @dfn{monadic values}; procedures that return such values are called
7033 @dfn{monadic procedures}.
7035 Consider this ``normal'' procedure:
7038 (define (sh-symlink store)
7039 ;; Return a derivation that symlinks the 'bash' executable.
7040 (let* ((drv (package-derivation store bash))
7041 (out (derivation->output-path drv))
7042 (sh (string-append out "/bin/bash")))
7043 (build-expression->derivation store "sh"
7044 `(symlink ,sh %output))))
7047 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7048 as a monadic function:
7051 (define (sh-symlink)
7052 ;; Same, but return a monadic value.
7053 (mlet %store-monad ((drv (package->derivation bash)))
7054 (gexp->derivation "sh"
7055 #~(symlink (string-append #$drv "/bin/bash")
7059 There are several things to note in the second version: the @code{store}
7060 parameter is now implicit and is ``threaded'' in the calls to the
7061 @code{package->derivation} and @code{gexp->derivation} monadic
7062 procedures, and the monadic value returned by @code{package->derivation}
7063 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7065 As it turns out, the call to @code{package->derivation} can even be
7066 omitted since it will take place implicitly, as we will see later
7067 (@pxref{G-Expressions}):
7070 (define (sh-symlink)
7071 (gexp->derivation "sh"
7072 #~(symlink (string-append #$bash "/bin/bash")
7077 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7078 @c for the funny quote.
7079 Calling the monadic @code{sh-symlink} has no effect. As someone once
7080 said, ``you exit a monad like you exit a building on fire: by running''.
7081 So, to exit the monad and get the desired effect, one must use
7082 @code{run-with-store}:
7085 (run-with-store (open-connection) (sh-symlink))
7086 @result{} /gnu/store/...-sh-symlink
7089 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7090 new ``meta-commands'' to make it easier to deal with monadic procedures:
7091 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7092 to ``run'' a single monadic value through the store:
7095 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7096 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7099 The latter enters a recursive REPL, where all the return values are
7100 automatically run through the store:
7103 scheme@@(guile-user)> ,enter-store-monad
7104 store-monad@@(guile-user) [1]> (package->derivation hello)
7105 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7106 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7107 $3 = "/gnu/store/@dots{}-foo"
7108 store-monad@@(guile-user) [1]> ,q
7109 scheme@@(guile-user)>
7113 Note that non-monadic values cannot be returned in the
7114 @code{store-monad} REPL.
7116 The main syntactic forms to deal with monads in general are provided by
7117 the @code{(guix monads)} module and are described below.
7119 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7120 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7124 @deffn {Scheme Syntax} return @var{val}
7125 Return a monadic value that encapsulates @var{val}.
7128 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7129 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7130 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7131 referred to as ``bind'', but that name denotes an unrelated procedure in
7132 Guile. Thus we use this somewhat cryptic symbol inherited from the
7133 Haskell language.}. There can be one @var{mproc} or several of them, as
7138 (with-monad %state-monad
7140 (lambda (x) (return (+ 1 x)))
7141 (lambda (x) (return (* 2 x)))))
7145 @result{} some-state
7149 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7151 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7153 Bind the variables @var{var} to the monadic values @var{mval} in
7154 @var{body}, which is a sequence of expressions. As with the bind
7155 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7156 value ``contained'' in @var{mval} and making @var{var} refer to that
7157 raw, non-monadic value within the scope of the @var{body}. The form
7158 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7159 @var{val}, as per @code{let}. The binding operations occur in sequence
7160 from left to right. The last expression of @var{body} must be a monadic
7161 expression, and its result will become the result of the @code{mlet} or
7162 @code{mlet*} when run in the @var{monad}.
7164 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7165 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7168 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7169 Bind @var{mexp} and the following monadic expressions in sequence,
7170 returning the result of the last expression. Every expression in the
7171 sequence must be a monadic expression.
7173 This is akin to @code{mlet}, except that the return values of the
7174 monadic expressions are ignored. In that sense, it is analogous to
7175 @code{begin}, but applied to monadic expressions.
7178 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7179 When @var{condition} is true, evaluate the sequence of monadic
7180 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7181 @var{condition} is false, return @code{*unspecified*} in the current
7182 monad. Every expression in the sequence must be a monadic expression.
7185 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7186 When @var{condition} is false, evaluate the sequence of monadic
7187 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7188 @var{condition} is true, return @code{*unspecified*} in the current
7189 monad. Every expression in the sequence must be a monadic expression.
7193 The @code{(guix monads)} module provides the @dfn{state monad}, which
7194 allows an additional value---the state---to be @emph{threaded} through
7195 monadic procedure calls.
7197 @defvr {Scheme Variable} %state-monad
7198 The state monad. Procedures in the state monad can access and change
7199 the state that is threaded.
7201 Consider the example below. The @code{square} procedure returns a value
7202 in the state monad. It returns the square of its argument, but also
7203 increments the current state value:
7207 (mlet %state-monad ((count (current-state)))
7208 (mbegin %state-monad
7209 (set-current-state (+ 1 count))
7212 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7217 When ``run'' through @var{%state-monad}, we obtain that additional state
7218 value, which is the number of @code{square} calls.
7221 @deffn {Monadic Procedure} current-state
7222 Return the current state as a monadic value.
7225 @deffn {Monadic Procedure} set-current-state @var{value}
7226 Set the current state to @var{value} and return the previous state as a
7230 @deffn {Monadic Procedure} state-push @var{value}
7231 Push @var{value} to the current state, which is assumed to be a list,
7232 and return the previous state as a monadic value.
7235 @deffn {Monadic Procedure} state-pop
7236 Pop a value from the current state and return it as a monadic value.
7237 The state is assumed to be a list.
7240 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7241 Run monadic value @var{mval} starting with @var{state} as the initial
7242 state. Return two values: the resulting value, and the resulting state.
7245 The main interface to the store monad, provided by the @code{(guix
7246 store)} module, is as follows.
7248 @defvr {Scheme Variable} %store-monad
7249 The store monad---an alias for @var{%state-monad}.
7251 Values in the store monad encapsulate accesses to the store. When its
7252 effect is needed, a value of the store monad must be ``evaluated'' by
7253 passing it to the @code{run-with-store} procedure (see below.)
7256 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7257 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7258 open store connection.
7261 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7262 Return as a monadic value the absolute file name in the store of the file
7263 containing @var{text}, a string. @var{references} is a list of store items that the
7264 resulting text file refers to; it defaults to the empty list.
7267 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7268 Return as a monadic value the absolute file name in the store of the file
7269 containing @var{data}, a bytevector. @var{references} is a list of store
7270 items that the resulting binary file refers to; it defaults to the empty list.
7273 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7274 [#:recursive? #t] [#:select? (const #t)]
7275 Return the name of @var{file} once interned in the store. Use
7276 @var{name} as its store name, or the basename of @var{file} if
7277 @var{name} is omitted.
7279 When @var{recursive?} is true, the contents of @var{file} are added
7280 recursively; if @var{file} designates a flat file and @var{recursive?}
7281 is true, its contents are added, and its permission bits are kept.
7283 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7284 @var{stat})} for each directory entry, where @var{file} is the entry's
7285 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7286 entries for which @var{select?} does not return true.
7288 The example below adds a file to the store, under two different names:
7291 (run-with-store (open-connection)
7292 (mlet %store-monad ((a (interned-file "README"))
7293 (b (interned-file "README" "LEGU-MIN")))
7294 (return (list a b))))
7296 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7301 The @code{(guix packages)} module exports the following package-related
7304 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7305 [#:system (%current-system)] [#:target #f] @
7308 value in the absolute file name of @var{file} within the @var{output}
7309 directory of @var{package}. When @var{file} is omitted, return the name
7310 of the @var{output} directory of @var{package}. When @var{target} is
7311 true, use it as a cross-compilation target triplet.
7314 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7315 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7316 @var{target} [@var{system}]
7317 Monadic version of @code{package-derivation} and
7318 @code{package-cross-derivation} (@pxref{Defining Packages}).
7323 @section G-Expressions
7325 @cindex G-expression
7326 @cindex build code quoting
7327 So we have ``derivations'', which represent a sequence of build actions
7328 to be performed to produce an item in the store (@pxref{Derivations}).
7329 These build actions are performed when asking the daemon to actually
7330 build the derivations; they are run by the daemon in a container
7331 (@pxref{Invoking guix-daemon}).
7333 @cindex strata of code
7334 It should come as no surprise that we like to write these build actions
7335 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7336 code@footnote{The term @dfn{stratum} in this context was coined by
7337 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7338 Kiselyov, who has written insightful
7339 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7340 on this topic}, refers to this kind of code generation as
7341 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7342 to the daemon, etc.---and the ``build code''---code that actually
7343 performs build actions, such as making directories, invoking
7344 @command{make}, etc.
7346 To describe a derivation and its build actions, one typically needs to
7347 embed build code inside host code. It boils down to manipulating build
7348 code as data, and the homoiconicity of Scheme---code has a direct
7349 representation as data---comes in handy for that. But we need more than
7350 the normal @code{quasiquote} mechanism in Scheme to construct build
7353 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7354 S-expressions adapted to build expressions. G-expressions, or
7355 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7356 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7357 @code{#$}, and @code{#$@@}), which are comparable to
7358 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7359 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7360 GNU Guile Reference Manual}). However, there are major differences:
7364 Gexps are meant to be written to a file and run or manipulated by other
7368 When a high-level object such as a package or derivation is unquoted
7369 inside a gexp, the result is as if its output file name had been
7373 Gexps carry information about the packages or derivations they refer to,
7374 and these dependencies are automatically added as inputs to the build
7375 processes that use them.
7378 @cindex lowering, of high-level objects in gexps
7379 This mechanism is not limited to package and derivation
7380 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7381 derivations or files in the store can be defined,
7382 such that these objects can also be inserted
7383 into gexps. For example, a useful type of high-level objects that can be
7384 inserted in a gexp is ``file-like objects'', which make it easy to
7385 add files to the store and to refer to them in
7386 derivations and such (see @code{local-file} and @code{plain-file}
7389 To illustrate the idea, here is an example of a gexp:
7396 (symlink (string-append #$coreutils "/bin/ls")
7400 This gexp can be passed to @code{gexp->derivation}; we obtain a
7401 derivation that builds a directory containing exactly one symlink to
7402 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7405 (gexp->derivation "the-thing" build-exp)
7408 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7409 substituted to the reference to the @var{coreutils} package in the
7410 actual build code, and @var{coreutils} is automatically made an input to
7411 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7412 output)}) is replaced by a string containing the directory name of the
7413 output of the derivation.
7415 @cindex cross compilation
7416 In a cross-compilation context, it is useful to distinguish between
7417 references to the @emph{native} build of a package---that can run on the
7418 host---versus references to cross builds of a package. To that end, the
7419 @code{#+} plays the same role as @code{#$}, but is a reference to a
7420 native package build:
7423 (gexp->derivation "vi"
7426 (system* (string-append #+coreutils "/bin/ln")
7428 (string-append #$emacs "/bin/emacs")
7429 (string-append #$output "/bin/vi")))
7430 #:target "mips64el-linux-gnu")
7434 In the example above, the native build of @var{coreutils} is used, so
7435 that @command{ln} can actually run on the host; but then the
7436 cross-compiled build of @var{emacs} is referenced.
7438 @cindex imported modules, for gexps
7439 @findex with-imported-modules
7440 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7441 able to use certain Guile modules from the ``host environment'' in the
7442 gexp, so those modules should be imported in the ``build environment''.
7443 The @code{with-imported-modules} form allows you to express that:
7446 (let ((build (with-imported-modules '((guix build utils))
7448 (use-modules (guix build utils))
7449 (mkdir-p (string-append #$output "/bin"))))))
7450 (gexp->derivation "empty-dir"
7453 (display "success!\n")
7458 In this example, the @code{(guix build utils)} module is automatically
7459 pulled into the isolated build environment of our gexp, such that
7460 @code{(use-modules (guix build utils))} works as expected.
7462 @cindex module closure
7463 @findex source-module-closure
7464 Usually you want the @emph{closure} of the module to be imported---i.e.,
7465 the module itself and all the modules it depends on---rather than just
7466 the module; failing to do that, attempts to use the module will fail
7467 because of missing dependent modules. The @code{source-module-closure}
7468 procedure computes the closure of a module by looking at its source file
7469 headers, which comes in handy in this case:
7472 (use-modules (guix modules)) ;for 'source-module-closure'
7474 (with-imported-modules (source-module-closure
7475 '((guix build utils)
7477 (gexp->derivation "something-with-vms"
7479 (use-modules (guix build utils)
7484 @cindex extensions, for gexps
7485 @findex with-extensions
7486 In the same vein, sometimes you want to import not just pure-Scheme
7487 modules, but also ``extensions'' such as Guile bindings to C libraries
7488 or other ``full-blown'' packages. Say you need the @code{guile-json}
7489 package available on the build side, here's how you would do it:
7492 (use-modules (gnu packages guile)) ;for 'guile-json'
7494 (with-extensions (list guile-json)
7495 (gexp->derivation "something-with-json"
7497 (use-modules (json))
7501 The syntactic form to construct gexps is summarized below.
7503 @deffn {Scheme Syntax} #~@var{exp}
7504 @deffnx {Scheme Syntax} (gexp @var{exp})
7505 Return a G-expression containing @var{exp}. @var{exp} may contain one
7506 or more of the following forms:
7510 @itemx (ungexp @var{obj})
7511 Introduce a reference to @var{obj}. @var{obj} may have one of the
7512 supported types, for example a package or a
7513 derivation, in which case the @code{ungexp} form is replaced by its
7514 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7516 If @var{obj} is a list, it is traversed and references to supported
7517 objects are substituted similarly.
7519 If @var{obj} is another gexp, its contents are inserted and its
7520 dependencies are added to those of the containing gexp.
7522 If @var{obj} is another kind of object, it is inserted as is.
7524 @item #$@var{obj}:@var{output}
7525 @itemx (ungexp @var{obj} @var{output})
7526 This is like the form above, but referring explicitly to the
7527 @var{output} of @var{obj}---this is useful when @var{obj} produces
7528 multiple outputs (@pxref{Packages with Multiple Outputs}).
7531 @itemx #+@var{obj}:output
7532 @itemx (ungexp-native @var{obj})
7533 @itemx (ungexp-native @var{obj} @var{output})
7534 Same as @code{ungexp}, but produces a reference to the @emph{native}
7535 build of @var{obj} when used in a cross compilation context.
7537 @item #$output[:@var{output}]
7538 @itemx (ungexp output [@var{output}])
7539 Insert a reference to derivation output @var{output}, or to the main
7540 output when @var{output} is omitted.
7542 This only makes sense for gexps passed to @code{gexp->derivation}.
7545 @itemx (ungexp-splicing @var{lst})
7546 Like the above, but splices the contents of @var{lst} inside the
7550 @itemx (ungexp-native-splicing @var{lst})
7551 Like the above, but refers to native builds of the objects listed in
7556 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7557 of the @code{gexp?} type (see below.)
7560 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7561 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7562 in their execution environment.
7564 Each item in @var{modules} can be the name of a module, such as
7565 @code{(guix build utils)}, or it can be a module name, followed by an
7566 arrow, followed by a file-like object:
7569 `((guix build utils)
7571 ((guix config) => ,(scheme-file "config.scm"
7572 #~(define-module @dots{}))))
7576 In the example above, the first two modules are taken from the search
7577 path, and the last one is created from the given file-like object.
7579 This form has @emph{lexical} scope: it has an effect on the gexps
7580 directly defined in @var{body}@dots{}, but not on those defined, say, in
7581 procedures called from @var{body}@dots{}.
7584 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7585 Mark the gexps defined in @var{body}@dots{} as requiring
7586 @var{extensions} in their build and execution environment.
7587 @var{extensions} is typically a list of package objects such as those
7588 defined in the @code{(gnu packages guile)} module.
7590 Concretely, the packages listed in @var{extensions} are added to the
7591 load path while compiling imported modules in @var{body}@dots{}; they
7592 are also added to the load path of the gexp returned by
7596 @deffn {Scheme Procedure} gexp? @var{obj}
7597 Return @code{#t} if @var{obj} is a G-expression.
7600 G-expressions are meant to be written to disk, either as code building
7601 some derivation, or as plain files in the store. The monadic procedures
7602 below allow you to do that (@pxref{The Store Monad}, for more
7603 information about monads.)
7605 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7606 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7607 [#:hash #f] [#:hash-algo #f] @
7608 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7609 [#:module-path @var{%load-path}] @
7610 [#:effective-version "2.2"] @
7611 [#:references-graphs #f] [#:allowed-references #f] @
7612 [#:disallowed-references #f] @
7613 [#:leaked-env-vars #f] @
7614 [#:script-name (string-append @var{name} "-builder")] @
7615 [#:deprecation-warnings #f] @
7616 [#:local-build? #f] [#:substitutable? #t] @
7617 [#:properties '()] [#:guile-for-build #f]
7618 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7619 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7620 stored in a file called @var{script-name}. When @var{target} is true,
7621 it is used as the cross-compilation target triplet for packages referred
7624 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7626 make @var{modules} available in the evaluation context of @var{exp};
7627 @var{modules} is a list of names of Guile modules searched in
7628 @var{module-path} to be copied in the store, compiled, and made available in
7629 the load path during the execution of @var{exp}---e.g., @code{((guix
7630 build utils) (guix build gnu-build-system))}.
7632 @var{effective-version} determines the string to use when adding extensions of
7633 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7635 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7638 When @var{references-graphs} is true, it must be a list of tuples of one of the
7642 (@var{file-name} @var{package})
7643 (@var{file-name} @var{package} @var{output})
7644 (@var{file-name} @var{derivation})
7645 (@var{file-name} @var{derivation} @var{output})
7646 (@var{file-name} @var{store-item})
7649 The right-hand-side of each element of @var{references-graphs} is automatically made
7650 an input of the build process of @var{exp}. In the build environment, each
7651 @var{file-name} contains the reference graph of the corresponding item, in a simple
7654 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7655 In the latter case, the list denotes store items that the result is allowed to
7656 refer to. Any reference to another store item will lead to a build error.
7657 Similarly for @var{disallowed-references}, which can list items that must not be
7658 referenced by the outputs.
7660 @var{deprecation-warnings} determines whether to show deprecation warnings while
7661 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7663 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7666 @cindex file-like objects
7667 The @code{local-file}, @code{plain-file}, @code{computed-file},
7668 @code{program-file}, and @code{scheme-file} procedures below return
7669 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7670 these objects lead to a file in the store. Consider this G-expression:
7673 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7674 #$(local-file "/tmp/my-nscd.conf"))
7677 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7678 to the store. Once expanded, for instance @i{via}
7679 @code{gexp->derivation}, the G-expression refers to that copy under
7680 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7681 does not have any effect on what the G-expression does.
7682 @code{plain-file} can be used similarly; it differs in that the file
7683 content is directly passed as a string.
7685 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7686 [#:recursive? #f] [#:select? (const #t)]
7687 Return an object representing local file @var{file} to add to the store; this
7688 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7689 up relative to the source file where this form appears. @var{file} will be added to
7690 the store under @var{name}--by default the base name of @var{file}.
7692 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7693 designates a flat file and @var{recursive?} is true, its contents are added, and its
7694 permission bits are kept.
7696 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7697 @var{stat})} for each directory entry, where @var{file} is the entry's
7698 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7699 entries for which @var{select?} does not return true.
7701 This is the declarative counterpart of the @code{interned-file} monadic
7702 procedure (@pxref{The Store Monad, @code{interned-file}}).
7705 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7706 Return an object representing a text file called @var{name} with the given
7707 @var{content} (a string or a bytevector) to be added to the store.
7709 This is the declarative counterpart of @code{text-file}.
7712 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7713 [#:options '(#:local-build? #t)]
7714 Return an object representing the store item @var{name}, a file or
7715 directory computed by @var{gexp}. @var{options}
7716 is a list of additional arguments to pass to @code{gexp->derivation}.
7718 This is the declarative counterpart of @code{gexp->derivation}.
7721 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7722 [#:guile (default-guile)] [#:module-path %load-path] @
7723 [#:system (%current-system)] [#:target #f]
7724 Return an executable script @var{name} that runs @var{exp} using
7725 @var{guile}, with @var{exp}'s imported modules in its search path.
7726 Look up @var{exp}'s modules in @var{module-path}.
7728 The example below builds a script that simply invokes the @command{ls}
7732 (use-modules (guix gexp) (gnu packages base))
7734 (gexp->script "list-files"
7735 #~(execl #$(file-append coreutils "/bin/ls")
7739 When ``running'' it through the store (@pxref{The Store Monad,
7740 @code{run-with-store}}), we obtain a derivation that produces an
7741 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7744 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7746 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7750 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7751 [#:guile #f] [#:module-path %load-path]
7752 Return an object representing the executable store item @var{name} that
7753 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7754 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7756 This is the declarative counterpart of @code{gexp->script}.
7759 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7760 [#:set-load-path? #t] [#:module-path %load-path] @
7762 [#:guile (default-guile)]
7763 Return a derivation that builds a file @var{name} containing @var{exp}.
7764 When @var{splice?} is true, @var{exp} is considered to be a list of
7765 expressions that will be spliced in the resulting file.
7767 When @var{set-load-path?} is true, emit code in the resulting file to
7768 set @code{%load-path} and @code{%load-compiled-path} to honor
7769 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7772 The resulting file holds references to all the dependencies of @var{exp}
7773 or a subset thereof.
7776 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7777 Return an object representing the Scheme file @var{name} that contains
7780 This is the declarative counterpart of @code{gexp->file}.
7783 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7784 Return as a monadic value a derivation that builds a text file
7785 containing all of @var{text}. @var{text} may list, in addition to
7786 strings, objects of any type that can be used in a gexp: packages,
7787 derivations, local file objects, etc. The resulting store file holds
7788 references to all these.
7790 This variant should be preferred over @code{text-file} anytime the file
7791 to create will reference items from the store. This is typically the
7792 case when building a configuration file that embeds store file names,
7796 (define (profile.sh)
7797 ;; Return the name of a shell script in the store that
7798 ;; initializes the 'PATH' environment variable.
7799 (text-file* "profile.sh"
7800 "export PATH=" coreutils "/bin:"
7801 grep "/bin:" sed "/bin\n"))
7804 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7805 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7806 preventing them from being garbage-collected during its lifetime.
7809 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7810 Return an object representing store file @var{name} containing
7811 @var{text}. @var{text} is a sequence of strings and file-like objects,
7815 (mixed-text-file "profile"
7816 "export PATH=" coreutils "/bin:" grep "/bin")
7819 This is the declarative counterpart of @code{text-file*}.
7822 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7823 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7824 Each item in @var{files} must be a two-element list where the first element is the
7825 file name to use in the new directory, and the second element is a gexp
7826 denoting the target file. Here's an example:
7830 `(("hosts" ,(plain-file "hosts"
7831 "127.0.0.1 localhost"))
7832 ("bashrc" ,(plain-file "bashrc"
7833 "alias ls='ls --color=auto'"))))
7836 This yields an @code{etc} directory containing these two files.
7839 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7840 Return a directory that is the union of @var{things}, where @var{things} is a list of
7841 file-like objects denoting directories. For example:
7844 (directory-union "guile+emacs" (list guile emacs))
7847 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7850 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7851 Return a file-like object that expands to the concatenation of @var{obj}
7852 and @var{suffix}, where @var{obj} is a lowerable object and each
7853 @var{suffix} is a string.
7855 As an example, consider this gexp:
7858 (gexp->script "run-uname"
7859 #~(system* #$(file-append coreutils
7863 The same effect could be achieved with:
7866 (gexp->script "run-uname"
7867 #~(system* (string-append #$coreutils
7871 There is one difference though: in the @code{file-append} case, the
7872 resulting script contains the absolute file name as a string, whereas in
7873 the second case, the resulting script contains a @code{(string-append
7874 @dots{})} expression to construct the file name @emph{at run time}.
7878 Of course, in addition to gexps embedded in ``host'' code, there are
7879 also modules containing build tools. To make it clear that they are
7880 meant to be used in the build stratum, these modules are kept in the
7881 @code{(guix build @dots{})} name space.
7883 @cindex lowering, of high-level objects in gexps
7884 Internally, high-level objects are @dfn{lowered}, using their compiler,
7885 to either derivations or store items. For instance, lowering a package
7886 yields a derivation, and lowering a @code{plain-file} yields a store
7887 item. This is achieved using the @code{lower-object} monadic procedure.
7889 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7891 Return as a value in @var{%store-monad} the derivation or store item
7892 corresponding to @var{obj} for @var{system}, cross-compiling for
7893 @var{target} if @var{target} is true. @var{obj} must be an object that
7894 has an associated gexp compiler, such as a @code{<package>}.
7897 @node Invoking guix repl
7898 @section Invoking @command{guix repl}
7900 @cindex REPL, read-eval-print loop
7901 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7902 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7903 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7904 command, @command{guix repl} guarantees that all the Guix modules and all its
7905 dependencies are available in the search path. You can use it this way:
7909 scheme@@(guile-user)> ,use (gnu packages base)
7910 scheme@@(guile-user)> coreutils
7911 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7915 In addition, @command{guix repl} implements a simple machine-readable REPL
7916 protocol for use by @code{(guix inferior)}, a facility to interact with
7917 @dfn{inferiors}, separate processes running a potentially different revision
7920 The available options are as follows:
7923 @item --type=@var{type}
7924 @itemx -t @var{type}
7925 Start a REPL of the given @var{TYPE}, which can be one of the following:
7929 This is default, and it spawns a standard full-featured Guile REPL.
7931 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7932 that the @code{(guix inferior)} module speaks.
7935 @item --listen=@var{endpoint}
7936 By default, @command{guix repl} reads from standard input and writes to
7937 standard output. When this option is passed, it will instead listen for
7938 connections on @var{endpoint}. Here are examples of valid options:
7941 @item --listen=tcp:37146
7942 Accept connections on localhost on port 37146.
7944 @item --listen=unix:/tmp/socket
7945 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7949 @c *********************************************************************
7953 This section describes Guix command-line utilities. Some of them are
7954 primarily targeted at developers and users who write new package
7955 definitions, while others are more generally useful. They complement
7956 the Scheme programming interface of Guix in a convenient way.
7959 * Invoking guix build:: Building packages from the command line.
7960 * Invoking guix edit:: Editing package definitions.
7961 * Invoking guix download:: Downloading a file and printing its hash.
7962 * Invoking guix hash:: Computing the cryptographic hash of a file.
7963 * Invoking guix import:: Importing package definitions.
7964 * Invoking guix refresh:: Updating package definitions.
7965 * Invoking guix lint:: Finding errors in package definitions.
7966 * Invoking guix size:: Profiling disk usage.
7967 * Invoking guix graph:: Visualizing the graph of packages.
7968 * Invoking guix publish:: Sharing substitutes.
7969 * Invoking guix challenge:: Challenging substitute servers.
7970 * Invoking guix copy:: Copying to and from a remote store.
7971 * Invoking guix container:: Process isolation.
7972 * Invoking guix weather:: Assessing substitute availability.
7973 * Invoking guix processes:: Listing client processes.
7976 @node Invoking guix build
7977 @section Invoking @command{guix build}
7979 @cindex package building
7980 @cindex @command{guix build}
7981 The @command{guix build} command builds packages or derivations and
7982 their dependencies, and prints the resulting store paths. Note that it
7983 does not modify the user's profile---this is the job of the
7984 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7985 it is mainly useful for distribution developers.
7987 The general syntax is:
7990 guix build @var{options} @var{package-or-derivation}@dots{}
7993 As an example, the following command builds the latest versions of Emacs
7994 and of Guile, displays their build logs, and finally displays the
7995 resulting directories:
7998 guix build emacs guile
8001 Similarly, the following command builds all the available packages:
8004 guix build --quiet --keep-going \
8005 `guix package -A | cut -f1,2 --output-delimiter=@@`
8008 @var{package-or-derivation} may be either the name of a package found in
8009 the software distribution such as @code{coreutils} or
8010 @code{coreutils@@8.20}, or a derivation such as
8011 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8012 package with the corresponding name (and optionally version) is searched
8013 for among the GNU distribution modules (@pxref{Package Modules}).
8015 Alternatively, the @code{--expression} option may be used to specify a
8016 Scheme expression that evaluates to a package; this is useful when
8017 disambiguating among several same-named packages or package variants is
8020 There may be zero or more @var{options}. The available options are
8021 described in the subsections below.
8024 * Common Build Options:: Build options for most commands.
8025 * Package Transformation Options:: Creating variants of packages.
8026 * Additional Build Options:: Options specific to 'guix build'.
8027 * Debugging Build Failures:: Real life packaging experience.
8030 @node Common Build Options
8031 @subsection Common Build Options
8033 A number of options that control the build process are common to
8034 @command{guix build} and other commands that can spawn builds, such as
8035 @command{guix package} or @command{guix archive}. These are the
8040 @item --load-path=@var{directory}
8041 @itemx -L @var{directory}
8042 Add @var{directory} to the front of the package module search path
8043 (@pxref{Package Modules}).
8045 This allows users to define their own packages and make them visible to
8046 the command-line tools.
8050 Keep the build tree of failed builds. Thus, if a build fails, its build
8051 tree is kept under @file{/tmp}, in a directory whose name is shown at
8052 the end of the build log. This is useful when debugging build issues.
8053 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8056 This option implies @option{--no-offload}, and it has no effect when
8057 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8058 Store, the @code{GUIX_DAEMON_SOCKET} variable}).
8062 Keep going when some of the derivations fail to build; return only once
8063 all the builds have either completed or failed.
8065 The default behavior is to stop as soon as one of the specified
8066 derivations has failed.
8070 Do not build the derivations.
8072 @anchor{fallback-option}
8074 When substituting a pre-built binary fails, fall back to building
8075 packages locally (@pxref{Substitution Failure}).
8077 @item --substitute-urls=@var{urls}
8078 @anchor{client-substitute-urls}
8079 Consider @var{urls} the whitespace-separated list of substitute source
8080 URLs, overriding the default list of URLs of @command{guix-daemon}
8081 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8083 This means that substitutes may be downloaded from @var{urls}, provided
8084 they are signed by a key authorized by the system administrator
8085 (@pxref{Substitutes}).
8087 When @var{urls} is the empty string, substitutes are effectively
8090 @item --no-substitutes
8091 Do not use substitutes for build products. That is, always build things
8092 locally instead of allowing downloads of pre-built binaries
8093 (@pxref{Substitutes}).
8096 Do not ``graft'' packages. In practice, this means that package updates
8097 available as grafts are not applied. @xref{Security Updates}, for more
8098 information on grafts.
8100 @item --rounds=@var{n}
8101 Build each derivation @var{n} times in a row, and raise an error if
8102 consecutive build results are not bit-for-bit identical.
8104 This is a useful way to detect non-deterministic builds processes.
8105 Non-deterministic build processes are a problem because they make it
8106 practically impossible for users to @emph{verify} whether third-party
8107 binaries are genuine. @xref{Invoking guix challenge}, for more.
8109 Note that, currently, the differing build results are not kept around,
8110 so you will have to manually investigate in case of an error---e.g., by
8111 stashing one of the build results with @code{guix archive --export}
8112 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8116 Do not use offload builds to other machines (@pxref{Daemon Offload
8117 Setup}). That is, always build things locally instead of offloading
8118 builds to remote machines.
8120 @item --max-silent-time=@var{seconds}
8121 When the build or substitution process remains silent for more than
8122 @var{seconds}, terminate it and report a build failure.
8124 By default, the daemon's setting is honored (@pxref{Invoking
8125 guix-daemon, @code{--max-silent-time}}).
8127 @item --timeout=@var{seconds}
8128 Likewise, when the build or substitution process lasts for more than
8129 @var{seconds}, terminate it and report a build failure.
8131 By default, the daemon's setting is honored (@pxref{Invoking
8132 guix-daemon, @code{--timeout}}).
8134 @c Note: This option is actually not part of %standard-build-options but
8135 @c most programs honor it.
8136 @cindex verbosity, of the command-line tools
8137 @cindex build logs, verbosity
8138 @item -v @var{level}
8139 @itemx --verbosity=@var{level}
8140 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8141 output is produced, 1 is for quiet output, and 2 shows all the build log
8142 output on standard error.
8144 @item --cores=@var{n}
8146 Allow the use of up to @var{n} CPU cores for the build. The special
8147 value @code{0} means to use as many CPU cores as available.
8149 @item --max-jobs=@var{n}
8151 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8152 guix-daemon, @code{--max-jobs}}, for details about this option and the
8153 equivalent @command{guix-daemon} option.
8155 @item --debug=@var{level}
8156 Produce debugging output coming from the build daemon. @var{level} must be an
8157 integer between 0 and 5; higher means more verbose output. Setting a level of
8158 4 or more may be helpful when debugging setup issues with the build daemon.
8162 Behind the scenes, @command{guix build} is essentially an interface to
8163 the @code{package-derivation} procedure of the @code{(guix packages)}
8164 module, and to the @code{build-derivations} procedure of the @code{(guix
8165 derivations)} module.
8167 In addition to options explicitly passed on the command line,
8168 @command{guix build} and other @command{guix} commands that support
8169 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
8171 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8172 Users can define this variable to a list of command line options that
8173 will automatically be used by @command{guix build} and other
8174 @command{guix} commands that can perform builds, as in the example
8178 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8181 These options are parsed independently, and the result is appended to
8182 the parsed command-line options.
8186 @node Package Transformation Options
8187 @subsection Package Transformation Options
8189 @cindex package variants
8190 Another set of command-line options supported by @command{guix build}
8191 and also @command{guix package} are @dfn{package transformation
8192 options}. These are options that make it possible to define @dfn{package
8193 variants}---for instance, packages built from different source code.
8194 This is a convenient way to create customized packages on the fly
8195 without having to type in the definitions of package variants
8196 (@pxref{Defining Packages}).
8200 @item --with-source=@var{source}
8201 @itemx --with-source=@var{package}=@var{source}
8202 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8203 Use @var{source} as the source of @var{package}, and @var{version} as
8205 @var{source} must be a file name or a URL, as for @command{guix
8206 download} (@pxref{Invoking guix download}).
8208 When @var{package} is omitted,
8209 it is taken to be the package name specified on the
8210 command line that matches the base of @var{source}---e.g.,
8211 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8212 package is @code{guile}.
8214 Likewise, when @var{version} is omitted, the version string is inferred from
8215 @var{source}; in the previous example, it is @code{2.0.10}.
8217 This option allows users to try out versions of packages other than the
8218 one provided by the distribution. The example below downloads
8219 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8220 the @code{ed} package:
8223 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8226 As a developer, @code{--with-source} makes it easy to test release
8230 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8233 @dots{} or to build from a checkout in a pristine environment:
8236 $ git clone git://git.sv.gnu.org/guix.git
8237 $ guix build guix --with-source=guix@@1.0=./guix
8240 @item --with-input=@var{package}=@var{replacement}
8241 Replace dependency on @var{package} by a dependency on
8242 @var{replacement}. @var{package} must be a package name, and
8243 @var{replacement} must be a package specification such as @code{guile}
8244 or @code{guile@@1.8}.
8246 For instance, the following command builds Guix, but replaces its
8247 dependency on the current stable version of Guile with a dependency on
8248 the legacy version of Guile, @code{guile@@2.0}:
8251 guix build --with-input=guile=guile@@2.0 guix
8254 This is a recursive, deep replacement. So in this example, both
8255 @code{guix} and its dependency @code{guile-json} (which also depends on
8256 @code{guile}) get rebuilt against @code{guile@@2.0}.
8258 This is implemented using the @code{package-input-rewriting} Scheme
8259 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8261 @item --with-graft=@var{package}=@var{replacement}
8262 This is similar to @code{--with-input} but with an important difference:
8263 instead of rebuilding the whole dependency chain, @var{replacement} is
8264 built and then @dfn{grafted} onto the binaries that were initially
8265 referring to @var{package}. @xref{Security Updates}, for more
8266 information on grafts.
8268 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8269 and all its dependencies, replacing references to the version of GnuTLS
8270 they currently refer to:
8273 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8276 This has the advantage of being much faster than rebuilding everything.
8277 But there is a caveat: it works if and only if @var{package} and
8278 @var{replacement} are strictly compatible---for example, if they provide
8279 a library, the application binary interface (ABI) of those libraries
8280 must be compatible. If @var{replacement} is somehow incompatible with
8281 @var{package}, then the resulting package may be unusable. Use with
8284 @item --with-git-url=@var{package}=@var{url}
8285 @cindex Git, using the latest commit
8286 @cindex latest commit, building
8287 Build @var{package} from the latest commit of the @code{master} branch of the
8288 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8291 For example, the following command builds the NumPy Python library against the
8292 latest commit of the master branch of Python itself:
8295 guix build python-numpy \
8296 --with-git-url=python=https://github.com/python/cpython
8299 This option can also be combined with @code{--with-branch} or
8300 @code{--with-commit} (see below).
8302 @cindex continuous integration
8303 Obviously, since it uses the latest commit of the given branch, the result of
8304 such a command varies over time. Nevertheless it is a convenient way to
8305 rebuild entire software stacks against the latest commit of one or more
8306 packages. This is particularly useful in the context of continuous
8309 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8310 consecutive accesses to the same repository. You may want to clean it up once
8311 in a while to save disk space.
8313 @item --with-branch=@var{package}=@var{branch}
8314 Build @var{package} from the latest commit of @var{branch}. If the
8315 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8316 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8317 repository URL is taken from that @code{source}. Otherwise you have to use
8318 @code{--with-git-url} to specify the URL of the Git repository.
8320 For instance, the following command builds @code{guile-sqlite3} from the
8321 latest commit of its @code{master} branch, and then builds @code{guix} (which
8322 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8323 specific @code{guile-sqlite3} build:
8326 guix build --with-branch=guile-sqlite3=master cuirass
8329 @item --with-commit=@var{package}=@var{commit}
8330 This is similar to @code{--with-branch}, except that it builds from
8331 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8332 Git commit SHA1 identifier or a tag.
8335 @node Additional Build Options
8336 @subsection Additional Build Options
8338 The command-line options presented below are specific to @command{guix
8345 Build quietly, without displaying the build log; this is equivalent to
8346 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8347 (or similar) and can always be retrieved using the @option{--log-file} option.
8349 @item --file=@var{file}
8350 @itemx -f @var{file}
8351 Build the package, derivation, or other file-like object that the code within
8352 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8354 As an example, @var{file} might contain a package definition like this
8355 (@pxref{Defining Packages}):
8358 @include package-hello.scm
8361 @item --expression=@var{expr}
8362 @itemx -e @var{expr}
8363 Build the package or derivation @var{expr} evaluates to.
8365 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8366 guile-1.8)}, which unambiguously designates this specific variant of
8367 version 1.8 of Guile.
8369 Alternatively, @var{expr} may be a G-expression, in which case it is used
8370 as a build program passed to @code{gexp->derivation}
8371 (@pxref{G-Expressions}).
8373 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8374 (@pxref{The Store Monad}). The procedure must return a derivation as a
8375 monadic value, which is then passed through @code{run-with-store}.
8379 Build the source derivations of the packages, rather than the packages
8382 For instance, @code{guix build -S gcc} returns something like
8383 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8386 The returned source tarball is the result of applying any patches and
8387 code snippets specified in the package @code{origin} (@pxref{Defining
8390 Note that @command{guix build -S} compiles the sources only of the
8391 specified packages. They do not include the sources of statically
8392 linked dependencies and by themselves are insufficient for reproducing
8396 Fetch and return the source of @var{package-or-derivation} and all their
8397 dependencies, recursively. This is a handy way to obtain a local copy
8398 of all the source code needed to build @var{packages}, allowing you to
8399 eventually build them even without network access. It is an extension
8400 of the @code{--source} option and can accept one of the following
8401 optional argument values:
8405 This value causes the @code{--sources} option to behave in the same way
8406 as the @code{--source} option.
8409 Build the source derivations of all packages, including any source that
8410 might be listed as @code{inputs}. This is the default value.
8413 $ guix build --sources tzdata
8414 The following derivations will be built:
8415 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8416 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8420 Build the source derivations of all packages, as well of all transitive
8421 inputs to the packages. This can be used e.g.@: to
8422 prefetch package source for later offline building.
8425 $ guix build --sources=transitive tzdata
8426 The following derivations will be built:
8427 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8428 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8429 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8430 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8431 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8432 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8438 @item --system=@var{system}
8439 @itemx -s @var{system}
8440 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8441 the system type of the build host. The @command{guix build} command allows
8442 you to repeat this option several times, in which case it builds for all the
8443 specified systems; other commands ignore extraneous @option{-s} options.
8446 The @code{--system} flag is for @emph{native} compilation and must not
8447 be confused with cross-compilation. See @code{--target} below for
8448 information on cross-compilation.
8451 An example use of this is on Linux-based systems, which can emulate
8452 different personalities. For instance, passing
8453 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8454 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8455 to build packages in a complete 32-bit environment.
8458 Building for an @code{armhf-linux} system is unconditionally enabled on
8459 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8460 allow for this functionality, notably the ThunderX.
8463 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8464 is enabled (@pxref{Virtualization Services,
8465 @code{qemu-binfmt-service-type}}), you can build for any system for
8466 which a QEMU @code{binfmt_misc} handler is installed.
8468 Builds for a system other than that of the machine you are using can
8469 also be offloaded to a remote machine of the right architecture.
8470 @xref{Daemon Offload Setup}, for more information on offloading.
8472 @item --target=@var{triplet}
8473 @cindex cross-compilation
8474 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8475 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8476 configuration triplets,, autoconf, Autoconf}).
8478 @anchor{build-check}
8480 @cindex determinism, checking
8481 @cindex reproducibility, checking
8482 Rebuild @var{package-or-derivation}, which are already available in the
8483 store, and raise an error if the build results are not bit-for-bit
8486 This mechanism allows you to check whether previously installed
8487 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8488 of a package is deterministic. @xref{Invoking guix challenge}, for more
8489 background information and tools.
8491 When used in conjunction with @option{--keep-failed}, the differing
8492 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8493 This makes it easy to look for differences between the two results.
8496 @cindex repairing store items
8497 @cindex corruption, recovering from
8498 Attempt to repair the specified store items, if they are corrupt, by
8499 re-downloading or rebuilding them.
8501 This operation is not atomic and thus restricted to @code{root}.
8505 Return the derivation paths, not the output paths, of the given
8508 @item --root=@var{file}
8509 @itemx -r @var{file}
8510 @cindex GC roots, adding
8511 @cindex garbage collector roots, adding
8512 Make @var{file} a symlink to the result, and register it as a garbage
8515 Consequently, the results of this @command{guix build} invocation are
8516 protected from garbage collection until @var{file} is removed. When
8517 that option is omitted, build results are eligible for garbage
8518 collection as soon as the build completes. @xref{Invoking guix gc}, for
8522 @cindex build logs, access
8523 Return the build log file names or URLs for the given
8524 @var{package-or-derivation}, or raise an error if build logs are
8527 This works regardless of how packages or derivations are specified. For
8528 instance, the following invocations are equivalent:
8531 guix build --log-file `guix build -d guile`
8532 guix build --log-file `guix build guile`
8533 guix build --log-file guile
8534 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8537 If a log is unavailable locally, and unless @code{--no-substitutes} is
8538 passed, the command looks for a corresponding log on one of the
8539 substitute servers (as specified with @code{--substitute-urls}.)
8541 So for instance, imagine you want to see the build log of GDB on MIPS,
8542 but you are actually on an @code{x86_64} machine:
8545 $ guix build --log-file gdb -s mips64el-linux
8546 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8549 You can freely access a huge library of build logs!
8552 @node Debugging Build Failures
8553 @subsection Debugging Build Failures
8555 @cindex build failures, debugging
8556 When defining a new package (@pxref{Defining Packages}), you will
8557 probably find yourself spending some time debugging and tweaking the
8558 build until it succeeds. To do that, you need to operate the build
8559 commands yourself in an environment as close as possible to the one the
8562 To that end, the first thing to do is to use the @option{--keep-failed}
8563 or @option{-K} option of @command{guix build}, which will keep the
8564 failed build tree in @file{/tmp} or whatever directory you specified as
8565 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8567 From there on, you can @command{cd} to the failed build tree and source
8568 the @file{environment-variables} file, which contains all the
8569 environment variable definitions that were in place when the build
8570 failed. So let's say you're debugging a build failure in package
8571 @code{foo}; a typical session would look like this:
8575 @dots{} @i{build fails}
8576 $ cd /tmp/guix-build-foo.drv-0
8577 $ source ./environment-variables
8581 Now, you can invoke commands as if you were the daemon (almost) and
8582 troubleshoot your build process.
8584 Sometimes it happens that, for example, a package's tests pass when you
8585 run them manually but they fail when the daemon runs them. This can
8586 happen because the daemon runs builds in containers where, unlike in our
8587 environment above, network access is missing, @file{/bin/sh} does not
8588 exist, etc. (@pxref{Build Environment Setup}).
8590 In such cases, you may need to run inspect the build process from within
8591 a container similar to the one the build daemon creates:
8596 $ cd /tmp/guix-build-foo.drv-0
8597 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8598 [env]# source ./environment-variables
8602 Here, @command{guix environment -C} creates a container and spawns a new
8603 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8604 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8605 the container, which would may find handy while debugging. The
8606 @option{--no-grafts} option makes sure we get the exact same
8607 environment, with ungrafted packages (@pxref{Security Updates}, for more
8610 To get closer to a container like that used by the build daemon, we can
8611 remove @file{/bin/sh}:
8617 (Don't worry, this is harmless: this is all happening in the throw-away
8618 container created by @command{guix environment}.)
8620 The @command{strace} command is probably not in the search path, but we
8624 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8627 In this way, not only you will have reproduced the environment variables
8628 the daemon uses, you will also be running the build process in a container
8629 similar to the one the daemon uses.
8632 @node Invoking guix edit
8633 @section Invoking @command{guix edit}
8635 @cindex @command{guix edit}
8636 @cindex package definition, editing
8637 So many packages, so many source files! The @command{guix edit} command
8638 facilitates the life of users and packagers by pointing their editor at
8639 the source file containing the definition of the specified packages.
8643 guix edit gcc@@4.9 vim
8647 launches the program specified in the @code{VISUAL} or in the
8648 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8651 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8652 have created your own packages on @code{GUIX_PACKAGE_PATH}
8653 (@pxref{Package Modules}), you will be able to edit the package
8654 recipes. In other cases, you will be able to examine the read-only recipes
8655 for packages currently in the store.
8658 @node Invoking guix download
8659 @section Invoking @command{guix download}
8661 @cindex @command{guix download}
8662 @cindex downloading package sources
8663 When writing a package definition, developers typically need to download
8664 a source tarball, compute its SHA256 hash, and write that
8665 hash in the package definition (@pxref{Defining Packages}). The
8666 @command{guix download} tool helps with this task: it downloads a file
8667 from the given URI, adds it to the store, and prints both its file name
8668 in the store and its SHA256 hash.
8670 The fact that the downloaded file is added to the store saves bandwidth:
8671 when the developer eventually tries to build the newly defined package
8672 with @command{guix build}, the source tarball will not have to be
8673 downloaded again because it is already in the store. It is also a
8674 convenient way to temporarily stash files, which may be deleted
8675 eventually (@pxref{Invoking guix gc}).
8677 The @command{guix download} command supports the same URIs as used in
8678 package definitions. In particular, it supports @code{mirror://} URIs.
8679 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8680 Guile bindings for GnuTLS are available in the user's environment; when
8681 they are not available, an error is raised. @xref{Guile Preparations,
8682 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8683 GnuTLS-Guile}, for more information.
8685 @command{guix download} verifies HTTPS server certificates by loading
8686 the certificates of X.509 authorities from the directory pointed to by
8687 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8688 Certificates}), unless @option{--no-check-certificate} is used.
8690 The following options are available:
8693 @item --format=@var{fmt}
8695 Write the hash in the format specified by @var{fmt}. For more
8696 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8698 @item --no-check-certificate
8699 Do not validate the X.509 certificates of HTTPS servers.
8701 When using this option, you have @emph{absolutely no guarantee} that you
8702 are communicating with the authentic server responsible for the given
8703 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8705 @item --output=@var{file}
8706 @itemx -o @var{file}
8707 Save the downloaded file to @var{file} instead of adding it to the
8711 @node Invoking guix hash
8712 @section Invoking @command{guix hash}
8714 @cindex @command{guix hash}
8715 The @command{guix hash} command computes the SHA256 hash of a file.
8716 It is primarily a convenience tool for anyone contributing to the
8717 distribution: it computes the cryptographic hash of a file, which can be
8718 used in the definition of a package (@pxref{Defining Packages}).
8720 The general syntax is:
8723 guix hash @var{option} @var{file}
8726 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8727 hash of data read from standard input. @command{guix hash} has the
8732 @item --format=@var{fmt}
8734 Write the hash in the format specified by @var{fmt}.
8736 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8737 (@code{hex} and @code{hexadecimal} can be used as well).
8739 If the @option{--format} option is not specified, @command{guix hash}
8740 will output the hash in @code{nix-base32}. This representation is used
8741 in the definitions of packages.
8745 Compute the hash on @var{file} recursively.
8747 In this case, the hash is computed on an archive containing @var{file},
8748 including its children if it is a directory. Some of the metadata of
8749 @var{file} is part of the archive; for instance, when @var{file} is a
8750 regular file, the hash is different depending on whether @var{file} is
8751 executable or not. Metadata such as time stamps has no impact on the
8752 hash (@pxref{Invoking guix archive}).
8753 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8758 When combined with @option{--recursive}, exclude version control system
8759 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8762 As an example, here is how you would compute the hash of a Git checkout,
8763 which is useful when using the @code{git-fetch} method (@pxref{origin
8767 $ git clone http://example.org/foo.git
8773 @node Invoking guix import
8774 @section Invoking @command{guix import}
8776 @cindex importing packages
8777 @cindex package import
8778 @cindex package conversion
8779 @cindex Invoking @command{guix import}
8780 The @command{guix import} command is useful for people who would like to
8781 add a package to the distribution with as little work as
8782 possible---a legitimate demand. The command knows of a few
8783 repositories from which it can ``import'' package metadata. The result
8784 is a package definition, or a template thereof, in the format we know
8785 (@pxref{Defining Packages}).
8787 The general syntax is:
8790 guix import @var{importer} @var{options}@dots{}
8793 @var{importer} specifies the source from which to import package
8794 metadata, and @var{options} specifies a package identifier and other
8795 options specific to @var{importer}.
8797 Some of the importers rely on the ability to run the @command{gpgv} command.
8798 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
8801 Currently, the available ``importers'' are:
8805 Import metadata for the given GNU package. This provides a template
8806 for the latest version of that GNU package, including the hash of its
8807 source tarball, and its canonical synopsis and description.
8809 Additional information such as the package dependencies and its
8810 license needs to be figured out manually.
8812 For example, the following command returns a package definition for
8816 guix import gnu hello
8819 Specific command-line options are:
8822 @item --key-download=@var{policy}
8823 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8824 keys when verifying the package signature. @xref{Invoking guix
8825 refresh, @code{--key-download}}.
8830 Import metadata from the @uref{https://pypi.python.org/, Python Package
8831 Index}. Information is taken from the JSON-formatted description
8832 available at @code{pypi.python.org} and usually includes all the relevant
8833 information, including package dependencies. For maximum efficiency, it
8834 is recommended to install the @command{unzip} utility, so that the
8835 importer can unzip Python wheels and gather data from them.
8837 The command below imports metadata for the @code{itsdangerous} Python
8841 guix import pypi itsdangerous
8847 Traverse the dependency graph of the given upstream package recursively
8848 and generate package expressions for all those packages that are not yet
8854 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8855 is taken from the JSON-formatted description available at
8856 @code{rubygems.org} and includes most relevant information, including
8857 runtime dependencies. There are some caveats, however. The metadata
8858 doesn't distinguish between synopses and descriptions, so the same string
8859 is used for both fields. Additionally, the details of non-Ruby
8860 dependencies required to build native extensions is unavailable and left
8861 as an exercise to the packager.
8863 The command below imports metadata for the @code{rails} Ruby package:
8866 guix import gem rails
8872 Traverse the dependency graph of the given upstream package recursively
8873 and generate package expressions for all those packages that are not yet
8879 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8880 Information is taken from the JSON-formatted metadata provided through
8881 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8882 relevant information, such as module dependencies. License information
8883 should be checked closely. If Perl is available in the store, then the
8884 @code{corelist} utility will be used to filter core modules out of the
8885 list of dependencies.
8887 The command command below imports metadata for the @code{Acme::Boolean}
8891 guix import cpan Acme::Boolean
8896 @cindex Bioconductor
8897 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8898 central repository for the @uref{https://r-project.org, GNU@tie{}R
8899 statistical and graphical environment}.
8901 Information is extracted from the @code{DESCRIPTION} file of the package.
8903 The command command below imports metadata for the @code{Cairo}
8907 guix import cran Cairo
8910 When @code{--recursive} is added, the importer will traverse the
8911 dependency graph of the given upstream package recursively and generate
8912 package expressions for all those packages that are not yet in Guix.
8914 When @code{--archive=bioconductor} is added, metadata is imported from
8915 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8916 packages for for the analysis and comprehension of high-throughput
8917 genomic data in bioinformatics.
8919 Information is extracted from the @code{DESCRIPTION} file contained in the
8922 The command below imports metadata for the @code{GenomicRanges}
8926 guix import cran --archive=bioconductor GenomicRanges
8929 Finally, you can also import R packages that have not yet been published on
8930 CRAN or Bioconductor as long as they are in a git repository. Use
8931 @code{--archive=git} followed by the URL of the git repository:
8934 guix import cran --archive=git https://github.com/immunogenomics/harmony
8940 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8941 comprehensive TeX archive network for TeX packages that are part of the
8942 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8944 Information about the package is obtained through the XML API provided
8945 by CTAN, while the source code is downloaded from the SVN repository of
8946 the Tex Live project. This is done because the CTAN does not keep
8949 The command command below imports metadata for the @code{fontspec}
8953 guix import texlive fontspec
8956 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8957 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8958 tree in the TeX Live SVN repository, but from the specified sibling
8959 directory under the same root.
8961 The command below imports metadata for the @code{ifxetex} package from
8962 CTAN while fetching the sources from the directory
8963 @file{texmf/source/generic}:
8966 guix import texlive --archive=generic ifxetex
8970 @cindex JSON, import
8971 Import package metadata from a local JSON file. Consider the following
8972 example package definition in JSON format:
8978 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8979 "build-system": "gnu",
8980 "home-page": "https://www.gnu.org/software/hello/",
8981 "synopsis": "Hello, GNU world: An example GNU package",
8982 "description": "GNU Hello prints a greeting.",
8983 "license": "GPL-3.0+",
8984 "native-inputs": ["gettext"]
8988 The field names are the same as for the @code{<package>} record
8989 (@xref{Defining Packages}). References to other packages are provided
8990 as JSON lists of quoted package specification strings such as
8991 @code{guile} or @code{guile@@2.0}.
8993 The importer also supports a more explicit source definition using the
8994 common fields for @code{<origin>} records:
9000 "method": "url-fetch",
9001 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9003 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9010 The command below reads metadata from the JSON file @code{hello.json}
9011 and outputs a package expression:
9014 guix import json hello.json
9018 Import metadata from a local copy of the source of the
9019 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9020 relies on the @command{nix-instantiate} command of
9021 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9022 typically written in a mixture of Nix-language and Bash code. This
9023 command only imports the high-level package structure that is written in
9024 the Nix language. It normally includes all the basic fields of a
9027 When importing a GNU package, the synopsis and descriptions are replaced
9028 by their canonical upstream variant.
9030 Usually, you will first need to do:
9033 export NIX_REMOTE=daemon
9037 so that @command{nix-instantiate} does not try to open the Nix database.
9039 As an example, the command below imports the package definition of
9040 LibreOffice (more precisely, it imports the definition of the package
9041 bound to the @code{libreoffice} top-level attribute):
9044 guix import nix ~/path/to/nixpkgs libreoffice
9049 Import metadata from the Haskell community's central package archive
9050 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9051 Cabal files and includes all the relevant information, including package
9054 Specific command-line options are:
9059 Read a Cabal file from standard input.
9060 @item --no-test-dependencies
9062 Do not include dependencies required only by the test suites.
9063 @item --cabal-environment=@var{alist}
9064 @itemx -e @var{alist}
9065 @var{alist} is a Scheme alist defining the environment in which the
9066 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9067 @code{arch}, @code{impl} and a string representing the name of a flag.
9068 The value associated with a flag has to be either the symbol
9069 @code{true} or @code{false}. The value associated with other keys
9070 has to conform to the Cabal file format definition. The default value
9071 associated with the keys @code{os}, @code{arch} and @code{impl} is
9072 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9075 Traverse the dependency graph of the given upstream package recursively
9076 and generate package expressions for all those packages that are not yet
9080 The command below imports metadata for the latest version of the
9081 @code{HTTP} Haskell package without including test dependencies and
9082 specifying the value of the flag @samp{network-uri} as @code{false}:
9085 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9088 A specific package version may optionally be specified by following the
9089 package name by an at-sign and a version number as in the following example:
9092 guix import hackage mtl@@2.1.3.1
9097 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9098 It takes a package name, looks up the package version included in a
9099 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9100 release and uses the @code{hackage} importer to retrieve its metadata.
9101 Note that it is up to you to select an LTS release compatible with the
9102 GHC compiler used by Guix.
9104 Specific command-line options are:
9107 @item --no-test-dependencies
9109 Do not include dependencies required only by the test suites.
9110 @item --lts-version=@var{version}
9111 @itemx -l @var{version}
9112 @var{version} is the desired LTS release version. If omitted the latest
9116 Traverse the dependency graph of the given upstream package recursively
9117 and generate package expressions for all those packages that are not yet
9121 The command below imports metadata for the @code{HTTP} Haskell package
9122 included in the LTS Stackage release version 7.18:
9125 guix import stackage --lts-version=7.18 HTTP
9130 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9131 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9133 Specific command-line options are:
9136 @item --archive=@var{repo}
9137 @itemx -a @var{repo}
9138 @var{repo} identifies the archive repository from which to retrieve the
9139 information. Currently the supported repositories and their identifiers
9143 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9144 identifier. This is the default.
9146 Packages from @code{elpa.gnu.org} are signed with one of the keys
9147 contained in the GnuPG keyring at
9148 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9149 @code{emacs} package (@pxref{Package Installation, ELPA package
9150 signatures,, emacs, The GNU Emacs Manual}).
9153 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9154 @code{melpa-stable} identifier.
9157 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9163 Traverse the dependency graph of the given upstream package recursively
9164 and generate package expressions for all those packages that are not yet
9170 Import metadata from the crates.io Rust package repository
9171 @uref{https://crates.io, crates.io}, as in this example:
9174 guix import crate blake2-rfc
9177 The crate importer also allows you to specify a version string:
9180 guix import crate constant-time-eq@@0.1.0
9183 Additional options include:
9188 Traverse the dependency graph of the given upstream package recursively
9189 and generate package expressions for all those packages that are not yet
9196 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9197 repository used by the OCaml community.
9200 The structure of the @command{guix import} code is modular. It would be
9201 useful to have more importers for other package formats, and your help
9202 is welcome here (@pxref{Contributing}).
9204 @node Invoking guix refresh
9205 @section Invoking @command{guix refresh}
9207 @cindex @command {guix refresh}
9208 The primary audience of the @command{guix refresh} command is developers
9209 of the GNU software distribution. By default, it reports any packages
9210 provided by the distribution that are outdated compared to the latest
9211 upstream version, like this:
9215 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9216 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9219 Alternately, one can specify packages to consider, in which case a
9220 warning is emitted for packages that lack an updater:
9223 $ guix refresh coreutils guile guile-ssh
9224 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9225 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9228 @command{guix refresh} browses the upstream repository of each package and determines
9229 the highest version number of the releases therein. The command
9230 knows how to update specific types of packages: GNU packages, ELPA
9231 packages, etc.---see the documentation for @option{--type} below. There
9232 are many packages, though, for which it lacks a method to determine
9233 whether a new upstream release is available. However, the mechanism is
9234 extensible, so feel free to get in touch with us to add a new method!
9239 Consider the packages specified, and all the packages upon which they depend.
9242 $ guix refresh --recursive coreutils
9243 gnu/packages/acl.scm:35:2: warning: no updater for acl
9244 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9245 gnu/packages/xml.scm:68:2: warning: no updater for expat
9246 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9252 Sometimes the upstream name differs from the package name used in Guix,
9253 and @command{guix refresh} needs a little help. Most updaters honor the
9254 @code{upstream-name} property in package definitions, which can be used
9258 (define-public network-manager
9260 (name "network-manager")
9262 (properties '((upstream-name . "NetworkManager")))))
9265 When passed @code{--update}, it modifies distribution source files to
9266 update the version numbers and source tarball hashes of those package
9267 recipes (@pxref{Defining Packages}). This is achieved by downloading
9268 each package's latest source tarball and its associated OpenPGP
9269 signature, authenticating the downloaded tarball against its signature
9270 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9271 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9274 key used to sign the tarball is missing from the user's keyring, an
9275 attempt is made to automatically retrieve it from a public key server;
9276 when this is successful, the key is added to the user's keyring; otherwise,
9277 @command{guix refresh} reports an error.
9279 The following options are supported:
9283 @item --expression=@var{expr}
9284 @itemx -e @var{expr}
9285 Consider the package @var{expr} evaluates to.
9287 This is useful to precisely refer to a package, as in this example:
9290 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9293 This command lists the dependents of the ``final'' libc (essentially all
9298 Update distribution source files (package recipes) in place. This is
9299 usually run from a checkout of the Guix source tree (@pxref{Running
9300 Guix Before It Is Installed}):
9303 $ ./pre-inst-env guix refresh -s non-core -u
9306 @xref{Defining Packages}, for more information on package definitions.
9308 @item --select=[@var{subset}]
9309 @itemx -s @var{subset}
9310 Select all the packages in @var{subset}, one of @code{core} or
9313 The @code{core} subset refers to all the packages at the core of the
9314 distribution---i.e., packages that are used to build ``everything
9315 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9316 changing one of these packages in the distribution entails a rebuild of
9317 all the others. Thus, such updates are an inconvenience to users in
9318 terms of build time or bandwidth used to achieve the upgrade.
9320 The @code{non-core} subset refers to the remaining packages. It is
9321 typically useful in cases where an update of the core packages would be
9324 @item --manifest=@var{file}
9325 @itemx -m @var{file}
9326 Select all the packages from the manifest in @var{file}. This is useful to
9327 check if any packages of the user manifest can be updated.
9329 @item --type=@var{updater}
9330 @itemx -t @var{updater}
9331 Select only packages handled by @var{updater} (may be a comma-separated
9332 list of updaters). Currently, @var{updater} may be one of:
9336 the updater for GNU packages;
9338 the updater for GNOME packages;
9340 the updater for KDE packages;
9342 the updater for X.org packages;
9344 the updater for packages hosted on kernel.org;
9346 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9348 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9350 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9352 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9354 the updater for @uref{https://pypi.python.org, PyPI} packages.
9356 the updater for @uref{https://rubygems.org, RubyGems} packages.
9358 the updater for @uref{https://github.com, GitHub} packages.
9360 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9362 the updater for @uref{https://www.stackage.org, Stackage} packages.
9364 the updater for @uref{https://crates.io, Crates} packages.
9366 the updater for @uref{https://launchpad.net, Launchpad} packages.
9369 For instance, the following command only checks for updates of Emacs
9370 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9373 $ guix refresh --type=elpa,cran
9374 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9375 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9380 In addition, @command{guix refresh} can be passed one or more package
9381 names, as in this example:
9384 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9388 The command above specifically updates the @code{emacs} and
9389 @code{idutils} packages. The @code{--select} option would have no
9390 effect in this case.
9392 When considering whether to upgrade a package, it is sometimes
9393 convenient to know which packages would be affected by the upgrade and
9394 should be checked for compatibility. For this the following option may
9395 be used when passing @command{guix refresh} one or more package names:
9399 @item --list-updaters
9401 List available updaters and exit (see @option{--type} above.)
9403 For each updater, display the fraction of packages it covers; at the
9404 end, display the fraction of packages covered by all these updaters.
9406 @item --list-dependent
9408 List top-level dependent packages that would need to be rebuilt as a
9409 result of upgrading one or more packages.
9411 @xref{Invoking guix graph, the @code{reverse-package} type of
9412 @command{guix graph}}, for information on how to visualize the list of
9413 dependents of a package.
9417 Be aware that the @code{--list-dependent} option only
9418 @emph{approximates} the rebuilds that would be required as a result of
9419 an upgrade. More rebuilds might be required under some circumstances.
9422 $ guix refresh --list-dependent flex
9423 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9424 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9427 The command above lists a set of packages that could be built to check
9428 for compatibility with an upgraded @code{flex} package.
9432 @item --list-transitive
9433 List all the packages which one or more packages depend upon.
9436 $ guix refresh --list-transitive flex
9437 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9438 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{}
9443 The command above lists a set of packages which, when changed, would cause
9444 @code{flex} to be rebuilt.
9446 The following options can be used to customize GnuPG operation:
9450 @item --gpg=@var{command}
9451 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9452 for in @code{$PATH}.
9454 @item --keyring=@var{file}
9455 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9456 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9457 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9458 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9459 information on a tool to manipulate keybox files).
9461 When this option is omitted, @command{guix refresh} uses
9462 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9463 signing keys. OpenPGP signatures are checked against keys from this keyring;
9464 missing keys are downloaded to this keyring as well (see
9465 @option{--key-download} below.)
9467 You can export keys from your default GPG keyring into a keybox file using
9468 commands like this one:
9471 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9474 Likewise, you can fetch keys to a specific keybox file like this:
9477 gpg --no-default-keyring --keyring mykeyring.kbx \
9478 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9481 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9482 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9484 @item --key-download=@var{policy}
9485 Handle missing OpenPGP keys according to @var{policy}, which may be one
9490 Always download missing OpenPGP keys from the key server, and add them
9491 to the user's GnuPG keyring.
9494 Never try to download missing OpenPGP keys. Instead just bail out.
9497 When a package signed with an unknown OpenPGP key is encountered, ask
9498 the user whether to download it or not. This is the default behavior.
9501 @item --key-server=@var{host}
9502 Use @var{host} as the OpenPGP key server when importing a public key.
9506 The @code{github} updater uses the
9507 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9508 releases. When used repeatedly e.g.@: when refreshing all packages,
9509 GitHub will eventually refuse to answer any further API requests. By
9510 default 60 API requests per hour are allowed, and a full refresh on all
9511 GitHub packages in Guix requires more than this. Authentication with
9512 GitHub through the use of an API token alleviates these limits. To use
9513 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9514 token procured from @uref{https://github.com/settings/tokens} or
9518 @node Invoking guix lint
9519 @section Invoking @command{guix lint}
9521 @cindex @command{guix lint}
9522 @cindex package, checking for errors
9523 The @command{guix lint} command is meant to help package developers avoid
9524 common errors and use a consistent style. It runs a number of checks on
9525 a given set of packages in order to find common mistakes in their
9526 definitions. Available @dfn{checkers} include (see
9527 @code{--list-checkers} for a complete list):
9532 Validate certain typographical and stylistic rules about package
9533 descriptions and synopses.
9535 @item inputs-should-be-native
9536 Identify inputs that should most likely be native inputs.
9542 @itemx source-file-name
9543 Probe @code{home-page} and @code{source} URLs and report those that are
9544 invalid. Suggest a @code{mirror://} URL when applicable. If the
9545 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9546 URL. Check that the source file name is meaningful, e.g.@: is not just a
9547 version number or ``git-checkout'', without a declared @code{file-name}
9548 (@pxref{origin Reference}).
9550 @item source-unstable-tarball
9551 Parse the @code{source} URL to determine if a tarball from GitHub is
9552 autogenerated or if it is a release tarball. Unfortunately GitHub's
9553 autogenerated tarballs are sometimes regenerated.
9556 @cindex Software Heritage, source code archive
9557 @cindex archival of source code, Software Heritage
9558 Checks whether the package's source code is archived at
9559 @uref{https://www.softwareheritage.org, Software Heritage}.
9561 When the source code that is not archived comes from a version-control system
9562 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
9563 ``save'' request so that it eventually archives it. This ensures that the
9564 source will remain available in the long term, and that Guix can fall back to
9565 Software Heritage should the source code disappear from its original host.
9566 The status of recent ``save'' requests can be
9567 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
9569 When source code is a tarball obtained with @code{url-fetch}, simply print a
9570 message when it is not archived. As of this writing, Software Heritage does
9571 not allow requests to save arbitrary tarballs; we are working on ways to
9572 ensure that non-VCS source code is also archived.
9575 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
9576 request rate per IP address}. When the limit is reached, @command{guix lint}
9577 prints a message and the @code{archival} checker stops doing anything until
9578 that limit has been reset.
9581 @cindex security vulnerabilities
9582 @cindex CVE, Common Vulnerabilities and Exposures
9583 Report known vulnerabilities found in the Common Vulnerabilities and
9584 Exposures (CVE) databases of the current and past year
9585 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
9588 To view information about a particular vulnerability, visit pages such as:
9592 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9594 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9598 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9599 @code{CVE-2015-7554}.
9601 Package developers can specify in package recipes the
9602 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
9603 name and version of the package when they differ from the name or version
9604 that Guix uses, as in this example:
9610 ;; CPE calls this package "grub2".
9611 (properties '((cpe-name . "grub2")
9612 (cpe-version . "2.3"))))
9615 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9616 Some entries in the CVE database do not specify which version of a
9617 package they apply to, and would thus ``stick around'' forever. Package
9618 developers who found CVE alerts and verified they can be ignored can
9619 declare them as in this example:
9625 ;; These CVEs no longer apply and can be safely ignored.
9626 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9629 "CVE-2011-5244")))))
9633 Warn about obvious source code formatting issues: trailing white space,
9634 use of tabulations, etc.
9637 The general syntax is:
9640 guix lint @var{options} @var{package}@dots{}
9643 If no package is given on the command line, then all packages are checked.
9644 The @var{options} may be zero or more of the following:
9647 @item --list-checkers
9649 List and describe all the available checkers that will be run on packages
9654 Only enable the checkers specified in a comma-separated list using the
9655 names returned by @code{--list-checkers}.
9659 @node Invoking guix size
9660 @section Invoking @command{guix size}
9663 @cindex package size
9665 @cindex @command{guix size}
9666 The @command{guix size} command helps package developers profile the
9667 disk usage of packages. It is easy to overlook the impact of an
9668 additional dependency added to a package, or the impact of using a
9669 single output for a package that could easily be split (@pxref{Packages
9670 with Multiple Outputs}). Such are the typical issues that
9671 @command{guix size} can highlight.
9673 The command can be passed one or more package specifications
9674 such as @code{gcc@@4.8}
9675 or @code{guile:debug}, or a file name in the store. Consider this
9679 $ guix size coreutils
9680 store item total self
9681 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9682 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9683 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9684 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9685 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9686 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9687 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9688 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9693 The store items listed here constitute the @dfn{transitive closure} of
9694 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9695 would be returned by:
9698 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9701 Here the output shows three columns next to store items. The first column,
9702 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9703 the store item---that is, its own size plus the size of all its
9704 dependencies. The next column, labeled ``self'', shows the size of the
9705 item itself. The last column shows the ratio of the size of the item
9706 itself to the space occupied by all the items listed here.
9708 In this example, we see that the closure of Coreutils weighs in at
9709 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9710 libraries. (That libc and GCC's libraries represent a large fraction of
9711 the closure is not a problem @i{per se} because they are always available
9712 on the system anyway.)
9714 When the package(s) passed to @command{guix size} are available in the
9715 store@footnote{More precisely, @command{guix size} looks for the
9716 @emph{ungrafted} variant of the given package(s), as returned by
9717 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9718 for information on grafts.}, @command{guix size} queries the daemon to determine its
9719 dependencies, and measures its size in the store, similar to @command{du
9720 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9723 When the given packages are @emph{not} in the store, @command{guix size}
9724 reports information based on the available substitutes
9725 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9726 store items that are not even on disk, only available remotely.
9728 You can also specify several package names:
9731 $ guix size coreutils grep sed bash
9732 store item total self
9733 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9734 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9735 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9736 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9742 In this example we see that the combination of the four packages takes
9743 102.3@tie{}MiB in total, which is much less than the sum of each closure
9744 since they have a lot of dependencies in common.
9746 The available options are:
9750 @item --substitute-urls=@var{urls}
9751 Use substitute information from @var{urls}.
9752 @xref{client-substitute-urls, the same option for @code{guix build}}.
9754 @item --sort=@var{key}
9755 Sort lines according to @var{key}, one of the following options:
9759 the size of each item (the default);
9761 the total size of the item's closure.
9764 @item --map-file=@var{file}
9765 Write a graphical map of disk usage in PNG format to @var{file}.
9767 For the example above, the map looks like this:
9769 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9770 produced by @command{guix size}}
9772 This option requires that
9773 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9774 installed and visible in Guile's module search path. When that is not
9775 the case, @command{guix size} fails as it tries to load it.
9777 @item --system=@var{system}
9778 @itemx -s @var{system}
9779 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9783 @node Invoking guix graph
9784 @section Invoking @command{guix graph}
9787 @cindex @command{guix graph}
9788 @cindex package dependencies
9789 Packages and their dependencies form a @dfn{graph}, specifically a
9790 directed acyclic graph (DAG). It can quickly become difficult to have a
9791 mental model of the package DAG, so the @command{guix graph} command
9792 provides a visual representation of the DAG. By default,
9793 @command{guix graph} emits a DAG representation in the input format of
9794 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9795 directly to the @command{dot} command of Graphviz. It can also emit an
9796 HTML page with embedded JavaScript code to display a ``chord diagram''
9797 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9798 emit Cypher queries to construct a graph in a graph database supporting
9799 the @uref{https://www.opencypher.org/, openCypher} query language.
9800 The general syntax is:
9803 guix graph @var{options} @var{package}@dots{}
9806 For example, the following command generates a PDF file representing the
9807 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9811 guix graph coreutils | dot -Tpdf > dag.pdf
9814 The output looks like this:
9816 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9818 Nice little graph, no?
9820 But there is more than one graph! The one above is concise: it is the
9821 graph of package objects, omitting implicit inputs such as GCC, libc,
9822 grep, etc. It is often useful to have such a concise graph, but
9823 sometimes one may want to see more details. @command{guix graph} supports
9824 several types of graphs, allowing you to choose the level of detail:
9828 This is the default type used in the example above. It shows the DAG of
9829 package objects, excluding implicit dependencies. It is concise, but
9830 filters out many details.
9832 @item reverse-package
9833 This shows the @emph{reverse} DAG of packages. For example:
9836 guix graph --type=reverse-package ocaml
9839 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9840 you are also interested in cases where OCaml is an implicit dependency, see
9841 @code{reverse-bag} below.)
9843 Note that for core packages this can yield huge graphs. If all you want
9844 is to know the number of packages that depend on a given package, use
9845 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9846 @option{--list-dependent}}).
9849 This is the package DAG, @emph{including} implicit inputs.
9851 For instance, the following command:
9854 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9857 ...@: yields this bigger graph:
9859 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9861 At the bottom of the graph, we see all the implicit inputs of
9862 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9864 Now, note that the dependencies of these implicit inputs---that is, the
9865 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9866 here, for conciseness.
9869 Similar to @code{bag-emerged}, but this time including all the bootstrap
9872 @item bag-with-origins
9873 Similar to @code{bag}, but also showing origins and their dependencies.
9876 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9877 it also takes implicit dependencies into account. For example:
9880 guix graph -t reverse-bag dune
9884 ...@: yields the graph of all packages that depend on Dune, directly or
9885 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9886 @i{via} @code{dune-build-system}, this shows a large number of packages,
9887 whereas @code{reverse-package} would show very few if any.
9890 This is the most detailed representation: It shows the DAG of
9891 derivations (@pxref{Derivations}) and plain store items. Compared to
9892 the above representation, many additional nodes are visible, including
9893 build scripts, patches, Guile modules, etc.
9895 For this type of graph, it is also possible to pass a @file{.drv} file
9896 name instead of a package name, as in:
9899 guix graph -t derivation `guix system build -d my-config.scm`
9903 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9904 For example, the following command shows the graph for the package
9905 module that defines the @code{guile} package:
9908 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9912 All the types above correspond to @emph{build-time dependencies}. The
9913 following graph type represents the @emph{run-time dependencies}:
9917 This is the graph of @dfn{references} of a package output, as returned
9918 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9920 If the given package output is not available in the store, @command{guix
9921 graph} attempts to obtain dependency information from substitutes.
9923 Here you can also pass a store file name instead of a package name. For
9924 example, the command below produces the reference graph of your profile
9925 (which can be big!):
9928 guix graph -t references `readlink -f ~/.guix-profile`
9932 This is the graph of the @dfn{referrers} of a store item, as returned by
9933 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9935 This relies exclusively on local information from your store. For
9936 instance, let us suppose that the current Inkscape is available in 10
9937 profiles on your machine; @command{guix graph -t referrers inkscape}
9938 will show a graph rooted at Inkscape and with those 10 profiles linked
9941 It can help determine what is preventing a store item from being garbage
9946 The available options are the following:
9949 @item --type=@var{type}
9950 @itemx -t @var{type}
9951 Produce a graph output of @var{type}, where @var{type} must be one of
9952 the values listed above.
9955 List the supported graph types.
9957 @item --backend=@var{backend}
9958 @itemx -b @var{backend}
9959 Produce a graph using the selected @var{backend}.
9961 @item --list-backends
9962 List the supported graph backends.
9964 Currently, the available backends are Graphviz and d3.js.
9966 @item --expression=@var{expr}
9967 @itemx -e @var{expr}
9968 Consider the package @var{expr} evaluates to.
9970 This is useful to precisely refer to a package, as in this example:
9973 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9976 @item --system=@var{system}
9977 @itemx -s @var{system}
9978 Display the graph for @var{system}---e.g., @code{i686-linux}.
9980 The package dependency graph is largely architecture-independent, but there
9981 are some architecture-dependent bits that this option allows you to visualize.
9984 On top of that, @command{guix graph} supports all the usual package
9985 transformation options (@pxref{Package Transformation Options}). This
9986 makes it easy to view the effect of a graph-rewriting transformation
9987 such as @option{--with-input}. For example, the command below outputs
9988 the graph of @code{git} once @code{openssl} has been replaced by
9989 @code{libressl} everywhere in the graph:
9992 guix graph git --with-input=openssl=libressl
9995 So many possibilities, so much fun!
9997 @node Invoking guix publish
9998 @section Invoking @command{guix publish}
10000 @cindex @command{guix publish}
10001 The purpose of @command{guix publish} is to enable users to easily share
10002 their store with others, who can then use it as a substitute server
10003 (@pxref{Substitutes}).
10005 When @command{guix publish} runs, it spawns an HTTP server which allows
10006 anyone with network access to obtain substitutes from it. This means
10007 that any machine running Guix can also act as if it were a build farm,
10008 since the HTTP interface is compatible with Cuirass, the software behind
10009 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10011 For security, each substitute is signed, allowing recipients to check
10012 their authenticity and integrity (@pxref{Substitutes}). Because
10013 @command{guix publish} uses the signing key of the system, which is only
10014 readable by the system administrator, it must be started as root; the
10015 @code{--user} option makes it drop root privileges early on.
10017 The signing key pair must be generated before @command{guix publish} is
10018 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10021 The general syntax is:
10024 guix publish @var{options}@dots{}
10027 Running @command{guix publish} without any additional arguments will
10028 spawn an HTTP server on port 8080:
10034 Once a publishing server has been authorized (@pxref{Invoking guix
10035 archive}), the daemon may download substitutes from it:
10038 guix-daemon --substitute-urls=http://example.org:8080
10041 By default, @command{guix publish} compresses archives on the fly as it
10042 serves them. This ``on-the-fly'' mode is convenient in that it requires
10043 no setup and is immediately available. However, when serving lots of
10044 clients, we recommend using the @option{--cache} option, which enables
10045 caching of the archives before they are sent to clients---see below for
10046 details. The @command{guix weather} command provides a handy way to
10047 check what a server provides (@pxref{Invoking guix weather}).
10049 As a bonus, @command{guix publish} also serves as a content-addressed
10050 mirror for source files referenced in @code{origin} records
10051 (@pxref{origin Reference}). For instance, assuming @command{guix
10052 publish} is running on @code{example.org}, the following URL returns the
10053 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10054 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10057 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10060 Obviously, these URLs only work for files that are in the store; in
10061 other cases, they return 404 (``Not Found'').
10063 @cindex build logs, publication
10064 Build logs are available from @code{/log} URLs like:
10067 http://example.org/log/gwspk@dots{}-guile-2.2.3
10071 When @command{guix-daemon} is configured to save compressed build logs,
10072 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10073 URLs return the compressed log as-is, with an appropriate
10074 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10075 running @command{guix-daemon} with @code{--log-compression=gzip} since
10076 Web browsers can automatically decompress it, which is not the case with
10079 The following options are available:
10082 @item --port=@var{port}
10083 @itemx -p @var{port}
10084 Listen for HTTP requests on @var{port}.
10086 @item --listen=@var{host}
10087 Listen on the network interface for @var{host}. The default is to
10088 accept connections from any interface.
10090 @item --user=@var{user}
10091 @itemx -u @var{user}
10092 Change privileges to @var{user} as soon as possible---i.e., once the
10093 server socket is open and the signing key has been read.
10095 @item --compression[=@var{method}[:@var{level}]]
10096 @itemx -C [@var{method}[:@var{level}]]
10097 Compress data using the given @var{method} and @var{level}. @var{method} is
10098 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10101 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10102 to different compression levels: 1 is the fastest, and 9 is the best
10103 (CPU-intensive). The default is 3.
10105 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10106 increase in CPU usage; see
10107 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10110 Unless @option{--cache} is used, compression occurs on the fly and
10111 the compressed streams are not
10112 cached. Thus, to reduce load on the machine that runs @command{guix
10113 publish}, it may be a good idea to choose a low compression level, to
10114 run @command{guix publish} behind a caching proxy, or to use
10115 @option{--cache}. Using @option{--cache} has the advantage that it
10116 allows @command{guix publish} to add @code{Content-Length} HTTP header
10119 This option can be repeated, in which case every substitute gets compressed
10120 using all the selected methods, and all of them are advertised. This is
10121 useful when users may not support all the compression methods: they can select
10122 the one they support.
10124 @item --cache=@var{directory}
10125 @itemx -c @var{directory}
10126 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10127 and only serve archives that are in cache.
10129 When this option is omitted, archives and meta-data are created
10130 on-the-fly. This can reduce the available bandwidth, especially when
10131 compression is enabled, since this may become CPU-bound. Another
10132 drawback of the default mode is that the length of archives is not known
10133 in advance, so @command{guix publish} does not add a
10134 @code{Content-Length} HTTP header to its responses, which in turn
10135 prevents clients from knowing the amount of data being downloaded.
10137 Conversely, when @option{--cache} is used, the first request for a store
10138 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10139 background process to @dfn{bake} the archive---computing its
10140 @code{.narinfo} and compressing the archive, if needed. Once the
10141 archive is cached in @var{directory}, subsequent requests succeed and
10142 are served directly from the cache, which guarantees that clients get
10143 the best possible bandwidth.
10145 The ``baking'' process is performed by worker threads. By default, one
10146 thread per CPU core is created, but this can be customized. See
10147 @option{--workers} below.
10149 When @option{--ttl} is used, cached entries are automatically deleted
10150 when they have expired.
10152 @item --workers=@var{N}
10153 When @option{--cache} is used, request the allocation of @var{N} worker
10154 threads to ``bake'' archives.
10156 @item --ttl=@var{ttl}
10157 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10158 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10159 days, @code{1m} means 1 month, and so on.
10161 This allows the user's Guix to keep substitute information in cache for
10162 @var{ttl}. However, note that @code{guix publish} does not itself
10163 guarantee that the store items it provides will indeed remain available
10164 for as long as @var{ttl}.
10166 Additionally, when @option{--cache} is used, cached entries that have
10167 not been accessed for @var{ttl} and that no longer have a corresponding
10168 item in the store, may be deleted.
10170 @item --nar-path=@var{path}
10171 Use @var{path} as the prefix for the URLs of ``nar'' files
10172 (@pxref{Invoking guix archive, normalized archives}).
10174 By default, nars are served at a URL such as
10175 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10176 change the @code{/nar} part to @var{path}.
10178 @item --public-key=@var{file}
10179 @itemx --private-key=@var{file}
10180 Use the specific @var{file}s as the public/private key pair used to sign
10181 the store items being published.
10183 The files must correspond to the same key pair (the private key is used
10184 for signing and the public key is merely advertised in the signature
10185 metadata). They must contain keys in the canonical s-expression format
10186 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10187 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10188 @file{/etc/guix/signing-key.sec} are used.
10190 @item --repl[=@var{port}]
10191 @itemx -r [@var{port}]
10192 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10193 Reference Manual}) on @var{port} (37146 by default). This is used
10194 primarily for debugging a running @command{guix publish} server.
10197 Enabling @command{guix publish} on Guix System is a one-liner: just
10198 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10199 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10200 @code{guix-publish-service-type}}).
10202 If you are instead running Guix on a ``foreign distro'', follow these
10207 If your host distro uses the systemd init system:
10210 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10211 /etc/systemd/system/
10212 # systemctl start guix-publish && systemctl enable guix-publish
10216 If your host distro uses the Upstart init system:
10219 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10220 # start guix-publish
10224 Otherwise, proceed similarly with your distro's init system.
10227 @node Invoking guix challenge
10228 @section Invoking @command{guix challenge}
10230 @cindex reproducible builds
10231 @cindex verifiable builds
10232 @cindex @command{guix challenge}
10234 Do the binaries provided by this server really correspond to the source
10235 code it claims to build? Is a package build process deterministic?
10236 These are the questions the @command{guix challenge} command attempts to
10239 The former is obviously an important question: Before using a substitute
10240 server (@pxref{Substitutes}), one had better @emph{verify} that it
10241 provides the right binaries, and thus @emph{challenge} it. The latter
10242 is what enables the former: If package builds are deterministic, then
10243 independent builds of the package should yield the exact same result,
10244 bit for bit; if a server provides a binary different from the one
10245 obtained locally, it may be either corrupt or malicious.
10247 We know that the hash that shows up in @file{/gnu/store} file names is
10248 the hash of all the inputs of the process that built the file or
10249 directory---compilers, libraries, build scripts,
10250 etc. (@pxref{Introduction}). Assuming deterministic build processes,
10251 one store file name should map to exactly one build output.
10252 @command{guix challenge} checks whether there is, indeed, a single
10253 mapping by comparing the build outputs of several independent builds of
10254 any given store item.
10256 The command output looks like this:
10259 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10260 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
10261 updating list of substitutes from 'https://guix.example.org'... 100.0%
10262 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
10263 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10264 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10265 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
10266 /gnu/store/@dots{}-git-2.5.0 contents differ:
10267 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
10268 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
10269 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
10270 /gnu/store/@dots{}-pius-2.1.1 contents differ:
10271 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10272 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10273 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
10277 6,406 store items were analyzed:
10278 - 4,749 (74.1%) were identical
10279 - 525 (8.2%) differed
10280 - 1,132 (17.7%) were inconclusive
10284 In this example, @command{guix challenge} first scans the store to
10285 determine the set of locally-built derivations---as opposed to store
10286 items that were downloaded from a substitute server---and then queries
10287 all the substitute servers. It then reports those store items for which
10288 the servers obtained a result different from the local build.
10290 @cindex non-determinism, in package builds
10291 As an example, @code{guix.example.org} always gets a different answer.
10292 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
10293 case of Git. This might indicate that the build process of Git is
10294 non-deterministic, meaning that its output varies as a function of
10295 various things that Guix does not fully control, in spite of building
10296 packages in isolated environments (@pxref{Features}). Most common
10297 sources of non-determinism include the addition of timestamps in build
10298 results, the inclusion of random numbers, and directory listings sorted
10299 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
10302 To find out what is wrong with this Git binary, we can do something along
10303 these lines (@pxref{Invoking guix archive}):
10306 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
10307 | guix archive -x /tmp/git
10308 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
10311 This command shows the difference between the files resulting from the
10312 local build, and the files resulting from the build on
10313 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
10314 diffutils, Comparing and Merging Files}). The @command{diff} command
10315 works great for text files. When binary files differ, a better option
10316 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
10317 visualize differences for all kinds of files.
10319 Once you have done that work, you can tell whether the differences are due
10320 to a non-deterministic build process or to a malicious server. We try
10321 hard to remove sources of non-determinism in packages to make it easier
10322 to verify substitutes, but of course, this is a process that
10323 involves not just Guix, but a large part of the free software community.
10324 In the meantime, @command{guix challenge} is one tool to help address
10327 If you are writing packages for Guix, you are encouraged to check
10328 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
10329 same build result as you did with:
10332 $ guix challenge @var{package}
10336 where @var{package} is a package specification such as
10337 @code{guile@@2.0} or @code{glibc:debug}.
10339 The general syntax is:
10342 guix challenge @var{options} [@var{packages}@dots{}]
10345 When a difference is found between the hash of a locally-built item and
10346 that of a server-provided substitute, or among substitutes provided by
10347 different servers, the command displays it as in the example above and
10348 its exit code is 2 (other non-zero exit codes denote other kinds of
10351 The one option that matters is:
10355 @item --substitute-urls=@var{urls}
10356 Consider @var{urls} the whitespace-separated list of substitute source
10357 URLs to compare to.
10361 Show details about matches (identical contents) in addition to
10362 information about mismatches.
10366 @node Invoking guix copy
10367 @section Invoking @command{guix copy}
10369 @cindex copy, of store items, over SSH
10370 @cindex SSH, copy of store items
10371 @cindex sharing store items across machines
10372 @cindex transferring store items across machines
10373 The @command{guix copy} command copies items from the store of one
10374 machine to that of another machine over a secure shell (SSH)
10375 connection@footnote{This command is available only when Guile-SSH was
10376 found. @xref{Requirements}, for details.}. For example, the following
10377 command copies the @code{coreutils} package, the user's profile, and all
10378 their dependencies over to @var{host}, logged in as @var{user}:
10381 guix copy --to=@var{user}@@@var{host} \
10382 coreutils `readlink -f ~/.guix-profile`
10385 If some of the items to be copied are already present on @var{host},
10386 they are not actually sent.
10388 The command below retrieves @code{libreoffice} and @code{gimp} from
10389 @var{host}, assuming they are available there:
10392 guix copy --from=@var{host} libreoffice gimp
10395 The SSH connection is established using the Guile-SSH client, which is
10396 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10397 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10399 The key used to sign items that are sent must be accepted by the remote
10400 machine. Likewise, the key used by the remote machine to sign items you
10401 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10402 own daemon. @xref{Invoking guix archive}, for more information about
10403 store item authentication.
10405 The general syntax is:
10408 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10411 You must always specify one of the following options:
10414 @item --to=@var{spec}
10415 @itemx --from=@var{spec}
10416 Specify the host to send to or receive from. @var{spec} must be an SSH
10417 spec such as @code{example.org}, @code{charlie@@example.org}, or
10418 @code{charlie@@example.org:2222}.
10421 The @var{items} can be either package names, such as @code{gimp}, or
10422 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10424 When specifying the name of a package to send, it is first built if
10425 needed, unless @option{--dry-run} was specified. Common build options
10426 are supported (@pxref{Common Build Options}).
10429 @node Invoking guix container
10430 @section Invoking @command{guix container}
10432 @cindex @command{guix container}
10434 As of version @value{VERSION}, this tool is experimental. The interface
10435 is subject to radical change in the future.
10438 The purpose of @command{guix container} is to manipulate processes
10439 running within an isolated environment, commonly known as a
10440 ``container'', typically created by the @command{guix environment}
10441 (@pxref{Invoking guix environment}) and @command{guix system container}
10442 (@pxref{Invoking guix system}) commands.
10444 The general syntax is:
10447 guix container @var{action} @var{options}@dots{}
10450 @var{action} specifies the operation to perform with a container, and
10451 @var{options} specifies the context-specific arguments for the action.
10453 The following actions are available:
10457 Execute a command within the context of a running container.
10462 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10465 @var{pid} specifies the process ID of the running container.
10466 @var{program} specifies an executable file name within the root file
10467 system of the container. @var{arguments} are the additional options that
10468 will be passed to @var{program}.
10470 The following command launches an interactive login shell inside a
10471 Guix system container, started by @command{guix system container}, and whose
10472 process ID is 9001:
10475 guix container exec 9001 /run/current-system/profile/bin/bash --login
10478 Note that the @var{pid} cannot be the parent process of a container. It
10479 must be PID 1 of the container or one of its child processes.
10483 @node Invoking guix weather
10484 @section Invoking @command{guix weather}
10486 Occasionally you're grumpy because substitutes are lacking and you end
10487 up building packages by yourself (@pxref{Substitutes}). The
10488 @command{guix weather} command reports on substitute availability on the
10489 specified servers so you can have an idea of whether you'll be grumpy
10490 today. It can sometimes be useful info as a user, but it is primarily
10491 useful to people running @command{guix publish} (@pxref{Invoking guix
10494 @cindex statistics, for substitutes
10495 @cindex availability of substitutes
10496 @cindex substitute availability
10497 @cindex weather, substitute availability
10498 Here's a sample run:
10501 $ guix weather --substitute-urls=https://guix.example.org
10502 computing 5,872 package derivations for x86_64-linux...
10503 looking for 6,128 store items on https://guix.example.org..
10504 updating list of substitutes from 'https://guix.example.org'... 100.0%
10505 https://guix.example.org
10506 43.4% substitutes available (2,658 out of 6,128)
10507 7,032.5 MiB of nars (compressed)
10508 19,824.2 MiB on disk (uncompressed)
10509 0.030 seconds per request (182.9 seconds in total)
10510 33.5 requests per second
10512 9.8% (342 out of 3,470) of the missing items are queued
10514 x86_64-linux: 518 (59.7%)
10515 i686-linux: 221 (25.5%)
10516 aarch64-linux: 128 (14.8%)
10517 build rate: 23.41 builds per hour
10518 x86_64-linux: 11.16 builds per hour
10519 i686-linux: 6.03 builds per hour
10520 aarch64-linux: 6.41 builds per hour
10523 @cindex continuous integration, statistics
10524 As you can see, it reports the fraction of all the packages for which
10525 substitutes are available on the server---regardless of whether
10526 substitutes are enabled, and regardless of whether this server's signing
10527 key is authorized. It also reports the size of the compressed archives
10528 (``nars'') provided by the server, the size the corresponding store
10529 items occupy in the store (assuming deduplication is turned off), and
10530 the server's throughput. The second part gives continuous integration
10531 (CI) statistics, if the server supports it. In addition, using the
10532 @option{--coverage} option, @command{guix weather} can list ``important''
10533 package substitutes missing on the server (see below).
10535 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10536 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10537 challenge}, it ignores signatures on those substitutes, which is
10538 innocuous since the command only gathers statistics and cannot install
10541 The general syntax is:
10544 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10547 When @var{packages} is omitted, @command{guix weather} checks the availability
10548 of substitutes for @emph{all} the packages, or for those specified with
10549 @option{--manifest}; otherwise it only considers the specified packages. It
10550 is also possible to query specific system types with @option{--system}. The
10551 available options are listed below.
10554 @item --substitute-urls=@var{urls}
10555 @var{urls} is the space-separated list of substitute server URLs to
10556 query. When this option is omitted, the default set of substitute
10557 servers is queried.
10559 @item --system=@var{system}
10560 @itemx -s @var{system}
10561 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10562 option can be repeated, in which case @command{guix weather} will query
10563 substitutes for several system types.
10565 @item --manifest=@var{file}
10566 Instead of querying substitutes for all the packages, only ask for those
10567 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10568 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10571 @item --coverage[=@var{count}]
10572 @itemx -c [@var{count}]
10573 Report on substitute coverage for packages: list packages with at least
10574 @var{count} dependents (zero by default) for which substitutes are
10575 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10576 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10577 @var{b} usually lacks substitutes as well. The result looks like this:
10580 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10581 computing 8,983 package derivations for x86_64-linux...
10582 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10583 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10584 @value{SUBSTITUTE-URL}
10585 64.7% substitutes available (6,047 out of 9,343)
10587 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10588 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10589 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10590 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10594 What this example shows is that @code{kcoreaddons} and presumably the 58
10595 packages that depend on it have no substitutes at @code{ci.guix.info};
10596 likewise for @code{qgpgme} and the 46 packages that depend on it.
10598 If you are a Guix developer, or if you are taking care of this build farm,
10599 you'll probably want to have a closer look at these packages: they may simply
10603 @node Invoking guix processes
10604 @section Invoking @command{guix processes}
10606 The @command{guix processes} command can be useful to developers and system
10607 administrators, especially on multi-user machines and on build farms: it lists
10608 the current sessions (connections to the daemon), as well as information about
10609 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10610 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10611 listed.}. Here's an example of the information it returns:
10614 $ sudo guix processes
10617 ClientCommand: guix environment --ad-hoc python
10621 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10625 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10626 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10627 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10628 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10629 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10630 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10631 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10634 In this example we see that @command{guix-daemon} has three clients:
10635 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10636 integration tool; their process identifier (PID) is given by the
10637 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10638 @command{guix-daemon} sub-process of this particular session.
10640 The @code{LockHeld} fields show which store items are currently locked by this
10641 session, which corresponds to store items being built or substituted (the
10642 @code{LockHeld} field is not displayed when @command{guix processes} is not
10643 running as root.) Last, by looking at the @code{ChildProcess} field, we
10644 understand that these three builds are being offloaded (@pxref{Daemon Offload
10647 The output is in Recutils format so we can use the handy @command{recsel}
10648 command to select sessions of interest (@pxref{Selection Expressions,,,
10649 recutils, GNU recutils manual}). As an example, the command shows the command
10650 line and PID of the client that triggered the build of a Perl package:
10653 $ sudo guix processes | \
10654 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10656 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10659 @node System Configuration
10660 @chapter System Configuration
10662 @cindex system configuration
10663 Guix System supports a consistent whole-system configuration
10664 mechanism. By that we mean that all aspects of the global system
10665 configuration---such as the available system services, timezone and
10666 locale settings, user accounts---are declared in a single place. Such
10667 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10669 One of the advantages of putting all the system configuration under the
10670 control of Guix is that it supports transactional system upgrades, and
10671 makes it possible to roll back to a previous system instantiation,
10672 should something go wrong with the new one (@pxref{Features}). Another
10673 advantage is that it makes it easy to replicate the exact same configuration
10674 across different machines, or at different points in time, without
10675 having to resort to additional administration tools layered on top of
10676 the own tools of the system.
10677 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10679 This section describes this mechanism. First we focus on the system
10680 administrator's viewpoint---explaining how the system is configured and
10681 instantiated. Then we show how this mechanism can be extended, for
10682 instance to support new system services.
10685 * Using the Configuration System:: Customizing your GNU system.
10686 * operating-system Reference:: Detail of operating-system declarations.
10687 * File Systems:: Configuring file system mounts.
10688 * Mapped Devices:: Block device extra processing.
10689 * User Accounts:: Specifying user accounts.
10690 * Keyboard Layout:: How the system interprets key strokes.
10691 * Locales:: Language and cultural convention settings.
10692 * Services:: Specifying system services.
10693 * Setuid Programs:: Programs running with root privileges.
10694 * X.509 Certificates:: Authenticating HTTPS servers.
10695 * Name Service Switch:: Configuring libc's name service switch.
10696 * Initial RAM Disk:: Linux-Libre bootstrapping.
10697 * Bootloader Configuration:: Configuring the boot loader.
10698 * Invoking guix system:: Instantiating a system configuration.
10699 * Invoking guix deploy:: Deploying a system configuration to a remote host.
10700 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10701 * Defining Services:: Adding new service definitions.
10704 @node Using the Configuration System
10705 @section Using the Configuration System
10707 The operating system is configured by providing an
10708 @code{operating-system} declaration in a file that can then be passed to
10709 the @command{guix system} command (@pxref{Invoking guix system}). A
10710 simple setup, with the default system services, the default Linux-Libre
10711 kernel, initial RAM disk, and boot loader looks like this:
10713 @findex operating-system
10715 @include os-config-bare-bones.texi
10718 This example should be self-describing. Some of the fields defined
10719 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10720 Others, such as @code{packages} and @code{services}, can be omitted, in
10721 which case they get a default value.
10723 Below we discuss the effect of some of the most important fields
10724 (@pxref{operating-system Reference}, for details about all the available
10725 fields), and how to @dfn{instantiate} the operating system using
10726 @command{guix system}.
10728 @unnumberedsubsec Bootloader
10730 @cindex legacy boot, on Intel machines
10731 @cindex BIOS boot, on Intel machines
10734 The @code{bootloader} field describes the method that will be used to boot
10735 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10736 mode, as in the example above. However, more recent machines rely instead on
10737 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10738 the @code{bootloader} field should contain something along these lines:
10741 (bootloader-configuration
10742 (bootloader grub-efi-bootloader)
10743 (target "/boot/efi"))
10746 @xref{Bootloader Configuration}, for more information on the available
10747 configuration options.
10749 @unnumberedsubsec Globally-Visible Packages
10751 @vindex %base-packages
10752 The @code{packages} field lists packages that will be globally visible
10753 on the system, for all user accounts---i.e., in every user's @code{PATH}
10754 environment variable---in addition to the per-user profiles
10755 (@pxref{Invoking guix package}). The @code{%base-packages} variable
10756 provides all the tools one would expect for basic user and administrator
10757 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10758 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10759 etc. The example above adds GNU@tie{}Screen to those,
10760 taken from the @code{(gnu packages screen)}
10761 module (@pxref{Package Modules}). The
10762 @code{(list package output)} syntax can be used to add a specific output
10766 (use-modules (gnu packages))
10767 (use-modules (gnu packages dns))
10771 (packages (cons (list bind "utils")
10775 @findex specification->package
10776 Referring to packages by variable name, like @code{bind} above, has
10777 the advantage of being unambiguous; it also allows typos and such to be
10778 diagnosed right away as ``unbound variables''. The downside is that one
10779 needs to know which module defines which package, and to augment the
10780 @code{use-package-modules} line accordingly. To avoid that, one can use
10781 the @code{specification->package} procedure of the @code{(gnu packages)}
10782 module, which returns the best package for a given name or name and
10786 (use-modules (gnu packages))
10790 (packages (append (map specification->package
10791 '("tcpdump" "htop" "gnupg@@2.0"))
10795 @unnumberedsubsec System Services
10798 @vindex %base-services
10799 The @code{services} field lists @dfn{system services} to be made
10800 available when the system starts (@pxref{Services}).
10801 The @code{operating-system} declaration above specifies that, in
10802 addition to the basic services, we want the OpenSSH secure shell
10803 daemon listening on port 2222 (@pxref{Networking Services,
10804 @code{openssh-service-type}}). Under the hood,
10805 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10806 right command-line options, possibly with supporting configuration files
10807 generated as needed (@pxref{Defining Services}).
10809 @cindex customization, of services
10810 @findex modify-services
10811 Occasionally, instead of using the base services as is, you will want to
10812 customize them. To do this, use @code{modify-services} (@pxref{Service
10813 Reference, @code{modify-services}}) to modify the list.
10815 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10816 (the console log-in) in the @code{%base-services} list (@pxref{Base
10817 Services, @code{%base-services}}). To do that, you can write the
10818 following in your operating system declaration:
10821 (define %my-services
10822 ;; My very own list of services.
10823 (modify-services %base-services
10824 (guix-service-type config =>
10825 (guix-configuration
10827 (use-substitutes? #f)
10828 (extra-options '("--gc-keep-derivations"))))
10829 (mingetty-service-type config =>
10830 (mingetty-configuration
10831 (inherit config)))))
10835 (services %my-services))
10838 This changes the configuration---i.e., the service parameters---of the
10839 @code{guix-service-type} instance, and that of all the
10840 @code{mingetty-service-type} instances in the @code{%base-services} list.
10841 Observe how this is accomplished: first, we arrange for the original
10842 configuration to be bound to the identifier @code{config} in the
10843 @var{body}, and then we write the @var{body} so that it evaluates to the
10844 desired configuration. In particular, notice how we use @code{inherit}
10845 to create a new configuration which has the same values as the old
10846 configuration, but with a few modifications.
10848 @cindex encrypted disk
10849 The configuration for a typical ``desktop'' usage, with an encrypted
10850 root partition, the X11 display
10851 server, GNOME and Xfce (users can choose which of these desktop
10852 environments to use at the log-in screen by pressing @kbd{F1}), network
10853 management, power management, and more, would look like this:
10856 @include os-config-desktop.texi
10859 A graphical system with a choice of lightweight window managers
10860 instead of full-blown desktop environments would look like this:
10863 @include os-config-lightweight-desktop.texi
10866 This example refers to the @file{/boot/efi} file system by its UUID,
10867 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10868 as returned by the @command{blkid} command.
10870 @xref{Desktop Services}, for the exact list of services provided by
10871 @code{%desktop-services}. @xref{X.509 Certificates}, for background
10872 information about the @code{nss-certs} package that is used here.
10874 Again, @code{%desktop-services} is just a list of service objects. If
10875 you want to remove services from there, you can do so using the
10876 procedures for list filtering (@pxref{SRFI-1 Filtering and
10877 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10878 following expression returns a list that contains all the services in
10879 @code{%desktop-services} minus the Avahi service:
10882 (remove (lambda (service)
10883 (eq? (service-kind service) avahi-service-type))
10887 @unnumberedsubsec Instantiating the System
10889 Assuming the @code{operating-system} declaration
10890 is stored in the @file{my-system-config.scm}
10891 file, the @command{guix system reconfigure my-system-config.scm} command
10892 instantiates that configuration, and makes it the default GRUB boot
10893 entry (@pxref{Invoking guix system}).
10895 The normal way to change the system configuration is by updating this
10896 file and re-running @command{guix system reconfigure}. One should never
10897 have to touch files in @file{/etc} or to run commands that modify the
10898 system state such as @command{useradd} or @command{grub-install}. In
10899 fact, you must avoid that since that would not only void your warranty
10900 but also prevent you from rolling back to previous versions of your
10901 system, should you ever need to.
10903 @cindex roll-back, of the operating system
10904 Speaking of roll-back, each time you run @command{guix system
10905 reconfigure}, a new @dfn{generation} of the system is created---without
10906 modifying or deleting previous generations. Old system generations get
10907 an entry in the bootloader boot menu, allowing you to boot them in case
10908 something went wrong with the latest generation. Reassuring, no? The
10909 @command{guix system list-generations} command lists the system
10910 generations available on disk. It is also possible to roll back the
10911 system via the commands @command{guix system roll-back} and
10912 @command{guix system switch-generation}.
10914 Although the @command{guix system reconfigure} command will not modify
10915 previous generations, you must take care when the current generation is not
10916 the latest (e.g., after invoking @command{guix system roll-back}), since
10917 the operation might overwrite a later generation (@pxref{Invoking guix
10920 @unnumberedsubsec The Programming Interface
10922 At the Scheme level, the bulk of an @code{operating-system} declaration
10923 is instantiated with the following monadic procedure (@pxref{The Store
10926 @deffn {Monadic Procedure} operating-system-derivation os
10927 Return a derivation that builds @var{os}, an @code{operating-system}
10928 object (@pxref{Derivations}).
10930 The output of the derivation is a single directory that refers to all
10931 the packages, configuration files, and other supporting files needed to
10932 instantiate @var{os}.
10935 This procedure is provided by the @code{(gnu system)} module. Along
10936 with @code{(gnu services)} (@pxref{Services}), this module contains the
10937 guts of Guix System. Make sure to visit it!
10940 @node operating-system Reference
10941 @section @code{operating-system} Reference
10943 This section summarizes all the options available in
10944 @code{operating-system} declarations (@pxref{Using the Configuration
10947 @deftp {Data Type} operating-system
10948 This is the data type representing an operating system configuration.
10949 By that, we mean all the global system configuration, not per-user
10950 configuration (@pxref{Using the Configuration System}).
10953 @item @code{kernel} (default: @var{linux-libre})
10954 The package object of the operating system kernel to use@footnote{Currently
10955 only the Linux-libre kernel is supported. In the future, it will be
10956 possible to use the GNU@tie{}Hurd.}.
10958 @item @code{kernel-arguments} (default: @code{'("quiet")})
10959 List of strings or gexps representing additional arguments to pass on
10960 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10962 @item @code{bootloader}
10963 The system bootloader configuration object. @xref{Bootloader Configuration}.
10966 This is the label (a string) as it appears in the bootloader's menu entry.
10967 The default label includes the kernel name and version.
10969 @item @code{keyboard-layout} (default: @code{#f})
10970 This field specifies the keyboard layout to use in the console. It can be
10971 either @code{#f}, in which case the default keyboard layout is used (usually
10972 US English), or a @code{<keyboard-layout>} record.
10974 This keyboard layout is in effect as soon as the kernel has booted. For
10975 instance, it is the keyboard layout in effect when you type a passphrase if
10976 your root file system is on a @code{luks-device-mapping} mapped device
10977 (@pxref{Mapped Devices}).
10980 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10981 that used by the graphical display server. @xref{Bootloader Configuration},
10982 for information on how to specify the bootloader's keyboard layout. @xref{X
10983 Window}, for information on how to specify the keyboard layout used by the X
10987 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10989 @cindex initial RAM disk
10990 The list of Linux kernel modules that need to be available in the
10991 initial RAM disk. @xref{Initial RAM Disk}.
10993 @item @code{initrd} (default: @code{base-initrd})
10994 A procedure that returns an initial RAM disk for the Linux
10995 kernel. This field is provided to support low-level customization and
10996 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10998 @item @code{firmware} (default: @code{%base-firmware})
11000 List of firmware packages loadable by the operating system kernel.
11002 The default includes firmware needed for Atheros- and Broadcom-based
11003 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11004 respectively). @xref{Hardware Considerations}, for more info on
11005 supported hardware.
11007 @item @code{host-name}
11010 @item @code{hosts-file}
11012 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11013 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11014 Reference Manual}). The default is a file with entries for
11015 @code{localhost} and @var{host-name}.
11017 @item @code{mapped-devices} (default: @code{'()})
11018 A list of mapped devices. @xref{Mapped Devices}.
11020 @item @code{file-systems}
11021 A list of file systems. @xref{File Systems}.
11023 @item @code{swap-devices} (default: @code{'()})
11024 @cindex swap devices
11025 A list of strings identifying devices or files to be used for ``swap
11026 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11027 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11028 It is possible to specify a swap file in a file system on a mapped
11029 device, provided that the necessary device mapping and file system are
11030 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11032 @item @code{users} (default: @code{%base-user-accounts})
11033 @itemx @code{groups} (default: @code{%base-groups})
11034 List of user accounts and groups. @xref{User Accounts}.
11036 If the @code{users} list lacks a user account with UID@tie{}0, a
11037 ``root'' account with UID@tie{}0 is automatically added.
11039 @item @code{skeletons} (default: @code{(default-skeletons)})
11040 A list target file name/file-like object tuples (@pxref{G-Expressions,
11041 file-like objects}). These are the skeleton files that will be added to
11042 the home directory of newly-created user accounts.
11044 For instance, a valid value may look like this:
11047 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11048 (".guile" ,(plain-file "guile"
11049 "(use-modules (ice-9 readline))
11050 (activate-readline)")))
11053 @item @code{issue} (default: @code{%default-issue})
11054 A string denoting the contents of the @file{/etc/issue} file, which is
11055 displayed when users log in on a text console.
11057 @item @code{packages} (default: @code{%base-packages})
11058 The set of packages installed in the global profile, which is accessible
11059 at @file{/run/current-system/profile}.
11061 The default set includes core utilities and it is good practice to
11062 install non-core utilities in user profiles (@pxref{Invoking guix
11065 @item @code{timezone}
11066 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11068 You can run the @command{tzselect} command to find out which timezone
11069 string corresponds to your region. Choosing an invalid timezone name
11070 causes @command{guix system} to fail.
11072 @item @code{locale} (default: @code{"en_US.utf8"})
11073 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11074 Library Reference Manual}). @xref{Locales}, for more information.
11076 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11077 The list of locale definitions to be compiled and that may be used at
11078 run time. @xref{Locales}.
11080 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11081 The list of GNU@tie{}libc packages whose locale data and tools are used
11082 to build the locale definitions. @xref{Locales}, for compatibility
11083 considerations that justify this option.
11085 @item @code{name-service-switch} (default: @code{%default-nss})
11086 Configuration of the libc name service switch (NSS)---a
11087 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11090 @item @code{services} (default: @code{%base-services})
11091 A list of service objects denoting system services. @xref{Services}.
11093 @cindex essential services
11094 @item @code{essential-services} (default: ...)
11095 The list of ``essential services''---i.e., things like instances of
11096 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11097 Reference}), which are derived from the operating system definition itself.
11098 As a user you should @emph{never} need to touch this field.
11100 @item @code{pam-services} (default: @code{(base-pam-services)})
11102 @cindex pluggable authentication modules
11103 Linux @dfn{pluggable authentication module} (PAM) services.
11104 @c FIXME: Add xref to PAM services section.
11106 @item @code{setuid-programs} (default: @var{%setuid-programs})
11107 List of string-valued G-expressions denoting setuid programs.
11108 @xref{Setuid Programs}.
11110 @item @code{sudoers-file} (default: @var{%sudoers-specification})
11111 @cindex sudoers file
11112 The contents of the @file{/etc/sudoers} file as a file-like object
11113 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11115 This file specifies which users can use the @command{sudo} command, what
11116 they are allowed to do, and what privileges they may gain. The default
11117 is that only @code{root} and members of the @code{wheel} group may use
11122 @deffn {Scheme Syntax} this-operating-system
11123 When used in the @emph{lexical scope} of an operating system field definition,
11124 this identifier resolves to the operating system being defined.
11126 The example below shows how to refer to the operating system being defined in
11127 the definition of the @code{label} field:
11130 (use-modules (gnu) (guix))
11134 (label (package-full-name
11135 (operating-system-kernel this-operating-system))))
11138 It is an error to refer to @code{this-operating-system} outside an operating
11145 @section File Systems
11147 The list of file systems to be mounted is specified in the
11148 @code{file-systems} field of the operating system declaration
11149 (@pxref{Using the Configuration System}). Each file system is declared
11150 using the @code{file-system} form, like this:
11154 (mount-point "/home")
11155 (device "/dev/sda3")
11159 As usual, some of the fields are mandatory---those shown in the example
11160 above---while others can be omitted. These are described below.
11162 @deftp {Data Type} file-system
11163 Objects of this type represent file systems to be mounted. They
11164 contain the following members:
11168 This is a string specifying the type of the file system---e.g.,
11171 @item @code{mount-point}
11172 This designates the place where the file system is to be mounted.
11174 @item @code{device}
11175 This names the ``source'' of the file system. It can be one of three
11176 things: a file system label, a file system UUID, or the name of a
11177 @file{/dev} node. Labels and UUIDs offer a way to refer to file
11178 systems without having to hard-code their actual device
11179 name@footnote{Note that, while it is tempting to use
11180 @file{/dev/disk/by-uuid} and similar device names to achieve the same
11181 result, this is not recommended: These special device nodes are created
11182 by the udev daemon and may be unavailable at the time the device is
11185 @findex file-system-label
11186 File system labels are created using the @code{file-system-label}
11187 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
11188 plain strings. Here's an example of a file system referred to by its
11189 label, as shown by the @command{e2label} command:
11193 (mount-point "/home")
11195 (device (file-system-label "my-home")))
11199 UUIDs are converted from their string representation (as shown by the
11200 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
11201 @code{uuid} form expects 16-byte UUIDs as defined in
11202 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
11203 form of UUID used by the ext2 family of file systems and others, but it
11204 is different from ``UUIDs'' found in FAT file systems, for instance.},
11209 (mount-point "/home")
11211 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
11214 When the source of a file system is a mapped device (@pxref{Mapped
11215 Devices}), its @code{device} field @emph{must} refer to the mapped
11216 device name---e.g., @file{"/dev/mapper/root-partition"}.
11217 This is required so that
11218 the system knows that mounting the file system depends on having the
11219 corresponding device mapping established.
11221 @item @code{flags} (default: @code{'()})
11222 This is a list of symbols denoting mount flags. Recognized flags
11223 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
11224 access to special files), @code{no-suid} (ignore setuid and setgid
11225 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
11226 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
11227 Library Reference Manual}, for more information on these flags.
11229 @item @code{options} (default: @code{#f})
11230 This is either @code{#f}, or a string denoting mount options passed to the
11231 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
11232 Reference Manual}, for details and run @command{man 8 mount} for options for
11233 various file systems.
11235 @item @code{mount?} (default: @code{#t})
11236 This value indicates whether to automatically mount the file system when
11237 the system is brought up. When set to @code{#f}, the file system gets
11238 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
11239 is not automatically mounted.
11241 @item @code{needed-for-boot?} (default: @code{#f})
11242 This Boolean value indicates whether the file system is needed when
11243 booting. If that is true, then the file system is mounted when the
11244 initial RAM disk (initrd) is loaded. This is always the case, for
11245 instance, for the root file system.
11247 @item @code{check?} (default: @code{#t})
11248 This Boolean indicates whether the file system needs to be checked for
11249 errors before being mounted.
11251 @item @code{create-mount-point?} (default: @code{#f})
11252 When true, the mount point is created if it does not exist yet.
11254 @item @code{dependencies} (default: @code{'()})
11255 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
11256 representing file systems that must be mounted or mapped devices that
11257 must be opened before (and unmounted or closed after) this one.
11259 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
11260 a dependency of @file{/sys/fs/cgroup/cpu} and
11261 @file{/sys/fs/cgroup/memory}.
11263 Another example is a file system that depends on a mapped device, for
11264 example for an encrypted partition (@pxref{Mapped Devices}).
11268 The @code{(gnu system file-systems)} exports the following useful
11271 @defvr {Scheme Variable} %base-file-systems
11272 These are essential file systems that are required on normal systems,
11273 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
11274 below.) Operating system declarations should always contain at least
11278 @defvr {Scheme Variable} %pseudo-terminal-file-system
11279 This is the file system to be mounted as @file{/dev/pts}. It supports
11280 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
11281 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
11282 Manual}). Pseudo-terminals are used by terminal emulators such as
11286 @defvr {Scheme Variable} %shared-memory-file-system
11287 This file system is mounted as @file{/dev/shm} and is used to support
11288 memory sharing across processes (@pxref{Memory-mapped I/O,
11289 @code{shm_open},, libc, The GNU C Library Reference Manual}).
11292 @defvr {Scheme Variable} %immutable-store
11293 This file system performs a read-only ``bind mount'' of
11294 @file{/gnu/store}, making it read-only for all the users including
11295 @code{root}. This prevents against accidental modification by software
11296 running as @code{root} or by system administrators.
11298 The daemon itself is still able to write to the store: it remounts it
11299 read-write in its own ``name space.''
11302 @defvr {Scheme Variable} %binary-format-file-system
11303 The @code{binfmt_misc} file system, which allows handling of arbitrary
11304 executable file types to be delegated to user space. This requires the
11305 @code{binfmt.ko} kernel module to be loaded.
11308 @defvr {Scheme Variable} %fuse-control-file-system
11309 The @code{fusectl} file system, which allows unprivileged users to mount
11310 and unmount user-space FUSE file systems. This requires the
11311 @code{fuse.ko} kernel module to be loaded.
11314 @node Mapped Devices
11315 @section Mapped Devices
11317 @cindex device mapping
11318 @cindex mapped devices
11319 The Linux kernel has a notion of @dfn{device mapping}: a block device,
11320 such as a hard disk partition, can be @dfn{mapped} into another device,
11321 usually in @code{/dev/mapper/},
11322 with additional processing over the data that flows through
11323 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
11324 concept of a ``mapped device'' and that of a file system: both boil down
11325 to @emph{translating} input/output operations made on a file to
11326 operations on its backing store. Thus, the Hurd implements mapped
11327 devices, like file systems, using the generic @dfn{translator} mechanism
11328 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
11329 typical example is encryption device mapping: all writes to the mapped
11330 device are encrypted, and all reads are deciphered, transparently.
11331 Guix extends this notion by considering any device or set of devices that
11332 are @dfn{transformed} in some way to create a new device; for instance,
11333 RAID devices are obtained by @dfn{assembling} several other devices, such
11334 as hard disks or partitions, into a new one that behaves as one partition.
11335 Other examples, not yet implemented, are LVM logical volumes.
11337 Mapped devices are declared using the @code{mapped-device} form,
11338 defined as follows; for examples, see below.
11340 @deftp {Data Type} mapped-device
11341 Objects of this type represent device mappings that will be made when
11342 the system boots up.
11346 This is either a string specifying the name of the block device to be mapped,
11347 such as @code{"/dev/sda3"}, or a list of such strings when several devices
11348 need to be assembled for creating a new one.
11351 This string specifies the name of the resulting mapped device. For
11352 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11353 specifying @code{"my-partition"} leads to the creation of
11354 the @code{"/dev/mapper/my-partition"} device.
11355 For RAID devices of type @code{raid-device-mapping}, the full device name
11356 such as @code{"/dev/md0"} needs to be given.
11359 This must be a @code{mapped-device-kind} object, which specifies how
11360 @var{source} is mapped to @var{target}.
11364 @defvr {Scheme Variable} luks-device-mapping
11365 This defines LUKS block device encryption using the @command{cryptsetup}
11366 command from the package with the same name. It relies on the
11367 @code{dm-crypt} Linux kernel module.
11370 @defvr {Scheme Variable} raid-device-mapping
11371 This defines a RAID device, which is assembled using the @code{mdadm}
11372 command from the package with the same name. It requires a Linux kernel
11373 module for the appropriate RAID level to be loaded, such as @code{raid456}
11374 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11377 @cindex disk encryption
11379 The following example specifies a mapping from @file{/dev/sda3} to
11380 @file{/dev/mapper/home} using LUKS---the
11381 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11382 standard mechanism for disk encryption.
11383 The @file{/dev/mapper/home}
11384 device can then be used as the @code{device} of a @code{file-system}
11385 declaration (@pxref{File Systems}).
11389 (source "/dev/sda3")
11391 (type luks-device-mapping))
11394 Alternatively, to become independent of device numbering, one may obtain
11395 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11399 cryptsetup luksUUID /dev/sda3
11402 and use it as follows:
11406 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11408 (type luks-device-mapping))
11411 @cindex swap encryption
11412 It is also desirable to encrypt swap space, since swap space may contain
11413 sensitive data. One way to accomplish that is to use a swap file in a
11414 file system on a device mapped via LUKS encryption. In this way, the
11415 swap file is encrypted because the entire device is encrypted.
11416 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11418 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11419 may be declared as follows:
11423 (source (list "/dev/sda1" "/dev/sdb1"))
11424 (target "/dev/md0")
11425 (type raid-device-mapping))
11428 The @file{/dev/md0} device can then be used as the @code{device} of a
11429 @code{file-system} declaration (@pxref{File Systems}).
11430 Note that the RAID level need not be given; it is chosen during the
11431 initial creation and formatting of the RAID device and is determined
11432 automatically later.
11435 @node User Accounts
11436 @section User Accounts
11440 @cindex user accounts
11441 User accounts and groups are entirely managed through the
11442 @code{operating-system} declaration. They are specified with the
11443 @code{user-account} and @code{user-group} forms:
11449 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11450 "audio" ;sound card
11451 "video" ;video devices such as webcams
11452 "cdrom")) ;the good ol' CD-ROM
11453 (comment "Bob's sister")
11454 (home-directory "/home/alice"))
11457 When booting or upon completion of @command{guix system reconfigure},
11458 the system ensures that only the user accounts and groups specified in
11459 the @code{operating-system} declaration exist, and with the specified
11460 properties. Thus, account or group creations or modifications made by
11461 directly invoking commands such as @command{useradd} are lost upon
11462 reconfiguration or reboot. This ensures that the system remains exactly
11465 @deftp {Data Type} user-account
11466 Objects of this type represent user accounts. The following members may
11471 The name of the user account.
11475 This is the name (a string) or identifier (a number) of the user group
11476 this account belongs to.
11478 @item @code{supplementary-groups} (default: @code{'()})
11479 Optionally, this can be defined as a list of group names that this
11480 account belongs to.
11482 @item @code{uid} (default: @code{#f})
11483 This is the user ID for this account (a number), or @code{#f}. In the
11484 latter case, a number is automatically chosen by the system when the
11485 account is created.
11487 @item @code{comment} (default: @code{""})
11488 A comment about the account, such as the account owner's full name.
11490 @item @code{home-directory}
11491 This is the name of the home directory for the account.
11493 @item @code{create-home-directory?} (default: @code{#t})
11494 Indicates whether the home directory of this account should be created
11495 if it does not exist yet.
11497 @item @code{shell} (default: Bash)
11498 This is a G-expression denoting the file name of a program to be used as
11499 the shell (@pxref{G-Expressions}).
11501 @item @code{system?} (default: @code{#f})
11502 This Boolean value indicates whether the account is a ``system''
11503 account. System accounts are sometimes treated specially; for instance,
11504 graphical login managers do not list them.
11506 @anchor{user-account-password}
11507 @cindex password, for user accounts
11508 @item @code{password} (default: @code{#f})
11509 You would normally leave this field to @code{#f}, initialize user
11510 passwords as @code{root} with the @command{passwd} command, and then let
11511 users change it with @command{passwd}. Passwords set with
11512 @command{passwd} are of course preserved across reboot and
11515 If you @emph{do} want to set an initial password for an account, then
11516 this field must contain the encrypted password, as a string. You can use the
11517 @code{crypt} procedure for this purpose:
11524 ;; Specify a SHA-512-hashed initial password.
11525 (password (crypt "InitialPassword!" "$6$abc")))
11529 The hash of this initial password will be available in a file in
11530 @file{/gnu/store}, readable by all the users, so this method must be used with
11534 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11535 more information on password encryption, and @ref{Encryption,,, guile, GNU
11536 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11542 User group declarations are even simpler:
11545 (user-group (name "students"))
11548 @deftp {Data Type} user-group
11549 This type is for, well, user groups. There are just a few fields:
11553 The name of the group.
11555 @item @code{id} (default: @code{#f})
11556 The group identifier (a number). If @code{#f}, a new number is
11557 automatically allocated when the group is created.
11559 @item @code{system?} (default: @code{#f})
11560 This Boolean value indicates whether the group is a ``system'' group.
11561 System groups have low numerical IDs.
11563 @item @code{password} (default: @code{#f})
11564 What, user groups can have a password? Well, apparently yes. Unless
11565 @code{#f}, this field specifies the password of the group.
11570 For convenience, a variable lists all the basic user groups one may
11573 @defvr {Scheme Variable} %base-groups
11574 This is the list of basic user groups that users and/or packages expect
11575 to be present on the system. This includes groups such as ``root'',
11576 ``wheel'', and ``users'', as well as groups used to control access to
11577 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11580 @defvr {Scheme Variable} %base-user-accounts
11581 This is the list of basic system accounts that programs may expect to
11582 find on a GNU/Linux system, such as the ``nobody'' account.
11584 Note that the ``root'' account is not included here. It is a
11585 special-case and is automatically added whether or not it is specified.
11588 @node Keyboard Layout
11589 @section Keyboard Layout
11591 @cindex keyboard layout
11593 To specify what each key of your keyboard does, you need to tell the operating
11594 system what @dfn{keyboard layout} you want to use. The default, when nothing
11595 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11596 However, German speakers will usually prefer the German QWERTZ layout, French
11597 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11598 or bépo, and they might even want to further customize the effect of some of
11599 the keys. This section explains how to get that done.
11601 @cindex keyboard layout, definition
11602 There are three components that will want to know about your keyboard layout:
11606 The @emph{bootloader} may want to know what keyboard layout you want to use
11607 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11608 you want, for instance, to make sure that you can type the passphrase of your
11609 encrypted root partition using the right layout.
11612 The @emph{operating system kernel}, Linux, will need that so that the console
11613 is properly configured (@pxref{operating-system Reference,
11614 @code{keyboard-layout}}).
11617 The @emph{graphical display server}, usually Xorg, also has its own idea of
11618 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11621 Guix allows you to configure all three separately but, fortunately, it allows
11622 you to share the same keyboard layout for all three components.
11624 @cindex XKB, keyboard layouts
11625 Keyboard layouts are represented by records created by the
11626 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11627 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11628 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11629 optional variant name, an optional keyboard model name, and a possibly empty
11630 list of additional options. In most cases the layout name is all you care
11631 about. Here are a few example:
11634 ;; The German QWERTZ layout. Here we assume a standard
11635 ;; "pc105" keyboard model.
11636 (keyboard-layout "de")
11638 ;; The bépo variant of the French layout.
11639 (keyboard-layout "fr" "bepo")
11641 ;; The Catalan layout.
11642 (keyboard-layout "es" "cat")
11644 ;; The Latin American Spanish layout. In addition, the
11645 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11646 ;; and the "Menu" key is used as a "Compose" key to enter
11647 ;; accented letters.
11648 (keyboard-layout "latam"
11649 #:options '("ctrl:nocaps" "compose:menu"))
11651 ;; The Russian layout for a ThinkPad keyboard.
11652 (keyboard-layout "ru" #:model "thinkpad")
11654 ;; The "US international" layout, which is the US layout plus
11655 ;; dead keys to enter accented characters. This is for an
11656 ;; Apple MacBook keyboard.
11657 (keyboard-layout "us" "intl" #:model "macbook78")
11660 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11661 for a complete list of supported layouts, variants, and models.
11663 @cindex keyboard layout, configuration
11664 Let's say you want your system to use the Turkish keyboard layout throughout
11665 your system---bootloader, console, and Xorg. Here's what your system
11666 configuration would look like:
11668 @findex set-xorg-configuration
11670 ;; Using the Turkish layout for the bootloader, the console,
11675 (keyboard-layout (keyboard-layout "tr")) ;for the console
11676 (bootloader (bootloader-configuration
11677 (bootloader grub-efi-bootloader)
11678 (target "/boot/efi")
11679 (keyboard-layout keyboard-layout))) ;for GRUB
11680 (services (cons (set-xorg-configuration
11681 (xorg-configuration ;for Xorg
11682 (keyboard-layout keyboard-layout)))
11683 %desktop-services)))
11686 In the example above, for GRUB and for Xorg, we just refer to the
11687 @code{keyboard-layout} field defined above, but we could just as well refer to
11688 a different layout. The @code{set-xorg-configuration} procedure communicates
11689 the desired Xorg configuration to the graphical log-in manager, by default
11692 We've discussed how to specify the @emph{default} keyboard layout of your
11693 system when it starts, but you can also adjust it at run time:
11697 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11698 where you can select one or more keyboard layouts.
11701 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11702 allows you to change the current layout. For example, this is how you would
11703 change the layout to US Dvorak:
11706 setxkbmap us dvorak
11710 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11711 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11712 keyboard layout categorization described above. The command below loads the
11713 French bépo layout:
11724 A @dfn{locale} defines cultural conventions for a particular language
11725 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11726 Reference Manual}). Each locale has a name that typically has the form
11727 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11728 @code{fr_LU.utf8} designates the locale for the French language, with
11729 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11731 @cindex locale definition
11732 Usually, you will want to specify the default locale for the machine
11733 using the @code{locale} field of the @code{operating-system} declaration
11734 (@pxref{operating-system Reference, @code{locale}}).
11736 The selected locale is automatically added to the @dfn{locale
11737 definitions} known to the system if needed, with its codeset inferred
11738 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11739 @code{UTF-8} codeset. Additional locale definitions can be specified in
11740 the @code{locale-definitions} slot of @code{operating-system}---this is
11741 useful, for instance, if the codeset could not be inferred from the
11742 locale name. The default set of locale definitions includes some widely
11743 used locales, but not all the available locales, in order to save space.
11745 For instance, to add the North Frisian locale for Germany, the value of
11749 (cons (locale-definition
11750 (name "fy_DE.utf8") (source "fy_DE"))
11751 %default-locale-definitions)
11754 Likewise, to save space, one might want @code{locale-definitions} to
11755 list only the locales that are actually used, as in:
11758 (list (locale-definition
11759 (name "ja_JP.eucjp") (source "ja_JP")
11760 (charset "EUC-JP")))
11764 The compiled locale definitions are available at
11765 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11766 version, which is the default location where the GNU@tie{}libc provided
11767 by Guix looks for locale data. This can be overridden using the
11768 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11769 @code{LOCPATH} and locale packages}).
11771 The @code{locale-definition} form is provided by the @code{(gnu system
11772 locale)} module. Details are given below.
11774 @deftp {Data Type} locale-definition
11775 This is the data type of a locale definition.
11780 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11781 Reference Manual}, for more information on locale names.
11783 @item @code{source}
11784 The name of the source for that locale. This is typically the
11785 @code{@var{language}_@var{territory}} part of the locale name.
11787 @item @code{charset} (default: @code{"UTF-8"})
11788 The ``character set'' or ``code set'' for that locale,
11789 @uref{https://www.iana.org/assignments/character-sets, as defined by
11795 @defvr {Scheme Variable} %default-locale-definitions
11796 A list of commonly used UTF-8 locales, used as the default
11797 value of the @code{locale-definitions} field of @code{operating-system}
11800 @cindex locale name
11801 @cindex normalized codeset in locale names
11802 These locale definitions use the @dfn{normalized codeset} for the part
11803 that follows the dot in the name (@pxref{Using gettextized software,
11804 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11805 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11806 @code{uk_UA.UTF-8}.
11809 @subsection Locale Data Compatibility Considerations
11811 @cindex incompatibility, of locale data
11812 @code{operating-system} declarations provide a @code{locale-libcs} field
11813 to specify the GNU@tie{}libc packages that are used to compile locale
11814 declarations (@pxref{operating-system Reference}). ``Why would I
11815 care?'', you may ask. Well, it turns out that the binary format of
11816 locale data is occasionally incompatible from one libc version to
11819 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11820 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11821 For instance, a program linked against libc version 2.21 is unable to
11822 read locale data produced with libc 2.22; worse, that program
11823 @emph{aborts} instead of simply ignoring the incompatible locale
11824 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11825 the incompatible locale data, which is already an improvement.}.
11826 Similarly, a program linked against libc 2.22 can read most, but not
11827 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11828 data is incompatible); thus calls to @code{setlocale} may fail, but
11829 programs will not abort.
11831 The ``problem'' with Guix is that users have a lot of freedom: They can
11832 choose whether and when to upgrade software in their profiles, and might
11833 be using a libc version different from the one the system administrator
11834 used to build the system-wide locale data.
11836 Fortunately, unprivileged users can also install their own locale data
11837 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11838 @code{GUIX_LOCPATH} and locale packages}).
11840 Still, it is best if the system-wide locale data at
11841 @file{/run/current-system/locale} is built for all the libc versions
11842 actually in use on the system, so that all the programs can access
11843 it---this is especially crucial on a multi-user system. To do that, the
11844 administrator can specify several libc packages in the
11845 @code{locale-libcs} field of @code{operating-system}:
11848 (use-package-modules base)
11852 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11855 This example would lead to a system containing locale definitions for
11856 both libc 2.21 and the current version of libc in
11857 @file{/run/current-system/locale}.
11863 @cindex system services
11864 An important part of preparing an @code{operating-system} declaration is
11865 listing @dfn{system services} and their configuration (@pxref{Using the
11866 Configuration System}). System services are typically daemons launched
11867 when the system boots, or other actions needed at that time---e.g.,
11868 configuring network access.
11870 Guix has a broad definition of ``service'' (@pxref{Service
11871 Composition}), but many services are managed by the GNU@tie{}Shepherd
11872 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11873 command allows you to list the available services, show their status,
11874 start and stop them, or do other specific operations (@pxref{Jump
11875 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11881 The above command, run as @code{root}, lists the currently defined
11882 services. The @command{herd doc} command shows a synopsis of the given
11883 service and its associated actions:
11887 Run libc's name service cache daemon (nscd).
11889 # herd doc nscd action invalidate
11890 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11893 The @command{start}, @command{stop}, and @command{restart} sub-commands
11894 have the effect you would expect. For instance, the commands below stop
11895 the nscd service and restart the Xorg display server:
11899 Service nscd has been stopped.
11900 # herd restart xorg-server
11901 Service xorg-server has been stopped.
11902 Service xorg-server has been started.
11905 The following sections document the available services, starting with
11906 the core services, that may be used in an @code{operating-system}
11910 * Base Services:: Essential system services.
11911 * Scheduled Job Execution:: The mcron service.
11912 * Log Rotation:: The rottlog service.
11913 * Networking Services:: Network setup, SSH daemon, etc.
11914 * X Window:: Graphical display.
11915 * Printing Services:: Local and remote printer support.
11916 * Desktop Services:: D-Bus and desktop services.
11917 * Sound Services:: ALSA and Pulseaudio services.
11918 * Database Services:: SQL databases, key-value stores, etc.
11919 * Mail Services:: IMAP, POP3, SMTP, and all that.
11920 * Messaging Services:: Messaging services.
11921 * Telephony Services:: Telephony services.
11922 * Monitoring Services:: Monitoring services.
11923 * Kerberos Services:: Kerberos services.
11924 * LDAP Services:: LDAP services.
11925 * Web Services:: Web servers.
11926 * Certificate Services:: TLS certificates via Let's Encrypt.
11927 * DNS Services:: DNS daemons.
11928 * VPN Services:: VPN daemons.
11929 * Network File System:: NFS related services.
11930 * Continuous Integration:: The Cuirass service.
11931 * Power Management Services:: Extending battery life.
11932 * Audio Services:: The MPD.
11933 * Virtualization Services:: Virtualization services.
11934 * Version Control Services:: Providing remote access to Git repositories.
11935 * Game Services:: Game servers.
11936 * PAM Mount Service:: Service to mount volumes when logging in.
11937 * Guix Services:: Services relating specifically to Guix.
11938 * Miscellaneous Services:: Other services.
11941 @node Base Services
11942 @subsection Base Services
11944 The @code{(gnu services base)} module provides definitions for the basic
11945 services that one expects from the system. The services exported by
11946 this module are listed below.
11948 @defvr {Scheme Variable} %base-services
11949 This variable contains a list of basic services (@pxref{Service Types
11950 and Services}, for more information on service objects) one would
11951 expect from the system: a login service (mingetty) on each tty, syslogd,
11952 the libc name service cache daemon (nscd), the udev device manager, and
11955 This is the default value of the @code{services} field of
11956 @code{operating-system} declarations. Usually, when customizing a
11957 system, you will want to append services to @code{%base-services}, like
11961 (append (list (service avahi-service-type)
11962 (service openssh-service-type))
11967 @defvr {Scheme Variable} special-files-service-type
11968 This is the service that sets up ``special files'' such as
11969 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11971 The value associated with @code{special-files-service-type} services
11972 must be a list of tuples where the first element is the ``special file''
11973 and the second element is its target. By default it is:
11975 @cindex @file{/bin/sh}
11976 @cindex @file{sh}, in @file{/bin}
11978 `(("/bin/sh" ,(file-append bash "/bin/sh")))
11981 @cindex @file{/usr/bin/env}
11982 @cindex @file{env}, in @file{/usr/bin}
11983 If you want to add, say, @code{/usr/bin/env} to your system, you can
11987 `(("/bin/sh" ,(file-append bash "/bin/sh"))
11988 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
11991 Since this is part of @code{%base-services}, you can use
11992 @code{modify-services} to customize the set of special files
11993 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11994 to add a special file is @i{via} the @code{extra-special-file} procedure
11998 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11999 Use @var{target} as the ``special file'' @var{file}.
12001 For example, adding the following lines to the @code{services} field of
12002 your operating system declaration leads to a @file{/usr/bin/env}
12006 (extra-special-file "/usr/bin/env"
12007 (file-append coreutils "/bin/env"))
12011 @deffn {Scheme Procedure} host-name-service @var{name}
12012 Return a service that sets the host name to @var{name}.
12015 @deffn {Scheme Procedure} login-service @var{config}
12016 Return a service to run login according to @var{config}, a
12017 @code{<login-configuration>} object, which specifies the message of the day,
12018 among other things.
12021 @deftp {Data Type} login-configuration
12022 This is the data type representing the configuration of login.
12027 @cindex message of the day
12028 A file-like object containing the ``message of the day''.
12030 @item @code{allow-empty-passwords?} (default: @code{#t})
12031 Allow empty passwords by default so that first-time users can log in when
12032 the 'root' account has just been created.
12037 @deffn {Scheme Procedure} mingetty-service @var{config}
12038 Return a service to run mingetty according to @var{config}, a
12039 @code{<mingetty-configuration>} object, which specifies the tty to run, among
12043 @deftp {Data Type} mingetty-configuration
12044 This is the data type representing the configuration of Mingetty, which
12045 provides the default implementation of virtual console log-in.
12050 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
12052 @item @code{auto-login} (default: @code{#f})
12053 When true, this field must be a string denoting the user name under
12054 which the system automatically logs in. When it is @code{#f}, a
12055 user name and password must be entered to log in.
12057 @item @code{login-program} (default: @code{#f})
12058 This must be either @code{#f}, in which case the default log-in program
12059 is used (@command{login} from the Shadow tool suite), or a gexp denoting
12060 the name of the log-in program.
12062 @item @code{login-pause?} (default: @code{#f})
12063 When set to @code{#t} in conjunction with @var{auto-login}, the user
12064 will have to press a key before the log-in shell is launched.
12066 @item @code{mingetty} (default: @var{mingetty})
12067 The Mingetty package to use.
12072 @deffn {Scheme Procedure} agetty-service @var{config}
12073 Return a service to run agetty according to @var{config}, an
12074 @code{<agetty-configuration>} object, which specifies the tty to run,
12075 among other things.
12078 @deftp {Data Type} agetty-configuration
12079 This is the data type representing the configuration of agetty, which
12080 implements virtual and serial console log-in. See the @code{agetty(8)}
12081 man page for more information.
12086 The name of the console this agetty runs on, as a string---e.g.,
12087 @code{"ttyS0"}. This argument is optional, it will default to
12088 a reasonable default serial port used by the kernel Linux.
12090 For this, if there is a value for an option @code{agetty.tty} in the kernel
12091 command line, agetty will extract the device name of the serial port
12092 from it and use that.
12094 If not and if there is a value for an option @code{console} with a tty in
12095 the Linux command line, agetty will extract the device name of the
12096 serial port from it and use that.
12098 In both cases, agetty will leave the other serial device settings
12099 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
12102 @item @code{baud-rate} (default: @code{#f})
12103 A string containing a comma-separated list of one or more baud rates, in
12106 @item @code{term} (default: @code{#f})
12107 A string containing the value used for the @code{TERM} environment
12110 @item @code{eight-bits?} (default: @code{#f})
12111 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
12114 @item @code{auto-login} (default: @code{#f})
12115 When passed a login name, as a string, the specified user will be logged
12116 in automatically without prompting for their login name or password.
12118 @item @code{no-reset?} (default: @code{#f})
12119 When @code{#t}, don't reset terminal cflags (control modes).
12121 @item @code{host} (default: @code{#f})
12122 This accepts a string containing the "login_host", which will be written
12123 into the @file{/var/run/utmpx} file.
12125 @item @code{remote?} (default: @code{#f})
12126 When set to @code{#t} in conjunction with @var{host}, this will add an
12127 @code{-r} fakehost option to the command line of the login program
12128 specified in @var{login-program}.
12130 @item @code{flow-control?} (default: @code{#f})
12131 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
12133 @item @code{no-issue?} (default: @code{#f})
12134 When set to @code{#t}, the contents of the @file{/etc/issue} file will
12135 not be displayed before presenting the login prompt.
12137 @item @code{init-string} (default: @code{#f})
12138 This accepts a string that will be sent to the tty or modem before
12139 sending anything else. It can be used to initialize a modem.
12141 @item @code{no-clear?} (default: @code{#f})
12142 When set to @code{#t}, agetty will not clear the screen before showing
12145 @item @code{login-program} (default: (file-append shadow "/bin/login"))
12146 This must be either a gexp denoting the name of a log-in program, or
12147 unset, in which case the default value is the @command{login} from the
12150 @item @code{local-line} (default: @code{#f})
12151 Control the CLOCAL line flag. This accepts one of three symbols as
12152 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
12153 the default value chosen by agetty is @code{'auto}.
12155 @item @code{extract-baud?} (default: @code{#f})
12156 When set to @code{#t}, instruct agetty to try to extract the baud rate
12157 from the status messages produced by certain types of modems.
12159 @item @code{skip-login?} (default: @code{#f})
12160 When set to @code{#t}, do not prompt the user for a login name. This
12161 can be used with @var{login-program} field to use non-standard login
12164 @item @code{no-newline?} (default: @code{#f})
12165 When set to @code{#t}, do not print a newline before printing the
12166 @file{/etc/issue} file.
12168 @c Is this dangerous only when used with login-program, or always?
12169 @item @code{login-options} (default: @code{#f})
12170 This option accepts a string containing options that are passed to the
12171 login program. When used with the @var{login-program}, be aware that a
12172 malicious user could try to enter a login name containing embedded
12173 options that could be parsed by the login program.
12175 @item @code{login-pause} (default: @code{#f})
12176 When set to @code{#t}, wait for any key before showing the login prompt.
12177 This can be used in conjunction with @var{auto-login} to save memory by
12178 lazily spawning shells.
12180 @item @code{chroot} (default: @code{#f})
12181 Change root to the specified directory. This option accepts a directory
12184 @item @code{hangup?} (default: @code{#f})
12185 Use the Linux system call @code{vhangup} to do a virtual hangup of the
12186 specified terminal.
12188 @item @code{keep-baud?} (default: @code{#f})
12189 When set to @code{#t}, try to keep the existing baud rate. The baud
12190 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
12193 @item @code{timeout} (default: @code{#f})
12194 When set to an integer value, terminate if no user name could be read
12195 within @var{timeout} seconds.
12197 @item @code{detect-case?} (default: @code{#f})
12198 When set to @code{#t}, turn on support for detecting an uppercase-only
12199 terminal. This setting will detect a login name containing only
12200 uppercase letters as indicating an uppercase-only terminal and turn on
12201 some upper-to-lower case conversions. Note that this will not support
12202 Unicode characters.
12204 @item @code{wait-cr?} (default: @code{#f})
12205 When set to @code{#t}, wait for the user or modem to send a
12206 carriage-return or linefeed character before displaying
12207 @file{/etc/issue} or login prompt. This is typically used with the
12208 @var{init-string} option.
12210 @item @code{no-hints?} (default: @code{#f})
12211 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
12214 @item @code{no-hostname?} (default: @code{#f})
12215 By default, the hostname is printed. When this option is set to
12216 @code{#t}, no hostname will be shown at all.
12218 @item @code{long-hostname?} (default: @code{#f})
12219 By default, the hostname is only printed until the first dot. When this
12220 option is set to @code{#t}, the fully qualified hostname by
12221 @code{gethostname} or @code{getaddrinfo} is shown.
12223 @item @code{erase-characters} (default: @code{#f})
12224 This option accepts a string of additional characters that should be
12225 interpreted as backspace when the user types their login name.
12227 @item @code{kill-characters} (default: @code{#f})
12228 This option accepts a string that should be interpreted to mean "ignore
12229 all previous characters" (also called a "kill" character) when the user
12230 types their login name.
12232 @item @code{chdir} (default: @code{#f})
12233 This option accepts, as a string, a directory path that will be changed
12236 @item @code{delay} (default: @code{#f})
12237 This options accepts, as an integer, the number of seconds to sleep
12238 before opening the tty and displaying the login prompt.
12240 @item @code{nice} (default: @code{#f})
12241 This option accepts, as an integer, the nice value with which to run the
12242 @command{login} program.
12244 @item @code{extra-options} (default: @code{'()})
12245 This option provides an "escape hatch" for the user to provide arbitrary
12246 command-line arguments to @command{agetty} as a list of strings.
12251 @deffn {Scheme Procedure} kmscon-service-type @var{config}
12252 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
12253 according to @var{config}, a @code{<kmscon-configuration>} object, which
12254 specifies the tty to run, among other things.
12257 @deftp {Data Type} kmscon-configuration
12258 This is the data type representing the configuration of Kmscon, which
12259 implements virtual console log-in.
12263 @item @code{virtual-terminal}
12264 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
12266 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
12267 A gexp denoting the name of the log-in program. The default log-in program is
12268 @command{login} from the Shadow tool suite.
12270 @item @code{login-arguments} (default: @code{'("-p")})
12271 A list of arguments to pass to @command{login}.
12273 @item @code{auto-login} (default: @code{#f})
12274 When passed a login name, as a string, the specified user will be logged
12275 in automatically without prompting for their login name or password.
12277 @item @code{hardware-acceleration?} (default: #f)
12278 Whether to use hardware acceleration.
12280 @item @code{kmscon} (default: @var{kmscon})
12281 The Kmscon package to use.
12286 @cindex name service cache daemon
12288 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
12289 [#:name-services '()]
12290 Return a service that runs the libc name service cache daemon (nscd) with the
12291 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
12292 Service Switch}, for an example.
12294 For convenience, the Shepherd service for nscd provides the following actions:
12298 @cindex cache invalidation, nscd
12299 @cindex nscd, cache invalidation
12300 This invalidate the given cache. For instance, running:
12303 herd invalidate nscd hosts
12307 invalidates the host name lookup cache of nscd.
12310 Running @command{herd statistics nscd} displays information about nscd usage
12316 @defvr {Scheme Variable} %nscd-default-configuration
12317 This is the default @code{<nscd-configuration>} value (see below) used
12318 by @code{nscd-service}. It uses the caches defined by
12319 @var{%nscd-default-caches}; see below.
12322 @deftp {Data Type} nscd-configuration
12323 This is the data type representing the name service cache daemon (nscd)
12328 @item @code{name-services} (default: @code{'()})
12329 List of packages denoting @dfn{name services} that must be visible to
12330 the nscd---e.g., @code{(list @var{nss-mdns})}.
12332 @item @code{glibc} (default: @var{glibc})
12333 Package object denoting the GNU C Library providing the @command{nscd}
12336 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
12337 Name of the nscd log file. This is where debugging output goes when
12338 @code{debug-level} is strictly positive.
12340 @item @code{debug-level} (default: @code{0})
12341 Integer denoting the debugging levels. Higher numbers mean that more
12342 debugging output is logged.
12344 @item @code{caches} (default: @var{%nscd-default-caches})
12345 List of @code{<nscd-cache>} objects denoting things to be cached; see
12351 @deftp {Data Type} nscd-cache
12352 Data type representing a cache database of nscd and its parameters.
12356 @item @code{database}
12357 This is a symbol representing the name of the database to be cached.
12358 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12359 @code{services}, which designate the corresponding NSS database
12360 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12362 @item @code{positive-time-to-live}
12363 @itemx @code{negative-time-to-live} (default: @code{20})
12364 A number representing the number of seconds during which a positive or
12365 negative lookup result remains in cache.
12367 @item @code{check-files?} (default: @code{#t})
12368 Whether to check for updates of the files corresponding to
12371 For instance, when @var{database} is @code{hosts}, setting this flag
12372 instructs nscd to check for updates in @file{/etc/hosts} and to take
12375 @item @code{persistent?} (default: @code{#t})
12376 Whether the cache should be stored persistently on disk.
12378 @item @code{shared?} (default: @code{#t})
12379 Whether the cache should be shared among users.
12381 @item @code{max-database-size} (default: 32@tie{}MiB)
12382 Maximum size in bytes of the database cache.
12384 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12385 @c settings, so leave them out.
12390 @defvr {Scheme Variable} %nscd-default-caches
12391 List of @code{<nscd-cache>} objects used by default by
12392 @code{nscd-configuration} (see above).
12394 It enables persistent and aggressive caching of service and host name
12395 lookups. The latter provides better host name lookup performance,
12396 resilience in the face of unreliable name servers, and also better
12397 privacy---often the result of host name lookups is in local cache, so
12398 external name servers do not even need to be queried.
12401 @anchor{syslog-configuration-type}
12404 @deftp {Data Type} syslog-configuration
12405 This data type represents the configuration of the syslog daemon.
12408 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12409 The syslog daemon to use.
12411 @item @code{config-file} (default: @code{%default-syslog.conf})
12412 The syslog configuration file to use.
12417 @anchor{syslog-service}
12419 @deffn {Scheme Procedure} syslog-service @var{config}
12420 Return a service that runs a syslog daemon according to @var{config}.
12422 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12423 information on the configuration file syntax.
12426 @defvr {Scheme Variable} guix-service-type
12427 This is the type of the service that runs the build daemon,
12428 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12429 @code{guix-configuration} record as described below.
12432 @anchor{guix-configuration-type}
12433 @deftp {Data Type} guix-configuration
12434 This data type represents the configuration of the Guix build daemon.
12435 @xref{Invoking guix-daemon}, for more information.
12438 @item @code{guix} (default: @var{guix})
12439 The Guix package to use.
12441 @item @code{build-group} (default: @code{"guixbuild"})
12442 Name of the group for build user accounts.
12444 @item @code{build-accounts} (default: @code{10})
12445 Number of build user accounts to create.
12447 @item @code{authorize-key?} (default: @code{#t})
12448 @cindex substitutes, authorization thereof
12449 Whether to authorize the substitute keys listed in
12450 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12451 (@pxref{Substitutes}).
12453 @vindex %default-authorized-guix-keys
12454 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12455 The list of authorized key files for archive imports, as a list of
12456 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12457 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12459 @item @code{use-substitutes?} (default: @code{#t})
12460 Whether to use substitutes.
12462 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12463 The list of URLs where to look for substitutes by default.
12465 @item @code{max-silent-time} (default: @code{0})
12466 @itemx @code{timeout} (default: @code{0})
12467 The number of seconds of silence and the number of seconds of activity,
12468 respectively, after which a build process times out. A value of zero
12469 disables the timeout.
12471 @item @code{log-compression} (default: @code{'bzip2})
12472 The type of compression used for build logs---one of @code{gzip},
12473 @code{bzip2}, or @code{none}.
12475 @item @code{extra-options} (default: @code{'()})
12476 List of extra command-line options for @command{guix-daemon}.
12478 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12479 File where @command{guix-daemon}'s standard output and standard error
12482 @item @code{http-proxy} (default: @code{#f})
12483 The HTTP proxy used for downloading fixed-output derivations and
12486 @item @code{tmpdir} (default: @code{#f})
12487 A directory path where the @command{guix-daemon} will perform builds.
12492 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12493 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12494 udev rules can be provided as a list of files through the @var{rules}
12495 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12496 @code{(gnu services base)} simplify the creation of such rule files.
12499 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12500 Return a udev-rule file named @var{file-name} containing the rules
12501 defined by the @var{contents} literal.
12503 In the following example, a rule for a USB device is defined to be
12504 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12505 upon detecting a USB device with a given product identifier.
12508 (define %example-udev-rule
12510 "90-usb-thing.rules"
12511 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12512 "ATTR@{product@}==\"Example\", "
12513 "RUN+=\"/path/to/script\"")))
12516 The @command{herd rules udev} command, as root, returns the name of the
12517 directory containing all the active udev rules.
12520 Here we show how the default @var{udev-service} can be extended with it.
12526 (modify-services %desktop-services
12527 (udev-service-type config =>
12528 (udev-configuration (inherit config)
12529 (rules (append (udev-configuration-rules config)
12530 (list %example-udev-rule))))))))
12533 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12534 Return a udev file named @var{file-name} containing the rules defined
12535 within @var{file}, a file-like object.
12537 The following example showcases how we can use an existing rule file.
12540 (use-modules (guix download) ;for url-fetch
12541 (guix packages) ;for origin
12544 (define %android-udev-rules
12546 "51-android-udev.rules"
12547 (let ((version "20170910"))
12550 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12551 "android-udev-rules/" version "/51-android.rules"))
12553 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12557 Additionally, Guix package definitions can be included in @var{rules} in
12558 order to extend the udev rules with the definitions found under their
12559 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12560 @var{file->udev-rule} example, we could have used the
12561 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12562 packages android)} module.
12564 The following example shows how to use the @var{android-udev-rules}
12565 package so that the Android tool @command{adb} can detect devices
12566 without root privileges. It also details how to create the
12567 @code{adbusers} group, which is required for the proper functioning of
12568 the rules defined within the @var{android-udev-rules} package. To
12569 create such a group, we must define it both as part of the
12570 @var{supplementary-groups} of our @var{user-account} declaration, as
12571 well as in the @var{groups} field of the @var{operating-system} record.
12574 (use-modules (gnu packages android) ;for android-udev-rules
12575 (gnu system shadow) ;for user-group
12580 (users (cons (user-acount
12582 (supplementary-groups
12583 '("adbusers" ;for adb
12584 "wheel" "netdev" "audio" "video")))))
12586 (groups (cons (user-group (system? #t) (name "adbusers"))
12592 (modify-services %desktop-services
12595 (udev-configuration (inherit config)
12596 (rules (cons android-udev-rules
12597 (udev-configuration-rules config))))))))
12600 @defvr {Scheme Variable} urandom-seed-service-type
12601 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12602 when rebooting. It also tries to seed @file{/dev/urandom} from
12603 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12607 @defvr {Scheme Variable} %random-seed-file
12608 This is the name of the file where some random bytes are saved by
12609 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12610 It defaults to @file{/var/lib/random-seed}.
12615 @defvr {Scheme Variable} gpm-service-type
12616 This is the type of the service that runs GPM, the @dfn{general-purpose
12617 mouse daemon}, which provides mouse support to the Linux console. GPM
12618 allows users to use the mouse in the console, notably to select, copy,
12621 The value for services of this type must be a @code{gpm-configuration}
12622 (see below). This service is not part of @code{%base-services}.
12625 @deftp {Data Type} gpm-configuration
12626 Data type representing the configuration of GPM.
12629 @item @code{options} (default: @code{%default-gpm-options})
12630 Command-line options passed to @command{gpm}. The default set of
12631 options instruct @command{gpm} to listen to mouse events on
12632 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12635 @item @code{gpm} (default: @code{gpm})
12636 The GPM package to use.
12641 @anchor{guix-publish-service-type}
12642 @deffn {Scheme Variable} guix-publish-service-type
12643 This is the service type for @command{guix publish} (@pxref{Invoking
12644 guix publish}). Its value must be a @code{guix-publish-configuration}
12645 object, as described below.
12647 This assumes that @file{/etc/guix} already contains a signing key pair as
12648 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12649 archive}). If that is not the case, the service will fail to start.
12652 @deftp {Data Type} guix-publish-configuration
12653 Data type representing the configuration of the @code{guix publish}
12657 @item @code{guix} (default: @code{guix})
12658 The Guix package to use.
12660 @item @code{port} (default: @code{80})
12661 The TCP port to listen for connections.
12663 @item @code{host} (default: @code{"localhost"})
12664 The host (and thus, network interface) to listen to. Use
12665 @code{"0.0.0.0"} to listen on all the network interfaces.
12667 @item @code{compression} (default: @code{'(("gzip" 3))})
12668 This is a list of compression method/level tuple used when compressing
12669 substitutes. For example, to compress all substitutes with @emph{both} lzip
12670 at level 7 and gzip at level 9, write:
12673 '(("lzip" 7) ("gzip" 9))
12676 Level 9 achieves the best compression ratio at the expense of increased CPU
12677 usage, whereas level 1 achieves fast compression.
12679 An empty list disables compression altogether.
12681 @item @code{nar-path} (default: @code{"nar"})
12682 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12683 publish, @code{--nar-path}}, for details.
12685 @item @code{cache} (default: @code{#f})
12686 When it is @code{#f}, disable caching and instead generate archives on
12687 demand. Otherwise, this should be the name of a directory---e.g.,
12688 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12689 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12690 @option{--cache}}, for more information on the tradeoffs involved.
12692 @item @code{workers} (default: @code{#f})
12693 When it is an integer, this is the number of worker threads used for
12694 caching; when @code{#f}, the number of processors is used.
12695 @xref{Invoking guix publish, @option{--workers}}, for more information.
12697 @item @code{ttl} (default: @code{#f})
12698 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12699 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12700 for more information.
12704 @anchor{rngd-service}
12705 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12706 [#:device "/dev/hwrng"]
12707 Return a service that runs the @command{rngd} program from @var{rng-tools}
12708 to add @var{device} to the kernel's entropy pool. The service will fail if
12709 @var{device} does not exist.
12712 @anchor{pam-limits-service}
12713 @cindex session limits
12718 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12720 Return a service that installs a configuration file for the
12721 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12722 @code{pam_limits} module}. The procedure optionally takes a list of
12723 @code{pam-limits-entry} values, which can be used to specify
12724 @code{ulimit} limits and nice priority limits to user sessions.
12726 The following limits definition sets two hard and soft limits for all
12727 login sessions of users in the @code{realtime} group:
12730 (pam-limits-service
12732 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12733 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12736 The first entry increases the maximum realtime priority for
12737 non-privileged processes; the second entry lifts any restriction of the
12738 maximum address space that can be locked in memory. These settings are
12739 commonly used for real-time audio systems.
12742 @node Scheduled Job Execution
12743 @subsection Scheduled Job Execution
12747 @cindex scheduling jobs
12748 The @code{(gnu services mcron)} module provides an interface to
12749 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12750 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12751 Unix @command{cron} daemon; the main difference is that it is
12752 implemented in Guile Scheme, which provides a lot of flexibility when
12753 specifying the scheduling of jobs and their actions.
12755 The example below defines an operating system that runs the
12756 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12757 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12758 well as the @command{mkid} command on behalf of an unprivileged user
12759 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12760 gexps to introduce job definitions that are passed to mcron
12761 (@pxref{G-Expressions}).
12764 (use-modules (guix) (gnu) (gnu services mcron))
12765 (use-package-modules base idutils)
12767 (define updatedb-job
12768 ;; Run 'updatedb' at 3AM every day. Here we write the
12769 ;; job's action as a Scheme procedure.
12770 #~(job '(next-hour '(3))
12772 (execl (string-append #$findutils "/bin/updatedb")
12774 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12776 (define garbage-collector-job
12777 ;; Collect garbage 5 minutes after midnight every day.
12778 ;; The job's action is a shell command.
12779 #~(job "5 0 * * *" ;Vixie cron syntax
12782 (define idutils-job
12783 ;; Update the index database as user "charlie" at 12:15PM
12784 ;; and 19:15PM. This runs from the user's home directory.
12785 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12786 (string-append #$idutils "/bin/mkid src")
12791 (services (cons (service mcron-service-type
12792 (mcron-configuration
12793 (jobs (list garbage-collector-job
12799 For more complex jobs defined in Scheme where you need control over the top
12800 level, for instance to introduce a @code{use-modules} form, you can move your
12801 code to a separate program using the @code{program-file} procedure of the
12802 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
12806 (define %battery-alert-job
12807 ;; Beep when the battery percentage falls below %MIN-LEVEL.
12809 '(next-minute (range 0 60 1))
12811 "battery-alert.scm"
12812 (with-imported-modules (source-module-closure
12813 '((guix build utils)))
12815 (define %min-level 20)
12816 (use-modules (guix build utils)
12819 (ice-9 textual-ports)
12821 (setenv "LC_ALL" "C") ;ensure English output
12822 (and-let* ((input-pipe (open-pipe*
12824 #$(file-append acpi "/bin/acpi")))
12825 (output (get-string-all input-pipe))
12826 (m (string-match "Discharging, ([0-9]+)%" output))
12827 (level (string->number (match:substring m 1)))
12828 ((< level %min-level)))
12829 (format #t "warning: Battery level is low (~a%)~%" level)
12830 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
12833 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12834 for more information on mcron job specifications. Below is the
12835 reference of the mcron service.
12837 On a running system, you can use the @code{schedule} action of the service to
12838 visualize the mcron jobs that will be executed next:
12841 # herd schedule mcron
12845 The example above lists the next five tasks that will be executed, but you can
12846 also specify the number of tasks to display:
12849 # herd schedule mcron 10
12852 @defvr {Scheme Variable} mcron-service-type
12853 This is the type of the @code{mcron} service, whose value is an
12854 @code{mcron-configuration} object.
12856 This service type can be the target of a service extension that provides
12857 it additional job specifications (@pxref{Service Composition}). In
12858 other words, it is possible to define services that provide additional
12862 @deftp {Data Type} mcron-configuration
12863 Data type representing the configuration of mcron.
12866 @item @code{mcron} (default: @var{mcron})
12867 The mcron package to use.
12870 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12871 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12872 specifications,, mcron, GNU@tie{}mcron}).
12878 @subsection Log Rotation
12881 @cindex log rotation
12883 Log files such as those found in @file{/var/log} tend to grow endlessly,
12884 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12885 their contents in separate files, possibly compressed. The @code{(gnu
12886 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12887 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12889 The example below defines an operating system that provides log rotation
12890 with the default settings, for commonly encountered log files.
12893 (use-modules (guix) (gnu))
12894 (use-service-modules admin mcron)
12895 (use-package-modules base idutils)
12899 (services (cons (service rottlog-service-type)
12903 @defvr {Scheme Variable} rottlog-service-type
12904 This is the type of the Rottlog service, whose value is a
12905 @code{rottlog-configuration} object.
12907 Other services can extend this one with new @code{log-rotation} objects
12908 (see below), thereby augmenting the set of files to be rotated.
12910 This service type can define mcron jobs (@pxref{Scheduled Job
12911 Execution}) to run the rottlog service.
12914 @deftp {Data Type} rottlog-configuration
12915 Data type representing the configuration of rottlog.
12918 @item @code{rottlog} (default: @code{rottlog})
12919 The Rottlog package to use.
12921 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12922 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12923 rottlog, GNU Rot[t]log Manual}).
12925 @item @code{rotations} (default: @code{%default-rotations})
12926 A list of @code{log-rotation} objects as defined below.
12929 This is a list of gexps where each gexp corresponds to an mcron job
12930 specification (@pxref{Scheduled Job Execution}).
12934 @deftp {Data Type} log-rotation
12935 Data type representing the rotation of a group of log files.
12937 Taking an example from the Rottlog manual (@pxref{Period Related File
12938 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12944 (files '("/var/log/apache/*"))
12945 (options '("storedir apache-archives"
12951 The list of fields is as follows:
12954 @item @code{frequency} (default: @code{'weekly})
12955 The log rotation frequency, a symbol.
12958 The list of files or file glob patterns to rotate.
12960 @item @code{options} (default: @code{'()})
12961 The list of rottlog options for this rotation (@pxref{Configuration
12962 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12964 @item @code{post-rotate} (default: @code{#f})
12965 Either @code{#f} or a gexp to execute once the rotation has completed.
12969 @defvr {Scheme Variable} %default-rotations
12970 Specifies weekly rotation of @var{%rotated-files} and of
12971 @file{/var/log/guix-daemon.log}.
12974 @defvr {Scheme Variable} %rotated-files
12975 The list of syslog-controlled files to be rotated. By default it is:
12976 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
12977 "/var/log/maillog")}.
12980 @node Networking Services
12981 @subsection Networking Services
12983 The @code{(gnu services networking)} module provides services to configure
12984 the network interface.
12986 @cindex DHCP, networking service
12987 @defvr {Scheme Variable} dhcp-client-service-type
12988 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12989 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12990 is the DHCP client package to use, @code{isc-dhcp} by default.
12993 @deffn {Scheme Procedure} dhcpd-service-type
12994 This type defines a service that runs a DHCP daemon. To create a
12995 service of this type, you must supply a @code{<dhcpd-configuration>}.
12999 (service dhcpd-service-type
13000 (dhcpd-configuration
13001 (config-file (local-file "my-dhcpd.conf"))
13002 (interfaces '("enp0s25"))))
13006 @deftp {Data Type} dhcpd-configuration
13008 @item @code{package} (default: @code{isc-dhcp})
13009 The package that provides the DHCP daemon. This package is expected to
13010 provide the daemon at @file{sbin/dhcpd} relative to its output
13011 directory. The default package is the
13012 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
13013 @item @code{config-file} (default: @code{#f})
13014 The configuration file to use. This is required. It will be passed to
13015 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
13016 object (@pxref{G-Expressions, file-like objects}). See @code{man
13017 dhcpd.conf} for details on the configuration file syntax.
13018 @item @code{version} (default: @code{"4"})
13019 The DHCP version to use. The ISC DHCP server supports the values ``4'',
13020 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
13021 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
13023 @item @code{run-directory} (default: @code{"/run/dhcpd"})
13024 The run directory to use. At service activation time, this directory
13025 will be created if it does not exist.
13026 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
13027 The PID file to use. This corresponds to the @code{-pf} option of
13028 @code{dhcpd}. See @code{man dhcpd} for details.
13029 @item @code{interfaces} (default: @code{'()})
13030 The names of the network interfaces on which dhcpd should listen for
13031 broadcasts. If this list is not empty, then its elements (which must be
13032 strings) will be appended to the @code{dhcpd} invocation when starting
13033 the daemon. It may not be necessary to explicitly specify any
13034 interfaces here; see @code{man dhcpd} for details.
13038 @defvr {Scheme Variable} static-networking-service-type
13039 This is the type for statically-configured network interfaces.
13040 @c TODO Document <static-networking> data structures.
13043 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
13044 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
13045 [#:requirement @code{'(udev)}]
13046 Return a service that starts @var{interface} with address @var{ip}. If
13047 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
13048 it must be a string specifying the default network gateway. @var{requirement}
13049 can be used to declare a dependency on another service before configuring the
13052 This procedure can be called several times, one for each network
13053 interface of interest. Behind the scenes what it does is extend
13054 @code{static-networking-service-type} with additional network interfaces
13060 (static-networking-service "eno1" "192.168.1.82"
13061 #:gateway "192.168.1.2"
13062 #:name-servers '("192.168.1.2"))
13069 @cindex network management
13070 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
13071 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
13072 management daemon that aims to simplify wired and wireless networking.
13074 This service adds the @var{wicd} package to the global profile, providing
13075 several commands to interact with the daemon and configure networking:
13076 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
13077 and @command{wicd-curses} user interfaces.
13080 @cindex ModemManager
13082 @defvr {Scheme Variable} modem-manager-service-type
13083 This is the service type for the
13084 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
13085 service. The value for this service type is a
13086 @code{modem-manager-configuration} record.
13088 This service is part of @code{%desktop-services} (@pxref{Desktop
13092 @deftp {Data Type} modem-manager-configuration
13093 Data type representing the configuration of ModemManager.
13096 @item @code{modem-manager} (default: @code{modem-manager})
13097 The ModemManager package to use.
13102 @cindex USB_ModeSwitch
13103 @cindex Modeswitching
13105 @defvr {Scheme Variable} usb-modeswitch-service-type
13106 This is the service type for the
13107 @uref{http://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
13108 value for this service type is a @code{usb-modeswitch-configuration} record.
13110 When plugged in, some USB modems (and other USB devices) initially present
13111 themselves as a read-only storage medium and not as a modem. They need to be
13112 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
13113 installs udev rules to automatically modeswitch these devices when they are
13116 This service is part of @code{%desktop-services} (@pxref{Desktop
13120 @deftp {Data Type} usb-modeswitch-configuration
13121 Data type representing the configuration of USB_ModeSwitch.
13124 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
13125 The USB_ModeSwitch package providing the binaries for modeswitching.
13127 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
13128 The package providing the device data and udev rules file used by
13131 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
13132 Which config file to use for the USB_ModeSwitch dispatcher. By default the
13133 config file shipped with USB_ModeSwitch is used which disables logging to
13134 @file{/var/log} among other default settings. If set to @code{#f}, no config
13140 @cindex NetworkManager
13142 @defvr {Scheme Variable} network-manager-service-type
13143 This is the service type for the
13144 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
13145 service. The value for this service type is a
13146 @code{network-manager-configuration} record.
13148 This service is part of @code{%desktop-services} (@pxref{Desktop
13152 @deftp {Data Type} network-manager-configuration
13153 Data type representing the configuration of NetworkManager.
13156 @item @code{network-manager} (default: @code{network-manager})
13157 The NetworkManager package to use.
13159 @item @code{dns} (default: @code{"default"})
13160 Processing mode for DNS, which affects how NetworkManager uses the
13161 @code{resolv.conf} configuration file.
13165 NetworkManager will update @code{resolv.conf} to reflect the nameservers
13166 provided by currently active connections.
13169 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
13170 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
13171 then update @code{resolv.conf} to point to the local nameserver.
13173 With this setting, you can share your network connection. For example when
13174 you want to share your network connection to another laptop @i{via} an
13175 Ethernet cable, you can open @command{nm-connection-editor} and configure the
13176 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
13177 and reestablish the connection (or reboot).
13179 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
13180 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
13181 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
13182 browser on your host system, or connect to the VM @i{via} SSH
13183 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
13184 host-to-guest connection, run this command once:
13187 nmcli connection add type tun \
13188 connection.interface-name tap0 \
13189 tun.mode tap tun.owner $(id -u) \
13190 ipv4.method shared \
13191 ipv4.addresses 172.28.112.1/24
13194 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
13195 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
13196 @command{qemu-system-...}.
13199 NetworkManager will not modify @code{resolv.conf}.
13202 @item @code{vpn-plugins} (default: @code{'()})
13203 This is the list of available plugins for virtual private networks
13204 (VPNs). An example of this is the @code{network-manager-openvpn}
13205 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
13211 @deffn {Scheme Variable} connman-service-type
13212 This is the service type to run @url{https://01.org/connman,Connman},
13213 a network connection manager.
13215 Its value must be an
13216 @code{connman-configuration} record as in this example:
13219 (service connman-service-type
13220 (connman-configuration
13221 (disable-vpn? #t)))
13224 See below for details about @code{connman-configuration}.
13227 @deftp {Data Type} connman-configuration
13228 Data Type representing the configuration of connman.
13231 @item @code{connman} (default: @var{connman})
13232 The connman package to use.
13234 @item @code{disable-vpn?} (default: @code{#f})
13235 When true, disable connman's vpn plugin.
13239 @cindex WPA Supplicant
13240 @defvr {Scheme Variable} wpa-supplicant-service-type
13241 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
13242 supplicant}, an authentication daemon required to authenticate against
13243 encrypted WiFi or ethernet networks.
13246 @deftp {Data Type} wpa-supplicant-configuration
13247 Data type representing the configuration of WPA Supplicant.
13249 It takes the following parameters:
13252 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
13253 The WPA Supplicant package to use.
13255 @item @code{dbus?} (default: @code{#t})
13256 Whether to listen for requests on D-Bus.
13258 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
13259 Where to store the PID file.
13261 @item @code{interface} (default: @code{#f})
13262 If this is set, it must specify the name of a network interface that
13263 WPA supplicant will control.
13265 @item @code{config-file} (default: @code{#f})
13266 Optional configuration file to use.
13268 @item @code{extra-options} (default: @code{'()})
13269 List of additional command-line arguments to pass to the daemon.
13274 @defvr {Scheme Variable} iptables-service-type
13275 This is the service type to set up an iptables configuration. iptables is a
13276 packet filtering framework supported by the Linux kernel. This service
13277 supports configuring iptables for both IPv4 and IPv6. A simple example
13278 configuration rejecting all incoming connections except those to the ssh port
13282 (service iptables-service-type
13283 (iptables-configuration
13284 (ipv4-rules (plain-file "iptables.rules" "*filter
13288 -A INPUT -p tcp --dport 22 -j ACCEPT
13289 -A INPUT -j REJECT --reject-with icmp-port-unreachable
13292 (ipv6-rules (plain-file "ip6tables.rules" "*filter
13296 -A INPUT -p tcp --dport 22 -j ACCEPT
13297 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
13303 @deftp {Data Type} iptables-configuration
13304 The data type representing the configuration of iptables.
13307 @item @code{iptables} (default: @code{iptables})
13308 The iptables package that provides @code{iptables-restore} and
13309 @code{ip6tables-restore}.
13310 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
13311 The iptables rules to use. It will be passed to @code{iptables-restore}.
13312 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13314 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
13315 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
13316 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13322 @defvr {Scheme Variable} nftables-service-type
13323 This is the service type to set up a nftables configuration. nftables is a
13324 netfilter project that aims to replace the existing iptables, ip6tables,
13325 arptables and ebtables framework. It provides a new packet filtering
13326 framework, a new user-space utility @command{nft}, and a compatibility layer
13327 for iptables. This service comes with a default ruleset
13328 @code{%default-nftables-ruleset} that rejecting all incomming connections
13329 except those to the ssh port 22. To use it, simply write:
13332 (service nftables-service-type)
13336 @deftp {Data Type} nftables-configuration
13337 The data type representing the configuration of nftables.
13340 @item @code{package} (default: @code{nftables})
13341 The nftables package that provides @command{nft}.
13342 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
13343 The nftables ruleset to use. This may be any ``file-like'' object
13344 (@pxref{G-Expressions, file-like objects}).
13348 @cindex NTP (Network Time Protocol), service
13349 @cindex ntpd, service for the Network Time Protocol daemon
13350 @cindex real time clock
13351 @defvr {Scheme Variable} ntp-service-type
13352 This is the type of the service running the @uref{http://www.ntp.org,
13353 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
13354 system clock synchronized with that of the specified NTP servers.
13356 The value of this service is an @code{ntpd-configuration} object, as described
13360 @deftp {Data Type} ntp-configuration
13361 This is the data type for the NTP service configuration.
13364 @item @code{servers} (default: @code{%ntp-servers})
13365 This is the list of servers (@code{<ntp-server>} records) with which
13366 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
13369 @item @code{allow-large-adjustment?} (default: @code{#t})
13370 This determines whether @command{ntpd} is allowed to make an initial
13371 adjustment of more than 1,000 seconds.
13373 @item @code{ntp} (default: @code{ntp})
13374 The NTP package to use.
13378 @defvr {Scheme Variable} %ntp-servers
13379 List of host names used as the default NTP servers. These are servers of the
13380 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13383 @deftp {Data Type} ntp-server
13384 The data type representing the configuration of a NTP server.
13387 @item @code{type} (default: @code{'server})
13388 The type of the NTP server, given as a symbol. One of @code{'pool},
13389 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
13391 @item @code{address}
13392 The address of the server, as a string.
13394 @item @code{options}
13395 NTPD options to use with that specific server, given as a list of option names
13396 and/or of option names and values tuples. The following example define a server
13397 to use with the options @option{iburst} and @option{prefer}, as well as
13398 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
13403 (address "some.ntp.server.org")
13404 (options `(iburst (version 3) (maxpoll 16) prefer))))
13410 @deffn {Scheme Procedure} openntpd-service-type
13411 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13412 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13413 clock synchronized with that of the given servers.
13417 openntpd-service-type
13418 (openntpd-configuration
13419 (listen-on '("127.0.0.1" "::1"))
13420 (sensor '("udcf0 correction 70000"))
13421 (constraint-from '("www.gnu.org"))
13422 (constraints-from '("https://www.google.com/"))
13423 (allow-large-adjustment? #t)))
13428 @defvr {Scheme Variable} %openntpd-servers
13429 This variable is a list of the server addresses defined in
13430 @var{%ntp-servers}.
13433 @deftp {Data Type} openntpd-configuration
13435 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13436 The openntpd executable to use.
13437 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13438 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13439 @item @code{query-from} (default: @code{'()})
13440 A list of local IP address the ntpd daemon should use for outgoing queries.
13441 @item @code{sensor} (default: @code{'()})
13442 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13443 will listen to each sensor that actually exists and ignore non-existent ones.
13444 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13446 @item @code{server} (default: @code{'()})
13447 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13448 @item @code{servers} (default: @var{%openntp-servers})
13449 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13450 @item @code{constraint-from} (default: @code{'()})
13451 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13452 This time information is not used for precision but acts as an authenticated
13453 constraint, thereby reducing the impact of unauthenticated NTP
13454 man-in-the-middle attacks.
13455 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
13457 @item @code{constraints-from} (default: @code{'()})
13458 As with constraint from, specify a list of URLs, IP addresses or hostnames of
13459 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
13460 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
13461 @item @code{allow-large-adjustment?} (default: @code{#f})
13462 Determines if @code{ntpd} is allowed to make an initial adjustment of more
13468 @deffn {Scheme variable} inetd-service-type
13469 This service runs the @command{inetd} (@pxref{inetd invocation,,,
13470 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
13471 connections on internet sockets, and lazily starts the specified server
13472 program when a connection is made on one of these sockets.
13474 The value of this service is an @code{inetd-configuration} object. The
13475 following example configures the @command{inetd} daemon to provide the
13476 built-in @command{echo} service, as well as an smtp service which
13477 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13478 gateway @code{hostname}:
13483 (inetd-configuration
13487 (socket-type 'stream)
13494 (socket-type 'stream)
13498 (program (file-append openssh "/bin/ssh"))
13500 '("ssh" "-qT" "-i" "/path/to/ssh_key"
13501 "-W" "smtp-server:25" "user@@hostname")))))))
13504 See below for more details about @code{inetd-configuration}.
13507 @deftp {Data Type} inetd-configuration
13508 Data type representing the configuration of @command{inetd}.
13511 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
13512 The @command{inetd} executable to use.
13514 @item @code{entries} (default: @code{'()})
13515 A list of @command{inetd} service entries. Each entry should be created
13516 by the @code{inetd-entry} constructor.
13520 @deftp {Data Type} inetd-entry
13521 Data type representing an entry in the @command{inetd} configuration.
13522 Each entry corresponds to a socket where @command{inetd} will listen for
13526 @item @code{node} (default: @code{#f})
13527 Optional string, a comma-separated list of local addresses
13528 @command{inetd} should use when listening for this service.
13529 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13530 description of all options.
13532 A string, the name must correspond to an entry in @code{/etc/services}.
13533 @item @code{socket-type}
13534 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13536 @item @code{protocol}
13537 A string, must correspond to an entry in @code{/etc/protocols}.
13538 @item @code{wait?} (default: @code{#t})
13539 Whether @command{inetd} should wait for the server to exit before
13540 listening to new service requests.
13542 A string containing the user (and, optionally, group) name of the user
13543 as whom the server should run. The group name can be specified in a
13544 suffix, separated by a colon or period, i.e.@: @code{"user"},
13545 @code{"user:group"} or @code{"user.group"}.
13546 @item @code{program} (default: @code{"internal"})
13547 The server program which will serve the requests, or @code{"internal"}
13548 if @command{inetd} should use a built-in service.
13549 @item @code{arguments} (default: @code{'()})
13550 A list strings or file-like objects, which are the server program's
13551 arguments, starting with the zeroth argument, i.e.@: the name of the
13552 program itself. For @command{inetd}'s internal services, this entry
13553 must be @code{'()} or @code{'("internal")}.
13556 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
13557 detailed discussion of each configuration field.
13561 @defvr {Scheme Variable} tor-service-type
13562 This is the type for a service that runs the @uref{https://torproject.org,
13563 Tor} anonymous networking daemon. The service is configured using a
13564 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
13565 @code{tor} unprivileged user, which is a member of the @code{tor} group.
13569 @deftp {Data Type} tor-configuration
13571 @item @code{tor} (default: @code{tor})
13572 The package that provides the Tor daemon. This package is expected to provide
13573 the daemon at @file{bin/tor} relative to its output directory. The default
13574 package is the @uref{https://www.torproject.org, Tor Project's}
13577 @item @code{config-file} (default: @code{(plain-file "empty" "")})
13578 The configuration file to use. It will be appended to a default configuration
13579 file, and the final configuration file will be passed to @code{tor} via its
13580 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
13581 file-like objects}). See @code{man tor} for details on the configuration file
13584 @item @code{hidden-services} (default: @code{'()})
13585 The list of @code{<hidden-service>} records to use. For any hidden service
13586 you include in this list, appropriate configuration to enable the hidden
13587 service will be automatically added to the default configuration file. You
13588 may conveniently create @code{<hidden-service>} records using the
13589 @code{tor-hidden-service} procedure described below.
13591 @item @code{socks-socket-type} (default: @code{'tcp})
13592 The default socket type that Tor should use for its SOCKS socket. This must
13593 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
13594 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
13595 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
13596 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
13599 If you want to customize the SOCKS socket in more detail, leave
13600 @code{socks-socket-type} at its default value of @code{'tcp} and use
13601 @code{config-file} to override the default by providing your own
13602 @code{SocksPort} option.
13606 @cindex hidden service
13607 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
13608 Define a new Tor @dfn{hidden service} called @var{name} and implementing
13609 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
13612 '((22 "127.0.0.1:22")
13613 (80 "127.0.0.1:8080"))
13616 In this example, port 22 of the hidden service is mapped to local port 22, and
13617 port 80 is mapped to local port 8080.
13619 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13620 the @file{hostname} file contains the @code{.onion} host name for the hidden
13623 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13624 project's documentation} for more information.
13627 The @code{(gnu services rsync)} module provides the following services:
13629 You might want an rsync daemon if you have files that you want available
13630 so anyone (or just yourself) can download existing files or upload new
13633 @deffn {Scheme Variable} rsync-service-type
13634 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13635 The value for this service type is a
13636 @command{rsync-configuration} record as in this example:
13639 (service rsync-service-type)
13642 See below for details about @code{rsync-configuration}.
13645 @deftp {Data Type} rsync-configuration
13646 Data type representing the configuration for @code{rsync-service}.
13649 @item @code{package} (default: @var{rsync})
13650 @code{rsync} package to use.
13652 @item @code{port-number} (default: @code{873})
13653 TCP port on which @command{rsync} listens for incoming connections. If port
13654 is less than @code{1024} @command{rsync} needs to be started as the
13655 @code{root} user and group.
13657 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13658 Name of the file where @command{rsync} writes its PID.
13660 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13661 Name of the file where @command{rsync} writes its lock file.
13663 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13664 Name of the file where @command{rsync} writes its log file.
13666 @item @code{use-chroot?} (default: @var{#t})
13667 Whether to use chroot for @command{rsync} shared directory.
13669 @item @code{share-path} (default: @file{/srv/rsync})
13670 Location of the @command{rsync} shared directory.
13672 @item @code{share-comment} (default: @code{"Rsync share"})
13673 Comment of the @command{rsync} shared directory.
13675 @item @code{read-only?} (default: @var{#f})
13676 Read-write permissions to shared directory.
13678 @item @code{timeout} (default: @code{300})
13679 I/O timeout in seconds.
13681 @item @code{user} (default: @var{"root"})
13682 Owner of the @code{rsync} process.
13684 @item @code{group} (default: @var{"root"})
13685 Group of the @code{rsync} process.
13687 @item @code{uid} (default: @var{"rsyncd"})
13688 User name or user ID that file transfers to and from that module should take
13689 place as when the daemon was run as @code{root}.
13691 @item @code{gid} (default: @var{"rsyncd"})
13692 Group name or group ID that will be used when accessing the module.
13697 Furthermore, @code{(gnu services ssh)} provides the following services.
13701 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13702 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13703 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13704 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13705 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13706 [#:public-key-authentication? #t] [#:initialize? #t]
13707 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13708 @var{host-key} must designate a file containing the host key, and readable
13711 When @var{daemonic?} is true, @command{lshd} will detach from the
13712 controlling terminal and log its output to syslogd, unless one sets
13713 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13714 depend on existence of syslogd service. When @var{pid-file?} is true,
13715 @command{lshd} writes its PID to the file called @var{pid-file}.
13717 When @var{initialize?} is true, automatically create the seed and host key
13718 upon service activation if they do not exist yet. This may take long and
13719 require interaction.
13721 When @var{initialize?} is false, it is up to the user to initialize the
13722 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13723 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13724 basics,,, lsh, LSH Manual}).
13726 When @var{interfaces} is empty, lshd listens for connections on all the
13727 network interfaces; otherwise, @var{interfaces} must be a list of host names
13730 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13731 passwords, and @var{root-login?} specifies whether to accept log-ins as
13734 The other options should be self-descriptive.
13739 @deffn {Scheme Variable} openssh-service-type
13740 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13741 shell daemon, @command{sshd}. Its value must be an
13742 @code{openssh-configuration} record as in this example:
13745 (service openssh-service-type
13746 (openssh-configuration
13747 (x11-forwarding? #t)
13748 (permit-root-login 'without-password)
13750 `(("alice" ,(local-file "alice.pub"))
13751 ("bob" ,(local-file "bob.pub"))))))
13754 See below for details about @code{openssh-configuration}.
13756 This service can be extended with extra authorized keys, as in this
13760 (service-extension openssh-service-type
13761 (const `(("charlie"
13762 ,(local-file "charlie.pub")))))
13766 @deftp {Data Type} openssh-configuration
13767 This is the configuration record for OpenSSH's @command{sshd}.
13770 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13771 Name of the file where @command{sshd} writes its PID.
13773 @item @code{port-number} (default: @code{22})
13774 TCP port on which @command{sshd} listens for incoming connections.
13776 @item @code{permit-root-login} (default: @code{#f})
13777 This field determines whether and when to allow logins as root. If
13778 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13779 If it's the symbol @code{'without-password}, then root logins are
13780 permitted but not with password-based authentication.
13782 @item @code{allow-empty-passwords?} (default: @code{#f})
13783 When true, users with empty passwords may log in. When false, they may
13786 @item @code{password-authentication?} (default: @code{#t})
13787 When true, users may log in with their password. When false, they have
13788 other authentication methods.
13790 @item @code{public-key-authentication?} (default: @code{#t})
13791 When true, users may log in using public key authentication. When
13792 false, users have to use other authentication method.
13794 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13795 This is used only by protocol version 2.
13797 @item @code{x11-forwarding?} (default: @code{#f})
13798 When true, forwarding of X11 graphical client connections is
13799 enabled---in other words, @command{ssh} options @option{-X} and
13800 @option{-Y} will work.
13802 @item @code{allow-agent-forwarding?} (default: @code{#t})
13803 Whether to allow agent forwarding.
13805 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13806 Whether to allow TCP forwarding.
13808 @item @code{gateway-ports?} (default: @code{#f})
13809 Whether to allow gateway ports.
13811 @item @code{challenge-response-authentication?} (default: @code{#f})
13812 Specifies whether challenge response authentication is allowed (e.g.@: via
13815 @item @code{use-pam?} (default: @code{#t})
13816 Enables the Pluggable Authentication Module interface. If set to
13817 @code{#t}, this will enable PAM authentication using
13818 @code{challenge-response-authentication?} and
13819 @code{password-authentication?}, in addition to PAM account and session
13820 module processing for all authentication types.
13822 Because PAM challenge response authentication usually serves an
13823 equivalent role to password authentication, you should disable either
13824 @code{challenge-response-authentication?} or
13825 @code{password-authentication?}.
13827 @item @code{print-last-log?} (default: @code{#t})
13828 Specifies whether @command{sshd} should print the date and time of the
13829 last user login when a user logs in interactively.
13831 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13832 Configures external subsystems (e.g.@: file transfer daemon).
13834 This is a list of two-element lists, each of which containing the
13835 subsystem name and a command (with optional arguments) to execute upon
13838 The command @command{internal-sftp} implements an in-process SFTP
13839 server. Alternately, one can specify the @command{sftp-server} command:
13841 (service openssh-service-type
13842 (openssh-configuration
13844 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13847 @item @code{accepted-environment} (default: @code{'()})
13848 List of strings describing which environment variables may be exported.
13850 Each string gets on its own line. See the @code{AcceptEnv} option in
13851 @code{man sshd_config}.
13853 This example allows ssh-clients to export the @code{COLORTERM} variable.
13854 It is set by terminal emulators, which support colors. You can use it in
13855 your shell's ressource file to enable colors for the prompt and commands
13856 if this variable is set.
13859 (service openssh-service-type
13860 (openssh-configuration
13861 (accepted-environment '("COLORTERM"))))
13864 @item @code{authorized-keys} (default: @code{'()})
13865 @cindex authorized keys, SSH
13866 @cindex SSH authorized keys
13867 This is the list of authorized keys. Each element of the list is a user
13868 name followed by one or more file-like objects that represent SSH public
13872 (openssh-configuration
13874 `(("rekado" ,(local-file "rekado.pub"))
13875 ("chris" ,(local-file "chris.pub"))
13876 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13880 registers the specified public keys for user accounts @code{rekado},
13881 @code{chris}, and @code{root}.
13883 Additional authorized keys can be specified @i{via}
13884 @code{service-extension}.
13886 Note that this does @emph{not} interfere with the use of
13887 @file{~/.ssh/authorized_keys}.
13889 @item @code{log-level} (default: @code{'info})
13890 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13891 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13892 page for @file{sshd_config} for the full list of level names.
13894 @item @code{extra-content} (default: @code{""})
13895 This field can be used to append arbitrary text to the configuration file. It
13896 is especially useful for elaborate configurations that cannot be expressed
13897 otherwise. This configuration, for example, would generally disable root
13898 logins, but permit them from one specific IP address:
13901 (openssh-configuration
13903 Match Address 192.168.0.1
13904 PermitRootLogin yes"))
13910 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13911 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13912 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13915 For example, to specify a Dropbear service listening on port 1234, add
13916 this call to the operating system's @code{services} field:
13919 (dropbear-service (dropbear-configuration
13920 (port-number 1234)))
13924 @deftp {Data Type} dropbear-configuration
13925 This data type represents the configuration of a Dropbear SSH daemon.
13928 @item @code{dropbear} (default: @var{dropbear})
13929 The Dropbear package to use.
13931 @item @code{port-number} (default: 22)
13932 The TCP port where the daemon waits for incoming connections.
13934 @item @code{syslog-output?} (default: @code{#t})
13935 Whether to enable syslog output.
13937 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13938 File name of the daemon's PID file.
13940 @item @code{root-login?} (default: @code{#f})
13941 Whether to allow @code{root} logins.
13943 @item @code{allow-empty-passwords?} (default: @code{#f})
13944 Whether to allow empty passwords.
13946 @item @code{password-authentication?} (default: @code{#t})
13947 Whether to enable password-based authentication.
13951 @defvr {Scheme Variable} %facebook-host-aliases
13952 This variable contains a string for use in @file{/etc/hosts}
13953 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13954 line contains a entry that maps a known server name of the Facebook
13955 on-line service---e.g., @code{www.facebook.com}---to the local
13956 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13958 This variable is typically used in the @code{hosts-file} field of an
13959 @code{operating-system} declaration (@pxref{operating-system Reference,
13960 @file{/etc/hosts}}):
13963 (use-modules (gnu) (guix))
13966 (host-name "mymachine")
13969 ;; Create a /etc/hosts file with aliases for "localhost"
13970 ;; and "mymachine", as well as for Facebook servers.
13971 (plain-file "hosts"
13972 (string-append (local-host-aliases host-name)
13973 %facebook-host-aliases))))
13976 This mechanism can prevent programs running locally, such as Web
13977 browsers, from accessing Facebook.
13980 The @code{(gnu services avahi)} provides the following definition.
13982 @defvr {Scheme Variable} avahi-service-type
13983 This is the service that runs @command{avahi-daemon}, a system-wide
13984 mDNS/DNS-SD responder that allows for service discovery and
13985 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
13986 Its value must be a @code{zero-configuration} record---see below.
13988 This service extends the name service cache daemon (nscd) so that it can
13989 resolve @code{.local} host names using
13990 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13991 Service Switch}, for information on host name resolution.
13993 Additionally, add the @var{avahi} package to the system profile so that
13994 commands such as @command{avahi-browse} are directly usable.
13997 @deftp {Data Type} avahi-configuration
13998 Data type representation the configuration for Avahi.
14002 @item @code{host-name} (default: @code{#f})
14003 If different from @code{#f}, use that as the host name to
14004 publish for this machine; otherwise, use the machine's actual host name.
14006 @item @code{publish?} (default: @code{#t})
14007 When true, allow host names and services to be published (broadcast) over the
14010 @item @code{publish-workstation?} (default: @code{#t})
14011 When true, @command{avahi-daemon} publishes the machine's host name and IP
14012 address via mDNS on the local network. To view the host names published on
14013 your local network, you can run:
14016 avahi-browse _workstation._tcp
14019 @item @code{wide-area?} (default: @code{#f})
14020 When true, DNS-SD over unicast DNS is enabled.
14022 @item @code{ipv4?} (default: @code{#t})
14023 @itemx @code{ipv6?} (default: @code{#t})
14024 These fields determine whether to use IPv4/IPv6 sockets.
14026 @item @code{domains-to-browse} (default: @code{'()})
14027 This is a list of domains to browse.
14031 @deffn {Scheme Variable} openvswitch-service-type
14032 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
14033 service, whose value should be an @code{openvswitch-configuration}
14037 @deftp {Data Type} openvswitch-configuration
14038 Data type representing the configuration of Open vSwitch, a multilayer
14039 virtual switch which is designed to enable massive network automation
14040 through programmatic extension.
14043 @item @code{package} (default: @var{openvswitch})
14044 Package object of the Open vSwitch.
14049 @defvr {Scheme Variable} pagekite-service-type
14050 This is the service type for the @uref{https://pagekite.net, PageKite} service,
14051 a tunneling solution for making localhost servers publicly visible, even from
14052 behind NAT or restrictive firewalls. The value for this service type is a
14053 @code{pagekite-configuration} record.
14055 Here's an example exposing the local HTTP and SSH daemons:
14058 (service pagekite-service-type
14059 (pagekite-configuration
14060 (kites '("http:@@kitename:localhost:80:@@kitesecret"
14061 "raw/22:@@kitename:localhost:22:@@kitesecret"))
14062 (extra-file "/etc/pagekite.rc")))
14066 @deftp {Data Type} pagekite-configuration
14067 Data type representing the configuration of PageKite.
14070 @item @code{package} (default: @var{pagekite})
14071 Package object of PageKite.
14073 @item @code{kitename} (default: @code{#f})
14074 PageKite name for authenticating to the frontend server.
14076 @item @code{kitesecret} (default: @code{#f})
14077 Shared secret for authenticating to the frontend server. You should probably
14078 put this inside @code{extra-file} instead.
14080 @item @code{frontend} (default: @code{#f})
14081 Connect to the named PageKite frontend server instead of the
14082 @uref{https://pagekite.net,,pagekite.net} service.
14084 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
14085 List of service kites to use. Exposes HTTP on port 80 by default. The format
14086 is @code{proto:kitename:host:port:secret}.
14088 @item @code{extra-file} (default: @code{#f})
14089 Extra configuration file to read, which you are expected to create manually.
14090 Use this to add additional options and manage shared secrets out-of-band.
14096 @subsection X Window
14099 @cindex X Window System
14100 @cindex login manager
14101 Support for the X Window graphical display system---specifically
14102 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
14103 there is no @code{xorg-service} procedure. Instead, the X server is
14104 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
14107 @cindex GNOME, login manager
14108 GDM of course allows users to log in into window managers and desktop
14109 environments other than GNOME; for those using GNOME, GDM is required for
14110 features such as automatic screen locking.
14112 @cindex window manager
14113 To use X11, you must install at least one @dfn{window manager}---for
14114 example the @code{windowmaker} or @code{openbox} packages---preferably
14115 by adding it to the @code{packages} field of your operating system
14116 definition (@pxref{operating-system Reference, system-wide packages}).
14118 @defvr {Scheme Variable} gdm-service-type
14119 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
14120 Desktop Manager} (GDM), a program that manages graphical display servers and
14121 handles graphical user logins. Its value must be a @code{gdm-configuration}
14124 @cindex session types (X11)
14125 @cindex X11 session types
14126 GDM looks for @dfn{session types} described by the @file{.desktop} files in
14127 @file{/run/current-system/profile/share/xsessions} and allows users to choose
14128 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
14129 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
14130 set of packages automatically makes them available at the log-in screen.
14132 In addition, @file{~/.xsession} files are honored. When available,
14133 @file{~/.xsession} must be an executable that starts a window manager
14134 and/or other X clients.
14137 @deftp {Data Type} gdm-configuration
14139 @item @code{auto-login?} (default: @code{#f})
14140 @itemx @code{default-user} (default: @code{#f})
14141 When @code{auto-login?} is false, GDM presents a log-in screen.
14143 When @code{auto-login?} is true, GDM logs in directly as
14144 @code{default-user}.
14146 @item @code{debug?} (default: @code{#f})
14147 When true, GDM writes debug messages to its log.
14149 @item @code{gnome-shell-assets} (default: ...)
14150 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
14152 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
14153 Configuration of the Xorg graphical server.
14155 @item @code{xsession} (default: @code{(xinitrc)})
14156 Script to run before starting a X session.
14158 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
14159 File name of the @code{dbus-daemon} executable.
14161 @item @code{gdm} (default: @code{gdm})
14162 The GDM package to use.
14166 @defvr {Scheme Variable} slim-service-type
14167 This is the type for the SLiM graphical login manager for X11.
14169 Like GDM, SLiM looks for session types described by @file{.desktop} files and
14170 allows users to choose a session from the log-in screen using @kbd{F1}. It
14171 also honors @file{~/.xsession} files.
14173 Unlike GDM, SLiM does not spawn the user session on a different VT after
14174 logging in, which means that you can only start one graphical session. If you
14175 want to be able to run multiple graphical sessions at the same time you have
14176 to add multiple SLiM services to your system services. The following example
14177 shows how to replace the default GDM service with two SLiM services on tty7
14181 (use-modules (gnu services)
14182 (gnu services desktop)
14183 (gnu services xorg)
14184 (srfi srfi-1)) ;for 'remove'
14188 (services (cons* (service slim-service-type (slim-configuration
14191 (service slim-service-type (slim-configuration
14194 (remove (lambda (service)
14195 (eq? (service-kind service) gdm-service-type))
14196 %desktop-services))))
14201 @deftp {Data Type} slim-configuration
14202 Data type representing the configuration of @code{slim-service-type}.
14205 @item @code{allow-empty-passwords?} (default: @code{#t})
14206 Whether to allow logins with empty passwords.
14208 @item @code{auto-login?} (default: @code{#f})
14209 @itemx @code{default-user} (default: @code{""})
14210 When @code{auto-login?} is false, SLiM presents a log-in screen.
14212 When @code{auto-login?} is true, SLiM logs in directly as
14213 @code{default-user}.
14215 @item @code{theme} (default: @code{%default-slim-theme})
14216 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
14217 The graphical theme to use and its name.
14219 @item @code{auto-login-session} (default: @code{#f})
14220 If true, this must be the name of the executable to start as the default
14221 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
14223 If false, a session described by one of the available @file{.desktop}
14224 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
14228 You must install at least one window manager in the system profile or in
14229 your user profile. Failing to do that, if @code{auto-login-session} is
14230 false, you will be unable to log in.
14233 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14234 Configuration of the Xorg graphical server.
14236 @item @code{display} (default @code{":0"})
14237 The display on which to start the Xorg graphical server.
14239 @item @code{vt} (default @code{"vt7"})
14240 The VT on which to start the Xorg graphical server.
14242 @item @code{xauth} (default: @code{xauth})
14243 The XAuth package to use.
14245 @item @code{shepherd} (default: @code{shepherd})
14246 The Shepherd package used when invoking @command{halt} and
14249 @item @code{sessreg} (default: @code{sessreg})
14250 The sessreg package used in order to register the session.
14252 @item @code{slim} (default: @code{slim})
14253 The SLiM package to use.
14257 @defvr {Scheme Variable} %default-theme
14258 @defvrx {Scheme Variable} %default-theme-name
14259 The default SLiM theme and its name.
14263 @deftp {Data Type} sddm-configuration
14264 This is the data type representing the sddm service configuration.
14267 @item @code{display-server} (default: "x11")
14268 Select display server to use for the greeter. Valid values are "x11"
14271 @item @code{numlock} (default: "on")
14272 Valid values are "on", "off" or "none".
14274 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
14275 Command to run when halting.
14277 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
14278 Command to run when rebooting.
14280 @item @code{theme} (default "maldives")
14281 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
14283 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
14284 Directory to look for themes.
14286 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
14287 Directory to look for faces.
14289 @item @code{default-path} (default "/run/current-system/profile/bin")
14290 Default PATH to use.
14292 @item @code{minimum-uid} (default: 1000)
14293 Minimum UID displayed in SDDM and allowed for log-in.
14295 @item @code{maximum-uid} (default: 2000)
14296 Maximum UID to display in SDDM.
14298 @item @code{remember-last-user?} (default #t)
14299 Remember last user.
14301 @item @code{remember-last-session?} (default #t)
14302 Remember last session.
14304 @item @code{hide-users} (default "")
14305 Usernames to hide from SDDM greeter.
14307 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
14308 Users with shells listed will be hidden from the SDDM greeter.
14310 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
14311 Script to run before starting a wayland session.
14313 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
14314 Directory to look for desktop files starting wayland sessions.
14316 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14317 Configuration of the Xorg graphical server.
14319 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
14322 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
14325 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
14326 Script to run after starting xorg-server.
14328 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
14329 Script to run before stopping xorg-server.
14331 @item @code{xsession-command} (default: @code{xinitrc})
14332 Script to run before starting a X session.
14334 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
14335 Directory to look for desktop files starting X sessions.
14337 @item @code{minimum-vt} (default: 7)
14340 @item @code{auto-login-user} (default "")
14341 User to use for auto-login.
14343 @item @code{auto-login-session} (default "")
14344 Desktop file to use for auto-login.
14346 @item @code{relogin?} (default #f)
14347 Relogin after logout.
14352 @cindex login manager
14354 @defvr {Scheme Variable} sddm-service-type
14355 This is the type of the service to run the
14356 @uref{https://github.com/sddm/sddm,SSDM display manager}. Its value
14357 must be a @code{sddm-configuration} record (see below).
14359 Here's an example use:
14362 (service sddm-service-type
14363 (sddm-configuration
14364 (auto-login-user "alice")
14365 (auto-login-session "xfce.desktop")))
14369 @deftp {Data Type} sddm-configuration
14370 This data type represents the configuration of the SDDM login manager.
14371 The available fields are:
14374 @item @code{sddm} (default: @code{sddm})
14375 The SDDM package to use.
14377 @item @code{display-server} (default: @code{"x11"})
14378 This must be either @code{"x11"} or @code{"wayland"}.
14380 @c FIXME: Add more fields.
14382 @item @code{auto-login-user} (default: @code{""})
14383 If non-empty, this is the user account under which to log in
14386 @item @code{auto-login-session} (default: @code{""})
14387 If non-empty, this is the @file{.desktop} file name to use as the
14388 auto-login session.
14392 @cindex Xorg, configuration
14393 @deftp {Data Type} xorg-configuration
14394 This data type represents the configuration of the Xorg graphical display
14395 server. Note that there is not Xorg service; instead, the X server is started
14396 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
14397 of these display managers aggregates an @code{xorg-configuration} record.
14400 @item @code{modules} (default: @code{%default-xorg-modules})
14401 This is a list of @dfn{module packages} loaded by the Xorg
14402 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
14404 @item @code{fonts} (default: @code{%default-xorg-fonts})
14405 This is a list of font directories to add to the server's @dfn{font path}.
14407 @item @code{drivers} (default: @code{'()})
14408 This must be either the empty list, in which case Xorg chooses a graphics
14409 driver automatically, or a list of driver names that will be tried in this
14410 order---e.g., @code{("modesetting" "vesa")}.
14412 @item @code{resolutions} (default: @code{'()})
14413 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
14414 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
14417 @cindex keyboard layout, for Xorg
14418 @cindex keymap, for Xorg
14419 @item @code{keyboard-layout} (default: @code{#f})
14420 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
14421 English (``qwerty'') for a 105-key PC keyboard.
14423 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
14424 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
14425 information on how to specify the keyboard layout.
14427 @item @code{extra-config} (default: @code{'()})
14428 This is a list of strings or objects appended to the configuration file. It
14429 is used to pass extra text to be added verbatim to the configuration file.
14431 @item @code{server} (default: @code{xorg-server})
14432 This is the package providing the Xorg server.
14434 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
14435 This is the list of command-line arguments to pass to the X server. The
14436 default is @code{-nolisten tcp}.
14440 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
14441 [@var{login-manager-service-type}]
14442 Tell the log-in manager (of type @var{login-manager-service-type}) to use
14443 @var{config}, an @code{<xorg-configuration>} record.
14445 Since the Xorg configuration is embedded in the log-in manager's
14446 configuration---e.g., @code{gdm-configuration}---this procedure provides a
14447 shorthand to set the Xorg configuration.
14450 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
14451 Return a @code{startx} script in which the modules, fonts, etc. specified
14452 in @var{config}, are available. The result should be used in place of
14455 Usually the X server is started by a login manager.
14459 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
14460 Add @var{package}, a package for a screen locker or screen saver whose
14461 command is @var{program}, to the set of setuid programs and add a PAM entry
14462 for it. For example:
14465 (screen-locker-service xlockmore "xlock")
14468 makes the good ol' XlockMore usable.
14472 @node Printing Services
14473 @subsection Printing Services
14475 @cindex printer support with CUPS
14476 The @code{(gnu services cups)} module provides a Guix service definition
14477 for the CUPS printing service. To add printer support to a Guix
14478 system, add a @code{cups-service} to the operating system definition:
14480 @deffn {Scheme Variable} cups-service-type
14481 The service type for the CUPS print server. Its value should be a valid
14482 CUPS configuration (see below). To use the default settings, simply
14485 (service cups-service-type)
14489 The CUPS configuration controls the basic things about your CUPS
14490 installation: what interfaces it listens on, what to do if a print job
14491 fails, how much logging to do, and so on. To actually add a printer,
14492 you have to visit the @url{http://localhost:631} URL, or use a tool such
14493 as GNOME's printer configuration services. By default, configuring a
14494 CUPS service will generate a self-signed certificate if needed, for
14495 secure connections to the print server.
14497 Suppose you want to enable the Web interface of CUPS and also add
14498 support for Epson printers @i{via} the @code{escpr} package and for HP
14499 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
14500 like this (you need to use the @code{(gnu packages cups)} module):
14503 (service cups-service-type
14504 (cups-configuration
14505 (web-interface? #t)
14507 (list cups-filters escpr hplip-minimal))))
14510 Note: If you wish to use the Qt5 based GUI which comes with the hplip
14511 package then it is suggested that you install the @code{hplip} package,
14512 either in your OS configuration file or as your user.
14514 The available configuration parameters follow. Each parameter
14515 definition is preceded by its type; for example, @samp{string-list foo}
14516 indicates that the @code{foo} parameter should be specified as a list of
14517 strings. There is also a way to specify the configuration as a string,
14518 if you have an old @code{cupsd.conf} file that you want to port over
14519 from some other system; see the end for more details.
14521 @c The following documentation was initially generated by
14522 @c (generate-documentation) in (gnu services cups). Manually maintained
14523 @c documentation is better, so we shouldn't hesitate to edit below as
14524 @c needed. However if the change you want to make to this documentation
14525 @c can be done in an automated way, it's probably easier to change
14526 @c (generate-documentation) than to make it below and have to deal with
14527 @c the churn as CUPS updates.
14530 Available @code{cups-configuration} fields are:
14532 @deftypevr {@code{cups-configuration} parameter} package cups
14536 @deftypevr {@code{cups-configuration} parameter} package-list extensions
14537 Drivers and other extensions to the CUPS package.
14540 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
14541 Configuration of where to write logs, what directories to use for print
14542 spools, and related privileged configuration parameters.
14544 Available @code{files-configuration} fields are:
14546 @deftypevr {@code{files-configuration} parameter} log-location access-log
14547 Defines the access log filename. Specifying a blank filename disables
14548 access log generation. The value @code{stderr} causes log entries to be
14549 sent to the standard error file when the scheduler is running in the
14550 foreground, or to the system log daemon when run in the background. The
14551 value @code{syslog} causes log entries to be sent to the system log
14552 daemon. The server name may be included in filenames using the string
14553 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
14555 Defaults to @samp{"/var/log/cups/access_log"}.
14558 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
14559 Where CUPS should cache data.
14561 Defaults to @samp{"/var/cache/cups"}.
14564 @deftypevr {@code{files-configuration} parameter} string config-file-perm
14565 Specifies the permissions for all configuration files that the scheduler
14568 Note that the permissions for the printers.conf file are currently
14569 masked to only allow access from the scheduler user (typically root).
14570 This is done because printer device URIs sometimes contain sensitive
14571 authentication information that should not be generally known on the
14572 system. There is no way to disable this security feature.
14574 Defaults to @samp{"0640"}.
14577 @deftypevr {@code{files-configuration} parameter} log-location error-log
14578 Defines the error log filename. Specifying a blank filename disables
14579 error log generation. The value @code{stderr} causes log entries to be
14580 sent to the standard error file when the scheduler is running in the
14581 foreground, or to the system log daemon when run in the background. The
14582 value @code{syslog} causes log entries to be sent to the system log
14583 daemon. The server name may be included in filenames using the string
14584 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
14586 Defaults to @samp{"/var/log/cups/error_log"}.
14589 @deftypevr {@code{files-configuration} parameter} string fatal-errors
14590 Specifies which errors are fatal, causing the scheduler to exit. The
14595 No errors are fatal.
14598 All of the errors below are fatal.
14601 Browsing initialization errors are fatal, for example failed connections
14602 to the DNS-SD daemon.
14605 Configuration file syntax errors are fatal.
14608 Listen or Port errors are fatal, except for IPv6 failures on the
14609 loopback or @code{any} addresses.
14612 Log file creation or write errors are fatal.
14615 Bad startup file permissions are fatal, for example shared TLS
14616 certificate and key files with world-read permissions.
14619 Defaults to @samp{"all -browse"}.
14622 @deftypevr {@code{files-configuration} parameter} boolean file-device?
14623 Specifies whether the file pseudo-device can be used for new printer
14624 queues. The URI @uref{file:///dev/null} is always allowed.
14626 Defaults to @samp{#f}.
14629 @deftypevr {@code{files-configuration} parameter} string group
14630 Specifies the group name or ID that will be used when executing external
14633 Defaults to @samp{"lp"}.
14636 @deftypevr {@code{files-configuration} parameter} string log-file-perm
14637 Specifies the permissions for all log files that the scheduler writes.
14639 Defaults to @samp{"0644"}.
14642 @deftypevr {@code{files-configuration} parameter} log-location page-log
14643 Defines the page log filename. Specifying a blank filename disables
14644 page log generation. The value @code{stderr} causes log entries to be
14645 sent to the standard error file when the scheduler is running in the
14646 foreground, or to the system log daemon when run in the background. The
14647 value @code{syslog} causes log entries to be sent to the system log
14648 daemon. The server name may be included in filenames using the string
14649 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
14651 Defaults to @samp{"/var/log/cups/page_log"}.
14654 @deftypevr {@code{files-configuration} parameter} string remote-root
14655 Specifies the username that is associated with unauthenticated accesses
14656 by clients claiming to be the root user. The default is @code{remroot}.
14658 Defaults to @samp{"remroot"}.
14661 @deftypevr {@code{files-configuration} parameter} file-name request-root
14662 Specifies the directory that contains print jobs and other HTTP request
14665 Defaults to @samp{"/var/spool/cups"}.
14668 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
14669 Specifies the level of security sandboxing that is applied to print
14670 filters, backends, and other child processes of the scheduler; either
14671 @code{relaxed} or @code{strict}. This directive is currently only
14672 used/supported on macOS.
14674 Defaults to @samp{strict}.
14677 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
14678 Specifies the location of TLS certificates and private keys. CUPS will
14679 look for public and private keys in this directory: a @code{.crt} files
14680 for PEM-encoded certificates and corresponding @code{.key} files for
14681 PEM-encoded private keys.
14683 Defaults to @samp{"/etc/cups/ssl"}.
14686 @deftypevr {@code{files-configuration} parameter} file-name server-root
14687 Specifies the directory containing the server configuration files.
14689 Defaults to @samp{"/etc/cups"}.
14692 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14693 Specifies whether the scheduler calls fsync(2) after writing
14694 configuration or state files.
14696 Defaults to @samp{#f}.
14699 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14700 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14703 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14704 Specifies the directory where temporary files are stored.
14706 Defaults to @samp{"/var/spool/cups/tmp"}.
14709 @deftypevr {@code{files-configuration} parameter} string user
14710 Specifies the user name or ID that is used when running external
14713 Defaults to @samp{"lp"}.
14716 @deftypevr {@code{files-configuration} parameter} string set-env
14717 Set the specified environment variable to be passed to child processes.
14719 Defaults to @samp{"variable value"}.
14723 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14724 Specifies the logging level for the AccessLog file. The @code{config}
14725 level logs when printers and classes are added, deleted, or modified and
14726 when configuration files are accessed or updated. The @code{actions}
14727 level logs when print jobs are submitted, held, released, modified, or
14728 canceled, and any of the conditions for @code{config}. The @code{all}
14729 level logs all requests.
14731 Defaults to @samp{actions}.
14734 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14735 Specifies whether to purge job history data automatically when it is no
14736 longer required for quotas.
14738 Defaults to @samp{#f}.
14741 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
14742 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
14743 For example, @samp{"_cups" "_print"} will tell network clients that both
14744 CUPS sharing and IPP Everywhere are supported.
14746 Defaults to @samp{"_cups"}.
14749 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14750 Specifies which protocols to use for local printer sharing.
14752 Defaults to @samp{dnssd}.
14755 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14756 Specifies whether the CUPS web interface is advertised.
14758 Defaults to @samp{#f}.
14761 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14762 Specifies whether shared printers are advertised.
14764 Defaults to @samp{#f}.
14767 @deftypevr {@code{cups-configuration} parameter} string classification
14768 Specifies the security classification of the server. Any valid banner
14769 name can be used, including "classified", "confidential", "secret",
14770 "topsecret", and "unclassified", or the banner can be omitted to disable
14771 secure printing functions.
14773 Defaults to @samp{""}.
14776 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14777 Specifies whether users may override the classification (cover page) of
14778 individual print jobs using the @code{job-sheets} option.
14780 Defaults to @samp{#f}.
14783 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14784 Specifies the default type of authentication to use.
14786 Defaults to @samp{Basic}.
14789 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14790 Specifies whether encryption will be used for authenticated requests.
14792 Defaults to @samp{Required}.
14795 @deftypevr {@code{cups-configuration} parameter} string default-language
14796 Specifies the default language to use for text and web content.
14798 Defaults to @samp{"en"}.
14801 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14802 Specifies the default paper size for new print queues. @samp{"Auto"}
14803 uses a locale-specific default, while @samp{"None"} specifies there is
14804 no default paper size. Specific size names are typically
14805 @samp{"Letter"} or @samp{"A4"}.
14807 Defaults to @samp{"Auto"}.
14810 @deftypevr {@code{cups-configuration} parameter} string default-policy
14811 Specifies the default access policy to use.
14813 Defaults to @samp{"default"}.
14816 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14817 Specifies whether local printers are shared by default.
14819 Defaults to @samp{#t}.
14822 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14823 Specifies the delay for updating of configuration and state files, in
14824 seconds. A value of 0 causes the update to happen as soon as possible,
14825 typically within a few milliseconds.
14827 Defaults to @samp{30}.
14830 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14831 Specifies what to do when an error occurs. Possible values are
14832 @code{abort-job}, which will discard the failed print job;
14833 @code{retry-job}, which will retry the job at a later time;
14834 @code{retry-current-job}, which retries the failed job immediately; and
14835 @code{stop-printer}, which stops the printer.
14837 Defaults to @samp{stop-printer}.
14840 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14841 Specifies the maximum cost of filters that are run concurrently, which
14842 can be used to minimize disk, memory, and CPU resource problems. A
14843 limit of 0 disables filter limiting. An average print to a
14844 non-PostScript printer needs a filter limit of about 200. A PostScript
14845 printer needs about half that (100). Setting the limit below these
14846 thresholds will effectively limit the scheduler to printing a single job
14849 Defaults to @samp{0}.
14852 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14853 Specifies the scheduling priority of filters that are run to print a
14854 job. The nice value ranges from 0, the highest priority, to 19, the
14857 Defaults to @samp{0}.
14860 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14861 Specifies whether to do reverse lookups on connecting clients. The
14862 @code{double} setting causes @code{cupsd} to verify that the hostname
14863 resolved from the address matches one of the addresses returned for that
14864 hostname. Double lookups also prevent clients with unregistered
14865 addresses from connecting to your server. Only set this option to
14866 @code{#t} or @code{double} if absolutely required.
14868 Defaults to @samp{#f}.
14871 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14872 Specifies the number of seconds to wait before killing the filters and
14873 backend associated with a canceled or held job.
14875 Defaults to @samp{30}.
14878 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14879 Specifies the interval between retries of jobs in seconds. This is
14880 typically used for fax queues but can also be used with normal print
14881 queues whose error policy is @code{retry-job} or
14882 @code{retry-current-job}.
14884 Defaults to @samp{30}.
14887 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14888 Specifies the number of retries that are done for jobs. This is
14889 typically used for fax queues but can also be used with normal print
14890 queues whose error policy is @code{retry-job} or
14891 @code{retry-current-job}.
14893 Defaults to @samp{5}.
14896 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14897 Specifies whether to support HTTP keep-alive connections.
14899 Defaults to @samp{#t}.
14902 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14903 Specifies how long an idle client connection remains open, in seconds.
14905 Defaults to @samp{30}.
14908 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14909 Specifies the maximum size of print files, IPP requests, and HTML form
14910 data. A limit of 0 disables the limit check.
14912 Defaults to @samp{0}.
14915 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14916 Listens on the specified interfaces for connections. Valid values are
14917 of the form @var{address}:@var{port}, where @var{address} is either an
14918 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14919 indicate all addresses. Values can also be file names of local UNIX
14920 domain sockets. The Listen directive is similar to the Port directive
14921 but allows you to restrict access to specific interfaces or networks.
14924 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14925 Specifies the number of pending connections that will be allowed. This
14926 normally only affects very busy servers that have reached the MaxClients
14927 limit, but can also be triggered by large numbers of simultaneous
14928 connections. When the limit is reached, the operating system will
14929 refuse additional connections until the scheduler can accept the pending
14932 Defaults to @samp{128}.
14935 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14936 Specifies a set of additional access controls.
14938 Available @code{location-access-controls} fields are:
14940 @deftypevr {@code{location-access-controls} parameter} file-name path
14941 Specifies the URI path to which the access control applies.
14944 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14945 Access controls for all access to this path, in the same format as the
14946 @code{access-controls} of @code{operation-access-control}.
14948 Defaults to @samp{()}.
14951 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14952 Access controls for method-specific access to this path.
14954 Defaults to @samp{()}.
14956 Available @code{method-access-controls} fields are:
14958 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14959 If @code{#t}, apply access controls to all methods except the listed
14960 methods. Otherwise apply to only the listed methods.
14962 Defaults to @samp{#f}.
14965 @deftypevr {@code{method-access-controls} parameter} method-list methods
14966 Methods to which this access control applies.
14968 Defaults to @samp{()}.
14971 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14972 Access control directives, as a list of strings. Each string should be
14973 one directive, such as "Order allow,deny".
14975 Defaults to @samp{()}.
14980 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14981 Specifies the number of debugging messages that are retained for logging
14982 if an error occurs in a print job. Debug messages are logged regardless
14983 of the LogLevel setting.
14985 Defaults to @samp{100}.
14988 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14989 Specifies the level of logging for the ErrorLog file. The value
14990 @code{none} stops all logging while @code{debug2} logs everything.
14992 Defaults to @samp{info}.
14995 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14996 Specifies the format of the date and time in the log files. The value
14997 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14999 Defaults to @samp{standard}.
15002 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
15003 Specifies the maximum number of simultaneous clients that are allowed by
15006 Defaults to @samp{100}.
15009 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
15010 Specifies the maximum number of simultaneous clients that are allowed
15011 from a single address.
15013 Defaults to @samp{100}.
15016 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
15017 Specifies the maximum number of copies that a user can print of each
15020 Defaults to @samp{9999}.
15023 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
15024 Specifies the maximum time a job may remain in the @code{indefinite}
15025 hold state before it is canceled. A value of 0 disables cancellation of
15028 Defaults to @samp{0}.
15031 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
15032 Specifies the maximum number of simultaneous jobs that are allowed. Set
15033 to 0 to allow an unlimited number of jobs.
15035 Defaults to @samp{500}.
15038 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
15039 Specifies the maximum number of simultaneous jobs that are allowed per
15040 printer. A value of 0 allows up to MaxJobs jobs per printer.
15042 Defaults to @samp{0}.
15045 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
15046 Specifies the maximum number of simultaneous jobs that are allowed per
15047 user. A value of 0 allows up to MaxJobs jobs per user.
15049 Defaults to @samp{0}.
15052 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
15053 Specifies the maximum time a job may take to print before it is
15054 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
15056 Defaults to @samp{10800}.
15059 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
15060 Specifies the maximum size of the log files before they are rotated, in
15061 bytes. The value 0 disables log rotation.
15063 Defaults to @samp{1048576}.
15066 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
15067 Specifies the maximum amount of time to allow between files in a
15068 multiple file print job, in seconds.
15070 Defaults to @samp{300}.
15073 @deftypevr {@code{cups-configuration} parameter} string page-log-format
15074 Specifies the format of PageLog lines. Sequences beginning with percent
15075 (@samp{%}) characters are replaced with the corresponding information,
15076 while all other characters are copied literally. The following percent
15077 sequences are recognized:
15081 insert a single percent character
15084 insert the value of the specified IPP attribute
15087 insert the number of copies for the current page
15090 insert the current page number
15093 insert the current date and time in common log format
15099 insert the printer name
15102 insert the username
15105 A value of the empty string disables page logging. The string @code{%p
15106 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
15107 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
15110 Defaults to @samp{""}.
15113 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
15114 Passes the specified environment variable(s) to child processes; a list
15117 Defaults to @samp{()}.
15120 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
15121 Specifies named access control policies.
15123 Available @code{policy-configuration} fields are:
15125 @deftypevr {@code{policy-configuration} parameter} string name
15126 Name of the policy.
15129 @deftypevr {@code{policy-configuration} parameter} string job-private-access
15130 Specifies an access list for a job's private values. @code{@@ACL} maps
15131 to the printer's requesting-user-name-allowed or
15132 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15133 owner. @code{@@SYSTEM} maps to the groups listed for the
15134 @code{system-group} field of the @code{files-config} configuration,
15135 which is reified into the @code{cups-files.conf(5)} file. Other
15136 possible elements of the access list include specific user names, and
15137 @code{@@@var{group}} to indicate members of a specific group. The
15138 access list may also be simply @code{all} or @code{default}.
15140 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15143 @deftypevr {@code{policy-configuration} parameter} string job-private-values
15144 Specifies the list of job values to make private, or @code{all},
15145 @code{default}, or @code{none}.
15147 Defaults to @samp{"job-name job-originating-host-name
15148 job-originating-user-name phone"}.
15151 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
15152 Specifies an access list for a subscription's private values.
15153 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
15154 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15155 owner. @code{@@SYSTEM} maps to the groups listed for the
15156 @code{system-group} field of the @code{files-config} configuration,
15157 which is reified into the @code{cups-files.conf(5)} file. Other
15158 possible elements of the access list include specific user names, and
15159 @code{@@@var{group}} to indicate members of a specific group. The
15160 access list may also be simply @code{all} or @code{default}.
15162 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15165 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
15166 Specifies the list of job values to make private, or @code{all},
15167 @code{default}, or @code{none}.
15169 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
15170 notify-subscriber-user-name notify-user-data"}.
15173 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
15174 Access control by IPP operation.
15176 Defaults to @samp{()}.
15180 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
15181 Specifies whether job files (documents) are preserved after a job is
15182 printed. If a numeric value is specified, job files are preserved for
15183 the indicated number of seconds after printing. Otherwise a boolean
15184 value applies indefinitely.
15186 Defaults to @samp{86400}.
15189 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
15190 Specifies whether the job history is preserved after a job is printed.
15191 If a numeric value is specified, the job history is preserved for the
15192 indicated number of seconds after printing. If @code{#t}, the job
15193 history is preserved until the MaxJobs limit is reached.
15195 Defaults to @samp{#t}.
15198 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
15199 Specifies the amount of time to wait for job completion before
15200 restarting the scheduler.
15202 Defaults to @samp{30}.
15205 @deftypevr {@code{cups-configuration} parameter} string rip-cache
15206 Specifies the maximum amount of memory to use when converting documents
15207 into bitmaps for a printer.
15209 Defaults to @samp{"128m"}.
15212 @deftypevr {@code{cups-configuration} parameter} string server-admin
15213 Specifies the email address of the server administrator.
15215 Defaults to @samp{"root@@localhost.localdomain"}.
15218 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
15219 The ServerAlias directive is used for HTTP Host header validation when
15220 clients connect to the scheduler from external interfaces. Using the
15221 special name @code{*} can expose your system to known browser-based DNS
15222 rebinding attacks, even when accessing sites through a firewall. If the
15223 auto-discovery of alternate names does not work, we recommend listing
15224 each alternate name with a ServerAlias directive instead of using
15227 Defaults to @samp{*}.
15230 @deftypevr {@code{cups-configuration} parameter} string server-name
15231 Specifies the fully-qualified host name of the server.
15233 Defaults to @samp{"localhost"}.
15236 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
15237 Specifies what information is included in the Server header of HTTP
15238 responses. @code{None} disables the Server header. @code{ProductOnly}
15239 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
15240 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
15241 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
15242 the output of the @code{uname} command. @code{Full} reports @code{CUPS
15243 2.0.0 (@var{uname}) IPP/2.0}.
15245 Defaults to @samp{Minimal}.
15248 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
15249 Listens on the specified interfaces for encrypted connections. Valid
15250 values are of the form @var{address}:@var{port}, where @var{address} is
15251 either an IPv6 address enclosed in brackets, an IPv4 address, or
15252 @code{*} to indicate all addresses.
15254 Defaults to @samp{()}.
15257 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
15258 Sets encryption options. By default, CUPS only supports encryption
15259 using TLS v1.0 or higher using known secure cipher suites. Security is
15260 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
15261 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
15262 suites, which are required for some older clients. The @code{AllowSSL3} option
15263 enables SSL v3.0, which is required for some older clients that do not support
15264 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
15265 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
15266 protocol version to TLS v1.1.
15268 Defaults to @samp{()}.
15271 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
15272 Specifies whether the scheduler requires clients to strictly adhere to
15273 the IPP specifications.
15275 Defaults to @samp{#f}.
15278 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
15279 Specifies the HTTP request timeout, in seconds.
15281 Defaults to @samp{300}.
15285 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
15286 Specifies whether the web interface is enabled.
15288 Defaults to @samp{#f}.
15291 At this point you're probably thinking ``oh dear, Guix manual, I like
15292 you but you can stop already with the configuration options''. Indeed.
15293 However, one more point: it could be that you have an existing
15294 @code{cupsd.conf} that you want to use. In that case, you can pass an
15295 @code{opaque-cups-configuration} as the configuration of a
15296 @code{cups-service-type}.
15298 Available @code{opaque-cups-configuration} fields are:
15300 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
15304 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
15305 The contents of the @code{cupsd.conf}, as a string.
15308 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
15309 The contents of the @code{cups-files.conf} file, as a string.
15312 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
15313 strings of the same name, you could instantiate a CUPS service like
15317 (service cups-service-type
15318 (opaque-cups-configuration
15319 (cupsd.conf cupsd.conf)
15320 (cups-files.conf cups-files.conf)))
15324 @node Desktop Services
15325 @subsection Desktop Services
15327 The @code{(gnu services desktop)} module provides services that are
15328 usually useful in the context of a ``desktop'' setup---that is, on a
15329 machine running a graphical display server, possibly with graphical user
15330 interfaces, etc. It also defines services that provide specific desktop
15331 environments like GNOME, Xfce or MATE.
15333 To simplify things, the module defines a variable containing the set of
15334 services that users typically expect on a machine with a graphical
15335 environment and networking:
15337 @defvr {Scheme Variable} %desktop-services
15338 This is a list of services that builds upon @code{%base-services} and
15339 adds or adjusts services for a typical ``desktop'' setup.
15341 In particular, it adds a graphical login manager (@pxref{X Window,
15342 @code{gdm-service-type}}), screen lockers, a network management tool
15343 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
15344 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
15345 energy and color management services, the @code{elogind} login and seat
15346 manager, the Polkit privilege service, the GeoClue location service, the
15347 AccountsService daemon that allows authorized users change system passwords,
15348 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
15349 name service switch service configured to be able to use @code{nss-mdns}
15350 (@pxref{Name Service Switch, mDNS}).
15353 The @code{%desktop-services} variable can be used as the @code{services}
15354 field of an @code{operating-system} declaration (@pxref{operating-system
15355 Reference, @code{services}}).
15357 Additionally, the @code{gnome-desktop-service-type},
15358 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
15359 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
15360 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
15361 services like the backlight adjustment helpers and the power management
15362 utilities are added to the system, extending @code{polkit} and @code{dbus}
15363 appropriately, allowing GNOME to operate with elevated privileges on a
15364 limited number of special-purpose system interfaces. Additionally,
15365 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
15366 metapackage to the system profile. Likewise, adding the Xfce service
15367 not only adds the @code{xfce} metapackage to the system profile, but it
15368 also gives the Thunar file manager the ability to open a ``root-mode''
15369 file management window, if the user authenticates using the
15370 administrator's password via the standard polkit graphical interface.
15371 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
15372 appropriately, allowing MATE to operate with elevated privileges on a
15373 limited number of special-purpose system interfaces. Additionally,
15374 adding a service of type @code{mate-desktop-service-type} adds the MATE
15375 metapackage to the system profile. ``Adding Enlightenment'' means that
15376 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
15377 are set as setuid, allowing Enlightenment's screen locker and other
15378 functionality to work as expetected.
15380 The desktop environments in Guix use the Xorg display server by
15381 default. If you'd like to use the newer display server protocol
15382 called Wayland, you need to use the @code{sddm-service} instead of
15383 GDM as the graphical login manager. You should then
15384 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
15385 also try starting GNOME on Wayland manually from a TTY with the
15386 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
15387 gnome-session``. Currently only GNOME has support for Wayland.
15389 @defvr {Scheme Variable} gnome-desktop-service-type
15390 This is the type of the service that adds the @uref{https://www.gnome.org,
15391 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
15392 object (see below.)
15394 This service adds the @code{gnome} package to the system profile, and extends
15395 polkit with the actions from @code{gnome-settings-daemon}.
15398 @deftp {Data Type} gnome-desktop-configuration
15399 Configuration record for the GNOME desktop environment.
15402 @item @code{gnome} (default: @code{gnome})
15403 The GNOME package to use.
15407 @defvr {Scheme Variable} xfce-desktop-service-type
15408 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
15409 desktop environment. Its value is an @code{xfce-desktop-configuration} object
15412 This service adds the @code{xfce} package to the system profile, and
15413 extends polkit with the ability for @code{thunar} to manipulate the file
15414 system as root from within a user session, after the user has authenticated
15415 with the administrator's password.
15418 @deftp {Data Type} xfce-desktop-configuration
15419 Configuration record for the Xfce desktop environment.
15422 @item @code{xfce} (default: @code{xfce})
15423 The Xfce package to use.
15427 @deffn {Scheme Variable} mate-desktop-service-type
15428 This is the type of the service that runs the @uref{https://mate-desktop.org/,
15429 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
15430 object (see below.)
15432 This service adds the @code{mate} package to the system
15433 profile, and extends polkit with the actions from
15434 @code{mate-settings-daemon}.
15437 @deftp {Data Type} mate-desktop-configuration
15438 Configuration record for the MATE desktop environment.
15441 @item @code{mate} (default: @code{mate})
15442 The MATE package to use.
15446 @deffn {Scheme Variable} enlightenment-desktop-service-type
15447 Return a service that adds the @code{enlightenment} package to the system
15448 profile, and extends dbus with actions from @code{efl}.
15451 @deftp {Data Type} enlightenment-desktop-service-configuration
15453 @item @code{enlightenment} (default: @code{enlightenment})
15454 The enlightenment package to use.
15458 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
15459 the default @code{%desktop-services} variable doesn't include any of
15460 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
15461 @code{%desktop-services} in the @code{services} field of your
15462 @code{operating-system}:
15465 (use-modules (gnu))
15466 (use-service-modules desktop)
15469 ;; cons* adds items to the list given as its last argument.
15470 (services (cons* (service gnome-desktop-service-type)
15471 (service xfce-desktop-service)
15472 %desktop-services))
15476 These desktop environments will then be available as options in the
15477 graphical login window.
15479 The actual service definitions included in @code{%desktop-services} and
15480 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
15481 are described below.
15483 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
15484 Return a service that runs the ``system bus'', using @var{dbus}, with
15485 support for @var{services}.
15487 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
15488 facility. Its system bus is used to allow system services to communicate
15489 and to be notified of system-wide events.
15491 @var{services} must be a list of packages that provide an
15492 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
15493 and policy files. For example, to allow avahi-daemon to use the system bus,
15494 @var{services} must be equal to @code{(list avahi)}.
15497 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
15498 Return a service that runs the @code{elogind} login and
15499 seat management daemon. @uref{https://github.com/elogind/elogind,
15500 Elogind} exposes a D-Bus interface that can be used to know which users
15501 are logged in, know what kind of sessions they have open, suspend the
15502 system, inhibit system suspend, reboot the system, and other tasks.
15504 Elogind handles most system-level power events for a computer, for
15505 example suspending the system when a lid is closed, or shutting it down
15506 when the power button is pressed.
15508 The @var{config} keyword argument specifies the configuration for
15509 elogind, and should be the result of an @code{(elogind-configuration
15510 (@var{parameter} @var{value})...)} invocation. Available parameters and
15511 their default values are:
15514 @item kill-user-processes?
15516 @item kill-only-users
15518 @item kill-exclude-users
15520 @item inhibit-delay-max-seconds
15522 @item handle-power-key
15524 @item handle-suspend-key
15526 @item handle-hibernate-key
15528 @item handle-lid-switch
15530 @item handle-lid-switch-docked
15532 @item power-key-ignore-inhibited?
15534 @item suspend-key-ignore-inhibited?
15536 @item hibernate-key-ignore-inhibited?
15538 @item lid-switch-ignore-inhibited?
15540 @item holdoff-timeout-seconds
15544 @item idle-action-seconds
15546 @item runtime-directory-size-percent
15548 @item runtime-directory-size
15552 @item suspend-state
15553 @code{("mem" "standby" "freeze")}
15556 @item hibernate-state
15558 @item hibernate-mode
15559 @code{("platform" "shutdown")}
15560 @item hybrid-sleep-state
15562 @item hybrid-sleep-mode
15563 @code{("suspend" "platform" "shutdown")}
15567 @deffn {Scheme Procedure} accountsservice-service @
15568 [#:accountsservice @var{accountsservice}]
15569 Return a service that runs AccountsService, a system service that can
15570 list available accounts, change their passwords, and so on.
15571 AccountsService integrates with PolicyKit to enable unprivileged users
15572 to acquire the capability to modify their system configuration.
15573 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
15574 accountsservice web site} for more information.
15576 The @var{accountsservice} keyword argument is the @code{accountsservice}
15577 package to expose as a service.
15580 @deffn {Scheme Procedure} polkit-service @
15581 [#:polkit @var{polkit}]
15582 Return a service that runs the
15583 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
15584 management service}, which allows system administrators to grant access to
15585 privileged operations in a structured way. By querying the Polkit service, a
15586 privileged system component can know when it should grant additional
15587 capabilities to ordinary users. For example, an ordinary user can be granted
15588 the capability to suspend the system if the user is logged in locally.
15591 @defvr {Scheme Variable} upower-service-type
15592 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
15593 system-wide monitor for power consumption and battery levels, with the given
15594 configuration settings.
15596 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
15597 notably used by GNOME.
15600 @deftp {Data Type} upower-configuration
15601 Data type representation the configuration for UPower.
15605 @item @code{upower} (default: @var{upower})
15606 Package to use for @code{upower}.
15608 @item @code{watts-up-pro?} (default: @code{#f})
15609 Enable the Watts Up Pro device.
15611 @item @code{poll-batteries?} (default: @code{#t})
15612 Enable polling the kernel for battery level changes.
15614 @item @code{ignore-lid?} (default: @code{#f})
15615 Ignore the lid state, this can be useful if it's incorrect on a device.
15617 @item @code{use-percentage-for-policy?} (default: @code{#f})
15618 Whether battery percentage based policy should be used. The default is to use
15619 the time left, change to @code{#t} to use the percentage.
15621 @item @code{percentage-low} (default: @code{10})
15622 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15623 at which the battery is considered low.
15625 @item @code{percentage-critical} (default: @code{3})
15626 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15627 at which the battery is considered critical.
15629 @item @code{percentage-action} (default: @code{2})
15630 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15631 at which action will be taken.
15633 @item @code{time-low} (default: @code{1200})
15634 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15635 seconds at which the battery is considered low.
15637 @item @code{time-critical} (default: @code{300})
15638 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15639 seconds at which the battery is considered critical.
15641 @item @code{time-action} (default: @code{120})
15642 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15643 seconds at which action will be taken.
15645 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
15646 The action taken when @code{percentage-action} or @code{time-action} is
15647 reached (depending on the configuration of @code{use-percentage-for-policy?}).
15649 Possible values are:
15659 @code{'hybrid-sleep}.
15665 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
15666 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
15667 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
15668 notifications and ways to mount/unmount disks. Programs that talk to UDisks
15669 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
15672 @deffn {Scheme Variable} colord-service-type
15673 This is the type of the service that runs @command{colord}, a system
15674 service with a D-Bus
15675 interface to manage the color profiles of input and output devices such as
15676 screens and scanners. It is notably used by the GNOME Color Manager graphical
15677 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
15678 site} for more information.
15681 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
15682 Return a configuration allowing an application to access GeoClue
15683 location data. @var{name} is the Desktop ID of the application, without
15684 the @code{.desktop} part. If @var{allowed?} is true, the application
15685 will have access to location information by default. The boolean
15686 @var{system?} value indicates whether an application is a system component
15687 or not. Finally @var{users} is a list of UIDs of all users for which
15688 this application is allowed location info access. An empty users list
15689 means that all users are allowed.
15692 @defvr {Scheme Variable} %standard-geoclue-applications
15693 The standard list of well-known GeoClue application configurations,
15694 granting authority to the GNOME date-and-time utility to ask for the
15695 current location in order to set the time zone, and allowing the
15696 IceCat and Epiphany web browsers to request location information.
15697 IceCat and Epiphany both query the user before allowing a web page to
15698 know the user's location.
15701 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
15702 [#:whitelist '()] @
15703 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
15704 [#:submit-data? #f]
15705 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15706 [#:submission-nick "geoclue"] @
15707 [#:applications %standard-geoclue-applications]
15708 Return a service that runs the GeoClue location service. This service
15709 provides a D-Bus interface to allow applications to request access to a
15710 user's physical location, and optionally to add information to online
15711 location databases. See
15712 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
15713 web site} for more information.
15716 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
15717 [@w{#:auto-enable? #f}]
15718 Return a service that runs the @command{bluetoothd} daemon, which
15719 manages all the Bluetooth devices and provides a number of D-Bus
15720 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15721 powered automatically at boot, which can be useful when using a
15722 bluetooth keyboard or mouse.
15724 Users need to be in the @code{lp} group to access the D-Bus service.
15727 @node Sound Services
15728 @subsection Sound Services
15730 @cindex sound support
15732 @cindex PulseAudio, sound support
15734 The @code{(gnu services sound)} module provides a service to configure the
15735 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15736 preferred ALSA output driver.
15738 @deffn {Scheme Variable} alsa-service-type
15739 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15740 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15741 configuration file. The value for this type is a @command{alsa-configuration}
15742 record as in this example:
15745 (service alsa-service-type)
15748 See below for details about @code{alsa-configuration}.
15751 @deftp {Data Type} alsa-configuration
15752 Data type representing the configuration for @code{alsa-service}.
15755 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15756 @code{alsa-plugins} package to use.
15758 @item @code{pulseaudio?} (default: @var{#t})
15759 Whether ALSA applications should transparently be made to use the
15760 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15762 Using PulseAudio allows you to run several sound-producing applications
15763 at the same time and to individual control them @i{via}
15764 @command{pavucontrol}, among other things.
15766 @item @code{extra-options} (default: @var{""})
15767 String to append to the @file{/etc/asound.conf} file.
15772 Individual users who want to override the system configuration of ALSA can do
15773 it with the @file{~/.asoundrc} file:
15776 # In guix, we have to specify the absolute path for plugins.
15778 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15781 # Routing ALSA to jack:
15782 # <http://jackaudio.org/faq/routing_alsa.html>.
15786 0 system:playback_1
15787 1 system:playback_2
15804 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15808 @node Database Services
15809 @subsection Database Services
15813 The @code{(gnu services databases)} module provides the following services.
15815 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15816 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15817 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15818 Return a service that runs @var{postgresql}, the PostgreSQL database
15821 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15822 creates a database cluster with @var{locale} as the default
15823 locale, stored in @var{data-directory}. It then listens on @var{port}.
15825 @cindex postgresql extension-packages
15826 Additional extensions are loaded from packages listed in
15827 @var{extension-packages}. Extensions are available at runtime. For instance,
15828 to create a geographic database using the @code{postgis} extension, a user can
15829 configure the postgresql-service as in this example:
15833 (use-package-modules databases geo)
15837 ;; postgresql is required to run `psql' but postgis is not required for
15838 ;; proper operation.
15839 (packages (cons* postgresql %base-packages))
15842 (postgresql-service #:extension-packages (list postgis))
15846 Then the extension becomes visible and you can initialise an empty geographic
15847 database in this way:
15851 > create database postgistest;
15852 > \connect postgistest;
15853 > create extension postgis;
15854 > create extension postgis_topology;
15857 There is no need to add this field for contrib extensions such as hstore or
15858 dblink as they are already loadable by postgresql. This field is only
15859 required to add extensions provided by other packages.
15862 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15863 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15866 The optional @var{config} argument specifies the configuration for
15867 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15870 @deftp {Data Type} mysql-configuration
15871 Data type representing the configuration of @var{mysql-service}.
15874 @item @code{mysql} (default: @var{mariadb})
15875 Package object of the MySQL database server, can be either @var{mariadb}
15878 For MySQL, a temporary root password will be displayed at activation time.
15879 For MariaDB, the root password is empty.
15881 @item @code{port} (default: @code{3306})
15882 TCP port on which the database server listens for incoming connections.
15886 @defvr {Scheme Variable} memcached-service-type
15887 This is the service type for the @uref{https://memcached.org/,
15888 Memcached} service, which provides a distributed in memory cache. The
15889 value for the service type is a @code{memcached-configuration} object.
15893 (service memcached-service-type)
15896 @deftp {Data Type} memcached-configuration
15897 Data type representing the configuration of memcached.
15900 @item @code{memcached} (default: @code{memcached})
15901 The Memcached package to use.
15903 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15904 Network interfaces on which to listen.
15906 @item @code{tcp-port} (default: @code{11211})
15907 Port on which to accept connections on,
15909 @item @code{udp-port} (default: @code{11211})
15910 Port on which to accept UDP connections on, a value of 0 will disable
15911 listening on a UDP socket.
15913 @item @code{additional-options} (default: @code{'()})
15914 Additional command line options to pass to @code{memcached}.
15918 @defvr {Scheme Variable} mongodb-service-type
15919 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15920 The value for the service type is a @code{mongodb-configuration} object.
15924 (service mongodb-service-type)
15927 @deftp {Data Type} mongodb-configuration
15928 Data type representing the configuration of mongodb.
15931 @item @code{mongodb} (default: @code{mongodb})
15932 The MongoDB package to use.
15934 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15935 The configuration file for MongoDB.
15937 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15938 This value is used to create the directory, so that it exists and is
15939 owned by the mongodb user. It should match the data-directory which
15940 MongoDB is configured to use through the configuration file.
15944 @defvr {Scheme Variable} redis-service-type
15945 This is the service type for the @uref{https://redis.io/, Redis}
15946 key/value store, whose value is a @code{redis-configuration} object.
15949 @deftp {Data Type} redis-configuration
15950 Data type representing the configuration of redis.
15953 @item @code{redis} (default: @code{redis})
15954 The Redis package to use.
15956 @item @code{bind} (default: @code{"127.0.0.1"})
15957 Network interface on which to listen.
15959 @item @code{port} (default: @code{6379})
15960 Port on which to accept connections on, a value of 0 will disable
15961 listening on a TCP socket.
15963 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15964 Directory in which to store the database and related files.
15968 @node Mail Services
15969 @subsection Mail Services
15973 The @code{(gnu services mail)} module provides Guix service definitions
15974 for email services: IMAP, POP3, and LMTP servers, as well as mail
15975 transport agents (MTAs). Lots of acronyms! These services are detailed
15976 in the subsections below.
15978 @subsubheading Dovecot Service
15980 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15981 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15984 By default, Dovecot does not need much configuration; the default
15985 configuration object created by @code{(dovecot-configuration)} will
15986 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15987 certificate will be generated for TLS-protected connections, though
15988 Dovecot will also listen on cleartext ports by default. There are a
15989 number of options, though, which mail administrators might need to change,
15990 and as is the case with other services, Guix allows the system
15991 administrator to specify these parameters via a uniform Scheme interface.
15993 For example, to specify that mail is located at @code{maildir~/.mail},
15994 one would instantiate the Dovecot service like this:
15997 (dovecot-service #:config
15998 (dovecot-configuration
15999 (mail-location "maildir:~/.mail")))
16002 The available configuration parameters follow. Each parameter
16003 definition is preceded by its type; for example, @samp{string-list foo}
16004 indicates that the @code{foo} parameter should be specified as a list of
16005 strings. There is also a way to specify the configuration as a string,
16006 if you have an old @code{dovecot.conf} file that you want to port over
16007 from some other system; see the end for more details.
16009 @c The following documentation was initially generated by
16010 @c (generate-documentation) in (gnu services mail). Manually maintained
16011 @c documentation is better, so we shouldn't hesitate to edit below as
16012 @c needed. However if the change you want to make to this documentation
16013 @c can be done in an automated way, it's probably easier to change
16014 @c (generate-documentation) than to make it below and have to deal with
16015 @c the churn as dovecot updates.
16017 Available @code{dovecot-configuration} fields are:
16019 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
16020 The dovecot package.
16023 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
16024 A list of IPs or hosts where to listen for connections. @samp{*}
16025 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
16026 interfaces. If you want to specify non-default ports or anything more
16027 complex, customize the address and port fields of the
16028 @samp{inet-listener} of the specific services you are interested in.
16031 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
16032 List of protocols we want to serve. Available protocols include
16033 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
16035 Available @code{protocol-configuration} fields are:
16037 @deftypevr {@code{protocol-configuration} parameter} string name
16038 The name of the protocol.
16041 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
16042 UNIX socket path to the master authentication server to find users.
16043 This is used by imap (for shared users) and lda.
16044 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16047 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
16048 Space separated list of plugins to load.
16051 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
16052 Maximum number of IMAP connections allowed for a user from each IP
16053 address. NOTE: The username is compared case-sensitively.
16054 Defaults to @samp{10}.
16059 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
16060 List of services to enable. Available services include @samp{imap},
16061 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
16064 Available @code{service-configuration} fields are:
16066 @deftypevr {@code{service-configuration} parameter} string kind
16067 The service kind. Valid values include @code{director},
16068 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
16069 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
16070 @code{tcpwrap}, @code{quota-warning}, or anything else.
16073 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
16074 Listeners for the service. A listener is either a
16075 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
16076 an @code{inet-listener-configuration}.
16077 Defaults to @samp{()}.
16079 Available @code{unix-listener-configuration} fields are:
16081 @deftypevr {@code{unix-listener-configuration} parameter} string path
16082 Path to the file, relative to @code{base-dir} field. This is also used as
16086 @deftypevr {@code{unix-listener-configuration} parameter} string mode
16087 The access mode for the socket.
16088 Defaults to @samp{"0600"}.
16091 @deftypevr {@code{unix-listener-configuration} parameter} string user
16092 The user to own the socket.
16093 Defaults to @samp{""}.
16096 @deftypevr {@code{unix-listener-configuration} parameter} string group
16097 The group to own the socket.
16098 Defaults to @samp{""}.
16102 Available @code{fifo-listener-configuration} fields are:
16104 @deftypevr {@code{fifo-listener-configuration} parameter} string path
16105 Path to the file, relative to @code{base-dir} field. This is also used as
16109 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
16110 The access mode for the socket.
16111 Defaults to @samp{"0600"}.
16114 @deftypevr {@code{fifo-listener-configuration} parameter} string user
16115 The user to own the socket.
16116 Defaults to @samp{""}.
16119 @deftypevr {@code{fifo-listener-configuration} parameter} string group
16120 The group to own the socket.
16121 Defaults to @samp{""}.
16125 Available @code{inet-listener-configuration} fields are:
16127 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
16128 The protocol to listen for.
16131 @deftypevr {@code{inet-listener-configuration} parameter} string address
16132 The address on which to listen, or empty for all addresses.
16133 Defaults to @samp{""}.
16136 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
16137 The port on which to listen.
16140 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
16141 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
16143 Defaults to @samp{#t}.
16148 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
16149 Maximum number of simultaneous client connections per process. Once
16150 this number of connections is received, the next incoming connection
16151 will prompt Dovecot to spawn another process. If set to 0,
16152 @code{default-client-limit} is used instead.
16154 Defaults to @samp{0}.
16158 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
16159 Number of connections to handle before starting a new process.
16160 Typically the only useful values are 0 (unlimited) or 1. 1 is more
16161 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
16162 Defaults to @samp{1}.
16166 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
16167 Maximum number of processes that can exist for this service. If set to
16168 0, @code{default-process-limit} is used instead.
16170 Defaults to @samp{0}.
16174 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
16175 Number of processes to always keep waiting for more connections.
16176 Defaults to @samp{0}.
16179 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
16180 If you set @samp{service-count 0}, you probably need to grow
16182 Defaults to @samp{256000000}.
16187 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
16188 Dict configuration, as created by the @code{dict-configuration}
16191 Available @code{dict-configuration} fields are:
16193 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
16194 A list of key-value pairs that this dict should hold.
16195 Defaults to @samp{()}.
16200 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
16201 A list of passdb configurations, each one created by the
16202 @code{passdb-configuration} constructor.
16204 Available @code{passdb-configuration} fields are:
16206 @deftypevr {@code{passdb-configuration} parameter} string driver
16207 The driver that the passdb should use. Valid values include
16208 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
16210 Defaults to @samp{"pam"}.
16213 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
16214 Space separated list of arguments to the passdb driver.
16215 Defaults to @samp{""}.
16220 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
16221 List of userdb configurations, each one created by the
16222 @code{userdb-configuration} constructor.
16224 Available @code{userdb-configuration} fields are:
16226 @deftypevr {@code{userdb-configuration} parameter} string driver
16227 The driver that the userdb should use. Valid values include
16228 @samp{passwd} and @samp{static}.
16229 Defaults to @samp{"passwd"}.
16232 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
16233 Space separated list of arguments to the userdb driver.
16234 Defaults to @samp{""}.
16237 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
16238 Override fields from passwd.
16239 Defaults to @samp{()}.
16244 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
16245 Plug-in configuration, created by the @code{plugin-configuration}
16249 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
16250 List of namespaces. Each item in the list is created by the
16251 @code{namespace-configuration} constructor.
16253 Available @code{namespace-configuration} fields are:
16255 @deftypevr {@code{namespace-configuration} parameter} string name
16256 Name for this namespace.
16259 @deftypevr {@code{namespace-configuration} parameter} string type
16260 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
16261 Defaults to @samp{"private"}.
16264 @deftypevr {@code{namespace-configuration} parameter} string separator
16265 Hierarchy separator to use. You should use the same separator for
16266 all namespaces or some clients get confused. @samp{/} is usually a good
16267 one. The default however depends on the underlying mail storage
16269 Defaults to @samp{""}.
16272 @deftypevr {@code{namespace-configuration} parameter} string prefix
16273 Prefix required to access this namespace. This needs to be
16274 different for all namespaces. For example @samp{Public/}.
16275 Defaults to @samp{""}.
16278 @deftypevr {@code{namespace-configuration} parameter} string location
16279 Physical location of the mailbox. This is in the same format as
16280 mail_location, which is also the default for it.
16281 Defaults to @samp{""}.
16284 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
16285 There can be only one INBOX, and this setting defines which
16287 Defaults to @samp{#f}.
16290 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
16291 If namespace is hidden, it's not advertised to clients via NAMESPACE
16292 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
16293 useful when converting from another server with different namespaces
16294 which you want to deprecate but still keep working. For example you can
16295 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
16297 Defaults to @samp{#f}.
16300 @deftypevr {@code{namespace-configuration} parameter} boolean list?
16301 Show the mailboxes under this namespace with the LIST command. This
16302 makes the namespace visible for clients that do not support the NAMESPACE
16303 extension. The special @code{children} value lists child mailboxes, but
16304 hides the namespace prefix.
16305 Defaults to @samp{#t}.
16308 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
16309 Namespace handles its own subscriptions. If set to @code{#f}, the
16310 parent namespace handles them. The empty prefix should always have this
16312 Defaults to @samp{#t}.
16315 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
16316 List of predefined mailboxes in this namespace.
16317 Defaults to @samp{()}.
16319 Available @code{mailbox-configuration} fields are:
16321 @deftypevr {@code{mailbox-configuration} parameter} string name
16322 Name for this mailbox.
16325 @deftypevr {@code{mailbox-configuration} parameter} string auto
16326 @samp{create} will automatically create this mailbox.
16327 @samp{subscribe} will both create and subscribe to the mailbox.
16328 Defaults to @samp{"no"}.
16331 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
16332 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
16333 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
16334 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
16335 Defaults to @samp{()}.
16342 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
16343 Base directory where to store runtime data.
16344 Defaults to @samp{"/var/run/dovecot/"}.
16347 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
16348 Greeting message for clients.
16349 Defaults to @samp{"Dovecot ready."}.
16352 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
16353 List of trusted network ranges. Connections from these IPs are
16354 allowed to override their IP addresses and ports (for logging and for
16355 authentication checks). @samp{disable-plaintext-auth} is also ignored
16356 for these networks. Typically you would specify your IMAP proxy servers
16358 Defaults to @samp{()}.
16361 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
16362 List of login access check sockets (e.g.@: tcpwrap).
16363 Defaults to @samp{()}.
16366 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
16367 Show more verbose process titles (in ps). Currently shows user name
16368 and IP address. Useful for seeing who is actually using the IMAP
16369 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
16371 Defaults to @samp{#f}.
16374 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
16375 Should all processes be killed when Dovecot master process shuts down.
16376 Setting this to @code{#f} means that Dovecot can be upgraded without
16377 forcing existing client connections to close (although that could also
16378 be a problem if the upgrade is e.g.@: due to a security fix).
16379 Defaults to @samp{#t}.
16382 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
16383 If non-zero, run mail commands via this many connections to doveadm
16384 server, instead of running them directly in the same process.
16385 Defaults to @samp{0}.
16388 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
16389 UNIX socket or host:port used for connecting to doveadm server.
16390 Defaults to @samp{"doveadm-server"}.
16393 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
16394 List of environment variables that are preserved on Dovecot startup
16395 and passed down to all of its child processes. You can also give
16396 key=value pairs to always set specific settings.
16399 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
16400 Disable LOGIN command and all other plaintext authentications unless
16401 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
16402 matches the local IP (i.e.@: you're connecting from the same computer),
16403 the connection is considered secure and plaintext authentication is
16404 allowed. See also ssl=required setting.
16405 Defaults to @samp{#t}.
16408 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
16409 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
16410 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
16411 for caching to be used.
16412 Defaults to @samp{0}.
16415 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
16416 Time to live for cached data. After TTL expires the cached record
16417 is no longer used, *except* if the main database lookup returns internal
16418 failure. We also try to handle password changes automatically: If
16419 user's previous authentication was successful, but this one wasn't, the
16420 cache isn't used. For now this works only with plaintext
16422 Defaults to @samp{"1 hour"}.
16425 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
16426 TTL for negative hits (user not found, password mismatch).
16427 0 disables caching them completely.
16428 Defaults to @samp{"1 hour"}.
16431 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
16432 List of realms for SASL authentication mechanisms that need them.
16433 You can leave it empty if you don't want to support multiple realms.
16434 Many clients simply use the first one listed here, so keep the default
16436 Defaults to @samp{()}.
16439 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
16440 Default realm/domain to use if none was specified. This is used for
16441 both SASL realms and appending @@domain to username in plaintext
16443 Defaults to @samp{""}.
16446 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
16447 List of allowed characters in username. If the user-given username
16448 contains a character not listed in here, the login automatically fails.
16449 This is just an extra check to make sure user can't exploit any
16450 potential quote escaping vulnerabilities with SQL/LDAP databases. If
16451 you want to allow all characters, set this value to empty.
16452 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
16455 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
16456 Username character translations before it's looked up from
16457 databases. The value contains series of from -> to characters. For
16458 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
16459 translated to @samp{@@}.
16460 Defaults to @samp{""}.
16463 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
16464 Username formatting before it's looked up from databases. You can
16465 use the standard variables here, e.g.@: %Lu would lowercase the username,
16466 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
16467 change the @samp{@@} into @samp{-AT-}. This translation is done after
16468 @samp{auth-username-translation} changes.
16469 Defaults to @samp{"%Lu"}.
16472 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
16473 If you want to allow master users to log in by specifying the master
16474 username within the normal username string (i.e.@: not using SASL
16475 mechanism's support for it), you can specify the separator character
16476 here. The format is then <username><separator><master username>.
16477 UW-IMAP uses @samp{*} as the separator, so that could be a good
16479 Defaults to @samp{""}.
16482 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
16483 Username to use for users logging in with ANONYMOUS SASL
16485 Defaults to @samp{"anonymous"}.
16488 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
16489 Maximum number of dovecot-auth worker processes. They're used to
16490 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
16491 They're automatically created and destroyed as needed.
16492 Defaults to @samp{30}.
16495 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
16496 Host name to use in GSSAPI principal names. The default is to use
16497 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
16498 allow all keytab entries.
16499 Defaults to @samp{""}.
16502 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
16503 Kerberos keytab to use for the GSSAPI mechanism. Will use the
16504 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
16505 need to change the auth service to run as root to be able to read this
16507 Defaults to @samp{""}.
16510 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
16511 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
16512 and @samp{ntlm-auth} helper.
16513 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
16514 Defaults to @samp{#f}.
16517 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
16518 Path for Samba's @samp{ntlm-auth} helper binary.
16519 Defaults to @samp{"/usr/bin/ntlm_auth"}.
16522 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
16523 Time to delay before replying to failed authentications.
16524 Defaults to @samp{"2 secs"}.
16527 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
16528 Require a valid SSL client certificate or the authentication
16530 Defaults to @samp{#f}.
16533 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
16534 Take the username from client's SSL certificate, using
16535 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
16537 Defaults to @samp{#f}.
16540 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
16541 List of wanted authentication mechanisms. Supported mechanisms are:
16542 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
16543 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
16544 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
16545 @samp{disable-plaintext-auth} setting.
16548 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
16549 List of IPs or hostnames to all director servers, including ourself.
16550 Ports can be specified as ip:port. The default port is the same as what
16551 director service's @samp{inet-listener} is using.
16552 Defaults to @samp{()}.
16555 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
16556 List of IPs or hostnames to all backend mail servers. Ranges are
16557 allowed too, like 10.0.0.10-10.0.0.30.
16558 Defaults to @samp{()}.
16561 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
16562 How long to redirect users to a specific server after it no longer
16563 has any connections.
16564 Defaults to @samp{"15 min"}.
16567 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
16568 How the username is translated before being hashed. Useful values
16569 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
16570 are shared within domain.
16571 Defaults to @samp{"%Lu"}.
16574 @deftypevr {@code{dovecot-configuration} parameter} string log-path
16575 Log file to use for error messages. @samp{syslog} logs to syslog,
16576 @samp{/dev/stderr} logs to stderr.
16577 Defaults to @samp{"syslog"}.
16580 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
16581 Log file to use for informational messages. Defaults to
16583 Defaults to @samp{""}.
16586 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
16587 Log file to use for debug messages. Defaults to
16588 @samp{info-log-path}.
16589 Defaults to @samp{""}.
16592 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
16593 Syslog facility to use if you're logging to syslog. Usually if you
16594 don't want to use @samp{mail}, you'll use local0..local7. Also other
16595 standard facilities are supported.
16596 Defaults to @samp{"mail"}.
16599 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
16600 Log unsuccessful authentication attempts and the reasons why they
16602 Defaults to @samp{#f}.
16605 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
16606 In case of password mismatches, log the attempted password. Valid
16607 values are no, plain and sha1. sha1 can be useful for detecting brute
16608 force password attempts vs. user simply trying the same password over
16609 and over again. You can also truncate the value to n chars by appending
16610 ":n" (e.g.@: sha1:6).
16611 Defaults to @samp{"no"}.
16614 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
16615 Even more verbose logging for debugging purposes. Shows for example
16617 Defaults to @samp{#f}.
16620 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
16621 In case of password mismatches, log the passwords and used scheme so
16622 the problem can be debugged. Enabling this also enables
16624 Defaults to @samp{#f}.
16627 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
16628 Enable mail process debugging. This can help you figure out why
16629 Dovecot isn't finding your mails.
16630 Defaults to @samp{#f}.
16633 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
16634 Show protocol level SSL errors.
16635 Defaults to @samp{#f}.
16638 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
16639 Prefix for each line written to log file. % codes are in
16640 strftime(3) format.
16641 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
16644 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
16645 List of elements we want to log. The elements which have a
16646 non-empty variable value are joined together to form a comma-separated
16650 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
16651 Login log format. %s contains @samp{login-log-format-elements}
16652 string, %$ contains the data we want to log.
16653 Defaults to @samp{"%$: %s"}.
16656 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
16657 Log prefix for mail processes. See doc/wiki/Variables.txt for list
16658 of possible variables you can use.
16659 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
16662 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
16663 Format to use for logging mail deliveries. You can use variables:
16666 Delivery status message (e.g.@: @samp{saved to INBOX})
16678 Defaults to @samp{"msgid=%m: %$"}.
16681 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
16682 Location for users' mailboxes. The default is empty, which means
16683 that Dovecot tries to find the mailboxes automatically. This won't work
16684 if the user doesn't yet have any mail, so you should explicitly tell
16685 Dovecot the full location.
16687 If you're using mbox, giving a path to the INBOX
16688 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
16689 where the other mailboxes are kept. This is called the "root mail
16690 directory", and it must be the first path given in the
16691 @samp{mail-location} setting.
16693 There are a few special variables you can use, eg.:
16699 user part in user@@domain, same as %u if there's no domain
16701 domain part in user@@domain, empty if there's no domain
16706 See doc/wiki/Variables.txt for full list. Some examples:
16708 @item maildir:~/Maildir
16709 @item mbox:~/mail:INBOX=/var/mail/%u
16710 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
16712 Defaults to @samp{""}.
16715 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
16716 System user and group used to access mails. If you use multiple,
16717 userdb can override these by returning uid or gid fields. You can use
16718 either numbers or names. <doc/wiki/UserIds.txt>.
16719 Defaults to @samp{""}.
16722 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16724 Defaults to @samp{""}.
16727 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16728 Group to enable temporarily for privileged operations. Currently
16729 this is used only with INBOX when either its initial creation or
16730 dotlocking fails. Typically this is set to "mail" to give access to
16732 Defaults to @samp{""}.
16735 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16736 Grant access to these supplementary groups for mail processes.
16737 Typically these are used to set up access to shared mailboxes. Note
16738 that it may be dangerous to set these if users can create
16739 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16740 could allow a user to delete others' mailboxes, or ln -s
16741 /secret/shared/box ~/mail/mybox would allow reading it).
16742 Defaults to @samp{""}.
16745 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16746 Allow full file system access to clients. There's no access checks
16747 other than what the operating system does for the active UID/GID. It
16748 works with both maildir and mboxes, allowing you to prefix mailboxes
16749 names with e.g.@: /path/ or ~user/.
16750 Defaults to @samp{#f}.
16753 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16754 Don't use mmap() at all. This is required if you store indexes to
16755 shared file systems (NFS or clustered file system).
16756 Defaults to @samp{#f}.
16759 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16760 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16761 supports @samp{O_EXCL} since version 3, so this should be safe to use
16762 nowadays by default.
16763 Defaults to @samp{#t}.
16766 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16767 When to use fsync() or fdatasync() calls:
16770 Whenever necessary to avoid losing important data
16772 Useful with e.g.@: NFS when write()s are delayed
16774 Never use it (best performance, but crashes can lose data).
16776 Defaults to @samp{"optimized"}.
16779 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16780 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16781 NFS caches whenever needed. If you're using only a single mail server
16783 Defaults to @samp{#f}.
16786 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16787 Mail index files also exist in NFS. Setting this to yes requires
16788 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16789 Defaults to @samp{#f}.
16792 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16793 Locking method for index files. Alternatives are fcntl, flock and
16794 dotlock. Dotlocking uses some tricks which may create more disk I/O
16795 than other locking methods. NFS users: flock doesn't work, remember to
16796 change @samp{mmap-disable}.
16797 Defaults to @samp{"fcntl"}.
16800 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16801 Directory in which LDA/LMTP temporarily stores incoming mails >128
16803 Defaults to @samp{"/tmp"}.
16806 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16807 Valid UID range for users. This is mostly to make sure that users can't
16808 log in as daemons or other system users. Note that denying root logins is
16809 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16811 Defaults to @samp{500}.
16814 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16816 Defaults to @samp{0}.
16819 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16820 Valid GID range for users. Users having non-valid GID as primary group ID
16821 aren't allowed to log in. If user belongs to supplementary groups with
16822 non-valid GIDs, those groups are not set.
16823 Defaults to @samp{1}.
16826 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16828 Defaults to @samp{0}.
16831 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16832 Maximum allowed length for mail keyword name. It's only forced when
16833 trying to create new keywords.
16834 Defaults to @samp{50}.
16837 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16838 List of directories under which chrooting is allowed for mail
16839 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16840 too). This setting doesn't affect @samp{login-chroot}
16841 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16842 "/./" in home dirs are ignored. WARNING: Never add directories here
16843 which local users can modify, that may lead to root exploit. Usually
16844 this should be done only if you don't allow shell access for users.
16845 <doc/wiki/Chrooting.txt>.
16846 Defaults to @samp{()}.
16849 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16850 Default chroot directory for mail processes. This can be overridden
16851 for specific users in user database by giving /./ in user's home
16852 directory (e.g.@: /home/./user chroots into /home). Note that usually
16853 there is no real need to do chrooting, Dovecot doesn't allow users to
16854 access files outside their mail directory anyway. If your home
16855 directories are prefixed with the chroot directory, append "/."@: to
16856 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16857 Defaults to @samp{""}.
16860 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16861 UNIX socket path to master authentication server to find users.
16862 This is used by imap (for shared users) and lda.
16863 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16866 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16867 Directory where to look up mail plugins.
16868 Defaults to @samp{"/usr/lib/dovecot"}.
16871 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16872 List of plugins to load for all services. Plugins specific to IMAP,
16873 LDA, etc.@: are added to this list in their own .conf files.
16874 Defaults to @samp{()}.
16877 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16878 The minimum number of mails in a mailbox before updates are done to
16879 cache file. This allows optimizing Dovecot's behavior to do less disk
16880 writes at the cost of more disk reads.
16881 Defaults to @samp{0}.
16884 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16885 When IDLE command is running, mailbox is checked once in a while to
16886 see if there are any new mails or other changes. This setting defines
16887 the minimum time to wait between those checks. Dovecot can also use
16888 dnotify, inotify and kqueue to find out immediately when changes
16890 Defaults to @samp{"30 secs"}.
16893 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16894 Save mails with CR+LF instead of plain LF. This makes sending those
16895 mails take less CPU, especially with sendfile() syscall with Linux and
16896 FreeBSD. But it also creates a bit more disk I/O which may just make it
16897 slower. Also note that if other software reads the mboxes/maildirs,
16898 they may handle the extra CRs wrong and cause problems.
16899 Defaults to @samp{#f}.
16902 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16903 By default LIST command returns all entries in maildir beginning
16904 with a dot. Enabling this option makes Dovecot return only entries
16905 which are directories. This is done by stat()ing each entry, so it
16906 causes more disk I/O.
16907 (For systems setting struct @samp{dirent->d_type} this check is free
16908 and it's done always regardless of this setting).
16909 Defaults to @samp{#f}.
16912 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16913 When copying a message, do it with hard links whenever possible.
16914 This makes the performance much better, and it's unlikely to have any
16916 Defaults to @samp{#t}.
16919 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16920 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16921 directory only when its mtime changes unexpectedly or when we can't find
16922 the mail otherwise.
16923 Defaults to @samp{#f}.
16926 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16927 Which locking methods to use for locking mbox. There are four
16932 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16933 solution. If you want to use /var/mail/ like directory, the users will
16934 need write access to that directory.
16936 Same as dotlock, but if it fails because of permissions or because there
16937 isn't enough disk space, just skip it.
16939 Use this if possible. Works with NFS too if lockd is used.
16941 May not exist in all systems. Doesn't work with NFS.
16943 May not exist in all systems. Doesn't work with NFS.
16946 You can use multiple locking methods; if you do the order they're declared
16947 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16948 locking methods as well. Some operating systems don't allow using some of
16949 them simultaneously.
16952 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16956 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16957 Maximum time to wait for lock (all of them) before aborting.
16958 Defaults to @samp{"5 mins"}.
16961 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16962 If dotlock exists but the mailbox isn't modified in any way,
16963 override the lock file after this much time.
16964 Defaults to @samp{"2 mins"}.
16967 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16968 When mbox changes unexpectedly we have to fully read it to find out
16969 what changed. If the mbox is large this can take a long time. Since
16970 the change is usually just a newly appended mail, it'd be faster to
16971 simply read the new mails. If this setting is enabled, Dovecot does
16972 this but still safely fallbacks to re-reading the whole mbox file
16973 whenever something in mbox isn't how it's expected to be. The only real
16974 downside to this setting is that if some other MUA changes message
16975 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16976 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16977 Defaults to @samp{#t}.
16980 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16981 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16982 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16983 @samp{mbox-dirty-syncs} is ignored.
16984 Defaults to @samp{#f}.
16987 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16988 Delay writing mbox headers until doing a full write sync (EXPUNGE
16989 and CHECK commands and when closing the mailbox). This is especially
16990 useful for POP3 where clients often delete all mails. The downside is
16991 that our changes aren't immediately visible to other MUAs.
16992 Defaults to @samp{#t}.
16995 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16996 If mbox size is smaller than this (e.g.@: 100k), don't write index
16997 files. If an index file already exists it's still read, just not
16999 Defaults to @samp{0}.
17002 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
17003 Maximum dbox file size until it's rotated.
17004 Defaults to @samp{10000000}.
17007 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
17008 Maximum dbox file age until it's rotated. Typically in days. Day
17009 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
17011 Defaults to @samp{"1d"}.
17014 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
17015 When creating new mdbox files, immediately preallocate their size to
17016 @samp{mdbox-rotate-size}. This setting currently works only in Linux
17017 with some file systems (ext4, xfs).
17018 Defaults to @samp{#f}.
17021 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
17022 sdbox and mdbox support saving mail attachments to external files,
17023 which also allows single instance storage for them. Other backends
17024 don't support this for now.
17026 WARNING: This feature hasn't been tested much yet. Use at your own risk.
17028 Directory root where to store mail attachments. Disabled, if empty.
17029 Defaults to @samp{""}.
17032 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
17033 Attachments smaller than this aren't saved externally. It's also
17034 possible to write a plugin to disable saving specific attachments
17036 Defaults to @samp{128000}.
17039 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
17040 File system backend to use for saving attachments:
17043 No SiS done by Dovecot (but this might help FS's own deduplication)
17045 SiS with immediate byte-by-byte comparison during saving
17046 @item sis-queue posix
17047 SiS with delayed comparison and deduplication.
17049 Defaults to @samp{"sis posix"}.
17052 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
17053 Hash format to use in attachment filenames. You can add any text and
17054 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
17055 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
17056 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
17057 Defaults to @samp{"%@{sha1@}"}.
17060 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
17062 Defaults to @samp{100}.
17065 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
17067 Defaults to @samp{1000}.
17070 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
17071 Default VSZ (virtual memory size) limit for service processes.
17072 This is mainly intended to catch and kill processes that leak memory
17073 before they eat up everything.
17074 Defaults to @samp{256000000}.
17077 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
17078 Login user is internally used by login processes. This is the most
17079 untrusted user in Dovecot system. It shouldn't have access to anything
17081 Defaults to @samp{"dovenull"}.
17084 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
17085 Internal user is used by unprivileged processes. It should be
17086 separate from login user, so that login processes can't disturb other
17088 Defaults to @samp{"dovecot"}.
17091 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
17092 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
17093 Defaults to @samp{"required"}.
17096 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
17097 PEM encoded X.509 SSL/TLS certificate (public key).
17098 Defaults to @samp{"</etc/dovecot/default.pem"}.
17101 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
17102 PEM encoded SSL/TLS private key. The key is opened before
17103 dropping root privileges, so keep the key file unreadable by anyone but
17105 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
17108 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
17109 If key file is password protected, give the password here.
17110 Alternatively give it when starting dovecot with -p parameter. Since
17111 this file is often world-readable, you may want to place this setting
17112 instead to a different.
17113 Defaults to @samp{""}.
17116 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
17117 PEM encoded trusted certificate authority. Set this only if you
17118 intend to use @samp{ssl-verify-client-cert? #t}. The file should
17119 contain the CA certificate(s) followed by the matching
17120 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
17121 Defaults to @samp{""}.
17124 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
17125 Require that CRL check succeeds for client certificates.
17126 Defaults to @samp{#t}.
17129 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
17130 Request client to send a certificate. If you also want to require
17131 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
17132 Defaults to @samp{#f}.
17135 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
17136 Which field from certificate to use for username. commonName and
17137 x500UniqueIdentifier are the usual choices. You'll also need to set
17138 @samp{auth-ssl-username-from-cert? #t}.
17139 Defaults to @samp{"commonName"}.
17142 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
17143 Minimum SSL protocol version to accept.
17144 Defaults to @samp{"TLSv1"}.
17147 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
17148 SSL ciphers to use.
17149 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
17152 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
17153 SSL crypto device to use, for valid values run "openssl engine".
17154 Defaults to @samp{""}.
17157 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
17158 Address to use when sending rejection mails.
17159 %d expands to recipient domain.
17160 Defaults to @samp{"postmaster@@%d"}.
17163 @deftypevr {@code{dovecot-configuration} parameter} string hostname
17164 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
17165 and in LMTP replies. Default is the system's real hostname@@domain.
17166 Defaults to @samp{""}.
17169 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
17170 If user is over quota, return with temporary failure instead of
17172 Defaults to @samp{#f}.
17175 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
17176 Binary to use for sending mails.
17177 Defaults to @samp{"/usr/sbin/sendmail"}.
17180 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
17181 If non-empty, send mails via this SMTP host[:port] instead of
17183 Defaults to @samp{""}.
17186 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
17187 Subject: header to use for rejection mails. You can use the same
17188 variables as for @samp{rejection-reason} below.
17189 Defaults to @samp{"Rejected: %s"}.
17192 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
17193 Human readable error message for rejection mails. You can use
17206 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
17209 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
17210 Delimiter character between local-part and detail in email
17212 Defaults to @samp{"+"}.
17215 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
17216 Header where the original recipient address (SMTP's RCPT TO:
17217 address) is taken from if not available elsewhere. With dovecot-lda -a
17218 parameter overrides this. A commonly used header for this is
17220 Defaults to @samp{""}.
17223 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
17224 Should saving a mail to a nonexistent mailbox automatically create
17226 Defaults to @samp{#f}.
17229 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
17230 Should automatically created mailboxes be also automatically
17232 Defaults to @samp{#f}.
17235 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
17236 Maximum IMAP command line length. Some clients generate very long
17237 command lines with huge mailboxes, so you may need to raise this if you
17238 get "Too long argument" or "IMAP command line too large" errors
17240 Defaults to @samp{64000}.
17243 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
17244 IMAP logout format string:
17247 total number of bytes read from client
17249 total number of bytes sent to client.
17251 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
17252 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@}"}.
17255 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
17256 Override the IMAP CAPABILITY response. If the value begins with '+',
17257 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
17258 Defaults to @samp{""}.
17261 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
17262 How long to wait between "OK Still here" notifications when client
17264 Defaults to @samp{"2 mins"}.
17267 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
17268 ID field names and values to send to clients. Using * as the value
17269 makes Dovecot use the default value. The following fields have default
17270 values currently: name, version, os, os-version, support-url,
17272 Defaults to @samp{""}.
17275 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
17276 ID fields sent by client to log. * means everything.
17277 Defaults to @samp{""}.
17280 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
17281 Workarounds for various client bugs:
17284 @item delay-newmail
17285 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
17286 CHECK commands. Some clients ignore them otherwise, for example OSX
17287 Mail (<v2.1). Outlook Express breaks more badly though, without this it
17288 may show user "Message no longer in server" errors. Note that OE6
17289 still breaks even with this workaround if synchronization is set to
17292 @item tb-extra-mailbox-sep
17293 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
17294 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
17295 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
17297 @item tb-lsub-flags
17298 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
17299 This makes Thunderbird realize they aren't selectable and show them
17300 greyed out, instead of only later giving "not selectable" popup error.
17302 Defaults to @samp{()}.
17305 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
17306 Host allowed in URLAUTH URLs sent by client. "*" allows all.
17307 Defaults to @samp{""}.
17311 Whew! Lots of configuration options. The nice thing about it though is
17312 that Guix has a complete interface to Dovecot's configuration
17313 language. This allows not only a nice way to declare configurations,
17314 but also offers reflective capabilities as well: users can write code to
17315 inspect and transform configurations from within Scheme.
17317 However, it could be that you just want to get a @code{dovecot.conf} up
17318 and running. In that case, you can pass an
17319 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
17320 @code{dovecot-service}. As its name indicates, an opaque configuration
17321 does not have easy reflective capabilities.
17323 Available @code{opaque-dovecot-configuration} fields are:
17325 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
17326 The dovecot package.
17329 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
17330 The contents of the @code{dovecot.conf}, as a string.
17333 For example, if your @code{dovecot.conf} is just the empty string, you
17334 could instantiate a dovecot service like this:
17337 (dovecot-service #:config
17338 (opaque-dovecot-configuration
17342 @subsubheading OpenSMTPD Service
17344 @deffn {Scheme Variable} opensmtpd-service-type
17345 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
17346 service, whose value should be an @code{opensmtpd-configuration} object
17347 as in this example:
17350 (service opensmtpd-service-type
17351 (opensmtpd-configuration
17352 (config-file (local-file "./my-smtpd.conf"))))
17356 @deftp {Data Type} opensmtpd-configuration
17357 Data type representing the configuration of opensmtpd.
17360 @item @code{package} (default: @var{opensmtpd})
17361 Package object of the OpenSMTPD SMTP server.
17363 @item @code{config-file} (default: @code{%default-opensmtpd-file})
17364 File-like object of the OpenSMTPD configuration file to use. By default
17365 it listens on the loopback network interface, and allows for mail from
17366 users and daemons on the local machine, as well as permitting email to
17367 remote servers. Run @command{man smtpd.conf} for more information.
17372 @subsubheading Exim Service
17374 @cindex mail transfer agent (MTA)
17375 @cindex MTA (mail transfer agent)
17378 @deffn {Scheme Variable} exim-service-type
17379 This is the type of the @uref{https://exim.org, Exim} mail transfer
17380 agent (MTA), whose value should be an @code{exim-configuration} object
17381 as in this example:
17384 (service exim-service-type
17385 (exim-configuration
17386 (config-file (local-file "./my-exim.conf"))))
17390 In order to use an @code{exim-service-type} service you must also have a
17391 @code{mail-aliases-service-type} service present in your
17392 @code{operating-system} (even if it has no aliases).
17394 @deftp {Data Type} exim-configuration
17395 Data type representing the configuration of exim.
17398 @item @code{package} (default: @var{exim})
17399 Package object of the Exim server.
17401 @item @code{config-file} (default: @code{#f})
17402 File-like object of the Exim configuration file to use. If its value is
17403 @code{#f} then use the default configuration file from the package
17404 provided in @code{package}. The resulting configuration file is loaded
17405 after setting the @code{exim_user} and @code{exim_group} configuration
17411 @subsubheading Getmail service
17416 @deffn {Scheme Variable} getmail-service-type
17417 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
17418 mail retriever, whose value should be an @code{getmail-configuration}.
17421 Available @code{getmail-configuration} fields are:
17423 @deftypevr {@code{getmail-configuration} parameter} symbol name
17424 A symbol to identify the getmail service.
17426 Defaults to @samp{"unset"}.
17430 @deftypevr {@code{getmail-configuration} parameter} package package
17431 The getmail package to use.
17435 @deftypevr {@code{getmail-configuration} parameter} string user
17436 The user to run getmail as.
17438 Defaults to @samp{"getmail"}.
17442 @deftypevr {@code{getmail-configuration} parameter} string group
17443 The group to run getmail as.
17445 Defaults to @samp{"getmail"}.
17449 @deftypevr {@code{getmail-configuration} parameter} string directory
17450 The getmail directory to use.
17452 Defaults to @samp{"/var/lib/getmail/default"}.
17456 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
17457 The getmail configuration file to use.
17459 Available @code{getmail-configuration-file} fields are:
17461 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
17462 What mail account to retrieve mail from, and how to access that account.
17464 Available @code{getmail-retriever-configuration} fields are:
17466 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
17467 The type of mail retriever to use. Valid values include @samp{passwd}
17470 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
17474 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
17475 Space separated list of arguments to the userdb driver.
17477 Defaults to @samp{unset}.
17481 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
17482 Space separated list of arguments to the userdb driver.
17484 Defaults to @samp{unset}.
17488 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
17489 Space separated list of arguments to the userdb driver.
17491 Defaults to @samp{#f}.
17495 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
17496 Override fields from passwd.
17498 Defaults to @samp{""}.
17502 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
17503 Override fields from passwd.
17505 Defaults to @samp{()}.
17509 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
17510 PEM-formatted key file to use for the TLS negotiation
17512 Defaults to @samp{""}.
17516 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
17517 PEM-formatted certificate file to use for the TLS negotiation
17519 Defaults to @samp{""}.
17523 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
17524 CA certificates to use
17526 Defaults to @samp{""}.
17530 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
17531 Extra retriever parameters
17533 Defaults to @samp{()}.
17539 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
17540 What to do with retrieved messages.
17542 Available @code{getmail-destination-configuration} fields are:
17544 @deftypevr {@code{getmail-destination-configuration} parameter} string type
17545 The type of mail destination. Valid values include @samp{Maildir},
17546 @samp{Mboxrd} and @samp{MDA_external}.
17548 Defaults to @samp{unset}.
17552 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
17553 The path option for the mail destination. The behaviour depends on the
17556 Defaults to @samp{""}.
17560 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
17561 Extra destination parameters
17563 Defaults to @samp{()}.
17569 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
17572 Available @code{getmail-options-configuration} fields are:
17574 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
17575 If set to @samp{0}, getmail will only print warnings and errors. A
17576 value of @samp{1} means that messages will be printed about retrieving
17577 and deleting messages. If set to @samp{2}, getmail will print messages
17578 about each of it's actions.
17580 Defaults to @samp{1}.
17584 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
17585 If true, getmail will retrieve all available messages. Otherwise it
17586 will only retrieve messages it hasn't seen previously.
17588 Defaults to @samp{#t}.
17592 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
17593 If set to true, messages will be deleted from the server after
17594 retrieving and successfully delivering them. Otherwise, messages will
17595 be left on the server.
17597 Defaults to @samp{#f}.
17601 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
17602 Getmail will delete messages this number of days after seeing them, if
17603 they have been delivered. This means messages will be left on the
17604 server this number of days after delivering them. A value of @samp{0}
17605 disabled this feature.
17607 Defaults to @samp{0}.
17611 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
17612 Delete messages larger than this of bytes after retrieving them, even if
17613 the delete and delete-after options are disabled. A value of @samp{0}
17614 disables this feature.
17616 Defaults to @samp{0}.
17620 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
17621 Retrieve messages totalling up to this number of bytes before closing
17622 the session with the server. A value of @samp{0} disables this feature.
17624 Defaults to @samp{0}.
17628 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
17629 Don't retrieve messages larger than this number of bytes. A value of
17630 @samp{0} disables this feature.
17632 Defaults to @samp{0}.
17636 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
17637 If true, getmail will add a Delivered-To header to messages.
17639 Defaults to @samp{#t}.
17643 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
17644 If set, getmail adds a Received header to the messages.
17646 Defaults to @samp{#t}.
17650 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
17651 Getmail will record a log of its actions to the named file. A value of
17652 @samp{""} disables this feature.
17654 Defaults to @samp{""}.
17658 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
17659 If true, getmail will record a log of its actions using the system
17662 Defaults to @samp{#t}.
17666 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
17667 If true, getmail will log information about messages not retrieved and
17668 the reason for not retrieving them, as well as starting and ending
17671 Defaults to @samp{#t}.
17675 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
17676 Extra options to include.
17678 Defaults to @samp{()}.
17686 @deftypevr {@code{getmail-configuration} parameter} list idle
17687 A list of mailboxes that getmail should wait on the server for new mail
17688 notifications. This depends on the server supporting the IDLE
17691 Defaults to @samp{()}.
17695 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
17696 Environment variables to set for getmail.
17698 Defaults to @samp{()}.
17702 @subsubheading Mail Aliases Service
17704 @cindex email aliases
17705 @cindex aliases, for email addresses
17707 @deffn {Scheme Variable} mail-aliases-service-type
17708 This is the type of the service which provides @code{/etc/aliases},
17709 specifying how to deliver mail to users on this system.
17712 (service mail-aliases-service-type
17713 '(("postmaster" "bob")
17714 ("bob" "bob@@example.com" "bob@@example2.com")))
17718 The configuration for a @code{mail-aliases-service-type} service is an
17719 association list denoting how to deliver mail that comes to this
17720 system. Each entry is of the form @code{(alias addresses ...)}, with
17721 @code{alias} specifying the local alias and @code{addresses} specifying
17722 where to deliver this user's mail.
17724 The aliases aren't required to exist as users on the local system. In
17725 the above example, there doesn't need to be a @code{postmaster} entry in
17726 the @code{operating-system}'s @code{user-accounts} in order to deliver
17727 the @code{postmaster} mail to @code{bob} (which subsequently would
17728 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
17730 @subsubheading GNU Mailutils IMAP4 Daemon
17731 @cindex GNU Mailutils IMAP4 Daemon
17733 @deffn {Scheme Variable} imap4d-service-type
17734 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
17735 mailutils, GNU Mailutils Manual}), whose value should be an
17736 @code{imap4d-configuration} object as in this example:
17739 (service imap4d-service-type
17740 (imap4d-configuration
17741 (config-file (local-file "imap4d.conf"))))
17745 @deftp {Data Type} imap4d-configuration
17746 Data type representing the configuration of @command{imap4d}.
17749 @item @code{package} (default: @code{mailutils})
17750 The package that provides @command{imap4d}.
17752 @item @code{config-file} (default: @code{%default-imap4d-config-file})
17753 File-like object of the configuration file to use, by default it will listen
17754 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
17755 Mailutils Manual}, for details.
17760 @node Messaging Services
17761 @subsection Messaging Services
17766 The @code{(gnu services messaging)} module provides Guix service
17767 definitions for messaging services: currently only Prosody is supported.
17769 @subsubheading Prosody Service
17771 @deffn {Scheme Variable} prosody-service-type
17772 This is the type for the @uref{https://prosody.im, Prosody XMPP
17773 communication server}. Its value must be a @code{prosody-configuration}
17774 record as in this example:
17777 (service prosody-service-type
17778 (prosody-configuration
17779 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
17782 (int-component-configuration
17783 (hostname "conference.example.net")
17785 (mod-muc (mod-muc-configuration)))))
17788 (virtualhost-configuration
17789 (domain "example.net"))))))
17792 See below for details about @code{prosody-configuration}.
17796 By default, Prosody does not need much configuration. Only one
17797 @code{virtualhosts} field is needed: it specifies the domain you wish
17800 You can perform various sanity checks on the generated configuration
17801 with the @code{prosodyctl check} command.
17803 Prosodyctl will also help you to import certificates from the
17804 @code{letsencrypt} directory so that the @code{prosody} user can access
17805 them. See @url{https://prosody.im/doc/letsencrypt}.
17808 prosodyctl --root cert import /etc/letsencrypt/live
17811 The available configuration parameters follow. Each parameter
17812 definition is preceded by its type; for example, @samp{string-list foo}
17813 indicates that the @code{foo} parameter should be specified as a list of
17814 strings. Types starting with @code{maybe-} denote parameters that won't
17815 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
17817 There is also a way to specify the configuration as a string, if you
17818 have an old @code{prosody.cfg.lua} file that you want to port over from
17819 some other system; see the end for more details.
17821 The @code{file-object} type designates either a file-like object
17822 (@pxref{G-Expressions, file-like objects}) or a file name.
17824 @c The following documentation was initially generated by
17825 @c (generate-documentation) in (gnu services messaging). Manually maintained
17826 @c documentation is better, so we shouldn't hesitate to edit below as
17827 @c needed. However if the change you want to make to this documentation
17828 @c can be done in an automated way, it's probably easier to change
17829 @c (generate-documentation) than to make it below and have to deal with
17830 @c the churn as Prosody updates.
17832 Available @code{prosody-configuration} fields are:
17834 @deftypevr {@code{prosody-configuration} parameter} package prosody
17835 The Prosody package.
17838 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
17839 Location of the Prosody data storage directory. See
17840 @url{https://prosody.im/doc/configure}.
17841 Defaults to @samp{"/var/lib/prosody"}.
17844 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
17845 Additional plugin directories. They are searched in all the specified
17846 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
17847 Defaults to @samp{()}.
17850 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
17851 Every virtual host and component needs a certificate so that clients and
17852 servers can securely verify its identity. Prosody will automatically load
17853 certificates/keys from the directory specified here.
17854 Defaults to @samp{"/etc/prosody/certs"}.
17857 @deftypevr {@code{prosody-configuration} parameter} string-list admins
17858 This is a list of accounts that are admins for the server. Note that you
17859 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
17860 @url{https://prosody.im/doc/creating_accounts}.
17861 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
17862 Defaults to @samp{()}.
17865 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
17866 Enable use of libevent for better performance under high load. See
17867 @url{https://prosody.im/doc/libevent}.
17868 Defaults to @samp{#f}.
17871 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
17872 This is the list of modules Prosody will load on startup. It looks for
17873 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
17874 Documentation on modules can be found at:
17875 @url{https://prosody.im/doc/modules}.
17876 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
17879 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
17880 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
17881 should you want to disable them then add them to this list.
17882 Defaults to @samp{()}.
17885 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
17886 Path to a text file where the shared groups are defined. If this path is
17887 empty then @samp{mod_groups} does nothing. See
17888 @url{https://prosody.im/doc/modules/mod_groups}.
17889 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
17892 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
17893 Disable account creation by default, for security. See
17894 @url{https://prosody.im/doc/creating_accounts}.
17895 Defaults to @samp{#f}.
17898 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
17899 These are the SSL/TLS-related settings. Most of them are disabled so to
17900 use Prosody's defaults. If you do not completely understand these options, do
17901 not add them to your config, it is easy to lower the security of your server
17902 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
17904 Available @code{ssl-configuration} fields are:
17906 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
17907 This determines what handshake to use.
17910 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
17911 Path to your private key file.
17914 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
17915 Path to your certificate file.
17918 @deftypevr {@code{ssl-configuration} parameter} file-object capath
17919 Path to directory containing root certificates that you wish Prosody to
17920 trust when verifying the certificates of remote servers.
17921 Defaults to @samp{"/etc/ssl/certs"}.
17924 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
17925 Path to a file containing root certificates that you wish Prosody to trust.
17926 Similar to @code{capath} but with all certificates concatenated together.
17929 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
17930 A list of verification options (these mostly map to OpenSSL's
17931 @code{set_verify()} flags).
17934 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
17935 A list of general options relating to SSL/TLS. These map to OpenSSL's
17936 @code{set_options()}. For a full list of options available in LuaSec, see the
17940 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
17941 How long a chain of certificate authorities to check when looking for a
17942 trusted root certificate.
17945 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
17946 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
17947 clients, and in what order.
17950 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
17951 A path to a file containing parameters for Diffie-Hellman key exchange. You
17952 can create such a file with:
17953 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
17956 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
17957 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
17958 @samp{"secp384r1"}.
17961 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
17962 A list of "extra" verification options.
17965 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
17966 Password for encrypted private keys.
17971 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
17972 Whether to force all client-to-server connections to be encrypted or not.
17973 See @url{https://prosody.im/doc/modules/mod_tls}.
17974 Defaults to @samp{#f}.
17977 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
17978 Set of mechanisms that will never be offered. See
17979 @url{https://prosody.im/doc/modules/mod_saslauth}.
17980 Defaults to @samp{("DIGEST-MD5")}.
17983 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
17984 Whether to force all server-to-server connections to be encrypted or not.
17985 See @url{https://prosody.im/doc/modules/mod_tls}.
17986 Defaults to @samp{#f}.
17989 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
17990 Whether to require encryption and certificate authentication. This
17991 provides ideal security, but requires servers you communicate with to support
17992 encryption AND present valid, trusted certificates. See
17993 @url{https://prosody.im/doc/s2s#security}.
17994 Defaults to @samp{#f}.
17997 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
17998 Many servers don't support encryption or have invalid or self-signed
17999 certificates. You can list domains here that will not be required to
18000 authenticate using certificates. They will be authenticated using DNS. See
18001 @url{https://prosody.im/doc/s2s#security}.
18002 Defaults to @samp{()}.
18005 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
18006 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
18007 valid certificates for some domains by specifying a list here. See
18008 @url{https://prosody.im/doc/s2s#security}.
18009 Defaults to @samp{()}.
18012 @deftypevr {@code{prosody-configuration} parameter} string authentication
18013 Select the authentication backend to use. The default provider stores
18014 passwords in plaintext and uses Prosody's configured data storage to store the
18015 authentication data. If you do not trust your server please see
18016 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
18017 about using the hashed backend. See also
18018 @url{https://prosody.im/doc/authentication}
18019 Defaults to @samp{"internal_plain"}.
18022 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
18023 Set logging options. Advanced logging configuration is not yet supported
18024 by the Prosody service. See @url{https://prosody.im/doc/logging}.
18025 Defaults to @samp{"*syslog"}.
18028 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
18029 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
18030 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
18033 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
18034 Maximum allowed size of the HTTP body (in bytes).
18037 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
18038 Some modules expose their own URL in various ways. This URL is built
18039 from the protocol, host and port used. If Prosody sits behind a proxy, the
18040 public URL will be @code{http-external-url} instead. See
18041 @url{https://prosody.im/doc/http#external_url}.
18044 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
18045 A host in Prosody is a domain on which user accounts can be created. For
18046 example if you want your users to have addresses like
18047 @samp{"john.smith@@example.com"} then you need to add a host
18048 @samp{"example.com"}. All options in this list will apply only to this host.
18050 Note: the name "virtual" host is used in configuration to avoid confusion with
18051 the actual physical host that Prosody is installed on. A single Prosody
18052 instance can serve many domains, each one defined as a VirtualHost entry in
18053 Prosody's configuration. Conversely a server that hosts a single domain would
18054 have just one VirtualHost entry.
18056 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
18058 Available @code{virtualhost-configuration} fields are:
18060 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:
18061 @deftypevr {@code{virtualhost-configuration} parameter} string domain
18062 Domain you wish Prosody to serve.
18067 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
18068 Components are extra services on a server which are available to clients,
18069 usually on a subdomain of the main server (such as
18070 @samp{"mycomponent.example.com"}). Example components might be chatroom
18071 servers, user directories, or gateways to other protocols.
18073 Internal components are implemented with Prosody-specific plugins. To add an
18074 internal component, you simply fill the hostname field, and the plugin you wish
18075 to use for the component.
18077 See @url{https://prosody.im/doc/components}.
18078 Defaults to @samp{()}.
18080 Available @code{int-component-configuration} fields are:
18082 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:
18083 @deftypevr {@code{int-component-configuration} parameter} string hostname
18084 Hostname of the component.
18087 @deftypevr {@code{int-component-configuration} parameter} string plugin
18088 Plugin you wish to use for the component.
18091 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
18092 Multi-user chat (MUC) is Prosody's module for allowing you to create
18093 hosted chatrooms/conferences for XMPP users.
18095 General information on setting up and using multi-user chatrooms can be found
18096 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
18097 which you should read if you are new to XMPP chatrooms.
18099 See also @url{https://prosody.im/doc/modules/mod_muc}.
18101 Available @code{mod-muc-configuration} fields are:
18103 @deftypevr {@code{mod-muc-configuration} parameter} string name
18104 The name to return in service discovery responses.
18105 Defaults to @samp{"Prosody Chatrooms"}.
18108 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
18109 If @samp{#t}, this will only allow admins to create new chatrooms.
18110 Otherwise anyone can create a room. The value @samp{"local"} restricts room
18111 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
18112 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
18113 restricts to service administrators only.
18114 Defaults to @samp{#f}.
18117 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
18118 Maximum number of history messages that will be sent to the member that has
18119 just joined the room.
18120 Defaults to @samp{20}.
18127 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
18128 External components use XEP-0114, which most standalone components
18129 support. To add an external component, you simply fill the hostname field. See
18130 @url{https://prosody.im/doc/components}.
18131 Defaults to @samp{()}.
18133 Available @code{ext-component-configuration} fields are:
18135 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:
18136 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
18137 Password which the component will use to log in.
18140 @deftypevr {@code{ext-component-configuration} parameter} string hostname
18141 Hostname of the component.
18146 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
18147 Port(s) Prosody listens on for component connections.
18148 Defaults to @samp{(5347)}.
18151 @deftypevr {@code{prosody-configuration} parameter} string component-interface
18152 Interface Prosody listens on for component connections.
18153 Defaults to @samp{"127.0.0.1"}.
18156 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
18157 Raw content that will be added to the configuration file.
18160 It could be that you just want to get a @code{prosody.cfg.lua}
18161 up and running. In that case, you can pass an
18162 @code{opaque-prosody-configuration} record as the value of
18163 @code{prosody-service-type}. As its name indicates, an opaque configuration
18164 does not have easy reflective capabilities.
18165 Available @code{opaque-prosody-configuration} fields are:
18167 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
18168 The prosody package.
18171 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
18172 The contents of the @code{prosody.cfg.lua} to use.
18175 For example, if your @code{prosody.cfg.lua} is just the empty
18176 string, you could instantiate a prosody service like this:
18179 (service prosody-service-type
18180 (opaque-prosody-configuration
18181 (prosody.cfg.lua "")))
18184 @c end of Prosody auto-generated documentation
18186 @subsubheading BitlBee Service
18188 @cindex IRC (Internet Relay Chat)
18189 @cindex IRC gateway
18190 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
18191 interface to a variety of messaging protocols such as XMPP.
18193 @defvr {Scheme Variable} bitlbee-service-type
18194 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
18195 gateway daemon. Its value is a @code{bitlbee-configuration} (see
18198 To have BitlBee listen on port 6667 on localhost, add this line to your
18202 (service bitlbee-service-type)
18206 @deftp {Data Type} bitlbee-configuration
18207 This is the configuration for BitlBee, with the following fields:
18210 @item @code{interface} (default: @code{"127.0.0.1"})
18211 @itemx @code{port} (default: @code{6667})
18212 Listen on the network interface corresponding to the IP address
18213 specified in @var{interface}, on @var{port}.
18215 When @var{interface} is @code{127.0.0.1}, only local clients can
18216 connect; when it is @code{0.0.0.0}, connections can come from any
18217 networking interface.
18219 @item @code{package} (default: @code{bitlbee})
18220 The BitlBee package to use.
18222 @item @code{plugins} (default: @code{'()})
18223 List of plugin packages to use---e.g., @code{bitlbee-discord}.
18225 @item @code{extra-settings} (default: @code{""})
18226 Configuration snippet added as-is to the BitlBee configuration file.
18230 @subsubheading Quassel Service
18232 @cindex IRC (Internet Relay Chat)
18233 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
18234 meaning that one or more clients can attach to and detach from the
18237 @defvr {Scheme Variable} quassel-service-type
18238 This is the service type for the @url{https://quassel-irc.org/,Quassel}
18239 IRC backend daemon. Its value is a @code{quassel-configuration}
18243 @deftp {Data Type} quassel-configuration
18244 This is the configuration for Quassel, with the following fields:
18247 @item @code{quassel} (default: @code{quassel})
18248 The Quassel package to use.
18250 @item @code{interface} (default: @code{"::,0.0.0.0"})
18251 @item @code{port} (default: @code{4242})
18252 Listen on the network interface(s) corresponding to the IPv4 or IPv6
18253 interfaces specified in the comma delimited @var{interface}, on
18256 @item @code{loglevel} (default: @code{"Info"})
18257 The level of logging desired. Accepted values are Debug, Info, Warning
18262 @node Telephony Services
18263 @subsection Telephony Services
18265 @cindex Murmur (VoIP server)
18266 @cindex VoIP server
18267 This section describes how to set up and run a Murmur server. Murmur is
18268 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
18271 @deftp {Data Type} murmur-configuration
18272 The service type for the Murmur server. An example configuration can
18276 (service murmur-service-type
18277 (murmur-configuration
18279 "Welcome to this Mumble server running on Guix!")
18280 (cert-required? #t) ;disallow text password logins
18281 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
18282 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
18285 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
18286 password with the command that is printed during the activation phase.
18288 It is recommended to register a normal Mumble user account
18289 and grant it admin or moderator rights.
18290 You can use the @code{mumble} client to
18291 login as new normal user, register yourself, and log out.
18292 For the next step login with the name @code{SuperUser} use
18293 the @code{SuperUser} password that you set previously,
18294 and grant your newly registered mumble user administrator or moderator
18295 rights and create some channels.
18297 Available @code{murmur-configuration} fields are:
18300 @item @code{package} (default: @code{mumble})
18301 Package that contains @code{bin/murmurd}.
18303 @item @code{user} (default: @code{"murmur"})
18304 User who will run the Murmur server.
18306 @item @code{group} (default: @code{"murmur"})
18307 Group of the user who will run the murmur server.
18309 @item @code{port} (default: @code{64738})
18310 Port on which the server will listen.
18312 @item @code{welcome-text} (default: @code{""})
18313 Welcome text sent to clients when they connect.
18315 @item @code{server-password} (default: @code{""})
18316 Password the clients have to enter in order to connect.
18318 @item @code{max-users} (default: @code{100})
18319 Maximum of users that can be connected to the server at once.
18321 @item @code{max-user-bandwidth} (default: @code{#f})
18322 Maximum voice traffic a user can send per second.
18324 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
18325 File name of the sqlite database.
18326 The service's user will become the owner of the directory.
18328 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
18329 File name of the log file.
18330 The service's user will become the owner of the directory.
18332 @item @code{autoban-attempts} (default: @code{10})
18333 Maximum number of logins a user can make in @code{autoban-timeframe}
18334 without getting auto banned for @code{autoban-time}.
18336 @item @code{autoban-timeframe} (default: @code{120})
18337 Timeframe for autoban in seconds.
18339 @item @code{autoban-time} (default: @code{300})
18340 Amount of time in seconds for which a client gets banned
18341 when violating the autoban limits.
18343 @item @code{opus-threshold} (default: @code{100})
18344 Percentage of clients that need to support opus
18345 before switching over to opus audio codec.
18347 @item @code{channel-nesting-limit} (default: @code{10})
18348 How deep channels can be nested at maximum.
18350 @item @code{channelname-regex} (default: @code{#f})
18351 A string in form of a Qt regular expression that channel names must conform to.
18353 @item @code{username-regex} (default: @code{#f})
18354 A string in form of a Qt regular expression that user names must conform to.
18356 @item @code{text-message-length} (default: @code{5000})
18357 Maximum size in bytes that a user can send in one text chat message.
18359 @item @code{image-message-length} (default: @code{(* 128 1024)})
18360 Maximum size in bytes that a user can send in one image message.
18362 @item @code{cert-required?} (default: @code{#f})
18363 If it is set to @code{#t} clients that use weak password authentication
18364 will not be accepted. Users must have completed the certificate wizard to join.
18366 @item @code{remember-channel?} (default: @code{#f})
18367 Should murmur remember the last channel each user was in when they disconnected
18368 and put them into the remembered channel when they rejoin.
18370 @item @code{allow-html?} (default: @code{#f})
18371 Should html be allowed in text messages, user comments, and channel descriptions.
18373 @item @code{allow-ping?} (default: @code{#f})
18374 Setting to true exposes the current user count, the maximum user count, and
18375 the server's maximum bandwidth per client to unauthenticated users. In the
18376 Mumble client, this information is shown in the Connect dialog.
18378 Disabling this setting will prevent public listing of the server.
18380 @item @code{bonjour?} (default: @code{#f})
18381 Should the server advertise itself in the local network through the bonjour protocol.
18383 @item @code{send-version?} (default: @code{#f})
18384 Should the murmur server version be exposed in ping requests.
18386 @item @code{log-days} (default: @code{31})
18387 Murmur also stores logs in the database, which are accessible via RPC.
18388 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
18389 or -1 to disable logging to the database.
18391 @item @code{obfuscate-ips?} (default: @code{#t})
18392 Should logged ips be obfuscated to protect the privacy of users.
18394 @item @code{ssl-cert} (default: @code{#f})
18395 File name of the SSL/TLS certificate used for encrypted connections.
18398 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
18400 @item @code{ssl-key} (default: @code{#f})
18401 Filepath to the ssl private key used for encrypted connections.
18403 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
18406 @item @code{ssl-dh-params} (default: @code{#f})
18407 File name of a PEM-encoded file with Diffie-Hellman parameters
18408 for the SSL/TLS encryption. Alternatively you set it to
18409 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
18410 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
18412 @item @code{ssl-ciphers} (default: @code{#f})
18413 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
18416 This option is specified using
18417 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
18418 OpenSSL cipher list notation}.
18420 It is recommended that you try your cipher string using 'openssl ciphers <string>'
18421 before setting it here, to get a feel for which cipher suites you will get.
18422 After setting this option, it is recommend that you inspect your Murmur log
18423 to ensure that Murmur is using the cipher suites that you expected it to.
18425 Note: Changing this option may impact the backwards compatibility of your
18426 Murmur server, and can remove the ability for older Mumble clients to be able
18429 @item @code{public-registration} (default: @code{#f})
18430 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
18432 You can optionally register your server in the public server list that the
18433 @code{mumble} client shows on startup.
18434 You cannot register your server if you have set a @code{server-password},
18435 or set @code{allow-ping} to @code{#f}.
18437 It might take a few hours until it shows up in the public list.
18439 @item @code{file} (default: @code{#f})
18440 Optional alternative override for this configuration.
18444 @deftp {Data Type} murmur-public-registration-configuration
18445 Configuration for public registration of a murmur service.
18449 This is a display name for your server. Not to be confused with the hostname.
18451 @item @code{password}
18452 A password to identify your registration.
18453 Subsequent updates will need the same password. Don't lose your password.
18456 This should be a @code{http://} or @code{https://} link to your web
18459 @item @code{hostname} (default: @code{#f})
18460 By default your server will be listed by its IP address.
18461 If it is set your server will be linked by this host name instead.
18467 @node Monitoring Services
18468 @subsection Monitoring Services
18470 @subsubheading Tailon Service
18472 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
18473 viewing and searching log files.
18475 The following example will configure the service with default values.
18476 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
18479 (service tailon-service-type)
18482 The following example customises more of the Tailon configuration,
18483 adding @command{sed} to the list of allowed commands.
18486 (service tailon-service-type
18487 (tailon-configuration
18489 (tailon-configuration-file
18490 (allowed-commands '("tail" "grep" "awk" "sed"))))))
18494 @deftp {Data Type} tailon-configuration
18495 Data type representing the configuration of Tailon.
18496 This type has the following parameters:
18499 @item @code{config-file} (default: @code{(tailon-configuration-file)})
18500 The configuration file to use for Tailon. This can be set to a
18501 @dfn{tailon-configuration-file} record value, or any gexp
18502 (@pxref{G-Expressions}).
18504 For example, to instead use a local file, the @code{local-file} function
18508 (service tailon-service-type
18509 (tailon-configuration
18510 (config-file (local-file "./my-tailon.conf"))))
18513 @item @code{package} (default: @code{tailon})
18514 The tailon package to use.
18519 @deftp {Data Type} tailon-configuration-file
18520 Data type representing the configuration options for Tailon.
18521 This type has the following parameters:
18524 @item @code{files} (default: @code{(list "/var/log")})
18525 List of files to display. The list can include strings for a single file
18526 or directory, or a list, where the first item is the name of a
18527 subsection, and the remaining items are the files or directories in that
18530 @item @code{bind} (default: @code{"localhost:8080"})
18531 Address and port to which Tailon should bind on.
18533 @item @code{relative-root} (default: @code{#f})
18534 URL path to use for Tailon, set to @code{#f} to not use a path.
18536 @item @code{allow-transfers?} (default: @code{#t})
18537 Allow downloading the log files in the web interface.
18539 @item @code{follow-names?} (default: @code{#t})
18540 Allow tailing of not-yet existent files.
18542 @item @code{tail-lines} (default: @code{200})
18543 Number of lines to read initially from each file.
18545 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
18546 Commands to allow running. By default, @code{sed} is disabled.
18548 @item @code{debug?} (default: @code{#f})
18549 Set @code{debug?} to @code{#t} to show debug messages.
18551 @item @code{wrap-lines} (default: @code{#t})
18552 Initial line wrapping state in the web interface. Set to @code{#t} to
18553 initially wrap lines (the default), or to @code{#f} to initially not
18556 @item @code{http-auth} (default: @code{#f})
18557 HTTP authentication type to use. Set to @code{#f} to disable
18558 authentication (the default). Supported values are @code{"digest"} or
18561 @item @code{users} (default: @code{#f})
18562 If HTTP authentication is enabled (see @code{http-auth}), access will be
18563 restricted to the credentials provided here. To configure users, use a
18564 list of pairs, where the first element of the pair is the username, and
18565 the 2nd element of the pair is the password.
18568 (tailon-configuration-file
18569 (http-auth "basic")
18570 (users '(("user1" . "password1")
18571 ("user2" . "password2"))))
18578 @subsubheading Darkstat Service
18580 Darkstat is a packet sniffer that captures network traffic, calculates
18581 statistics about usage, and serves reports over HTTP.
18583 @defvar {Scheme Variable} darkstat-service-type
18584 This is the service type for the
18585 @uref{https://unix4lyfe.org/darkstat/, darkstat}
18586 service, its value must be a @code{darkstat-configuration} record as in
18590 (service darkstat-service-type
18591 (darkstat-configuration
18592 (interface "eno1")))
18596 @deftp {Data Type} darkstat-configuration
18597 Data type representing the configuration of @command{darkstat}.
18600 @item @code{package} (default: @code{darkstat})
18601 The darkstat package to use.
18603 @item @code{interface}
18604 Capture traffic on the specified network interface.
18606 @item @code{port} (default: @code{"667"})
18607 Bind the web interface to the specified port.
18609 @item @code{bind-address} (default: @code{"127.0.0.1"})
18610 Bind the web interface to the specified address.
18612 @item @code{base} (default: @code{"/"})
18613 Specify the path of the base URL. This can be useful if
18614 @command{darkstat} is accessed via a reverse proxy.
18619 @subsubheading Prometheus Node Exporter Service
18621 @cindex prometheus-node-exporter
18622 The Prometheus ``node exporter'' makes hardware and operating system statistics
18623 provided by the Linux kernel available for the Prometheus monitoring system.
18624 This service should be deployed on all physical nodes and virtual machines,
18625 where monitoring these statistics is desirable.
18627 @defvar {Scheme variable} prometheus-node-exporter-service-type
18628 This is the service type for the
18629 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
18630 service, its value must be a @code{prometheus-node-exporter-configuration}
18631 record as in this example:
18634 (service prometheus-node-exporter-service-type
18635 (prometheus-node-exporter-configuration
18636 (web-listen-address ":9100")))
18640 @deftp {Data Type} prometheus-node-exporter-configuration
18641 Data type representing the configuration of @command{node_exporter}.
18644 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
18645 The prometheus-node-exporter package to use.
18647 @item @code{web-listen-address} (default: @code{":9100"})
18648 Bind the web interface to the specified address.
18653 @subsubheading Zabbix server
18654 @cindex zabbix zabbix-server
18655 Zabbix provides monitoring metrics, among others network utilization, CPU load
18656 and disk space consumption:
18659 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
18660 @item Auto-discovery of servers and network devices and interfaces.
18661 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
18662 @item Distributed monitoring with centralized web administration.
18663 @item Native high performance agents.
18664 @item SLA, and ITIL KPI metrics on reporting.
18665 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
18666 @item Remote command execution through Zabbix proxies.
18669 @c %start of fragment
18671 Available @code{zabbix-server-configuration} fields are:
18673 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
18674 The zabbix-server package.
18678 @deftypevr {@code{zabbix-server-configuration} parameter} string user
18679 User who will run the Zabbix server.
18681 Defaults to @samp{"zabbix"}.
18685 @deftypevr {@code{zabbix-server-configuration} parameter} group group
18686 Group who will run the Zabbix server.
18688 Defaults to @samp{"zabbix"}.
18692 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
18693 Database host name.
18695 Defaults to @samp{"127.0.0.1"}.
18699 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
18702 Defaults to @samp{"zabbix"}.
18706 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
18709 Defaults to @samp{"zabbix"}.
18713 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
18714 Database password. Please, use @code{include-files} with
18715 @code{DBPassword=SECRET} inside a specified file instead.
18717 Defaults to @samp{""}.
18721 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
18724 Defaults to @samp{5432}.
18728 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
18729 Specifies where log messages are written to:
18733 @code{system} - syslog.
18736 @code{file} - file specified with @code{log-file} parameter.
18739 @code{console} - standard output.
18743 Defaults to @samp{""}.
18747 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
18748 Log file name for @code{log-type} @code{file} parameter.
18750 Defaults to @samp{"/var/log/zabbix/server.log"}.
18754 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
18757 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
18761 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
18762 The location of certificate authority (CA) files for SSL server
18763 certificate verification.
18765 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
18769 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
18770 Location of SSL client certificates.
18772 Defaults to @samp{"/etc/ssl/certs"}.
18776 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
18777 Extra options will be appended to Zabbix server configuration file.
18779 Defaults to @samp{""}.
18783 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
18784 You may include individual files or all files in a directory in the
18785 configuration file.
18787 Defaults to @samp{()}.
18791 @c %end of fragment
18793 @subsubheading Zabbix agent
18794 @cindex zabbix zabbix-agent
18796 Zabbix agent gathers information for Zabbix server.
18798 @c %start of fragment
18800 Available @code{zabbix-agent-configuration} fields are:
18802 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
18803 The zabbix-agent package.
18807 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
18808 User who will run the Zabbix agent.
18810 Defaults to @samp{"zabbix"}.
18814 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
18815 Group who will run the Zabbix agent.
18817 Defaults to @samp{"zabbix"}.
18821 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
18822 Unique, case sensitive hostname which is required for active checks and
18823 must match hostname as configured on the server.
18825 Defaults to @samp{"Zabbix server"}.
18829 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
18830 Specifies where log messages are written to:
18834 @code{system} - syslog.
18837 @code{file} - file specified with @code{log-file} parameter.
18840 @code{console} - standard output.
18844 Defaults to @samp{""}.
18848 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
18849 Log file name for @code{log-type} @code{file} parameter.
18851 Defaults to @samp{"/var/log/zabbix/agent.log"}.
18855 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
18858 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
18862 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
18863 List of IP addresses, optionally in CIDR notation, or hostnames of
18864 Zabbix servers and Zabbix proxies. Incoming connections will be
18865 accepted only from the hosts listed here.
18867 Defaults to @samp{("127.0.0.1")}.
18871 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
18872 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
18873 proxies for active checks. If port is not specified, default port is
18874 used. If this parameter is not specified, active checks are disabled.
18876 Defaults to @samp{("127.0.0.1")}.
18880 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
18881 Extra options will be appended to Zabbix server configuration file.
18883 Defaults to @samp{""}.
18887 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
18888 You may include individual files or all files in a directory in the
18889 configuration file.
18891 Defaults to @samp{()}.
18895 @c %end of fragment
18897 @subsubheading Zabbix front-end
18898 @cindex zabbix zabbix-front-end
18900 This service provides a WEB interface to Zabbix server.
18902 @c %start of fragment
18904 Available @code{zabbix-front-end-configuration} fields are:
18906 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
18907 NGINX configuration.
18911 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
18912 Database host name.
18914 Defaults to @samp{"localhost"}.
18918 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
18921 Defaults to @samp{5432}.
18925 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
18928 Defaults to @samp{"zabbix"}.
18932 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
18935 Defaults to @samp{"zabbix"}.
18939 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
18940 Database password. Please, use @code{db-secret-file} instead.
18942 Defaults to @samp{""}.
18946 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
18947 Secret file which will be appended to @file{zabbix.conf.php} file. This
18948 file contains credentials for use by Zabbix front-end. You are expected
18949 to create it manually.
18951 Defaults to @samp{""}.
18955 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
18956 Zabbix server hostname.
18958 Defaults to @samp{"localhost"}.
18962 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
18963 Zabbix server port.
18965 Defaults to @samp{10051}.
18970 @c %end of fragment
18972 @node Kerberos Services
18973 @subsection Kerberos Services
18976 The @code{(gnu services kerberos)} module provides services relating to
18977 the authentication protocol @dfn{Kerberos}.
18979 @subsubheading Krb5 Service
18981 Programs using a Kerberos client library normally
18982 expect a configuration file in @file{/etc/krb5.conf}.
18983 This service generates such a file from a definition provided in the
18984 operating system declaration.
18985 It does not cause any daemon to be started.
18987 No ``keytab'' files are provided by this service---you must explicitly create them.
18988 This service is known to work with the MIT client library, @code{mit-krb5}.
18989 Other implementations have not been tested.
18991 @defvr {Scheme Variable} krb5-service-type
18992 A service type for Kerberos 5 clients.
18996 Here is an example of its use:
18998 (service krb5-service-type
18999 (krb5-configuration
19000 (default-realm "EXAMPLE.COM")
19001 (allow-weak-crypto? #t)
19004 (name "EXAMPLE.COM")
19005 (admin-server "groucho.example.com")
19006 (kdc "karl.example.com"))
19009 (admin-server "kerb-admin.argrx.edu")
19010 (kdc "keys.argrx.edu"))))))
19014 This example provides a Kerberos@tie{}5 client configuration which:
19016 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
19017 of which have distinct administration servers and key distribution centers;
19018 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
19019 specified by clients;
19020 @item Accepts services which only support encryption types known to be weak.
19023 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
19024 Only the most commonly used ones are described here.
19025 For a full list, and more detailed explanation of each, see the MIT
19026 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
19030 @deftp {Data Type} krb5-realm
19031 @cindex realm, kerberos
19034 This field is a string identifying the name of the realm.
19035 A common convention is to use the fully qualified DNS name of your organization,
19036 converted to upper case.
19038 @item @code{admin-server}
19039 This field is a string identifying the host where the administration server is
19043 This field is a string identifying the key distribution center
19048 @deftp {Data Type} krb5-configuration
19051 @item @code{allow-weak-crypto?} (default: @code{#f})
19052 If this flag is @code{#t} then services which only offer encryption algorithms
19053 known to be weak will be accepted.
19055 @item @code{default-realm} (default: @code{#f})
19056 This field should be a string identifying the default Kerberos
19057 realm for the client.
19058 You should set this field to the name of your Kerberos realm.
19059 If this value is @code{#f}
19060 then a realm must be specified with every Kerberos principal when invoking programs
19061 such as @command{kinit}.
19063 @item @code{realms}
19064 This should be a non-empty list of @code{krb5-realm} objects, which clients may
19066 Normally, one of them will have a @code{name} field matching the @code{default-realm}
19072 @subsubheading PAM krb5 Service
19075 The @code{pam-krb5} service allows for login authentication and password
19076 management via Kerberos.
19077 You will need this service if you want PAM enabled applications to authenticate
19078 users using Kerberos.
19080 @defvr {Scheme Variable} pam-krb5-service-type
19081 A service type for the Kerberos 5 PAM module.
19084 @deftp {Data Type} pam-krb5-configuration
19085 Data type representing the configuration of the Kerberos 5 PAM module.
19086 This type has the following parameters:
19088 @item @code{pam-krb5} (default: @code{pam-krb5})
19089 The pam-krb5 package to use.
19091 @item @code{minimum-uid} (default: @code{1000})
19092 The smallest user ID for which Kerberos authentications should be attempted.
19093 Local accounts with lower values will silently fail to authenticate.
19098 @node LDAP Services
19099 @subsection LDAP Services
19101 @cindex nslcd, LDAP service
19103 The @code{(gnu services authentication)} module provides the
19104 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
19105 server. In addition to configuring the service itself, you may want to add
19106 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
19107 Switch} for detailed information.
19109 Here is a simple operating system declaration with a default configuration of
19110 the @code{nslcd-service-type} and a Name Service Switch configuration that
19111 consults the @code{ldap} name service last:
19114 (use-service-modules authentication)
19115 (use-modules (gnu system nss))
19121 (service nslcd-service-type)
19122 (service dhcp-client-service-type)
19124 (name-service-switch
19125 (let ((services (list (name-service (name "db"))
19126 (name-service (name "files"))
19127 (name-service (name "ldap")))))
19128 (name-service-switch
19129 (inherit %mdns-host-lookup-nss)
19130 (password services)
19133 (netgroup services)
19134 (gshadow services)))))
19137 @c %start of generated documentation for nslcd-configuration
19139 Available @code{nslcd-configuration} fields are:
19141 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
19142 The @code{nss-pam-ldapd} package to use.
19146 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
19147 The number of threads to start that can handle requests and perform LDAP
19148 queries. Each thread opens a separate connection to the LDAP server.
19149 The default is to start 5 threads.
19151 Defaults to @samp{disabled}.
19155 @deftypevr {@code{nslcd-configuration} parameter} string uid
19156 This specifies the user id with which the daemon should be run.
19158 Defaults to @samp{"nslcd"}.
19162 @deftypevr {@code{nslcd-configuration} parameter} string gid
19163 This specifies the group id with which the daemon should be run.
19165 Defaults to @samp{"nslcd"}.
19169 @deftypevr {@code{nslcd-configuration} parameter} log-option log
19170 This option controls the way logging is done via a list containing
19171 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
19172 or "syslog", or an absolute file name. The LEVEL argument is optional
19173 and specifies the log level. The log level may be one of the following
19174 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
19175 messages with the specified log level or higher are logged.
19177 Defaults to @samp{("/var/log/nslcd" info)}.
19181 @deftypevr {@code{nslcd-configuration} parameter} list uri
19182 The list of LDAP server URIs. Normally, only the first server will be
19183 used with the following servers as fall-back.
19185 Defaults to @samp{("ldap://localhost:389/")}.
19189 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
19190 The version of the LDAP protocol to use. The default is to use the
19191 maximum version supported by the LDAP library.
19193 Defaults to @samp{disabled}.
19197 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
19198 Specifies the distinguished name with which to bind to the directory
19199 server for lookups. The default is to bind anonymously.
19201 Defaults to @samp{disabled}.
19205 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
19206 Specifies the credentials with which to bind. This option is only
19207 applicable when used with binddn.
19209 Defaults to @samp{disabled}.
19213 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
19214 Specifies the distinguished name to use when the root user tries to
19215 modify a user's password using the PAM module.
19217 Defaults to @samp{disabled}.
19221 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
19222 Specifies the credentials with which to bind if the root user tries to
19223 change a user's password. This option is only applicable when used with
19226 Defaults to @samp{disabled}.
19230 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
19231 Specifies the SASL mechanism to be used when performing SASL
19234 Defaults to @samp{disabled}.
19238 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
19239 Specifies the SASL realm to be used when performing SASL authentication.
19241 Defaults to @samp{disabled}.
19245 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
19246 Specifies the authentication identity to be used when performing SASL
19249 Defaults to @samp{disabled}.
19253 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
19254 Specifies the authorization identity to be used when performing SASL
19257 Defaults to @samp{disabled}.
19261 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
19262 Determines whether the LDAP server host name should be canonicalised. If
19263 this is enabled the LDAP library will do a reverse host name lookup. By
19264 default, it is left up to the LDAP library whether this check is
19267 Defaults to @samp{disabled}.
19271 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
19272 Set the name for the GSS-API Kerberos credentials cache.
19274 Defaults to @samp{disabled}.
19278 @deftypevr {@code{nslcd-configuration} parameter} string base
19279 The directory search base.
19281 Defaults to @samp{"dc=example,dc=com"}.
19285 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
19286 Specifies the search scope (subtree, onelevel, base or children). The
19287 default scope is subtree; base scope is almost never useful for name
19288 service lookups; children scope is not supported on all servers.
19290 Defaults to @samp{(subtree)}.
19294 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
19295 Specifies the policy for dereferencing aliases. The default policy is
19296 to never dereference aliases.
19298 Defaults to @samp{disabled}.
19302 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
19303 Specifies whether automatic referral chasing should be enabled. The
19304 default behaviour is to chase referrals.
19306 Defaults to @samp{disabled}.
19310 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
19311 This option allows for custom attributes to be looked up instead of the
19312 default RFC 2307 attributes. It is a list of maps, each consisting of
19313 the name of a map, the RFC 2307 attribute to match and the query
19314 expression for the attribute as it is available in the directory.
19316 Defaults to @samp{()}.
19320 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
19321 A list of filters consisting of the name of a map to which the filter
19322 applies and an LDAP search filter expression.
19324 Defaults to @samp{()}.
19328 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
19329 Specifies the time limit in seconds to use when connecting to the
19330 directory server. The default value is 10 seconds.
19332 Defaults to @samp{disabled}.
19336 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
19337 Specifies the time limit (in seconds) to wait for a response from the
19338 LDAP server. A value of zero, which is the default, is to wait
19339 indefinitely for searches to be completed.
19341 Defaults to @samp{disabled}.
19345 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
19346 Specifies the period if inactivity (in seconds) after which the con‐
19347 nection to the LDAP server will be closed. The default is not to time
19350 Defaults to @samp{disabled}.
19354 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
19355 Specifies the number of seconds to sleep when connecting to all LDAP
19356 servers fails. By default one second is waited between the first
19357 failure and the first retry.
19359 Defaults to @samp{disabled}.
19363 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
19364 Specifies the time after which the LDAP server is considered to be
19365 permanently unavailable. Once this time is reached retries will be done
19366 only once per this time period. The default value is 10 seconds.
19368 Defaults to @samp{disabled}.
19372 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
19373 Specifies whether to use SSL/TLS or not (the default is not to). If
19374 'start-tls is specified then StartTLS is used rather than raw LDAP over
19377 Defaults to @samp{disabled}.
19381 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
19382 Specifies what checks to perform on a server-supplied certificate. The
19383 meaning of the values is described in the ldap.conf(5) manual page.
19385 Defaults to @samp{disabled}.
19389 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
19390 Specifies the directory containing X.509 certificates for peer authen‐
19391 tication. This parameter is ignored when using GnuTLS.
19393 Defaults to @samp{disabled}.
19397 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
19398 Specifies the path to the X.509 certificate for peer authentication.
19400 Defaults to @samp{disabled}.
19404 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
19405 Specifies the path to an entropy source. This parameter is ignored when
19408 Defaults to @samp{disabled}.
19412 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
19413 Specifies the ciphers to use for TLS as a string.
19415 Defaults to @samp{disabled}.
19419 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
19420 Specifies the path to the file containing the local certificate for
19421 client TLS authentication.
19423 Defaults to @samp{disabled}.
19427 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
19428 Specifies the path to the file containing the private key for client TLS
19431 Defaults to @samp{disabled}.
19435 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
19436 Set this to a number greater than 0 to request paged results from the
19437 LDAP server in accordance with RFC2696. The default (0) is to not
19438 request paged results.
19440 Defaults to @samp{disabled}.
19444 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
19445 This option prevents group membership lookups through LDAP for the
19446 specified users. Alternatively, the value 'all-local may be used. With
19447 that value nslcd builds a full list of non-LDAP users on startup.
19449 Defaults to @samp{disabled}.
19453 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
19454 This option ensures that LDAP users with a numeric user id lower than
19455 the specified value are ignored.
19457 Defaults to @samp{disabled}.
19461 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
19462 This option specifies an offset that is added to all LDAP numeric user
19463 ids. This can be used to avoid user id collisions with local users.
19465 Defaults to @samp{disabled}.
19469 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
19470 This option specifies an offset that is added to all LDAP numeric group
19471 ids. This can be used to avoid user id collisions with local groups.
19473 Defaults to @samp{disabled}.
19477 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
19478 If this option is set, the member attribute of a group may point to
19479 another group. Members of nested groups are also returned in the higher
19480 level group and parent groups are returned when finding groups for a
19481 specific user. The default is not to perform extra searches for nested
19484 Defaults to @samp{disabled}.
19488 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
19489 If this option is set, the group member list is not retrieved when
19490 looking up groups. Lookups for finding which groups a user belongs to
19491 will remain functional so the user will likely still get the correct
19492 groups assigned on login.
19494 Defaults to @samp{disabled}.
19498 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
19499 If this option is set, functions which cause all user/group entries to
19500 be loaded from the directory will not succeed in doing so. This can
19501 dramatically reduce LDAP server load in situations where there are a
19502 great number of users and/or groups. This option is not recommended for
19503 most configurations.
19505 Defaults to @samp{disabled}.
19509 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
19510 This option can be used to specify how user and group names are verified
19511 within the system. This pattern is used to check all user and group
19512 names that are requested and returned from LDAP.
19514 Defaults to @samp{disabled}.
19518 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
19519 This specifies whether or not to perform searches using case-insensitive
19520 matching. Enabling this could open up the system to authorization
19521 bypass vulnerabilities and introduce nscd cache poisoning
19522 vulnerabilities which allow denial of service.
19524 Defaults to @samp{disabled}.
19528 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
19529 This option specifies whether password policy controls are requested and
19530 handled from the LDAP server when performing user authentication.
19532 Defaults to @samp{disabled}.
19536 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
19537 By default nslcd performs an LDAP search with the user's credentials
19538 after BIND (authentication) to ensure that the BIND operation was
19539 successful. The default search is a simple check to see if the user's
19540 DN exists. A search filter can be specified that will be used instead.
19541 It should return at least one entry.
19543 Defaults to @samp{disabled}.
19547 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
19548 This option allows flexible fine tuning of the authorisation check that
19549 should be performed. The search filter specified is executed and if any
19550 entries match, access is granted, otherwise access is denied.
19552 Defaults to @samp{disabled}.
19556 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
19557 If this option is set password modification using pam_ldap will be
19558 denied and the specified message will be presented to the user instead.
19559 The message can be used to direct the user to an alternative means of
19560 changing their password.
19562 Defaults to @samp{disabled}.
19566 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
19567 List of pam service names for which LDAP authentication should suffice.
19569 Defaults to @samp{()}.
19573 @c %end of generated documentation for nslcd-configuration
19577 @subsection Web Services
19582 The @code{(gnu services web)} module provides the Apache HTTP Server,
19583 the nginx web server, and also a fastcgi wrapper daemon.
19585 @subsubheading Apache HTTP Server
19587 @deffn {Scheme Variable} httpd-service-type
19588 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
19589 (@dfn{httpd}). The value for this service type is a
19590 @code{httpd-configuration} record.
19592 A simple example configuration is given below.
19595 (service httpd-service-type
19596 (httpd-configuration
19599 (server-name "www.example.com")
19600 (document-root "/srv/http/www.example.com")))))
19603 Other services can also extend the @code{httpd-service-type} to add to
19607 (simple-service 'www.example.com-server httpd-service-type
19611 (list (string-join '("ServerName www.example.com"
19612 "DocumentRoot /srv/http/www.example.com")
19617 The details for the @code{httpd-configuration}, @code{httpd-module},
19618 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
19621 @deffn {Data Type} httpd-configuration
19622 This data type represents the configuration for the httpd service.
19625 @item @code{package} (default: @code{httpd})
19626 The httpd package to use.
19628 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19629 The pid file used by the shepherd-service.
19631 @item @code{config} (default: @code{(httpd-config-file)})
19632 The configuration file to use with the httpd service. The default value
19633 is a @code{httpd-config-file} record, but this can also be a different
19634 G-expression that generates a file, for example a @code{plain-file}. A
19635 file outside of the store can also be specified through a string.
19640 @deffn {Data Type} httpd-module
19641 This data type represents a module for the httpd service.
19645 The name of the module.
19648 The file for the module. This can be relative to the httpd package being
19649 used, the absolute location of a file, or a G-expression for a file
19650 within the store, for example @code{(file-append mod-wsgi
19651 "/modules/mod_wsgi.so")}.
19656 @defvr {Scheme Variable} %default-httpd-modules
19657 A default list of @code{httpd-module} objects.
19660 @deffn {Data Type} httpd-config-file
19661 This data type represents a configuration file for the httpd service.
19664 @item @code{modules} (default: @code{%default-httpd-modules})
19665 The modules to load. Additional modules can be added here, or loaded by
19666 additional configuration.
19668 For example, in order to handle requests for PHP files, you can use Apache’s
19669 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
19672 (service httpd-service-type
19673 (httpd-configuration
19678 (name "proxy_module")
19679 (file "modules/mod_proxy.so"))
19681 (name "proxy_fcgi_module")
19682 (file "modules/mod_proxy_fcgi.so"))
19683 %default-httpd-modules))
19684 (extra-config (list "\
19685 <FilesMatch \\.php$>
19686 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
19687 </FilesMatch>"))))))
19688 (service php-fpm-service-type
19689 (php-fpm-configuration
19690 (socket "/var/run/php-fpm.sock")
19691 (socket-group "httpd")))
19694 @item @code{server-root} (default: @code{httpd})
19695 The @code{ServerRoot} in the configuration file, defaults to the httpd
19696 package. Directives including @code{Include} and @code{LoadModule} are
19697 taken as relative to the server root.
19699 @item @code{server-name} (default: @code{#f})
19700 The @code{ServerName} in the configuration file, used to specify the
19701 request scheme, hostname and port that the server uses to identify
19704 This doesn't need to be set in the server config, and can be specifyed
19705 in virtual hosts. The default is @code{#f} to not specify a
19708 @item @code{document-root} (default: @code{"/srv/http"})
19709 The @code{DocumentRoot} from which files will be served.
19711 @item @code{listen} (default: @code{'("80")})
19712 The list of values for the @code{Listen} directives in the config
19713 file. The value should be a list of strings, when each string can
19714 specify the port number to listen on, and optionally the IP address and
19717 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19718 The @code{PidFile} to use. This should match the @code{pid-file} set in
19719 the @code{httpd-configuration} so that the Shepherd service is
19720 configured correctly.
19722 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
19723 The @code{ErrorLog} to which the server will log errors.
19725 @item @code{user} (default: @code{"httpd"})
19726 The @code{User} which the server will answer requests as.
19728 @item @code{group} (default: @code{"httpd"})
19729 The @code{Group} which the server will answer requests as.
19731 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
19732 A flat list of strings and G-expressions which will be added to the end
19733 of the configuration file.
19735 Any values which the service is extended with will be appended to this
19741 @deffn {Data Type} httpd-virtualhost
19742 This data type represents a virtualhost configuration block for the httpd service.
19744 These should be added to the extra-config for the httpd-service.
19747 (simple-service 'www.example.com-server httpd-service-type
19751 (list (string-join '("ServerName www.example.com"
19752 "DocumentRoot /srv/http/www.example.com")
19757 @item @code{addresses-and-ports}
19758 The addresses and ports for the @code{VirtualHost} directive.
19760 @item @code{contents}
19761 The contents of the @code{VirtualHost} directive, this should be a list
19762 of strings and G-expressions.
19767 @subsubheading NGINX
19769 @deffn {Scheme Variable} nginx-service-type
19770 Service type for the @uref{https://nginx.org/,NGinx} web server. The
19771 value for this service type is a @code{<nginx-configuration>} record.
19773 A simple example configuration is given below.
19776 (service nginx-service-type
19777 (nginx-configuration
19779 (list (nginx-server-configuration
19780 (server-name '("www.example.com"))
19781 (root "/srv/http/www.example.com"))))))
19784 In addition to adding server blocks to the service configuration
19785 directly, this service can be extended by other services to add server
19786 blocks, as in this example:
19789 (simple-service 'my-extra-server nginx-service-type
19790 (list (nginx-server-configuration
19791 (root "/srv/http/extra-website")
19792 (try-files (list "$uri" "$uri/index.html")))))
19796 At startup, @command{nginx} has not yet read its configuration file, so
19797 it uses a default file to log error messages. If it fails to load its
19798 configuration file, that is where error messages are logged. After the
19799 configuration file is loaded, the default error log file changes as per
19800 configuration. In our case, startup error messages can be found in
19801 @file{/var/run/nginx/logs/error.log}, and after configuration in
19802 @file{/var/log/nginx/error.log}. The second location can be changed
19803 with the @var{log-directory} configuration option.
19805 @deffn {Data Type} nginx-configuration
19806 This data type represents the configuration for NGinx. Some
19807 configuration can be done through this and the other provided record
19808 types, or alternatively, a config file can be provided.
19811 @item @code{nginx} (default: @code{nginx})
19812 The nginx package to use.
19814 @item @code{log-directory} (default: @code{"/var/log/nginx"})
19815 The directory to which NGinx will write log files.
19817 @item @code{run-directory} (default: @code{"/var/run/nginx"})
19818 The directory in which NGinx will create a pid file, and write temporary
19821 @item @code{server-blocks} (default: @code{'()})
19822 A list of @dfn{server blocks} to create in the generated configuration
19823 file, the elements should be of type
19824 @code{<nginx-server-configuration>}.
19826 The following example would setup NGinx to serve @code{www.example.com}
19827 from the @code{/srv/http/www.example.com} directory, without using
19830 (service nginx-service-type
19831 (nginx-configuration
19833 (list (nginx-server-configuration
19834 (server-name '("www.example.com"))
19835 (root "/srv/http/www.example.com"))))))
19838 @item @code{upstream-blocks} (default: @code{'()})
19839 A list of @dfn{upstream blocks} to create in the generated configuration
19840 file, the elements should be of type
19841 @code{<nginx-upstream-configuration>}.
19843 Configuring upstreams through the @code{upstream-blocks} can be useful
19844 when combined with @code{locations} in the
19845 @code{<nginx-server-configuration>} records. The following example
19846 creates a server configuration with one location configuration, that
19847 will proxy requests to a upstream configuration, which will handle
19848 requests with two servers.
19853 (nginx-configuration
19855 (list (nginx-server-configuration
19856 (server-name '("www.example.com"))
19857 (root "/srv/http/www.example.com")
19860 (nginx-location-configuration
19862 (body '("proxy_pass http://server-proxy;"))))))))
19864 (list (nginx-upstream-configuration
19865 (name "server-proxy")
19866 (servers (list "server1.example.com"
19867 "server2.example.com")))))))
19870 @item @code{file} (default: @code{#f})
19871 If a configuration @var{file} is provided, this will be used, rather than
19872 generating a configuration file from the provided @code{log-directory},
19873 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
19874 proper operation, these arguments should match what is in @var{file} to ensure
19875 that the directories are created when the service is activated.
19877 This can be useful if you have an existing configuration file, or it's
19878 not possible to do what is required through the other parts of the
19879 nginx-configuration record.
19881 @item @code{server-names-hash-bucket-size} (default: @code{#f})
19882 Bucket size for the server names hash tables, defaults to @code{#f} to
19883 use the size of the processors cache line.
19885 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
19886 Maximum bucket size for the server names hash tables.
19888 @item @code{modules} (default: @code{'()})
19889 List of nginx dynamic modules to load. This should be a list of file
19890 names of loadable modules, as in this example:
19895 (file-append nginx-accept-language-module "\
19896 /etc/nginx/modules/ngx_http_accept_language_module.so")))
19899 @item @code{extra-content} (default: @code{""})
19900 Extra content for the @code{http} block. Should be string or a string
19901 valued G-expression.
19906 @deftp {Data Type} nginx-server-configuration
19907 Data type representing the configuration of an nginx server block.
19908 This type has the following parameters:
19911 @item @code{listen} (default: @code{'("80" "443 ssl")})
19912 Each @code{listen} directive sets the address and port for IP, or the
19913 path for a UNIX-domain socket on which the server will accept requests.
19914 Both address and port, or only address or only port can be specified.
19915 An address may also be a hostname, for example:
19918 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
19921 @item @code{server-name} (default: @code{(list 'default)})
19922 A list of server names this server represents. @code{'default} represents the
19923 default server for connections matching no other server.
19925 @item @code{root} (default: @code{"/srv/http"})
19926 Root of the website nginx will serve.
19928 @item @code{locations} (default: @code{'()})
19929 A list of @dfn{nginx-location-configuration} or
19930 @dfn{nginx-named-location-configuration} records to use within this
19933 @item @code{index} (default: @code{(list "index.html")})
19934 Index files to look for when clients ask for a directory. If it cannot be found,
19935 Nginx will send the list of files in the directory.
19937 @item @code{try-files} (default: @code{'()})
19938 A list of files whose existence is checked in the specified order.
19939 @code{nginx} will use the first file it finds to process the request.
19941 @item @code{ssl-certificate} (default: @code{#f})
19942 Where to find the certificate for secure connections. Set it to @code{#f} if
19943 you don't have a certificate or you don't want to use HTTPS.
19945 @item @code{ssl-certificate-key} (default: @code{#f})
19946 Where to find the private key for secure connections. Set it to @code{#f} if
19947 you don't have a key or you don't want to use HTTPS.
19949 @item @code{server-tokens?} (default: @code{#f})
19950 Whether the server should add its configuration to response.
19952 @item @code{raw-content} (default: @code{'()})
19953 A list of raw lines added to the server block.
19958 @deftp {Data Type} nginx-upstream-configuration
19959 Data type representing the configuration of an nginx @code{upstream}
19960 block. This type has the following parameters:
19964 Name for this group of servers.
19966 @item @code{servers}
19967 Specify the addresses of the servers in the group. The address can be
19968 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
19969 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
19970 prefix @samp{unix:}. For addresses using an IP address or domain name,
19971 the default port is 80, and a different port can be specified
19977 @deftp {Data Type} nginx-location-configuration
19978 Data type representing the configuration of an nginx @code{location}
19979 block. This type has the following parameters:
19983 URI which this location block matches.
19985 @anchor{nginx-location-configuration body}
19987 Body of the location block, specified as a list of strings. This can contain
19989 configuration directives. For example, to pass requests to a upstream
19990 server group defined using an @code{nginx-upstream-configuration} block,
19991 the following directive would be specified in the body @samp{(list "proxy_pass
19992 http://upstream-name;")}.
19997 @deftp {Data Type} nginx-named-location-configuration
19998 Data type representing the configuration of an nginx named location
19999 block. Named location blocks are used for request redirection, and not
20000 used for regular request processing. This type has the following
20005 Name to identify this location block.
20008 @xref{nginx-location-configuration body}, as the body for named location
20009 blocks can be used in a similar way to the
20010 @code{nginx-location-configuration body}. One restriction is that the
20011 body of a named location block cannot contain location blocks.
20016 @subsubheading Varnish Cache
20018 Varnish is a fast cache server that sits in between web applications
20019 and end users. It proxies requests from clients and caches the
20020 accessed URLs such that multiple requests for the same resource only
20021 creates one request to the back-end.
20023 @defvr {Scheme Variable} varnish-service-type
20024 Service type for the Varnish daemon.
20027 @deftp {Data Type} varnish-configuration
20028 Data type representing the @code{varnish} service configuration.
20029 This type has the following parameters:
20032 @item @code{package} (default: @code{varnish})
20033 The Varnish package to use.
20035 @item @code{name} (default: @code{"default"})
20036 A name for this Varnish instance. Varnish will create a directory in
20037 @file{/var/varnish/} with this name and keep temporary files there. If
20038 the name starts with a forward slash, it is interpreted as an absolute
20041 Pass the @code{-n} argument to other Varnish programs to connect to the
20042 named instance, e.g.@: @command{varnishncsa -n default}.
20044 @item @code{backend} (default: @code{"localhost:8080"})
20045 The backend to use. This option has no effect if @code{vcl} is set.
20047 @item @code{vcl} (default: #f)
20048 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
20049 is @code{#f}, Varnish will proxy @code{backend} using the default
20050 configuration. Otherwise this must be a file-like object with valid
20053 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
20054 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
20055 can do something along these lines:
20058 (define %gnu-mirror
20059 (plain-file "gnu.vcl"
20061 backend gnu @{ .host = \"www.gnu.org\"; @}"))
20065 (services (cons (service varnish-service-type
20066 (varnish-configuration
20068 (vcl %gnu-mirror)))
20072 The configuration of an already running Varnish instance can be inspected
20073 and changed using the @command{varnishadm} program.
20075 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
20076 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
20077 comprehensive documentation on Varnish and its configuration language.
20079 @item @code{listen} (default: @code{'("localhost:80")})
20080 List of addresses Varnish will listen on.
20082 @item @code{storage} (default: @code{'("malloc,128m")})
20083 List of storage backends that will be available in VCL.
20085 @item @code{parameters} (default: @code{'()})
20086 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
20088 @item @code{extra-options} (default: @code{'()})
20089 Additional arguments to pass to the @command{varnishd} process.
20094 @subsubheading Patchwork
20096 Patchwork is a patch tracking system. It can collect patches sent to a
20097 mailing list, and display them in a web interface.
20099 @defvr {Scheme Variable} patchwork-service-type
20100 Service type for Patchwork.
20103 The following example is an example of a minimal service for Patchwork, for
20104 the @code{patchwork.example.com} domain.
20107 (service patchwork-service-type
20108 (patchwork-configuration
20109 (domain "patchwork.example.com")
20111 (patchwork-settings-module
20112 (allowed-hosts (list domain))
20113 (default-from-email "patchwork@@patchwork.example.com")))
20114 (getmail-retriever-config
20115 (getmail-retriever-configuration
20116 (type "SimpleIMAPSSLRetriever")
20117 (server "imap.example.com")
20119 (username "patchwork")
20121 (list (file-append coreutils "/bin/cat")
20122 "/etc/getmail-patchwork-imap-password"))
20124 '((mailboxes . ("Patches"))))))))
20128 There are three records for configuring the Patchwork service. The
20129 @code{<patchwork-configuration>} relates to the configuration for Patchwork
20130 within the HTTPD service.
20132 The @code{settings-module} field within the @code{<patchwork-configuration>}
20133 record can be populated with the @code{<patchwork-settings-module>} record,
20134 which describes a settings module that is generated within the Guix store.
20136 For the @code{database-configuration} field within the
20137 @code{<patchwork-settings-module>}, the
20138 @code{<patchwork-database-configuration>} must be used.
20140 @deftp {Data Type} patchwork-configuration
20141 Data type representing the Patchwork service configuration. This type has the
20142 following parameters:
20145 @item @code{patchwork} (default: @code{patchwork})
20146 The Patchwork package to use.
20148 @item @code{domain}
20149 The domain to use for Patchwork, this is used in the HTTPD service virtual
20152 @item @code{settings-module}
20153 The settings module to use for Patchwork. As a Django application, Patchwork
20154 is configured with a Python module containing the settings. This can either be
20155 an instance of the @code{<patchwork-settings-module>} record, any other record
20156 that represents the settings in the store, or a directory outside of the
20159 @item @code{static-path} (default: @code{"/static/"})
20160 The path under which the HTTPD service should serve the static files.
20162 @item @code{getmail-retriever-config}
20163 The getmail-retriever-configuration record value to use with
20164 Patchwork. Getmail will be configured with this value, the messages will be
20165 delivered to Patchwork.
20170 @deftp {Data Type} patchwork-settings-module
20171 Data type representing a settings module for Patchwork. Some of these
20172 settings relate directly to Patchwork, but others relate to Django, the web
20173 framework used by Patchwork, or the Django Rest Framework library. This type
20174 has the following parameters:
20177 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
20178 The database connection settings used for Patchwork. See the
20179 @code{<patchwork-database-configuration>} record type for more information.
20181 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
20182 Patchwork, as a Django web application uses a secret key for cryptographically
20183 signing values. This file should contain a unique unpredictable value.
20185 If this file does not exist, it will be created and populated with a random
20186 value by the patchwork-setup shepherd service.
20188 This setting relates to Django.
20190 @item @code{allowed-hosts}
20191 A list of valid hosts for this Patchwork service. This should at least include
20192 the domain specified in the @code{<patchwork-configuration>} record.
20194 This is a Django setting.
20196 @item @code{default-from-email}
20197 The email address from which Patchwork should send email by default.
20199 This is a Patchwork setting.
20201 @item @code{static-url} (default: @code{#f})
20202 The URL to use when serving static assets. It can be part of a URL, or a full
20203 URL, but must end in a @code{/}.
20205 If the default value is used, the @code{static-path} value from the
20206 @code{<patchwork-configuration>} record will be used.
20208 This is a Django setting.
20210 @item @code{admins} (default: @code{'()})
20211 Email addresses to send the details of errors that occur. Each value should
20212 be a list containing two elements, the name and then the email address.
20214 This is a Django setting.
20216 @item @code{debug?} (default: @code{#f})
20217 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
20218 messages will be shown.
20220 This is a Django setting.
20222 @item @code{enable-rest-api?} (default: @code{#t})
20223 Whether to enable the Patchwork REST API.
20225 This is a Patchwork setting.
20227 @item @code{enable-xmlrpc?} (default: @code{#t})
20228 Whether to enable the XML RPC API.
20230 This is a Patchwork setting.
20232 @item @code{force-https-links?} (default: @code{#t})
20233 Whether to use HTTPS links on Patchwork pages.
20235 This is a Patchwork setting.
20237 @item @code{extra-settings} (default: @code{""})
20238 Extra code to place at the end of the Patchwork settings module.
20243 @deftp {Data Type} patchwork-database-configuration
20244 Data type representing the database configuration for Patchwork.
20247 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
20248 The database engine to use.
20250 @item @code{name} (default: @code{"patchwork"})
20251 The name of the database to use.
20253 @item @code{user} (default: @code{"httpd"})
20254 The user to connect to the database as.
20256 @item @code{password} (default: @code{""})
20257 The password to use when connecting to the database.
20259 @item @code{host} (default: @code{""})
20260 The host to make the database connection to.
20262 @item @code{port} (default: @code{""})
20263 The port on which to connect to the database.
20268 @subsubheading FastCGI
20271 FastCGI is an interface between the front-end and the back-end of a web
20272 service. It is a somewhat legacy facility; new web services should
20273 generally just talk HTTP between the front-end and the back-end.
20274 However there are a number of back-end services such as PHP or the
20275 optimized HTTP Git repository access that use FastCGI, so we have
20276 support for it in Guix.
20278 To use FastCGI, you configure the front-end web server (e.g., nginx) to
20279 dispatch some subset of its requests to the fastcgi backend, which
20280 listens on a local TCP or UNIX socket. There is an intermediary
20281 @code{fcgiwrap} program that sits between the actual backend process and
20282 the web server. The front-end indicates which backend program to run,
20283 passing that information to the @code{fcgiwrap} process.
20285 @defvr {Scheme Variable} fcgiwrap-service-type
20286 A service type for the @code{fcgiwrap} FastCGI proxy.
20289 @deftp {Data Type} fcgiwrap-configuration
20290 Data type representing the configuration of the @code{fcgiwrap} service.
20291 This type has the following parameters:
20293 @item @code{package} (default: @code{fcgiwrap})
20294 The fcgiwrap package to use.
20296 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
20297 The socket on which the @code{fcgiwrap} process should listen, as a
20298 string. Valid @var{socket} values include
20299 @code{unix:@var{/path/to/unix/socket}},
20300 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
20301 @code{tcp6:[@var{ipv6_addr}]:port}.
20303 @item @code{user} (default: @code{fcgiwrap})
20304 @itemx @code{group} (default: @code{fcgiwrap})
20305 The user and group names, as strings, under which to run the
20306 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
20307 the user asks for the specific user or group names @code{fcgiwrap} that
20308 the corresponding user and/or group is present on the system.
20310 It is possible to configure a FastCGI-backed web service to pass HTTP
20311 authentication information from the front-end to the back-end, and to
20312 allow @code{fcgiwrap} to run the back-end process as a corresponding
20313 local user. To enable this capability on the back-end, run
20314 @code{fcgiwrap} as the @code{root} user and group. Note that this
20315 capability also has to be configured on the front-end as well.
20320 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
20321 with some additional features useful for sites of any size.
20323 These features include:
20325 @item Adaptive process spawning
20326 @item Basic statistics (similar to Apache's mod_status)
20327 @item Advanced process management with graceful stop/start
20328 @item Ability to start workers with different uid/gid/chroot/environment
20329 and different php.ini (replaces safe_mode)
20330 @item Stdout & stderr logging
20331 @item Emergency restart in case of accidental opcode cache destruction
20332 @item Accelerated upload support
20333 @item Support for a "slowlog"
20334 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
20335 a special function to finish request & flush all data while continuing to do
20336 something time-consuming (video converting, stats processing, etc.)
20338 ...@: and much more.
20340 @defvr {Scheme Variable} php-fpm-service-type
20341 A Service type for @code{php-fpm}.
20344 @deftp {Data Type} php-fpm-configuration
20345 Data Type for php-fpm service configuration.
20347 @item @code{php} (default: @code{php})
20348 The php package to use.
20349 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
20350 The address on which to accept FastCGI requests. Valid syntaxes are:
20352 @item @code{"ip.add.re.ss:port"}
20353 Listen on a TCP socket to a specific address on a specific port.
20354 @item @code{"port"}
20355 Listen on a TCP socket to all addresses on a specific port.
20356 @item @code{"/path/to/unix/socket"}
20357 Listen on a unix socket.
20360 @item @code{user} (default: @code{php-fpm})
20361 User who will own the php worker processes.
20362 @item @code{group} (default: @code{php-fpm})
20363 Group of the worker processes.
20364 @item @code{socket-user} (default: @code{php-fpm})
20365 User who can speak to the php-fpm socket.
20366 @item @code{socket-group} (default: @code{nginx})
20367 Group that can speak to the php-fpm socket.
20368 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
20369 The process id of the php-fpm process is written to this file
20370 once the service has started.
20371 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
20372 Log for the php-fpm master process.
20373 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
20374 Detailed settings for the php-fpm process manager.
20377 @item @code{<php-fpm-dynamic-process-manager-configuration>}
20378 @item @code{<php-fpm-static-process-manager-configuration>}
20379 @item @code{<php-fpm-on-demand-process-manager-configuration>}
20381 @item @code{display-errors} (default @code{#f})
20382 Determines whether php errors and warning should be sent to clients
20383 and displayed in their browsers.
20384 This is useful for local php development, but a security risk for public sites,
20385 as error messages can reveal passwords and personal data.
20386 @item @code{timezone} (default @code{#f})
20387 Specifies @code{php_admin_value[date.timezone]} parameter.
20388 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
20389 This file will log the @code{stderr} outputs of php worker processes.
20390 Can be set to @code{#f} to disable logging.
20391 @item @code{file} (default @code{#f})
20392 An optional override of the whole configuration.
20393 You can use the @code{mixed-text-file} function or an absolute filepath for it.
20397 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
20398 Data Type for the @code{dynamic} php-fpm process manager. With the
20399 @code{dynamic} process manager, spare worker processes are kept around
20400 based on it's configured limits.
20402 @item @code{max-children} (default: @code{5})
20403 Maximum of worker processes.
20404 @item @code{start-servers} (default: @code{2})
20405 How many worker processes should be started on start-up.
20406 @item @code{min-spare-servers} (default: @code{1})
20407 How many spare worker processes should be kept around at minimum.
20408 @item @code{max-spare-servers} (default: @code{3})
20409 How many spare worker processes should be kept around at maximum.
20413 @deftp {Data type} php-fpm-static-process-manager-configuration
20414 Data Type for the @code{static} php-fpm process manager. With the
20415 @code{static} process manager, an unchanging number of worker processes
20418 @item @code{max-children} (default: @code{5})
20419 Maximum of worker processes.
20423 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
20424 Data Type for the @code{on-demand} php-fpm process manager. With the
20425 @code{on-demand} process manager, worker processes are only created as
20428 @item @code{max-children} (default: @code{5})
20429 Maximum of worker processes.
20430 @item @code{process-idle-timeout} (default: @code{10})
20431 The time in seconds after which a process with no requests is killed.
20436 @deffn {Scheme Procedure} nginx-php-fpm-location @
20437 [#:nginx-package nginx] @
20438 [socket (string-append "/var/run/php" @
20439 (version-major (package-version php)) @
20441 A helper function to quickly add php to an @code{nginx-server-configuration}.
20444 A simple services setup for nginx with php can look like this:
20446 (services (cons* (service dhcp-client-service-type)
20447 (service php-fpm-service-type)
20448 (service nginx-service-type
20449 (nginx-server-configuration
20450 (server-name '("example.com"))
20451 (root "/srv/http/")
20453 (list (nginx-php-fpm-location)))
20455 (ssl-certificate #f)
20456 (ssl-certificate-key #f)))
20460 @cindex cat-avatar-generator
20461 The cat avatar generator is a simple service to demonstrate the use of php-fpm
20462 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
20463 the hash of a user's email address.
20465 @deffn {Scheme Procedure} cat-avatar-generator-service @
20466 [#:cache-dir "/var/cache/cat-avatar-generator"] @
20467 [#:package cat-avatar-generator] @
20468 [#:configuration (nginx-server-configuration)]
20469 Returns an nginx-server-configuration that inherits @code{configuration}. It
20470 extends the nginx configuration to add a server block that serves @code{package},
20471 a version of cat-avatar-generator. During execution, cat-avatar-generator will
20472 be able to use @code{cache-dir} as its cache directory.
20475 A simple setup for cat-avatar-generator can look like this:
20477 (services (cons* (cat-avatar-generator-service
20479 (nginx-server-configuration
20480 (server-name '("example.com"))))
20485 @subsubheading Hpcguix-web
20487 @cindex hpcguix-web
20488 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
20489 program is a customizable web interface to browse Guix packages,
20490 initially designed for users of high-performance computing (HPC)
20493 @defvr {Scheme Variable} hpcguix-web-service-type
20494 The service type for @code{hpcguix-web}.
20497 @deftp {Data Type} hpcguix-web-configuration
20498 Data type for the hpcguix-web service configuration.
20502 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
20503 configuration. The main items available in this spec are:
20506 @item @code{title-prefix} (default: @code{"hpcguix | "})
20507 The page title prefix.
20509 @item @code{guix-command} (default: @code{"guix"})
20510 The @command{guix} command.
20512 @item @code{package-filter-proc} (default: @code{(const #t)})
20513 A procedure specifying how to filter packages that are displayed.
20515 @item @code{package-page-extension-proc} (default: @code{(const '())})
20516 Extension package for @code{hpcguix-web}.
20518 @item @code{menu} (default: @code{'()})
20519 Additional entry in page @code{menu}.
20521 @item @code{channels} (default: @code{%default-channels})
20522 List of channels from which the package list is built (@pxref{Channels}).
20524 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
20525 The expiration time, in seconds, after which the package list is rebuilt from
20526 the latest instances of the given channels.
20529 See the hpcguix-web repository for a
20530 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
20533 @item @code{package} (default: @code{hpcguix-web})
20534 The hpcguix-web package to use.
20538 A typical hpcguix-web service declaration looks like this:
20541 (service hpcguix-web-service-type
20542 (hpcguix-web-configuration
20544 #~(define site-config
20545 (hpcweb-configuration
20546 (title-prefix "Guix-HPC - ")
20547 (menu '(("/about" "ABOUT"))))))))
20551 The hpcguix-web service periodically updates the package list it publishes by
20552 pulling channels from Git. To that end, it needs to access X.509 certificates
20553 so that it can authenticate Git servers when communicating over HTTPS, and it
20554 assumes that @file{/etc/ssl/certs} contains those certificates.
20556 Thus, make sure to add @code{nss-certs} or another certificate package to the
20557 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
20558 more information on X.509 certificates.
20561 @node Certificate Services
20562 @subsection Certificate Services
20565 @cindex HTTP, HTTPS
20566 @cindex Let's Encrypt
20567 @cindex TLS certificates
20568 The @code{(gnu services certbot)} module provides a service to
20569 automatically obtain a valid TLS certificate from the Let's Encrypt
20570 certificate authority. These certificates can then be used to serve
20571 content securely over HTTPS or other TLS-based protocols, with the
20572 knowledge that the client will be able to verify the server's
20575 @url{https://letsencrypt.org/, Let's Encrypt} provides the
20576 @code{certbot} tool to automate the certification process. This tool
20577 first securely generates a key on the server. It then makes a request
20578 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
20579 checks that the request originates from the host in question by using a
20580 challenge-response protocol, requiring the server to provide its
20581 response over HTTP. If that protocol completes successfully, the CA
20582 signs the key, resulting in a certificate. That certificate is valid
20583 for a limited period of time, and therefore to continue to provide TLS
20584 services, the server needs to periodically ask the CA to renew its
20587 The certbot service automates this process: the initial key
20588 generation, the initial certification request to the Let's Encrypt
20589 service, the web server challenge/response integration, writing the
20590 certificate to disk, the automated periodic renewals, and the deployment
20591 tasks associated with the renewal (e.g.@: reloading services, copying keys
20592 with different permissions).
20594 Certbot is run twice a day, at a random minute within the hour. It
20595 won't do anything until your certificates are due for renewal or
20596 revoked, but running it regularly would give your service a chance of
20597 staying online in case a Let's Encrypt-initiated revocation happened for
20600 By using this service, you agree to the ACME Subscriber Agreement, which
20601 can be found there:
20602 @url{https://acme-v01.api.letsencrypt.org/directory}.
20604 @defvr {Scheme Variable} certbot-service-type
20605 A service type for the @code{certbot} Let's Encrypt client. Its value
20606 must be a @code{certbot-configuration} record as in this example:
20609 (define %nginx-deploy-hook
20611 "nginx-deploy-hook"
20612 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
20613 (kill pid SIGHUP))))
20615 (service certbot-service-type
20616 (certbot-configuration
20617 (email "foo@@example.net")
20620 (certificate-configuration
20621 (domains '("example.net" "www.example.net"))
20622 (deploy-hook %nginx-deploy-hook))
20623 (certificate-configuration
20624 (domains '("bar.example.net")))))))
20627 See below for details about @code{certbot-configuration}.
20630 @deftp {Data Type} certbot-configuration
20631 Data type representing the configuration of the @code{certbot} service.
20632 This type has the following parameters:
20635 @item @code{package} (default: @code{certbot})
20636 The certbot package to use.
20638 @item @code{webroot} (default: @code{/var/www})
20639 The directory from which to serve the Let's Encrypt challenge/response
20642 @item @code{certificates} (default: @code{()})
20643 A list of @code{certificates-configuration}s for which to generate
20644 certificates and request signatures. Each certificate has a @code{name}
20645 and several @code{domains}.
20648 Mandatory email used for registration, recovery contact, and important
20649 account notifications.
20651 @item @code{rsa-key-size} (default: @code{2048})
20652 Size of the RSA key.
20654 @item @code{default-location} (default: @i{see below})
20655 The default @code{nginx-location-configuration}. Because @code{certbot}
20656 needs to be able to serve challenges and responses, it needs to be able
20657 to run a web server. It does so by extending the @code{nginx} web
20658 service with an @code{nginx-server-configuration} listening on the
20659 @var{domains} on port 80, and which has a
20660 @code{nginx-location-configuration} for the @code{/.well-known/} URI
20661 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
20662 these nginx configuration data types.
20664 Requests to other URL paths will be matched by the
20665 @code{default-location}, which if present is added to all
20666 @code{nginx-server-configuration}s.
20668 By default, the @code{default-location} will issue a redirect from
20669 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
20670 you to define what to serve on your site via @code{https}.
20672 Pass @code{#f} to not issue a default location.
20676 @deftp {Data Type} certificate-configuration
20677 Data type representing the configuration of a certificate.
20678 This type has the following parameters:
20681 @item @code{name} (default: @i{see below})
20682 This name is used by Certbot for housekeeping and in file paths; it
20683 doesn't affect the content of the certificate itself. To see
20684 certificate names, run @code{certbot certificates}.
20686 Its default is the first provided domain.
20688 @item @code{domains} (default: @code{()})
20689 The first domain provided will be the subject CN of the certificate, and
20690 all domains will be Subject Alternative Names on the certificate.
20692 @item @code{challenge} (default: @code{#f})
20693 The challenge type that has to be run by certbot. If @code{#f} is specified,
20694 default to the HTTP challenge. If a value is specified, defaults to the
20695 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
20696 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
20697 and gives Let's Encrypt permission to log the public IP address of the
20698 requesting machine.
20700 @item @code{authentication-hook} (default: @code{#f})
20701 Command to be run in a shell once for each certificate challenge to be
20702 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
20703 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
20704 contains the validation string and @code{$CERTBOT_TOKEN} contains the
20705 file name of the resource requested when performing an HTTP-01 challenge.
20707 @item @code{cleanup-hook} (default: @code{#f})
20708 Command to be run in a shell once for each certificate challenge that
20709 have been answered by the @code{auth-hook}. For this command, the shell
20710 variables available in the @code{auth-hook} script are still available, and
20711 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
20712 of the @code{auth-hook} script.
20714 @item @code{deploy-hook} (default: @code{#f})
20715 Command to be run in a shell once for each successfully issued
20716 certificate. For this command, the shell variable
20717 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
20718 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
20719 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
20720 contain a space-delimited list of renewed certificate domains (for
20721 example, @samp{"example.com www.example.com"}.
20726 For each @code{certificate-configuration}, the certificate is saved to
20727 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
20728 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
20730 @subsection DNS Services
20731 @cindex DNS (domain name system)
20732 @cindex domain name system (DNS)
20734 The @code{(gnu services dns)} module provides services related to the
20735 @dfn{domain name system} (DNS). It provides a server service for hosting
20736 an @emph{authoritative} DNS server for multiple zones, slave or master.
20737 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
20738 caching and forwarding DNS server for the LAN, which uses
20739 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
20741 @subsubheading Knot Service
20743 An example configuration of an authoritative server for two zones, one master
20747 (define-zone-entries example.org.zone
20748 ;; Name TTL Class Type Data
20749 ("@@" "" "IN" "A" "127.0.0.1")
20750 ("@@" "" "IN" "NS" "ns")
20751 ("ns" "" "IN" "A" "127.0.0.1"))
20753 (define master-zone
20754 (knot-zone-configuration
20755 (domain "example.org")
20757 (origin "example.org")
20758 (entries example.org.zone)))))
20761 (knot-zone-configuration
20762 (domain "plop.org")
20763 (dnssec-policy "default")
20764 (master (list "plop-master"))))
20766 (define plop-master
20767 (knot-remote-configuration
20769 (address (list "208.76.58.171"))))
20773 (services (cons* (service knot-service-type
20774 (knot-configuration
20775 (remotes (list plop-master))
20776 (zones (list master-zone slave-zone))))
20781 @deffn {Scheme Variable} knot-service-type
20782 This is the type for the Knot DNS server.
20784 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
20785 zones, that is to say domain names you would buy from a registrar. This server
20786 is not a resolver, meaning that it can only resolve names for which it is
20787 authoritative. This server can be configured to serve zones as a master server
20788 or a slave server as a per-zone basis. Slave zones will get their data from
20789 masters, and will serve it as an authoritative server. From the point of view
20790 of a resolver, there is no difference between master and slave.
20792 The following data types are used to configure the Knot DNS server:
20795 @deftp {Data Type} knot-key-configuration
20796 Data type representing a key.
20797 This type has the following parameters:
20800 @item @code{id} (default: @code{""})
20801 An identifier for other configuration fields to refer to this key. IDs must
20802 be unique and must not be empty.
20804 @item @code{algorithm} (default: @code{#f})
20805 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
20806 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
20807 and @code{'hmac-sha512}.
20809 @item @code{secret} (default: @code{""})
20810 The secret key itself.
20815 @deftp {Data Type} knot-acl-configuration
20816 Data type representing an Access Control List (ACL) configuration.
20817 This type has the following parameters:
20820 @item @code{id} (default: @code{""})
20821 An identifier for ether configuration fields to refer to this key. IDs must be
20822 unique and must not be empty.
20824 @item @code{address} (default: @code{'()})
20825 An ordered list of IP addresses, network subnets, or network ranges represented
20826 with strings. The query must match one of them. Empty value means that
20827 address match is not required.
20829 @item @code{key} (default: @code{'()})
20830 An ordered list of references to keys represented with strings. The string
20831 must match a key ID defined in a @code{knot-key-configuration}. No key means
20832 that a key is not require to match that ACL.
20834 @item @code{action} (default: @code{'()})
20835 An ordered list of actions that are permitted or forbidden by this ACL. Possible
20836 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
20837 and @code{'update}.
20839 @item @code{deny?} (default: @code{#f})
20840 When true, the ACL defines restrictions. Listed actions are forbidden. When
20841 false, listed actions are allowed.
20846 @deftp {Data Type} zone-entry
20847 Data type represnting a record entry in a zone file.
20848 This type has the following parameters:
20851 @item @code{name} (default: @code{"@@"})
20852 The name of the record. @code{"@@"} refers to the origin of the zone. Names
20853 are relative to the origin of the zone. For example, in the @code{example.org}
20854 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
20855 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
20856 refers to @code{ns.example.org}.
20858 @item @code{ttl} (default: @code{""})
20859 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
20861 @item @code{class} (default: @code{"IN"})
20862 The class of the record. Knot currently supports only @code{"IN"} and
20863 partially @code{"CH"}.
20865 @item @code{type} (default: @code{"A"})
20866 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
20867 address), NS (Name Server) and MX (Mail eXchange). Many other types are
20870 @item @code{data} (default: @code{""})
20871 The data contained in the record. For instance an IP address associated with
20872 an A record, or a domain name associated with an NS record. Remember that
20873 domain names are relative to the origin unless they end with a dot.
20878 @deftp {Data Type} zone-file
20879 Data type representing the content of a zone file.
20880 This type has the following parameters:
20883 @item @code{entries} (default: @code{'()})
20884 The list of entries. The SOA record is taken care of, so you don't need to
20885 put it in the list of entries. This list should probably contain an entry
20886 for your primary authoritative DNS server. Other than using a list of entries
20887 directly, you can use @code{define-zone-entries} to define a object containing
20888 the list of entries more easily, that you can later pass to the @code{entries}
20889 field of the @code{zone-file}.
20891 @item @code{origin} (default: @code{""})
20892 The name of your zone. This parameter cannot be empty.
20894 @item @code{ns} (default: @code{"ns"})
20895 The domain of your primary authoritative DNS server. The name is relative to
20896 the origin, unless it ends with a dot. It is mandatory that this primary
20897 DNS server corresponds to an NS record in the zone and that it is associated
20898 to an IP address in the list of entries.
20900 @item @code{mail} (default: @code{"hostmaster"})
20901 An email address people can contact you at, as the owner of the zone. This
20902 is translated as @code{<mail>@@<origin>}.
20904 @item @code{serial} (default: @code{1})
20905 The serial number of the zone. As this is used to keep track of changes by
20906 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
20907 Always increment it when you make a change in your zone.
20909 @item @code{refresh} (default: @code{(* 2 24 3600)})
20910 The frequency at which slaves will do a zone transfer. This value is a number
20911 of seconds. It can be computed by multiplications or with
20912 @code{(string->duration)}.
20914 @item @code{retry} (default: @code{(* 15 60)})
20915 The period after which a slave will retry to contact its master when it fails
20916 to do so a first time.
20918 @item @code{expiry} (default: @code{(* 14 24 3600)})
20919 Default TTL of records. Existing records are considered correct for at most
20920 this amount of time. After this period, resolvers will invalidate their cache
20921 and check again that it still exists.
20923 @item @code{nx} (default: @code{3600})
20924 Default TTL of inexistant records. This delay is usually short because you want
20925 your new domains to reach everyone quickly.
20930 @deftp {Data Type} knot-remote-configuration
20931 Data type representing a remote configuration.
20932 This type has the following parameters:
20935 @item @code{id} (default: @code{""})
20936 An identifier for other configuration fields to refer to this remote. IDs must
20937 be unique and must not be empty.
20939 @item @code{address} (default: @code{'()})
20940 An ordered list of destination IP addresses. Addresses are tried in sequence.
20941 An optional port can be given with the @@ separator. For instance:
20942 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
20944 @item @code{via} (default: @code{'()})
20945 An ordered list of source IP addresses. An empty list will have Knot choose
20946 an appropriate source IP. An optional port can be given with the @@ separator.
20947 The default is to choose at random.
20949 @item @code{key} (default: @code{#f})
20950 A reference to a key, that is a string containing the identifier of a key
20951 defined in a @code{knot-key-configuration} field.
20956 @deftp {Data Type} knot-keystore-configuration
20957 Data type representing a keystore to hold dnssec keys.
20958 This type has the following parameters:
20961 @item @code{id} (default: @code{""})
20962 The id of the keystore. It must not be empty.
20964 @item @code{backend} (default: @code{'pem})
20965 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
20967 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
20968 The configuration string of the backend. An example for the PKCS#11 is:
20969 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
20970 For the pem backend, the string reprensents a path in the file system.
20975 @deftp {Data Type} knot-policy-configuration
20976 Data type representing a dnssec policy. Knot DNS is able to automatically
20977 sign your zones. It can either generate and manage your keys automatically or
20978 use keys that you generate.
20980 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
20981 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
20982 zone. In order to be trusted, the KSK needs to be present in the parent zone
20983 (usually a top-level domain). If your registrar supports dnssec, you will
20984 have to send them your KSK's hash so they can add a DS record in their zone.
20985 This is not automated and need to be done each time you change your KSK.
20987 The policy also defines the lifetime of keys. Usually, ZSK can be changed
20988 easily and use weaker cryptographic functions (they use lower parameters) in
20989 order to sign records quickly, so they are changed often. The KSK however
20990 requires manual interaction with the registrar, so they are changed less often
20991 and use stronger parameters because they sign only one record.
20993 This type has the following parameters:
20996 @item @code{id} (default: @code{""})
20997 The id of the policy. It must not be empty.
20999 @item @code{keystore} (default: @code{"default"})
21000 A reference to a keystore, that is a string containing the identifier of a
21001 keystore defined in a @code{knot-keystore-configuration} field. The
21002 @code{"default"} identifier means the default keystore (a kasp database that
21003 was setup by this service).
21005 @item @code{manual?} (default: @code{#f})
21006 Whether the key management is manual or automatic.
21008 @item @code{single-type-signing?} (default: @code{#f})
21009 When @code{#t}, use the Single-Type Signing Scheme.
21011 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
21012 An algorithm of signing keys and issued signatures.
21014 @item @code{ksk-size} (default: @code{256})
21015 The length of the KSK. Note that this value is correct for the default
21016 algorithm, but would be unsecure for other algorithms.
21018 @item @code{zsk-size} (default: @code{256})
21019 The length of the ZSK. Note that this value is correct for the default
21020 algorithm, but would be unsecure for other algorithms.
21022 @item @code{dnskey-ttl} (default: @code{'default})
21023 The TTL value for DNSKEY records added into zone apex. The special
21024 @code{'default} value means same as the zone SOA TTL.
21026 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
21027 The period between ZSK publication and the next rollover initiation.
21029 @item @code{propagation-delay} (default: @code{(* 24 3600)})
21030 An extra delay added for each key rollover step. This value should be high
21031 enough to cover propagation of data from the master server to all slaves.
21033 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
21034 A validity period of newly issued signatures.
21036 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
21037 A period how long before a signature expiration the signature will be refreshed.
21039 @item @code{nsec3?} (default: @code{#f})
21040 When @code{#t}, NSEC3 will be used instead of NSEC.
21042 @item @code{nsec3-iterations} (default: @code{5})
21043 The number of additional times the hashing is performed.
21045 @item @code{nsec3-salt-length} (default: @code{8})
21046 The length of a salt field in octets, which is appended to the original owner
21047 name before hashing.
21049 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
21050 The validity period of newly issued salt field.
21055 @deftp {Data Type} knot-zone-configuration
21056 Data type representing a zone served by Knot.
21057 This type has the following parameters:
21060 @item @code{domain} (default: @code{""})
21061 The domain served by this configuration. It must not be empty.
21063 @item @code{file} (default: @code{""})
21064 The file where this zone is saved. This parameter is ignored by master zones.
21065 Empty means default location that depends on the domain name.
21067 @item @code{zone} (default: @code{(zone-file)})
21068 The content of the zone file. This parameter is ignored by slave zones. It
21069 must contain a zone-file record.
21071 @item @code{master} (default: @code{'()})
21072 A list of master remotes. When empty, this zone is a master. When set, this
21073 zone is a slave. This is a list of remotes identifiers.
21075 @item @code{ddns-master} (default: @code{#f})
21076 The main master. When empty, it defaults to the first master in the list of
21079 @item @code{notify} (default: @code{'()})
21080 A list of slave remote identifiers.
21082 @item @code{acl} (default: @code{'()})
21083 A list of acl identifiers.
21085 @item @code{semantic-checks?} (default: @code{#f})
21086 When set, this adds more semantic checks to the zone.
21088 @item @code{disable-any?} (default: @code{#f})
21089 When set, this forbids queries of the ANY type.
21091 @item @code{zonefile-sync} (default: @code{0})
21092 The delay between a modification in memory and on disk. 0 means immediate
21095 @item @code{zonefile-load} (default: @code{#f})
21096 The way the zone file contents are applied during zone load. Possible values
21100 @item @code{#f} for using the default value from Knot,
21101 @item @code{'none} for not using the zone file at all,
21102 @item @code{'difference} for computing the difference between already available
21103 contents and zone contents and applying it to the current zone contents,
21104 @item @code{'difference-no-serial} for the same as @code{'difference}, but
21105 ignoring the SOA serial in the zone file, while the server takes care of it
21107 @item @code{'whole} for loading zone contents from the zone file.
21110 @item @code{journal-content} (default: @code{#f})
21111 The way the journal is used to store zone and its changes. Possible values
21112 are @code{'none} to not use it at all, @code{'changes} to store changes and
21113 @code{'all} to store contents. @code{#f} does not set this option, so the
21114 default value from Knot is used.
21116 @item @code{max-journal-usage} (default: @code{#f})
21117 The maximum size for the journal on disk. @code{#f} does not set this option,
21118 so the default value from Knot is used.
21120 @item @code{max-journal-depth} (default: @code{#f})
21121 The maximum size of the history. @code{#f} does not set this option, so the
21122 default value from Knot is used.
21124 @item @code{max-zone-size} (default: @code{#f})
21125 The maximum size of the zone file. This limit is enforced for incoming
21126 transfer and updates. @code{#f} does not set this option, so the default
21127 value from Knot is used.
21129 @item @code{dnssec-policy} (default: @code{#f})
21130 A reference to a @code{knot-policy-configuration} record, or the special
21131 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
21134 @item @code{serial-policy} (default: @code{'increment})
21135 A policy between @code{'increment} and @code{'unixtime}.
21140 @deftp {Data Type} knot-configuration
21141 Data type representing the Knot configuration.
21142 This type has the following parameters:
21145 @item @code{knot} (default: @code{knot})
21148 @item @code{run-directory} (default: @code{"/var/run/knot"})
21149 The run directory. This directory will be used for pid file and sockets.
21151 @item @code{includes} (default: @code{'()})
21152 A list of strings or file-like objects denoting other files that must be
21153 included at the top of the configuration file.
21155 @cindex secrets, Knot service
21156 This can be used to manage secrets out-of-band. For example, secret
21157 keys may be stored in an out-of-band file not managed by Guix, and
21158 thus not visible in @file{/gnu/store}---e.g., you could store secret
21159 key configuration in @file{/etc/knot/secrets.conf} and add this file
21160 to the @code{includes} list.
21162 One can generate a secret tsig key (for nsupdate and zone transfers with the
21163 keymgr command from the knot package. Note that the package is not automatically
21164 installed by the service. The following example shows how to generate a new
21168 keymgr -t mysecret > /etc/knot/secrets.conf
21169 chmod 600 /etc/knot/secrets.conf
21172 Also note that the generated key will be named @var{mysecret}, so it is the
21173 name that needs to be used in the @var{key} field of the
21174 @code{knot-acl-configuration} record and in other places that need to refer
21177 It can also be used to add configuration not supported by this interface.
21179 @item @code{listen-v4} (default: @code{"0.0.0.0"})
21180 An ip address on which to listen.
21182 @item @code{listen-v6} (default: @code{"::"})
21183 An ip address on which to listen.
21185 @item @code{listen-port} (default: @code{53})
21186 A port on which to listen.
21188 @item @code{keys} (default: @code{'()})
21189 The list of knot-key-configuration used by this configuration.
21191 @item @code{acls} (default: @code{'()})
21192 The list of knot-acl-configuration used by this configuration.
21194 @item @code{remotes} (default: @code{'()})
21195 The list of knot-remote-configuration used by this configuration.
21197 @item @code{zones} (default: @code{'()})
21198 The list of knot-zone-configuration used by this configuration.
21203 @subsubheading Knot Resolver Service
21205 @deffn {Scheme Variable} knot-resolver-service-type
21206 This this the type of the knot resolver service, whose value should be
21207 an @code{knot-resolver-configuration} object as in this example:
21210 (service knot-resolver-service-type
21211 (knot-resolver-configuration
21212 (kresd-config-file (plain-file "kresd.conf" "
21213 net.listen('192.168.0.1', 5353)
21214 user('knot-resolver', 'knot-resolver')
21215 modules = @{ 'hints > iterate', 'stats', 'predict' @}
21216 cache.size = 100 * MB
21220 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
21223 @deftp {Data Type} knot-resolver-configuration
21224 Data type representing the configuration of knot-resolver.
21227 @item @code{package} (default: @var{knot-resolver})
21228 Package object of the knot DNS resolver.
21230 @item @code{kresd-config-file} (default: %kresd.conf)
21231 File-like object of the kresd configuration file to use, by default it
21232 will listen on @code{127.0.0.1} and @code{::1}.
21234 @item @code{garbage-collection-interval} (default: 1000)
21235 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
21241 @subsubheading Dnsmasq Service
21243 @deffn {Scheme Variable} dnsmasq-service-type
21244 This is the type of the dnsmasq service, whose value should be an
21245 @code{dnsmasq-configuration} object as in this example:
21248 (service dnsmasq-service-type
21249 (dnsmasq-configuration
21251 (servers '("192.168.1.1"))))
21255 @deftp {Data Type} dnsmasq-configuration
21256 Data type representing the configuration of dnsmasq.
21259 @item @code{package} (default: @var{dnsmasq})
21260 Package object of the dnsmasq server.
21262 @item @code{no-hosts?} (default: @code{#f})
21263 When true, don't read the hostnames in /etc/hosts.
21265 @item @code{port} (default: @code{53})
21266 The port to listen on. Setting this to zero completely disables DNS
21267 responses, leaving only DHCP and/or TFTP functions.
21269 @item @code{local-service?} (default: @code{#t})
21270 Accept DNS queries only from hosts whose address is on a local subnet,
21271 ie a subnet for which an interface exists on the server.
21273 @item @code{listen-addresses} (default: @code{'()})
21274 Listen on the given IP addresses.
21276 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
21277 The file to read the IP address of the upstream nameservers from.
21279 @item @code{no-resolv?} (default: @code{#f})
21280 When true, don't read @var{resolv-file}.
21282 @item @code{servers} (default: @code{'()})
21283 Specify IP address of upstream servers directly.
21285 @item @code{cache-size} (default: @code{150})
21286 Set the size of dnsmasq's cache. Setting the cache size to zero
21289 @item @code{negative-cache?} (default: @code{#t})
21290 When false, disable negative caching.
21295 @subsubheading ddclient Service
21298 The ddclient service described below runs the ddclient daemon, which takes
21299 care of automatically updating DNS entries for service providers such as
21300 @uref{https://dyn.com/dns/, Dyn}.
21302 The following example show instantiates the service with its default
21306 (service ddclient-service-type)
21309 Note that ddclient needs to access credentials that are stored in a
21310 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
21311 @code{secret-file} below.) You are expected to create this file manually, in
21312 an ``out-of-band'' fashion (you @emph{could} make this file part of the
21313 service configuration, for instance by using @code{plain-file}, but it will be
21314 world-readable @i{via} @file{/gnu/store}.) See the examples in the
21315 @file{share/ddclient} directory of the @code{ddclient} package.
21317 @c %start of fragment
21319 Available @code{ddclient-configuration} fields are:
21321 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
21322 The ddclient package.
21326 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
21327 The period after which ddclient will retry to check IP and domain name.
21329 Defaults to @samp{300}.
21333 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
21334 Use syslog for the output.
21336 Defaults to @samp{#t}.
21340 @deftypevr {@code{ddclient-configuration} parameter} string mail
21343 Defaults to @samp{"root"}.
21347 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
21348 Mail failed update to user.
21350 Defaults to @samp{"root"}.
21354 @deftypevr {@code{ddclient-configuration} parameter} string pid
21355 The ddclient PID file.
21357 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
21361 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
21362 Enable SSL support.
21364 Defaults to @samp{#t}.
21368 @deftypevr {@code{ddclient-configuration} parameter} string user
21369 Specifies the user name or ID that is used when running ddclient
21372 Defaults to @samp{"ddclient"}.
21376 @deftypevr {@code{ddclient-configuration} parameter} string group
21377 Group of the user who will run the ddclient program.
21379 Defaults to @samp{"ddclient"}.
21383 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
21384 Secret file which will be appended to @file{ddclient.conf} file. This
21385 file contains credentials for use by ddclient. You are expected to
21386 create it manually.
21388 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
21392 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
21393 Extra options will be appended to @file{ddclient.conf} file.
21395 Defaults to @samp{()}.
21400 @c %end of fragment
21404 @subsection VPN Services
21405 @cindex VPN (virtual private network)
21406 @cindex virtual private network (VPN)
21408 The @code{(gnu services vpn)} module provides services related to
21409 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
21410 your machine to connect to a VPN, and a @emph{server} service for your machine
21411 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
21413 @deffn {Scheme Procedure} openvpn-client-service @
21414 [#:config (openvpn-client-configuration)]
21416 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
21419 @deffn {Scheme Procedure} openvpn-server-service @
21420 [#:config (openvpn-server-configuration)]
21422 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
21424 Both can be run simultaneously.
21427 @c %automatically generated documentation
21429 Available @code{openvpn-client-configuration} fields are:
21431 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
21432 The OpenVPN package.
21436 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
21437 The OpenVPN pid file.
21439 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21443 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
21444 The protocol (UDP or TCP) used to open a channel between clients and
21447 Defaults to @samp{udp}.
21451 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
21452 The device type used to represent the VPN connection.
21454 Defaults to @samp{tun}.
21458 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
21459 The certificate authority to check connections against.
21461 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21465 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
21466 The certificate of the machine the daemon is running on. It should be
21467 signed by the authority given in @code{ca}.
21469 Defaults to @samp{"/etc/openvpn/client.crt"}.
21473 @deftypevr {@code{openvpn-client-configuration} parameter} string key
21474 The key of the machine the daemon is running on. It must be the key whose
21475 certificate is @code{cert}.
21477 Defaults to @samp{"/etc/openvpn/client.key"}.
21481 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
21482 Whether to use the lzo compression algorithm.
21484 Defaults to @samp{#t}.
21488 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
21489 Don't re-read key files across SIGUSR1 or --ping-restart.
21491 Defaults to @samp{#t}.
21495 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
21496 Don't close and reopen TUN/TAP device or run up/down scripts across
21497 SIGUSR1 or --ping-restart restarts.
21499 Defaults to @samp{#t}.
21503 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
21506 Defaults to @samp{3}.
21510 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
21511 Add an additional layer of HMAC authentication on top of the TLS control
21512 channel to protect against DoS attacks.
21514 Defaults to @samp{#f}.
21518 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
21519 Whether to check the server certificate has server usage extension.
21521 Defaults to @samp{#t}.
21525 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
21526 Bind to a specific local port number.
21528 Defaults to @samp{#f}.
21532 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
21533 Retry resolving server address.
21535 Defaults to @samp{#t}.
21539 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
21540 A list of remote servers to connect to.
21542 Defaults to @samp{()}.
21544 Available @code{openvpn-remote-configuration} fields are:
21546 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
21549 Defaults to @samp{"my-server"}.
21553 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
21554 Port number the server listens to.
21556 Defaults to @samp{1194}.
21561 @c %end of automatic openvpn-client documentation
21563 @c %automatically generated documentation
21565 Available @code{openvpn-server-configuration} fields are:
21567 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
21568 The OpenVPN package.
21572 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
21573 The OpenVPN pid file.
21575 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21579 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
21580 The protocol (UDP or TCP) used to open a channel between clients and
21583 Defaults to @samp{udp}.
21587 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
21588 The device type used to represent the VPN connection.
21590 Defaults to @samp{tun}.
21594 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
21595 The certificate authority to check connections against.
21597 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21601 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
21602 The certificate of the machine the daemon is running on. It should be
21603 signed by the authority given in @code{ca}.
21605 Defaults to @samp{"/etc/openvpn/client.crt"}.
21609 @deftypevr {@code{openvpn-server-configuration} parameter} string key
21610 The key of the machine the daemon is running on. It must be the key whose
21611 certificate is @code{cert}.
21613 Defaults to @samp{"/etc/openvpn/client.key"}.
21617 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
21618 Whether to use the lzo compression algorithm.
21620 Defaults to @samp{#t}.
21624 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
21625 Don't re-read key files across SIGUSR1 or --ping-restart.
21627 Defaults to @samp{#t}.
21631 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
21632 Don't close and reopen TUN/TAP device or run up/down scripts across
21633 SIGUSR1 or --ping-restart restarts.
21635 Defaults to @samp{#t}.
21639 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
21642 Defaults to @samp{3}.
21646 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
21647 Add an additional layer of HMAC authentication on top of the TLS control
21648 channel to protect against DoS attacks.
21650 Defaults to @samp{#f}.
21654 @deftypevr {@code{openvpn-server-configuration} parameter} number port
21655 Specifies the port number on which the server listens.
21657 Defaults to @samp{1194}.
21661 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
21662 An ip and mask specifying the subnet inside the virtual network.
21664 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
21668 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
21669 A CIDR notation specifying the IPv6 subnet inside the virtual network.
21671 Defaults to @samp{#f}.
21675 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
21676 The Diffie-Hellman parameters file.
21678 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
21682 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
21683 The file that records client IPs.
21685 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
21689 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
21690 When true, the server will act as a gateway for its clients.
21692 Defaults to @samp{#f}.
21696 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
21697 When true, clients are allowed to talk to each other inside the VPN.
21699 Defaults to @samp{#f}.
21703 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
21704 Causes ping-like messages to be sent back and forth over the link so
21705 that each side knows when the other side has gone down. @code{keepalive}
21706 requires a pair. The first element is the period of the ping sending,
21707 and the second element is the timeout before considering the other side
21712 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
21713 The maximum number of clients.
21715 Defaults to @samp{100}.
21719 @deftypevr {@code{openvpn-server-configuration} parameter} string status
21720 The status file. This file shows a small report on current connection.
21721 It is truncated and rewritten every minute.
21723 Defaults to @samp{"/var/run/openvpn/status"}.
21727 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
21728 The list of configuration for some clients.
21730 Defaults to @samp{()}.
21732 Available @code{openvpn-ccd-configuration} fields are:
21734 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
21737 Defaults to @samp{"client"}.
21741 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
21744 Defaults to @samp{#f}.
21748 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
21751 Defaults to @samp{#f}.
21758 @c %end of automatic openvpn-server documentation
21761 @node Network File System
21762 @subsection Network File System
21765 The @code{(gnu services nfs)} module provides the following services,
21766 which are most commonly used in relation to mounting or exporting
21767 directory trees as @dfn{network file systems} (NFS).
21769 @subsubheading RPC Bind Service
21772 The RPC Bind service provides a facility to map program numbers into
21773 universal addresses.
21774 Many NFS related services use this facility. Hence it is automatically
21775 started when a dependent service starts.
21777 @defvr {Scheme Variable} rpcbind-service-type
21778 A service type for the RPC portmapper daemon.
21782 @deftp {Data Type} rpcbind-configuration
21783 Data type representing the configuration of the RPC Bind Service.
21784 This type has the following parameters:
21786 @item @code{rpcbind} (default: @code{rpcbind})
21787 The rpcbind package to use.
21789 @item @code{warm-start?} (default: @code{#t})
21790 If this parameter is @code{#t}, then the daemon will read a
21791 state file on startup thus reloading state information saved by a previous
21797 @subsubheading Pipefs Pseudo File System
21801 The pipefs file system is used to transfer NFS related data
21802 between the kernel and user space programs.
21804 @defvr {Scheme Variable} pipefs-service-type
21805 A service type for the pipefs pseudo file system.
21808 @deftp {Data Type} pipefs-configuration
21809 Data type representing the configuration of the pipefs pseudo file system service.
21810 This type has the following parameters:
21812 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21813 The directory to which the file system is to be attached.
21818 @subsubheading GSS Daemon Service
21821 @cindex global security system
21823 The @dfn{global security system} (GSS) daemon provides strong security for RPC
21825 Before exchanging RPC requests an RPC client must establish a security
21826 context. Typically this is done using the Kerberos command @command{kinit}
21827 or automatically at login time using PAM services (@pxref{Kerberos Services}).
21829 @defvr {Scheme Variable} gss-service-type
21830 A service type for the Global Security System (GSS) daemon.
21833 @deftp {Data Type} gss-configuration
21834 Data type representing the configuration of the GSS daemon service.
21835 This type has the following parameters:
21837 @item @code{nfs-utils} (default: @code{nfs-utils})
21838 The package in which the @command{rpc.gssd} command is to be found.
21840 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21841 The directory where the pipefs file system is mounted.
21847 @subsubheading IDMAP Daemon Service
21849 @cindex name mapper
21851 The idmap daemon service provides mapping between user IDs and user names.
21852 Typically it is required in order to access file systems mounted via NFSv4.
21854 @defvr {Scheme Variable} idmap-service-type
21855 A service type for the Identity Mapper (IDMAP) daemon.
21858 @deftp {Data Type} idmap-configuration
21859 Data type representing the configuration of the IDMAP daemon service.
21860 This type has the following parameters:
21862 @item @code{nfs-utils} (default: @code{nfs-utils})
21863 The package in which the @command{rpc.idmapd} command is to be found.
21865 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21866 The directory where the pipefs file system is mounted.
21868 @item @code{domain} (default: @code{#f})
21869 The local NFSv4 domain name.
21870 This must be a string or @code{#f}.
21871 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
21876 @node Continuous Integration
21877 @subsection Continuous Integration
21879 @cindex continuous integration
21880 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
21881 continuous integration tool for Guix. It can be used both for development and
21882 for providing substitutes to others (@pxref{Substitutes}).
21884 The @code{(gnu services cuirass)} module provides the following service.
21886 @defvr {Scheme Procedure} cuirass-service-type
21887 The type of the Cuirass service. Its value must be a
21888 @code{cuirass-configuration} object, as described below.
21891 To add build jobs, you have to set the @code{specifications} field of the
21892 configuration. Here is an example of a service that polls the Guix repository
21893 and builds the packages from a manifest. Some of the packages are defined in
21894 the @code{"custom-packages"} input, which is the equivalent of
21895 @code{GUIX_PACKAGE_PATH}.
21898 (define %cuirass-specs
21900 '((#:name . "my-manifest")
21901 (#:load-path-inputs . ("guix"))
21902 (#:package-path-inputs . ("custom-packages"))
21903 (#:proc-input . "guix")
21904 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
21905 (#:proc . cuirass-jobs)
21906 (#:proc-args . ((subset . "manifests")
21907 (systems . ("x86_64-linux"))
21908 (manifests . (("config" . "guix/manifest.scm")))))
21909 (#:inputs . (((#:name . "guix")
21910 (#:url . "git://git.savannah.gnu.org/guix.git")
21911 (#:load-path . ".")
21912 (#:branch . "master")
21913 (#:no-compile? . #t))
21914 ((#:name . "config")
21915 (#:url . "https://git.example.org/config.git")
21916 (#:load-path . ".")
21917 (#:branch . "master")
21918 (#:no-compile? . #t))
21919 ((#:name . "custom-packages")
21920 (#:url . "https://git.example.org/custom-packages.git")
21921 (#:load-path . ".")
21922 (#:branch . "master")
21923 (#:no-compile? . #t)))))))
21925 (service cuirass-service-type
21926 (cuirass-configuration
21927 (specifications %cuirass-specs)))
21930 While information related to build jobs is located directly in the
21931 specifications, global settings for the @command{cuirass} process are
21932 accessible in other @code{cuirass-configuration} fields.
21934 @deftp {Data Type} cuirass-configuration
21935 Data type representing the configuration of Cuirass.
21938 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
21939 Location of the log file.
21941 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
21942 Location of the log file used by the web interface.
21944 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
21945 Location of the repository cache.
21947 @item @code{user} (default: @code{"cuirass"})
21948 Owner of the @code{cuirass} process.
21950 @item @code{group} (default: @code{"cuirass"})
21951 Owner's group of the @code{cuirass} process.
21953 @item @code{interval} (default: @code{60})
21954 Number of seconds between the poll of the repositories followed by the
21957 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
21958 Location of sqlite database which contains the build results and previously
21959 added specifications.
21961 @item @code{ttl} (default: @code{(* 30 24 3600)})
21962 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
21963 are registered for build results. This means that build results are protected
21964 from garbage collection for at least @var{ttl} seconds.
21966 @item @code{port} (default: @code{8081})
21967 Port number used by the HTTP server.
21969 @item @code{host} (default: @code{"localhost"})
21970 Listen on the network interface for @var{host}. The default is to
21971 accept connections from localhost.
21973 @item @code{specifications} (default: @code{#~'()})
21974 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
21975 where a specification is an association list
21976 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
21977 keys are keywords (@code{#:keyword-example}) as shown in the example
21980 @item @code{use-substitutes?} (default: @code{#f})
21981 This allows using substitutes to avoid building every dependencies of a job
21984 @item @code{one-shot?} (default: @code{#f})
21985 Only evaluate specifications and build derivations once.
21987 @item @code{fallback?} (default: @code{#f})
21988 When substituting a pre-built binary fails, fall back to building
21991 @item @code{cuirass} (default: @code{cuirass})
21992 The Cuirass package to use.
21996 @node Power Management Services
21997 @subsection Power Management Services
22000 @cindex power management with TLP
22001 @subsubheading TLP daemon
22003 The @code{(gnu services pm)} module provides a Guix service definition
22004 for the Linux power management tool TLP.
22006 TLP enables various powersaving modes in userspace and kernel.
22007 Contrary to @code{upower-service}, it is not a passive,
22008 monitoring tool, as it will apply custom settings each time a new power
22009 source is detected. More information can be found at
22010 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
22012 @deffn {Scheme Variable} tlp-service-type
22013 The service type for the TLP tool. Its value should be a valid
22014 TLP configuration (see below). To use the default settings, simply
22017 (service tlp-service-type)
22021 By default TLP does not need much configuration but most TLP parameters
22022 can be tweaked using @code{tlp-configuration}.
22024 Each parameter definition is preceded by its type; for example,
22025 @samp{boolean foo} indicates that the @code{foo} parameter
22026 should be specified as a boolean. Types starting with
22027 @code{maybe-} denote parameters that won't show up in TLP config file
22028 when their value is @code{'disabled}.
22030 @c The following documentation was initially generated by
22031 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
22032 @c documentation is better, so we shouldn't hesitate to edit below as
22033 @c needed. However if the change you want to make to this documentation
22034 @c can be done in an automated way, it's probably easier to change
22035 @c (generate-documentation) than to make it below and have to deal with
22036 @c the churn as TLP updates.
22038 Available @code{tlp-configuration} fields are:
22040 @deftypevr {@code{tlp-configuration} parameter} package tlp
22045 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
22046 Set to true if you wish to enable TLP.
22048 Defaults to @samp{#t}.
22052 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
22053 Default mode when no power supply can be detected. Alternatives are AC
22056 Defaults to @samp{"AC"}.
22060 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
22061 Number of seconds Linux kernel has to wait after the disk goes idle,
22062 before syncing on AC.
22064 Defaults to @samp{0}.
22068 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
22069 Same as @code{disk-idle-ac} but on BAT mode.
22071 Defaults to @samp{2}.
22075 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
22076 Dirty pages flushing periodicity, expressed in seconds.
22078 Defaults to @samp{15}.
22082 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
22083 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
22085 Defaults to @samp{60}.
22089 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
22090 CPU frequency scaling governor on AC mode. With intel_pstate driver,
22091 alternatives are powersave and performance. With acpi-cpufreq driver,
22092 alternatives are ondemand, powersave, performance and conservative.
22094 Defaults to @samp{disabled}.
22098 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
22099 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
22101 Defaults to @samp{disabled}.
22105 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
22106 Set the min available frequency for the scaling governor on AC.
22108 Defaults to @samp{disabled}.
22112 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
22113 Set the max available frequency for the scaling governor on AC.
22115 Defaults to @samp{disabled}.
22119 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
22120 Set the min available frequency for the scaling governor on BAT.
22122 Defaults to @samp{disabled}.
22126 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
22127 Set the max available frequency for the scaling governor on BAT.
22129 Defaults to @samp{disabled}.
22133 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
22134 Limit the min P-state to control the power dissipation of the CPU, in AC
22135 mode. Values are stated as a percentage of the available performance.
22137 Defaults to @samp{disabled}.
22141 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
22142 Limit the max P-state to control the power dissipation of the CPU, in AC
22143 mode. Values are stated as a percentage of the available performance.
22145 Defaults to @samp{disabled}.
22149 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
22150 Same as @code{cpu-min-perf-on-ac} on BAT mode.
22152 Defaults to @samp{disabled}.
22156 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
22157 Same as @code{cpu-max-perf-on-ac} on BAT mode.
22159 Defaults to @samp{disabled}.
22163 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
22164 Enable CPU turbo boost feature on AC mode.
22166 Defaults to @samp{disabled}.
22170 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
22171 Same as @code{cpu-boost-on-ac?} on BAT mode.
22173 Defaults to @samp{disabled}.
22177 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
22178 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
22179 used under light load conditions.
22181 Defaults to @samp{#f}.
22185 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
22186 Same as @code{sched-powersave-on-ac?} but on BAT mode.
22188 Defaults to @samp{#t}.
22192 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
22193 Enable Linux kernel NMI watchdog.
22195 Defaults to @samp{#f}.
22199 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
22200 For Linux kernels with PHC patch applied, change CPU voltages. An
22201 example value would be @samp{"F:V F:V F:V F:V"}.
22203 Defaults to @samp{disabled}.
22207 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
22208 Set CPU performance versus energy saving policy on AC. Alternatives are
22209 performance, normal, powersave.
22211 Defaults to @samp{"performance"}.
22215 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
22216 Same as @code{energy-perf-policy-ac} but on BAT mode.
22218 Defaults to @samp{"powersave"}.
22222 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
22227 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
22228 Hard disk advanced power management level.
22232 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
22233 Same as @code{disk-apm-bat} but on BAT mode.
22237 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
22238 Hard disk spin down timeout. One value has to be specified for each
22239 declared hard disk.
22241 Defaults to @samp{disabled}.
22245 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
22246 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
22248 Defaults to @samp{disabled}.
22252 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
22253 Select IO scheduler for disk devices. One value has to be specified for
22254 each declared hard disk. Example alternatives are cfq, deadline and
22257 Defaults to @samp{disabled}.
22261 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
22262 SATA aggressive link power management (ALPM) level. Alternatives are
22263 min_power, medium_power, max_performance.
22265 Defaults to @samp{"max_performance"}.
22269 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
22270 Same as @code{sata-linkpwr-ac} but on BAT mode.
22272 Defaults to @samp{"min_power"}.
22276 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
22277 Exclude specified SATA host devices for link power management.
22279 Defaults to @samp{disabled}.
22283 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
22284 Enable Runtime Power Management for AHCI controller and disks on AC
22287 Defaults to @samp{disabled}.
22291 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
22292 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
22294 Defaults to @samp{disabled}.
22298 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
22299 Seconds of inactivity before disk is suspended.
22301 Defaults to @samp{15}.
22305 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
22306 PCI Express Active State Power Management level. Alternatives are
22307 default, performance, powersave.
22309 Defaults to @samp{"performance"}.
22313 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
22314 Same as @code{pcie-aspm-ac} but on BAT mode.
22316 Defaults to @samp{"powersave"}.
22320 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
22321 Radeon graphics clock speed level. Alternatives are low, mid, high,
22324 Defaults to @samp{"high"}.
22328 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
22329 Same as @code{radeon-power-ac} but on BAT mode.
22331 Defaults to @samp{"low"}.
22335 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
22336 Radeon dynamic power management method (DPM). Alternatives are battery,
22339 Defaults to @samp{"performance"}.
22343 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
22344 Same as @code{radeon-dpm-state-ac} but on BAT mode.
22346 Defaults to @samp{"battery"}.
22350 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
22351 Radeon DPM performance level. Alternatives are auto, low, high.
22353 Defaults to @samp{"auto"}.
22357 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
22358 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
22360 Defaults to @samp{"auto"}.
22364 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
22365 Wifi power saving mode.
22367 Defaults to @samp{#f}.
22371 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
22372 Same as @code{wifi-power-ac?} but on BAT mode.
22374 Defaults to @samp{#t}.
22378 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
22379 Disable wake on LAN.
22381 Defaults to @samp{#t}.
22385 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
22386 Timeout duration in seconds before activating audio power saving on
22387 Intel HDA and AC97 devices. A value of 0 disables power saving.
22389 Defaults to @samp{0}.
22393 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
22394 Same as @code{sound-powersave-ac} but on BAT mode.
22396 Defaults to @samp{1}.
22400 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
22401 Disable controller in powersaving mode on Intel HDA devices.
22403 Defaults to @samp{#t}.
22407 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
22408 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
22409 powered on again by releasing (and reinserting) the eject lever or by
22410 pressing the disc eject button on newer models.
22412 Defaults to @samp{#f}.
22416 @deftypevr {@code{tlp-configuration} parameter} string bay-device
22417 Name of the optical drive device to power off.
22419 Defaults to @samp{"sr0"}.
22423 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
22424 Runtime Power Management for PCI(e) bus devices. Alternatives are on
22427 Defaults to @samp{"on"}.
22431 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
22432 Same as @code{runtime-pm-ac} but on BAT mode.
22434 Defaults to @samp{"auto"}.
22438 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
22439 Runtime Power Management for all PCI(e) bus devices, except blacklisted
22442 Defaults to @samp{#t}.
22446 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
22447 Exclude specified PCI(e) device addresses from Runtime Power Management.
22449 Defaults to @samp{disabled}.
22453 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
22454 Exclude PCI(e) devices assigned to the specified drivers from Runtime
22459 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
22460 Enable USB autosuspend feature.
22462 Defaults to @samp{#t}.
22466 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
22467 Exclude specified devices from USB autosuspend.
22469 Defaults to @samp{disabled}.
22473 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
22474 Exclude WWAN devices from USB autosuspend.
22476 Defaults to @samp{#t}.
22480 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
22481 Include specified devices into USB autosuspend, even if they are already
22482 excluded by the driver or via @code{usb-blacklist-wwan?}.
22484 Defaults to @samp{disabled}.
22488 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
22489 Enable USB autosuspend before shutdown.
22491 Defaults to @samp{disabled}.
22495 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
22496 Restore radio device state (bluetooth, wifi, wwan) from previous
22497 shutdown on system startup.
22499 Defaults to @samp{#f}.
22504 @cindex CPU frequency scaling with thermald
22505 @subsubheading Thermald daemon
22507 The @code{(gnu services pm)} module provides an interface to
22508 thermald, a CPU frequency scaling service which helps prevent overheating.
22510 @defvr {Scheme Variable} thermald-service-type
22511 This is the service type for
22512 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
22513 Thermal Daemon, which is responsible for controlling the thermal state
22514 of processors and preventing overheating.
22517 @deftp {Data Type} thermald-configuration
22518 Data type representing the configuration of @code{thermald-service-type}.
22521 @item @code{ignore-cpuid-check?} (default: @code{#f})
22522 Ignore cpuid check for supported CPU models.
22524 @item @code{thermald} (default: @var{thermald})
22525 Package object of thermald.
22530 @node Audio Services
22531 @subsection Audio Services
22533 The @code{(gnu services audio)} module provides a service to start MPD
22534 (the Music Player Daemon).
22537 @subsubheading Music Player Daemon
22539 The Music Player Daemon (MPD) is a service that can play music while
22540 being controlled from the local machine or over the network by a variety
22543 The following example shows how one might run @code{mpd} as user
22544 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
22547 (service mpd-service-type
22553 @defvr {Scheme Variable} mpd-service-type
22554 The service type for @command{mpd}
22557 @deftp {Data Type} mpd-configuration
22558 Data type representing the configuration of @command{mpd}.
22561 @item @code{user} (default: @code{"mpd"})
22562 The user to run mpd as.
22564 @item @code{music-dir} (default: @code{"~/Music"})
22565 The directory to scan for music files.
22567 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
22568 The directory to store playlists.
22570 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
22571 The location of the music database.
22573 @item @code{state-file} (default: @code{"~/.mpd/state"})
22574 The location of the file that stores current MPD's state.
22576 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
22577 The location of the sticker database.
22579 @item @code{port} (default: @code{"6600"})
22580 The port to run mpd on.
22582 @item @code{address} (default: @code{"any"})
22583 The address that mpd will bind to. To use a Unix domain socket,
22584 an absolute path can be specified here.
22586 @item @code{outputs} (default: @code{"(list (mpd-output))"})
22587 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
22592 @deftp {Data Type} mpd-output
22593 Data type representing an @command{mpd} audio output.
22596 @item @code{name} (default: @code{"MPD"})
22597 The name of the audio output.
22599 @item @code{type} (default: @code{"pulse"})
22600 The type of audio output.
22602 @item @code{enabled?} (default: @code{#t})
22603 Specifies whether this audio output is enabled when MPD is started. By
22604 default, all audio outputs are enabled. This is just the default
22605 setting when there is no state file; with a state file, the previous
22608 @item @code{tags?} (default: @code{#t})
22609 If set to @code{#f}, then MPD will not send tags to this output. This
22610 is only useful for output plugins that can receive tags, for example the
22611 @code{httpd} output plugin.
22613 @item @code{always-on?} (default: @code{#f})
22614 If set to @code{#t}, then MPD attempts to keep this audio output always
22615 open. This may be useful for streaming servers, when you don’t want to
22616 disconnect all listeners even when playback is accidentally stopped.
22618 @item @code{mixer-type}
22619 This field accepts a symbol that specifies which mixer should be used
22620 for this audio output: the @code{hardware} mixer, the @code{software}
22621 mixer, the @code{null} mixer (allows setting the volume, but with no
22622 effect; this can be used as a trick to implement an external mixer
22623 External Mixer) or no mixer (@code{none}).
22625 @item @code{extra-options} (default: @code{'()"})
22626 An association list of option symbols to string values to be appended to
22627 the audio output configuration.
22632 The following example shows a configuration of @code{mpd} that provides
22633 an HTTP audio streaming output.
22636 (service mpd-service-type
22644 `((encoder . "vorbis")
22645 (port . "8080"))))))))
22649 @node Virtualization Services
22650 @subsection Virtualization services
22652 The @code{(gnu services virtualization)} module provides services for
22653 the libvirt and virtlog daemons, as well as other virtualization-related
22656 @subsubheading Libvirt daemon
22657 @code{libvirtd} is the server side daemon component of the libvirt
22658 virtualization management system. This daemon runs on host servers
22659 and performs required management tasks for virtualized guests.
22661 @deffn {Scheme Variable} libvirt-service-type
22662 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
22663 Its value must be a @code{libvirt-configuration}.
22666 (service libvirt-service-type
22667 (libvirt-configuration
22668 (unix-sock-group "libvirt")
22669 (tls-port "16555")))
22673 @c Auto-generated with (generate-libvirt-documentation)
22674 Available @code{libvirt-configuration} fields are:
22676 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
22681 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
22682 Flag listening for secure TLS connections on the public TCP/IP port.
22683 must set @code{listen} for this to have any effect.
22685 It is necessary to setup a CA and issue server certificates before using
22688 Defaults to @samp{#t}.
22692 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
22693 Listen for unencrypted TCP connections on the public TCP/IP port. must
22694 set @code{listen} for this to have any effect.
22696 Using the TCP socket requires SASL authentication by default. Only SASL
22697 mechanisms which support data encryption are allowed. This is
22698 DIGEST_MD5 and GSSAPI (Kerberos5)
22700 Defaults to @samp{#f}.
22704 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
22705 Port for accepting secure TLS connections This can be a port number, or
22708 Defaults to @samp{"16514"}.
22712 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
22713 Port for accepting insecure TCP connections This can be a port number,
22716 Defaults to @samp{"16509"}.
22720 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
22721 IP address or hostname used for client connections.
22723 Defaults to @samp{"0.0.0.0"}.
22727 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
22728 Flag toggling mDNS advertisement of the libvirt service.
22730 Alternatively can disable for all services on a host by stopping the
22733 Defaults to @samp{#f}.
22737 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
22738 Default mDNS advertisement name. This must be unique on the immediate
22741 Defaults to @samp{"Virtualization Host <hostname>"}.
22745 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
22746 UNIX domain socket group ownership. This can be used to allow a
22747 'trusted' set of users access to management capabilities without
22750 Defaults to @samp{"root"}.
22754 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
22755 UNIX socket permissions for the R/O socket. This is used for monitoring
22758 Defaults to @samp{"0777"}.
22762 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
22763 UNIX socket permissions for the R/W socket. Default allows only root.
22764 If PolicyKit is enabled on the socket, the default will change to allow
22765 everyone (eg, 0777)
22767 Defaults to @samp{"0770"}.
22771 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
22772 UNIX socket permissions for the admin socket. Default allows only owner
22773 (root), do not change it unless you are sure to whom you are exposing
22776 Defaults to @samp{"0777"}.
22780 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
22781 The directory in which sockets will be found/created.
22783 Defaults to @samp{"/var/run/libvirt"}.
22787 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
22788 Authentication scheme for UNIX read-only sockets. By default socket
22789 permissions allow anyone to connect
22791 Defaults to @samp{"polkit"}.
22795 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
22796 Authentication scheme for UNIX read-write sockets. By default socket
22797 permissions only allow root. If PolicyKit support was compiled into
22798 libvirt, the default will be to use 'polkit' auth.
22800 Defaults to @samp{"polkit"}.
22804 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
22805 Authentication scheme for TCP sockets. If you don't enable SASL, then
22806 all TCP traffic is cleartext. Don't do this outside of a dev/test
22809 Defaults to @samp{"sasl"}.
22813 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
22814 Authentication scheme for TLS sockets. TLS sockets already have
22815 encryption provided by the TLS layer, and limited authentication is done
22818 It is possible to make use of any SASL authentication mechanism as well,
22819 by using 'sasl' for this option
22821 Defaults to @samp{"none"}.
22825 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
22826 API access control scheme.
22828 By default an authenticated user is allowed access to all APIs. Access
22829 drivers can place restrictions on this.
22831 Defaults to @samp{()}.
22835 @deftypevr {@code{libvirt-configuration} parameter} string key-file
22836 Server key file path. If set to an empty string, then no private key is
22839 Defaults to @samp{""}.
22843 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
22844 Server key file path. If set to an empty string, then no certificate is
22847 Defaults to @samp{""}.
22851 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
22852 Server key file path. If set to an empty string, then no CA certificate
22855 Defaults to @samp{""}.
22859 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
22860 Certificate revocation list path. If set to an empty string, then no
22863 Defaults to @samp{""}.
22867 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
22868 Disable verification of our own server certificates.
22870 When libvirtd starts it performs some sanity checks against its own
22873 Defaults to @samp{#f}.
22877 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
22878 Disable verification of client certificates.
22880 Client certificate verification is the primary authentication mechanism.
22881 Any client which does not present a certificate signed by the CA will be
22884 Defaults to @samp{#f}.
22888 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
22889 Whitelist of allowed x509 Distinguished Name.
22891 Defaults to @samp{()}.
22895 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
22896 Whitelist of allowed SASL usernames. The format for username depends on
22897 the SASL authentication mechanism.
22899 Defaults to @samp{()}.
22903 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
22904 Override the compile time default TLS priority string. The default is
22905 usually "NORMAL" unless overridden at build time. Only set this is it
22906 is desired for libvirt to deviate from the global default settings.
22908 Defaults to @samp{"NORMAL"}.
22912 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
22913 Maximum number of concurrent client connections to allow over all
22916 Defaults to @samp{5000}.
22920 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
22921 Maximum length of queue of connections waiting to be accepted by the
22922 daemon. Note, that some protocols supporting retransmission may obey
22923 this so that a later reattempt at connection succeeds.
22925 Defaults to @samp{1000}.
22929 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
22930 Maximum length of queue of accepted but not yet authenticated clients.
22931 Set this to zero to turn this feature off
22933 Defaults to @samp{20}.
22937 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
22938 Number of workers to start up initially.
22940 Defaults to @samp{5}.
22944 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
22945 Maximum number of worker threads.
22947 If the number of active clients exceeds @code{min-workers}, then more
22948 threads are spawned, up to max_workers limit. Typically you'd want
22949 max_workers to equal maximum number of clients allowed.
22951 Defaults to @samp{20}.
22955 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
22956 Number of priority workers. If all workers from above pool are stuck,
22957 some calls marked as high priority (notably domainDestroy) can be
22958 executed in this pool.
22960 Defaults to @samp{5}.
22964 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
22965 Total global limit on concurrent RPC calls.
22967 Defaults to @samp{20}.
22971 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
22972 Limit on concurrent requests from a single client connection. To avoid
22973 one client monopolizing the server this should be a small fraction of
22974 the global max_requests and max_workers parameter.
22976 Defaults to @samp{5}.
22980 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
22981 Same as @code{min-workers} but for the admin interface.
22983 Defaults to @samp{1}.
22987 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
22988 Same as @code{max-workers} but for the admin interface.
22990 Defaults to @samp{5}.
22994 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
22995 Same as @code{max-clients} but for the admin interface.
22997 Defaults to @samp{5}.
23001 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
23002 Same as @code{max-queued-clients} but for the admin interface.
23004 Defaults to @samp{5}.
23008 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
23009 Same as @code{max-client-requests} but for the admin interface.
23011 Defaults to @samp{5}.
23015 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
23016 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23018 Defaults to @samp{3}.
23022 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
23025 A filter allows to select a different logging level for a given category
23026 of logs The format for a filter is one of:
23037 where @code{name} is a string which is matched against the category
23038 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23039 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23040 be a substring of the full category name, in order to match multiple
23041 similar categories), the optional "+" prefix tells libvirt to log stack
23042 trace for each message matching name, and @code{x} is the minimal level
23043 where matching messages should be logged:
23060 Multiple filters can be defined in a single filters statement, they just
23061 need to be separated by spaces.
23063 Defaults to @samp{"3:remote 4:event"}.
23067 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
23070 An output is one of the places to save logging information. The format
23071 for an output can be:
23075 output goes to stderr
23077 @item x:syslog:name
23078 use syslog for the output and use the given name as the ident
23080 @item x:file:file_path
23081 output to a file, with the given filepath
23084 output to journald logging system
23088 In all case the x prefix is the minimal level, acting as a filter
23105 Multiple outputs can be defined, they just need to be separated by
23108 Defaults to @samp{"3:stderr"}.
23112 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
23113 Allows usage of the auditing subsystem to be altered
23117 0: disable all auditing
23120 1: enable auditing, only if enabled on host
23123 2: enable auditing, and exit if disabled on host.
23127 Defaults to @samp{1}.
23131 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
23132 Send audit messages via libvirt logging infrastructure.
23134 Defaults to @samp{#f}.
23138 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
23139 Host UUID. UUID must not have all digits be the same.
23141 Defaults to @samp{""}.
23145 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
23146 Source to read host UUID.
23150 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
23153 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
23157 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
23160 Defaults to @samp{"smbios"}.
23164 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
23165 A keepalive message is sent to a client after @code{keepalive_interval}
23166 seconds of inactivity to check if the client is still responding. If
23167 set to -1, libvirtd will never send keepalive requests; however clients
23168 can still send them and the daemon will send responses.
23170 Defaults to @samp{5}.
23174 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
23175 Maximum number of keepalive messages that are allowed to be sent to the
23176 client without getting any response before the connection is considered
23179 In other words, the connection is automatically closed approximately
23180 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
23181 the last message received from the client. When @code{keepalive-count}
23182 is set to 0, connections will be automatically closed after
23183 @code{keepalive-interval} seconds of inactivity without sending any
23184 keepalive messages.
23186 Defaults to @samp{5}.
23190 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
23191 Same as above but for admin interface.
23193 Defaults to @samp{5}.
23197 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
23198 Same as above but for admin interface.
23200 Defaults to @samp{5}.
23204 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
23205 Timeout for Open vSwitch calls.
23207 The @code{ovs-vsctl} utility is used for the configuration and its
23208 timeout option is set by default to 5 seconds to avoid potential
23209 infinite waits blocking libvirt.
23211 Defaults to @samp{5}.
23215 @c %end of autogenerated docs
23217 @subsubheading Virtlog daemon
23218 The virtlogd service is a server side daemon component of libvirt that is
23219 used to manage logs from virtual machine consoles.
23221 This daemon is not used directly by libvirt client applications, rather it
23222 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
23223 standalone daemon, the main @code{libvirtd} daemon can be restarted without
23224 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
23225 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
23227 @deffn {Scheme Variable} virtlog-service-type
23228 This is the type of the virtlog daemon.
23229 Its value must be a @code{virtlog-configuration}.
23232 (service virtlog-service-type
23233 (virtlog-configuration
23234 (max-clients 1000)))
23238 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
23239 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23241 Defaults to @samp{3}.
23245 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
23248 A filter allows to select a different logging level for a given category
23249 of logs The format for a filter is one of:
23260 where @code{name} is a string which is matched against the category
23261 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23262 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23263 be a substring of the full category name, in order to match multiple
23264 similar categories), the optional "+" prefix tells libvirt to log stack
23265 trace for each message matching name, and @code{x} is the minimal level
23266 where matching messages should be logged:
23283 Multiple filters can be defined in a single filters statement, they just
23284 need to be separated by spaces.
23286 Defaults to @samp{"3:remote 4:event"}.
23290 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
23293 An output is one of the places to save logging information The format
23294 for an output can be:
23298 output goes to stderr
23300 @item x:syslog:name
23301 use syslog for the output and use the given name as the ident
23303 @item x:file:file_path
23304 output to a file, with the given filepath
23307 output to journald logging system
23311 In all case the x prefix is the minimal level, acting as a filter
23328 Multiple outputs can be defined, they just need to be separated by
23331 Defaults to @samp{"3:stderr"}.
23335 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
23336 Maximum number of concurrent client connections to allow over all
23339 Defaults to @samp{1024}.
23343 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
23344 Maximum file size before rolling over.
23346 Defaults to @samp{2MB}
23350 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
23351 Maximum number of backup files to keep.
23353 Defaults to @samp{3}
23357 @subsubheading Transparent Emulation with QEMU
23360 @cindex @code{binfmt_misc}
23361 @code{qemu-binfmt-service-type} provides support for transparent
23362 emulation of program binaries built for different architectures---e.g.,
23363 it allows you to transparently execute an ARMv7 program on an x86_64
23364 machine. It achieves this by combining the @uref{https://www.qemu.org,
23365 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
23367 @defvr {Scheme Variable} qemu-binfmt-service-type
23368 This is the type of the QEMU/binfmt service for transparent emulation.
23369 Its value must be a @code{qemu-binfmt-configuration} object, which
23370 specifies the QEMU package to use as well as the architecture we want to
23374 (service qemu-binfmt-service-type
23375 (qemu-binfmt-configuration
23376 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
23379 In this example, we enable transparent emulation for the ARM and aarch64
23380 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
23381 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
23382 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
23385 @deftp {Data Type} qemu-binfmt-configuration
23386 This is the configuration for the @code{qemu-binfmt} service.
23389 @item @code{platforms} (default: @code{'()})
23390 The list of emulated QEMU platforms. Each item must be a @dfn{platform
23391 object} as returned by @code{lookup-qemu-platforms} (see below).
23393 @item @code{guix-support?} (default: @code{#f})
23394 When it is true, QEMU and all its dependencies are added to the build
23395 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
23396 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
23397 handlers to be used within the build environment, which in turn means
23398 that you can transparently build programs for another architecture.
23400 For example, let's suppose you're on an x86_64 machine and you have this
23404 (service qemu-binfmt-service-type
23405 (qemu-binfmt-configuration
23406 (platforms (lookup-qemu-platforms "arm"))
23407 (guix-support? #t)))
23413 guix build -s armhf-linux inkscape
23417 and it will build Inkscape for ARMv7 @emph{as if it were a native
23418 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
23419 if you'd like to test a package build for an architecture you don't have
23422 @item @code{qemu} (default: @code{qemu})
23423 The QEMU package to use.
23427 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
23428 Return the list of QEMU platform objects corresponding to
23429 @var{platforms}@dots{}. @var{platforms} must be a list of strings
23430 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
23431 @code{"mips64el"}, and so on.
23434 @deffn {Scheme Procedure} qemu-platform? @var{obj}
23435 Return true if @var{obj} is a platform object.
23438 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
23439 Return the name of @var{platform}---a string such as @code{"arm"}.
23442 @node Version Control Services
23443 @subsection Version Control Services
23445 The @code{(gnu services version-control)} module provides a service to
23446 allow remote access to local Git repositories. There are three options:
23447 the @code{git-daemon-service}, which provides access to repositories via
23448 the @code{git://} unsecured TCP-based protocol, extending the
23449 @code{nginx} web server to proxy some requests to
23450 @code{git-http-backend}, or providing a web interface with
23451 @code{cgit-service-type}.
23453 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
23455 Return a service that runs @command{git daemon}, a simple TCP server to
23456 expose repositories over the Git protocol for anonymous access.
23458 The optional @var{config} argument should be a
23459 @code{<git-daemon-configuration>} object, by default it allows read-only
23460 access to exported@footnote{By creating the magic file
23461 "git-daemon-export-ok" in the repository directory.} repositories under
23466 @deftp {Data Type} git-daemon-configuration
23467 Data type representing the configuration for @code{git-daemon-service}.
23470 @item @code{package} (default: @var{git})
23471 Package object of the Git distributed version control system.
23473 @item @code{export-all?} (default: @var{#f})
23474 Whether to allow access for all Git repositories, even if they do not
23475 have the @file{git-daemon-export-ok} file.
23477 @item @code{base-path} (default: @file{/srv/git})
23478 Whether to remap all the path requests as relative to the given path.
23479 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
23480 then if you later try to pull @code{git://example.com/hello.git}, git
23481 daemon will interpret the path as @code{/srv/git/hello.git}.
23483 @item @code{user-path} (default: @var{#f})
23484 Whether to allow @code{~user} notation to be used in requests. When
23485 specified with empty string, requests to @code{git://host/~alice/foo} is
23486 taken as a request to access @code{foo} repository in the home directory
23487 of user @code{alice}. If @var{(user-path "path")} is specified, the
23488 same request is taken as a request to access @code{path/foo} repository
23489 in the home directory of user @code{alice}.
23491 @item @code{listen} (default: @var{'()})
23492 Whether to listen on specific IP addresses or hostnames, defaults to
23495 @item @code{port} (default: @var{#f})
23496 Whether to listen on an alternative port, which defaults to 9418.
23498 @item @code{whitelist} (default: @var{'()})
23499 If not empty, only allow access to this list of directories.
23501 @item @code{extra-options} (default: @var{'()})
23502 Extra options will be passed to @code{git daemon}, please run
23503 @command{man git-daemon} for more information.
23508 The @code{git://} protocol lacks authentication. When you pull from a
23509 repository fetched via @code{git://}, you don't know whether the data you
23510 receive was modified or is even coming from the specified host, and your
23511 connection is subject to eavesdropping. It's better to use an authenticated
23512 and encrypted transport, such as @code{https}. Although Git allows you
23513 to serve repositories using unsophisticated file-based web servers,
23514 there is a faster protocol implemented by the @code{git-http-backend}
23515 program. This program is the back-end of a proper Git web service. It
23516 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
23517 on running the necessary @code{fcgiwrap} daemon.
23519 Guix has a separate configuration data type for serving Git repositories
23522 @deftp {Data Type} git-http-configuration
23523 Data type representing the configuration for @code{git-http-service}.
23526 @item @code{package} (default: @var{git})
23527 Package object of the Git distributed version control system.
23529 @item @code{git-root} (default: @file{/srv/git})
23530 Directory containing the Git repositories to expose to the world.
23532 @item @code{export-all?} (default: @var{#f})
23533 Whether to expose access for all Git repositories in @var{git-root},
23534 even if they do not have the @file{git-daemon-export-ok} file.
23536 @item @code{uri-path} (default: @file{/git/})
23537 Path prefix for Git access. With the default @code{/git/} prefix, this
23538 will map @code{http://@var{server}/git/@var{repo}.git} to
23539 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
23540 with this prefix are not passed on to this Git instance.
23542 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
23543 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
23548 There is no @code{git-http-service-type}, currently; instead you can
23549 create an @code{nginx-location-configuration} from a
23550 @code{git-http-configuration} and then add that location to a web
23553 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
23554 [config=(git-http-configuration)]
23555 Compute an @code{nginx-location-configuration} that corresponds to the
23556 given Git http configuration. An example nginx service definition to
23557 serve the default @file{/srv/git} over HTTPS might be:
23560 (service nginx-service-type
23561 (nginx-configuration
23564 (nginx-server-configuration
23565 (listen '("443 ssl"))
23566 (server-name "git.my-host.org")
23568 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
23569 (ssl-certificate-key
23570 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
23573 (git-http-nginx-location-configuration
23574 (git-http-configuration (uri-path "/"))))))))))
23577 This example assumes that you are using Let's Encrypt to get your TLS
23578 certificate. @xref{Certificate Services}. The default @code{certbot}
23579 service will redirect all HTTP traffic on @code{git.my-host.org} to
23580 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
23581 system services. @xref{Web Services}.
23584 @subsubheading Cgit Service
23586 @cindex Cgit service
23587 @cindex Git, web interface
23588 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
23589 repositories written in C.
23591 The following example will configure the service with default values.
23592 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
23595 (service cgit-service-type)
23598 The @code{file-object} type designates either a file-like object
23599 (@pxref{G-Expressions, file-like objects}) or a string.
23601 @c %start of fragment
23603 Available @code{cgit-configuration} fields are:
23605 @deftypevr {@code{cgit-configuration} parameter} package package
23610 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
23611 NGINX configuration.
23615 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
23616 Specifies a command which will be invoked to format the content of about
23617 pages (both top-level and for each repository).
23619 Defaults to @samp{""}.
23623 @deftypevr {@code{cgit-configuration} parameter} string agefile
23624 Specifies a path, relative to each repository path, which can be used to
23625 specify the date and time of the youngest commit in the repository.
23627 Defaults to @samp{""}.
23631 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
23632 Specifies a command that will be invoked for authenticating repository
23635 Defaults to @samp{""}.
23639 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
23640 Flag which, when set to @samp{age}, enables date ordering in the branch
23641 ref list, and when set @samp{name} enables ordering by branch name.
23643 Defaults to @samp{"name"}.
23647 @deftypevr {@code{cgit-configuration} parameter} string cache-root
23648 Path used to store the cgit cache entries.
23650 Defaults to @samp{"/var/cache/cgit"}.
23654 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
23655 Number which specifies the time-to-live, in minutes, for the cached
23656 version of repository pages accessed with a fixed SHA1.
23658 Defaults to @samp{-1}.
23662 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
23663 Number which specifies the time-to-live, in minutes, for the cached
23664 version of repository pages accessed without a fixed SHA1.
23666 Defaults to @samp{5}.
23670 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
23671 Number which specifies the time-to-live, in minutes, for the cached
23672 version of the repository summary page.
23674 Defaults to @samp{5}.
23678 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
23679 Number which specifies the time-to-live, in minutes, for the cached
23680 version of the repository index page.
23682 Defaults to @samp{5}.
23686 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
23687 Number which specifies the time-to-live, in minutes, for the result of
23688 scanning a path for Git repositories.
23690 Defaults to @samp{15}.
23694 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
23695 Number which specifies the time-to-live, in minutes, for the cached
23696 version of the repository about page.
23698 Defaults to @samp{15}.
23702 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
23703 Number which specifies the time-to-live, in minutes, for the cached
23704 version of snapshots.
23706 Defaults to @samp{5}.
23710 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
23711 The maximum number of entries in the cgit cache. When set to @samp{0},
23712 caching is disabled.
23714 Defaults to @samp{0}.
23718 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
23719 Sort items in the repo list case sensitively.
23721 Defaults to @samp{#t}.
23725 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
23726 List of common prefixes which, when combined with a repository URL,
23727 generates valid clone URLs for the repository.
23729 Defaults to @samp{()}.
23733 @deftypevr {@code{cgit-configuration} parameter} list clone-url
23734 List of @code{clone-url} templates.
23736 Defaults to @samp{()}.
23740 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
23741 Command which will be invoked to format commit messages.
23743 Defaults to @samp{""}.
23747 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
23748 Flag which, when set to @samp{date}, enables strict date ordering in the
23749 commit log, and when set to @samp{topo} enables strict topological
23752 Defaults to @samp{"git log"}.
23756 @deftypevr {@code{cgit-configuration} parameter} file-object css
23757 URL which specifies the css document to include in all cgit pages.
23759 Defaults to @samp{"/share/cgit/cgit.css"}.
23763 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
23764 Specifies a command which will be invoked to format names and email
23765 address of committers, authors, and taggers, as represented in various
23766 places throughout the cgit interface.
23768 Defaults to @samp{""}.
23772 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
23773 Flag which, when set to @samp{#t}, will make cgit generate a HTML
23774 fragment suitable for embedding in other HTML pages.
23776 Defaults to @samp{#f}.
23780 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
23781 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
23782 commit history graph to the left of the commit messages in the
23783 repository log page.
23785 Defaults to @samp{#f}.
23789 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
23790 Flag which, when set to @samp{#t}, allows all filter settings to be
23791 overridden in repository-specific cgitrc files.
23793 Defaults to @samp{#f}.
23797 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
23798 Flag which, when set to @samp{#t}, allows users to follow a file in the
23801 Defaults to @samp{#f}.
23805 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
23806 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
23809 Defaults to @samp{#t}.
23813 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
23814 Flag which, when set to @samp{#t}, will make cgit generate extra links
23815 "summary", "commit", "tree" for each repo in the repository index.
23817 Defaults to @samp{#f}.
23821 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
23822 Flag which, when set to @samp{#t}, will make cgit display the owner of
23823 each repo in the repository index.
23825 Defaults to @samp{#t}.
23829 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
23830 Flag which, when set to @samp{#t}, will make cgit print the number of
23831 modified files for each commit on the repository log page.
23833 Defaults to @samp{#f}.
23837 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
23838 Flag which, when set to @samp{#t}, will make cgit print the number of
23839 added and removed lines for each commit on the repository log page.
23841 Defaults to @samp{#f}.
23845 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
23846 Flag which, when set to @code{#t}, will make cgit display remote
23847 branches in the summary and refs views.
23849 Defaults to @samp{#f}.
23853 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
23854 Flag which, when set to @code{1}, will make cgit use the subject of the
23855 parent commit as link text when generating links to parent commits in
23858 Defaults to @samp{#f}.
23862 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
23863 Flag which, when set to @samp{#t}, will make cgit use the subject of the
23864 parent commit as link text when generating links to parent commits in
23867 Defaults to @samp{#f}.
23871 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
23872 Flag which, when set to @samp{#t}, will make cgit generate linenumber
23873 links for plaintext blobs printed in the tree view.
23875 Defaults to @samp{#t}.
23879 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
23880 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
23881 set any repo specific settings.
23883 Defaults to @samp{#f}.
23887 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
23888 URL used as link to a shortcut icon for cgit.
23890 Defaults to @samp{"/favicon.ico"}.
23894 @deftypevr {@code{cgit-configuration} parameter} string footer
23895 The content of the file specified with this option will be included
23896 verbatim at the bottom of all pages (i.e.@: it replaces the standard
23897 "generated by..."@: message).
23899 Defaults to @samp{""}.
23903 @deftypevr {@code{cgit-configuration} parameter} string head-include
23904 The content of the file specified with this option will be included
23905 verbatim in the HTML HEAD section on all pages.
23907 Defaults to @samp{""}.
23911 @deftypevr {@code{cgit-configuration} parameter} string header
23912 The content of the file specified with this option will be included
23913 verbatim at the top of all pages.
23915 Defaults to @samp{""}.
23919 @deftypevr {@code{cgit-configuration} parameter} file-object include
23920 Name of a configfile to include before the rest of the current config-
23923 Defaults to @samp{""}.
23927 @deftypevr {@code{cgit-configuration} parameter} string index-header
23928 The content of the file specified with this option will be included
23929 verbatim above the repository index.
23931 Defaults to @samp{""}.
23935 @deftypevr {@code{cgit-configuration} parameter} string index-info
23936 The content of the file specified with this option will be included
23937 verbatim below the heading on the repository index page.
23939 Defaults to @samp{""}.
23943 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
23944 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
23945 in the servers timezone.
23947 Defaults to @samp{#f}.
23951 @deftypevr {@code{cgit-configuration} parameter} file-object logo
23952 URL which specifies the source of an image which will be used as a logo
23955 Defaults to @samp{"/share/cgit/cgit.png"}.
23959 @deftypevr {@code{cgit-configuration} parameter} string logo-link
23960 URL loaded when clicking on the cgit logo image.
23962 Defaults to @samp{""}.
23966 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
23967 Command which will be invoked to format the Owner column of the main
23970 Defaults to @samp{""}.
23974 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
23975 Number of items to display in atom feeds view.
23977 Defaults to @samp{10}.
23981 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
23982 Number of entries to list per page in "log" view.
23984 Defaults to @samp{50}.
23988 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
23989 Number of commit message characters to display in "log" view.
23991 Defaults to @samp{80}.
23995 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
23996 Specifies the number of entries to list per page on the repository index
23999 Defaults to @samp{50}.
24003 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
24004 Specifies the maximum number of repo description characters to display
24005 on the repository index page.
24007 Defaults to @samp{80}.
24011 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
24012 Specifies the maximum size of a blob to display HTML for in KBytes.
24014 Defaults to @samp{0}.
24018 @deftypevr {@code{cgit-configuration} parameter} string max-stats
24019 Maximum statistics period. Valid values are @samp{week},@samp{month},
24020 @samp{quarter} and @samp{year}.
24022 Defaults to @samp{""}.
24026 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
24027 Mimetype for the specified filename extension.
24029 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
24030 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
24031 "image/png") (svg "image/svg+xml"))}.
24035 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
24036 Specifies the file to use for automatic mimetype lookup.
24038 Defaults to @samp{""}.
24042 @deftypevr {@code{cgit-configuration} parameter} string module-link
24043 Text which will be used as the formatstring for a hyperlink when a
24044 submodule is printed in a directory listing.
24046 Defaults to @samp{""}.
24050 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
24051 If set to the value @samp{#t} caching will be disabled.
24053 Defaults to @samp{#f}.
24057 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
24058 If set to @samp{#t} showing full author email addresses will be
24061 Defaults to @samp{#f}.
24065 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
24066 Flag which, when set to @samp{#t}, will make cgit omit the standard
24067 header on all pages.
24069 Defaults to @samp{#f}.
24073 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
24074 A list of subdirectories inside of @code{repository-directory}, relative
24075 to it, that should loaded as Git repositories. An empty list means that
24076 all subdirectories will be loaded.
24078 Defaults to @samp{()}.
24082 @deftypevr {@code{cgit-configuration} parameter} file-object readme
24083 Text which will be used as default value for @code{cgit-repo-readme}.
24085 Defaults to @samp{""}.
24089 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
24090 If set to @code{#t} and @code{repository-directory} is enabled, if any
24091 repositories are found with a suffix of @code{.git}, this suffix will be
24092 removed for the URL and name.
24094 Defaults to @samp{#f}.
24098 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
24099 Maximum number of files to consider when detecting renames.
24101 Defaults to @samp{-1}.
24105 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
24106 The way in which repositories in each section are sorted.
24108 Defaults to @samp{""}.
24112 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
24113 Text used as content for the @code{robots} meta-tag.
24115 Defaults to @samp{("noindex" "nofollow")}.
24119 @deftypevr {@code{cgit-configuration} parameter} string root-desc
24120 Text printed below the heading on the repository index page.
24122 Defaults to @samp{"a fast webinterface for the git dscm"}.
24126 @deftypevr {@code{cgit-configuration} parameter} string root-readme
24127 The content of the file specified with this option will be included
24128 verbatim below thef "about" link on the repository index page.
24130 Defaults to @samp{""}.
24134 @deftypevr {@code{cgit-configuration} parameter} string root-title
24135 Text printed as heading on the repository index page.
24137 Defaults to @samp{""}.
24141 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
24142 If set to @samp{#t} and repository-directory is enabled,
24143 repository-directory will recurse into directories whose name starts
24144 with a period. Otherwise, repository-directory will stay away from such
24145 directories, considered as "hidden". Note that this does not apply to
24146 the ".git" directory in non-bare repos.
24148 Defaults to @samp{#f}.
24152 @deftypevr {@code{cgit-configuration} parameter} list snapshots
24153 Text which specifies the default set of snapshot formats that cgit
24154 generates links for.
24156 Defaults to @samp{()}.
24160 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
24161 Name of the directory to scan for repositories (represents
24164 Defaults to @samp{"/srv/git"}.
24168 @deftypevr {@code{cgit-configuration} parameter} string section
24169 The name of the current repository section - all repositories defined
24170 after this option will inherit the current section name.
24172 Defaults to @samp{""}.
24176 @deftypevr {@code{cgit-configuration} parameter} string section-sort
24177 Flag which, when set to @samp{1}, will sort the sections on the
24178 repository listing by name.
24180 Defaults to @samp{""}.
24184 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
24185 A number which, if defined prior to repository-directory, specifies how
24186 many path elements from each repo path to use as a default section name.
24188 Defaults to @samp{0}.
24192 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
24193 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
24196 Defaults to @samp{#f}.
24200 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
24201 Specifies a command which will be invoked to format plaintext blobs in
24204 Defaults to @samp{""}.
24208 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
24209 Specifies the number of branches to display in the repository "summary"
24212 Defaults to @samp{10}.
24216 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
24217 Specifies the number of log entries to display in the repository
24220 Defaults to @samp{10}.
24224 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
24225 Specifies the number of tags to display in the repository "summary"
24228 Defaults to @samp{10}.
24232 @deftypevr {@code{cgit-configuration} parameter} string strict-export
24233 Filename which, if specified, needs to be present within the repository
24234 for cgit to allow access to that repository.
24236 Defaults to @samp{""}.
24240 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
24241 URL which, if specified, will be used as root for all cgit links.
24243 Defaults to @samp{"/"}.
24247 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
24248 A list of @dfn{cgit-repo} records to use with config.
24250 Defaults to @samp{()}.
24252 Available @code{repository-cgit-configuration} fields are:
24254 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
24255 A mask of snapshot formats for this repo that cgit generates links for,
24256 restricted by the global @code{snapshots} setting.
24258 Defaults to @samp{()}.
24262 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
24263 Override the default @code{source-filter}.
24265 Defaults to @samp{""}.
24269 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
24270 The relative URL used to access the repository.
24272 Defaults to @samp{""}.
24276 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
24277 Override the default @code{about-filter}.
24279 Defaults to @samp{""}.
24283 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
24284 Flag which, when set to @samp{age}, enables date ordering in the branch
24285 ref list, and when set to @samp{name} enables ordering by branch name.
24287 Defaults to @samp{""}.
24291 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
24292 A list of URLs which can be used to clone repo.
24294 Defaults to @samp{()}.
24298 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
24299 Override the default @code{commit-filter}.
24301 Defaults to @samp{""}.
24305 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
24306 Flag which, when set to @samp{date}, enables strict date ordering in the
24307 commit log, and when set to @samp{topo} enables strict topological
24310 Defaults to @samp{""}.
24314 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
24315 The name of the default branch for this repository. If no such branch
24316 exists in the repository, the first branch name (when sorted) is used as
24317 default instead. By default branch pointed to by HEAD, or "master" if
24318 there is no suitable HEAD.
24320 Defaults to @samp{""}.
24324 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
24325 The value to show as repository description.
24327 Defaults to @samp{""}.
24331 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
24332 The value to show as repository homepage.
24334 Defaults to @samp{""}.
24338 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
24339 Override the default @code{email-filter}.
24341 Defaults to @samp{""}.
24345 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
24346 A flag which can be used to disable the global setting
24347 @code{enable-commit-graph?}.
24349 Defaults to @samp{disabled}.
24353 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
24354 A flag which can be used to disable the global setting
24355 @code{enable-log-filecount?}.
24357 Defaults to @samp{disabled}.
24361 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
24362 A flag which can be used to disable the global setting
24363 @code{enable-log-linecount?}.
24365 Defaults to @samp{disabled}.
24369 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
24370 Flag which, when set to @code{#t}, will make cgit display remote
24371 branches in the summary and refs views.
24373 Defaults to @samp{disabled}.
24377 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
24378 A flag which can be used to override the global setting
24379 @code{enable-subject-links?}.
24381 Defaults to @samp{disabled}.
24385 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
24386 A flag which can be used to override the global setting
24387 @code{enable-html-serving?}.
24389 Defaults to @samp{disabled}.
24393 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
24394 Flag which, when set to @code{#t}, hides the repository from the
24397 Defaults to @samp{#f}.
24401 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
24402 Flag which, when set to @samp{#t}, ignores the repository.
24404 Defaults to @samp{#f}.
24408 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
24409 URL which specifies the source of an image which will be used as a logo
24410 on this repo’s pages.
24412 Defaults to @samp{""}.
24416 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
24417 URL loaded when clicking on the cgit logo image.
24419 Defaults to @samp{""}.
24423 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
24424 Override the default @code{owner-filter}.
24426 Defaults to @samp{""}.
24430 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
24431 Text which will be used as the formatstring for a hyperlink when a
24432 submodule is printed in a directory listing. The arguments for the
24433 formatstring are the path and SHA1 of the submodule commit.
24435 Defaults to @samp{""}.
24439 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
24440 Text which will be used as the formatstring for a hyperlink when a
24441 submodule with the specified subdirectory path is printed in a directory
24444 Defaults to @samp{()}.
24448 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
24449 Override the default maximum statistics period.
24451 Defaults to @samp{""}.
24455 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
24456 The value to show as repository name.
24458 Defaults to @samp{""}.
24462 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
24463 A value used to identify the owner of the repository.
24465 Defaults to @samp{""}.
24469 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
24470 An absolute path to the repository directory.
24472 Defaults to @samp{""}.
24476 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
24477 A path (relative to repo) which specifies a file to include verbatim as
24478 the "About" page for this repo.
24480 Defaults to @samp{""}.
24484 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
24485 The name of the current repository section - all repositories defined
24486 after this option will inherit the current section name.
24488 Defaults to @samp{""}.
24492 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
24493 Extra options will be appended to cgitrc file.
24495 Defaults to @samp{()}.
24501 @deftypevr {@code{cgit-configuration} parameter} list extra-options
24502 Extra options will be appended to cgitrc file.
24504 Defaults to @samp{()}.
24509 @c %end of fragment
24511 However, it could be that you just want to get a @code{cgitrc} up and
24512 running. In that case, you can pass an @code{opaque-cgit-configuration}
24513 as a record to @code{cgit-service-type}. As its name indicates, an
24514 opaque configuration does not have easy reflective capabilities.
24516 Available @code{opaque-cgit-configuration} fields are:
24518 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
24522 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
24523 The contents of the @code{cgitrc}, as a string.
24526 For example, if your @code{cgitrc} is just the empty string, you
24527 could instantiate a cgit service like this:
24530 (service cgit-service-type
24531 (opaque-cgit-configuration
24535 @subsubheading Gitolite Service
24537 @cindex Gitolite service
24538 @cindex Git, hosting
24539 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
24540 repositories on a central server.
24542 Gitolite can handle multiple repositories and users, and supports flexible
24543 configuration of the permissions for the users on the repositories.
24545 The following example will configure Gitolite using the default @code{git}
24546 user, and the provided SSH public key.
24549 (service gitolite-service-type
24550 (gitolite-configuration
24551 (admin-pubkey (plain-file
24553 "ssh-rsa AAAA... guix@@example.com"))))
24556 Gitolite is configured through a special admin repository which you can clone,
24557 for example, if you setup Gitolite on @code{example.com}, you would run the
24558 following command to clone the admin repository.
24561 git clone git@@example.com:gitolite-admin
24564 When the Gitolite service is activated, the provided @code{admin-pubkey} will
24565 be inserted in to the @file{keydir} directory in the gitolite-admin
24566 repository. If this results in a change in the repository, it will be
24567 committed using the message ``gitolite setup by GNU Guix''.
24569 @deftp {Data Type} gitolite-configuration
24570 Data type representing the configuration for @code{gitolite-service-type}.
24573 @item @code{package} (default: @var{gitolite})
24574 Gitolite package to use.
24576 @item @code{user} (default: @var{git})
24577 User to use for Gitolite. This will be user that you use when accessing
24580 @item @code{group} (default: @var{git})
24581 Group to use for Gitolite.
24583 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
24584 Directory in which to store the Gitolite configuration and repositories.
24586 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
24587 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
24588 representing the configuration for Gitolite.
24590 @item @code{admin-pubkey} (default: @var{#f})
24591 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
24592 setup Gitolite. This will be inserted in to the @file{keydir} directory
24593 within the gitolite-admin repository.
24595 To specify the SSH key as a string, use the @code{plain-file} function.
24598 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
24604 @deftp {Data Type} gitolite-rc-file
24605 Data type representing the Gitolite RC file.
24608 @item @code{umask} (default: @code{#o0077})
24609 This controls the permissions Gitolite sets on the repositories and their
24612 A value like @code{#o0027} will give read access to the group used by Gitolite
24613 (by default: @code{git}). This is necessary when using Gitolite with software
24614 like cgit or gitweb.
24616 @item @code{git-config-keys} (default: @code{""})
24617 Gitolite allows you to set git config values using the "config" keyword. This
24618 setting allows control over the config keys to accept.
24620 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
24621 Set the role names allowed to be used by users running the perms command.
24623 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
24624 This setting controls the commands and features to enable within Gitolite.
24630 @node Game Services
24631 @subsection Game Services
24633 @subsubheading The Battle for Wesnoth Service
24635 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
24636 based tactical strategy game, with several single player campaigns, and
24637 multiplayer games (both networked and local).
24639 @defvar {Scheme Variable} wesnothd-service-type
24640 Service type for the wesnothd service. Its value must be a
24641 @code{wesnothd-configuration} object. To run wesnothd in the default
24642 configuration, instantiate it as:
24645 (service wesnothd-service-type)
24649 @deftp {Data Type} wesnothd-configuration
24650 Data type representing the configuration of @command{wesnothd}.
24653 @item @code{package} (default: @code{wesnoth-server})
24654 The wesnoth server package to use.
24656 @item @code{port} (default: @code{15000})
24657 The port to bind the server to.
24662 @node PAM Mount Service
24663 @subsection PAM Mount Service
24666 The @code{(gnu services pam-mount)} module provides a service allowing
24667 users to mount volumes when they log in. It should be able to mount any
24668 volume format supported by the system.
24670 @defvar {Scheme Variable} pam-mount-service-type
24671 Service type for PAM Mount support.
24674 @deftp {Data Type} pam-mount-configuration
24675 Data type representing the configuration of PAM Mount.
24677 It takes the following parameters:
24681 The configuration rules that will be used to generate
24682 @file{/etc/security/pam_mount.conf.xml}.
24684 The configuration rules are SXML elements, and the the default ones
24685 don't mount anything for anyone at login:
24688 `((debug (@@ (enable "0")))
24689 (mntoptions (@@ (allow ,(string-join
24690 '("nosuid" "nodev" "loop"
24691 "encryption" "fsck" "nonempty"
24692 "allow_root" "allow_other")
24694 (mntoptions (@@ (require "nosuid,nodev")))
24695 (logout (@@ (wait "0")
24699 (mkmountpoint (@@ (enable "1")
24703 Some @code{volume} elements must be added to automatically mount volumes
24704 at login. Here's an example allowing the user @code{alice} to mount her
24705 encrypted @code{HOME} directory and allowing the user @code{bob} to mount
24706 the partition where he stores his data:
24709 (define pam-mount-rules
24710 `((debug (@@ (enable "0")))
24711 (volume (@@ (user "alice")
24714 (mountpoint "/home/alice")))
24715 (volume (@@ (user "bob")
24718 (mountpoint "/home/bob/data")
24719 (options "defaults,autodefrag,compress")))
24720 (mntoptions (@@ (allow ,(string-join
24721 '("nosuid" "nodev" "loop"
24722 "encryption" "fsck" "nonempty"
24723 "allow_root" "allow_other")
24725 (mntoptions (@@ (require "nosuid,nodev")))
24726 (logout (@@ (wait "0")
24730 (mkmountpoint (@@ (enable "1")
24731 (remove "true")))))
24733 (service pam-mount-service-type
24734 (pam-mount-configuration
24735 (rules pam-mount-rules)))
24738 The complete list of possible options can be found in the man page for
24739 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
24744 @node Guix Services
24745 @subsection Guix Services
24747 @subsubheading Guix Data Service
24748 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
24749 and provides data about GNU Guix. This includes information about
24750 packages, derivations and lint warnings.
24752 The data is stored in a PostgreSQL database, and available through a web
24755 @defvar {Scheme Variable} guix-data-service-type
24756 Service type for the Guix Data Service. Its value must be a
24757 @code{guix-data-service-configuration} object. The service optionally
24758 extends the getmail service, as the guix-commits mailing list is used to
24759 find out about changes in the Guix git repository.
24762 @deftp {Data Type} guix-data-service-configuration
24763 Data type representing the configuration of the Guix Data Service.
24766 @item @code{package} (default: @code{guix-data-service})
24767 The Guix Data Service package to use.
24769 @item @code{user} (default: @code{"guix-data-service"})
24770 The system user to run the service as.
24772 @item @code{group} (default: @code{"guix-data-service"})
24773 The system group to run the service as.
24775 @item @code{port} (default: @code{8765})
24776 The port to bind the web service to.
24778 @item @code{host} (default: @code{"127.0.0.1"})
24779 The host to bind the web service to.
24781 @item @code{getmail-idle-mailboxes} (default: @code{#f})
24782 If set, this is the list of mailboxes that the getmail service will be
24783 configured to listen to.
24785 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
24786 If set, this is the @code{getmail-retriever-configuration} object with
24787 which to configure getmail to fetch mail from the guix-commits mailing
24794 @node Miscellaneous Services
24795 @subsection Miscellaneous Services
24797 @cindex fingerprint
24798 @subsubheading Fingerprint Service
24800 The @code{(gnu services authentication)} module provides a DBus service to
24801 read and identify fingerprints via a fingerprint sensor.
24803 @defvr {Scheme Variable} fprintd-service-type
24804 The service type for @command{fprintd}, which provides the fingerprint
24805 reading capability.
24808 (service fprintd-service-type)
24813 @subsubheading System Control Service
24815 The @code{(gnu services sysctl)} provides a service to configure kernel
24816 parameters at boot.
24818 @defvr {Scheme Variable} sysctl-service-type
24819 The service type for @command{sysctl}, which modifies kernel parameters
24820 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
24824 (service sysctl-service-type
24825 (sysctl-configuration
24826 (settings '(("net.ipv4.ip_forward" . "1")))))
24830 @deftp {Data Type} sysctl-configuration
24831 The data type representing the configuration of @command{sysctl}.
24834 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
24835 The @command{sysctl} executable to use.
24837 @item @code{settings} (default: @code{'()})
24838 An association list specifies kernel parameters and their values.
24843 @subsubheading PC/SC Smart Card Daemon Service
24845 The @code{(gnu services security-token)} module provides the following service
24846 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
24847 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
24848 manager that coordinates communications with smart card readers, smart cards
24849 and cryptographic tokens that are connected to the system.
24851 @defvr {Scheme Variable} pcscd-service-type
24852 Service type for the @command{pcscd} service. Its value must be a
24853 @code{pcscd-configuration} object. To run pcscd in the default
24854 configuration, instantiate it as:
24857 (service pcscd-service-type)
24861 @deftp {Data Type} pcscd-configuration
24862 The data type representing the configuration of @command{pcscd}.
24865 @item @code{pcsc-lite} (default: @code{pcsc-lite})
24866 The pcsc-lite package that provides pcscd.
24867 @item @code{usb-drivers} (default: @code{(list ccid)})
24868 List of packages that provide USB drivers to pcscd. Drivers are expected to be
24869 under @file{pcsc/drivers} in the store directory of the package.
24874 @subsubheading Lirc Service
24876 The @code{(gnu services lirc)} module provides the following service.
24878 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
24879 [#:device #f] [#:driver #f] [#:config-file #f] @
24880 [#:extra-options '()]
24881 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
24882 decodes infrared signals from remote controls.
24884 Optionally, @var{device}, @var{driver} and @var{config-file}
24885 (configuration file name) may be specified. See @command{lircd} manual
24888 Finally, @var{extra-options} is a list of additional command-line options
24889 passed to @command{lircd}.
24893 @subsubheading Spice Service
24895 The @code{(gnu services spice)} module provides the following service.
24897 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
24898 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
24899 that enables sharing the clipboard with a vm and setting the guest display
24900 resolution when the graphical console window resizes.
24903 @cindex inputattach
24904 @subsubheading inputattach Service
24906 @cindex tablet input, for Xorg
24907 @cindex touchscreen input, for Xorg
24908 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
24909 use input devices such as Wacom tablets, touchscreens, or joysticks with the
24910 Xorg display server.
24912 @deffn {Scheme Variable} inputattach-service-type
24913 Type of a service that runs @command{inputattach} on a device and
24914 dispatches events from it.
24917 @deftp {Data Type} inputattach-configuration
24919 @item @code{device-type} (default: @code{"wacom"})
24920 The type of device to connect to. Run @command{inputattach --help}, from the
24921 @code{inputattach} package, to see the list of supported device types.
24923 @item @code{device} (default: @code{"/dev/ttyS0"})
24924 The device file to connect to the device.
24926 @item @code{baud-rate} (default: @code{#f})
24927 Baud rate to use for the serial connection.
24928 Should be a number or @code{#f}.
24930 @item @code{log-file} (default: @code{#f})
24931 If true, this must be the name of a file to log messages to.
24935 @subsection Dictionary Services
24937 The @code{(gnu services dict)} module provides the following service:
24939 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
24940 Return a service that runs the @command{dicod} daemon, an implementation
24941 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
24943 The optional @var{config} argument specifies the configuration for
24944 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
24945 default it serves the GNU Collaborative International Dictonary of English.
24947 You can add @command{open localhost} to your @file{~/.dico} file to make
24948 @code{localhost} the default server for @command{dico} client
24949 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
24952 @deftp {Data Type} dicod-configuration
24953 Data type representing the configuration of dicod.
24956 @item @code{dico} (default: @var{dico})
24957 Package object of the GNU Dico dictionary server.
24959 @item @code{interfaces} (default: @var{'("localhost")})
24960 This is the list of IP addresses and ports and possibly socket file
24961 names to listen to (@pxref{Server Settings, @code{listen} directive,,
24962 dico, GNU Dico Manual}).
24964 @item @code{handlers} (default: @var{'()})
24965 List of @code{<dicod-handler>} objects denoting handlers (module instances).
24967 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
24968 List of @code{<dicod-database>} objects denoting dictionaries to be served.
24972 @deftp {Data Type} dicod-handler
24973 Data type representing a dictionary handler (module instance).
24977 Name of the handler (module instance).
24979 @item @code{module} (default: @var{#f})
24980 Name of the dicod module of the handler (instance). If it is @code{#f},
24981 the module has the same name as the handler.
24982 (@pxref{Modules,,, dico, GNU Dico Manual}).
24984 @item @code{options}
24985 List of strings or gexps representing the arguments for the module handler
24989 @deftp {Data Type} dicod-database
24990 Data type representing a dictionary database.
24994 Name of the database, will be used in DICT commands.
24996 @item @code{handler}
24997 Name of the dicod handler (module instance) used by this database
24998 (@pxref{Handlers,,, dico, GNU Dico Manual}).
25000 @item @code{complex?} (default: @var{#f})
25001 Whether the database configuration complex. The complex configuration
25002 will need a corresponding @code{<dicod-handler>} object, otherwise not.
25004 @item @code{options}
25005 List of strings or gexps representing the arguments for the database
25006 (@pxref{Databases,,, dico, GNU Dico Manual}).
25010 @defvr {Scheme Variable} %dicod-database:gcide
25011 A @code{<dicod-database>} object serving the GNU Collaborative International
25012 Dictionary of English using the @code{gcide} package.
25015 The following is an example @code{dicod-service} configuration.
25018 (dicod-service #:config
25019 (dicod-configuration
25020 (handlers (list (dicod-handler
25024 (list #~(string-append "dbdir=" #$wordnet))))))
25025 (databases (list (dicod-database
25028 (handler "wordnet")
25029 (options '("database=wn")))
25030 %dicod-database:gcide))))
25034 @subsubheading Docker Service
25036 The @code{(gnu services docker)} module provides the following services.
25038 @defvr {Scheme Variable} docker-service-type
25040 This is the type of the service that runs @url{https://www.docker.com,Docker},
25041 a daemon that can execute application bundles (sometimes referred to as
25042 ``containers'') in isolated environments.
25046 @deftp {Data Type} docker-configuration
25047 This is the data type representing the configuration of Docker and Containerd.
25051 @item @code{package} (default: @code{docker})
25052 The Docker package to use.
25054 @item @code{containerd} (default: @var{containerd})
25055 The Containerd package to use.
25061 @subsubheading Auditd Service
25063 The @code{(gnu services auditd)} module provides the following service.
25065 @defvr {Scheme Variable} auditd-service-type
25067 This is the type of the service that runs
25068 @url{https://people.redhat.com/sgrubb/audit/,auditd},
25069 a daemon that tracks security-relevant information on your system.
25071 Examples of things that can be tracked:
25081 Failed login attempts
25088 @command{auditctl} from the @code{audit} package can be used in order
25089 to add or remove events to be tracked (until the next reboot).
25090 In order to permanently track events, put the command line arguments
25091 of auditctl into @file{/etc/audit/audit.rules}.
25092 @command{aureport} from the @code{audit} package can be used in order
25093 to view a report of all recorded events.
25094 The audit daemon usually logs into the directory @file{/var/log/audit}.
25098 @deftp {Data Type} auditd-configuration
25099 This is the data type representing the configuration of auditd.
25103 @item @code{audit} (default: @code{audit})
25104 The audit package to use.
25109 @defvr {Scheme Variable} singularity-service-type
25110 This is the type of the service that allows you to run
25111 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
25112 create and run application bundles (aka. ``containers''). The value for this
25113 service is the Singularity package to use.
25115 The service does not install a daemon; instead, it installs helper programs as
25116 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
25117 @command{singularity run} and similar commands.
25121 @subsubheading Nix service
25123 The @code{(gnu services nix)} module provides the following service.
25125 @defvr {Scheme Variable} nix-service-type
25127 This is the type of the service that runs build daemon of the
25128 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
25132 (use-modules (gnu))
25133 (use-service-modules nix)
25134 (use-package-modules package-management)
25138 (packages (append (list nix)
25141 (services (append (list (service nix-service-type))
25145 After @command{guix system reconfigure} configure Nix for your user:
25148 @item Add a Nix channel and update it. See
25149 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
25151 @item Create a symlink to your profile and activate Nix profile:
25155 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
25156 $ source /run/current-system/profile/etc/profile.d/nix.sh
25161 @node Setuid Programs
25162 @section Setuid Programs
25164 @cindex setuid programs
25165 Some programs need to run with ``root'' privileges, even when they are
25166 launched by unprivileged users. A notorious example is the
25167 @command{passwd} program, which users can run to change their
25168 password, and which needs to access the @file{/etc/passwd} and
25169 @file{/etc/shadow} files---something normally restricted to root, for
25170 obvious security reasons. To address that, these executables are
25171 @dfn{setuid-root}, meaning that they always run with root privileges
25172 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
25173 for more info about the setuid mechanism.)
25175 The store itself @emph{cannot} contain setuid programs: that would be a
25176 security issue since any user on the system can write derivations that
25177 populate the store (@pxref{The Store}). Thus, a different mechanism is
25178 used: instead of changing the setuid bit directly on files that are in
25179 the store, we let the system administrator @emph{declare} which programs
25180 should be setuid root.
25182 The @code{setuid-programs} field of an @code{operating-system}
25183 declaration contains a list of G-expressions denoting the names of
25184 programs to be setuid-root (@pxref{Using the Configuration System}).
25185 For instance, the @command{passwd} program, which is part of the Shadow
25186 package, can be designated by this G-expression (@pxref{G-Expressions}):
25189 #~(string-append #$shadow "/bin/passwd")
25192 A default set of setuid programs is defined by the
25193 @code{%setuid-programs} variable of the @code{(gnu system)} module.
25195 @defvr {Scheme Variable} %setuid-programs
25196 A list of G-expressions denoting common programs that are setuid-root.
25198 The list includes commands such as @command{passwd}, @command{ping},
25199 @command{su}, and @command{sudo}.
25202 Under the hood, the actual setuid programs are created in the
25203 @file{/run/setuid-programs} directory at system activation time. The
25204 files in this directory refer to the ``real'' binaries, which are in the
25207 @node X.509 Certificates
25208 @section X.509 Certificates
25210 @cindex HTTPS, certificates
25211 @cindex X.509 certificates
25213 Web servers available over HTTPS (that is, HTTP over the transport-layer
25214 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
25215 that the client can then use to @emph{authenticate} the server. To do
25216 that, clients verify that the server's certificate is signed by a
25217 so-called @dfn{certificate authority} (CA). But to verify the CA's
25218 signature, clients must have first acquired the CA's certificate.
25220 Web browsers such as GNU@tie{}IceCat include their own set of CA
25221 certificates, such that they are able to verify CA signatures
25224 However, most other programs that can talk HTTPS---@command{wget},
25225 @command{git}, @command{w3m}, etc.---need to be told where CA
25226 certificates can be found.
25228 @cindex @code{nss-certs}
25229 In Guix, this is done by adding a package that provides certificates
25230 to the @code{packages} field of the @code{operating-system} declaration
25231 (@pxref{operating-system Reference}). Guix includes one such package,
25232 @code{nss-certs}, which is a set of CA certificates provided as part of
25233 Mozilla's Network Security Services.
25235 Note that it is @emph{not} part of @code{%base-packages}, so you need to
25236 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
25237 most applications and libraries look for certificates by default, points
25238 to the certificates installed globally.
25240 Unprivileged users, including users of Guix on a foreign distro,
25241 can also install their own certificate package in
25242 their profile. A number of environment variables need to be defined so
25243 that applications and libraries know where to find them. Namely, the
25244 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
25245 variables. Some applications add their own environment variables; for
25246 instance, the Git version control system honors the certificate bundle
25247 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
25248 would typically run something like:
25251 $ guix install nss-certs
25252 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
25253 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25254 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
25257 As another example, R requires the @code{CURL_CA_BUNDLE} environment
25258 variable to point to a certificate bundle, so you would have to run
25259 something like this:
25262 $ guix install nss-certs
25263 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25266 For other applications you may want to look up the required environment
25267 variable in the relevant documentation.
25270 @node Name Service Switch
25271 @section Name Service Switch
25273 @cindex name service switch
25275 The @code{(gnu system nss)} module provides bindings to the
25276 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
25277 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
25278 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
25279 extended with new ``name'' lookup methods for system databases, which
25280 includes host names, service names, user accounts, and more (@pxref{Name
25281 Service Switch, System Databases and Name Service Switch,, libc, The GNU
25282 C Library Reference Manual}).
25284 The NSS configuration specifies, for each system database, which lookup
25285 method is to be used, and how the various methods are chained
25286 together---for instance, under which circumstances NSS should try the
25287 next method in the list. The NSS configuration is given in the
25288 @code{name-service-switch} field of @code{operating-system} declarations
25289 (@pxref{operating-system Reference, @code{name-service-switch}}).
25292 @cindex .local, host name lookup
25293 As an example, the declaration below configures the NSS to use the
25294 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
25295 back-end}, which supports host name lookups over multicast DNS (mDNS)
25296 for host names ending in @code{.local}:
25299 (name-service-switch
25300 (hosts (list %files ;first, check /etc/hosts
25302 ;; If the above did not succeed, try
25303 ;; with 'mdns_minimal'.
25305 (name "mdns_minimal")
25307 ;; 'mdns_minimal' is authoritative for
25308 ;; '.local'. When it returns "not found",
25309 ;; no need to try the next methods.
25310 (reaction (lookup-specification
25311 (not-found => return))))
25313 ;; Then fall back to DNS.
25317 ;; Finally, try with the "full" 'mdns'.
25322 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
25323 contains this configuration, so you will not have to type it if all you
25324 want is to have @code{.local} host lookup working.
25326 Note that, in this case, in addition to setting the
25327 @code{name-service-switch} of the @code{operating-system} declaration,
25328 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
25329 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
25330 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
25331 to the name service cache daemon (@pxref{Base Services,
25332 @code{nscd-service}}).
25334 For convenience, the following variables provide typical NSS
25337 @defvr {Scheme Variable} %default-nss
25338 This is the default name service switch configuration, a
25339 @code{name-service-switch} object.
25342 @defvr {Scheme Variable} %mdns-host-lookup-nss
25343 This is the name service switch configuration with support for host name
25344 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
25347 The reference for name service switch configuration is given below. It
25348 is a direct mapping of the configuration file format of the C library , so
25349 please refer to the C library manual for more information (@pxref{NSS
25350 Configuration File,,, libc, The GNU C Library Reference Manual}).
25351 Compared to the configuration file format of libc NSS, it has the advantage
25352 not only of adding this warm parenthetic feel that we like, but also
25353 static checks: you will know about syntax errors and typos as soon as you
25354 run @command{guix system}.
25356 @deftp {Data Type} name-service-switch
25358 This is the data type representation the configuration of libc's name
25359 service switch (NSS). Each field below represents one of the supported
25376 The system databases handled by the NSS. Each of these fields must be a
25377 list of @code{<name-service>} objects (see below).
25381 @deftp {Data Type} name-service
25383 This is the data type representing an actual name service and the
25384 associated lookup action.
25388 A string denoting the name service (@pxref{Services in the NSS
25389 configuration,,, libc, The GNU C Library Reference Manual}).
25391 Note that name services listed here must be visible to nscd. This is
25392 achieved by passing the @code{#:name-services} argument to
25393 @code{nscd-service} the list of packages providing the needed name
25394 services (@pxref{Base Services, @code{nscd-service}}).
25397 An action specified using the @code{lookup-specification} macro
25398 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
25399 Reference Manual}). For example:
25402 (lookup-specification (unavailable => continue)
25403 (success => return))
25408 @node Initial RAM Disk
25409 @section Initial RAM Disk
25412 @cindex initial RAM disk
25413 For bootstrapping purposes, the Linux-Libre kernel is passed an
25414 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
25415 root file system as well as an initialization script. The latter is
25416 responsible for mounting the real root file system, and for loading any
25417 kernel modules that may be needed to achieve that.
25419 The @code{initrd-modules} field of an @code{operating-system}
25420 declaration allows you to specify Linux-libre kernel modules that must
25421 be available in the initrd. In particular, this is where you would list
25422 modules needed to actually drive the hard disk where your root partition
25423 is---although the default value of @code{initrd-modules} should cover
25424 most use cases. For example, assuming you need the @code{megaraid_sas}
25425 module in addition to the default modules to be able to access your root
25426 file system, you would write:
25431 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
25434 @defvr {Scheme Variable} %base-initrd-modules
25435 This is the list of kernel modules included in the initrd by default.
25438 Furthermore, if you need lower-level customization, the @code{initrd}
25439 field of an @code{operating-system} declaration allows
25440 you to specify which initrd you would like to use. The @code{(gnu
25441 system linux-initrd)} module provides three ways to build an initrd: the
25442 high-level @code{base-initrd} procedure and the low-level
25443 @code{raw-initrd} and @code{expression->initrd} procedures.
25445 The @code{base-initrd} procedure is intended to cover most common uses.
25446 For example, if you want to add a bunch of kernel modules to be loaded
25447 at boot time, you can define the @code{initrd} field of the operating
25448 system declaration like this:
25451 (initrd (lambda (file-systems . rest)
25452 ;; Create a standard initrd but set up networking
25453 ;; with the parameters QEMU expects by default.
25454 (apply base-initrd file-systems
25455 #:qemu-networking? #t
25459 The @code{base-initrd} procedure also handles common use cases that
25460 involves using the system as a QEMU guest, or as a ``live'' system with
25461 volatile root file system.
25463 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
25464 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
25465 such as trying to guess which kernel modules and packages should be included
25466 to the initrd. An example use of @code{raw-initrd} is when a user has
25467 a custom Linux kernel configuration and default kernel modules included by
25468 @code{base-initrd} are not available.
25470 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
25471 honors several options passed on the Linux kernel command line
25472 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
25473 @code{-append} option of QEMU), notably:
25476 @item --load=@var{boot}
25477 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
25478 program, once it has mounted the root file system.
25480 Guix uses this option to yield control to a boot program that runs the
25481 service activation programs and then spawns the GNU@tie{}Shepherd, the
25482 initialization system.
25484 @item --root=@var{root}
25485 Mount @var{root} as the root file system. @var{root} can be a
25486 device name like @code{/dev/sda1}, a file system label, or a file system
25489 @item --system=@var{system}
25490 Have @file{/run/booted-system} and @file{/run/current-system} point to
25493 @item modprobe.blacklist=@var{modules}@dots{}
25494 @cindex module, black-listing
25495 @cindex black list, of kernel modules
25496 Instruct the initial RAM disk as well as the @command{modprobe} command
25497 (from the kmod package) to refuse to load @var{modules}. @var{modules}
25498 must be a comma-separated list of module names---e.g.,
25499 @code{usbkbd,9pnet}.
25502 Start a read-eval-print loop (REPL) from the initial RAM disk before it
25503 tries to load kernel modules and to mount the root file system. Our
25504 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
25505 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
25506 Manual}, for more information on Guile's REPL.
25510 Now that you know all the features that initial RAM disks produced by
25511 @code{base-initrd} and @code{raw-initrd} provide,
25512 here is how to use it and customize it further.
25515 @cindex initial RAM disk
25516 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
25517 [#:linux-modules '()] [#:mapped-devices '()] @
25518 [#:keyboard-layout #f] @
25519 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
25520 Return a derivation that builds a raw initrd. @var{file-systems} is
25521 a list of file systems to be mounted by the initrd, possibly in addition to
25522 the root file system specified on the kernel command line via @code{--root}.
25523 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
25524 @var{mapped-devices} is a list of device mappings to realize before
25525 @var{file-systems} are mounted (@pxref{Mapped Devices}).
25526 @var{helper-packages} is a list of packages to be copied in the initrd. It may
25527 include @code{e2fsck/static} or other packages needed by the initrd to check
25528 the root file system.
25530 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25531 the desired console keyboard layout. This is done before @var{mapped-devices}
25532 are set up and before @var{file-systems} are mounted such that, should the
25533 user need to enter a passphrase or use the REPL, this happens using the
25534 intended keyboard layout.
25536 When @var{qemu-networking?} is true, set up networking with the standard QEMU
25537 parameters. When @var{virtio?} is true, load additional modules so that the
25538 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
25540 When @var{volatile-root?} is true, the root file system is writable but any changes
25544 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
25545 [#:mapped-devices '()] [#:keyboard-layout #f] @
25546 [#:qemu-networking? #f] [#:volatile-root? #f] @
25547 [#:linux-modules '()]
25548 Return as a file-like object a generic initrd, with kernel
25549 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
25550 mounted by the initrd, possibly in addition to the root file system specified
25551 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
25552 mappings to realize before @var{file-systems} are mounted.
25554 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25555 the desired console keyboard layout. This is done before @var{mapped-devices}
25556 are set up and before @var{file-systems} are mounted such that, should the
25557 user need to enter a passphrase or use the REPL, this happens using the
25558 intended keyboard layout.
25560 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
25562 The initrd is automatically populated with all the kernel modules necessary
25563 for @var{file-systems} and for the given options. Additional kernel
25564 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
25565 loaded at boot time in the order in which they appear.
25568 Needless to say, the initrds we produce and use embed a
25569 statically-linked Guile, and the initialization program is a Guile
25570 program. That gives a lot of flexibility. The
25571 @code{expression->initrd} procedure builds such an initrd, given the
25572 program to run in that initrd.
25574 @deffn {Scheme Procedure} expression->initrd @var{exp} @
25575 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
25576 Return as a file-like object a Linux initrd (a gzipped cpio archive)
25577 containing @var{guile} and that evaluates @var{exp}, a G-expression,
25578 upon booting. All the derivations referenced by @var{exp} are
25579 automatically copied to the initrd.
25582 @node Bootloader Configuration
25583 @section Bootloader Configuration
25586 @cindex boot loader
25588 The operating system supports multiple bootloaders. The bootloader is
25589 configured using @code{bootloader-configuration} declaration. All the
25590 fields of this structure are bootloader agnostic except for one field,
25591 @code{bootloader} that indicates the bootloader to be configured and
25594 Some of the bootloaders do not honor every field of
25595 @code{bootloader-configuration}. For instance, the extlinux
25596 bootloader does not support themes and thus ignores the @code{theme}
25599 @deftp {Data Type} bootloader-configuration
25600 The type of a bootloader configuration declaration.
25604 @item @code{bootloader}
25605 @cindex EFI, bootloader
25606 @cindex UEFI, bootloader
25607 @cindex BIOS, bootloader
25608 The bootloader to use, as a @code{bootloader} object. For now
25609 @code{grub-bootloader}, @code{grub-efi-bootloader},
25610 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
25612 @vindex grub-efi-bootloader
25613 @code{grub-efi-bootloader} allows to boot on modern systems using the
25614 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
25615 use if the installation image contains a @file{/sys/firmware/efi} directory
25616 when you boot it on your system.
25618 @vindex grub-bootloader
25619 @code{grub-bootloader} allows you to boot in particular Intel-based machines
25620 in ``legacy'' BIOS mode.
25622 @cindex ARM, bootloaders
25623 @cindex AArch64, bootloaders
25624 Available bootloaders are described in @code{(gnu bootloader @dots{})}
25625 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
25626 of bootloaders for a wide range of ARM and AArch64 systems, using the
25627 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
25629 @item @code{target}
25630 This is a string denoting the target onto which to install the
25633 The interpretation depends on the bootloader in question. For
25634 @code{grub-bootloader}, for example, it should be a device name understood by
25635 the bootloader @command{installer} command, such as @code{/dev/sda} or
25636 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
25637 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
25638 system, usually @file{/boot/efi}.
25640 @item @code{menu-entries} (default: @code{()})
25641 A possibly empty list of @code{menu-entry} objects (see below), denoting
25642 entries to appear in the bootloader menu, in addition to the current
25643 system entry and the entry pointing to previous system generations.
25645 @item @code{default-entry} (default: @code{0})
25646 The index of the default boot menu entry. Index 0 is for the entry of the
25649 @item @code{timeout} (default: @code{5})
25650 The number of seconds to wait for keyboard input before booting. Set to
25651 0 to boot immediately, and to -1 to wait indefinitely.
25653 @cindex keyboard layout, for the bootloader
25654 @item @code{keyboard-layout} (default: @code{#f})
25655 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
25656 layout, usually US@tie{}English (``qwerty'').
25658 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
25662 This option is currently ignored by bootloaders other than @code{grub} and
25666 @item @code{theme} (default: @var{#f})
25667 The bootloader theme object describing the theme to use. If no theme
25668 is provided, some bootloaders might use a default theme, that's true
25671 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
25672 The output terminals used for the bootloader boot menu, as a list of
25673 symbols. GRUB accepts the values: @code{console}, @code{serial},
25674 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
25675 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
25676 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
25677 configuration,,, grub,GNU GRUB manual}).
25679 @item @code{terminal-inputs} (default: @code{'()})
25680 The input terminals used for the bootloader boot menu, as a list of
25681 symbols. For GRUB, the default is the native platform terminal as
25682 determined at run-time. GRUB accepts the values: @code{console},
25683 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
25684 @code{usb_keyboard}. This field corresponds to the GRUB variable
25685 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
25688 @item @code{serial-unit} (default: @code{#f})
25689 The serial unit used by the bootloader, as an integer from 0 to 3.
25690 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
25691 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
25693 @item @code{serial-speed} (default: @code{#f})
25694 The speed of the serial interface, as an integer. For GRUB, the
25695 default value is chosen at run-time; currently GRUB chooses
25696 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
25703 Should you want to list additional boot menu entries @i{via} the
25704 @code{menu-entries} field above, you will need to create them with the
25705 @code{menu-entry} form. For example, imagine you want to be able to
25706 boot another distro (hard to imagine!), you can define a menu entry
25711 (label "The Other Distro")
25712 (linux "/boot/old/vmlinux-2.6.32")
25713 (linux-arguments '("root=/dev/sda2"))
25714 (initrd "/boot/old/initrd"))
25719 @deftp {Data Type} menu-entry
25720 The type of an entry in the bootloader menu.
25725 The label to show in the menu---e.g., @code{"GNU"}.
25728 The Linux kernel image to boot, for example:
25731 (file-append linux-libre "/bzImage")
25734 For GRUB, it is also possible to specify a device explicitly in the
25735 file path using GRUB's device naming convention (@pxref{Naming
25736 convention,,, grub, GNU GRUB manual}), for example:
25739 "(hd0,msdos1)/boot/vmlinuz"
25742 If the device is specified explicitly as above, then the @code{device}
25743 field is ignored entirely.
25745 @item @code{linux-arguments} (default: @code{()})
25746 The list of extra Linux kernel command-line arguments---e.g.,
25747 @code{("console=ttyS0")}.
25749 @item @code{initrd}
25750 A G-Expression or string denoting the file name of the initial RAM disk
25751 to use (@pxref{G-Expressions}).
25752 @item @code{device} (default: @code{#f})
25753 The device where the kernel and initrd are to be found---i.e., for GRUB,
25754 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
25756 This may be a file system label (a string), a file system UUID (a
25757 bytevector, @pxref{File Systems}), or @code{#f}, in which case
25758 the bootloader will search the device containing the file specified by
25759 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
25760 must @emph{not} be an OS device name such as @file{/dev/sda1}.
25765 @c FIXME: Write documentation once it's stable.
25766 For now only GRUB has theme support. GRUB themes are created using
25767 the @code{grub-theme} form, which is not documented yet.
25769 @defvr {Scheme Variable} %default-theme
25770 This is the default GRUB theme used by the operating system if no
25771 @code{theme} field is specified in @code{bootloader-configuration}
25774 It comes with a fancy background image displaying the GNU and Guix
25779 @node Invoking guix system
25780 @section Invoking @code{guix system}
25782 Once you have written an operating system declaration as seen in the
25783 previous section, it can be @dfn{instantiated} using the @command{guix
25784 system} command. The synopsis is:
25787 guix system @var{options}@dots{} @var{action} @var{file}
25790 @var{file} must be the name of a file containing an
25791 @code{operating-system} declaration. @var{action} specifies how the
25792 operating system is instantiated. Currently the following values are
25797 Display available service type definitions that match the given regular
25798 expressions, sorted by relevance:
25801 $ guix system search console font
25802 name: console-fonts
25803 location: gnu/services/base.scm:729:2
25804 extends: shepherd-root
25805 description: Install the given fonts on the specified ttys (fonts are
25806 + per virtual console on GNU/Linux). The value of this service is a list
25807 + of tty/font pairs like:
25809 + '(("tty1" . "LatGrkCyr-8x16"))
25813 location: gnu/services/base.scm:1048:2
25814 extends: shepherd-root
25815 description: Provide console login using the `mingetty' program.
25819 location: gnu/services/base.scm:775:2
25821 description: Provide a console log-in service as specified by its
25822 + configuration value, a `login-configuration' object.
25828 As for @command{guix package --search}, the result is written in
25829 @code{recutils} format, which makes it easy to filter the output
25830 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
25833 Build the operating system described in @var{file}, activate it, and
25834 switch to it@footnote{This action (and the related actions
25835 @code{switch-generation} and @code{roll-back}) are usable only on
25836 systems already running Guix System.}.
25838 This effects all the configuration specified in @var{file}: user
25839 accounts, system services, global package list, setuid programs, etc.
25840 The command starts system services specified in @var{file} that are not
25841 currently running; if a service is currently running this command will
25842 arrange for it to be upgraded the next time it is stopped (e.g.@: by
25843 @code{herd stop X} or @code{herd restart X}).
25845 This command creates a new generation whose number is one greater than
25846 the current generation (as reported by @command{guix system
25847 list-generations}). If that generation already exists, it will be
25848 overwritten. This behavior mirrors that of @command{guix package}
25849 (@pxref{Invoking guix package}).
25851 It also adds a bootloader menu entry for the new OS configuration,
25852 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
25853 entries for older configurations to a submenu, allowing you to choose
25854 an older system generation at boot time should you need it.
25857 @c The paragraph below refers to the problem discussed at
25858 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
25859 It is highly recommended to run @command{guix pull} once before you run
25860 @command{guix system reconfigure} for the first time (@pxref{Invoking
25861 guix pull}). Failing to do that you would see an older version of Guix
25862 once @command{reconfigure} has completed.
25865 @item switch-generation
25866 @cindex generations
25867 Switch to an existing system generation. This action atomically
25868 switches the system profile to the specified system generation. It
25869 also rearranges the system's existing bootloader menu entries. It
25870 makes the menu entry for the specified system generation the default,
25871 and it moves the entries for the other generatiors to a submenu, if
25872 supported by the bootloader being used. The next time the system
25873 boots, it will use the specified system generation.
25875 The bootloader itself is not being reinstalled when using this
25876 command. Thus, the installed bootloader is used with an updated
25877 configuration file.
25879 The target generation can be specified explicitly by its generation
25880 number. For example, the following invocation would switch to system
25884 guix system switch-generation 7
25887 The target generation can also be specified relative to the current
25888 generation with the form @code{+N} or @code{-N}, where @code{+3} means
25889 ``3 generations ahead of the current generation,'' and @code{-1} means
25890 ``1 generation prior to the current generation.'' When specifying a
25891 negative value such as @code{-1}, you must precede it with @code{--} to
25892 prevent it from being parsed as an option. For example:
25895 guix system switch-generation -- -1
25898 Currently, the effect of invoking this action is @emph{only} to switch
25899 the system profile to an existing generation and rearrange the
25900 bootloader menu entries. To actually start using the target system
25901 generation, you must reboot after running this action. In the future,
25902 it will be updated to do the same things as @command{reconfigure},
25903 like activating and deactivating services.
25905 This action will fail if the specified generation does not exist.
25908 @cindex rolling back
25909 Switch to the preceding system generation. The next time the system
25910 boots, it will use the preceding system generation. This is the inverse
25911 of @command{reconfigure}, and it is exactly the same as invoking
25912 @command{switch-generation} with an argument of @code{-1}.
25914 Currently, as with @command{switch-generation}, you must reboot after
25915 running this action to actually start using the preceding system
25918 @item delete-generations
25919 @cindex deleting system generations
25920 @cindex saving space
25921 Delete system generations, making them candidates for garbage collection
25922 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
25925 This works in the same way as @command{guix package --delete-generations}
25926 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
25927 arguments, all system generations but the current one are deleted:
25930 guix system delete-generations
25933 You can also select the generations you want to delete. The example below
25934 deletes all the system generations that are more than two month old:
25937 guix system delete-generations 2m
25940 Running this command automatically reinstalls the bootloader with an updated
25941 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
25942 longer lists the generations that have been deleted.
25945 Build the derivation of the operating system, which includes all the
25946 configuration files and programs needed to boot and run the system.
25947 This action does not actually install anything.
25950 Populate the given directory with all the files necessary to run the
25951 operating system specified in @var{file}. This is useful for first-time
25952 installations of Guix System. For instance:
25955 guix system init my-os-config.scm /mnt
25958 copies to @file{/mnt} all the store items required by the configuration
25959 specified in @file{my-os-config.scm}. This includes configuration
25960 files, packages, and so on. It also creates other essential files
25961 needed for the system to operate correctly---e.g., the @file{/etc},
25962 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
25964 This command also installs bootloader on the target specified in
25965 @file{my-os-config}, unless the @option{--no-bootloader} option was
25969 @cindex virtual machine
25971 @anchor{guix system vm}
25972 Build a virtual machine that contains the operating system declared in
25973 @var{file}, and return a script to run that virtual machine (VM).
25976 The @code{vm} action and others below
25977 can use KVM support in the Linux-libre kernel. Specifically, if the
25978 machine has hardware virtualization support, the corresponding
25979 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
25980 must exist and be readable and writable by the user and by the
25981 build users of the daemon (@pxref{Build Environment Setup}).
25984 Arguments given to the script are passed to QEMU as in the example
25985 below, which enables networking and requests 1@tie{}GiB of RAM for the
25989 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
25992 The VM shares its store with the host system.
25994 Additional file systems can be shared between the host and the VM using
25995 the @code{--share} and @code{--expose} command-line options: the former
25996 specifies a directory to be shared with write access, while the latter
25997 provides read-only access to the shared directory.
25999 The example below creates a VM in which the user's home directory is
26000 accessible read-only, and where the @file{/exchange} directory is a
26001 read-write mapping of @file{$HOME/tmp} on the host:
26004 guix system vm my-config.scm \
26005 --expose=$HOME --share=$HOME/tmp=/exchange
26008 On GNU/Linux, the default is to boot directly to the kernel; this has
26009 the advantage of requiring only a very tiny root disk image since the
26010 store of the host can then be mounted.
26012 The @code{--full-boot} option forces a complete boot sequence, starting
26013 with the bootloader. This requires more disk space since a root image
26014 containing at least the kernel, initrd, and bootloader data files must
26015 be created. The @code{--image-size} option can be used to specify the
26018 @cindex System images, creation in various formats
26019 @cindex Creating system images in various formats
26022 @itemx docker-image
26023 Return a virtual machine, disk image, or Docker image of the operating
26024 system declared in @var{file} that stands alone. By default,
26025 @command{guix system} estimates the size of the image needed to store
26026 the system, but you can use the @option{--image-size} option to specify
26027 a value. Docker images are built to contain exactly what they need, so
26028 the @option{--image-size} option is ignored in the case of
26029 @code{docker-image}.
26031 You can specify the root file system type by using the
26032 @option{--file-system-type} option. It defaults to @code{ext4}.
26034 When using @code{vm-image}, the returned image is in qcow2 format, which
26035 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
26036 for more information on how to run the image in a virtual machine.
26038 When using @code{disk-image}, a raw disk image is produced; it can be
26039 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
26040 the device corresponding to a USB stick, one can copy the image to it
26041 using the following command:
26044 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
26047 When using @code{docker-image}, a Docker image is produced. Guix builds
26048 the image from scratch, not from a pre-existing Docker base image. As a
26049 result, it contains @emph{exactly} what you define in the operating
26050 system configuration file. You can then load the image and launch a
26051 Docker container using commands like the following:
26054 image_id="`docker load < guix-system-docker-image.tar.gz`"
26055 container_id="`docker create $image_id`"
26056 docker start $container_id
26059 This command starts a new Docker container from the specified image. It
26060 will boot the Guix system in the usual manner, which means it will
26061 start any services you have defined in the operating system
26062 configuration. You can get an interactive shell running in the container
26063 using @command{docker exec}:
26066 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
26069 Depending on what you run in the Docker container, it
26070 may be necessary to give the container additional permissions. For
26071 example, if you intend to build software using Guix inside of the Docker
26072 container, you may need to pass the @option{--privileged} option to
26073 @code{docker create}.
26076 Return a script to run the operating system declared in @var{file}
26077 within a container. Containers are a set of lightweight isolation
26078 mechanisms provided by the kernel Linux-libre. Containers are
26079 substantially less resource-demanding than full virtual machines since
26080 the kernel, shared objects, and other resources can be shared with the
26081 host system; this also means they provide thinner isolation.
26083 Currently, the script must be run as root in order to support more than
26084 a single user and group. The container shares its store with the host
26087 As with the @code{vm} action (@pxref{guix system vm}), additional file
26088 systems to be shared between the host and container can be specified
26089 using the @option{--share} and @option{--expose} options:
26092 guix system container my-config.scm \
26093 --expose=$HOME --share=$HOME/tmp=/exchange
26097 This option requires Linux-libre 3.19 or newer.
26102 @var{options} can contain any of the common build options (@pxref{Common
26103 Build Options}). In addition, @var{options} can contain one of the
26107 @item --expression=@var{expr}
26108 @itemx -e @var{expr}
26109 Consider the operating-system @var{expr} evaluates to.
26110 This is an alternative to specifying a file which evaluates to an
26112 This is used to generate the Guix system installer @pxref{Building the
26113 Installation Image}).
26115 @item --system=@var{system}
26116 @itemx -s @var{system}
26117 Attempt to build for @var{system} instead of the host system type.
26118 This works as per @command{guix build} (@pxref{Invoking guix build}).
26122 Return the derivation file name of the given operating system without
26125 @item --file-system-type=@var{type}
26126 @itemx -t @var{type}
26127 For the @code{disk-image} action, create a file system of the given
26128 @var{type} on the image.
26130 When this option is omitted, @command{guix system} uses @code{ext4}.
26132 @cindex ISO-9660 format
26133 @cindex CD image format
26134 @cindex DVD image format
26135 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
26136 for burning on CDs and DVDs.
26138 @item --image-size=@var{size}
26139 For the @code{vm-image} and @code{disk-image} actions, create an image
26140 of the given @var{size}. @var{size} may be a number of bytes, or it may
26141 include a unit as a suffix (@pxref{Block size, size specifications,,
26142 coreutils, GNU Coreutils}).
26144 When this option is omitted, @command{guix system} computes an estimate
26145 of the image size as a function of the size of the system declared in
26150 For the @code{container} action, allow containers to access the host network,
26151 that is, do not create a network namespace.
26153 @item --root=@var{file}
26154 @itemx -r @var{file}
26155 Make @var{file} a symlink to the result, and register it as a garbage
26158 @item --skip-checks
26159 Skip pre-installation safety checks.
26161 By default, @command{guix system init} and @command{guix system
26162 reconfigure} perform safety checks: they make sure the file systems that
26163 appear in the @code{operating-system} declaration actually exist
26164 (@pxref{File Systems}), and that any Linux kernel modules that may be
26165 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
26166 RAM Disk}). Passing this option skips these tests altogether.
26169 @cindex on-error strategy
26170 @cindex error strategy
26171 @item --on-error=@var{strategy}
26172 Apply @var{strategy} when an error occurs when reading @var{file}.
26173 @var{strategy} may be one of the following:
26176 @item nothing-special
26177 Report the error concisely and exit. This is the default strategy.
26180 Likewise, but also display a backtrace.
26183 Report the error and enter Guile's debugger. From there, you can run
26184 commands such as @code{,bt} to get a backtrace, @code{,locals} to
26185 display local variable values, and more generally inspect the state of the
26186 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
26187 a list of available debugging commands.
26191 Once you have built, configured, re-configured, and re-re-configured
26192 your Guix installation, you may find it useful to list the operating
26193 system generations available on disk---and that you can choose from the
26194 bootloader boot menu:
26198 @item list-generations
26199 List a summary of each generation of the operating system available on
26200 disk, in a human-readable way. This is similar to the
26201 @option{--list-generations} option of @command{guix package}
26202 (@pxref{Invoking guix package}).
26204 Optionally, one can specify a pattern, with the same syntax that is used
26205 in @command{guix package --list-generations}, to restrict the list of
26206 generations displayed. For instance, the following command displays
26207 generations that are up to 10 days old:
26210 $ guix system list-generations 10d
26215 The @command{guix system} command has even more to offer! The following
26216 sub-commands allow you to visualize how your system services relate to
26219 @anchor{system-extension-graph}
26222 @item extension-graph
26223 Emit in Dot/Graphviz format to standard output the @dfn{service
26224 extension graph} of the operating system defined in @var{file}
26225 (@pxref{Service Composition}, for more information on service
26231 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
26234 produces a PDF file showing the extension relations among services.
26236 @anchor{system-shepherd-graph}
26237 @item shepherd-graph
26238 Emit in Dot/Graphviz format to standard output the @dfn{dependency
26239 graph} of shepherd services of the operating system defined in
26240 @var{file}. @xref{Shepherd Services}, for more information and for an
26245 @node Invoking guix deploy
26246 @section Invoking @code{guix deploy}
26248 We've already seen @code{operating-system} declarations used to manage a
26249 machine's configuration locally. Suppose you need to configure multiple
26250 machines, though---perhaps you're managing a service on the web that's
26251 comprised of several servers. @command{guix deploy} enables you to use those
26252 same @code{operating-system} declarations to manage multiple remote hosts at
26253 once as a logical ``deployment''.
26256 The functionality described in this section is still under development
26257 and is subject to change. Get in touch with us on
26258 @email{guix-devel@@gnu.org}!
26262 guix deploy @var{file}
26265 Such an invocation will deploy the machines that the code within @var{file}
26266 evaluates to. As an example, @var{file} might contain a definition like this:
26269 ;; This is a Guix deployment of a "bare bones" setup, with
26270 ;; no X11 display server, to a machine with an SSH daemon
26271 ;; listening on localhost:2222. A configuration such as this
26272 ;; may be appropriate for virtual machine with ports
26273 ;; forwarded to the host's loopback interface.
26275 (use-service-modules networking ssh)
26276 (use-package-modules bootloaders)
26280 (host-name "gnu-deployed")
26281 (timezone "Etc/UTC")
26282 (bootloader (bootloader-configuration
26283 (bootloader grub-bootloader)
26284 (target "/dev/vda")
26285 (terminal-outputs '(console))))
26286 (file-systems (cons (file-system
26288 (device "/dev/vda1")
26290 %base-file-systems))
26292 (append (list (service dhcp-client-service-type)
26293 (service openssh-service-type
26294 (openssh-configuration
26295 (permit-root-login #t)
26296 (allow-empty-passwords? #t))))
26300 (operating-system %system)
26301 (environment managed-host-environment-type)
26302 (configuration (machine-ssh-configuration
26303 (host-name "localhost")
26304 (system "x86_64-linux")
26306 (identity "./id_rsa")
26310 The file should evaluate to a list of @var{machine} objects. This example,
26311 upon being deployed, will create a new generation on the remote system
26312 realizing the @code{operating-system} declaration @var{%system}.
26313 @var{environment} and @var{configuration} specify how the machine should be
26314 provisioned---that is, how the computing resources should be created and
26315 managed. The above example does not create any resources, as a
26316 @code{'managed-host} is a machine that is already running the Guix system and
26317 available over the network. This is a particularly simple case; a more
26318 complex deployment may involve, for example, starting virtual machines through
26319 a Virtual Private Server (VPS) provider. In such a case, a different
26320 @var{environment} type would be used.
26322 Do note that you first need to generate a key pair on the coordinator machine
26323 to allow the daemon to export signed archives of files from the store
26324 (@pxref{Invoking guix archive}).
26327 # guix archive --generate-key
26331 Each target machine must authorize the key of the master machine so that it
26332 accepts store items it receives from the coordinator:
26335 # guix archive --authorize < coordinator-public-key.txt
26338 @code{user}, in this example, specifies the name of the user account to log in
26339 as to perform the deployment. Its default value is @code{root}, but root
26340 login over SSH may be forbidden in some cases. To work around this,
26341 @command{guix deploy} can log in as an unprivileged user and employ
26342 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
26343 currently installed on the remote and can be invoked non-interactively as
26344 @code{user}. That is: the line in @code{sudoers} granting @code{user} the
26345 ability to use @code{sudo} must contain the @code{NOPASSWD} tag.
26347 @deftp {Data Type} machine
26348 This is the data type representing a single machine in a heterogeneous Guix
26352 @item @code{operating-system}
26353 The object of the operating system configuration to deploy.
26355 @item @code{environment}
26356 An @code{environment-type} describing how the machine should be provisioned.
26358 @item @code{configuration} (default: @code{#f})
26359 An object describing the configuration for the machine's @code{environment}.
26360 If the @code{environment} has a default configuration, @code{#f} may be used.
26361 If @code{#f} is used for an environment with no default configuration,
26362 however, an error will be thrown.
26366 @deftp {Data Type} machine-ssh-configuration
26367 This is the data type representing the SSH client parameters for a machine
26368 with an @code{environment} of @code{managed-host-environment-type}.
26371 @item @code{host-name}
26372 @item @code{build-locally?} (default: @code{#t})
26373 If false, system derivations will be built on the machine being deployed to.
26374 @item @code{system}
26375 The system type describing the architecture of the machine being deployed
26376 to---e.g., @code{"x86_64-linux"}.
26377 @item @code{authorize?} (default: @code{#t})
26378 If true, the coordinator's signing key will be added to the remote's ACL
26380 @item @code{port} (default: @code{22})
26381 @item @code{user} (default: @code{"root"})
26382 @item @code{identity} (default: @code{#f})
26383 If specified, the path to the SSH private key to use to authenticate with the
26388 @deftp {Data Type} digital-ocean-configuration
26389 This is the data type describing the Droplet that should be created for a
26390 machine with an @code{environment} of @code{digital-ocean-environment-type}.
26393 @item @code{ssh-key}
26394 The path to the SSH private key to use to authenticate with the remote
26395 host. In the future, this field may not exist.
26397 A list of string ``tags'' that uniquely identify the machine. Must be given
26398 such that no two machines in the deployment have the same set of tags.
26399 @item @code{region}
26400 A Digital Ocean region slug, such as @code{"nyc3"}.
26402 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
26403 @item @code{enable-ipv6?}
26404 Whether or not the droplet should be created with IPv6 networking.
26408 @node Running Guix in a VM
26409 @section Running Guix in a Virtual Machine
26411 @cindex virtual machine
26412 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
26414 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
26415 This image is a compressed image in QCOW format. You will first need to
26416 decompress with @command{xz -d}, and then you can pass it to an emulator such
26417 as QEMU (see below for details).
26419 This image boots the Xfce graphical environment and it contains some
26420 commonly-used tools. You can install more software in the image by running
26421 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
26422 also reconfigure the system based on its initial configuration file available
26423 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
26425 Instead of using this pre-built image, one can also build their own virtual
26426 machine image using @command{guix system vm-image} (@pxref{Invoking guix
26427 system}). The returned image is in qcow2 format, which the
26428 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
26431 If you built your own image, you must copy it out of the store
26432 (@pxref{The Store}) and give yourself permission to write to the copy
26433 before you can use it. When invoking QEMU, you must choose a system
26434 emulator that is suitable for your hardware platform. Here is a minimal
26435 QEMU invocation that will boot the result of @command{guix system
26436 vm-image} on x86_64 hardware:
26439 $ qemu-system-x86_64 \
26440 -net user -net nic,model=virtio \
26441 -enable-kvm -m 1024 \
26442 -device virtio-blk,drive=myhd \
26443 -drive if=none,file=/tmp/qemu-image,id=myhd
26446 Here is what each of these options means:
26449 @item qemu-system-x86_64
26450 This specifies the hardware platform to emulate. This should match the
26454 Enable the unprivileged user-mode network stack. The guest OS can
26455 access the host but not vice versa. This is the simplest way to get the
26458 @item -net nic,model=virtio
26459 You must create a network interface of a given model. If you do not
26460 create a NIC, the boot will fail. Assuming your hardware platform is
26461 x86_64, you can get a list of available NIC models by running
26462 @command{qemu-system-x86_64 -net nic,model=help}.
26465 If your system has hardware virtualization extensions, enabling the
26466 virtual machine support (KVM) of the Linux kernel will make things run
26469 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
26471 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
26472 which may be insufficient for some operations.
26474 @item -device virtio-blk,drive=myhd
26475 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
26476 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
26477 better performance than if it were emulating a complete disk drive. See the
26478 QEMU and KVM documentation for more info.
26480 @item -drive if=none,file=/tmp/qemu-image,id=myhd
26481 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
26482 the ``myhd'' drive.
26485 The default @command{run-vm.sh} script that is returned by an invocation of
26486 @command{guix system vm} does not add a @command{-net user} flag by default.
26487 To get network access from within the vm add the @code{(dhcp-client-service)}
26488 to your system definition and start the VM using
26489 @command{`guix system vm config.scm` -net user}. An important caveat of using
26490 @command{-net user} for networking is that @command{ping} will not work, because
26491 it uses the ICMP protocol. You'll have to use a different command to check for
26492 network connectivity, for example @command{guix download}.
26494 @subsection Connecting Through SSH
26498 To enable SSH inside a VM you need to add an SSH server like
26499 @code{openssh-service-type} to your VM (@pxref{Networking Services,
26500 @code{openssh-service-type}}). In addition you need to forward the SSH port,
26501 22 by default, to the host. You can do this with
26504 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
26507 To connect to the VM you can run
26510 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
26513 The @command{-p} tells @command{ssh} the port you want to connect to.
26514 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
26515 every time you modify your @command{config.scm} file and the
26516 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
26517 connection to an unknown host every time you connect.
26519 @subsection Using @command{virt-viewer} with Spice
26521 As an alternative to the default @command{qemu} graphical client you can
26522 use the @command{remote-viewer} from the @command{virt-viewer} package. To
26523 connect pass the @command{-spice port=5930,disable-ticketing} flag to
26524 @command{qemu}. See previous section for further information on how to do this.
26526 Spice also allows you to do some nice stuff like share your clipboard with your
26527 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
26530 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
26531 -chardev spicevmc,name=vdagent,id=vdagent
26532 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
26533 name=com.redhat.spice.0
26536 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
26538 @node Defining Services
26539 @section Defining Services
26541 The previous sections show the available services and how one can combine
26542 them in an @code{operating-system} declaration. But how do we define
26543 them in the first place? And what is a service anyway?
26546 * Service Composition:: The model for composing services.
26547 * Service Types and Services:: Types and services.
26548 * Service Reference:: API reference.
26549 * Shepherd Services:: A particular type of service.
26552 @node Service Composition
26553 @subsection Service Composition
26557 Here we define a @dfn{service} as, broadly, something that extends the
26558 functionality of the operating system. Often a service is a process---a
26559 @dfn{daemon}---started when the system boots: a secure shell server, a
26560 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
26561 whose execution can be triggered by another daemon---e.g., an FTP server
26562 started by @command{inetd} or a D-Bus service activated by
26563 @command{dbus-daemon}. Occasionally, a service does not map to a
26564 daemon. For instance, the ``account'' service collects user accounts
26565 and makes sure they exist when the system runs; the ``udev'' service
26566 collects device management rules and makes them available to the eudev
26567 daemon; the @file{/etc} service populates the @file{/etc} directory
26570 @cindex service extensions
26571 Guix system services are connected by @dfn{extensions}. For instance, the
26572 secure shell service @emph{extends} the Shepherd---the
26573 initialization system, running as PID@tie{}1---by giving it the command
26574 lines to start and stop the secure shell daemon (@pxref{Networking
26575 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
26576 service by passing it its @file{.service} specification, and extends the
26577 udev service by passing it device management rules (@pxref{Desktop
26578 Services, @code{upower-service}}); the Guix daemon service extends the
26579 Shepherd by passing it the command lines to start and stop the daemon,
26580 and extends the account service by passing it a list of required build
26581 user accounts (@pxref{Base Services}).
26583 All in all, services and their ``extends'' relations form a directed
26584 acyclic graph (DAG). If we represent services as boxes and extensions
26585 as arrows, a typical system might provide something like this:
26587 @image{images/service-graph,,5in,Typical service extension graph.}
26589 @cindex system service
26590 At the bottom, we see the @dfn{system service}, which produces the
26591 directory containing everything to run and boot the system, as returned
26592 by the @command{guix system build} command. @xref{Service Reference},
26593 to learn about the other service types shown here.
26594 @xref{system-extension-graph, the @command{guix system extension-graph}
26595 command}, for information on how to generate this representation for a
26596 particular operating system definition.
26598 @cindex service types
26599 Technically, developers can define @dfn{service types} to express these
26600 relations. There can be any number of services of a given type on the
26601 system---for instance, a system running two instances of the GNU secure
26602 shell server (lsh) has two instances of @code{lsh-service-type}, with
26603 different parameters.
26605 The following section describes the programming interface for service
26606 types and services.
26608 @node Service Types and Services
26609 @subsection Service Types and Services
26611 A @dfn{service type} is a node in the DAG described above. Let us start
26612 with a simple example, the service type for the Guix build daemon
26613 (@pxref{Invoking guix-daemon}):
26616 (define guix-service-type
26620 (list (service-extension shepherd-root-service-type guix-shepherd-service)
26621 (service-extension account-service-type guix-accounts)
26622 (service-extension activation-service-type guix-activation)))
26623 (default-value (guix-configuration))))
26627 It defines three things:
26631 A name, whose sole purpose is to make inspection and debugging easier.
26634 A list of @dfn{service extensions}, where each extension designates the
26635 target service type and a procedure that, given the parameters of the
26636 service, returns a list of objects to extend the service of that type.
26638 Every service type has at least one service extension. The only
26639 exception is the @dfn{boot service type}, which is the ultimate service.
26642 Optionally, a default value for instances of this type.
26645 In this example, @code{guix-service-type} extends three services:
26648 @item shepherd-root-service-type
26649 The @code{guix-shepherd-service} procedure defines how the Shepherd
26650 service is extended. Namely, it returns a @code{<shepherd-service>}
26651 object that defines how @command{guix-daemon} is started and stopped
26652 (@pxref{Shepherd Services}).
26654 @item account-service-type
26655 This extension for this service is computed by @code{guix-accounts},
26656 which returns a list of @code{user-group} and @code{user-account}
26657 objects representing the build user accounts (@pxref{Invoking
26660 @item activation-service-type
26661 Here @code{guix-activation} is a procedure that returns a gexp, which is
26662 a code snippet to run at ``activation time''---e.g., when the service is
26666 A service of this type is instantiated like this:
26669 (service guix-service-type
26670 (guix-configuration
26672 (use-substitutes? #f)))
26675 The second argument to the @code{service} form is a value representing
26676 the parameters of this specific service instance.
26677 @xref{guix-configuration-type, @code{guix-configuration}}, for
26678 information about the @code{guix-configuration} data type. When the
26679 value is omitted, the default value specified by
26680 @code{guix-service-type} is used:
26683 (service guix-service-type)
26686 @code{guix-service-type} is quite simple because it extends other
26687 services but is not extensible itself.
26689 @c @subsubsubsection Extensible Service Types
26691 The service type for an @emph{extensible} service looks like this:
26694 (define udev-service-type
26695 (service-type (name 'udev)
26697 (list (service-extension shepherd-root-service-type
26698 udev-shepherd-service)))
26700 (compose concatenate) ;concatenate the list of rules
26701 (extend (lambda (config rules)
26703 (($ <udev-configuration> udev initial-rules)
26704 (udev-configuration
26705 (udev udev) ;the udev package to use
26706 (rules (append initial-rules rules)))))))))
26709 This is the service type for the
26710 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
26711 management daemon}. Compared to the previous example, in addition to an
26712 extension of @code{shepherd-root-service-type}, we see two new fields:
26716 This is the procedure to @dfn{compose} the list of extensions to
26717 services of this type.
26719 Services can extend the udev service by passing it lists of rules; we
26720 compose those extensions simply by concatenating them.
26723 This procedure defines how the value of the service is @dfn{extended} with
26724 the composition of the extensions.
26726 Udev extensions are composed into a list of rules, but the udev service
26727 value is itself a @code{<udev-configuration>} record. So here, we
26728 extend that record by appending the list of rules it contains to the
26729 list of contributed rules.
26732 This is a string giving an overview of the service type. The string can
26733 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
26734 @command{guix system search} command searches these strings and displays
26735 them (@pxref{Invoking guix system}).
26738 There can be only one instance of an extensible service type such as
26739 @code{udev-service-type}. If there were more, the
26740 @code{service-extension} specifications would be ambiguous.
26742 Still here? The next section provides a reference of the programming
26743 interface for services.
26745 @node Service Reference
26746 @subsection Service Reference
26748 We have seen an overview of service types (@pxref{Service Types and
26749 Services}). This section provides a reference on how to manipulate
26750 services and service types. This interface is provided by the
26751 @code{(gnu services)} module.
26753 @deffn {Scheme Procedure} service @var{type} [@var{value}]
26754 Return a new service of @var{type}, a @code{<service-type>} object (see
26755 below.) @var{value} can be any object; it represents the parameters of
26756 this particular service instance.
26758 When @var{value} is omitted, the default value specified by @var{type}
26759 is used; if @var{type} does not specify a default value, an error is
26762 For instance, this:
26765 (service openssh-service-type)
26769 is equivalent to this:
26772 (service openssh-service-type
26773 (openssh-configuration))
26776 In both cases the result is an instance of @code{openssh-service-type}
26777 with the default configuration.
26780 @deffn {Scheme Procedure} service? @var{obj}
26781 Return true if @var{obj} is a service.
26784 @deffn {Scheme Procedure} service-kind @var{service}
26785 Return the type of @var{service}---i.e., a @code{<service-type>} object.
26788 @deffn {Scheme Procedure} service-value @var{service}
26789 Return the value associated with @var{service}. It represents its
26793 Here is an example of how a service is created and manipulated:
26797 (service nginx-service-type
26798 (nginx-configuration
26800 (log-directory log-directory)
26801 (run-directory run-directory)
26802 (file config-file))))
26807 (eq? (service-kind s) nginx-service-type)
26811 The @code{modify-services} form provides a handy way to change the
26812 parameters of some of the services of a list such as
26813 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
26814 evaluates to a list of services. Of course, you could always use
26815 standard list combinators such as @code{map} and @code{fold} to do that
26816 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
26817 @code{modify-services} simply provides a more concise form for this
26820 @deffn {Scheme Syntax} modify-services @var{services} @
26821 (@var{type} @var{variable} => @var{body}) @dots{}
26823 Modify the services listed in @var{services} according to the given
26824 clauses. Each clause has the form:
26827 (@var{type} @var{variable} => @var{body})
26830 where @var{type} is a service type---e.g.,
26831 @code{guix-service-type}---and @var{variable} is an identifier that is
26832 bound within the @var{body} to the service parameters---e.g., a
26833 @code{guix-configuration} instance---of the original service of that
26836 The @var{body} should evaluate to the new service parameters, which will
26837 be used to configure the new service. This new service will replace the
26838 original in the resulting list. Because a service's service parameters
26839 are created using @code{define-record-type*}, you can write a succinct
26840 @var{body} that evaluates to the new service parameters by using the
26841 @code{inherit} feature that @code{define-record-type*} provides.
26843 @xref{Using the Configuration System}, for example usage.
26847 Next comes the programming interface for service types. This is
26848 something you want to know when writing new service definitions, but not
26849 necessarily when simply looking for ways to customize your
26850 @code{operating-system} declaration.
26852 @deftp {Data Type} service-type
26853 @cindex service type
26854 This is the representation of a @dfn{service type} (@pxref{Service Types
26859 This is a symbol, used only to simplify inspection and debugging.
26861 @item @code{extensions}
26862 A non-empty list of @code{<service-extension>} objects (see below).
26864 @item @code{compose} (default: @code{#f})
26865 If this is @code{#f}, then the service type denotes services that cannot
26866 be extended---i.e., services that do not receive ``values'' from other
26869 Otherwise, it must be a one-argument procedure. The procedure is called
26870 by @code{fold-services} and is passed a list of values collected from
26871 extensions. It may return any single value.
26873 @item @code{extend} (default: @code{#f})
26874 If this is @code{#f}, services of this type cannot be extended.
26876 Otherwise, it must be a two-argument procedure: @code{fold-services}
26877 calls it, passing it the initial value of the service as the first
26878 argument and the result of applying @code{compose} to the extension
26879 values as the second argument. It must return a value that is a valid
26880 parameter value for the service instance.
26883 @xref{Service Types and Services}, for examples.
26886 @deffn {Scheme Procedure} service-extension @var{target-type} @
26888 Return a new extension for services of type @var{target-type}.
26889 @var{compute} must be a one-argument procedure: @code{fold-services}
26890 calls it, passing it the value associated with the service that provides
26891 the extension; it must return a valid value for the target service.
26894 @deffn {Scheme Procedure} service-extension? @var{obj}
26895 Return true if @var{obj} is a service extension.
26898 Occasionally, you might want to simply extend an existing service. This
26899 involves creating a new service type and specifying the extension of
26900 interest, which can be verbose; the @code{simple-service} procedure
26901 provides a shorthand for this.
26903 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
26904 Return a service that extends @var{target} with @var{value}. This works
26905 by creating a singleton service type @var{name}, of which the returned
26906 service is an instance.
26908 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
26912 (simple-service 'my-mcron-job mcron-service-type
26913 #~(job '(next-hour (3)) "guix gc -F 2G"))
26917 At the core of the service abstraction lies the @code{fold-services}
26918 procedure, which is responsible for ``compiling'' a list of services
26919 down to a single directory that contains everything needed to boot and
26920 run the system---the directory shown by the @command{guix system build}
26921 command (@pxref{Invoking guix system}). In essence, it propagates
26922 service extensions down the service graph, updating each node parameters
26923 on the way, until it reaches the root node.
26925 @deffn {Scheme Procedure} fold-services @var{services} @
26926 [#:target-type @var{system-service-type}]
26927 Fold @var{services} by propagating their extensions down to the root of
26928 type @var{target-type}; return the root service adjusted accordingly.
26931 Lastly, the @code{(gnu services)} module also defines several essential
26932 service types, some of which are listed below.
26934 @defvr {Scheme Variable} system-service-type
26935 This is the root of the service graph. It produces the system directory
26936 as returned by the @command{guix system build} command.
26939 @defvr {Scheme Variable} boot-service-type
26940 The type of the ``boot service'', which produces the @dfn{boot script}.
26941 The boot script is what the initial RAM disk runs when booting.
26944 @defvr {Scheme Variable} etc-service-type
26945 The type of the @file{/etc} service. This service is used to create
26946 files under @file{/etc} and can be extended by
26947 passing it name/file tuples such as:
26950 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
26953 In this example, the effect would be to add an @file{/etc/issue} file
26954 pointing to the given file.
26957 @defvr {Scheme Variable} setuid-program-service-type
26958 Type for the ``setuid-program service''. This service collects lists of
26959 executable file names, passed as gexps, and adds them to the set of
26960 setuid-root programs on the system (@pxref{Setuid Programs}).
26963 @defvr {Scheme Variable} profile-service-type
26964 Type of the service that populates the @dfn{system profile}---i.e., the
26965 programs under @file{/run/current-system/profile}. Other services can
26966 extend it by passing it lists of packages to add to the system profile.
26970 @node Shepherd Services
26971 @subsection Shepherd Services
26973 @cindex shepherd services
26975 @cindex init system
26976 The @code{(gnu services shepherd)} module provides a way to define
26977 services managed by the GNU@tie{}Shepherd, which is the
26978 initialization system---the first process that is started when the
26979 system boots, also known as PID@tie{}1
26980 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
26982 Services in the Shepherd can depend on each other. For instance, the
26983 SSH daemon may need to be started after the syslog daemon has been
26984 started, which in turn can only happen once all the file systems have
26985 been mounted. The simple operating system defined earlier (@pxref{Using
26986 the Configuration System}) results in a service graph like this:
26988 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
26990 You can actually generate such a graph for any operating system
26991 definition using the @command{guix system shepherd-graph} command
26992 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
26994 The @code{%shepherd-root-service} is a service object representing
26995 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
26996 by passing it lists of @code{<shepherd-service>} objects.
26998 @deftp {Data Type} shepherd-service
26999 The data type representing a service managed by the Shepherd.
27002 @item @code{provision}
27003 This is a list of symbols denoting what the service provides.
27005 These are the names that may be passed to @command{herd start},
27006 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
27007 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
27008 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
27010 @item @code{requirement} (default: @code{'()})
27011 List of symbols denoting the Shepherd services this one depends on.
27013 @cindex one-shot services, for the Shepherd
27014 @item @code{one-shot?} (default: @code{#f})
27015 Whether this service is @dfn{one-shot}. One-shot services stop immediately
27016 after their @code{start} action has completed. @xref{Slots of services,,,
27017 shepherd, The GNU Shepherd Manual}, for more info.
27019 @item @code{respawn?} (default: @code{#t})
27020 Whether to restart the service when it stops, for instance when the
27021 underlying process dies.
27024 @itemx @code{stop} (default: @code{#~(const #f)})
27025 The @code{start} and @code{stop} fields refer to the Shepherd's
27026 facilities to start and stop processes (@pxref{Service De- and
27027 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
27028 G-expressions that get expanded in the Shepherd configuration file
27029 (@pxref{G-Expressions}).
27031 @item @code{actions} (default: @code{'()})
27032 @cindex actions, of Shepherd services
27033 This is a list of @code{shepherd-action} objects (see below) defining
27034 @dfn{actions} supported by the service, in addition to the standard
27035 @code{start} and @code{stop} actions. Actions listed here become available as
27036 @command{herd} sub-commands:
27039 herd @var{action} @var{service} [@var{arguments}@dots{}]
27042 @item @code{auto-start?} (default: @code{#t})
27043 Whether this service should be started automatically by the Shepherd. If it
27044 is @code{#f} the service has to be started manually with @code{herd start}.
27046 @item @code{documentation}
27047 A documentation string, as shown when running:
27050 herd doc @var{service-name}
27053 where @var{service-name} is one of the symbols in @code{provision}
27054 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
27056 @item @code{modules} (default: @code{%default-modules})
27057 This is the list of modules that must be in scope when @code{start} and
27058 @code{stop} are evaluated.
27063 @deftp {Data Type} shepherd-action
27064 This is the data type that defines additional actions implemented by a
27065 Shepherd service (see above).
27069 Symbol naming the action.
27071 @item documentation
27072 This is a documentation string for the action. It can be viewed by running:
27075 herd doc @var{service} action @var{action}
27079 This should be a gexp that evaluates to a procedure of at least one argument,
27080 which is the ``running value'' of the service (@pxref{Slots of services,,,
27081 shepherd, The GNU Shepherd Manual}).
27084 The following example defines an action called @code{say-hello} that kindly
27090 (documentation "Say hi!")
27091 (procedure #~(lambda (running . args)
27092 (format #t "Hello, friend! arguments: ~s\n"
27097 Assuming this action is added to the @code{example} service, then you can do:
27100 # herd say-hello example
27101 Hello, friend! arguments: ()
27102 # herd say-hello example a b c
27103 Hello, friend! arguments: ("a" "b" "c")
27106 This, as you can see, is a fairly sophisticated way to say hello.
27107 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
27111 @defvr {Scheme Variable} shepherd-root-service-type
27112 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
27114 This is the service type that extensions target when they want to create
27115 shepherd services (@pxref{Service Types and Services}, for an example).
27116 Each extension must pass a list of @code{<shepherd-service>}.
27119 @defvr {Scheme Variable} %shepherd-root-service
27120 This service represents PID@tie{}1.
27124 @node Documentation
27125 @chapter Documentation
27127 @cindex documentation, searching for
27128 @cindex searching for documentation
27129 @cindex Info, documentation format
27131 @cindex manual pages
27132 In most cases packages installed with Guix come with documentation.
27133 There are two main documentation formats: ``Info'', a browseable
27134 hypertext format used for GNU software, and ``manual pages'' (or ``man
27135 pages''), the linear documentation format traditionally found on Unix.
27136 Info manuals are accessed with the @command{info} command or with Emacs,
27137 and man pages are accessed using @command{man}.
27139 You can look for documentation of software installed on your system by
27140 keyword. For example, the following command searches for information
27141 about ``TLS'' in Info manuals:
27145 "(emacs)Network Security" -- STARTTLS
27146 "(emacs)Network Security" -- TLS
27147 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
27148 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
27153 The command below searches for the same keyword in man pages:
27157 SSL (7) - OpenSSL SSL/TLS library
27158 certtool (1) - GnuTLS certificate tool
27162 These searches are purely local to your computer so you have the
27163 guarantee that documentation you find corresponds to what you have
27164 actually installed, you can access it off-line, and your privacy is
27167 Once you have these results, you can view the relevant documentation by
27171 $ info "(gnutls)Core TLS API"
27181 Info manuals contain sections and indices as well as hyperlinks like
27182 those found in Web pages. The @command{info} reader (@pxref{Top, Info
27183 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
27184 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
27185 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
27186 Introduction}, for an introduction to Info navigation.
27188 @node Installing Debugging Files
27189 @chapter Installing Debugging Files
27191 @cindex debugging files
27192 Program binaries, as produced by the GCC compilers for instance, are
27193 typically written in the ELF format, with a section containing
27194 @dfn{debugging information}. Debugging information is what allows the
27195 debugger, GDB, to map binary code to source code; it is required to
27196 debug a compiled program in good conditions.
27198 The problem with debugging information is that is takes up a fair amount
27199 of disk space. For example, debugging information for the GNU C Library
27200 weighs in at more than 60 MiB. Thus, as a user, keeping all the
27201 debugging info of all the installed programs is usually not an option.
27202 Yet, space savings should not come at the cost of an impediment to
27203 debugging---especially in the GNU system, which should make it easier
27204 for users to exert their computing freedom (@pxref{GNU Distribution}).
27206 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
27207 mechanism that allows users to get the best of both worlds: debugging
27208 information can be stripped from the binaries and stored in separate
27209 files. GDB is then able to load debugging information from those files,
27210 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
27213 The GNU distribution takes advantage of this by storing debugging
27214 information in the @code{lib/debug} sub-directory of a separate package
27215 output unimaginatively called @code{debug} (@pxref{Packages with
27216 Multiple Outputs}). Users can choose to install the @code{debug} output
27217 of a package when they need it. For instance, the following command
27218 installs the debugging information for the GNU C Library and for GNU
27222 guix install glibc:debug guile:debug
27225 GDB must then be told to look for debug files in the user's profile, by
27226 setting the @code{debug-file-directory} variable (consider setting it
27227 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
27231 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
27234 From there on, GDB will pick up debugging information from the
27235 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
27237 In addition, you will most likely want GDB to be able to show the source
27238 code being debugged. To do that, you will have to unpack the source
27239 code of the package of interest (obtained with @code{guix build
27240 --source}, @pxref{Invoking guix build}), and to point GDB to that source
27241 directory using the @code{directory} command (@pxref{Source Path,
27242 @code{directory},, gdb, Debugging with GDB}).
27244 @c XXX: keep me up-to-date
27245 The @code{debug} output mechanism in Guix is implemented by the
27246 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
27247 opt-in---debugging information is available only for the packages
27248 with definitions explicitly declaring a @code{debug} output. This may be
27249 changed to opt-out in the future if our build farm servers can handle
27250 the load. To check whether a package has a @code{debug} output, use
27251 @command{guix package --list-available} (@pxref{Invoking guix package}).
27254 @node Security Updates
27255 @chapter Security Updates
27257 @cindex security updates
27258 @cindex security vulnerabilities
27259 Occasionally, important security vulnerabilities are discovered in software
27260 packages and must be patched. Guix developers try hard to keep track of
27261 known vulnerabilities and to apply fixes as soon as possible in the
27262 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
27263 containing only security updates.) The @command{guix lint} tool helps
27264 developers find out about vulnerable versions of software packages in the
27269 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
27270 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
27271 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
27275 @xref{Invoking guix lint}, for more information.
27277 Guix follows a functional
27278 package management discipline (@pxref{Introduction}), which implies
27279 that, when a package is changed, @emph{every package that depends on it}
27280 must be rebuilt. This can significantly slow down the deployment of
27281 fixes in core packages such as libc or Bash, since basically the whole
27282 distribution would need to be rebuilt. Using pre-built binaries helps
27283 (@pxref{Substitutes}), but deployment may still take more time than
27287 To address this, Guix implements @dfn{grafts}, a mechanism that allows
27288 for fast deployment of critical updates without the costs associated
27289 with a whole-distribution rebuild. The idea is to rebuild only the
27290 package that needs to be patched, and then to ``graft'' it onto packages
27291 explicitly installed by the user and that were previously referring to
27292 the original package. The cost of grafting is typically very low, and
27293 order of magnitudes lower than a full rebuild of the dependency chain.
27295 @cindex replacements of packages, for grafts
27296 For instance, suppose a security update needs to be applied to Bash.
27297 Guix developers will provide a package definition for the ``fixed''
27298 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
27299 Packages}). Then, the original package definition is augmented with a
27300 @code{replacement} field pointing to the package containing the bug fix:
27307 (replacement bash-fixed)))
27310 From there on, any package depending directly or indirectly on Bash---as
27311 reported by @command{guix gc --requisites} (@pxref{Invoking guix
27312 gc})---that is installed is automatically ``rewritten'' to refer to
27313 @code{bash-fixed} instead of @code{bash}. This grafting process takes
27314 time proportional to the size of the package, usually less than a
27315 minute for an ``average'' package on a recent machine. Grafting is
27316 recursive: when an indirect dependency requires grafting, then grafting
27317 ``propagates'' up to the package that the user is installing.
27319 Currently, the length of the name and version of the graft and that of
27320 the package it replaces (@code{bash-fixed} and @code{bash} in the example
27321 above) must be equal. This restriction mostly comes from the fact that
27322 grafting works by patching files, including binary files, directly.
27323 Other restrictions may apply: for instance, when adding a graft to a
27324 package providing a shared library, the original shared library and its
27325 replacement must have the same @code{SONAME} and be binary-compatible.
27327 The @option{--no-grafts} command-line option allows you to forcefully
27328 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
27332 guix build bash --no-grafts
27336 returns the store file name of the original Bash, whereas:
27343 returns the store file name of the ``fixed'', replacement Bash. This
27344 allows you to distinguish between the two variants of Bash.
27346 To verify which Bash your whole profile refers to, you can run
27347 (@pxref{Invoking guix gc}):
27350 guix gc -R `readlink -f ~/.guix-profile` | grep bash
27354 @dots{} and compare the store file names that you get with those above.
27355 Likewise for a complete Guix system generation:
27358 guix gc -R `guix system build my-config.scm` | grep bash
27361 Lastly, to check which Bash running processes are using, you can use the
27362 @command{lsof} command:
27365 lsof | grep /gnu/store/.*bash
27369 @node Bootstrapping
27370 @chapter Bootstrapping
27372 @c Adapted from the ELS 2013 paper.
27374 @cindex bootstrapping
27376 Bootstrapping in our context refers to how the distribution gets built
27377 ``from nothing''. Remember that the build environment of a derivation
27378 contains nothing but its declared inputs (@pxref{Introduction}). So
27379 there's an obvious chicken-and-egg problem: how does the first package
27380 get built? How does the first compiler get compiled? Note that this is
27381 a question of interest only to the curious hacker, not to the regular
27382 user, so you can shamelessly skip this section if you consider yourself
27383 a ``regular user''.
27385 @cindex bootstrap binaries
27386 The GNU system is primarily made of C code, with libc at its core. The
27387 GNU build system itself assumes the availability of a Bourne shell and
27388 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
27389 `grep'. Furthermore, build programs---programs that run
27390 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
27391 (@pxref{Derivations}). Consequently, to be able to build anything at
27392 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
27393 Binutils, libc, and the other packages mentioned above---the
27394 @dfn{bootstrap binaries}.
27396 These bootstrap binaries are ``taken for granted'', though we can also
27397 re-create them if needed (more on that later).
27399 For @code{i686-linux} and @code{x86_64-linux} the Guix bootstrap process is
27400 more elaborate, @pxref{Reduced Binary Seed Bootstrap}.
27403 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
27404 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
27407 @node Reduced Binary Seed Bootstrap
27408 @section The Reduced Binary Seed Bootstrap
27410 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
27411 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
27412 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
27413 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
27414 ``taken for granted.''
27416 Taking these binaries for granted means that we consider them to be a correct
27417 and trustworthy `seed' for building the complete system. Therein lies a
27418 problem: the current combined size of these bootstrap binaries is about 250MB
27419 (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing or even inspecting
27420 these is next to impossible.
27422 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a ``Reduced
27423 Binary Seed'' bootstrap @footnote{We would like to say: ``Full Source
27424 Bootstrap'' and while we are working towards that goal it would be hyperbole
27425 to use that term for what we do now.}.
27427 The Reduced Binary Seed bootstrap removes the most critical tools---from a
27428 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
27429 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
27430 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
27431 written in Scheme and the Mes C Library, built for TinyCC and for GCC). Using
27432 these new binary seeds and a new set of
27434 packages@footnote{@c
27449 gcc-mesboot1-wrapper,
27450 glibc-headers-mesboot,
27454 gcc-mesboot-wrapper.
27457 the ``missing'' Binutils, GCC, and the GNU C Library are built from source.
27458 From here on the more traditional bootstrap process resumes. This approach
27459 has reduced the bootstrap binaries in size to about 130MB. Work is ongoing to
27460 reduce this further. If you are interested, join us on @code{#bootstrappable}
27461 on the Freenode IRC network.
27463 @c ./pre-inst-env guix graph --type=bag -e '(begin (use-modules (guix packages)) (%current-system "i686-linux") (@@ (gnu packages commencement) gcc-mesboot))' > doc/images/gcc-mesboot-bag-graph.dot
27464 @c dot -T png doc/images/gcc-mesboot-bag-graph.dot > doc/images/gcc-mesboot-bag-graph.png
27466 Below is the generated dependency graph for @code{gcc-mesboot}, the bootstrap
27467 compiler used to build the rest of GuixSD.
27469 @image{images/gcc-mesboot-bag-graph,6in,,Dependency graph of the gcc-mesboot}
27471 @node Preparing to Use the Bootstrap Binaries
27472 @section Preparing to Use the Bootstrap Binaries
27474 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
27475 @c large image, it's hard to scroll. Oh well.
27476 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
27478 The figure above shows the very beginning of the dependency graph of the
27479 distribution, corresponding to the package definitions of the @code{(gnu
27480 packages bootstrap)} module. A similar figure can be generated with
27481 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
27484 guix graph -t derivation \
27485 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
27486 | dot -Tps > gcc.ps
27489 or, for the Reduced Binary Seed bootstrap
27492 guix graph -t derivation \
27493 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
27494 | dot -Tps > mes.ps
27497 At this level of detail, things are
27498 slightly complex. First, Guile itself consists of an ELF executable,
27499 along with many source and compiled Scheme files that are dynamically
27500 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
27501 tarball shown in this graph. This tarball is part of Guix's ``source''
27502 distribution, and gets inserted into the store with @code{add-to-store}
27503 (@pxref{The Store}).
27505 But how do we write a derivation that unpacks this tarball and adds it
27506 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
27507 derivation---the first one that gets built---uses @code{bash} as its
27508 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
27509 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
27510 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
27511 the Guix source distribution, whose sole purpose is to allow the Guile
27512 tarball to be unpacked.
27514 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
27515 Guile that can be used to run subsequent build programs. Its first task
27516 is to download tarballs containing the other pre-built binaries---this
27517 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
27518 @code{ftp-client.scm} are used for this purpose. The
27519 @code{module-import.drv} derivations import those modules in a directory
27520 in the store, using the original layout. The
27521 @code{module-import-compiled.drv} derivations compile those modules, and
27522 write them in an output directory with the right layout. This
27523 corresponds to the @code{#:modules} argument of
27524 @code{build-expression->derivation} (@pxref{Derivations}).
27526 Finally, the various tarballs are unpacked by the derivations
27527 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
27528 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
27529 point we have a working C tool chain.
27531 @unnumberedsec Building the Build Tools
27533 Bootstrapping is complete when we have a full tool chain that does not
27534 depend on the pre-built bootstrap tools discussed above. This
27535 no-dependency requirement is verified by checking whether the files of
27536 the final tool chain contain references to the @file{/gnu/store}
27537 directories of the bootstrap inputs. The process that leads to this
27538 ``final'' tool chain is described by the package definitions found in
27539 the @code{(gnu packages commencement)} module.
27541 The @command{guix graph} command allows us to ``zoom out'' compared to
27542 the graph above, by looking at the level of package objects instead of
27543 individual derivations---remember that a package may translate to
27544 several derivations, typically one derivation to download its source,
27545 one to build the Guile modules it needs, and one to actually build the
27546 package from source. The command:
27549 guix graph -t bag \
27550 -e '(@@@@ (gnu packages commencement)
27551 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
27555 produces the dependency graph leading to the ``final'' C
27556 library@footnote{You may notice the @code{glibc-intermediate} label,
27557 suggesting that it is not @emph{quite} final, but as a good
27558 approximation, we will consider it final.}, depicted below.
27560 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
27562 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
27563 The first tool that gets built with the bootstrap binaries is
27564 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
27565 for all the following packages. From there Findutils and Diffutils get
27568 Then come the first-stage Binutils and GCC, built as pseudo cross
27569 tools---i.e., with @code{--target} equal to @code{--host}. They are
27570 used to build libc. Thanks to this cross-build trick, this libc is
27571 guaranteed not to hold any reference to the initial tool chain.
27573 From there the final Binutils and GCC (not shown above) are built.
27575 from the final Binutils, and links programs against the just-built libc.
27576 This tool chain is used to build the other packages used by Guix and by
27577 the GNU Build System: Guile, Bash, Coreutils, etc.
27579 And voilà! At this point we have the complete set of build tools that
27580 the GNU Build System expects. These are in the @code{%final-inputs}
27581 variable of the @code{(gnu packages commencement)} module, and are
27582 implicitly used by any package that uses @code{gnu-build-system}
27583 (@pxref{Build Systems, @code{gnu-build-system}}).
27586 @unnumberedsec Building the Bootstrap Binaries
27588 @cindex bootstrap binaries
27589 Because the final tool chain does not depend on the bootstrap binaries,
27590 those rarely need to be updated. Nevertheless, it is useful to have an
27591 automated way to produce them, should an update occur, and this is what
27592 the @code{(gnu packages make-bootstrap)} module provides.
27594 The following command builds the tarballs containing the bootstrap binaries
27595 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
27596 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
27597 and Guile, and a tarball containing a mixture of Coreutils and other basic
27598 command-line tools):
27601 guix build bootstrap-tarballs
27604 The generated tarballs are those that should be referred to in the
27605 @code{(gnu packages bootstrap)} module mentioned at the beginning of
27608 Still here? Then perhaps by now you've started to wonder: when do we
27609 reach a fixed point? That is an interesting question! The answer is
27610 unknown, but if you would like to investigate further (and have
27611 significant computational and storage resources to do so), then let us
27614 @unnumberedsec Reducing the Set of Bootstrap Binaries
27616 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
27617 binary code! Why is that a problem? It's a problem because these big chunks
27618 of binary code are practically non-auditable, which makes it hard to establish
27619 what source code produced them. Every unauditable binary also leaves us
27620 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
27621 paper @emph{Reflections on Trusting Trust}.
27623 This is mitigated by the fact that our bootstrap binaries were generated
27624 from an earlier Guix revision. Nevertheless it lacks the level of
27625 transparency that we get in the rest of the package dependency graph,
27626 where Guix always gives us a source-to-binary mapping. Thus, our goal
27627 is to reduce the set of bootstrap binaries to the bare minimum.
27629 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
27630 on-going projects to do that. One of these is about replacing the
27631 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
27632 of increasing complexity, which could be built from source starting from
27633 a simple and auditable assembler.
27635 Our first major achievement is the replacement of of GCC, the GNU C Library
27636 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
27637 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
27638 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
27639 bootstrapped yet and thus we inject them as binary seeds. We call this the
27640 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
27641 binaries! Also, it has eliminated the C compiler binary; i686-linux and
27642 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
27644 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
27645 also looking at any other bootstrap binaries. Your help is welcome!
27648 @chapter Porting to a New Platform
27650 As discussed above, the GNU distribution is self-contained, and
27651 self-containment is achieved by relying on pre-built ``bootstrap
27652 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
27653 operating system kernel, CPU architecture, and application binary
27654 interface (ABI). Thus, to port the distribution to a platform that is
27655 not yet supported, one must build those bootstrap binaries, and update
27656 the @code{(gnu packages bootstrap)} module to use them on that platform.
27658 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
27659 When everything goes well, and assuming the GNU tool chain supports the
27660 target platform, this can be as simple as running a command like this
27664 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
27667 For this to work, the @code{glibc-dynamic-linker} procedure in
27668 @code{(gnu packages bootstrap)} must be augmented to return the right
27669 file name for libc's dynamic linker on that platform; likewise,
27670 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
27671 taught about the new platform.
27673 Once these are built, the @code{(gnu packages bootstrap)} module needs
27674 to be updated to refer to these binaries on the target platform. That
27675 is, the hashes and URLs of the bootstrap tarballs for the new platform
27676 must be added alongside those of the currently supported platforms. The
27677 bootstrap Guile tarball is treated specially: it is expected to be
27678 available locally, and @file{gnu/local.mk} has rules to download it for
27679 the supported architectures; a rule for the new platform must be added
27682 In practice, there may be some complications. First, it may be that the
27683 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
27684 above) is not recognized by all the GNU tools. Typically, glibc
27685 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
27686 configure flag (see @code{gcc.scm} for examples of how to handle this).
27687 Second, some of the required packages could fail to build for that
27688 platform. Lastly, the generated binaries could be broken for some
27691 @c *********************************************************************
27692 @include contributing.texi
27694 @c *********************************************************************
27695 @node Acknowledgments
27696 @chapter Acknowledgments
27698 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
27699 which was designed and
27700 implemented by Eelco Dolstra, with contributions from other people (see
27701 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
27702 management, and promoted unprecedented features, such as transactional
27703 package upgrades and rollbacks, per-user profiles, and referentially
27704 transparent build processes. Without this work, Guix would not exist.
27706 The Nix-based software distributions, Nixpkgs and NixOS, have also been
27707 an inspiration for Guix.
27709 GNU@tie{}Guix itself is a collective work with contributions from a
27710 number of people. See the @file{AUTHORS} file in Guix for more
27711 information on these fine people. The @file{THANKS} file lists people
27712 who have helped by reporting bugs, taking care of the infrastructure,
27713 providing artwork and themes, making suggestions, and more---thank you!
27716 @c *********************************************************************
27717 @node GNU Free Documentation License
27718 @appendix GNU Free Documentation License
27719 @cindex license, GNU Free Documentation License
27720 @include fdl-1.3.texi
27722 @c *********************************************************************
27723 @node Concept Index
27724 @unnumbered Concept Index
27727 @node Programming Index
27728 @unnumbered Programming Index
27729 @syncodeindex tp fn
27730 @syncodeindex vr fn
27735 @c Local Variables:
27736 @c ispell-local-dictionary: "american";